Long-term exposure to fine particulate matter constituents in relation to chronic kidney disease: evidence from a large population-based study in China.

The effects of long-term exposure to fine particulate matter (PM_2.5) constituents on chronic kidney disease (CKD) are not fully known. This study sought to examine the association between long-term exposure to major PM_2.5 constituents and CKD and look for potential constituents contributing substantially to CKD. This study included 81,137 adults from the 2018 to 2019 baseline survey of China Multi-Ethnic Cohort. CKD was defined by the estimated glomerular filtration rate. Exposure concentration data of 7 major PM_2.5 constituents were assessed by satellite remote sensing. Logistic regression models were used to estimate the effect of each PM_2.5 constituent exposure on CKD. The weighted quantile sum regression was used to estimate the effect of mixed exposure to all constituents. PM_2.5 constituents had positive correlations with CKD (per standard deviation increase), with ORs (95% CIs) of 1.20 (1.02–1.41) for black carbon, 1.27 (1.07–1.51) for ammonium, 1.29 (1.08–1.55) for nitrate, 1.20 (1.01–1.43) for organic matter, 1.25 (1.06–1.46) for sulfate, 1.30 (1.11–1.54) for soil particles, and 1.63 (1.39–1.91) for sea salt. Mixed exposure to all constituents was positively associated with CKD (1.68, 1.32–2.11). Sea salt was the constituent with the largest weight (0.36), which suggested its importance in the PM_2.5-CKD association, followed by nitrate (0.32), organic matter (0.18), soil particles (0.10), ammonium (0.03), BC (0.01). Sulfate had the least weight (< 0.01). Long-term exposure to PM_2.5 sea salt and nitrate may contribute more than other constituents in increasing CKD risk, providing new evidence and insights for PM_2.5-CKD mechanism research and air pollution control strategy. [ABSTRACT FROM AUTHOR]