Is “Runner’s Kidney” a Thing?

Q) Many of my patients are athletes. I recall reading something about kidney disease in marathon runners. Am I remembering correctly?

Although data on acute kidney injury (AKI) in marathon runners are limited, two recent studies have added to our knowledge. In 2017, Mansour et al studied 22 marathon runners, collecting urine and blood samples 24 hours before, immediately after, and 24 hours after a race. The results showed that in 82% of the subjects, serum creatinine increased to a level correlated with stage 1 or 2 AKI (as defined by the Acute Kidney Injury Network criteria).¹

Based on urine microscopy results, as well as serum creatinine and novel biomarker levels, the researchers concluded that the runners’ AKI was caused by acute tubular injury—likely induced by ischemia. However, the subjects did not show any evidence of chronic kidney disease (CKD), despite years of running and intensive training. One theory: Habitual running might condition the kidneys to transient ischemic conditions—in other words, they build tolerance to repetitive injury over time.¹

Continue to: The other recent study

The other recent study examined use of NSAIDs by ultramarathon runners (ie, those who run more than 26.219 miles). In an intention-to-treat analysis, 52% of runners taking ibuprofen developed AKI, compared with 34% of those receiving placebo; the number needed to treat was 5.5. AKI was also more severe in NSAID users than in placebo users. The results were not statistically significant due to an underpowered study (N = 89). However, the authors also observed that slower runners were less likely to develop AKI, and those who lost the most weight during the race were more likely to develop AKI—suggesting that lower intensity running and adequate hydration may help prevent kidney injury.²

In summary: While marathon runners are prone to AKI, the injury seems to be transient and does not progress to CKD. Furthermore, use of NSAIDs during endurance running may contribute to AKI development, so patients should be advised to use caution with these analgesics. Finally, remind your endurance runners to stay hydrated, since it may help to limit kidney damage. As for the casual runner? The impact on the kidney remains unclear and needs further investigation. —DSW

Danielle S. Wentworth, MSN, FNP-BC
Division of Nephrology, University of Viriginia Health System, Charlottesville

Q) Many of my patients are athletes. I recall reading something about kidney disease in marathon runners. Am I remembering correctly?

Although data on acute kidney injury (AKI) in marathon runners are limited, two recent studies have added to our knowledge. In 2017, Mansour et al studied 22 marathon runners, collecting urine and blood samples 24 hours before, immediately after, and 24 hours after a race. The results showed that in 82% of the subjects, serum creatinine increased to a level correlated with stage 1 or 2 AKI (as defined by the Acute Kidney Injury Network criteria).¹

Based on urine microscopy results, as well as serum creatinine and novel biomarker levels, the researchers concluded that the runners’ AKI was caused by acute tubular injury—likely induced by ischemia. However, the subjects did not show any evidence of chronic kidney disease (CKD), despite years of running and intensive training. One theory: Habitual running might condition the kidneys to transient ischemic conditions—in other words, they build tolerance to repetitive injury over time.¹

Continue to: The other recent study

The other recent study examined use of NSAIDs by ultramarathon runners (ie, those who run more than 26.219 miles). In an intention-to-treat analysis, 52% of runners taking ibuprofen developed AKI, compared with 34% of those receiving placebo; the number needed to treat was 5.5. AKI was also more severe in NSAID users than in placebo users. The results were not statistically significant due to an underpowered study (N = 89). However, the authors also observed that slower runners were less likely to develop AKI, and those who lost the most weight during the race were more likely to develop AKI—suggesting that lower intensity running and adequate hydration may help prevent kidney injury.²

In summary: While marathon runners are prone to AKI, the injury seems to be transient and does not progress to CKD. Furthermore, use of NSAIDs during endurance running may contribute to AKI development, so patients should be advised to use caution with these analgesics. Finally, remind your endurance runners to stay hydrated, since it may help to limit kidney damage. As for the casual runner? The impact on the kidney remains unclear and needs further investigation. —DSW

Danielle S. Wentworth, MSN, FNP-BC
Division of Nephrology, University of Viriginia Health System, Charlottesville

Q) Many of my patients are athletes. I recall reading something about kidney disease in marathon runners. Am I remembering correctly?

Although data on acute kidney injury (AKI) in marathon runners are limited, two recent studies have added to our knowledge. In 2017, Mansour et al studied 22 marathon runners, collecting urine and blood samples 24 hours before, immediately after, and 24 hours after a race. The results showed that in 82% of the subjects, serum creatinine increased to a level correlated with stage 1 or 2 AKI (as defined by the Acute Kidney Injury Network criteria).¹

Based on urine microscopy results, as well as serum creatinine and novel biomarker levels, the researchers concluded that the runners’ AKI was caused by acute tubular injury—likely induced by ischemia. However, the subjects did not show any evidence of chronic kidney disease (CKD), despite years of running and intensive training. One theory: Habitual running might condition the kidneys to transient ischemic conditions—in other words, they build tolerance to repetitive injury over time.¹

Continue to: The other recent study

The other recent study examined use of NSAIDs by ultramarathon runners (ie, those who run more than 26.219 miles). In an intention-to-treat analysis, 52% of runners taking ibuprofen developed AKI, compared with 34% of those receiving placebo; the number needed to treat was 5.5. AKI was also more severe in NSAID users than in placebo users. The results were not statistically significant due to an underpowered study (N = 89). However, the authors also observed that slower runners were less likely to develop AKI, and those who lost the most weight during the race were more likely to develop AKI—suggesting that lower intensity running and adequate hydration may help prevent kidney injury.²

In summary: While marathon runners are prone to AKI, the injury seems to be transient and does not progress to CKD. Furthermore, use of NSAIDs during endurance running may contribute to AKI development, so patients should be advised to use caution with these analgesics. Finally, remind your endurance runners to stay hydrated, since it may help to limit kidney damage. As for the casual runner? The impact on the kidney remains unclear and needs further investigation. —DSW

Danielle S. Wentworth, MSN, FNP-BC
Division of Nephrology, University of Viriginia Health System, Charlottesville