Assessing the relationship between perfluoroalkyl substances, thyroid hormones and binding proteins in pregnant women; a longitudinal mixed effects approach

Berg, V; Nøst, TH; Hansen, S; Elverland, A; Veyhe, AS; Jorde, R; Odland, JØ; Sandanger, TM

HERO ID

2851002

Reference Type

Journal Article

Year

2015

Language

English

PMID

25647630

HERO ID 2851002
In Press No
Year 2015
Title Assessing the relationship between perfluoroalkyl substances, thyroid hormones and binding proteins in pregnant women; a longitudinal mixed effects approach
Authors Berg, V; Nøst, TH; Hansen, S; Elverland, A; Veyhe, AS; Jorde, R; Odland, JØ; Sandanger, TM
Journal Environment International
Volume 77
Issue Elsevier
Page Numbers 63-69
Abstract The mechanisms involved in thyroid homeostasis are complex, and perfluoroalkyl substances (PFASs) have been indicated to interfere at several levels in this endocrine system. Disruption of the maternal thyroid homeostasis during early pregnancy is of particular concern, where subclinical changes in maternal thyroid hormones (THs) may affect embryonic and foetal development. The present study investigated associations between THs, thyroid binding proteins (TH-BPs) and PFAS concentrations in pregnant women from Northern Norway. Women participating in The Northern Norway Mother-and-Child contaminant Cohort Study (MISA) donated a blood sample at three visits related to their pregnancy and postpartum period (during the second trimester, 3 days and 6 weeks after delivery) in the period 2007-2009. Participants were assigned to quartiles according to PFAS concentrations during the second trimester and mixed effects linear models were used to investigate potential associations between PFASs and repeated measurements of THs, TH-BPs, thyroxin binding capacity and thyroid peroxidase antibodies (anti-TPOs). Women within the highest perfluorooctane sulfonate (PFOS) quartile had 24% higher mean concentrations of thyroid stimulating hormone (TSH) compared to the first quartile at all sampling points. Women within the highest quartiles of perfluorodecanoate (PFDA) had 4% lower mean concentrations of triiodothyronine (T3) and women within the highest quartile of perfluoroundecanoate (PFUnDA) had 3% lower mean concentrations of free triiodothyronine (FT3). Further, the difference in concentrations and the changes between three time points were the same for the PFAS quartiles. Thyroxin binding capacity was associated with all the THs and TH-BPs, and was selected as a holistic adjustment for individual changes in TH homeostasis during pregnancy. Finally, adjusting for maternal iodine status did not influence the model predictions. Findings in the present study suggest modifications of TH homeostasis by PFASs in a background exposed maternal population. The variation in levels of THs between PFAS quartiles was within normal reference ranges and may not be of clinical significance in the pregnant woman. However, subtle individual changes in maternal THs may have significant consequences for foetal health.
Doi 10.1016/j.envint.2015.01.007
Pmid 25647630
Wosid WOS:000351786800009
Url http://www.sciencedirect.com/science/article/pii/S0160412015000185
Is Certified Translation No
Dupe Override No
Comments Journal: ISSN:
Is Public Yes
Language Text English
Keyword Thyroid hormones; Perfluoroallcyl substances; Pregnant women; Thyroxin binding capacity; Endocrine disruption