Kidney Function Decline After COVID-19 Infection

The association between COVID-19 and long-term kidney function is not well understood, although it is known that COVID-19 is associated with acute kidney injury. To address this gap, Viyaasan Mahalingasivam, MPhil, and colleagues conducted a cohort study examining whether kidney function decline hastened after COVID-19 infection compared with after other respiratory tract infections.

Their study used data from the Stockholm Creatinine Measurements Project in Stockholm, Sweden, between February 1, 2018, and January 1, 2022. Statistical analyses took place between June 2023 and October 2024. Participants comprised hospitalized and nonhospitalized adults with at least one estimated glomerular filtration rate (eGFR) measurement in the 2 years before receiving a positive COVID-19 test result or pneumonia diagnosis. Outcomes included mean annual change in eGFR after COVID-19 and after pneumonia, which was calculated using a linear regression model.

A total of 134,565 patients were included in the COVID-19 cohort. Their median (IQR) age was 51 (37-64) years and 74,819 (55.6%) were women. The pneumonia cohort comprised 35,987 patients; their median (IQR) age was 71 (56-81) years and 19,359 (53.8%) were women. Median (IQR) baseline eGFR was 94 (79-107) mL/min/1.73 m² for the COVID-19 group and 79 (61-92) mL/min/1.73 m² for the pneumonia group.

Both COVID-19 and pneumonia infections were associated with annual decline in eGFR, after adjusting for covariates. The decline was greater after COVID-19 infection (3.4%; 95% CI, 3.2%-3.5%) than after pneumonia infection (2.3%; 95% CI, 2.1%-2.5%). The decline in kidney function was more severe among patients who were hospitalized for COVID-19 (5.4%; 95% CI, 5.2%-5.6%). However, hospitalization did not demonstrate a similar effect among patients hospitalized for pneumonia.

In summary, the study demonstrated an association between COVID-19 and an acceleration in kidney function decline compared with pneumonia. The decline was particularly severe after hospitalization, suggesting that patients hospitalized for COVID-19 should be monitored closely for kidney function. This will help ensure early diagnosis and optimal management of CKD to prevent complications and further decline in kidney function.

Source: JAMA Network Open