title: Exposure to pyrethroids insecticides and serum levels of thyroid-related measures in pregnant women.
abstract: Possible association between environmental exposure to pyrethroid insecticides and serum thyroid-related measures was explored in 231 pregnant women of 10-12 gestational weeks recruited at a university hospital in Tokyo during 2009-2011. Serum levels of free thyroxine (fT4), thyroid stimulating hormone (TSH) and thyroid biding globulin (TBG) and urinary pyrethroid insecticide metabolite (3-phenoxybenzoic acid, 3-PBA) were measured. Obstetrical information was obtained from medical records and dietary and lifestyle information was collected by self-administered questionnaire. Geometric mean concentration of creatinine-adjusted urinary 3-PBA was 0.363 (geometric standard deviation: 3.06) μg/g cre, which was consistent with the previously reported levels for non-exposed Japanese adult females. The range of serum fT4, TSH and TBG level was 0.83-3.41 ng/dL, 0.01-27.4 μIU/mL and 16.4-54.4 μg/mL, respectively. Multiple regression analysis was carried out by using either one of serum levels of thyroid-related measures as a dependent variable and urinary 3-PBA as well as other potential covariates (age, pre-pregnancy BMI, parity, urinary iodine, smoking and drinking status) as independent variables: 3-PBA was not found as a significant predictor of serum level of thyroid-related measures. Lack of association may be due to lower pyrethroid insecticide exposure level of the present subjects. Taking the ability of pyrethroid insecticides and their metabolite to bind to nuclear thyroid hormone (TH) receptor, as well as their ability of placental transfer, into consideration, it is warranted to investigate if pyrethroid pesticides do not have any effect on TH actions in fetus brain even though maternal circulating TH level is not affected.
authors.affiliation: Department of Environmental Studies, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Aya
authors.initials: A
authors.lastname: Hisada
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshinaga
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shiraishi
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Shimodaira
authors.forename: Takashi
authors.initials: T
authors.lastname: Okai
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Noda
authors.forename: Miyako
authors.initials: M
authors.lastname: Shirakawa
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Kato
mesh_terms: D000328:Adult; D001565:Benzoates / Q000652:urine; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D005260:Female; D006801:Humans; D007306:Insecticides / Q000097:blood*; D007455:Iodine / Q000652:urine; D007564:Japan; D011247:Pregnancy; D011446:Prospective Studies; D011722:Pyrethrins / Q000097:blood* / Q000633:toxicity; D012044:Regression Analysis; D012907:Smoking; D011795:Surveys and Questionnaires; D013961:Thyroid Gland / Q000187:drug effects* / Q000502:physiology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D056825:Thyroxine-Binding Globulin / Q000032:analysis
chemical_list: D001565:Benzoates; D015415:Biomarkers; D007306:Insecticides; D011722:Pyrethrins; C534944:SERPINA7 protein, human; D056825:Thyroxine-Binding Globulin; C017618:3-phenoxybenzoic acid; D013972:Thyrotropin; D007455:Iodine; D013974:Thyroxine
keywords: 3-Phenoxybenzoic acid (3-PBA); Pregnant women; Pyrethroid insecticide; Thyroid hormone