Thyroid hormone levels of pregnant Inuit women and their infants exposed to environmental contaminants

Dallaire, R; Muckle, G; Dewailly, É; Jacobson, SW; Jacobson, JL; Sandanger, TM; Sandau, CD; Ayotte, P

HERO ID

199563

Reference Type

Journal Article

Year

2009

Language

English

PMID

19590699

HERO ID 199563
In Press No
Year 2009
Title Thyroid hormone levels of pregnant Inuit women and their infants exposed to environmental contaminants
Authors Dallaire, R; Muckle, G; Dewailly, É; Jacobson, SW; Jacobson, JL; Sandanger, TM; Sandau, CD; Ayotte, P
Journal Environmental Health Perspectives
Volume 117
Issue 6
Page Numbers 1014-1020
Abstract Background: 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. Methods: We measured thyroid hormone parameters [thyroid stimulating hormone (TSH), free thyroxine (fT4), total triiodothyronine (T3), 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 T3 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 found between maternal PCP levels and cord fT4 concentrations in neonates (β = –0.59, p = 0.02). No association was observed between contaminants and thyroid hormones at 7 months of age. Conclusion: Overall, there is little evidence that the environmental contaminants analyzed in this study affect thyroid hormone status in Inuit mothers and their infants. The possibility that PCP may decrease thyroxine levels in neonates requires further investigation.
Doi 10.1289/ehp.0800219
Pmid 19590699
Wosid WOS:000266462600043
Url http://dx.doi.org/10.1289/ehp.0800219
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword cohort; cord blood; Inuit; metabolites; organochlorines; pentachlorophenol; polychlorinated biphenyls; pregnant women; prenatal exposure; thyroid hormones
Is Qa No