ST. LOUIS — A study by Washington University researchers found that people who tested positive for COVID-19 were more likely to experience a significant decline in kidney function.
The study found an increased chance of developing kidney damage as well as chronic and end-stage kidney diseases in people who tested positive for COVID-19. Researchers said the effects were most noticeable in people who had severe cases and were considered "long-haulers," but people who suffered only minor symptoms initially were also at a slightly higher risk.
Of the patients analyzed in the study, those who ended up in the ICU due to COVID-19 were seven times more likely to experience a major adverse kidney event, eight times more likely to suffer an acute kidney injury and 13 times more likely to suffer end-stage kidney disease than people who did not get COVID-19. Patients who suffered only mild COVID-19 symptoms also saw an increase in kidney issues: a 15% increase in major adverse kidney events and 30% increase in acute kidney injuries while being more than twice as likely to suffer end-stage kidney disease.
“People who were hospitalized for COVID-19 or needed ICU care are at the highest risk,” said senior author Dr. Ziyad Al-Aly, an assistant professor of medicine at Washington University. “But the risk is not zero for those who had milder cases. In fact, it’s significant. And we need to remember that we don’t yet know the health implications for long-haulers in the coming years.”
The researchers analyzed de-identified medical records in a U.S. Department of Veterans Affairs database, the largest integrated health care delivery system in the country. In all, they analyzed data of 1.7 million veterans who tested positive for COVID-19 but were otherwise healthy. Most of the people in the database were men in their 60s, but it also included more than 150,000 women, 8,817 of whom tested positive for COVID-19.
The study found that about 5% of patients experienced a 30% decrease in glomerular filtration rates, a metric used to assess kidney function. It is found using a simple blood test that measures the level of waste in the blood that is typically filtered by the kidneys.
Researchers said the findings highlight the importance of monitoring kidney function. Kidney dysfunction does not typically produce pain or other symptoms. Because of that, the National Kidney Foundation estimates about 90% of people with ailing kidneys don't know it.
“If kidney care isn’t an integral part of COVID-19 post-acute care strategy, then we will miss opportunities to help potentially hundreds of thousands of people who have no idea that their kidney function has declined due to this virus," Dr. Al-Aly said in a press release.
Researchers said early recognition could make a big difference, as kidney decline can often be treated with medication if caught in the earlier stages.