title: Perfluoroalkyl substances and thyroid hormones in cord blood.
abstract: BACKGROUND
  Perfluoroalkyl substances (PFASs) are pollutants that tend to accumulate in the environment and organisms. The animal and human studies to date have focused on thyroid function, but the results are inconsistent.
  
  
  METHODS
  A sample of 118 mother-infant pairs was obtained from the Taiwan Birth Panel Study (TBPS). Cord blood PFASs levels were evaluated using the Waters ACQUITY UPLC system coupled with a Waters Quattro Premier XE triple quadrupole mass spectrometer, and cord blood thyroid hormones were assessed using a Roche Analytics E170 modular analyser (Roche Diagnostics, Mannheim, Germany). PFASs concentrations were analysed in the final models to examine the associations between cord blood PFASs levels and thyroid hormone concentrations.
  
  
  RESULTS
  The cord blood perfluorooctane sulfonate (PFOS) concentration was negatively associated with the cord blood thyroxine (T4) concentration [per ln unit: adjusted β (95% confidence interval, CI) = -0.458(-0.916, -0.001)]. Moreover, the level of cord blood thyroid stimulating hormone (TSH) was positively associated with the cord blood PFOS concentration [per ln unit: adjusted β (95% confidence interval, CI) = 0.346(0.101, 0.592)]. The sex stratified effects of PFOS on T4 were suggestive of differential effects in high-exposure groups compared with low-exposure group in boys.
  
  
  CONCLUSIONS
  We found that cord blood thyroid hormone levels are affected by PFASs, with a negative association between T4 and PFOS and a positive association between TSH and PFOS. The causal associations of thyroid hormones and PFASs require further exploration.
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Meng-Shan
authors.initials: MS
authors.lastname: Tsai
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Ching-Chun
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Taiwan.
authors.forename: Mei-Huei
authors.initials: MH
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.
authors.forename: Wu-Shiun
authors.initials: WS
authors.lastname: Hsieh
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Public Health, National Taiwan University College of Public Health, Taipei, Taiwan; Department of Environmental and Occupational Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: pchen@ntu.edu.tw.
authors.forename: Pau-Chung
authors.initials: PC
authors.lastname: Chen
mesh_terms: D017738:Alkanesulfonic Acids / Q000097:blood; D000818:Animals; D002210:Caprylates / Q000097:blood; D004785:Environmental Pollutants / Q000097:blood*; D005227:Fatty Acids / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005466:Fluorocarbons / Q000097:blood*; D006801:Humans; D008297:Male; D013624:Taiwan; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D004785:Environmental Pollutants; D005227:Fatty Acids; D005466:Fluorocarbons; C586085:perfluoroundecanoic acid; C101816:perfluoro-n-nonanoic acid; D013972:Thyrotropin; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid; D013974:Thyroxine
keywords: Cord blood; Perfluoroalkyl substances; Thyroid hormone