Perfluoroalkyl substances, glucose homeostasis, and gestational diabetes mellitus in Chinese pregnant women: A repeat measurement-based prospective study

Background: Exposure to perfluoroalkyl substances (PFASs) can affect glucose homeostasis and has been suggested as a potential risk of diabetes mellitus, but data are limited for pregnant women. Objectives: We aimed to explore the associations of exposure to PFASs with glucose homeostasis and gestational diabetes mellitus (GDM) in Chinese pregnant women. Methods: The current study was conducted in Hebei Province of Northern China between 2013 and 2014 and 560 pregnant women were recruited in their early term of pregnancy and two representative serum PFASs, perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), were measured. In 385 pregnant women who completed oral glucose tolerance test (OGTT), the associations of serum PFOA and PFOS concentrations with fasting blood glucose (FBG), fasting insulin (FIns), and homeostasis model assessment of insulin resistance (HOMA-IR) in the early, middle, and late terms of pregnancy and occurrence of GDM were examined using linear and Cox proportional hazard regression models. The reproducibility of serum PFASs during pregnancy was assessed in 230 pregnant women. Results: The intraclass correlation coefficients of serum PFASs, covariates, and outcomes based on averaged repeat measurement (0.35-0.96) were higher than those based on single measurement (0.16-0.92). Serum PFOA was positively associated with averaged FIns and HOMA-IR in the early, middle, and late terms of pregnancy and averaged blood glucose level at 1 h and 2 h of OGTT, but serum PFOS tended to be negatively associated with averaged FBG and OGTT blood glucose. The adjusted hazard ratios of GDM associated with serum PFOA and PFOS were 1.98 (95% confidence interval: 0.70-5.57; p-value: 0.197) and 0.71 (0.29-1.75; 0.453), respectively. Conclusions: Our data raised a possibility that exposure to PFASs might have different influences on glucose homeostasis and GDM in Chinese pregnant women. More lab and human studies are needed to further test the hypothesis and investigate potential mechanisms.