The Associations Of Ambient Fine Particulate Matter Exposure During Pregnancy With Blood Glucose Levels And Gestational Diabetes Mellitus Risk: A Prospective Cohort Study In Wuhan, China

Investigators in previous studies have drawn inconsistent conclusions regarding the relationship between relatively low exposure to fine particulate matter (particulate matter with an aerodynamic diameter <= 2.5 mu m (PM2.5)) and risk of gestational diabetes mellitus (GDM), while the association between high PM2.5 exposure and GDM risk has not been well studied. We investigated the association of high PM2.5 exposure during pregnancy with blood glucose levels and GDM risk in Chinese women. The present study was conducted from August 2013 to May 2016 among 3,967 pregnant women in the Tongji Maternal and Child Health Cohort in Wuhan, China. PM2.5 exposure during pregnancy for each participant was estimated by means of land-use regression models. An interquartile-range increase in PM2.5 exposure (33.84 mu g/m(3) for trimester 1 and 33.23 mu g/m(3) for trimester 2) was associated with 36% (95% confidence interval (CI): 1.15, 1.61) and 23% (95% CI: 1.01, 1.50) increased odds of GDM during trimester 1 and trimester 2, respectively. An interquartile-range increment of PM2.5 exposure during trimester 1 increased 1-hour and 2-hour blood glucose levels by 1.40% (95% CI: 0.42, 2.37) and 1.82% (95% CI: 0.98, 2.66), respectively. The same increment of PM2.5 exposure during trimester 2 increased fasting glucose level by 0.85% (95% CI: 0.41, 1.29). Our findings suggest that high PM2.5 exposure during pregnancy increases blood glucose levels and GDM risk in Chinese women.