Growing evidence suggests that PM2.5 is associated with diabetes mellitus (DM). Although DM is a major public health concern, there has not yet been a study of this association in Japan. We used health examination data from 66,885 individuals in Tokyo, Japan 2005-2019. Cox proportional hazards models were used to evaluate an association between annual exposure to PM2.5 and glycated hemoglobin A1c (HbA1c), or fasting plasma glucose (FPG). An increase of 1 μg/m3 in the annual average of PM2.5 concentration was associated (HR = 1.029; 95% CI = 1.004-1.055) with an increase in diabetes (incident + prevalent). For incident DM, a greater PM2.5 level was associated with more DM (HR = 1.029; 95% CI, 1.003-1.055). Compared to HbA1c, FPG showed a stronger association with the annual exposure to PM2.5 (HR = 1.065; 95% CI, 1.040-1.091). We found that greater exposure to PM2.5 in the long-term was associated with an increased risk of diabetes, and that the magnitude of association became stronger as the exposure duration increased. Omorogieva Ojo.
Keywords: Japan; PM2.5; Tokyo; air pollution; diabetes mellitus; particulate matter.