The impact of PM 2.5 and its constituents on gestational diabetes mellitus: a retrospective cohort study.

Background: There is increasing evidence that exposure to PM _2.5 and its constituents is associated with an increased risk of gestational diabetes mellitus (GDM), but studies on the relationship between exposure to PM _2.5 constituents and the risk of GDM are still limited.
Methods: A total of 17,855 pregnant women in Guangzhou were recruited for this retrospective cohort study, and the time-varying average concentration method was used to estimate individual exposure to PM _2.5 and its constituents during pregnancy. Logistic regression was used to assess the relationship between exposure to PM _2.5 and its constituents and the risk of GDM, and the expected inflection point between exposure to PM _2.5 and its constituents and the risk of GDM was estimated using logistic regression combined with restricted cubic spline curves. Stratified analyses and interaction tests were performed.
Results: After adjustment for confounders, exposure to PM _2.5 and its constituents (NO ₃ ^- , NH ₄ ⁺ , and OM) was positively associated with the risk of GDM during pregnancy, especially when exposure to NO ₃ ^- and NH ₄ ⁺ occurred in the first to second trimester, with each interquartile range increase the risk of GDM by 20.2% (95% CI: 1.118-1.293) and 18.2% (95% CI. 1.107-1.263), respectively. The lowest inflection points between PM _2.5 , SO ₄ ^2- , NO ₃ ^- , NH ₄ ⁺ , OM, and BC concentrations and GDM risk throughout the gestation period were 18.96, 5.80, 3.22, 2.67, 4.77 and 0.97 µg/m ³ , respectively. In the first trimester, an age interaction effect between exposure to SO ₄ ^2- , OM, and BC and the risk of GDM was observed.
Conclusions: This study demonstrates a positive association between exposure to PM _2.5 and its constituents and the risk of GDM. Specifically, exposure to NO ₃ ^- , NH ₄ ⁺ , and OM was particularly associated with an increased risk of GDM. The present study contributes to a better understanding of the effects of exposure to PM _2.5 and its constituents on the risk of GDM.
(© 2024. The Author(s).)