Increased vulnerability to COVID‐19 in chronic kidney disease

• Published in: Journal of internal medicine Vol. 290; no. 1; pp. 166 - 178
• Main Authors: Carlson, N., Nelveg‐Kristensen, K.‐E., Freese Ballegaard, E., Feldt‐Rasmussen, B., Hornum, M., Kamper, A.‐Lise, Gislason, G., Torp‐Pedersen, C.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-07-2021; John Wiley and Sons Inc
• Subjects: COVID-19; Diabetes mellitus; Epidermal growth factor receptors; estimated glomerular filtration rate; Glomerular filtration rate; Health risks; Hypertension; Kidney diseases; Kidneys; Original; Regression analysis; Regression models; Renal function; Renal insufficiency; Risk analysis; Risk factors; Strata; COVID-19; estimated glomerular filtration rate; renal insufficiency
• ISSN: 0954-6820; 1365-2796
• DOI: 10.1111/joim.13239

Background
The significance of chronic kidney disease on susceptibility to COVID‐19 and subsequent outcomes remains unaddressed.
Objective
To investigate the association of estimated glomerular filtration rate (eGFR) on risk of contracting COVID‐19 and subsequent adverse outcomes.
Methods
Rates of hospital‐diagnosed COVID‐19 were compared across strata of eGFR based on conditional logistic regression using a nested case–control framework with 1:4 matching of patients diagnosed with COVID‐19 with controls from the Danish general population on age, gender, diabetes and hypertension. Risk of subsequent severe COVID‐19 or death was assessed in a cohort study with comparisons across strata of eGFR based on adjusted Cox regression models with G‐computation of results to determine 60‐day risk standardized to the distribution of risk factors in the sample.
Results
Estimated glomerular filtration rate was inversely associated with rate of hospital‐diagnosed COVID‐19: eGFR 61–90 mL/min/1.73m2 HR 1.13 (95% CI 1.03–1.25), P = 0.011; eGFR 46–60 mL/min/1.73m2  HR 1.26 (95% CI 1.06–1.50), P = 0.008; eGFR 31–45 mL/min/1.73m2 HR 1.68 (95% CI 1.34–2.11), P < 0.001; and eGFR ≤ 30 mL/min/1.73m2 3.33 (95% CI 2.50–4.42), P < 0.001 (eGFR > 90 mL/min/1.73m2 as reference), and renal impairment was associated with progressive increase in standardized 60‐day risk of death or severe COVID‐19; eGFR > 90 mL/min/1.73m2 13.9% (95% CI 9.7–15.0); eGFR 90–61 mL/min/1.73m2 16.1% (95% CI 14.5–17.7); eGFR 46–60 mL/min/1.73m2 17.8% (95% CI 14.7–21.2); eGFR 31–45 mL/min/1.73m2 22.6% (95% CI 18.2–26.2); and eGFR ≤ 30 mL/min/1.73m2 23.6% (95% CI 18.1–29.1).
Conclusions
Renal insufficiency was associated with progressive increase in both rate of hospital‐diagnosed COVID‐19 and subsequent risk of adverse outcomes. Results underscore a possible vulnerability associated with impaired renal function in relation to COVID‐19.