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. In this study, the authors estimated 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. A cross-sectional study was conducted of 317 women enrolled in the EARTH Study, a prospective preconception cohort that recruits Boston area couples. Using samples collected at study entry, the authors quantified urinary triclosan and serum thyroid function biomarker concentrations, specifically free and total thyroxine and triiodothyronine, thyroid-stimulating hormone (TSH), and thyroid antibodies.
Covariate-adjusted differences were estimated in thyroid function biomarkers per 10-fold increase in triclosan using linear regression models. The effect modification by body mass index (BMI) and infertility diagnosis were examined. The median urinary triclosan concentration was 7.8??g/L (IQR: 3.0-59??g/L). Each 10-fold increase in triclosan was inversely associated with free triidothyronine (T3) (?: -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. Urinary triclosan concentrations were inversely associated with specific serum thyroid function biomarkers in this cohort, suggesting that triclosan may affect thyroid homeostasis and autoimmunity.
Authors: Skarha J, Mínguez-Alarcón L, Williams PL, Korevaar TIM, de Poortere RA, Broeren MAC, Ford JB, Eliot M, Hauser R, Braun JM. ; Full Source: Environment International. 2019 Jan; 122:256-262. doi: 10.1016/j.envint.2018.11.015. Epub 2018 Nov 23.