Nephrology

Humans have used salt for centuries, to preserve or cure food before refrigeration was readily available, and even as currency in some cultures. Though modern food preservation efforts have decreased our reliance on salt, we still heavily incorporate it as a flavor enhancer. 

It’s only relatively recently that we’ve begun limiting salt in our diets, as research has linked high sodium intake with chronic, preventable conditions like hypertension, heart disease, and kidney disease.
 

How to Recommend Restriction in a Helpful Way 

The US Department of Agriculture’s Dietary Guidelines for Americans recommends intake of no more than 2300 mg of sodium daily for adults and children aged 14 years or older. This echoes similar recommendations for people at risk for heart disease, kidney disease, and hypertension. However, the sodium intake of the average American still sits at a whopping 3400 mg daily. 

High sodium intake is primarily the result of modern commercial food processing. Food prepared outside the home accounts for up to 70% of sodium intake in the United States, whereas only about 10% comes from salt that is added to food either during or after cooking. For this reason, I hesitate to recommend withholding salt as a primary focus when counseling on a low-sodium diet. 

To many people, certain foods just taste better with salt. Many of my patients in the southern United States simply will not eat foods like eggs and tomatoes if they cannot salt them. We can spend every moment of patient interaction time explaining why excess sodium is unhealthy, but the fact remains that humans prefer food that tastes good. This is why I try to avoid counseling a “no-added-salt” diet; instead, I recommend a low-sodium diet with a focus on fresh, whole foods and limiting salt to only a few food items. 

Patients should be counseled to slowly restrict their salt intake and be made aware that doing so may increase the time it takes for their sensitivity to the taste of less salty foods to return. But it is also important for them to know that it will return. The surest way to kill progress is for an unprepared patient to believe that their food will taste bland forever. A prepared patient understands that their food may taste different for a couple of weeks, but that the change will not last forever.
 

Types of Salt 

I have often worked with patients who insist that their sodium intake is acceptable because they are using sea salt instead of table salt. This is the result of exceptional marketing and misinformation. 

Specialty salts like sea salt and Himalayan pink salt contain about 560 mg and 590 mg of sodium, respectively, per quarter teaspoon. These products do have a slightly different mineral content, with sea salt typically having a negligible amount of calcium, magnesium, or potassium. The very small amount of these minerals offers no obvious health benefits compared with more affordable table salt. 

The sodium content of iodized table salt is comparable to these products, with about 590 mg of sodium per quarter teaspoon. Though its high sodium content will put some practitioners off, it is also an excellent source of iodine, at about 75 mg per serving. It has been estimated that upward of 35% of the US population has iodine deficiency, most commonly due to pregnancy, avoidance of dairy products, increasing rates of vegetarianism, intake of highly processed foods, and avoidance of added salt. For this reason, and its relative affordability, I find table salt to be far more appropriate for the average American than specialty salts.
 

Salt Substitutes 

Monosodium glutamate (MSG). MSG was previously at the center of public health concern owing to reports of “Chinese restaurant syndrome” that have since been debunked. I often recommend MSG to people trying to decrease sodium intake because the US Food and Drug Administration has designated it as GRAS (“generally recognized as safe”), and it has about one quarter of the sodium content of table salt at 125 mg per quarter teaspoon. Its crystalline structure makes it a lower-sodium salt substitute in savory applications like soups, stews, and gravies. 

Hot sauce. These sauces are generally composed of peppers, vinegar, salt, and sugar. There may be some variation and occasionally added ingredients depending upon the brand. However, I find most hot sauces to be a low-sodium seasoning option that works especially well on proteins like eggs, chicken, and pork. 

Potassium-based substitutes. Salt alternatives such as Nu-Salt and Morton Salt Substitute are sodium-free options with a significant amount of potassium, at 525 mg per quarter-teaspoon serving. These alternatives may not be ideal for patients with kidney problems, but they can be very helpful for those with potassium deficiency. 

Herb-based seasonings. Garlic and onion powder are both sodium-free seasonings that many of my patients have found help to increase palatability while decreasing salt use. Black pepper; lemon and lime juice; salt-free herb mixes like Mrs. Dash; and spices like cumin, paprika, dill, chili powder, and ginger are also sodium-free or low-sodium alternatives that can help to alleviate blandness for someone new to a low-sodium diet. I recommend them often and use them in my own cooking at home.

Plant-based diet. If the goal of care is to improve cardiovascular or kidney health, then I find that working with patients to increase intake of plant foods to be a helpful option. This way of eating encourages replacing highly processed foods that may be high in sodium and sugar with plants that tend to be higher in potassium and calcium. The Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and other plant-based diets have been shown to increase cardiovascular and metabolic health by significantly decreasing serum lipids, blood pressure, and hemoglobin A1c and promoting weight loss. They have also been shown to increase the gut microbiome and promote increased cognitive function. 

I rarely encourage the use of added salt. However, research shows that putting down the salt shaker is probably not the most effective option to restrict sodium intake. For those who can cut back, these options can help keep food flavorful and patients compliant. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She has disclosed no relevant financial relationships.

A version of this article appeared on Medscape.com.

Humans have used salt for centuries, to preserve or cure food before refrigeration was readily available, and even as currency in some cultures. Though modern food preservation efforts have decreased our reliance on salt, we still heavily incorporate it as a flavor enhancer. 

It’s only relatively recently that we’ve begun limiting salt in our diets, as research has linked high sodium intake with chronic, preventable conditions like hypertension, heart disease, and kidney disease.
 

How to Recommend Restriction in a Helpful Way 

The US Department of Agriculture’s Dietary Guidelines for Americans recommends intake of no more than 2300 mg of sodium daily for adults and children aged 14 years or older. This echoes similar recommendations for people at risk for heart disease, kidney disease, and hypertension. However, the sodium intake of the average American still sits at a whopping 3400 mg daily. 

High sodium intake is primarily the result of modern commercial food processing. Food prepared outside the home accounts for up to 70% of sodium intake in the United States, whereas only about 10% comes from salt that is added to food either during or after cooking. For this reason, I hesitate to recommend withholding salt as a primary focus when counseling on a low-sodium diet. 

To many people, certain foods just taste better with salt. Many of my patients in the southern United States simply will not eat foods like eggs and tomatoes if they cannot salt them. We can spend every moment of patient interaction time explaining why excess sodium is unhealthy, but the fact remains that humans prefer food that tastes good. This is why I try to avoid counseling a “no-added-salt” diet; instead, I recommend a low-sodium diet with a focus on fresh, whole foods and limiting salt to only a few food items. 

Patients should be counseled to slowly restrict their salt intake and be made aware that doing so may increase the time it takes for their sensitivity to the taste of less salty foods to return. But it is also important for them to know that it will return. The surest way to kill progress is for an unprepared patient to believe that their food will taste bland forever. A prepared patient understands that their food may taste different for a couple of weeks, but that the change will not last forever.
 

Types of Salt 

I have often worked with patients who insist that their sodium intake is acceptable because they are using sea salt instead of table salt. This is the result of exceptional marketing and misinformation. 

Specialty salts like sea salt and Himalayan pink salt contain about 560 mg and 590 mg of sodium, respectively, per quarter teaspoon. These products do have a slightly different mineral content, with sea salt typically having a negligible amount of calcium, magnesium, or potassium. The very small amount of these minerals offers no obvious health benefits compared with more affordable table salt. 

The sodium content of iodized table salt is comparable to these products, with about 590 mg of sodium per quarter teaspoon. Though its high sodium content will put some practitioners off, it is also an excellent source of iodine, at about 75 mg per serving. It has been estimated that upward of 35% of the US population has iodine deficiency, most commonly due to pregnancy, avoidance of dairy products, increasing rates of vegetarianism, intake of highly processed foods, and avoidance of added salt. For this reason, and its relative affordability, I find table salt to be far more appropriate for the average American than specialty salts.
 

Salt Substitutes 

Monosodium glutamate (MSG). MSG was previously at the center of public health concern owing to reports of “Chinese restaurant syndrome” that have since been debunked. I often recommend MSG to people trying to decrease sodium intake because the US Food and Drug Administration has designated it as GRAS (“generally recognized as safe”), and it has about one quarter of the sodium content of table salt at 125 mg per quarter teaspoon. Its crystalline structure makes it a lower-sodium salt substitute in savory applications like soups, stews, and gravies. 

Hot sauce. These sauces are generally composed of peppers, vinegar, salt, and sugar. There may be some variation and occasionally added ingredients depending upon the brand. However, I find most hot sauces to be a low-sodium seasoning option that works especially well on proteins like eggs, chicken, and pork. 

Potassium-based substitutes. Salt alternatives such as Nu-Salt and Morton Salt Substitute are sodium-free options with a significant amount of potassium, at 525 mg per quarter-teaspoon serving. These alternatives may not be ideal for patients with kidney problems, but they can be very helpful for those with potassium deficiency. 

Herb-based seasonings. Garlic and onion powder are both sodium-free seasonings that many of my patients have found help to increase palatability while decreasing salt use. Black pepper; lemon and lime juice; salt-free herb mixes like Mrs. Dash; and spices like cumin, paprika, dill, chili powder, and ginger are also sodium-free or low-sodium alternatives that can help to alleviate blandness for someone new to a low-sodium diet. I recommend them often and use them in my own cooking at home.

Plant-based diet. If the goal of care is to improve cardiovascular or kidney health, then I find that working with patients to increase intake of plant foods to be a helpful option. This way of eating encourages replacing highly processed foods that may be high in sodium and sugar with plants that tend to be higher in potassium and calcium. The Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and other plant-based diets have been shown to increase cardiovascular and metabolic health by significantly decreasing serum lipids, blood pressure, and hemoglobin A1c and promoting weight loss. They have also been shown to increase the gut microbiome and promote increased cognitive function. 

I rarely encourage the use of added salt. However, research shows that putting down the salt shaker is probably not the most effective option to restrict sodium intake. For those who can cut back, these options can help keep food flavorful and patients compliant. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She has disclosed no relevant financial relationships.

A version of this article appeared on Medscape.com.

Humans have used salt for centuries, to preserve or cure food before refrigeration was readily available, and even as currency in some cultures. Though modern food preservation efforts have decreased our reliance on salt, we still heavily incorporate it as a flavor enhancer. 

It’s only relatively recently that we’ve begun limiting salt in our diets, as research has linked high sodium intake with chronic, preventable conditions like hypertension, heart disease, and kidney disease.
 

How to Recommend Restriction in a Helpful Way 

The US Department of Agriculture’s Dietary Guidelines for Americans recommends intake of no more than 2300 mg of sodium daily for adults and children aged 14 years or older. This echoes similar recommendations for people at risk for heart disease, kidney disease, and hypertension. However, the sodium intake of the average American still sits at a whopping 3400 mg daily. 

High sodium intake is primarily the result of modern commercial food processing. Food prepared outside the home accounts for up to 70% of sodium intake in the United States, whereas only about 10% comes from salt that is added to food either during or after cooking. For this reason, I hesitate to recommend withholding salt as a primary focus when counseling on a low-sodium diet. 

To many people, certain foods just taste better with salt. Many of my patients in the southern United States simply will not eat foods like eggs and tomatoes if they cannot salt them. We can spend every moment of patient interaction time explaining why excess sodium is unhealthy, but the fact remains that humans prefer food that tastes good. This is why I try to avoid counseling a “no-added-salt” diet; instead, I recommend a low-sodium diet with a focus on fresh, whole foods and limiting salt to only a few food items. 

Patients should be counseled to slowly restrict their salt intake and be made aware that doing so may increase the time it takes for their sensitivity to the taste of less salty foods to return. But it is also important for them to know that it will return. The surest way to kill progress is for an unprepared patient to believe that their food will taste bland forever. A prepared patient understands that their food may taste different for a couple of weeks, but that the change will not last forever.
 

Types of Salt 

I have often worked with patients who insist that their sodium intake is acceptable because they are using sea salt instead of table salt. This is the result of exceptional marketing and misinformation. 

Specialty salts like sea salt and Himalayan pink salt contain about 560 mg and 590 mg of sodium, respectively, per quarter teaspoon. These products do have a slightly different mineral content, with sea salt typically having a negligible amount of calcium, magnesium, or potassium. The very small amount of these minerals offers no obvious health benefits compared with more affordable table salt. 

The sodium content of iodized table salt is comparable to these products, with about 590 mg of sodium per quarter teaspoon. Though its high sodium content will put some practitioners off, it is also an excellent source of iodine, at about 75 mg per serving. It has been estimated that upward of 35% of the US population has iodine deficiency, most commonly due to pregnancy, avoidance of dairy products, increasing rates of vegetarianism, intake of highly processed foods, and avoidance of added salt. For this reason, and its relative affordability, I find table salt to be far more appropriate for the average American than specialty salts.
 

Salt Substitutes 

Monosodium glutamate (MSG). MSG was previously at the center of public health concern owing to reports of “Chinese restaurant syndrome” that have since been debunked. I often recommend MSG to people trying to decrease sodium intake because the US Food and Drug Administration has designated it as GRAS (“generally recognized as safe”), and it has about one quarter of the sodium content of table salt at 125 mg per quarter teaspoon. Its crystalline structure makes it a lower-sodium salt substitute in savory applications like soups, stews, and gravies. 

Hot sauce. These sauces are generally composed of peppers, vinegar, salt, and sugar. There may be some variation and occasionally added ingredients depending upon the brand. However, I find most hot sauces to be a low-sodium seasoning option that works especially well on proteins like eggs, chicken, and pork. 

Potassium-based substitutes. Salt alternatives such as Nu-Salt and Morton Salt Substitute are sodium-free options with a significant amount of potassium, at 525 mg per quarter-teaspoon serving. These alternatives may not be ideal for patients with kidney problems, but they can be very helpful for those with potassium deficiency. 

Herb-based seasonings. Garlic and onion powder are both sodium-free seasonings that many of my patients have found help to increase palatability while decreasing salt use. Black pepper; lemon and lime juice; salt-free herb mixes like Mrs. Dash; and spices like cumin, paprika, dill, chili powder, and ginger are also sodium-free or low-sodium alternatives that can help to alleviate blandness for someone new to a low-sodium diet. I recommend them often and use them in my own cooking at home.

Plant-based diet. If the goal of care is to improve cardiovascular or kidney health, then I find that working with patients to increase intake of plant foods to be a helpful option. This way of eating encourages replacing highly processed foods that may be high in sodium and sugar with plants that tend to be higher in potassium and calcium. The Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and other plant-based diets have been shown to increase cardiovascular and metabolic health by significantly decreasing serum lipids, blood pressure, and hemoglobin A1c and promoting weight loss. They have also been shown to increase the gut microbiome and promote increased cognitive function. 

I rarely encourage the use of added salt. However, research shows that putting down the salt shaker is probably not the most effective option to restrict sodium intake. For those who can cut back, these options can help keep food flavorful and patients compliant. 

Ms. Winfree is a renal dietitian in private practice in Mary Esther, Florida. She has disclosed no relevant financial relationships.

A version of this article appeared on Medscape.com.

Do drugs work better if taken by the clock?

A new analysis published in The Lancet journal’s eClinicalMedicine suggests: Yes, they do — if you consider the patient’s individual body clock. The study is the first to find that timing blood pressure drugs to a person’s personal “chronotype” — that is, whether they are a night owl or an early bird — may reduce the risk for a heart attack.

The findings represent a significant advance in the field of circadian medicine or “chronotherapy” — timing drug administration to circadian rhythms. A growing stack of research suggests this approach could reduce side effects and improve the effectiveness of a wide range of therapies, including vaccines, cancer treatments, and drugs for depression, glaucoma, pain, seizures, and other conditions. Still, despite decades of research, time of day is rarely considered in writing prescriptions.

“We are really just at the beginning of an exciting new way of looking at patient care,” said Kenneth A. Dyar, PhD, whose lab at Helmholtz Zentrum München’s Institute for Diabetes and Cancer focuses on metabolic physiology. Dr. Dyar is co-lead author of the new blood pressure analysis.

“Chronotherapy is a rapidly growing field,” he said, “and I suspect we are soon going to see more and more studies focused on ‘personalized chronotherapy,’ not only in hypertension but also potentially in other clinical areas.”
 

The ‘Missing Piece’ in Chronotherapy Research

Blood pressure drugs have long been chronotherapy’s battleground. After all, blood pressure follows a circadian rhythm, peaking in the morning and dropping at night.

That healthy overnight dip can disappear in people with diabetes, kidney disease, and obstructive sleep apnea. Some physicians have suggested a bed-time dose to restore that dip. But studies have had mixed results, so “take at bedtime” has become a less common recommendation in recent years.

But the debate continued. After a large 2019 Spanish study found that bedtime doses had benefits so big that the results drew questions, an even larger, 2022 randomized, controlled trial from the University of Dundee in Dundee, Scotland — called the TIME study — aimed to settle the question.

Researchers assigned over 21,000 people to take morning or night hypertension drugs for several years and found no difference in cardiovascular outcomes.

“We did this study thinking nocturnal blood pressure tablets might be better,” said Thomas MacDonald, MD, professor emeritus of clinical pharmacology and pharmacoepidemiology at the University of Dundee and principal investigator for the TIME study and the recent chronotype analysis. “But there was no difference for heart attacks, strokes, or vascular death.”

So, the researchers then looked at participants’ chronotypes, sorting outcomes based on whether the participants were late-to-bed, late-to-rise “night owls” or early-to-bed, early-to-rise “morning larks.”

Their analysis of these 5358 TIME participants found the following results: Risk for hospitalization for a heart attack was at least 34% lower for “owls” who took their drugs at bedtime. By contrast, owls’ heart attack risk was at least 62% higher with morning doses. For “larks,” the opposite was true. Morning doses were associated with an 11% lower heart attack risk and night doses with an 11% higher risk, according to supplemental data.

The personalized approach could explain why some previous chronotherapy studies have failed to show a benefit. Those studies did not individualize drug timing as this one did. But personalization could be key to circadian medicine’s success.

“Our ‘internal personal time’ appears to be an important variable to consider when dosing antihypertensives,” said co-lead author Filippo Pigazzani, MD, PhD, clinical senior lecturer and honorary consultant cardiologist at the University of Dundee School of Medicine. “Chronotherapy research has been going on for decades. We knew there was something important with time of day. But researchers haven’t considered the internal time of individual people. I think that is the missing piece.”

The analysis has several important limitations, the researchers said. A total of 95% of participants were White. And it was an observational study, not a true randomized comparison. “We started it late in the original TIME study,” Dr. MacDonald said. “You could argue we were reporting on those who survived long enough to get into the analysis.” More research is needed, they concluded.
 

Looking Beyond Blood Pressure

What about the rest of the body? “Almost all the cells of our body contain ‘circadian clocks’ that are synchronized by daily environmental cues, including light-dark, activity-rest, and feeding-fasting cycles,” said Dr. Dyar.

An estimated 50% of prescription drugs hit targets in the body that have circadian patterns. So, experts suspect that syncing a drug with a person’s body clock might increase effectiveness of many drugs.

A handful of US Food and Drug Administration–approved drugs already have time-of-day recommendations on the label for effectiveness or to limit side effects, including bedtime or evening for the insomnia drug Ambien, the HIV antiviral Atripla, and cholesterol-lowering Zocor. Others are intended to be taken with or after your last meal of the day, such as the long-acting insulin Levemir and the cardiovascular drug Xarelto. A morning recommendation comes with the proton pump inhibitor Nexium and the attention-deficit/hyperactivity disorder drug Ritalin.

Interest is expanding. About one third of the papers published about chronotherapy in the past 25 years have come out in the past 5 years. The May 2024 meeting of the Society for Research on Biological Rhythms featured a day-long session aimed at bringing clinicians up to speed. An organization called the International Association of Circadian Health Clinics is trying to bring circadian medicine findings to clinicians and their patients and to support research.

Moreover, while recent research suggests minding the clock could have benefits for a wide range of treatments, ignoring it could cause problems.

In a Massachusetts Institute of Technology study published in April in Science Advances, researchers looked at engineered livers made from human donor cells and found more than 300 genes that operate on a circadian schedule, many with roles in drug metabolism. They also found that circadian patterns affected the toxicity of acetaminophen and atorvastatin. Identifying the time of day to take these drugs could maximize effectiveness and minimize adverse effects, the researchers said.
 

Timing and the Immune System

Circadian rhythms are also seen in immune processes. In a 2023 study in The Journal of Clinical Investigation of vaccine data from 1.5 million people in Israel, researchers found that children and older adults who got their second dose of the Pfizer mRNA COVID vaccine earlier in the day were about 36% less likely to be hospitalized with SARS-CoV-2 infection than those who got an evening shot.

“The sweet spot in our data was somewhere around late morning to late afternoon,” said lead researcher Jeffrey Haspel, MD, PhD, associate professor of medicine in the division of pulmonary and critical care medicine at Washington University School of Medicine in St. Louis.

In a multicenter, 2024 analysis of 13 studies of immunotherapy for advanced cancers in 1663 people, researchers found treatment earlier in the day was associated with longer survival time and longer survival without cancer progression.

“Patients with selected metastatic cancers seemed to largely benefit from early [time of day] infusions, which is consistent with circadian mechanisms in immune-cell functions and trafficking,” the researchers noted. But “retrospective randomized trials are needed to establish recommendations for optimal circadian timing.”

Other research suggests or is investigating possible chronotherapy benefits for depression, glaucoma, respiratory diseases, stroke treatment, epilepsy, and sedatives used in surgery. So why aren’t healthcare providers adding time of day to more prescriptions? “What’s missing is more reliable data,” Dr. Dyar said.
 

Should You Use Chronotherapy Now?

Experts emphasize that more research is needed before doctors use chronotherapy and before medical organizations include it in treatment recommendations. But for some patients, circadian dosing may be worth a try:

Night owls whose blood pressure isn’t well controlled. Dr. Dyar and Dr. Pigazzani said night-time blood pressure drugs may be helpful for people with a “late chronotype.” Of course, patients shouldn’t change their medication schedule on their own, they said. And doctors may want to consider other concerns, like more overnight bathroom visits with evening diuretics.

In their study, the researchers determined participants’ chronotype with a few questions from the Munich Chronotype Questionnaire about what time they fell asleep and woke up on workdays and days off and whether they considered themselves “morning types” or “evening types.” (The questions can be found in supplementary data for the study.)

If a physician thinks matching the timing of a dose with chronotype would help, they can consider it, Dr. Pigazzani said. “However, I must add that this was an observational study, so I would advise healthcare practitioners to wait for our data to be confirmed in new RCTs of personalized chronotherapy of hypertension.”

Children and older adults getting vaccines. Timing COVID shots and possibly other vaccines from late morning to mid-afternoon could have a small benefit for individuals and a bigger public-health benefit, Dr. Haspel said. But the most important thing is getting vaccinated. “If you can only get one in the evening, it’s still worthwhile. Timing may add oomph at a public-health level for more vulnerable groups.”
 

A version of this article appeared on Medscape.com.

Do drugs work better if taken by the clock?

A new analysis published in The Lancet journal’s eClinicalMedicine suggests: Yes, they do — if you consider the patient’s individual body clock. The study is the first to find that timing blood pressure drugs to a person’s personal “chronotype” — that is, whether they are a night owl or an early bird — may reduce the risk for a heart attack.

The findings represent a significant advance in the field of circadian medicine or “chronotherapy” — timing drug administration to circadian rhythms. A growing stack of research suggests this approach could reduce side effects and improve the effectiveness of a wide range of therapies, including vaccines, cancer treatments, and drugs for depression, glaucoma, pain, seizures, and other conditions. Still, despite decades of research, time of day is rarely considered in writing prescriptions.

“We are really just at the beginning of an exciting new way of looking at patient care,” said Kenneth A. Dyar, PhD, whose lab at Helmholtz Zentrum München’s Institute for Diabetes and Cancer focuses on metabolic physiology. Dr. Dyar is co-lead author of the new blood pressure analysis.

“Chronotherapy is a rapidly growing field,” he said, “and I suspect we are soon going to see more and more studies focused on ‘personalized chronotherapy,’ not only in hypertension but also potentially in other clinical areas.”
 

The ‘Missing Piece’ in Chronotherapy Research

Blood pressure drugs have long been chronotherapy’s battleground. After all, blood pressure follows a circadian rhythm, peaking in the morning and dropping at night.

That healthy overnight dip can disappear in people with diabetes, kidney disease, and obstructive sleep apnea. Some physicians have suggested a bed-time dose to restore that dip. But studies have had mixed results, so “take at bedtime” has become a less common recommendation in recent years.

But the debate continued. After a large 2019 Spanish study found that bedtime doses had benefits so big that the results drew questions, an even larger, 2022 randomized, controlled trial from the University of Dundee in Dundee, Scotland — called the TIME study — aimed to settle the question.

Researchers assigned over 21,000 people to take morning or night hypertension drugs for several years and found no difference in cardiovascular outcomes.

“We did this study thinking nocturnal blood pressure tablets might be better,” said Thomas MacDonald, MD, professor emeritus of clinical pharmacology and pharmacoepidemiology at the University of Dundee and principal investigator for the TIME study and the recent chronotype analysis. “But there was no difference for heart attacks, strokes, or vascular death.”

So, the researchers then looked at participants’ chronotypes, sorting outcomes based on whether the participants were late-to-bed, late-to-rise “night owls” or early-to-bed, early-to-rise “morning larks.”

Their analysis of these 5358 TIME participants found the following results: Risk for hospitalization for a heart attack was at least 34% lower for “owls” who took their drugs at bedtime. By contrast, owls’ heart attack risk was at least 62% higher with morning doses. For “larks,” the opposite was true. Morning doses were associated with an 11% lower heart attack risk and night doses with an 11% higher risk, according to supplemental data.

The personalized approach could explain why some previous chronotherapy studies have failed to show a benefit. Those studies did not individualize drug timing as this one did. But personalization could be key to circadian medicine’s success.

“Our ‘internal personal time’ appears to be an important variable to consider when dosing antihypertensives,” said co-lead author Filippo Pigazzani, MD, PhD, clinical senior lecturer and honorary consultant cardiologist at the University of Dundee School of Medicine. “Chronotherapy research has been going on for decades. We knew there was something important with time of day. But researchers haven’t considered the internal time of individual people. I think that is the missing piece.”

The analysis has several important limitations, the researchers said. A total of 95% of participants were White. And it was an observational study, not a true randomized comparison. “We started it late in the original TIME study,” Dr. MacDonald said. “You could argue we were reporting on those who survived long enough to get into the analysis.” More research is needed, they concluded.
 

Looking Beyond Blood Pressure

What about the rest of the body? “Almost all the cells of our body contain ‘circadian clocks’ that are synchronized by daily environmental cues, including light-dark, activity-rest, and feeding-fasting cycles,” said Dr. Dyar.

An estimated 50% of prescription drugs hit targets in the body that have circadian patterns. So, experts suspect that syncing a drug with a person’s body clock might increase effectiveness of many drugs.

A handful of US Food and Drug Administration–approved drugs already have time-of-day recommendations on the label for effectiveness or to limit side effects, including bedtime or evening for the insomnia drug Ambien, the HIV antiviral Atripla, and cholesterol-lowering Zocor. Others are intended to be taken with or after your last meal of the day, such as the long-acting insulin Levemir and the cardiovascular drug Xarelto. A morning recommendation comes with the proton pump inhibitor Nexium and the attention-deficit/hyperactivity disorder drug Ritalin.

Interest is expanding. About one third of the papers published about chronotherapy in the past 25 years have come out in the past 5 years. The May 2024 meeting of the Society for Research on Biological Rhythms featured a day-long session aimed at bringing clinicians up to speed. An organization called the International Association of Circadian Health Clinics is trying to bring circadian medicine findings to clinicians and their patients and to support research.

Moreover, while recent research suggests minding the clock could have benefits for a wide range of treatments, ignoring it could cause problems.

In a Massachusetts Institute of Technology study published in April in Science Advances, researchers looked at engineered livers made from human donor cells and found more than 300 genes that operate on a circadian schedule, many with roles in drug metabolism. They also found that circadian patterns affected the toxicity of acetaminophen and atorvastatin. Identifying the time of day to take these drugs could maximize effectiveness and minimize adverse effects, the researchers said.
 

Timing and the Immune System

Circadian rhythms are also seen in immune processes. In a 2023 study in The Journal of Clinical Investigation of vaccine data from 1.5 million people in Israel, researchers found that children and older adults who got their second dose of the Pfizer mRNA COVID vaccine earlier in the day were about 36% less likely to be hospitalized with SARS-CoV-2 infection than those who got an evening shot.

“The sweet spot in our data was somewhere around late morning to late afternoon,” said lead researcher Jeffrey Haspel, MD, PhD, associate professor of medicine in the division of pulmonary and critical care medicine at Washington University School of Medicine in St. Louis.

In a multicenter, 2024 analysis of 13 studies of immunotherapy for advanced cancers in 1663 people, researchers found treatment earlier in the day was associated with longer survival time and longer survival without cancer progression.

“Patients with selected metastatic cancers seemed to largely benefit from early [time of day] infusions, which is consistent with circadian mechanisms in immune-cell functions and trafficking,” the researchers noted. But “retrospective randomized trials are needed to establish recommendations for optimal circadian timing.”

Other research suggests or is investigating possible chronotherapy benefits for depression, glaucoma, respiratory diseases, stroke treatment, epilepsy, and sedatives used in surgery. So why aren’t healthcare providers adding time of day to more prescriptions? “What’s missing is more reliable data,” Dr. Dyar said.
 

Should You Use Chronotherapy Now?

Experts emphasize that more research is needed before doctors use chronotherapy and before medical organizations include it in treatment recommendations. But for some patients, circadian dosing may be worth a try:

Night owls whose blood pressure isn’t well controlled. Dr. Dyar and Dr. Pigazzani said night-time blood pressure drugs may be helpful for people with a “late chronotype.” Of course, patients shouldn’t change their medication schedule on their own, they said. And doctors may want to consider other concerns, like more overnight bathroom visits with evening diuretics.

In their study, the researchers determined participants’ chronotype with a few questions from the Munich Chronotype Questionnaire about what time they fell asleep and woke up on workdays and days off and whether they considered themselves “morning types” or “evening types.” (The questions can be found in supplementary data for the study.)

If a physician thinks matching the timing of a dose with chronotype would help, they can consider it, Dr. Pigazzani said. “However, I must add that this was an observational study, so I would advise healthcare practitioners to wait for our data to be confirmed in new RCTs of personalized chronotherapy of hypertension.”

Children and older adults getting vaccines. Timing COVID shots and possibly other vaccines from late morning to mid-afternoon could have a small benefit for individuals and a bigger public-health benefit, Dr. Haspel said. But the most important thing is getting vaccinated. “If you can only get one in the evening, it’s still worthwhile. Timing may add oomph at a public-health level for more vulnerable groups.”
 

A version of this article appeared on Medscape.com.

Do drugs work better if taken by the clock?

A new analysis published in The Lancet journal’s eClinicalMedicine suggests: Yes, they do — if you consider the patient’s individual body clock. The study is the first to find that timing blood pressure drugs to a person’s personal “chronotype” — that is, whether they are a night owl or an early bird — may reduce the risk for a heart attack.

The findings represent a significant advance in the field of circadian medicine or “chronotherapy” — timing drug administration to circadian rhythms. A growing stack of research suggests this approach could reduce side effects and improve the effectiveness of a wide range of therapies, including vaccines, cancer treatments, and drugs for depression, glaucoma, pain, seizures, and other conditions. Still, despite decades of research, time of day is rarely considered in writing prescriptions.

“We are really just at the beginning of an exciting new way of looking at patient care,” said Kenneth A. Dyar, PhD, whose lab at Helmholtz Zentrum München’s Institute for Diabetes and Cancer focuses on metabolic physiology. Dr. Dyar is co-lead author of the new blood pressure analysis.

“Chronotherapy is a rapidly growing field,” he said, “and I suspect we are soon going to see more and more studies focused on ‘personalized chronotherapy,’ not only in hypertension but also potentially in other clinical areas.”
 

The ‘Missing Piece’ in Chronotherapy Research

Blood pressure drugs have long been chronotherapy’s battleground. After all, blood pressure follows a circadian rhythm, peaking in the morning and dropping at night.

That healthy overnight dip can disappear in people with diabetes, kidney disease, and obstructive sleep apnea. Some physicians have suggested a bed-time dose to restore that dip. But studies have had mixed results, so “take at bedtime” has become a less common recommendation in recent years.

But the debate continued. After a large 2019 Spanish study found that bedtime doses had benefits so big that the results drew questions, an even larger, 2022 randomized, controlled trial from the University of Dundee in Dundee, Scotland — called the TIME study — aimed to settle the question.

Researchers assigned over 21,000 people to take morning or night hypertension drugs for several years and found no difference in cardiovascular outcomes.

“We did this study thinking nocturnal blood pressure tablets might be better,” said Thomas MacDonald, MD, professor emeritus of clinical pharmacology and pharmacoepidemiology at the University of Dundee and principal investigator for the TIME study and the recent chronotype analysis. “But there was no difference for heart attacks, strokes, or vascular death.”

So, the researchers then looked at participants’ chronotypes, sorting outcomes based on whether the participants were late-to-bed, late-to-rise “night owls” or early-to-bed, early-to-rise “morning larks.”

Their analysis of these 5358 TIME participants found the following results: Risk for hospitalization for a heart attack was at least 34% lower for “owls” who took their drugs at bedtime. By contrast, owls’ heart attack risk was at least 62% higher with morning doses. For “larks,” the opposite was true. Morning doses were associated with an 11% lower heart attack risk and night doses with an 11% higher risk, according to supplemental data.

The personalized approach could explain why some previous chronotherapy studies have failed to show a benefit. Those studies did not individualize drug timing as this one did. But personalization could be key to circadian medicine’s success.

“Our ‘internal personal time’ appears to be an important variable to consider when dosing antihypertensives,” said co-lead author Filippo Pigazzani, MD, PhD, clinical senior lecturer and honorary consultant cardiologist at the University of Dundee School of Medicine. “Chronotherapy research has been going on for decades. We knew there was something important with time of day. But researchers haven’t considered the internal time of individual people. I think that is the missing piece.”

The analysis has several important limitations, the researchers said. A total of 95% of participants were White. And it was an observational study, not a true randomized comparison. “We started it late in the original TIME study,” Dr. MacDonald said. “You could argue we were reporting on those who survived long enough to get into the analysis.” More research is needed, they concluded.
 

Looking Beyond Blood Pressure

What about the rest of the body? “Almost all the cells of our body contain ‘circadian clocks’ that are synchronized by daily environmental cues, including light-dark, activity-rest, and feeding-fasting cycles,” said Dr. Dyar.

An estimated 50% of prescription drugs hit targets in the body that have circadian patterns. So, experts suspect that syncing a drug with a person’s body clock might increase effectiveness of many drugs.

A handful of US Food and Drug Administration–approved drugs already have time-of-day recommendations on the label for effectiveness or to limit side effects, including bedtime or evening for the insomnia drug Ambien, the HIV antiviral Atripla, and cholesterol-lowering Zocor. Others are intended to be taken with or after your last meal of the day, such as the long-acting insulin Levemir and the cardiovascular drug Xarelto. A morning recommendation comes with the proton pump inhibitor Nexium and the attention-deficit/hyperactivity disorder drug Ritalin.

Interest is expanding. About one third of the papers published about chronotherapy in the past 25 years have come out in the past 5 years. The May 2024 meeting of the Society for Research on Biological Rhythms featured a day-long session aimed at bringing clinicians up to speed. An organization called the International Association of Circadian Health Clinics is trying to bring circadian medicine findings to clinicians and their patients and to support research.

Moreover, while recent research suggests minding the clock could have benefits for a wide range of treatments, ignoring it could cause problems.

In a Massachusetts Institute of Technology study published in April in Science Advances, researchers looked at engineered livers made from human donor cells and found more than 300 genes that operate on a circadian schedule, many with roles in drug metabolism. They also found that circadian patterns affected the toxicity of acetaminophen and atorvastatin. Identifying the time of day to take these drugs could maximize effectiveness and minimize adverse effects, the researchers said.
 

Timing and the Immune System

Circadian rhythms are also seen in immune processes. In a 2023 study in The Journal of Clinical Investigation of vaccine data from 1.5 million people in Israel, researchers found that children and older adults who got their second dose of the Pfizer mRNA COVID vaccine earlier in the day were about 36% less likely to be hospitalized with SARS-CoV-2 infection than those who got an evening shot.

“The sweet spot in our data was somewhere around late morning to late afternoon,” said lead researcher Jeffrey Haspel, MD, PhD, associate professor of medicine in the division of pulmonary and critical care medicine at Washington University School of Medicine in St. Louis.

In a multicenter, 2024 analysis of 13 studies of immunotherapy for advanced cancers in 1663 people, researchers found treatment earlier in the day was associated with longer survival time and longer survival without cancer progression.

“Patients with selected metastatic cancers seemed to largely benefit from early [time of day] infusions, which is consistent with circadian mechanisms in immune-cell functions and trafficking,” the researchers noted. But “retrospective randomized trials are needed to establish recommendations for optimal circadian timing.”

Other research suggests or is investigating possible chronotherapy benefits for depression, glaucoma, respiratory diseases, stroke treatment, epilepsy, and sedatives used in surgery. So why aren’t healthcare providers adding time of day to more prescriptions? “What’s missing is more reliable data,” Dr. Dyar said.
 

Should You Use Chronotherapy Now?

Experts emphasize that more research is needed before doctors use chronotherapy and before medical organizations include it in treatment recommendations. But for some patients, circadian dosing may be worth a try:

Night owls whose blood pressure isn’t well controlled. Dr. Dyar and Dr. Pigazzani said night-time blood pressure drugs may be helpful for people with a “late chronotype.” Of course, patients shouldn’t change their medication schedule on their own, they said. And doctors may want to consider other concerns, like more overnight bathroom visits with evening diuretics.

In their study, the researchers determined participants’ chronotype with a few questions from the Munich Chronotype Questionnaire about what time they fell asleep and woke up on workdays and days off and whether they considered themselves “morning types” or “evening types.” (The questions can be found in supplementary data for the study.)

If a physician thinks matching the timing of a dose with chronotype would help, they can consider it, Dr. Pigazzani said. “However, I must add that this was an observational study, so I would advise healthcare practitioners to wait for our data to be confirmed in new RCTs of personalized chronotherapy of hypertension.”

Children and older adults getting vaccines. Timing COVID shots and possibly other vaccines from late morning to mid-afternoon could have a small benefit for individuals and a bigger public-health benefit, Dr. Haspel said. But the most important thing is getting vaccinated. “If you can only get one in the evening, it’s still worthwhile. Timing may add oomph at a public-health level for more vulnerable groups.”
 

A version of this article appeared on Medscape.com.

TOPLINE:

Inebilizumab-cdon, a monoclonal antibody that depletes B cells, reduces the risk for flares without showing any new safety signals in patients with immunoglobulin G4-related disease (IgG4-RD) who have multiorgan disease and are on glucocorticoid therapy.

METHODOLOGY:

• IgG4-RD is an immune-mediated, fibroinflammatory condition that affects multiple organs, causing irreversible organ damage. MITIGATE is the first multinational, placebo-controlled trial involving patients with IgG4-RD.
• Researchers evaluated the efficacy and safety of inebilizumab in 135 adult patients at risk for flares due to a history of multiorgan disease and active disease requiring treatment with glucocorticoids.
• The patients were randomly assigned to receive 300-mg intravenous inebilizumab or placebo on day 1, day 15, and week 26.
• The primary endpoint was the time to the first treated and adjudicated IgG4-RD flare within 52 weeks.
• The secondary endpoints included the annualized flare rate, flare-free and treatment-free complete remission, and flare-free and corticosteroid-free complete remission.

TAKEAWAY:

• Compared with the placebo, inebilizumab reduced the risk for IgG4-RD flares by 87% during the 52-week trial period (hazard ratio, 0.13; P < .0001).
• All the secondary endpoints showed improvement following treatment with inebilizumab.
• The most common adverse reactions with inebilizumab, as observed in a previous trial for neuromyelitis optica spectrum disorder, were urinary tract infection and arthralgia.
• There were no new safety signals in the MITIGATE trial.

IN PRACTICE:

“These data mark a major milestone for the IgG4-RD community and provide substantial insight into not only how inebilizumab can help manage IgG4-RD but also key insights into the nature of this condition,” John Stone, MD, MPH, principal investigator, said in a news release.

SOURCE:

Dr. Stone, a professor of medicine at the Harvard Medical School and the Edward A. Fox Chair in Medicine at the Massachusetts General Hospital, Boston, led this study.

LIMITATIONS:

This press release did not discuss any limitations of the current study.

DISCLOSURES:

This study was funded by Mitsubishi Tanabe Pharma and Hansoh Pharma and sponsored by Amgen. The author disclosures were not available.

A version of this article appeared on Medscape.com.

TOPLINE:

Inebilizumab-cdon, a monoclonal antibody that depletes B cells, reduces the risk for flares without showing any new safety signals in patients with immunoglobulin G4-related disease (IgG4-RD) who have multiorgan disease and are on glucocorticoid therapy.

METHODOLOGY:

• IgG4-RD is an immune-mediated, fibroinflammatory condition that affects multiple organs, causing irreversible organ damage. MITIGATE is the first multinational, placebo-controlled trial involving patients with IgG4-RD.
• Researchers evaluated the efficacy and safety of inebilizumab in 135 adult patients at risk for flares due to a history of multiorgan disease and active disease requiring treatment with glucocorticoids.
• The patients were randomly assigned to receive 300-mg intravenous inebilizumab or placebo on day 1, day 15, and week 26.
• The primary endpoint was the time to the first treated and adjudicated IgG4-RD flare within 52 weeks.
• The secondary endpoints included the annualized flare rate, flare-free and treatment-free complete remission, and flare-free and corticosteroid-free complete remission.

TAKEAWAY:

• Compared with the placebo, inebilizumab reduced the risk for IgG4-RD flares by 87% during the 52-week trial period (hazard ratio, 0.13; P < .0001).
• All the secondary endpoints showed improvement following treatment with inebilizumab.
• The most common adverse reactions with inebilizumab, as observed in a previous trial for neuromyelitis optica spectrum disorder, were urinary tract infection and arthralgia.
• There were no new safety signals in the MITIGATE trial.

IN PRACTICE:

“These data mark a major milestone for the IgG4-RD community and provide substantial insight into not only how inebilizumab can help manage IgG4-RD but also key insights into the nature of this condition,” John Stone, MD, MPH, principal investigator, said in a news release.

SOURCE:

Dr. Stone, a professor of medicine at the Harvard Medical School and the Edward A. Fox Chair in Medicine at the Massachusetts General Hospital, Boston, led this study.

LIMITATIONS:

This press release did not discuss any limitations of the current study.

DISCLOSURES:

This study was funded by Mitsubishi Tanabe Pharma and Hansoh Pharma and sponsored by Amgen. The author disclosures were not available.

A version of this article appeared on Medscape.com.

TOPLINE:

Inebilizumab-cdon, a monoclonal antibody that depletes B cells, reduces the risk for flares without showing any new safety signals in patients with immunoglobulin G4-related disease (IgG4-RD) who have multiorgan disease and are on glucocorticoid therapy.

METHODOLOGY:

• IgG4-RD is an immune-mediated, fibroinflammatory condition that affects multiple organs, causing irreversible organ damage. MITIGATE is the first multinational, placebo-controlled trial involving patients with IgG4-RD.
• Researchers evaluated the efficacy and safety of inebilizumab in 135 adult patients at risk for flares due to a history of multiorgan disease and active disease requiring treatment with glucocorticoids.
• The patients were randomly assigned to receive 300-mg intravenous inebilizumab or placebo on day 1, day 15, and week 26.
• The primary endpoint was the time to the first treated and adjudicated IgG4-RD flare within 52 weeks.
• The secondary endpoints included the annualized flare rate, flare-free and treatment-free complete remission, and flare-free and corticosteroid-free complete remission.

TAKEAWAY:

• Compared with the placebo, inebilizumab reduced the risk for IgG4-RD flares by 87% during the 52-week trial period (hazard ratio, 0.13; P < .0001).
• All the secondary endpoints showed improvement following treatment with inebilizumab.
• The most common adverse reactions with inebilizumab, as observed in a previous trial for neuromyelitis optica spectrum disorder, were urinary tract infection and arthralgia.
• There were no new safety signals in the MITIGATE trial.

IN PRACTICE:

“These data mark a major milestone for the IgG4-RD community and provide substantial insight into not only how inebilizumab can help manage IgG4-RD but also key insights into the nature of this condition,” John Stone, MD, MPH, principal investigator, said in a news release.

SOURCE:

Dr. Stone, a professor of medicine at the Harvard Medical School and the Edward A. Fox Chair in Medicine at the Massachusetts General Hospital, Boston, led this study.

LIMITATIONS:

This press release did not discuss any limitations of the current study.

DISCLOSURES:

This study was funded by Mitsubishi Tanabe Pharma and Hansoh Pharma and sponsored by Amgen. The author disclosures were not available.

A version of this article appeared on Medscape.com.

STOCKHOLM — Improvements in kidney function outcomes observed with glucagon-like peptide-1 (GLP-1) receptor agonists in patients with type 2 diabetes extend to patients who are overweight or obese but don›t yet have type 2 diabetes, new research shows.

“These data are important because they are the first data to suggest a kidney benefit of semaglutide in this patient population in the absence of diabetes,” lead author Helen M. Colhoun, MD, of the Institute of Genetics and Cancer, University of Edinburgh, Scotland, United Kingdom, told this news organization.

“This is a population at high risk of chronic kidney disease with an increased need for kidney protection,” she said.

The late-breaking study was presented this week at the 61st European Renal Association (ERA) Congress 2024 and simultaneously published in Nature Medicine.
 

SELECT Trial Patients Without Diabetes

The findings are from a secondary analysis of the randomized SELECT (Semaglutide Effects on Heart Disease and Stroke in Patients With Overweight or Obesity) trial, which evaluated cardiovascular outcomes of semaglutide treatment among 17,604 adults with preexisting cardiovascular disease who were overweight or obese — but did not have diabetes.

For its primary endpoint, the trial showed semaglutide was associated with a 20% reduction in major adverse cardiovascular events compared with placebo.

With obesity also associated with a significantly increased risk of chronic kidney disease — and the headline-making FLOW trial, also presented at the congress, showing key benefits of semaglutide in improving kidney function in people with CKD and type 2 diabetes the secondary analysis of SELECT was conducted to investigate whether those kidney benefits extended to people without type 2 diabetes.

Patients were randomized 1:1 to once-weekly subcutaneous semaglutide at a dose of 2.4 mg or placebo. Baseline patient characteristics were well-balanced, including kidney function and albuminuria status.

The primary endpoint for the analysis was a nephropathy composite of time from randomization to the first occurrence of death from kidney causes; initiation of chronic kidney replacement therapy; onset of persistent estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m²; persistent ≥ 50% reduction in eGFR compared with baseline; or onset of persistent macroalbuminuria.

With a median follow-up of 182 weeks, the results showed that the semaglutide group was significantly less likely to develop the primary composite endpoint compared with the placebo group (1.8% vs 2.2%; hazard ratio [HR], 0.78; P = .02).

A significantly reduced decline in eGFR in the semaglutide group was observed at a prespecified 104-week time point, with a treatment effect of 0.75 mL/min/1.73 m² (P < .001), and the effect was more pronounced among participants with baseline eGFR < 60 mL/min/1.73 m² (P < .001). 

Furthermore, those in the semaglutide group had a significantly lower proportionate increase in urinary albumin-to-creatinine ratio (UACR) compared with placebo (–10.7%; P < .001) at the prespecified 104 weeks, with a net treatment benefit of –27.2% and –31.4% among those with randomization to UACR 30 to < 300 mg/g and 2300 mg/g, respectively.

Improvements varied according to baseline UACR status and were more pronounced among those with macroalbuminuria, at –8.1% for those with normoalbuminuria (n = 14,848), –27% for microalbuminuria (n = 1968), and –31% for macroalbuminuria (n = 325).

There were no reports of acute kidney injury associated with semaglutide, regardless of baseline eGFR. 

“We were hopeful that there would be similar benefits as those observed in the diabetes studies, but there are differences in kidney disease among those with and without type 2 diabetes, so we weren’t sure,” Dr. Colhoun told this news organization.
 

Benefits the Result of Weight Loss or Something Else?

Considering the beneficial effects of semaglutide on weight loss, underscored in an analysis also published this month that showed a mean 10.2% reduction in weight sustained for up to 4  years, a key question is whether the kidney benefits are a direct result of weight loss — or the drug mechanism or something else.

But Dr. Colhoun said the role of weight loss in terms of the kidney benefits is still uncertain, particularly considering the various other factors, including cardiometabolic improvements, which could also have an effect.

“It’s a very difficult question to answer,” she said. “We did do a mediation exploratory analysis suggesting a substantial part of the effect might be due to the weight change, but it’s difficult to demonstrate that because you have weight change going on in the placebo arm as well, but for different reasons,” she said.

“So, I would say the data suggest there is some component of this that is attributable to weight, but we certainly can’t attribute all of the [effects] to weight change.”

Small studies involving animals have shown a direct effect of semaglutide on kidney hemodynamics “but they’re small and not definitive,” Dr. Colhoun added.

And although weight loss achieved through other measures such as lifestyle changes show a small benefit on eGFR, “interestingly, those studies showed no effect at all on albuminuria, whereas we see a really substantial effect on albuminuria with semaglutide,” Dr. Colhoun said.

Studies of weight loss through bariatric surgery have shown kidney benefits; however, those were in the context of type 2 diabetes, unlike the current analysis.

In terms of whether the benefits may extend to tirzepatide, the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist, increasingly used in weight loss, results from another secondary analysis also show encouraging kidney benefits in people with type 2 diabetes, and there is ongoing research in patients with type 2 diabetes and those with obesity without diabetes, Dr. Colhoun noted.
 

Primary Prevention of CKD?

Limitations of the current analysis include that only about a fifth of participants in SELECT had an eGFR < 60  mL/min/1.73 m² or UACR ≥ 30 mg/g at baseline, suggesting a relatively low proportion of participants with kidney disease. 

Importantly, however, the kidney benefits observed in patients who are at such high risk of kidney disease but do not yet have diabetes or CKD, is encouraging, said Alberto Ortiz, MD, PhD, commenting on the study. Dr. Ortiz is chief of nephrology and the Hypertension Renal Unit, Health Research Institute of the Jiménez Díaz Foundation, Madrid, Spain.

“It is especially significant that protection was observed in participants with an eGFR > 60 mL/min/1.73 m² and across UACR categories, ie, including people without CKD at baseline, in whom it appeared to decrease the incidence of de novo CKD,” Dr. Ortiz told this news organization.

“This suggests a potential role in primary prevention of CKD in this population,” he said.

To further investigate this, he said, “It would have been extremely interesting to assess whether there is a potential role for primary prevention of CKD in people without baseline CKD by assessing subgroup results for the no-CKD, low-risk KDIGO [Kidney Disease: Improving Global Outcomes] category [of patients].”

SELECT was funded by Novo Nordisk. Dr. Colhoun has reported consulting, research, and/or other relationships with Novo Nordisk, Bayer, Sanofi, Roche, and IQVIA. Dr. Ortiz has reported being a member of the European Renal Association council and Madrid Society of Nephrology (SOMANE), which developed a document in 2022 on the treatment of diabetic kidney disease sponsored by Novo Nordisk. He also reported collaborating with companies developing drugs for kidney disease.

A version of this article first appeared on Medscape.com.

STOCKHOLM — Improvements in kidney function outcomes observed with glucagon-like peptide-1 (GLP-1) receptor agonists in patients with type 2 diabetes extend to patients who are overweight or obese but don›t yet have type 2 diabetes, new research shows.

“These data are important because they are the first data to suggest a kidney benefit of semaglutide in this patient population in the absence of diabetes,” lead author Helen M. Colhoun, MD, of the Institute of Genetics and Cancer, University of Edinburgh, Scotland, United Kingdom, told this news organization.

“This is a population at high risk of chronic kidney disease with an increased need for kidney protection,” she said.

The late-breaking study was presented this week at the 61st European Renal Association (ERA) Congress 2024 and simultaneously published in Nature Medicine.
 

SELECT Trial Patients Without Diabetes

The findings are from a secondary analysis of the randomized SELECT (Semaglutide Effects on Heart Disease and Stroke in Patients With Overweight or Obesity) trial, which evaluated cardiovascular outcomes of semaglutide treatment among 17,604 adults with preexisting cardiovascular disease who were overweight or obese — but did not have diabetes.

For its primary endpoint, the trial showed semaglutide was associated with a 20% reduction in major adverse cardiovascular events compared with placebo.

With obesity also associated with a significantly increased risk of chronic kidney disease — and the headline-making FLOW trial, also presented at the congress, showing key benefits of semaglutide in improving kidney function in people with CKD and type 2 diabetes the secondary analysis of SELECT was conducted to investigate whether those kidney benefits extended to people without type 2 diabetes.

Patients were randomized 1:1 to once-weekly subcutaneous semaglutide at a dose of 2.4 mg or placebo. Baseline patient characteristics were well-balanced, including kidney function and albuminuria status.

The primary endpoint for the analysis was a nephropathy composite of time from randomization to the first occurrence of death from kidney causes; initiation of chronic kidney replacement therapy; onset of persistent estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m²; persistent ≥ 50% reduction in eGFR compared with baseline; or onset of persistent macroalbuminuria.

With a median follow-up of 182 weeks, the results showed that the semaglutide group was significantly less likely to develop the primary composite endpoint compared with the placebo group (1.8% vs 2.2%; hazard ratio [HR], 0.78; P = .02).

A significantly reduced decline in eGFR in the semaglutide group was observed at a prespecified 104-week time point, with a treatment effect of 0.75 mL/min/1.73 m² (P < .001), and the effect was more pronounced among participants with baseline eGFR < 60 mL/min/1.73 m² (P < .001). 

Furthermore, those in the semaglutide group had a significantly lower proportionate increase in urinary albumin-to-creatinine ratio (UACR) compared with placebo (–10.7%; P < .001) at the prespecified 104 weeks, with a net treatment benefit of –27.2% and –31.4% among those with randomization to UACR 30 to < 300 mg/g and 2300 mg/g, respectively.

Improvements varied according to baseline UACR status and were more pronounced among those with macroalbuminuria, at –8.1% for those with normoalbuminuria (n = 14,848), –27% for microalbuminuria (n = 1968), and –31% for macroalbuminuria (n = 325).

There were no reports of acute kidney injury associated with semaglutide, regardless of baseline eGFR. 

“We were hopeful that there would be similar benefits as those observed in the diabetes studies, but there are differences in kidney disease among those with and without type 2 diabetes, so we weren’t sure,” Dr. Colhoun told this news organization.
 

Benefits the Result of Weight Loss or Something Else?

Considering the beneficial effects of semaglutide on weight loss, underscored in an analysis also published this month that showed a mean 10.2% reduction in weight sustained for up to 4  years, a key question is whether the kidney benefits are a direct result of weight loss — or the drug mechanism or something else.

But Dr. Colhoun said the role of weight loss in terms of the kidney benefits is still uncertain, particularly considering the various other factors, including cardiometabolic improvements, which could also have an effect.

“It’s a very difficult question to answer,” she said. “We did do a mediation exploratory analysis suggesting a substantial part of the effect might be due to the weight change, but it’s difficult to demonstrate that because you have weight change going on in the placebo arm as well, but for different reasons,” she said.

“So, I would say the data suggest there is some component of this that is attributable to weight, but we certainly can’t attribute all of the [effects] to weight change.”

Small studies involving animals have shown a direct effect of semaglutide on kidney hemodynamics “but they’re small and not definitive,” Dr. Colhoun added.

And although weight loss achieved through other measures such as lifestyle changes show a small benefit on eGFR, “interestingly, those studies showed no effect at all on albuminuria, whereas we see a really substantial effect on albuminuria with semaglutide,” Dr. Colhoun said.

Studies of weight loss through bariatric surgery have shown kidney benefits; however, those were in the context of type 2 diabetes, unlike the current analysis.

In terms of whether the benefits may extend to tirzepatide, the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist, increasingly used in weight loss, results from another secondary analysis also show encouraging kidney benefits in people with type 2 diabetes, and there is ongoing research in patients with type 2 diabetes and those with obesity without diabetes, Dr. Colhoun noted.
 

Primary Prevention of CKD?

Limitations of the current analysis include that only about a fifth of participants in SELECT had an eGFR < 60  mL/min/1.73 m² or UACR ≥ 30 mg/g at baseline, suggesting a relatively low proportion of participants with kidney disease. 

Importantly, however, the kidney benefits observed in patients who are at such high risk of kidney disease but do not yet have diabetes or CKD, is encouraging, said Alberto Ortiz, MD, PhD, commenting on the study. Dr. Ortiz is chief of nephrology and the Hypertension Renal Unit, Health Research Institute of the Jiménez Díaz Foundation, Madrid, Spain.

“It is especially significant that protection was observed in participants with an eGFR > 60 mL/min/1.73 m² and across UACR categories, ie, including people without CKD at baseline, in whom it appeared to decrease the incidence of de novo CKD,” Dr. Ortiz told this news organization.

“This suggests a potential role in primary prevention of CKD in this population,” he said.

To further investigate this, he said, “It would have been extremely interesting to assess whether there is a potential role for primary prevention of CKD in people without baseline CKD by assessing subgroup results for the no-CKD, low-risk KDIGO [Kidney Disease: Improving Global Outcomes] category [of patients].”

SELECT was funded by Novo Nordisk. Dr. Colhoun has reported consulting, research, and/or other relationships with Novo Nordisk, Bayer, Sanofi, Roche, and IQVIA. Dr. Ortiz has reported being a member of the European Renal Association council and Madrid Society of Nephrology (SOMANE), which developed a document in 2022 on the treatment of diabetic kidney disease sponsored by Novo Nordisk. He also reported collaborating with companies developing drugs for kidney disease.

A version of this article first appeared on Medscape.com.

STOCKHOLM — Improvements in kidney function outcomes observed with glucagon-like peptide-1 (GLP-1) receptor agonists in patients with type 2 diabetes extend to patients who are overweight or obese but don›t yet have type 2 diabetes, new research shows.

“These data are important because they are the first data to suggest a kidney benefit of semaglutide in this patient population in the absence of diabetes,” lead author Helen M. Colhoun, MD, of the Institute of Genetics and Cancer, University of Edinburgh, Scotland, United Kingdom, told this news organization.

“This is a population at high risk of chronic kidney disease with an increased need for kidney protection,” she said.

The late-breaking study was presented this week at the 61st European Renal Association (ERA) Congress 2024 and simultaneously published in Nature Medicine.
 

SELECT Trial Patients Without Diabetes

The findings are from a secondary analysis of the randomized SELECT (Semaglutide Effects on Heart Disease and Stroke in Patients With Overweight or Obesity) trial, which evaluated cardiovascular outcomes of semaglutide treatment among 17,604 adults with preexisting cardiovascular disease who were overweight or obese — but did not have diabetes.

For its primary endpoint, the trial showed semaglutide was associated with a 20% reduction in major adverse cardiovascular events compared with placebo.

With obesity also associated with a significantly increased risk of chronic kidney disease — and the headline-making FLOW trial, also presented at the congress, showing key benefits of semaglutide in improving kidney function in people with CKD and type 2 diabetes the secondary analysis of SELECT was conducted to investigate whether those kidney benefits extended to people without type 2 diabetes.

Patients were randomized 1:1 to once-weekly subcutaneous semaglutide at a dose of 2.4 mg or placebo. Baseline patient characteristics were well-balanced, including kidney function and albuminuria status.

The primary endpoint for the analysis was a nephropathy composite of time from randomization to the first occurrence of death from kidney causes; initiation of chronic kidney replacement therapy; onset of persistent estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m²; persistent ≥ 50% reduction in eGFR compared with baseline; or onset of persistent macroalbuminuria.

With a median follow-up of 182 weeks, the results showed that the semaglutide group was significantly less likely to develop the primary composite endpoint compared with the placebo group (1.8% vs 2.2%; hazard ratio [HR], 0.78; P = .02).

A significantly reduced decline in eGFR in the semaglutide group was observed at a prespecified 104-week time point, with a treatment effect of 0.75 mL/min/1.73 m² (P < .001), and the effect was more pronounced among participants with baseline eGFR < 60 mL/min/1.73 m² (P < .001). 

Furthermore, those in the semaglutide group had a significantly lower proportionate increase in urinary albumin-to-creatinine ratio (UACR) compared with placebo (–10.7%; P < .001) at the prespecified 104 weeks, with a net treatment benefit of –27.2% and –31.4% among those with randomization to UACR 30 to < 300 mg/g and 2300 mg/g, respectively.

Improvements varied according to baseline UACR status and were more pronounced among those with macroalbuminuria, at –8.1% for those with normoalbuminuria (n = 14,848), –27% for microalbuminuria (n = 1968), and –31% for macroalbuminuria (n = 325).

There were no reports of acute kidney injury associated with semaglutide, regardless of baseline eGFR. 

“We were hopeful that there would be similar benefits as those observed in the diabetes studies, but there are differences in kidney disease among those with and without type 2 diabetes, so we weren’t sure,” Dr. Colhoun told this news organization.
 

Benefits the Result of Weight Loss or Something Else?

Considering the beneficial effects of semaglutide on weight loss, underscored in an analysis also published this month that showed a mean 10.2% reduction in weight sustained for up to 4  years, a key question is whether the kidney benefits are a direct result of weight loss — or the drug mechanism or something else.

But Dr. Colhoun said the role of weight loss in terms of the kidney benefits is still uncertain, particularly considering the various other factors, including cardiometabolic improvements, which could also have an effect.

“It’s a very difficult question to answer,” she said. “We did do a mediation exploratory analysis suggesting a substantial part of the effect might be due to the weight change, but it’s difficult to demonstrate that because you have weight change going on in the placebo arm as well, but for different reasons,” she said.

“So, I would say the data suggest there is some component of this that is attributable to weight, but we certainly can’t attribute all of the [effects] to weight change.”

Small studies involving animals have shown a direct effect of semaglutide on kidney hemodynamics “but they’re small and not definitive,” Dr. Colhoun added.

And although weight loss achieved through other measures such as lifestyle changes show a small benefit on eGFR, “interestingly, those studies showed no effect at all on albuminuria, whereas we see a really substantial effect on albuminuria with semaglutide,” Dr. Colhoun said.

Studies of weight loss through bariatric surgery have shown kidney benefits; however, those were in the context of type 2 diabetes, unlike the current analysis.

In terms of whether the benefits may extend to tirzepatide, the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonist, increasingly used in weight loss, results from another secondary analysis also show encouraging kidney benefits in people with type 2 diabetes, and there is ongoing research in patients with type 2 diabetes and those with obesity without diabetes, Dr. Colhoun noted.
 

Primary Prevention of CKD?

Limitations of the current analysis include that only about a fifth of participants in SELECT had an eGFR < 60  mL/min/1.73 m² or UACR ≥ 30 mg/g at baseline, suggesting a relatively low proportion of participants with kidney disease. 

Importantly, however, the kidney benefits observed in patients who are at such high risk of kidney disease but do not yet have diabetes or CKD, is encouraging, said Alberto Ortiz, MD, PhD, commenting on the study. Dr. Ortiz is chief of nephrology and the Hypertension Renal Unit, Health Research Institute of the Jiménez Díaz Foundation, Madrid, Spain.

“It is especially significant that protection was observed in participants with an eGFR > 60 mL/min/1.73 m² and across UACR categories, ie, including people without CKD at baseline, in whom it appeared to decrease the incidence of de novo CKD,” Dr. Ortiz told this news organization.

“This suggests a potential role in primary prevention of CKD in this population,” he said.

To further investigate this, he said, “It would have been extremely interesting to assess whether there is a potential role for primary prevention of CKD in people without baseline CKD by assessing subgroup results for the no-CKD, low-risk KDIGO [Kidney Disease: Improving Global Outcomes] category [of patients].”

SELECT was funded by Novo Nordisk. Dr. Colhoun has reported consulting, research, and/or other relationships with Novo Nordisk, Bayer, Sanofi, Roche, and IQVIA. Dr. Ortiz has reported being a member of the European Renal Association council and Madrid Society of Nephrology (SOMANE), which developed a document in 2022 on the treatment of diabetic kidney disease sponsored by Novo Nordisk. He also reported collaborating with companies developing drugs for kidney disease.

A version of this article first appeared on Medscape.com.

Presentation

A 24-year-old man with no significant past medical history presents to urgent care with a 1-week history of sudden-onset dark urine, leg swelling, and unusually high blood pressure readings, with recent values around 160/100 mm Hg. Physical examination reveals pitting edema up to the mid-shins and mild periorbital edema, with an elevated blood pressure of 158/98 mm Hg. Past medical history was significant for frequent upper respiratory tract infections over the past year. Laboratory findings include hematuria, proteinuria, and a raised serum creatinine level at 1.8 mg/dL, indicating a reduced estimated glomerular filtration rate (eGFR) of 45 mL/min/1.73 m². Other tests such as a complete blood count and comprehensive metabolic panel (except for creatinine and albumin) are within normal limits. Given these findings, the patient is referred to nephrology for further evaluation to determine the underlying cause of his renal symptoms.

Differential Diagnosis

A glomerular disease can be assumed to be present if the patient manifests glomerular hematuria, glomerular proteinuria, or both, such as in this patient.

Glomerulonephritis occurs due to inflammation in the glomeruli, which leads to blood in urine, variable degrees of protein in urine (sometimes in the nephrotic range), and white blood cells in urine without any urinary tract infection. Patients may also experience hypertension and kidney function impairment. Diagnoses to consider include:

• Postinfectious glomerulonephritis
• Crescentic glomerulonephritis
• Diffuse proliferative glomerulonephritis
• Glomerulonephritis associated with nonstreptococcal infection
• Membranoproliferative glomerulonephritis
• Membranous glomerulonephritis
• Poststreptococcal glomerulonephritis
• Rapidly Progressive glomerulonephritis

All patients presenting with proteinuria and hematuria should undergo a thorough evaluation for glomerular disease, which generally involves laboratory testing and, in most patients, a kidney biopsy to obtain a definitive diagnosis.
 

Diagnosis

This patient underwent a renal biopsy, which showed C3-dominant deposition by immunofluorescence; electron microscopy (EM) showed discontinuous, ill-defined intramembranous deposits; and mass spectrometry showed terminal complement components in C3 deposits. The patient was diagnosed with C3 glomerulonephritis (C3G).

The diagnosis of C3G is established by kidney biopsy demonstrating the characteristic findings on immunofluorescence microscopy or EM in a patient with suspected glomerulonephritis. In patients with biopsy-confirmed C3G, additional testing should be performed to help identify the underlying etiology of the glomerulopathy to help determine therapy.

For all patients diagnosed with C3G, especially those who are older than 50 years, it is important to rule out monoclonal gammopathy which can be done through various tests such as serum protein electrophoresis and immunofixation, serum free light chains, and urine protein electrophoresis and immunofixation. The presence of a paraprotein, including a monoclonal light chain, can activate the alternative complement cascade and may be responsible for the condition.

Expert opinion recommends a comprehensive complement evaluation for all C3 glomerulopathy patients, including overall complement activity assessment, serum levels measurement of complement proteins and their split products, and autoantibodies screening.

Complement evaluation may include:

• Serum C3 and C4
• Soluble C5b-9 (soluble membrane attack complex)
• Serum factor H
• Serum factor B, factor I, and membrane cofactor protein (MCP; CD46)

All patients with C3G should also undergo screening for autoantibodies:

• C3 nephritic factor (C3NeF)
• C5 nephritic factor (C5NeF)
• C4 nephritic factor (C4NeF)
• Other autoantibodies against factor H, factor B, and/or C3b

It is recommended that genetic testing be considered for patients with C3 glomerulopathy to screen for complement genes including C3, CFB, CFH, CFHR5, and CFI and copy number variations and rearrangements of the CFH-CFHR gene cluster. The value of genetic testing in the clinical setting is still being defined; however, it has been observed that patients with mutations in complement genes generally respond less favorably to mycophenolate mofetil (MMF) compared with those who are positive for nephritic factors.
 

Management

The patient was managed with an angiotensin-converting enzyme (ACE) inhibitor to treat proteinuria and hypertension and MMF for immunosuppression. Enrollment in a clinical trial of an investigational complement inhibitor was discussed with the patient.

Currently, there are no therapeutic agents specifically designed to target the underlying complement dysregulation that occurs in individuals with C3G, and an optimal treatment for C3 glomerulopathy has not been established.

Various nonspecific therapies have been used to treat C3G, including plasmapheresis, steroids, rituximab, cyclophosphamide, and MMF and have shown positive results. For patients with C3G who have a known genetic variant (eg, CFH mutation) or who have acute kidney injury, plasmapheresis and plasma exchange may be helpful. Using these agents judiciously and in conjunction with optimal blood pressure control is important for maximum benefit in treating C3G. When someone with end-stage renal disease (ESRD) caused by C3G chooses to have a kidney transplant, it is important to know that C3G is likely to return in almost all cases and is the leading cause of transplant failure in 50%-90% of recipients.
 

Prognosis

The prognosis of C3G varies and is affected by various clinical and histological factors. While some patients may have consistently low levels of protein in their urine and maintain stable kidney function over time, others may experience severe nephrotic syndrome or rapidly progressive glomerulonephritis, which often leads to a poor prognosis.

Progression to ESRD is a major complication of C3G, with approximately 70% of affected children and 30%-50% of adults reaching this stage. In addition, disease recurrence is common after kidney transplantation, with about 50% of patients experiencing allograft loss within 10 years. Predictive factors for disease progression, although not robustly established, include initial eGFR at diagnosis, percentage of tubular atrophy, and extent of interstitial fibrosis in the cortical area as observed on kidney biopsies.
 

Clinical Takeaways

For patients exhibiting symptoms like proteinuria and hematuria indicative of glomerulonephritis, a comprehensive evaluation including laboratory tests and a kidney biopsy is essential to confirm a C3G diagnosis through characteristic findings on immunofluorescence microscopy or electron microscopy.

Additional tests to rule out associated conditions like monoclonal gammopathy and comprehensive complement evaluation are also recommended to understand the underlying etiology and guide therapy.

Though there are no treatments specifically targeting the underlying complement dysregulation unique to C3G, nonspecific therapies like ACE inhibitors, immunosuppressants (eg, MMF), and plasmapheresis are commonly used.

Some anticomplement therapies are available or under investigation, which might offer more targeted intervention options.

The prognosis for patients with C3G can vary widely and factors such as initial eGFR, the extent of tubular atrophy, and interstitial fibrosis are important predictors of disease progression.

Dr. Alper is an associate professor, Nephrology, Tulane University School of Medicine, New Orleans, Louisiana. He has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Presentation

A 24-year-old man with no significant past medical history presents to urgent care with a 1-week history of sudden-onset dark urine, leg swelling, and unusually high blood pressure readings, with recent values around 160/100 mm Hg. Physical examination reveals pitting edema up to the mid-shins and mild periorbital edema, with an elevated blood pressure of 158/98 mm Hg. Past medical history was significant for frequent upper respiratory tract infections over the past year. Laboratory findings include hematuria, proteinuria, and a raised serum creatinine level at 1.8 mg/dL, indicating a reduced estimated glomerular filtration rate (eGFR) of 45 mL/min/1.73 m². Other tests such as a complete blood count and comprehensive metabolic panel (except for creatinine and albumin) are within normal limits. Given these findings, the patient is referred to nephrology for further evaluation to determine the underlying cause of his renal symptoms.

Differential Diagnosis

A glomerular disease can be assumed to be present if the patient manifests glomerular hematuria, glomerular proteinuria, or both, such as in this patient.

Glomerulonephritis occurs due to inflammation in the glomeruli, which leads to blood in urine, variable degrees of protein in urine (sometimes in the nephrotic range), and white blood cells in urine without any urinary tract infection. Patients may also experience hypertension and kidney function impairment. Diagnoses to consider include:

• Postinfectious glomerulonephritis
• Crescentic glomerulonephritis
• Diffuse proliferative glomerulonephritis
• Glomerulonephritis associated with nonstreptococcal infection
• Membranoproliferative glomerulonephritis
• Membranous glomerulonephritis
• Poststreptococcal glomerulonephritis
• Rapidly Progressive glomerulonephritis

All patients presenting with proteinuria and hematuria should undergo a thorough evaluation for glomerular disease, which generally involves laboratory testing and, in most patients, a kidney biopsy to obtain a definitive diagnosis.
 

Diagnosis

This patient underwent a renal biopsy, which showed C3-dominant deposition by immunofluorescence; electron microscopy (EM) showed discontinuous, ill-defined intramembranous deposits; and mass spectrometry showed terminal complement components in C3 deposits. The patient was diagnosed with C3 glomerulonephritis (C3G).

The diagnosis of C3G is established by kidney biopsy demonstrating the characteristic findings on immunofluorescence microscopy or EM in a patient with suspected glomerulonephritis. In patients with biopsy-confirmed C3G, additional testing should be performed to help identify the underlying etiology of the glomerulopathy to help determine therapy.

For all patients diagnosed with C3G, especially those who are older than 50 years, it is important to rule out monoclonal gammopathy which can be done through various tests such as serum protein electrophoresis and immunofixation, serum free light chains, and urine protein electrophoresis and immunofixation. The presence of a paraprotein, including a monoclonal light chain, can activate the alternative complement cascade and may be responsible for the condition.

Expert opinion recommends a comprehensive complement evaluation for all C3 glomerulopathy patients, including overall complement activity assessment, serum levels measurement of complement proteins and their split products, and autoantibodies screening.

Complement evaluation may include:

• Serum C3 and C4
• Soluble C5b-9 (soluble membrane attack complex)
• Serum factor H
• Serum factor B, factor I, and membrane cofactor protein (MCP; CD46)

All patients with C3G should also undergo screening for autoantibodies:

• C3 nephritic factor (C3NeF)
• C5 nephritic factor (C5NeF)
• C4 nephritic factor (C4NeF)
• Other autoantibodies against factor H, factor B, and/or C3b

It is recommended that genetic testing be considered for patients with C3 glomerulopathy to screen for complement genes including C3, CFB, CFH, CFHR5, and CFI and copy number variations and rearrangements of the CFH-CFHR gene cluster. The value of genetic testing in the clinical setting is still being defined; however, it has been observed that patients with mutations in complement genes generally respond less favorably to mycophenolate mofetil (MMF) compared with those who are positive for nephritic factors.
 

Management

The patient was managed with an angiotensin-converting enzyme (ACE) inhibitor to treat proteinuria and hypertension and MMF for immunosuppression. Enrollment in a clinical trial of an investigational complement inhibitor was discussed with the patient.

Currently, there are no therapeutic agents specifically designed to target the underlying complement dysregulation that occurs in individuals with C3G, and an optimal treatment for C3 glomerulopathy has not been established.

Various nonspecific therapies have been used to treat C3G, including plasmapheresis, steroids, rituximab, cyclophosphamide, and MMF and have shown positive results. For patients with C3G who have a known genetic variant (eg, CFH mutation) or who have acute kidney injury, plasmapheresis and plasma exchange may be helpful. Using these agents judiciously and in conjunction with optimal blood pressure control is important for maximum benefit in treating C3G. When someone with end-stage renal disease (ESRD) caused by C3G chooses to have a kidney transplant, it is important to know that C3G is likely to return in almost all cases and is the leading cause of transplant failure in 50%-90% of recipients.
 

Prognosis

The prognosis of C3G varies and is affected by various clinical and histological factors. While some patients may have consistently low levels of protein in their urine and maintain stable kidney function over time, others may experience severe nephrotic syndrome or rapidly progressive glomerulonephritis, which often leads to a poor prognosis.

Progression to ESRD is a major complication of C3G, with approximately 70% of affected children and 30%-50% of adults reaching this stage. In addition, disease recurrence is common after kidney transplantation, with about 50% of patients experiencing allograft loss within 10 years. Predictive factors for disease progression, although not robustly established, include initial eGFR at diagnosis, percentage of tubular atrophy, and extent of interstitial fibrosis in the cortical area as observed on kidney biopsies.
 

Clinical Takeaways

For patients exhibiting symptoms like proteinuria and hematuria indicative of glomerulonephritis, a comprehensive evaluation including laboratory tests and a kidney biopsy is essential to confirm a C3G diagnosis through characteristic findings on immunofluorescence microscopy or electron microscopy.

Additional tests to rule out associated conditions like monoclonal gammopathy and comprehensive complement evaluation are also recommended to understand the underlying etiology and guide therapy.

Though there are no treatments specifically targeting the underlying complement dysregulation unique to C3G, nonspecific therapies like ACE inhibitors, immunosuppressants (eg, MMF), and plasmapheresis are commonly used.

Some anticomplement therapies are available or under investigation, which might offer more targeted intervention options.

The prognosis for patients with C3G can vary widely and factors such as initial eGFR, the extent of tubular atrophy, and interstitial fibrosis are important predictors of disease progression.

Dr. Alper is an associate professor, Nephrology, Tulane University School of Medicine, New Orleans, Louisiana. He has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Presentation

A 24-year-old man with no significant past medical history presents to urgent care with a 1-week history of sudden-onset dark urine, leg swelling, and unusually high blood pressure readings, with recent values around 160/100 mm Hg. Physical examination reveals pitting edema up to the mid-shins and mild periorbital edema, with an elevated blood pressure of 158/98 mm Hg. Past medical history was significant for frequent upper respiratory tract infections over the past year. Laboratory findings include hematuria, proteinuria, and a raised serum creatinine level at 1.8 mg/dL, indicating a reduced estimated glomerular filtration rate (eGFR) of 45 mL/min/1.73 m². Other tests such as a complete blood count and comprehensive metabolic panel (except for creatinine and albumin) are within normal limits. Given these findings, the patient is referred to nephrology for further evaluation to determine the underlying cause of his renal symptoms.

Differential Diagnosis

A glomerular disease can be assumed to be present if the patient manifests glomerular hematuria, glomerular proteinuria, or both, such as in this patient.

Glomerulonephritis occurs due to inflammation in the glomeruli, which leads to blood in urine, variable degrees of protein in urine (sometimes in the nephrotic range), and white blood cells in urine without any urinary tract infection. Patients may also experience hypertension and kidney function impairment. Diagnoses to consider include:

• Postinfectious glomerulonephritis
• Crescentic glomerulonephritis
• Diffuse proliferative glomerulonephritis
• Glomerulonephritis associated with nonstreptococcal infection
• Membranoproliferative glomerulonephritis
• Membranous glomerulonephritis
• Poststreptococcal glomerulonephritis
• Rapidly Progressive glomerulonephritis

All patients presenting with proteinuria and hematuria should undergo a thorough evaluation for glomerular disease, which generally involves laboratory testing and, in most patients, a kidney biopsy to obtain a definitive diagnosis.
 

Diagnosis

This patient underwent a renal biopsy, which showed C3-dominant deposition by immunofluorescence; electron microscopy (EM) showed discontinuous, ill-defined intramembranous deposits; and mass spectrometry showed terminal complement components in C3 deposits. The patient was diagnosed with C3 glomerulonephritis (C3G).

The diagnosis of C3G is established by kidney biopsy demonstrating the characteristic findings on immunofluorescence microscopy or EM in a patient with suspected glomerulonephritis. In patients with biopsy-confirmed C3G, additional testing should be performed to help identify the underlying etiology of the glomerulopathy to help determine therapy.

For all patients diagnosed with C3G, especially those who are older than 50 years, it is important to rule out monoclonal gammopathy which can be done through various tests such as serum protein electrophoresis and immunofixation, serum free light chains, and urine protein electrophoresis and immunofixation. The presence of a paraprotein, including a monoclonal light chain, can activate the alternative complement cascade and may be responsible for the condition.

Expert opinion recommends a comprehensive complement evaluation for all C3 glomerulopathy patients, including overall complement activity assessment, serum levels measurement of complement proteins and their split products, and autoantibodies screening.

Complement evaluation may include:

• Serum C3 and C4
• Soluble C5b-9 (soluble membrane attack complex)
• Serum factor H
• Serum factor B, factor I, and membrane cofactor protein (MCP; CD46)

All patients with C3G should also undergo screening for autoantibodies:

• C3 nephritic factor (C3NeF)
• C5 nephritic factor (C5NeF)
• C4 nephritic factor (C4NeF)
• Other autoantibodies against factor H, factor B, and/or C3b

It is recommended that genetic testing be considered for patients with C3 glomerulopathy to screen for complement genes including C3, CFB, CFH, CFHR5, and CFI and copy number variations and rearrangements of the CFH-CFHR gene cluster. The value of genetic testing in the clinical setting is still being defined; however, it has been observed that patients with mutations in complement genes generally respond less favorably to mycophenolate mofetil (MMF) compared with those who are positive for nephritic factors.
 

Management

The patient was managed with an angiotensin-converting enzyme (ACE) inhibitor to treat proteinuria and hypertension and MMF for immunosuppression. Enrollment in a clinical trial of an investigational complement inhibitor was discussed with the patient.

Currently, there are no therapeutic agents specifically designed to target the underlying complement dysregulation that occurs in individuals with C3G, and an optimal treatment for C3 glomerulopathy has not been established.

Various nonspecific therapies have been used to treat C3G, including plasmapheresis, steroids, rituximab, cyclophosphamide, and MMF and have shown positive results. For patients with C3G who have a known genetic variant (eg, CFH mutation) or who have acute kidney injury, plasmapheresis and plasma exchange may be helpful. Using these agents judiciously and in conjunction with optimal blood pressure control is important for maximum benefit in treating C3G. When someone with end-stage renal disease (ESRD) caused by C3G chooses to have a kidney transplant, it is important to know that C3G is likely to return in almost all cases and is the leading cause of transplant failure in 50%-90% of recipients.
 

Prognosis

The prognosis of C3G varies and is affected by various clinical and histological factors. While some patients may have consistently low levels of protein in their urine and maintain stable kidney function over time, others may experience severe nephrotic syndrome or rapidly progressive glomerulonephritis, which often leads to a poor prognosis.

Progression to ESRD is a major complication of C3G, with approximately 70% of affected children and 30%-50% of adults reaching this stage. In addition, disease recurrence is common after kidney transplantation, with about 50% of patients experiencing allograft loss within 10 years. Predictive factors for disease progression, although not robustly established, include initial eGFR at diagnosis, percentage of tubular atrophy, and extent of interstitial fibrosis in the cortical area as observed on kidney biopsies.
 

Clinical Takeaways

For patients exhibiting symptoms like proteinuria and hematuria indicative of glomerulonephritis, a comprehensive evaluation including laboratory tests and a kidney biopsy is essential to confirm a C3G diagnosis through characteristic findings on immunofluorescence microscopy or electron microscopy.

Additional tests to rule out associated conditions like monoclonal gammopathy and comprehensive complement evaluation are also recommended to understand the underlying etiology and guide therapy.

Though there are no treatments specifically targeting the underlying complement dysregulation unique to C3G, nonspecific therapies like ACE inhibitors, immunosuppressants (eg, MMF), and plasmapheresis are commonly used.

Some anticomplement therapies are available or under investigation, which might offer more targeted intervention options.

The prognosis for patients with C3G can vary widely and factors such as initial eGFR, the extent of tubular atrophy, and interstitial fibrosis are important predictors of disease progression.

Dr. Alper is an associate professor, Nephrology, Tulane University School of Medicine, New Orleans, Louisiana. He has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

TOPLINE:

Treatment with biologic disease-modifying antirheumatic drugs (bDMARDs), particularly tocilizumab, can suppress inflammation and preserve renal function in a majority of patients with chronic inflammatory disorders who develop serum amyloid alpha (SAA) amyloidosis.

METHODOLOGY:

• AA amyloidosis, characterized by the misfolding of the SAA protein, is observed in patients with inflammatory diseases and can lead to progressive organ damage, including chronic kidney disease, malabsorption with cachexia, and cardiac failure.
• This monocentric, retrospective analysis assessed the effect of bDMARD therapy on inflammatory biomarker levels and renal outcomes in 83 patients with AA amyloidosis who were followed for a mean period of 4.82 years.
• The patients were stratified into three major subgroups depending on the cause of AA amyloidosis:
• Chronic inflammatory diseases (cid + AA; n = 34) such as rheumatoid arthritis, Crohn’s disease, and chronic infections
• Autoinflammatory syndromes (auto + AA; n = 24) such as familial Mediterranean fever (FMF) and cryopyrin-associated periodic syndrome (CAPS)
• Idiopathic AA (idio + AA; n = 25), wherein the primary disease could not be identified
• Tocilizumab was the most commonly used bDMARD in patients with cid + AA and idio + AA amyloidosis, and interleukin-1 inhibitors were prescribed to patients with auto + AA amyloidosis because tocilizumab has not been approved yet for FMF or CAPS treatment.
• All patients with AA amyloidosis had renal involvement, as confirmed by kidney biopsy.

TAKEAWAY:

• After bDMARD therapy, C-reactive protein levels reduced significantly from baseline to the last-documented visit in all subgroups, while SAA levels declined in the subgroups cid + AA and idio + AA and proteinuria dropped in the subgroups auto + AA and idio + AA.
• bDMARDs prevented progression to end-stage renal disease (ESRD) in 75% of the patients in the overall cohort, with progression to ESRD being prevented in 60% of patients with cid + AA, 88% of patients with auto + AA, and 81% of patients with idio + AA.
• Tocilizumab was more effective than other bDMARDs in preventing renal progression to ESRD (P = .0006), with a similar pattern observed for the subgroups cid + AA (P = .0126) and idio + AA (P = .0259).
• None of the patients receiving tocilizumab died during the nearly 5-year follow-up period.

IN PRACTICE:

“The data suggest preferential use of IL [interleukin]-1 inhibitors and tocilizumab for clinical use in the treatment of AA amyloidosis depending on the respective underlying diseases,” the authors wrote.

SOURCE:

This study, led by Peter Kvacskay, MD, of Heidelberg University Hospital, Heidelberg, Germany, was published online on April 23 in Annals of the Rheumatic Diseases.

LIMITATIONS:

Authors acknowledged the retrospective nature of the analysis and missing data of single patients during the long-term follow-up as major limitations. Furthermore, the cid + AA subgroup was heterogeneous in terms of the pathophysiology of their underlying primary disease.

DISCLOSURES:

This study did not report any source of funding. The authors declared no conflicts of interest.

A version of this article appeared on Medscape.com.

TOPLINE:

Treatment with biologic disease-modifying antirheumatic drugs (bDMARDs), particularly tocilizumab, can suppress inflammation and preserve renal function in a majority of patients with chronic inflammatory disorders who develop serum amyloid alpha (SAA) amyloidosis.

METHODOLOGY:

• AA amyloidosis, characterized by the misfolding of the SAA protein, is observed in patients with inflammatory diseases and can lead to progressive organ damage, including chronic kidney disease, malabsorption with cachexia, and cardiac failure.
• This monocentric, retrospective analysis assessed the effect of bDMARD therapy on inflammatory biomarker levels and renal outcomes in 83 patients with AA amyloidosis who were followed for a mean period of 4.82 years.
• The patients were stratified into three major subgroups depending on the cause of AA amyloidosis:
• Chronic inflammatory diseases (cid + AA; n = 34) such as rheumatoid arthritis, Crohn’s disease, and chronic infections
• Autoinflammatory syndromes (auto + AA; n = 24) such as familial Mediterranean fever (FMF) and cryopyrin-associated periodic syndrome (CAPS)
• Idiopathic AA (idio + AA; n = 25), wherein the primary disease could not be identified
• Tocilizumab was the most commonly used bDMARD in patients with cid + AA and idio + AA amyloidosis, and interleukin-1 inhibitors were prescribed to patients with auto + AA amyloidosis because tocilizumab has not been approved yet for FMF or CAPS treatment.
• All patients with AA amyloidosis had renal involvement, as confirmed by kidney biopsy.

TAKEAWAY:

• After bDMARD therapy, C-reactive protein levels reduced significantly from baseline to the last-documented visit in all subgroups, while SAA levels declined in the subgroups cid + AA and idio + AA and proteinuria dropped in the subgroups auto + AA and idio + AA.
• bDMARDs prevented progression to end-stage renal disease (ESRD) in 75% of the patients in the overall cohort, with progression to ESRD being prevented in 60% of patients with cid + AA, 88% of patients with auto + AA, and 81% of patients with idio + AA.
• Tocilizumab was more effective than other bDMARDs in preventing renal progression to ESRD (P = .0006), with a similar pattern observed for the subgroups cid + AA (P = .0126) and idio + AA (P = .0259).
• None of the patients receiving tocilizumab died during the nearly 5-year follow-up period.

IN PRACTICE:

“The data suggest preferential use of IL [interleukin]-1 inhibitors and tocilizumab for clinical use in the treatment of AA amyloidosis depending on the respective underlying diseases,” the authors wrote.

SOURCE:

This study, led by Peter Kvacskay, MD, of Heidelberg University Hospital, Heidelberg, Germany, was published online on April 23 in Annals of the Rheumatic Diseases.

LIMITATIONS:

Authors acknowledged the retrospective nature of the analysis and missing data of single patients during the long-term follow-up as major limitations. Furthermore, the cid + AA subgroup was heterogeneous in terms of the pathophysiology of their underlying primary disease.

DISCLOSURES:

This study did not report any source of funding. The authors declared no conflicts of interest.

A version of this article appeared on Medscape.com.

TOPLINE:

Treatment with biologic disease-modifying antirheumatic drugs (bDMARDs), particularly tocilizumab, can suppress inflammation and preserve renal function in a majority of patients with chronic inflammatory disorders who develop serum amyloid alpha (SAA) amyloidosis.

METHODOLOGY:

• AA amyloidosis, characterized by the misfolding of the SAA protein, is observed in patients with inflammatory diseases and can lead to progressive organ damage, including chronic kidney disease, malabsorption with cachexia, and cardiac failure.
• This monocentric, retrospective analysis assessed the effect of bDMARD therapy on inflammatory biomarker levels and renal outcomes in 83 patients with AA amyloidosis who were followed for a mean period of 4.82 years.
• The patients were stratified into three major subgroups depending on the cause of AA amyloidosis:
• Chronic inflammatory diseases (cid + AA; n = 34) such as rheumatoid arthritis, Crohn’s disease, and chronic infections
• Autoinflammatory syndromes (auto + AA; n = 24) such as familial Mediterranean fever (FMF) and cryopyrin-associated periodic syndrome (CAPS)
• Idiopathic AA (idio + AA; n = 25), wherein the primary disease could not be identified
• Tocilizumab was the most commonly used bDMARD in patients with cid + AA and idio + AA amyloidosis, and interleukin-1 inhibitors were prescribed to patients with auto + AA amyloidosis because tocilizumab has not been approved yet for FMF or CAPS treatment.
• All patients with AA amyloidosis had renal involvement, as confirmed by kidney biopsy.

TAKEAWAY:

• After bDMARD therapy, C-reactive protein levels reduced significantly from baseline to the last-documented visit in all subgroups, while SAA levels declined in the subgroups cid + AA and idio + AA and proteinuria dropped in the subgroups auto + AA and idio + AA.
• bDMARDs prevented progression to end-stage renal disease (ESRD) in 75% of the patients in the overall cohort, with progression to ESRD being prevented in 60% of patients with cid + AA, 88% of patients with auto + AA, and 81% of patients with idio + AA.
• Tocilizumab was more effective than other bDMARDs in preventing renal progression to ESRD (P = .0006), with a similar pattern observed for the subgroups cid + AA (P = .0126) and idio + AA (P = .0259).
• None of the patients receiving tocilizumab died during the nearly 5-year follow-up period.

IN PRACTICE:

“The data suggest preferential use of IL [interleukin]-1 inhibitors and tocilizumab for clinical use in the treatment of AA amyloidosis depending on the respective underlying diseases,” the authors wrote.

SOURCE:

This study, led by Peter Kvacskay, MD, of Heidelberg University Hospital, Heidelberg, Germany, was published online on April 23 in Annals of the Rheumatic Diseases.

LIMITATIONS:

Authors acknowledged the retrospective nature of the analysis and missing data of single patients during the long-term follow-up as major limitations. Furthermore, the cid + AA subgroup was heterogeneous in terms of the pathophysiology of their underlying primary disease.

DISCLOSURES:

This study did not report any source of funding. The authors declared no conflicts of interest.

A version of this article appeared on Medscape.com.

A 59-year-old man presents with abdominal pain. He has a history of small bowel obstruction and diverticulitis. His medical history includes chronic kidney disease (CKD; baseline creatinine, 1.8 mg/dL), hypertension, type 2 diabetes, and depression. He had a colectomy 6 years ago for colon cancer.

He takes the following medications: Semaglutide (1 mg weekly), amlodipine (5 mg once daily), and escitalopram (10 mg once daily). On physical exam his blood pressure is 130/80 mm Hg, his pulse is 90, and his temperature is 37.2 degrees C. He has normal bowel sounds but guarding in the right lower quadrant.

Paauw_Doug_SEATTLE_2019_web.jpg

What imaging would you recommend?

A) CT without contrast

B) CT with contrast

C) MRI

D) Abdominal ultrasound

This patient has several potential causes for his abdominal pain that imaging may clarify. I think a contrast CT scan would be the most likely to provide helpful information. It is likely that if it were ordered, there may be hesitation by the radiologist to perform the scan with contrast because of the patient’s CKD.

Concern for contrast-induced kidney injury has limited diagnostic testing for many years. How strong is the evidence for contrast-induced kidney injury, and should we avoid testing that requires contrast in patients with CKD? McDonald and colleagues performed a meta-analysis with 13 studies meeting inclusion criteria, involving 25,950 patients.¹ They found no increased risk of acute kidney injury (AKI) in patients who received contrast medium compared with those who did not receive contrast; relative risk of AKI for those receiving contrast was 0.79 (confidence interval: 0.62-1.02). Importantly, there was no difference in AKI in patients with diabetes or CKD.

Ehmann et al. looked at renal outcomes in patients who received IV contrast when they presented to an emergency department with AKI.² They found that in patients with AKI, receiving contrast was not associated with persistent AKI at hospital discharge. Hinson and colleagues looked at patients arriving at the emergency department and needing imaging.³ They did a retrospective, cohort analysis of 17,934 patients who had CT with contrast, CT with no contrast, or no CT. Contrast administration was not associated with increased incidence of AKI (odds ratio, 0.96, CI: 0.85-1.08).

Aycock et al. did a meta-analysis of AKI after CT scanning, including 28 studies involving 107,335 patients.⁴ They found that compared with noncontrast CT, CT scanning with contrast was not associated with AKI (OR, 0.94, CI: 0.83-1.07). Elias and Aronson looked at the risk of AKI after contrast in patients receiving CT scans compared with those who received ventilation/perfusion scans to evaluate for pulmonary embolism.⁵ There were 44 AKI events (4.5%) in patients exposed to contrast media and 33 events (3.4%) in patients not exposed to contrast media (risk difference: 1.1%, 95% CI: -0.6% to 2.9%; OR, 1.39, CI: 0.86-2.26; P = .18).

Despite multiple studies showing no increased risk, there is still a concern that contrast can cause AKI.⁶ Animal models have shown iodinated contrast can have a deleterious effect on mitochondria and membrane function.⁶ Criticisms of the retrospective nature of many of the studies I have shared, and the lack of randomized, controlled trials are that there may be bias in these studies, as the highest-risk patients are the ones most likely not to receive contrast. In a joint guideline from the American College of Radiology and the National Kidney Foundation, this statement was made: “The risk of acute kidney injury developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated.”⁷ Their recommendation was to give contrast if needed in patients with glomerular filtration rates (GFRs) greater than 30.



Myth: Contrast-induced renal injury is a concern.

Clinical impact: For CT scanning, it is OK to give contrast when needed. A conservative cutoff for contrast use would be a GFR less than 30.
 

Dr. Paauw is professor of medicine in the Division of General Internal Medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at dpaauw@uw.edu.

References

1. McDonald JS et al. Radiology. 2013:267:119-128.

2. Ehmann MR et al. Intensive Care Med. 2023:49(2):205-215.

3. Hinson JS et al. Ann Emerg Med. 2017;69(5):577-586.

4. Aycock RD et al. Ann Emerg Med. 2018 Jan;71(1):44-53.

5. Elias A, Aronson D. Thromb Haemost. 2021 Jun;121(6):800-807.

6. Weisbord SD, du Cheryon D. Intensive Care Med. 2018;44(1):107-109.

7. Davenport MS et al. Radiology. 2020;294(3):660-668.

A 59-year-old man presents with abdominal pain. He has a history of small bowel obstruction and diverticulitis. His medical history includes chronic kidney disease (CKD; baseline creatinine, 1.8 mg/dL), hypertension, type 2 diabetes, and depression. He had a colectomy 6 years ago for colon cancer.

He takes the following medications: Semaglutide (1 mg weekly), amlodipine (5 mg once daily), and escitalopram (10 mg once daily). On physical exam his blood pressure is 130/80 mm Hg, his pulse is 90, and his temperature is 37.2 degrees C. He has normal bowel sounds but guarding in the right lower quadrant.

Paauw_Doug_SEATTLE_2019_web.jpg

What imaging would you recommend?

A) CT without contrast

B) CT with contrast

C) MRI

D) Abdominal ultrasound

This patient has several potential causes for his abdominal pain that imaging may clarify. I think a contrast CT scan would be the most likely to provide helpful information. It is likely that if it were ordered, there may be hesitation by the radiologist to perform the scan with contrast because of the patient’s CKD.

Concern for contrast-induced kidney injury has limited diagnostic testing for many years. How strong is the evidence for contrast-induced kidney injury, and should we avoid testing that requires contrast in patients with CKD? McDonald and colleagues performed a meta-analysis with 13 studies meeting inclusion criteria, involving 25,950 patients.¹ They found no increased risk of acute kidney injury (AKI) in patients who received contrast medium compared with those who did not receive contrast; relative risk of AKI for those receiving contrast was 0.79 (confidence interval: 0.62-1.02). Importantly, there was no difference in AKI in patients with diabetes or CKD.

Ehmann et al. looked at renal outcomes in patients who received IV contrast when they presented to an emergency department with AKI.² They found that in patients with AKI, receiving contrast was not associated with persistent AKI at hospital discharge. Hinson and colleagues looked at patients arriving at the emergency department and needing imaging.³ They did a retrospective, cohort analysis of 17,934 patients who had CT with contrast, CT with no contrast, or no CT. Contrast administration was not associated with increased incidence of AKI (odds ratio, 0.96, CI: 0.85-1.08).

Aycock et al. did a meta-analysis of AKI after CT scanning, including 28 studies involving 107,335 patients.⁴ They found that compared with noncontrast CT, CT scanning with contrast was not associated with AKI (OR, 0.94, CI: 0.83-1.07). Elias and Aronson looked at the risk of AKI after contrast in patients receiving CT scans compared with those who received ventilation/perfusion scans to evaluate for pulmonary embolism.⁵ There were 44 AKI events (4.5%) in patients exposed to contrast media and 33 events (3.4%) in patients not exposed to contrast media (risk difference: 1.1%, 95% CI: -0.6% to 2.9%; OR, 1.39, CI: 0.86-2.26; P = .18).

Despite multiple studies showing no increased risk, there is still a concern that contrast can cause AKI.⁶ Animal models have shown iodinated contrast can have a deleterious effect on mitochondria and membrane function.⁶ Criticisms of the retrospective nature of many of the studies I have shared, and the lack of randomized, controlled trials are that there may be bias in these studies, as the highest-risk patients are the ones most likely not to receive contrast. In a joint guideline from the American College of Radiology and the National Kidney Foundation, this statement was made: “The risk of acute kidney injury developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated.”⁷ Their recommendation was to give contrast if needed in patients with glomerular filtration rates (GFRs) greater than 30.



Myth: Contrast-induced renal injury is a concern.

Clinical impact: For CT scanning, it is OK to give contrast when needed. A conservative cutoff for contrast use would be a GFR less than 30.
 

Dr. Paauw is professor of medicine in the Division of General Internal Medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at dpaauw@uw.edu.

References

1. McDonald JS et al. Radiology. 2013:267:119-128.

2. Ehmann MR et al. Intensive Care Med. 2023:49(2):205-215.

3. Hinson JS et al. Ann Emerg Med. 2017;69(5):577-586.

4. Aycock RD et al. Ann Emerg Med. 2018 Jan;71(1):44-53.

5. Elias A, Aronson D. Thromb Haemost. 2021 Jun;121(6):800-807.

6. Weisbord SD, du Cheryon D. Intensive Care Med. 2018;44(1):107-109.

7. Davenport MS et al. Radiology. 2020;294(3):660-668.

A 59-year-old man presents with abdominal pain. He has a history of small bowel obstruction and diverticulitis. His medical history includes chronic kidney disease (CKD; baseline creatinine, 1.8 mg/dL), hypertension, type 2 diabetes, and depression. He had a colectomy 6 years ago for colon cancer.

He takes the following medications: Semaglutide (1 mg weekly), amlodipine (5 mg once daily), and escitalopram (10 mg once daily). On physical exam his blood pressure is 130/80 mm Hg, his pulse is 90, and his temperature is 37.2 degrees C. He has normal bowel sounds but guarding in the right lower quadrant.

Paauw_Doug_SEATTLE_2019_web.jpg

What imaging would you recommend?

A) CT without contrast

B) CT with contrast

C) MRI

D) Abdominal ultrasound

This patient has several potential causes for his abdominal pain that imaging may clarify. I think a contrast CT scan would be the most likely to provide helpful information. It is likely that if it were ordered, there may be hesitation by the radiologist to perform the scan with contrast because of the patient’s CKD.

Concern for contrast-induced kidney injury has limited diagnostic testing for many years. How strong is the evidence for contrast-induced kidney injury, and should we avoid testing that requires contrast in patients with CKD? McDonald and colleagues performed a meta-analysis with 13 studies meeting inclusion criteria, involving 25,950 patients.¹ They found no increased risk of acute kidney injury (AKI) in patients who received contrast medium compared with those who did not receive contrast; relative risk of AKI for those receiving contrast was 0.79 (confidence interval: 0.62-1.02). Importantly, there was no difference in AKI in patients with diabetes or CKD.

Ehmann et al. looked at renal outcomes in patients who received IV contrast when they presented to an emergency department with AKI.² They found that in patients with AKI, receiving contrast was not associated with persistent AKI at hospital discharge. Hinson and colleagues looked at patients arriving at the emergency department and needing imaging.³ They did a retrospective, cohort analysis of 17,934 patients who had CT with contrast, CT with no contrast, or no CT. Contrast administration was not associated with increased incidence of AKI (odds ratio, 0.96, CI: 0.85-1.08).

Aycock et al. did a meta-analysis of AKI after CT scanning, including 28 studies involving 107,335 patients.⁴ They found that compared with noncontrast CT, CT scanning with contrast was not associated with AKI (OR, 0.94, CI: 0.83-1.07). Elias and Aronson looked at the risk of AKI after contrast in patients receiving CT scans compared with those who received ventilation/perfusion scans to evaluate for pulmonary embolism.⁵ There were 44 AKI events (4.5%) in patients exposed to contrast media and 33 events (3.4%) in patients not exposed to contrast media (risk difference: 1.1%, 95% CI: -0.6% to 2.9%; OR, 1.39, CI: 0.86-2.26; P = .18).

Despite multiple studies showing no increased risk, there is still a concern that contrast can cause AKI.⁶ Animal models have shown iodinated contrast can have a deleterious effect on mitochondria and membrane function.⁶ Criticisms of the retrospective nature of many of the studies I have shared, and the lack of randomized, controlled trials are that there may be bias in these studies, as the highest-risk patients are the ones most likely not to receive contrast. In a joint guideline from the American College of Radiology and the National Kidney Foundation, this statement was made: “The risk of acute kidney injury developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated.”⁷ Their recommendation was to give contrast if needed in patients with glomerular filtration rates (GFRs) greater than 30.



Myth: Contrast-induced renal injury is a concern.

Clinical impact: For CT scanning, it is OK to give contrast when needed. A conservative cutoff for contrast use would be a GFR less than 30.
 

Dr. Paauw is professor of medicine in the Division of General Internal Medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at dpaauw@uw.edu.

References

1. McDonald JS et al. Radiology. 2013:267:119-128.

2. Ehmann MR et al. Intensive Care Med. 2023:49(2):205-215.

3. Hinson JS et al. Ann Emerg Med. 2017;69(5):577-586.

4. Aycock RD et al. Ann Emerg Med. 2018 Jan;71(1):44-53.

5. Elias A, Aronson D. Thromb Haemost. 2021 Jun;121(6):800-807.

6. Weisbord SD, du Cheryon D. Intensive Care Med. 2018;44(1):107-109.

7. Davenport MS et al. Radiology. 2020;294(3):660-668.

An experimental handheld ultrasonic device used in an office setting was shown to guide residual kidney stone fragments out of the body and markedly reduce the risk for relapse, researchers reported (Abstract MP29-10) at the 2024 annual meeting of the American Urological Association AUA in San Antonio, Texas.

Mathew Sorensen, MD, MS, an associate professor of urology at the University of Washington, Seattle, and director of the Comprehensive Metabolic Stone Clinic at the Puget Sound VA, said that the risk for relapse of kidney stones was 70% lower in the treatment group than in the control group.

“This is an ultrasound-based propulsion procedure that is not like anything else that has ever existed. There’s nothing else that’s like it,” Dr. Sorensen said. “Essentially, in a session in the office with no anesthesia, we can use ultrasound energy to focus on those fragments and try to push them out of the unfavorable areas of the kidney.”

Roughly 20%-30% of patients who undergo surgery to remove kidney stones have residual fragments that can ultimately cause pain and send them to the emergency department or into hospital admission for treatment.

In the new study, 82 patients with stone fragments ≤ 5 mm were randomly assigned to receive the ultrasound treatment — which Dr. Sorensen and his colleagues developed over the past decade — or no procedure.

During a median follow-up of 2.6 years, 20% of patients in the treatment group experienced relapse of stones compared with 50% of patients in the control group. 

Relapse was measured as the future occurrence of urgent medical visits for stone-related symptoms, surgeries, or growth of the residual fragments as measured on annual CT.

Dr. Sorensen and his colleagues found asymptomatic passage of fragments was twelvefold higher in the treatment group in the first 3 weeks (60% vs 5%). Asymptomatic passage was similar in both groups after 3 weeks.

Dr. Sorensen said that mild discomfort after the procedure was common, occurring in 38% of patients who underwent the treatment, but that it was short-lived and resolved without intervention; 8% of the treatment group and 7% of the control group had blood in the urine.

The propulsion device is available at two test sites in the University of Washington system; the manufacturer, SonoMotion Inc, a spinoff from the institution, is seeking US Food and Drug Administration approval for the technology, Dr. Sorensen said. 

David Schulsinger, MD, an associate professor in the Department of Urology at Stony Brook University Hospital, Stony Brook, New York, said that patients with stone fragments currently have two options: follow-up surgery or active surveillance.

“With this new device, we actually have the potential for doing one other thing, and that is treating these patients noninvasively and without anesthesia,” Dr. Schulsinger said. “Once it’s ready for prime time, I think [ultrasonic propulsion] will be very well accepted among urologists to manage patients with asymptomatic residual stones.”

Dr. Sorensen is an advisor and equity holder in SonoMotion Inc. Dr. Schulsinger reported no relevant financial conflicts of interest.

A version of this article first appeared on Medscape.com.

An experimental handheld ultrasonic device used in an office setting was shown to guide residual kidney stone fragments out of the body and markedly reduce the risk for relapse, researchers reported (Abstract MP29-10) at the 2024 annual meeting of the American Urological Association AUA in San Antonio, Texas.

Mathew Sorensen, MD, MS, an associate professor of urology at the University of Washington, Seattle, and director of the Comprehensive Metabolic Stone Clinic at the Puget Sound VA, said that the risk for relapse of kidney stones was 70% lower in the treatment group than in the control group.

“This is an ultrasound-based propulsion procedure that is not like anything else that has ever existed. There’s nothing else that’s like it,” Dr. Sorensen said. “Essentially, in a session in the office with no anesthesia, we can use ultrasound energy to focus on those fragments and try to push them out of the unfavorable areas of the kidney.”

Roughly 20%-30% of patients who undergo surgery to remove kidney stones have residual fragments that can ultimately cause pain and send them to the emergency department or into hospital admission for treatment.

In the new study, 82 patients with stone fragments ≤ 5 mm were randomly assigned to receive the ultrasound treatment — which Dr. Sorensen and his colleagues developed over the past decade — or no procedure.

During a median follow-up of 2.6 years, 20% of patients in the treatment group experienced relapse of stones compared with 50% of patients in the control group. 

Relapse was measured as the future occurrence of urgent medical visits for stone-related symptoms, surgeries, or growth of the residual fragments as measured on annual CT.

Dr. Sorensen and his colleagues found asymptomatic passage of fragments was twelvefold higher in the treatment group in the first 3 weeks (60% vs 5%). Asymptomatic passage was similar in both groups after 3 weeks.

Dr. Sorensen said that mild discomfort after the procedure was common, occurring in 38% of patients who underwent the treatment, but that it was short-lived and resolved without intervention; 8% of the treatment group and 7% of the control group had blood in the urine.

The propulsion device is available at two test sites in the University of Washington system; the manufacturer, SonoMotion Inc, a spinoff from the institution, is seeking US Food and Drug Administration approval for the technology, Dr. Sorensen said. 

David Schulsinger, MD, an associate professor in the Department of Urology at Stony Brook University Hospital, Stony Brook, New York, said that patients with stone fragments currently have two options: follow-up surgery or active surveillance.

“With this new device, we actually have the potential for doing one other thing, and that is treating these patients noninvasively and without anesthesia,” Dr. Schulsinger said. “Once it’s ready for prime time, I think [ultrasonic propulsion] will be very well accepted among urologists to manage patients with asymptomatic residual stones.”

Dr. Sorensen is an advisor and equity holder in SonoMotion Inc. Dr. Schulsinger reported no relevant financial conflicts of interest.

A version of this article first appeared on Medscape.com.

An experimental handheld ultrasonic device used in an office setting was shown to guide residual kidney stone fragments out of the body and markedly reduce the risk for relapse, researchers reported (Abstract MP29-10) at the 2024 annual meeting of the American Urological Association AUA in San Antonio, Texas.

Mathew Sorensen, MD, MS, an associate professor of urology at the University of Washington, Seattle, and director of the Comprehensive Metabolic Stone Clinic at the Puget Sound VA, said that the risk for relapse of kidney stones was 70% lower in the treatment group than in the control group.

“This is an ultrasound-based propulsion procedure that is not like anything else that has ever existed. There’s nothing else that’s like it,” Dr. Sorensen said. “Essentially, in a session in the office with no anesthesia, we can use ultrasound energy to focus on those fragments and try to push them out of the unfavorable areas of the kidney.”

Roughly 20%-30% of patients who undergo surgery to remove kidney stones have residual fragments that can ultimately cause pain and send them to the emergency department or into hospital admission for treatment.

In the new study, 82 patients with stone fragments ≤ 5 mm were randomly assigned to receive the ultrasound treatment — which Dr. Sorensen and his colleagues developed over the past decade — or no procedure.

During a median follow-up of 2.6 years, 20% of patients in the treatment group experienced relapse of stones compared with 50% of patients in the control group. 

Relapse was measured as the future occurrence of urgent medical visits for stone-related symptoms, surgeries, or growth of the residual fragments as measured on annual CT.

Dr. Sorensen and his colleagues found asymptomatic passage of fragments was twelvefold higher in the treatment group in the first 3 weeks (60% vs 5%). Asymptomatic passage was similar in both groups after 3 weeks.

Dr. Sorensen said that mild discomfort after the procedure was common, occurring in 38% of patients who underwent the treatment, but that it was short-lived and resolved without intervention; 8% of the treatment group and 7% of the control group had blood in the urine.

The propulsion device is available at two test sites in the University of Washington system; the manufacturer, SonoMotion Inc, a spinoff from the institution, is seeking US Food and Drug Administration approval for the technology, Dr. Sorensen said. 

David Schulsinger, MD, an associate professor in the Department of Urology at Stony Brook University Hospital, Stony Brook, New York, said that patients with stone fragments currently have two options: follow-up surgery or active surveillance.

“With this new device, we actually have the potential for doing one other thing, and that is treating these patients noninvasively and without anesthesia,” Dr. Schulsinger said. “Once it’s ready for prime time, I think [ultrasonic propulsion] will be very well accepted among urologists to manage patients with asymptomatic residual stones.”

Dr. Sorensen is an advisor and equity holder in SonoMotion Inc. Dr. Schulsinger reported no relevant financial conflicts of interest.

A version of this article first appeared on Medscape.com.

TOPLINE:

Nearly 90% of adults were at risk of developing cardiovascular-kidney-metabolic (CKM) syndrome between 2011 and 2020, according to new research published in JAMA.

METHODOLOGY:

• In 2023, the American Heart Association defined  to acknowledge how heart and kidney diseases, diabetes, and obesity interact and are increasingly co-occurring conditions.
• Researchers used data from the National Health and Nutrition Examination Survey between 2011 and 2020.
• More than 10,000 adults over age 20 years were included; all of them received a physical and fasting laboratory measurements and self-reported their cardiovascular disease (CVD) status.
• Researchers created categories for risk, ranging from 0 (no risk factors) to 4, using factors such as kidney disease, obesity, and hypertension.

TAKEAWAY:

• Nearly 90% of participants met the criteria for having a stage of the CKM syndrome, with rates remaining steady throughout the study period.Almost half of people met the criteria for stage 2 (having metabolic risk factors like hypertension or moderate- to high-risk chronic kidney disease).
• 14.6% met the criteria for advanced stage 3 (very high-risk chronic kidney disease or a high risk for 10-year CVD) and stage 4 CKM syndrome (established CVD) combined.
• Men, adults over age 65 years, and Black individuals were at a greater risk for advanced stages of the CKM syndrome.
• Almost half of people met the criteria for stage 2 (having metabolic risk factors like hypertension or moderate- to high-risk chronic kidney disease).
   
• 14.6% met the criteria for advanced stage 3 (very high-risk chronic kidney disease or a high risk for 10-year CVD) and stage 4 CKM syndrome (established CVD) combined.
   
• Men, adults over age 65 years, and Black individuals were at a greater risk for advanced stages of the CKM syndrome.

IN PRACTICE:

“Equitable health care approaches prioritizing CKM health are urgently needed,” the study authors wrote.

SOURCE:

The study was led by Muthiah Vaduganathan, MD, MPH, cardiologist and researcher at Brigham and Women’s Hospital, Harvard Medical School, Boston.

LIMITATIONS: 

Established CVD statuses were self-reported. Some data that would indicate advanced CKM stages were not available (eg, cardiac biomarkers, echocardiography, and coronary angiography), which may have led to an underestimation of rates.

DISCLOSURES:

One author received grants from Bristol Myers Squibb–Pfizer outside the submitted work. Dr. Vaduganathan received grants from and was an adviser and committee trial member for various pharmaceutical companies outside the submitted work. The authors reported no other disclosures.

A version of this article appeared on Medscape.com.

TOPLINE:

Nearly 90% of adults were at risk of developing cardiovascular-kidney-metabolic (CKM) syndrome between 2011 and 2020, according to new research published in JAMA.

METHODOLOGY:

• In 2023, the American Heart Association defined  to acknowledge how heart and kidney diseases, diabetes, and obesity interact and are increasingly co-occurring conditions.
• Researchers used data from the National Health and Nutrition Examination Survey between 2011 and 2020.
• More than 10,000 adults over age 20 years were included; all of them received a physical and fasting laboratory measurements and self-reported their cardiovascular disease (CVD) status.
• Researchers created categories for risk, ranging from 0 (no risk factors) to 4, using factors such as kidney disease, obesity, and hypertension.

TAKEAWAY:

• Nearly 90% of participants met the criteria for having a stage of the CKM syndrome, with rates remaining steady throughout the study period.Almost half of people met the criteria for stage 2 (having metabolic risk factors like hypertension or moderate- to high-risk chronic kidney disease).
• 14.6% met the criteria for advanced stage 3 (very high-risk chronic kidney disease or a high risk for 10-year CVD) and stage 4 CKM syndrome (established CVD) combined.
• Men, adults over age 65 years, and Black individuals were at a greater risk for advanced stages of the CKM syndrome.
• Almost half of people met the criteria for stage 2 (having metabolic risk factors like hypertension or moderate- to high-risk chronic kidney disease).
   
• 14.6% met the criteria for advanced stage 3 (very high-risk chronic kidney disease or a high risk for 10-year CVD) and stage 4 CKM syndrome (established CVD) combined.
   
• Men, adults over age 65 years, and Black individuals were at a greater risk for advanced stages of the CKM syndrome.

IN PRACTICE:

“Equitable health care approaches prioritizing CKM health are urgently needed,” the study authors wrote.

SOURCE:

The study was led by Muthiah Vaduganathan, MD, MPH, cardiologist and researcher at Brigham and Women’s Hospital, Harvard Medical School, Boston.

LIMITATIONS: 

Established CVD statuses were self-reported. Some data that would indicate advanced CKM stages were not available (eg, cardiac biomarkers, echocardiography, and coronary angiography), which may have led to an underestimation of rates.

DISCLOSURES:

One author received grants from Bristol Myers Squibb–Pfizer outside the submitted work. Dr. Vaduganathan received grants from and was an adviser and committee trial member for various pharmaceutical companies outside the submitted work. The authors reported no other disclosures.

A version of this article appeared on Medscape.com.

TOPLINE:

Nearly 90% of adults were at risk of developing cardiovascular-kidney-metabolic (CKM) syndrome between 2011 and 2020, according to new research published in JAMA.

METHODOLOGY:

• In 2023, the American Heart Association defined  to acknowledge how heart and kidney diseases, diabetes, and obesity interact and are increasingly co-occurring conditions.
• Researchers used data from the National Health and Nutrition Examination Survey between 2011 and 2020.
• More than 10,000 adults over age 20 years were included; all of them received a physical and fasting laboratory measurements and self-reported their cardiovascular disease (CVD) status.
• Researchers created categories for risk, ranging from 0 (no risk factors) to 4, using factors such as kidney disease, obesity, and hypertension.

TAKEAWAY:

• Nearly 90% of participants met the criteria for having a stage of the CKM syndrome, with rates remaining steady throughout the study period.Almost half of people met the criteria for stage 2 (having metabolic risk factors like hypertension or moderate- to high-risk chronic kidney disease).
• 14.6% met the criteria for advanced stage 3 (very high-risk chronic kidney disease or a high risk for 10-year CVD) and stage 4 CKM syndrome (established CVD) combined.
• Men, adults over age 65 years, and Black individuals were at a greater risk for advanced stages of the CKM syndrome.
• Almost half of people met the criteria for stage 2 (having metabolic risk factors like hypertension or moderate- to high-risk chronic kidney disease).
   
• 14.6% met the criteria for advanced stage 3 (very high-risk chronic kidney disease or a high risk for 10-year CVD) and stage 4 CKM syndrome (established CVD) combined.
   
• Men, adults over age 65 years, and Black individuals were at a greater risk for advanced stages of the CKM syndrome.

IN PRACTICE:

“Equitable health care approaches prioritizing CKM health are urgently needed,” the study authors wrote.

SOURCE:

The study was led by Muthiah Vaduganathan, MD, MPH, cardiologist and researcher at Brigham and Women’s Hospital, Harvard Medical School, Boston.

LIMITATIONS: 

Established CVD statuses were self-reported. Some data that would indicate advanced CKM stages were not available (eg, cardiac biomarkers, echocardiography, and coronary angiography), which may have led to an underestimation of rates.

DISCLOSURES:

One author received grants from Bristol Myers Squibb–Pfizer outside the submitted work. Dr. Vaduganathan received grants from and was an adviser and committee trial member for various pharmaceutical companies outside the submitted work. The authors reported no other disclosures.

A version of this article appeared on Medscape.com.

Older men with chronic kidney disease (CKD) show higher resting muscle sympathetic nerve activity, but not vascular stiffness, compared with older women, offering clues to the underlying reasons why men with CKD have a higher cardiovascular risk than do women with the disease.

“Although it is well established that sympathetic nerve system activity is chronically elevated in patients with impaired kidney function, we show for the first time that males with CKD have higher resting muscle sympathetic nerve activity compared with females with CKD,” report the authors on research published in the American Journal of Physiology-Renal Physiology.

“For clinicians, the key takeaway is the importance of recognizing sex-specific differences in sympathetic activity and vascular function when assessing cardiovascular risk in CKD patients,” first author Matias G. Zanuzzi, MD, of the Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, told this news organization.

In the general population, cardiovascular risk is lower in younger women vs men, but their risks converge in older age as women develop similar levels of sympathetic overactivity, vascular stiffness, and cardiovascular risk.

However, an exception to that pattern is seen in the CKD population, where men continue to have a higher cardiovascular mortality risk vs women even in older age.

Studies evaluating the reasons for that have been conflicting, with some reporting a tendency of higher muscle sympathetic nerve activity in older women compared with men and others suggest the opposite finding — lower activity vs men.

To further investigate, Dr. Zanuzzi and colleagues enrolled 129 participants, including 96 men and 33 women with stage III or IV CKD.

The mean age of the study participants was 64 years for men and65 years for women. Most had obesity, and importantly, more than 80% of participants in each group was Black. There were no significant differences between the groups in terms of body mass index or comorbidities, including smoking, diabetes, or hypertension.

At two separate study visits, vascular stiffness was assessed with carotid-femoral pulse wave velocity measurement, and resting muscle sympathetic nerve activity was measured using microneurography. 

The results showed that men with CKD had significantly higher resting muscle sympathetic nerve activity compared with women with CKD (68 vs 55 bursts per 100 heartbeats; P = .005), whereas no differences in vascular stiffness were observed between the genders (P = .248).

“The findings suggest that the higher cardiovascular disease risk observed in older males with CKD may be influenced by elevated sympathetic activity,” Dr. Zanuzzi explained.

“However, the lack of significant differences in vascular stiffness between genders implies that additional factors beyond vascular remodeling may contribute to the observed sex-specific differences in cardiovascular risk,” he said.

Of note, resting vascular stiffness was not associated with muscular sympathetic nerve activity in either men or women, which was surprising to the authors, Dr. Zanuzzi noted.

“This underscores the multifactorial nature of vascular pathophysiology in CKD and underscores the need for further research to unravel the underlying mechanisms.”

In other findings, although prior studies have shown a positive correlation between age and resting muscle sympathetic nerve activity in White, healthy women and men without obesity,, no similar relationship was observed in men or women with CKD.

“These findings suggest that the protective effect of younger age on sympathetic function may not be present in the setting of decreased kidney function in both males and females,” the authors note.

In addition, whereas previous research has shown a clear association between sympathetic overactivity and a wide variety of measures of obesity, in the current study, that association was only observed in men with CKD.

Important limitations of the study include the cross-sectional design and that the population was predominantly Black, Dr. Zanuzzi noted.

“Generalizability to other demographic groups may be limited, and future longitudinal studies are needed to validate these findings and explore potential causal relationships,” he said.

The findings underscore “the need for novel therapeutic approaches targeting sympathetic overactivity and vascular stiffness in CKD patients, especially considering the observed sex-specific differences,” Dr. Zanuzzi added. 

“Potential interventions may include pharmacological agents that modulate sympathetic tone or vascular remodeling pathways,” he said.

“Lifestyle modifications focusing on stress reduction and cardiovascular health promotion could also play a crucial role in mitigating cardiovascular risk.”

Dr. Zanuzzi concluded that “tailoring treatment strategies to address these differences may lead to more personalized and effective management approaches, ultimately improving clinical outcomes in this high-risk population.”

The authors had no disclosures to report.

A version of this article first appeared on Medscape.com.

Older men with chronic kidney disease (CKD) show higher resting muscle sympathetic nerve activity, but not vascular stiffness, compared with older women, offering clues to the underlying reasons why men with CKD have a higher cardiovascular risk than do women with the disease.

“Although it is well established that sympathetic nerve system activity is chronically elevated in patients with impaired kidney function, we show for the first time that males with CKD have higher resting muscle sympathetic nerve activity compared with females with CKD,” report the authors on research published in the American Journal of Physiology-Renal Physiology.

“For clinicians, the key takeaway is the importance of recognizing sex-specific differences in sympathetic activity and vascular function when assessing cardiovascular risk in CKD patients,” first author Matias G. Zanuzzi, MD, of the Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, told this news organization.

In the general population, cardiovascular risk is lower in younger women vs men, but their risks converge in older age as women develop similar levels of sympathetic overactivity, vascular stiffness, and cardiovascular risk.

However, an exception to that pattern is seen in the CKD population, where men continue to have a higher cardiovascular mortality risk vs women even in older age.

Studies evaluating the reasons for that have been conflicting, with some reporting a tendency of higher muscle sympathetic nerve activity in older women compared with men and others suggest the opposite finding — lower activity vs men.

To further investigate, Dr. Zanuzzi and colleagues enrolled 129 participants, including 96 men and 33 women with stage III or IV CKD.

The mean age of the study participants was 64 years for men and65 years for women. Most had obesity, and importantly, more than 80% of participants in each group was Black. There were no significant differences between the groups in terms of body mass index or comorbidities, including smoking, diabetes, or hypertension.

At two separate study visits, vascular stiffness was assessed with carotid-femoral pulse wave velocity measurement, and resting muscle sympathetic nerve activity was measured using microneurography. 

The results showed that men with CKD had significantly higher resting muscle sympathetic nerve activity compared with women with CKD (68 vs 55 bursts per 100 heartbeats; P = .005), whereas no differences in vascular stiffness were observed between the genders (P = .248).

“The findings suggest that the higher cardiovascular disease risk observed in older males with CKD may be influenced by elevated sympathetic activity,” Dr. Zanuzzi explained.

“However, the lack of significant differences in vascular stiffness between genders implies that additional factors beyond vascular remodeling may contribute to the observed sex-specific differences in cardiovascular risk,” he said.

Of note, resting vascular stiffness was not associated with muscular sympathetic nerve activity in either men or women, which was surprising to the authors, Dr. Zanuzzi noted.

“This underscores the multifactorial nature of vascular pathophysiology in CKD and underscores the need for further research to unravel the underlying mechanisms.”

In other findings, although prior studies have shown a positive correlation between age and resting muscle sympathetic nerve activity in White, healthy women and men without obesity,, no similar relationship was observed in men or women with CKD.

“These findings suggest that the protective effect of younger age on sympathetic function may not be present in the setting of decreased kidney function in both males and females,” the authors note.

In addition, whereas previous research has shown a clear association between sympathetic overactivity and a wide variety of measures of obesity, in the current study, that association was only observed in men with CKD.

Important limitations of the study include the cross-sectional design and that the population was predominantly Black, Dr. Zanuzzi noted.

“Generalizability to other demographic groups may be limited, and future longitudinal studies are needed to validate these findings and explore potential causal relationships,” he said.

The findings underscore “the need for novel therapeutic approaches targeting sympathetic overactivity and vascular stiffness in CKD patients, especially considering the observed sex-specific differences,” Dr. Zanuzzi added. 

“Potential interventions may include pharmacological agents that modulate sympathetic tone or vascular remodeling pathways,” he said.

“Lifestyle modifications focusing on stress reduction and cardiovascular health promotion could also play a crucial role in mitigating cardiovascular risk.”

Dr. Zanuzzi concluded that “tailoring treatment strategies to address these differences may lead to more personalized and effective management approaches, ultimately improving clinical outcomes in this high-risk population.”

The authors had no disclosures to report.

A version of this article first appeared on Medscape.com.

Older men with chronic kidney disease (CKD) show higher resting muscle sympathetic nerve activity, but not vascular stiffness, compared with older women, offering clues to the underlying reasons why men with CKD have a higher cardiovascular risk than do women with the disease.

“Although it is well established that sympathetic nerve system activity is chronically elevated in patients with impaired kidney function, we show for the first time that males with CKD have higher resting muscle sympathetic nerve activity compared with females with CKD,” report the authors on research published in the American Journal of Physiology-Renal Physiology.

“For clinicians, the key takeaway is the importance of recognizing sex-specific differences in sympathetic activity and vascular function when assessing cardiovascular risk in CKD patients,” first author Matias G. Zanuzzi, MD, of the Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, told this news organization.

In the general population, cardiovascular risk is lower in younger women vs men, but their risks converge in older age as women develop similar levels of sympathetic overactivity, vascular stiffness, and cardiovascular risk.

However, an exception to that pattern is seen in the CKD population, where men continue to have a higher cardiovascular mortality risk vs women even in older age.

Studies evaluating the reasons for that have been conflicting, with some reporting a tendency of higher muscle sympathetic nerve activity in older women compared with men and others suggest the opposite finding — lower activity vs men.

To further investigate, Dr. Zanuzzi and colleagues enrolled 129 participants, including 96 men and 33 women with stage III or IV CKD.

The mean age of the study participants was 64 years for men and65 years for women. Most had obesity, and importantly, more than 80% of participants in each group was Black. There were no significant differences between the groups in terms of body mass index or comorbidities, including smoking, diabetes, or hypertension.

At two separate study visits, vascular stiffness was assessed with carotid-femoral pulse wave velocity measurement, and resting muscle sympathetic nerve activity was measured using microneurography. 

The results showed that men with CKD had significantly higher resting muscle sympathetic nerve activity compared with women with CKD (68 vs 55 bursts per 100 heartbeats; P = .005), whereas no differences in vascular stiffness were observed between the genders (P = .248).

“The findings suggest that the higher cardiovascular disease risk observed in older males with CKD may be influenced by elevated sympathetic activity,” Dr. Zanuzzi explained.

“However, the lack of significant differences in vascular stiffness between genders implies that additional factors beyond vascular remodeling may contribute to the observed sex-specific differences in cardiovascular risk,” he said.

Of note, resting vascular stiffness was not associated with muscular sympathetic nerve activity in either men or women, which was surprising to the authors, Dr. Zanuzzi noted.

“This underscores the multifactorial nature of vascular pathophysiology in CKD and underscores the need for further research to unravel the underlying mechanisms.”

In other findings, although prior studies have shown a positive correlation between age and resting muscle sympathetic nerve activity in White, healthy women and men without obesity,, no similar relationship was observed in men or women with CKD.

“These findings suggest that the protective effect of younger age on sympathetic function may not be present in the setting of decreased kidney function in both males and females,” the authors note.

In addition, whereas previous research has shown a clear association between sympathetic overactivity and a wide variety of measures of obesity, in the current study, that association was only observed in men with CKD.

Important limitations of the study include the cross-sectional design and that the population was predominantly Black, Dr. Zanuzzi noted.

“Generalizability to other demographic groups may be limited, and future longitudinal studies are needed to validate these findings and explore potential causal relationships,” he said.

The findings underscore “the need for novel therapeutic approaches targeting sympathetic overactivity and vascular stiffness in CKD patients, especially considering the observed sex-specific differences,” Dr. Zanuzzi added. 

“Potential interventions may include pharmacological agents that modulate sympathetic tone or vascular remodeling pathways,” he said.

“Lifestyle modifications focusing on stress reduction and cardiovascular health promotion could also play a crucial role in mitigating cardiovascular risk.”

Dr. Zanuzzi concluded that “tailoring treatment strategies to address these differences may lead to more personalized and effective management approaches, ultimately improving clinical outcomes in this high-risk population.”

The authors had no disclosures to report.

A version of this article first appeared on Medscape.com.