Association of ambient particle pollution with gestational diabetes mellitus and fasting blood glucose levels in pregnant women from two Chinese birth cohorts

Background: Fasting blood glucose may capture the adverse effects of air pollution on pregnant women better than the incidence of gestational diabetesmellitus (GDM), but evidence on the association between air pollution and maternal glucose concentrations is limited. Objective: To investigate the associations between air pollutants, GDM and fasting blood glucose during pregnancy. Methods: We recruited 2326 pregnant women from two birth cohorts located in Guangzhou and Heshan, the Pearl River Delta region (PRD), China. PM10, PM2.5 and black carbon (BC) exposure concentrations in the first and second trimesters of pregnancy were collected at fixed-site monitoring stations for each cohort. Multiple logistic regressions were employed to estimate the associations between particle pollution and GDM. Mixedeffects models were used to evaluate the associations of air pollutants with blood glucose levels. Restricted cubic spline functions were fitted to visualize the concentration-response relationships. Distributed lag nonlinear models were used to estimate week-specific lag effects of particle pollution exposure on GDM and blood glucose. Unconstrained distributed lag models with lags of 0-3 weeks were used to examine potential cumulative effects. Results: We observed positive and significant associations of PM10, PM2.5 and BC exposure with fasting glucose, particularly in the second trimester. PM10, PM2.5 and BC were strongly correlated and displayed similar cumulative (lag 0-3 weeks) associations with fasting blood glucose. Exposure to particle pollution was not associated with 1-h or 2-h blood glucose. Models estimating the association between air pollutants and GDM were consistent with statistical insignificance. Conclusions: Based on the results of the present study, exposure to air pollution during pregnancy exerts cumulative, adverse effects on fasting glucose levels. This study provides preliminary support for the use of blood glucose levels to explore the potential health impact of air pollution on pregnant women. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study found positive associations between exposure to PM10, PM2.5, and BC during pregnancy and fasting glucose levels, particularly in the second trimester, with cumulative effects. There was no significant association between air pollutants and gestational diabetes mellitus (GDM).