Another Hidden Covid Risk: Lingering Kidney Problems

September 1, 2021in News

Since the beginning of the pandemic, doctors have found that people who become very ill with Covid-19 often experience kidney problems, not just the lung impairments that are the hallmark of the illness.

Now, a large study suggests that kidney issues can last for months after patients recover from the initial infection, and may lead to a serious lifelong reduction of kidney function in some patients.

The study, published Wednesday in the Journal of the American Society of Nephrology, found that the sicker Covid patients were initially, the more likely they were to experience lingering kidney damage.

But even people with less severe initial infections could be vulnerable.

“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, who was not involved in the study. “And what was particularly striking to me was that these persisted.”

Kidneys play a vital role in the body, clearing toxins and excess fluid from the blood, helping maintain a healthy blood pressure, and keeping a balance of electrolytes and other important substances. When the kidneys are not working properly or efficiently, fluids build up, leading to swelling, high blood pressure, weakened bones and other problems.

The heart, lungs, central nervous system and immune system can become impaired. In end-stage kidney disease, dialysis or an organ transplant may become necessary. The condition can be fatal.

The new study, based on records of patients in the Department of Veterans Affairs health system, analyzed data from 89,216 people who tested positive for the coronavirus between March 1, 2020, and March 15, 2021, as well as data from 1,637,467 people who were not Covid patients.

Between one and six months after becoming infected, Covid survivors were about 35 percent more likely than non-Covid patients to have kidney damage or substantial declines in kidney function, said Dr. Ziyad Al-Aly, chief of the research and development service at the V.A. St. Louis Health Care System and senior author of the study.

“People who have survived the first 30 days of Covid are at risk of developing kidney disease,” Dr. Al-Aly, a nephrologist, said.

Because many people with reduced kidney function do not experience pain or other symptoms, “what’s really important is that people realize that the risk is there and that physicians caring for post-Covid patients really pay attention to kidney function and disease,” he said.

The two sets of patients in the study differed, in that members of one group had all been infected with Covid and members of the other group may have had a variety of other health conditions. Experts cautioned that there were limitations to the comparisons.

The researchers tried to minimize the differences with detailed analyses that adjusted for a long list of demographic characteristics, pre-existing health conditions, medication usage and whether people were in nursing homes.

Another limitation is that patients in the V.A. study were largely male and white, with a median age of 68, so it is unclear how generalizable the results are.

One strength of the research, experts said, is that it involves over 1.7 million patients with detailed electronic medical records, making it the largest study so far on Covid-related kidney problems.

While the results most likely would not apply to all Covid patients, they show that for those in the study, “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, who was not involved in the study.

Other researchers have found similar patterns, “so this is not the only study suggesting that these events are transpiring after Covid-19 infection,” he added.

He and other experts said that if even a small percentage of the millions of Covid survivors in the United States developed lasting kidney problems, the impact on health care would be great.

To assess kidney function, the research team evaluated levels of creatinine, a waste product that kidneys are supposed to clear from the body, as well as a measure of how well the kidneys filter the blood called the estimated glomerular filtration rate.

Healthy adults gradually lose kidney function over time, about 1 percent or less a year, starting in their 30s or 40s, Dr. Wilson said. Serious illnesses and infections can cause more profound or permanent loss of function that may lead to chronic kidney disease or end-stage kidney disease.

The new study found that 4,757 Covid survivors had lost at least 30 percent of kidney function in the year after their infection, Dr. Al-Aly said.

That is equivalent to roughly “30 years of kidney function decline,” Dr. Wilson said.

Covid patients were 25 percent more likely to reach that level of decline than people who had not had the illness, the study found.

Smaller numbers of Covid survivors had steeper declines. But Covid patients were 44 percent more likely than non-Covid patients to lose at least 40 percent of kidney function and 62 percent more likely to lose at least 50 percent.

End-stage kidney disease, which occurs when at least 85 percent of kidney function is lost, was detected in 220 Covid patients, Dr. Al-Aly said. Covid survivors were nearly three times as likely to receive the diagnosis as patients without Covid, the study found.

Dr. Al-Aly and his colleagues also looked at a type of sudden renal failure called acute kidney injury, which other studies have found in up to half of hospitalized Covid patients. The condition can heal without causing long-term loss of kidney function.

But the V.A. study found that months after their infection, 2,812 Covid survivors suffered acute kidney injury, nearly twice the rate in non-Covid patients, Dr. Al-Aly said.

Dr. Wilson said the new data supported results of a study of 1,612 patients that he and colleagues conducted that found that Covid patients with acute kidney injury had significantly worse kidney function in the months after leaving the hospital than people with acute kidney injuries from other medical conditions.

In the new study, researchers did not directly compare Covid survivors with people infected with other viruses, like the flu, making it hard to know “are you really any sicker than if you just had another bad infection,” Dr. Sperati said.

In a previous study by Dr. Al-Aly’s team, however, which looked at many post-Covid health issues, including kidney problems, people hospitalized with Covid-19 were at significantly greater risk of developing long-term health problems in virtually every medical category, including cardiovascular, metabolic and gastrointestinal conditions, than were people hospitalized with the flu.

Every type of kidney impairment measured in the new study was much more common in Covid patients who were sicker initially — those in intensive care or who experienced acute kidney injury in the hospital.

People who were less ill during their Covid hospitalization were less likely to have lingering kidney problems, but still considerably more likely than non-Covid patients.

“People who are at highest risk are the people who really had it bad to start with,” Dr. Al-Aly said. “But really, no one is spared the risk.”

The study also found that even Covid patients who never needed hospitalization had slightly higher risk of kidney trouble than the general V.A. patient population. But the risk seemed so small, Dr. Sperati said, that “I don’t know that I would hang my hat on” those results.

Dr. Wilson noted that some Covid patients who did not need hospitalization were nonetheless quite ill, needing to stay in bed for days. He said it’s possible that those were the ones who developed long-term kidney dysfunction, rather than people at the mildest end of the Covid spectrum.

Doctors are unsure why Covid can cause kidney damage. Kidneys might be especially sensitive to surges of inflammation or immune system activation, or blood-clotting problems often seen in Covid patients may disturb kidney function, experts said.

Dr. Sperati said Covid patients in the hospital seemed to have greater need for dialysis, and more protein and blood in their urine, than patients hospitalized with other severe illnesses.

“Covid is probably a little more of a kidney-toxic virus,” Dr. Wilson said. “I do think that the Covid syndrome has some long-term adverse effects on the kidney.”

The post Another Hidden Covid Risk: Lingering Kidney Problems appeared first on New York Times.

Neurology and neuropsychiatry of COVID-19: a systematic review and meta-analysis of the early literature reveals frequent CNS manifestations and key emerging narratives


  1. Jonathan P Rogers1,2, Cameron J Watson3,


There is accumulating evidence of the neurological and neuropsychiatric features of infection with SARS-CoV-2. In this systematic review and meta-analysis, we aimed to describe the characteristics of the early literature and estimate point prevalences for neurological and neuropsychiatric manifestations.

We searched MEDLINE, Embase, PsycINFO and CINAHL up to 18 July 2020 for randomised controlled trials, cohort studies, case-control studies, cross-sectional studies and case series. Studies reporting prevalences of neurological or neuropsychiatric symptoms were synthesised into meta-analyses to estimate pooled prevalence.

13 292 records were screened by at least two authors to identify 215 included studies, of which there were 37 cohort studies, 15 case-control studies, 80 cross-sectional studies and 83 case series from 30 countries. 147 studies were included in the meta-analysis. The symptoms with the highest prevalence were anosmia (43.1% (95% CI 35.2% to 51.3%), n=15 975, 63 studies), weakness (40.0% (95% CI 27.9% to 53.5%), n=221, 3 studies), fatigue (37.8% (95% CI 31.6% to 44.4%), n=21 101, 67 studies), dysgeusia (37.2% (95% CI 29.8% to 45.3%), n=13 686, 52 studies), myalgia (25.1% (95% CI 19.8% to 31.3%), n=66 268, 76 studies), depression (23.0% (95% CI 11.8% to 40.2%), n=43 128, 10 studies), headache (20.7% (95% CI 16.1% to 26.1%), n=64 613, 84 studies), anxiety (15.9% (5.6% to 37.7%), n=42 566, 9 studies) and altered mental status (8.2% (95% CI 4.4% to 14.8%), n=49 326, 19 studies). Heterogeneity for most clinical manifestations was high.

Neurological and neuropsychiatric symptoms of COVID-19 in the pandemic’s early phase are varied and common. The neurological and psychiatric academic communities should develop systems to facilitate high-quality methodologies, including more rapid examination of the longitudinal course of neuropsychiatric complications of newly emerging diseases and their relationship to neuroimaging and inflammatory biomarkers.

This article is made freely available for use in accordance with BMJ’s website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose (including text and data mining) provided that all copyright notices and trade marks are retained.

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Age-Adjusted Associations Between Comorbidity and Outcomes of COVID-19: A Review of the Evidence From the Early Stages of the Pandemic

Authors: Kate E. Mason*Gillian MaudsleyPhilip McHaleAndy PenningtonJennifer Day and Ben Barr

Objectives: Early in the COVID-19 pandemic, people with underlying comorbidities were overrepresented in hospitalised cases of COVID-19, but the relationship between comorbidity and COVID-19 outcomes was complicated by potential confounding by age. This review therefore sought to characterise the international evidence base available in the early stages of the pandemic on the association between comorbidities and progression to severe disease, critical care, or death, after accounting for age, among hospitalised patients with COVID-19.

Methods: We conducted a rapid, comprehensive review of the literature (to 14 May 2020), to assess the international evidence on the age-adjusted association between comorbidities and severe COVID-19 progression or death, among hospitalised COVID-19 patients – the only population for whom studies were available at that time.

Results: After screening 1,100 studies, we identified 14 eligible for inclusion. Overall, evidence for obesity and cancer increasing risk of severe disease or death was most consistent. Most studies found that having at least one of obesity, diabetes mellitus, hypertension, heart disease, cancer, or chronic lung disease was significantly associated with worse outcomes following hospitalisation. Associations were more consistent for mortality than other outcomes. Increasing numbers of comorbidities and obesity both showed a dose-response relationship. Quality and reporting were suboptimal in these rapidly conducted studies, and there was a clear need for additional studies using population-based samples.

Conclusions: This review summarizes the most robust evidence on this topic that was available in the first few months of the pandemic. It was clear at this early stage that COVID-19 would go on to exacerbate existing health inequalities unless actions were taken to reduce pre-existing vulnerabilities and target control measures to protect groups with chronic health conditions.

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The Age-Related Risk of Severe Outcomes Due to COVID-19 Infection: A Rapid Review, Meta-Analysis, and Meta-Regression

Authors: Karla Romero Starke 1Gabriela Petereit-Haack 2Melanie Schubert 1Daniel Kämpf 1Alexandra Schliebner 1Janice Hegewald 1Andreas Seidler 1


Increased age appears to be a strong risk factor for COVID-19 severe outcomes. However, studies do not sufficiently consider the age-dependency of other important factors influencing the course of disease. The aim of this review was to quantify the isolated effect of age on severe COVID-19 outcomes. We searched Pubmed to find relevant studies published in 2020. Two independent reviewers evaluated them using predefined inclusion and exclusion criteria. We extracted the results and assessed seven domains of bias for each study. After adjusting for important age-related risk factors, the isolated effect of age was estimated using meta-regression. Twelve studies met our inclusion criteria: four studies for COVID-19 disease severity, seven for mortality, and one for admission to ICU. The crude effect of age (5.2% and 13.4% higher risk of disease severity and death per age year, respectively) substantially decreased when adjusting for important age-dependent risk factors (diabetes, hypertension, coronary heart disease/cerebrovascular disease, compromised immunity, previous respiratory disease, renal disease). Adjusting for all six comorbidities indicates a 2.7% risk increase for disease severity (two studies), and no additional risk of death per year of age (five studies). The indication of a rather weak influence of age on COVID-19 disease severity after adjustment for important age-dependent risk factors should be taken in consideration when implementing age-related preventative measures (e.g., age-dependent work restrictions).

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