| Summary: | Ba c k g r o u n d: An increasing number of studies have shown that several ubiquitous environmental contaminants possess thyroid hormone–disrupting capacities. Prenatal exposure to some of them, such as polychlorinated biphenyls (PCBs), has also been associated with adverse neurodevelopmental effects in infants. Objectives: In this study we examined the relationship between exposure to potential thyroid hormone–disrupting toxicants and thyroid hormone status in pregnant Inuit women from Nunavik and their infants within the first year of life. Met h o d s: We measured thyroid hormone parameters [thyroid stimulating hormone (TSH), free thyroxine (fT 4), total triiodothyronine (T 3), thyroxine-binding globulin (TBG)] and concentrations of several contaminants [PCB-153, hydroxylated metabolites of PCBs (HO-PCBs), pentachlorophenol (PCP) and hexachlorobenzene (HCB)] in maternal plasma at delivery (n = 120), in umbilical cord plasma (n = 95), and in infant plasma at 7 months postpartum (n = 130). Results: In pregnant women, we found a positive association between HO-PCBs and T 3 concentrations (β = 0.57, p = 0.02). In umbilical cord blood, PCB-153 concentrations were negatively associated with TBG levels (β = –0.26, p = 0.01). In a subsample analysis, a negative relationship was also
|
|---|