Association of PM 2.5 components with the incidence of end-stage kidney disease in two large European cohorts

Abstract

Background and aim: End-stage kidney disease (ESKD) poses a high burden on patients and the health system. The very few studies on air pollution and ESKD have shown associations with PM₂.₅, but no study so far has investigated which of the components may be most relevant. We investigate the association of long-term exposure to PM₂.₅ elements with ESKD incidence in two large population-based European cohorts. Methods: Individuals in the Rome Longitudinal Study (RoLS) and the Vorarlberg Health Monitoring and Prevention Program (VHM&PP) were followed up with Dialysis and Transplant Registries from 1985 to 2019 and 2011 to 2019, respectively. Long-term exposures to eight PM₂.₅ components (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) at residence were estimated with Europe-wide hybrid land use regression models at 100x100m scale. Hazard ratios (HR) were determined from Cox-proportional hazard models with age as time axis and adjusted for individual and neighbourhood confounders. Results: RoLS contributed 3,231 cases from 1,939,461 individuals (mean age 52.4 years; crude incidence rate (CIR) 0.22 per 1000 person years) and VHM&PP 501 cases from 136,823 individuals (mean age 42.1years; CIR 0.14). In RoLS, elements associated with ESKD were potassium (HR 1.25 [1.05,1.48]) and sulphur (HR 1.10 [0.97,1.25]) for an increase of 50 and 200 ng/m³, respectively, whereas in VHM&PP, risk of ESKD was associated with copper (HR 1.20 [0.97, 1.47]) and iron (1.30 [0.98, 1.74]) for 5 and 100 ng/m³, respectively . Conclusion: Air pollution indicative for biomass burning (potassium) and long-range transport (sulphur) in Rome, and indicators of traffic-related air pollution (iron and copper) in Vorarlberg were associated with an increased risk of ESKD.