Associations of long-term exposure to particulate matter with gallstone risks in Chinese adults: A large cross-sectional study

Background: Epidemiological evidence regarding the relation of exposure to ambient particulate matter (PM) with gallstone disease (GSD) risk remains lacking. We tested the hypothesis that long-term exposure to PM is related to the development of GSD and that dyslipidemia can mediate the effect of PM-associated GSD formation. Methods: We extracted related information on the basis of the baseline survey of the China Multi-Ethnic Cohort Study. The exposure levels of PM (PM1, PM2.5, and PM10) were assessed by validated spatiotemporal models. The relation of exposure to ambient PM with GSD risks was analyzed by non-conditional logistic regression models. Additionally, mediation analysis was conducted to assess whether dyslipidemia was related to the relation of PM exposure with GSD risks. Results: A total of 72,893 participants were included. Increased ambient PM exposure was positively associated with a higher GSD risk, with ORs (and 95% CI) of 1.17 (1.06, 1.28), 1.10 (1.05, 1.15), and 1.07 (1.04, 1.10) for every 10 mu g/m3 increment in PM1, PM2.5, and PM10, separately. The association was more remarkable in males, drinkers, and central obesity participants. Dyslipidemia significantly mediated the association between PM and GSD, with mediating proportions of 5.37%, 9.13%, and 7.66% in PM1, PM2.5, and PM10, respectively. Conclusion: Exposure to PM may relate to the increased risk of GSD in Chinese adults, especially among males, drinkers, and central obesity participants. Dyslipidemia may partially mediate the effect of PM-associated GSD development. Our results might provide epidemiological evidence for the progression of GSD related to PM and give new insights into GSD prevention and screening priorities.