COVID-19 long-haulers show elevated risks for kidney damage, including ESKD
Individuals who survived for at least 30 days after contracting COVID-19 — considered the acute phase of the illness — were at greater risk for adverse kidney outcomes, even if the infection was deemed mild, study results showed.
This increased risk in survivors, especially for those considered “COVID-19 long-haulers,” was found for several types of kidney damage, including acute kidney injury, eGFR decline and end-stage kidney disease. Based on their findings, investigators suggested that 510,000 of the more than 38 million Americans who have had COVID-19 may also have kidney injury or kidney disease.
Kidney damage in ‘COVID-19 long-haulers’
“Our findings emphasize the critical importance of paying attention to kidney function and disease in caring for patients who have had COVID-19,” Ziyad Al-Aly, MD, assistant professor of medicine at Washington University and senior author of the paper, said in a related press release. “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.”
Utilizing data from the U.S. Department of Veterans Affairs, Al-Aly and colleagues identified 89,216 individuals (median age, 65.5 years; 90.1% men; 67.8% white) who survived the acute phase of COVID-19 and 1,637,467 non-infected individuals (average age, 68.7 years; 91.3% men; 73.7% white) to serve as controls. Of the COVID-19 cohort, 13.9% required hospitalization, with 4.6% admitted to ICUs.
In addition to AKI, eGFR decline and ESKD, researchers considered the risk for major adverse kidney events, defined as eGFR decline of at least 50%, ESKD or all-cause mortality.
Median follow-up time was 164 days for those with COVID-19 and 172 days for controls.
Results showed that all individuals who survived COVID-19 beyond the acute phase had a higher risk for AKI (adjusted HR = 1.94; 95% CI, 1.86-2.04), eGFR decline of at least 30% (aHR = 1.25; 95% CI, 1.14-1.37), eGFR decline of at least 40% (aHR = 1.44; 1.37-1.51), eGFR decline of at least 50% (aHR = 1.62; 95% CI, 1.51-1.74), ESKD (aHR = 2.96; 95% CI, 2.49-3.51) and major adverse kidney events (aHR = 1.66; 95% CI, 1.58-1.74).
Kidney outcomes based on COVID-19 severity
The increase in risks of post-acute kidney outcomes was found to be graded according to the severity of the acute infection, or “whether patients were non-hospitalized, hospitalized or admitted to intensive care.”
Specific findings indicated that although patients admitted to the ICU or who were hospitalized had the greatest risk for eGFR decline of 30% or more, patients with milder COVID-19 cases were found to have 1.09 times the risk of non-infected controls.
“People who were hospitalized for COVID-19 or needed ICU care are at the highest risk. But the risk is not zero for those who had milder cases,” Al-Aly said. “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.”
Further, compared with patients who did not become infected, patients who had COVID-19 but did not require hospitalization had a 15% higher risk for a major adverse kidney event, a 30% higher risk for developing AKI and a 215% higher risk for acquiring ESKD.
All COVID-19 survivors exhibited excess eGFR decline, with non-hospitalized patients showing a decrease of -3.26 mL/min/1.73m2 per year, hospitalized patients showing a decrease of -5.2 mL/min/1.73m2 per year and those admitted to intensive care showing a decline of -7.69 mL/min/1.73m2 per year.
Contending that “kidney disease is an important facet of the multifaceted long COVID-19,” Al-Aly said it is imperative to identify kidney dysfunction early before damage progresses.
“But kidney problems are silent problems that won’t be found until somebody checks the bloodwork,” he said. “Based on our research, it’s especially important that health care providers do this for people who have had COVID-19. Otherwise, we’ll miss a lot of people and, sadly, we’ll be dealing with more advanced kidney diseases down the road.”