title: Serum perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) concentrations and liver function biomarkers in a population with elevated PFOA exposure.
abstract: BACKGROUND
  Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) persist in the environment and are found in relatively high concentrations in animal livers. Studies in humans have reported inconsistent associations between PFOA and liver enzymes.
  
  
  OBJECTIVE
  We examined the cross-sectional association between serum PFOA and PFOS concentrations with markers of liver function in adults.
  
  
  METHODS
  The C8 Health Project collected data on 69,030 persons; of these, a total of 47,092 adults were included in the present analysis. Linear regression models were fitted for natural log (ln)-transformed values of alanine transaminase (ALT), γ-glutamyltransferase (GGT), and direct bilirubin on PFOA, PFOS, and potential confounders. Logistic regression models were fitted comparing deciles of PFOA or PFOS in relation to high biomarker levels. A multilevel analysis comparing the evidence for association of PFOA with liver function at the individual level within water districts to that at the population level between water districts was also performed.
  
  
  RESULTS
  ln-PFOA and ln-PFOS were associated with ln-ALT in linear regression models [PFOA: coefficient, 0.022; 95% confidence interval (CI): 0.018, 0.025; PFOS: coefficient, 0.020; 95% CI: 0.014, 0.026] and with raised ALT in logistic regression models [with a steady increase in the odds ratio (OR) estimates across deciles of PFOA and PFOS; PFOA: OR = 1.10; 95% CI: 1.07, 1.13; PFOS: OR = 1.13; 95% CI: 1.07, 1.18]. There was less consistent evidence of an association of PFOA and GGT or bilirubin. The relationship with bilirubin appears to rise at low levels of PFOA and to fall again at higher levels.
  
  
  CONCLUSIONS
  These results show a positive association between PFOA and PFOS concentrations and serum ALT level, a marker of hepatocellular damage.
authors.affiliation: Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Valentina
authors.initials: V
authors.lastname: Gallo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Leonardi
authors.forename: Bernd
authors.initials: B
authors.lastname: Genser
authors.forename: Maria-Jose
authors.initials: MJ
authors.lastname: Lopez-Espinosa
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Frisbee
authors.forename: Lee
authors.initials: L
authors.lastname: Karlsson
authors.forename: Alan M
authors.initials: AM
authors.lastname: Ducatman
authors.forename: Tony
authors.initials: T
authors.lastname: Fletcher
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D017738:Alkanesulfonic Acids / Q000097:blood* / Q000633:toxicity; D015415:Biomarkers / Q000097:blood*; D002210:Caprylates / Q000097:blood* / Q000633:toxicity; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000097:blood* / Q000633:toxicity; D005260:Female; D005466:Fluorocarbons / Q000097:blood* / Q000633:toxicity; D006801:Humans; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D005723:gamma-Glutamyltransferase / Q000097:blood
chemical_list: D017738:Alkanesulfonic Acids; D015415:Biomarkers; D002210:Caprylates; D004785:Environmental Pollutants; D005466:Fluorocarbons; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid; D005723:gamma-Glutamyltransferase; D000410:Alanine Transaminase