Exposure to Fine Particulate Matter Increases Risk of Diabetes Mellitus

Objective This nationwide cohort study aimed to examine the association between PM2.5 and diabetes mellitus (DM) risk. Methods We recorded annual average PM2.5 exposure levels at participants' locations. PM2.5 concentrations were categorized into quartiles: Q1 (<29.5 mu g/m(3)), Q2 (29.5-33.3 mu g/m(3)), Q3 (33.4-41.2 mu g/m(3)), and Q4 (>41.2 mu g/m(3)). Results A total of 158,038 patients (69,688 men and 88,350 women) were enrolled. Diabetes mellitus incidence increased with higher annual PM2.5 concentrations (2.81 in Q1, 3.06 in Q2, 3.65 in Q3, and 3.89 in Q4 per 10,000 person-years). After adjusting for confounders, patients exposed to PM2.5 in Q2, Q3, and Q4 had adjusted hazard ratios of 1.14 (95% CI: 1.05-1.23), 1.40 (95% CI: 1.30-1.50), and 1.42 (95% CI: 1.32-1.53), respectively, for developing DM compared with those exposed to Q1-PM2.5 concentrations. Conclusions This study observed an increased risk of DM associated with PM2.5 exposure.