Changes in PM2.5-related diabetes risk under the implementation of the clean air act in Shanghai.

ABSTRACT

OBJECTIVES: We examined the associations between PM2.5 exposure and Type 2 diabetes mellitus risk under the implementation of the Clean Air Act (CAA) among high-risk population for diabetes in Shanghai. METHODS: A total of 10,499 subjects from the Shanghai High-Risk Diabetic Screen (SHiDS) project between 2002 and 2018, linked with remotely sensed PM2.5 concentrations, were enrolled in this study. Ordinary least squares and logistic regression were applied to explore associations between PM2.5 and diabetes risk in various exposure periods. RESULTS: In year 2002-2013 (before CAA), the diabetes risk increased 7.5 % (95 % CI 1.018-1.137), 8.0 % (95 % CI 1.022-1.142) and 7.9 % (95 % CI 1.021-1.141) under each 10 µg/m3 increase of long-term (1, 2 and 3 years) PM2.5 exposure, respectively. Elevated PM2.5 exposure were also associated with a significant increase in glycemic parameters before CAA implementation. However, in the year 2014-2018 (after CAA), the associations between PM2.5 exposure and diabetes risk were not significant after controlling for potential confounders. CONCLUSION: Our findings suggest that long-term and high-level exposure to PM2.5 was associated with increased prevalence of diabetes. Moreover, the implementation of CAA might ameliorate PM2.5-related diabetes risk.