Exposure to pyrethroids insecticides and serum levels of thyroid-related measures in pregnant women

• Published in: Environmental research Vol. 127; pp. 16 - 21
• Main Authors: Zhang, Jie, Hisada, Aya, Yoshinaga, Jun, Shiraishi, Hiroaki, Shimodaira, Kazuhisa, Okai, Takashi, Noda, Yumiko, Shirakawa, Miyako, Kato, Nobumasa
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.11.2013; Elsevier
• Subjects: 3-Phenoxybenzoic acid (3-PBA); Adult; Adults; Benzoates - urine; Biological and medical sciences; BIOLOGICAL MARKERS; Biomarkers - urine; blood serum; body mass index; BRAIN; Circulating; Cohort Studies; CONCENTRATION RATIO; CREATININE; drinking; ENVIRONMENTAL EXPOSURE; Environmental Exposure - adverse effects; Environmental Exposure - analysis; ENVIRONMENTAL SCIENCES; Exposure; Female; females; FETUSES; GLOBULINS; Hormones; HOSPITALS; Humans; INSECTICIDES; Insecticides - blood; IODINE; Iodine - urine; Japan; lifestyle; Medical; MEDICAL RECORDS; Medical sciences; Metabolites; NUTRITION; Pesticides, fertilizers and other agrochemicals toxicology; PREGNANCY; Pregnant women; Prospective Studies; pyrethrins; Pyrethrins - blood; Pyrethrins - toxicity; Pyrethroid insecticide; pyrethroid insecticides; questionnaires; RECEPTORS; REGRESSION ANALYSIS; Serums; SMOKES; Smoking; STATISTICAL MODELS; Surveys and Questionnaires; THYROID; Thyroid gland; Thyroid Gland - drug effects; Thyroid Gland - physiology; Thyroid hormone; thyroid hormones; thyrotropin; Thyrotropin - blood; THYROXINE; Thyroxine - blood; Thyroxine-Binding Globulin - analysis; Toxicology; TSH; WOMEN; Asia; Japan; Pyrethroid insecticide; Thyroid hormone; Pregnant women; 3-Phenoxybenzoic acid (3-PBA); Human; Biological fluid; Endocrine gland; Insecticide; Pesticides; Pyrethroids; Exposure; Thyroid gland; Pregnancy; Concentration measurement; Adult; Female; Serum; Woman; Public health
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2013.10.001

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 0.83–3.41ng/dL, 0.01–27.4μIU/mL and 16.4–54.4μg/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. •Pyrethroid exposure and thyroid hormone status was examined in pregnant women.•Urinary 3-phenoxybenzoic acid was used as a biomarker of exposure.•Iodine nutrition, age and other covariates were included in statistical models.•No association was found between levels of thyroid hormone and pyrethroid exposure.•The result may be ascribed to lower exposure level.