Long-Term Effects of Ambient PM2∙5 Exposure on Chronic Kidney Disease in Chinese Adults:A Longitudinal Cohort Study

Background: While increasing evidence have linked fine particulate matter (PM2∙5) to chronic kidney disease (CKD), it has not yet been fully elucidated, especially in developing countries with higher level of PM2∙5. We tested the association between ambient PM2∙5 and risk of CKD in a large Chinese cohort study. Methods: We included 72,425 participants (≥ 18 years) without baseline CKD between 2005 to 2018. Annual mean PM2∙5 levels at individuals’ residential addresses were obtained from a long-term, full-coverage, and high-resolution dataset at 1×1 km resolution. We used Cox proportional hazards models to estimate the effects of long-term PM2∙5 exposure with distinct windows and the joint effects of PM2∙5 with temperature or humidity on incident CKD, controlling for major confounders. Restricted cubic splines were used to model exposure-response relationships. Results: Over a median follow-up of 3∙79 years (range = 2∙03-5∙48), participants were exposed to a median PM2∙5 concentration of 72∙27 μg/m 3 (range = 61∙21-74∙88). Compared with the lowest quartile, the fully adjusted hazard ratios (HRs) and 95% confidence interval (CI) of long-term PM2∙5 exposure were 3∙07 (2∙60-3∙62) for incident CKD ( p < 0∙001). Evidence of overall additive interaction for joint effect analysis was only found in humidity (RERI, 6∙28; 95% CI, 2∙09-10∙47).Interpretation Long-term higher ambient PM2∙5 exposure associated with an increased risk of CKD in mainland China, especially in high humidity areas. Funding: The National Natural Science Foundation of China, The Outstanding Young Investigator of Hunan province, The Hunan Youth Talent Project, and The National key research and development program. Declaration of Interest: The authors declare no conflict of interest. Ethical Approval: Ethics approval of our study was obtained from the Institutional Review Board of The Third Xiangya Hospital of Central South University (No. R18030).