Filenews 4 September 2021
Kidney damage that can lead to a chronic condition even end-stage, can be caused by coronavirus disease, even in those who have had very mild symptoms, a newer study now finds.
This complication is now added to the list of effects of long-term covid, and gives the signal to those who have recovered to be tested for the health of their kidneys, since usually their dysfunction does not give pain or other symptoms. And while the problem can be reversible if detected in a timely manner, a possible delay can lead to serious damage.
Researchers at the University of Washington School of Medicine in St. Louis and the Veterans Care System of Sant Louis, found in a study published in the scientific journal of the American Society of Nephrology, that those hospitalized in ICU have a higher chance of developing kidney damage due to coronavirus, however, relevant cases have been observed in patients who had mild symptoms.
According to international epidemiological data, 90% of people with kidney problems are unaware of their condition.
The study's lead author, assistant professor of medicine at the University of Washington and director of the Center for Clinical Epidemiology of the St. Louis Veterans Care System, Ziad Al Ali, pointed out that "If renal function control is not an integral part of the strategy in post-COVID care, then we will not be able to help hundreds of thousands of people who have no idea that their kidney function has decreased due to this virus ». Referring to the increase in infections with the Delta variant, the professor estimated that over half a million patients suffered an infection of his renal function due to the coronavirus.
The investigation
The researchers analyzed data for over 1.7 million people. veterans for the period from 1.3.2020 – 15.3.2021. Of these, COVID-19 infections had been confirmed in 89,216 people, mostly men over the age of 60, who overcame the disease. At the same time, they analyzed data for 151,289 adult women, of whom 8,817 with COVID-19.
Of the COVID-19 patients, 12,376 (13.9%) required hospitalization and of these, 4,146 (4.6%) had been admitted to intensive care units (ICU).
"The risk of impaired renal function is higher in people who needed ICU. However, the risk extends to all patients, even those who had milder symptoms of the disease," said Professor Al Ali, stressing that the early stages of kidney disease can often be treated with medication.
He added that "It is necessary to discover kidney dysfunction with blood tests, before the problem progresses and becomes more difficult to treat. It is particularly important to check it up early, otherwise, we will miss many people and, unfortunately, we will face more advanced kidney diseases along the way."
The chances of damage
Comparing those who became mildly ill and did not require hospitalization with people who did not contract the virus, the former had a 15% higher risk of suffering kidney disease, a 30% higher risk of acute kidney damage, and a 215% higher risk of developing end-stage kidney disease. The latter occurs when the kidneys can no longer effectively remove waste from the body. In such cases, hemodialysis or kidney transplantation is required to keep patients alive.
The risk was increased for patients who needed hospitalization, especially for those hospitalized in ICU, by 7 times more for the development of a serious case of renal function, 8 times for acute kidney damage and 13 times for end-stage renal disease.
"People who were hospitalized or needed ICU care are at the highest risk," Al Ali said. "But the risk is not zero for those who have had milder cases. In fact, it's important. And we must remember that we do not yet know the health effects for those suffering from long COVID in the coming years."
According to the study, after the first 30 days of COVID-19 infection, 4,757 patients (5.3%) experienced a decrease of at least 30% in glomerular filtration (GFR) rates, which doctors use to assess kidney function and, where appropriate, determine the severity of kidney disease. The rate is determined by a simple blood test that measures creatinine levels, a waste product in the blood that is filtered by the kidneys and discarded into the urine.
The researchers found that people who had milder cases of COVID-19 had a 1.09 times greater risk of reducing GFR by 30% or more. For hospitalized COVID-19 patients outside of intensive care, the risk was twice as high for a 30% or more GFR reduction, while intensive care unit patients had a three-fold risk of suffering an estimated drop in GFR of 30% or more.
"Kidney damage goes beyond the decreased function caused by normal aging," Al Ali explained. "The renal function of a 60-year-old is less powerful than a 20-year-old. The drop in renal function that we observed in these patients is not a normal aging. It's definitely a disease condition.
