Association between long-term exposure to low level air pollutants and incident end-stage kidney disease in the UK Biobank: A prospective cohort

Abstract

BackgroundPrevious studies suggest that air pollution can increase the risk of incident chronic kidney disease (CKD). However, the association between end-stage kidney disease (ESKD) and co-exposure to relatively low-level air pollutants remains unclear. MethodsA prospective cohort was designed based on UK Biobank. From 1 January 2010 to 12 November 2021, 453,347 participants were followed up over a median of 11.87 years. Principal component analysis was used to identify major patterns of five air pollutants, including PM2.5, PM2.5-10, PM10, NO2, and NOx. Sub-distribution hazards models were used to estimate the associations between air pollution, individually or jointly, and incident ESKD, CKD, and all-cause death, respectively. ResultsPrincipal component analysis identified two principal components, namely RC1 (PM2.5, NO2, and NOx) and RC2 (PM2.5-10 and PM10). An elevated risk of incident ESKD was associated with an interquartile range (IQR) increase in PM2.5 (hazard ratio: 1.11, 95% confidence interval: 1.02–1.22), NO2 (1.16, 1.04–1.30), NOx (1.08, 1.00–1.17), and RC1 (1.12, 1.02–1.23). An elevated risk of incident CKD was associated with an IQR increase in PM2.5 (1.05, 1.03–1.07), NO2 (1.04, 1.02–1.06), NOx (1.03, 1.02–1.05), and RC1 (1.04, 1.02–1.06). An increased risk of all-cause mortality was associated with an IQR increase in PM2.5 (1.02, 1.00–1.04). Restricted cubic spline analyses indicated a monotonic elevating association of PM2.5, NO2, NOx, and RC1 with ESKD incidence. ConclusionsLong-term exposure to PM2.5, NO2, NOx, and their complex was associated with elevated ESKD incidence, even at relatively lower levels of air pollution.