Effects of Gender on the Association of Urinary Phthalate Metabolites with Thyroid Hormones in Children: A Prospective Cohort Study in Taiwan.
Phthalates are considered endocrine disruptors. Our study assessed the gender-specific effects of phthalate exposure on thyroid function in children. In total, 189 Taiwanese children were enrolled in the study. One-spot urine and blood samples were collected for analyzing 12 phthalate metabolites in urine and thyroid hormones. The association between urinary phthalate metabolites and serum thyroid hormones was determined using a generalized linear model with a log link function; the children were categorized into groups for analysis according to the 33rd and 66th percentiles. The data were stratified according to gender and adjusted for a priori defined covariates. In girls, a positive association existed between urinary di-2-ethylhexyl phthalate (DEHP) metabolites (mono-(2-ethylhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and mono-(2-ethyl-5-hydroxyhexyl) phthalate) and free thyroxine (T4). In boys, urinary dibutyl phthalate (DBP) metabolites (mono-i-butyl phthalate and mono-n-butyl phthalate) were positively associated with free triiodothyronine (T3). After categorizing each exposure into three groups, urinary DEHP metabolites were positively associated with free T3 levels in boys. Our results suggested that DEHP is associated with free T4 in girls and that DBP is associated with free T3 in boys. Higher DEHP metabolite concentrations exerted larger effects on free T3 in boys. These results reveal the gender-specific relationships between phthalate metabolites and thyroid hormones.
Institute of Forensic Medicine, College of Medicine, National Taiwan University, Taipei 10051, Taiwan. wengtei2@ntu.edu.tw.|Forensic and Clinical Toxicology Center, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei 10051, Taiwan. wengtei2@ntu.edu.tw.|Department of Emergency Medicine, National Taiwan University Hospital, Taipei 10002, Taiwan. wengtei2@ntu.edu.tw.
Te-I
TI
Weng
Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei 10055, Taiwan. miffych@gmail.com.
Mei-Huei
MH
Chen
Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei 10055, Taiwan. f92844007@gmail.com.
Guang-Wen
GW
Lien
Institute of Forensic Medicine, College of Medicine, National Taiwan University, Taipei 10051, Taiwan. paishanchen@ntu.edu.tw.|Forensic and Clinical Toxicology Center, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei 10051, Taiwan. paishanchen@ntu.edu.tw.
Pai-Shan
PS
Chen
Department of Emergency Medicine, National Taiwan University Hospital, Taipei 10002, Taiwan. lovingbest@yahoo.com.tw.
Jasper Chia-Cheng
JC
Lin
Forensic and Clinical Toxicology Center, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei 10051, Taiwan. conrad@ntu.edu.tw.|Department of Emergency Medicine, National Taiwan University Hospital, Taipei 10002, Taiwan. conrad@ntu.edu.tw.
Cheng-Chung
CC
Fang
Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei 10055, Taiwan. pchen@ntu.edu.tw.|Department of Environmental and Occupational Medicine, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei 10051, Taiwan. pchen@ntu.edu.tw.|Department of Public Health, National Taiwan University College of Public Health,Taipei 10055, Taiwan. pchen@ntu.edu.tw.
Pau-Chung
PC
Chen
D002648:Child; D052244:Endocrine Disruptors / Q000032:analysis / Q000652:urine*; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D004785:Environmental Pollutants / Q000009:adverse effects* / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D010795:Phthalic Acids / Q000032:analysis / Q000378:metabolism* / Q000652:urine*; D011446:Prospective Studies; D012727:Sex Characteristics; D013624:Taiwan; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000187:drug effects*; D013963:Thyroid Hormones / Q000652:urine*
D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D010795:Phthalic Acids; D013963:Thyroid Hormones
children; gender; phthalates; thyroid hormones