Long-term exposure to fine particulate matter and fasting blood glucose and diabetes mellitus in 20 million Chinese women of reproductive age

Objective: Evidence on the associations between fine particulate matter (PM2.5) and diabetes risk from women of reproductive age, on whom diabetes may have adverse long-term health effects on both themselves and future generations, remains scarce. We therefore examined the associations of long-term PM2.5 exposure with fasting blood glucose (FBG) levels and diabetes risk among reproductive-aged women in China.

Research Design and Methods: This study included 20,076,032 women aged 20-49 years participating in the National Free Preconception Health Examination Project in China between 2010 and 2015. PM2.5 was estimated utilizing a satellite-based model. Multivariate linear and logistic regression models were used to examine the associations of PM2.5 exposure with FBG level and diabetes risk, respectively. Diabetes burden attributable to PM2.5 was estimated using attributable fraction (AF) and attributable number.

Results: PM2.5 showed monotonic relationships with elevated FBG level and diabetes risk. Each interquartile range (IQR, 27 μg/m3) increase in 3-year average PM2.5 concentration was associated with 0.078 mmol/L (95% confidence interval [CI]: 0.077, 0.079) increase of FBG and 18% (95%CI: 16%, 19%) higher risk of diabetes. The AF attributed to PM2.5 exposure exceeding 5 μg/m3 was 29.0% (95%CI: 27.5%, 30.5%), corresponding to an additional 78.6 (95%CI: 74.5, 82.6) thousand diabetes cases. Subgroup analyses showed more pronounced diabetes risks among those who were overweight or obese, above 35 years, less educated, of minority ethnicity, with rural household registration, and residing in Western China.

Conclusions: We found long-term PM2.5 exposure was associated with higher diabetes risk among women of reproductive age in China.