COVID-19 Takes a Greater Toll on Kidneys Than Pneumonia

TOPLINE:

COVID-19 survivors show a more pronounced decline in kidney function than those who recover from pneumonia caused by other infections. This decline in kidney function, measured by the estimated glomerular filtration rate (eGFR), is particularly steep among individuals who require hospitalization for COVID-19.

METHODOLOGY:

• SARS-CoV-2, the virus that causes COVID-19, has been associated with acute kidney injury, but its potential impact on long-term kidney function remains unclear.
• Researchers investigated the decline in kidney function after COVID-19 vs pneumonia by including all hospitalized and nonhospitalized adults from the Stockholm Creatinine Measurements Project who had at least one eGFR measurement in the 2 years before a positive COVID-19 test result or pneumonia diagnosis.
• Overall, 134,565 individuals (median age, 51 years; 55.6% women) who had their first SARS-CoV-2 infection between February 2020 and January 2022 were included, of whom 13.3% required hospitalization within 28 days of their first positive COVID-19 test result.
• They were compared with 35,987 patients (median age, 71 years; 53.8% women) who were diagnosed with pneumonia between February 2018 and January 2020; 46.5% of them required hospitalization.
• The primary outcome measure focused on the mean annual change in eGFR slopes before and after each infection; the secondary outcome assessed was the annual change in postinfection eGFR slopes between COVID-19 and pneumonia cases.

TAKEAWAY:

• Before COVID-19, eGFR changes were minimal, but after the infection, the average decline increased to 4.1 (95% CI, 3.8-4.4) mL/min/1.73 m²; however, in the pneumonia cohort, a decline in eGFR was noted both before and after the infection.
• After COVID-19, the mean annual decline in eGFR was 3.4% (95% CI, 3.2%-3.5%), increasing to 5.4% (95% CI, 5.2%-5.6%) for those who were hospitalized.
• In contrast, the pneumonia group experienced an average annual decline of 2.3% (95% CI, 2.1%-2.5%) after the infection, which remained unchanged when analyzing only patients who were hospitalized.
• The risk for a 25% reduction in eGFR was higher in patients with COVID-19 than in those with pneumonia (hazard ratio [HR], 1.19; 95% CI, 1.07-1.34), with the risk being even higher among those who required hospitalization (HR, 1.42; 95% CI, 1.22-1.64).

IN PRACTICE:

“These findings help inform decisions regarding the need to monitor kidney function in survivors of COVID-19 and could have implications for policymakers regarding future healthcare planning and kidney service provision,” the authors wrote.

SOURCE:

This study was led by Viyaasan Mahalingasivam, MPhil, London School of Hygiene & Tropical Medicine, London, England. It was published online in JAMA Network Open.

LIMITATIONS:

This study lacked information on important confounders such as ethnicity and body mass index. The follow-up period was not long enough to fully evaluate the long-term association of COVID-19 with kidney function. Additionally, some individuals may have been misclassified as nonhospitalized if their first infection was mild and a subsequent infection required hospitalization.

DISCLOSURES:

This study was supported by grants from the National Institute for Health and Care Research, Njurfonden, Stig and Gunborg Westman Foundation, and the Swedish Research Council. One author reported receiving a Career Development Award from the National Institute for Health and Care Research, and another author reported receiving grants from Njurfonden, Stig and Gunborg Westman Foundation, Swedish Research Council, Swedish Heart Lung Foundation, and Region Stockholm during the conduct of the study.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.