Even mild initial cases of COVID-19 — but especially more severe cases — can damage kidney function months after the initial infection, according to a new study published in the Journal of the American Society of Nephrology.
It’s already well known that severe COVID-19 can cause acute kidney injury, with many people hospitalized for the viral infection experiencing this dangerous complication. But there is far less data on long-term kidney problems related to COVID-19, since there is no system in place to monitor these kinds of long-term outcomes outside of specific studies.
To get cutting-edge diabetes news, strategies for blood glucose management, nutrition tips, healthy recipes, and more delivered straight to your inbox, sign up for our free newsletters!
For the latest study, researchers looked at medical records from over 1.7 million people who received health care through the U.S. Veterans Health Administration. They identified 89,216 people who survived COVID-19 (for at least 30 days) between March 2020 and March 2021, along with 1,637,467 people who didn’t develop COVID-19. Kidney-related outcomes between the two groups were compared, including the risk of developing acute kidney injury (after the initial 30-day period for those who had COVID-19), a decline in kidney function as measured by estimated glomerular filtration rate (eGFR), and developing end-stage kidney disease. The researchers also looked at an outcome called major adverse kidney events (MAKE), defined as any one or more of the following — an eGFR decline of at least 50%, developing end-stage kidney disease, or death from all causes after adjusting for the likelihood of dying from non-kidney causes.
COVID linked to increased risk of acute kidney injury
The researchers found that after the initial 30-day period after developing COVID-19, study participants who had the infection were still 94% more likely to develop an acute kidney injury during the study period than those who didn’t have COVID-19. What’s more, they were 25% more likely to see an eGFR decline of at least 30%, 44% more likely to see an eGFR decline of at least 40%, and 62% more likely to see an eGFR decline of at least 50%. When it came to major adverse kidney events, COVID-19 survivors were 66% more likely to experience at least one of the outcomes in the category. Not surprisingly, all kidney outcomes in COVID-19 survivors were related to how severe the initial infection was — as indicated by whether someone was not hospitalized, was hospitalized without admission to the intensive care unit (ICU), or was admitted to the ICU during hospitalization.
According to the study authors, these results demonstrate the importance of evaluating kidney function in people who survive COVID-19 — even if someone had only a mild initial infection. Since people with diabetes are already at higher risk for poor kidney-related outcomes, it may be even more important for these individuals to have their kidney function monitored after developing COVID-19. It’s important to note that most kidney problems — even serious ones — don’t cause any symptoms, and people may not know they have reduced kidney function until they develop late-stage kidney disease unless they have their kidney function monitored.
Want to learn more about coronavirus and diabetes? Read our latest COVID-19 updates.