Maternal exposure to trace elements and perfluoroalkyl acids and their associations with alterations of the hypothalamic-pituitary-adrenal axis.

Environmental exposures to trace elements and perfluoroalkyl acids (PFAAs) could alter hypothalamic-pituitary-adrenal (HPA) function during pregnancy. Concentrations of trace elements measured in maternal red blood cells and PFAAs measured in maternal plasma, as well as maternal salivary cortisol were quantified from second trimester samples in 243 women from the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort. Regression analyses examine associations between trace elements and PFAAs, and cortisol awakening response (CAR), daytime cortisol and diurnal cortisol slope. Bayesian kernel machine regression (BKMR) analyses investigated mixture effects. In single exposure models, molybdenum (β = -0.99, 95 % CI = -1.74, -0.24) was negatively associated with CAR and lead was negatively associated with daytime cortisol (β = -13.3, 95 % CI = -25.65, -1.10); perfluoroheptanoic acid (PFHpA) was positively associated (β = 4.29, 95 % CI = 0.68, 7.90) with daytime cortisol. In sex-specific analyses molybdenum was negatively associated with CAR and lead was negatively associated with daytime cortisol in women who gave birth to female infants. PFHpA and perfluorohexanesulfonic acid (PFHxS), were positively associated with daytime cortisol in women who gave birth to male infants. Arsenic, mercury, zinc, PFHxS and perfluorooctanesulfonic acid (PFOS) were positively associated with diurnal cortisol slope in the women who gave birth to female infants. No associations survived correction for false discovery rate. In mixture models, molybdenum was the main contributor to CAR in women who gave birth to female infants; PFHpA contributed the most to daytime cortisol in women who gave birth to male infants. Exposure to trace elements and PFAAs in pregnancy may be associated with alterations in maternal HPA axis function.