COVID-19 infection and the progression of kidney disease in British Columbia, Canada.

Abstract

Background: We investigated the long-term effect of COVID-19 on eGFR trajectory and the association with progression to kidney failure in patients with CKD.

Methods: Patients living with non-dialysis dependent CKD from British Columbia, Canada infected with COVID-19 (cases) were matched 1:2 to non-COVID-19 infected controls on variables including pre-COVID-19 annual rate of eGFR decline. Patients were followed from 90 days from the date of COVID-19 diagnosis. The Cox proportional hazards model was used for the primary outcome of kidney failure defined as a composite of eGFR reaching <15 ml/min/1.73m2, initiation of maintenance dialysis, or kidney transplantation. A linear mixed regression model was used to calculate the annual rate of change in eGFR.

Results: The study included 802 patients, 268 cases and 534 controls. Median age was 70 years and 54% were male. Over ∼3 years of follow up, the risk of developing kidney failure did not differ significantly between cases and controls. The annual rate of eGFR decline was -2.05 ml/min/1.73m2 among cases versus -1.35 ml/min/1.73m2 among controls representing a rate difference of 0.71 ml/min/1.73m2 (p-value= 0.02).

Conclusion: In patients with non-dialysis dependent CKD who survived at least 90 days without requiring dialysis, COVID-19 was not associated with an increased long-term risk of kidney failure over three years, but was associated with a greater annual decline in eGFR. Future research with longer follow-up is required to examine if this difference persists and leads to increased risk for kidney failure.