Lash, James P.

Abstract RATIONALE: Chronic kidney disease (CKD) is common in the general population and is associated with inflammation and compromised immune function. Since these mechanisms are hypothesized to promote severe COVID-19, we tested associations of pre-pandemic CKD with incident COVID-19 hospitalization or death in a large, multi-ethnic, US general population-based meta-cohort of adults. METHODS: Data were harmonized and pooled from 9 NIH-funded longitudinal cohorts participating in the Collaborative Cohort of Cohorts for COVID-19 Research (C4R). CKD was classified by KDIGO 2024 CKD guideline (Low Risk, Moderately Increased Risk, High Risk, Very High Risk) using pre-pandemic urinary albumin-to-creatinine ratio (uACR) and estimated glomerular filtration rate using creatinine (eGFRcr). Incident COVID-19 hospitalization or death was ascertained over 2020−2023 via self-report and active surveillance, with medical record adjudication in a subset. In our primary analysis, we assessed associations between CKD stages and incident COVID-19 hospitalization or death. A secondary analysis examined joint association of CKD stages and the number of comorbidities (obesity, hypertension, diabetes, and cardiovascular disease) with the severe COVID-19. Multivariable hazard ratios (HRs) were estimated by cause-specific Cox regression, adjusting for socio-demographics and smoking. RESULTS: Among 26,039 multi-ethnic adult participants (mean age 66.1±14.8, 60.6 % female, 28.6% Whites, 3.2% Asians, 20.6% Blacks, 41.3% Hispanics, 6.3% American Indians) with a median follow-up of 550 days since the onset of the pandemic (baseline: March 1, 2020), there were 734 incident COVID-19 hospitalizations or deaths. The mean time since CKD markers were measured before the baseline was 6.5 years. The cumulative incidence of severe COVID-19 was 2.3, 3.5, 6.5, and 7.3% across CKD risk stages, and similar patterns were observed within variant types (Figure 1). Compared to participants with Low Risk of CKD, there was a graded increased hazards of severe COVID-19 across CKD stages, with HRs (95% CIs) of 1.27 (1.03−1.55) for Moderately Increased Risk, 2.33 (1.77−3.06) for High Risk, and 2.72 (1.89−3.92) for Very High Risk. In a joint analysis, both increased CKD risk and a higher number of comorbidities were associated with a higher risk of severe COVID-19, showing the highest HR of 12.29 (5.75−26.27) in Very High Risk individuals with four comorbidities compared to Low Risk individuals with none. CONCLUSIONS: Higher CKD stages were associated with a greater risk of COVID-19 hospitalization or death and the risk is substantially heightened with additional comorbidities. These results suggest that adults with CKD and related comorbidities may merit enhanced COVID-19 risk mitigation.