“When you start controlling for all those chronic conditions, a lot of symptoms fall out,” Dr. Horberg told this news organization. “Plus, when you start comparing to the COVID-negative population, especially in the first 30 days of your positive diagnosis, actually, the COVID-negative patients have essentially almost the same amount, sometimes more.”
For instance, in the first month after diagnosis, though people with COVID reported anxiety symptoms after their diagnoses, people who’d never had COVID were coming in even more often with that symptom. And although gastrointestinal disorders were common in people who’d had COVID, they were just as likely in people who had not. Nausea and vomiting were actually 19% more common in people without COVID than in those with it. And people without COVID were nearly twice as likely to develop nutritional and endocrine disorders.
In the longer run, people who’d had COVID were 25% more likely to develop dysrhythmias, 20% more likely to develop diabetes, 60% more likely to develop fatigue, 21% more likely to develop genitourinary conditions, 39% more likely to develop chest pains, and a full 3.88 times more likely to develop trouble with olfaction.
And although people who’d had COVID were numerically 5% more likely to develop both abdominal pain and vertigo, 4% more likely to develop nervous system disorders, and 1% more likely to develop anxiety disorders longer term, none of those reached statistical significance.
The only diagnosis that doesn’t make sense to Dr. Horberg is diabetes.
“At this point I don’t think it’s been fully explained,” Dr. Horberg said. “I don’t think COVID is affecting the pancreas. But I do think that these are people who probably sought medical care, who hadn’t been seeking medical care and that the findings of diabetes were incidental diagnoses.”
Still, Dr. Horberg isn’t saying never on that. “As they say, more research is needed,” he added.
Ready to define long COVID?
As an intensive care unit physician and pulmonologist, Michael Risbano, MD, assistant professor of medicine at the University of Pittsburgh, has seen a lot of COVID. As the co-manager of the medical system’s post-COVID clinic, he’s also seen a lot of people coming in for help with what could be long COVID. When he saw the data from Dr. Horberg’s presentation, at first it seemed to confirm what he’d already known. But then he looked further.
“Well, this is actually making sense,” Dr. Risbano thought. At his clinic, it’s been an ongoing challenge to tease out what symptoms existed before COVID. Unlike Kaiser, the University of Pittsburgh Medical Center is not a closed system.
“We know some people who tend to get sick [with COVID] have some underlying medical issues already,” Dr. Risbano said in an interview. “But we don’t always have a good baseline as to what they were like beforehand, so we don’t always know what’s changed.”
He said the study design here, though retrospective and based on chart review rather than prospective observation, starts to put symptoms into the larger context of a patient’s life. And the diabetes association really stood out to him. He recalled one patient who, when she was admitted to the ICU, had a hemoglobin A1c that was totally normal. But when that patient returned a few months later, her blood sugar had skyrocketed.
“It was sky-high, like 13, and she was in diabetic ketoacidosis,” he said. “I know that’s an N of 1, but my wife is a dietitian and a case manager, and she’s having a lot of people coming in with a new diagnosis of diabetes.”
Still, he said he’s not sure that the conditions the study identified should be the basis for a definition of long COVID.
“I don’t know if you can come up with a definition out of this,” he said. “But I think this is at least helpful in telling us what disease states are different pre- and post-COVID, and what sorts of diagnoses clinicians should look for when a patient comes in after having a COVID diagnosis.”
Dr. Horberg and Dr. Risbano have disclosed no relevant financial relationships. The study was funded by the National Institute of Allergy and Infectious Diseases at the National Institutes of Health.
A version of this article first appeared on Medscape.com.