A recent study suggests that Covid-19 survivors show an increased risk of kidney problems, including lifelong reduction of kidney function in some patients.
The one year study of over 1.6 million U.S. Veterans was published in the Journal of the American Society of Nephrology. They found that the sicker the Covid-19 patients were initially, the more likely they were to experience lingering kidney damage.
The study shows a significant difference between the non-Covid group vs Covid-19 patients in their eGFR up to one year.
eGFR is the estimated glomerular filtration rate, which is currently the best test to measure your level of kidney function and determine your stage of kidney disease.
"You see, really, across the board, a higher risk of a bunch of important kidney-associated events," said Dr F. Perry Wilson, a nephrologist and associate professor of medicine at Yale, said to NYTimes. "What was particularly striking to me was that these persisted." Dr F. Perry Wilson was not involved in the study.
Between one and six months after being infected, the Covid-19 survivors have a 35 per cent chance to have kidney damage or substantial declines in kidney function than those who did not, said Dr Ziyad Al-Aly, chief of the research and development services at the V.A. St. Louis Health Care System and senior author of the study.
Generally, healthy adults gradually lose their kidney function about 1 per cent a year starting from their 30s.
4,757 of the Covid-19 survivors had lost at least 30 per cent of their kidney function in the year after their infection, which is approximately 30 years of kidney function decline.
This study shows the importance of post-care for these Covid-19 patients and the need to include kidney function and disease. This is because many people with reduced kidney function do not exhibit any pain or symptoms.
It is to note that the study is done on largely white males with a median age of 68. It is unclear how generalisable the results are.
“However, there’s a pretty notable impact on kidney health in survivors of Covid-19 over the long term, particularly those who were very sick during their acute illness,” said Dr C. John Sperati, a nephrologist and associate professor of medicine at Johns Hopkins. Dr C. John was not involved in the study.
It is unclear why Covid-19 can cause kidney damage.
Covid-19 patients in the hospital seemed to have a greater need for dialysis and more protein and blood in their urine than other patients hospitalised with other severe illnesses, said Dr C. John Sepati.
To read about the study, click here.