Long-Term Exposure to Ambient Fine Particulate Matter and Chronic Kidney Disease: A Cohort Study

BACKGROUND: Chronic kidney disease (CKD) is a serious global public health challenge, but there is limited information on the connection between air pollution and risk of CKD. OBJECTIVE: The aim of this study was to investigate the association between long-term exposure to particulate matter (PM) with an aerodynamic diameter of less than 2.5 mu m (PM2.5) and the development of CKD in a large cohort. METHODS: A total of 100,629 nonCKD Taiwanese residents age 20 y or above were included in this study between 2001 and 2014. Ambient PM2.5 concentration was estimated at each participant's address using a satellite-based spatiotemporal model. Incident CKD cases were identified by an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m(2). We collected information on a wide range of potential confounders/modifiers during the medical examinations. Cux proportional hazard regression was applied to calculate hazard ratios (HRs). RESULTS: During the follow-up, 4,046 incident CKD cases were identified, and the incidence rate was 6.24 per 1,000 person-years. In contrast with participants with the first quintile exposure of PM2.5, participants with the fourth and fifth quintiles exposure of PM2.5 had increased risk of CKD development, adjusting for age, sex, educational level, smoking, drinking, body mass index, systolic blood pressure, fasting glucose, total cholesterol, and self-reported heart disease or stroke, with an HR 195% confidence interval (CI)1 of 1.11 (1.02, 1.22) and 1.15 (1.05, 1.26), respectively. A significant concentration response trend was observed (p < 0.001). Every 10 g/m3 increment in the PM2.5 concentration was associated with a 6% higher risk of developing CKD (HR: 1.06, 95% CI: 1.02, 1.10). Sensitivity and stratified analyses yielded similar results. CONCLUSIONS: Long-term exposure to ambient PM2.5 was associated with an increased risk of CKD development. Our findings reinforce the urgency to develop global strategies of air pollution reduction to prevent CKD.