COVID-19 long-haulers at risk of developing kidney damage, disease

Sept. 6, 2021

A study by researchers at Washington University School of Medicine in St. Louis and the Veterans Affairs St. Louis Health Care System reported in a release, that people who have had COVID-19, including those with mild cases, are at an increased risk of developing kidney damage as well as chronic and end-stage kidney diseases.

Research continues to mount indicating that many people who’ve had COVID-19 go on to suffer a range of adverse conditions months after their initial infections. A deep dive into federal health data adds to those concerns, pointing to a significant decline in kidney function among those dubbed COVID-19 long-haulers — and even among those who had mild infections of the virus.

The study was published in the Journal of the American Society of Nephrology.

Known as the silent killer, kidney dysfunction and disease tend to be free of pain and other symptoms — so much so that the National Kidney Foundation estimates that 90% of people with ailing kidneys don’t know it. Kidney disease affects 37 million people in the U.S. and is one of the nation’s leading causes of death.

“Our findings emphasize the critical importance of paying attention to kidney function and disease in caring for patients who have had COVID-19,” said senior author Ziyad Al-Aly, MD, an Assistant Professor of Medicine at Washington University. “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. This is in addition to the millions of Americans who suffer from kidney disease not caused by COVID-19.”

The findings coincide with a surge in COVID-19 infections spurred by the delta variant. More than 38 million people have been diagnosed with the virus since the pandemic started.

“Based on our research, we believe that 510,000 of those people who have had COVID-19 may have kidney injury or disease,” Al-Aly said.

The COVID-19 patients in the study were mostly men and in their late 60s; however, the researchers also analyzed data that included 151,289 women — including 8,817 with COVID-19 — and adults of all ages. Among the COVID-19 patients, 12,376 (13.9%) required hospitalization, including 4,146 (4.6%) who were admitted to intensive care units (ICUs).

Compared with patients who did not become infected, people who contracted the virus but did not need to be hospitalized for it had a 15% higher risk of suffering from a major adverse kidney event such as chronic kidney disease, a 30% higher risk of developing acute kidney injury and a 215% (more than twofold) higher risk of acquiring end-stage kidney disease. The latter occurs when the kidneys can no longer effectively remove waste from the body. In such cases, dialysis or a kidney transplant is needed to keep patients alive.

The risk increased for patients hospitalized for COVID-19, and considerably so for those who were in the ICU for the virus: seven times the risk of experiencing a major adverse kidney event, eight times the risk of acute kidney injury and 13 times the risk of end-stage kidney disease.

After the initial 30 days of COVID-19 infection, 4,757 (5.3%) of the patients experienced a decrease of 30% or more in glomerular filtration rates (GFR), which physicians use to assess kidney function and, if applicable, determine the severity of kidney disease. The rate is determined by a simple blood test that measures levels of creatinine, a waste product in the blood that is filtered by the kidneys and discarded into urine.

The researchers found that people who had milder COVID-19 cases had 1.09 times the risk of having an estimated GFR decline of 30% or more. For hospitalized COVID-19 patients not in intensive care units, there was two times the risk of having an estimated GFR decrease of 30% or more, while intensive care unit patients were at three times the risk of experiencing an estimated GFR drop of 30% or more.

Washington University School of Medicine in St. Louis

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