Cross-sectional associations between urinary triclosan and serum thyroid function biomarker concentrations in women: Fid-Bau Portal

Cross-sectional associations between urinary triclosan and serum thyroid function biomarker concentrations in women

Skarha, Julianne / Mínguez-Alarcón, Lidia / Williams, Paige L. / Korevaar, Tim I.M. / de Poortere, Ralph A. / Broeren, Maarten A.C. / Ford, Jennifer B. / Eliot, Melissa / Hauser, Russ / Braun, Joseph M.

Abstract

Abstract Introduction Exposure to the antimicrobial agent triclosan is ubiquitous. Research in animals shows that triclosan can cause decreases in thyroxine concentrations. However, the potential effects of triclosan on thyroid function in humans are unclear. Objective To estimate the association between urinary triclosan concentrations and serum thyroid function biomarkers in women seeking assisted reproduction treatment in the Environment and Reproductive Health (EARTH) Study. Methods We conducted a cross-sectional study of 317 women enrolled in the EARTH Study, a prospective preconception cohort that recruits Boston area couples. Using samples collected at study entry, we quantified urinary triclosan and serum thyroid function biomarker concentrations, specifically free and total thyroxine and triiodothyronine, thyroid-stimulating hormone (TSH), and thyroid antibodies. We estimated covariate-adjusted differences in thyroid function biomarkers per 10-fold increase in triclosan using linear regression models. We examined effect modification by body mass index (BMI) and infertility diagnosis. Results The median urinary triclosan concentration was 7.8 μg/L (IQR: 3.0–59 μg/L). Each 10-fold increase in triclosan was inversely associated with free triidothyronine (T3) (β: −0.06 pg/mL; 95% CI: −0.1, −0.01), thyroperoxidase antibody (TPOAb) (−10%; 95% CI: −19, −0.4), and thyroglobulin antibody (TgAb) (−12%; 95% CI: −23,0.9) concentrations. BMI and infertility diagnosis modified the association of triclosan with free T3 and TPOAb, respectively. Conclusion Urinary triclosan concentrations were inversely associated with specific serum thyroid function biomarkers in this cohort, suggesting that triclosan may affect thyroid homeostasis and autoimmunity.

Highlights • We detected triclosan in 79% of subjects; the median urinary concentration was 7.8 μg/L. • Triclosan was inversely associated with serum free triiodothyronine. • Body mass index modified the relation between triclosan and free triiodothyronine. • Triclosan was not associated with total triiodothyronine, free/total thyroxine, or TSH.