Acute kidney injury (AKI) occurs in up to half of patients hospitalized with COVID-19 and up to three-quarters of patients with COVID-19 in the intensive care unit. Now a new study finds that kidney function declines faster in patients infected with SARS-CoV-2, the novel coronavirus that causes COVID-19, after discharge.

Investigators compared 182 patients with COVID-19-associated AKI and 1430 patients with AKI and a negative SARS-CoV-2 test who were hospitalized during March 10 to August 31, 2020. The median age of the cohort was 69.7 years, and half were women. AKI was based on creatinine criteria only (not urine output).

Patients with COVID-19-associated AKI experienced greater decreases in estimated glomerular filtration rate (eGFR) than patients with unrelated AKI after discharge independent of demographics, comorbidities, and AKI severity, Francis Perry Wilson, MD, MSCE, of Yale University School of Medicine in New Haven, CT, and colleagues reported in JAMA Network Open. In a fully adjusted model, the mean eGFR declined by 16.7 mL/min/1.73 m2 per year in the COVID-19 group and by 2.7 mL/min/1.73 m2 per year in the group without COVID-19, a significant difference in mean eGFR slope of -14.0 mL/min/1.73 m2 per year,

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Further, a subgroup analysis of 319 patients who had not recovered baseline kidney function at hospital discharge showed that those with COVID-19-associated AKI had a significant 43% lower likelihood of kidney recovery (ie, a serum creatinine less than 1.5 times the baseline level) during outpatient follow-up than those with unrelated AKI.

“The new findings suggest that patients recovering from COVID-19-associated acute kidney injury require monitoring of kidney function following hospital discharge,” Dr Wilson and his coauthors wrote.

Patients infected with the coronavirus were more likely to be Black (40.1% vs 15.7%) or Hispanic (22% vs 8.8%). They also had a lower comorbidity score but similar prevalence of chronic kidney disease (33% vs 35%) and hypertension (89.0% vs 88.6%). Patients with COVID-19-associated AKI had significantly higher proteinuria on admission (33.5% vs 18.9%), greater dialysis requirement (3.8% vs 1.2%), longer duration of in-hospital AKI (median 1.3 vs 1.1 days), and longer hospital stay (median 14.1 vs 6.9 days). Significantly more patients with COVID-19 required a ventilator (28.6% vs 11.6%) and vasopressors (26.9% vs 18.3%).

“Compared with patients without COVID-19, those with COVID-19 develop more severe AKI, have greater dialysis requirements, and experience less in-hospital kidney recovery, which may increase their risk for incident chronic kidney disease (CKD) or progression of existing CKD,” Dr Wilson’s team wrote.

Additional and longer-term studies are needed.

“Identifying predictors of longitudinal eGFR decrease in patients with COVID-19-associated AKI may help prioritize which patients need close outpatient follow-up during the pandemic,” the investigators concluded. It also has important public health implications for resource allocation, screening, and patient counseling.


Nugent J, Aklilu A, Yamamoto Y, et al. Assessment of acute kidney injury and longitudinal kidney function after hospital discharge among patients with and without COVID-19. Published online March 10, 2021. JAMA Netw Open. 2021;4(3):e211095. doi:10.1001/jamanetworkopen.2021.1095