Association of air pollution with incidence of end-stage kidney disease in two large European cohorts

End-stage kidney disease (ESKD) poses a high burden on patients and health systems. While numerous studies indicate an association between air pollution and chronic kidney disease, studies on ESKD are rare. We investigated the association of long-term exposure to nitrogen dioxide (NO₂), fine particulate matter (PM_2.5), black carbon (BC) and ozone (O₃) with ESKD incidence in two large population-based European cohorts. We followed individuals in the Austrian Vorarlberg Health Monitoring and Promotion Program (VHM&PP) and the Italian Rome Longitudinal Study (RoLS) using dialysis and kidney transplant registries. Long-term exposure to pollutants was estimated at the home address using Europe-wide land use regression models at 100x100m scale. Hazard ratios (HR) were determined from Cox-proportional hazard models adjusted for individual and neighbourhood level confounders. We observed 501 events among 136,823 individuals in VHM&PP (mean age 42.1 years; crude incidence rate (IR) 0.14 per 1000 person-years) and 3231 events among 1,939,461 individuals in RoLS (mean age 52.4 years; IR 0.22 per 1000 person-years). In VHM&PP, there was no evidence of an association between PM_2.5 or O₃ and ESKD. There were elevated HRs but with large confidence intervals for BC (HR 1.17 [95 % confidence interval (CI): 0.98, 1.39] for 0.5*10⁻⁵/m), and for NO₂ (HR 1.14 [95%CI: 0.96, 1.35] for 10 μg/m³). In RoLS, ESKD was associated with PM_2.5 (HR 1.37 [95 % CI: 1.06, 1.76] for an increase of 5 μg/m³), while there was no evidence of association with BC, NO₂, or O₃ exposure. Our study suggests an association of air pollution with ESKD incidence, which differed between the two cohorts and may possibly be influenced by respective air pollution mixtures.