By Amy Norton
HealthDay reporter
THURSDAY, September 2, 2021 (HealthDay News) – People hospitalized for COVID-19, and even some with milder cases, may experience permanent kidney damage, new research shows.
The study of more than 1.7 million patients in the US Veterans Affairs system heightened concerns about the ongoing effects of COVID – especially among people who are so sick they need to be hospitalized.
The researchers found that months after their initial infection, COVID survivors were at increased risk of various types of kidney damage – from impaired kidney function to advanced kidney failure.
People who were most critically ill – who needed intensive care care – were at the highest risk of long-term kidney damage.
Likewise, patients who had developed acute kidney damage during their COVID hospitalization had higher risks than COVID patients without apparent kidney problems during their hospital stay.
What is striking, however, is that these last-named patients were not out of the woods, said Dr. F. Perry Wilson, a kidney specialist who was not involved in the study.
They were still two to five times more likely to develop some level of kidney dysfunction or disease than VA patients who were not diagnosed with COVID.
“I have noticed that these risks are seen across the board even in patients who did not have acute kidney damage when they were admitted to the hospital,” said Wilson, associate professor at the Yale School of Medicine in New Haven, Conn.
There are some questions about how the kidney problems are specifically related to COVID or the illness in the hospital, according to Wilson. For example, it’s unclear how their kidney function would compare to that of patients hospitalized for the flu.
However, the study found that even VA patients sick with COVID at home were at increased risk of kidney problems.
Inflammation to blame?
“There were risks, albeit minor ones, in these patients who never had major problems when sick,” said lead researcher Dr. Ziyad Al-Aly, Assistant Professor at Washington University School of Medicine in St. Louis.
Wilson said the “big question” was why?
continuation
“Does this reflect sustained stimulation and inflammation of the immune system?” he said. “More research will be needed to find out.”
The results – published September 1 in the Journal of the American Society of Nephrology – are based on medical records from more than 1.7 million VA patients. Of these, 89,216 were diagnosed with COVID between March 2020 and March 2021 and were still alive 30 days later.
The study looked at patients’ risk of developing various types of kidney problems in the months past this 30-day mark.
Overall, COVID patients were more likely to have seen a significant drop in kidney glomerular filtration rate (GFR), a measure of how well the organs are filtering waste materials from the blood.
Just over 5% of COVID patients had a GFR drop of 30% or more, the study found. And compared to the general VA patient population, their risk was 25% higher.
Because adults naturally lose about 1% of their kidney function each year, a 30% decrease in GFR equates to a 30 year loss of kidney function, according to Wilson.
The study also looked at the risk of acute kidney damage, in which organs suddenly lose their function. It can cause symptoms such as swelling in the legs, fatigue, and difficulty breathing, but sometimes it doesn’t cause any obvious problems.
COVID patients were almost twice as likely to develop acute kidney damage, although this varied depending on the initial COVID severity.
Will the damage continue?
Those who were hospitalized were five to eight times more likely than non-COVID patients to develop acute kidney damage; People who got COVID at home were at 30% higher risk than the non-COVID group.
It is not yet known what this all means for long-term kidney health for COVID patients, Al-Aly said.
One question now, he noted, is whether the GFR decline will level off in some patients.
As for acute kidney damage, people can recover from it without permanent damage, Wilson said. And if a drop in GFR is related to acute kidney damage, he noted, it may well recover.
continuation
Some patients in the study developed end-stage kidney failure. Those chances were greatest among COVID patients who were in the intensive care unit: They developed the disease at the rate of about 21 cases per 1,000 patients per year – which was their risk 13 times higher than other VA patients. Minor risks were also seen in other COVID patients who were hospitalized or not.
One limitation of the study is that the VA patients were predominantly older men. It is unclear how the results apply in general, according to Al-Aly.
The risks for non-inpatients are also somewhat unclear. They are far from a unified group, both doctors said.
Wilson suspects that people who are only mildly affected by COVID are unlikely to develop kidney problems, while those who are “really unconscious for weeks” may be at a relatively higher risk.
The good news, Al-Aly said, is that kidney dysfunction can be easily identified by simple blood tests during visits to primary care.
Wilson said some sort of check-up could be worthwhile for people who are more seriously ill with COVID.
More information
The National Kidney Foundation has more about COVID-19 and kidney disease.
SOURCES: Ziyad Al-Aly, MD, Assistant Professor, Medicine, Washington University School of Medicine, St. Louis; F. Perry Wilson, MD, Associate Professor, Medicine, Yale School of Medicine, New Haven, Connecticut; Journal of the American Society of Nephrology, online September 1, 2021
WebMD news from HealthDay
Copyright © 2013-2020 Health Day. All rights reserved.
Comments are closed.