title: Persistent organic pollutants and non-alcoholic fatty liver disease in morbidly obese patients: a cohort study.
abstract: BACKGROUND
  In animal experiments persistent organic pollutants (POPs) cause hepatosteatosis. In epidemiological studies POPs have positive associations with serum markers of nonalcoholic fatty liver disease (NAFLD) and together with obesity synergistic association with insulin resistance. Because insulin resistance and obesity are critical in NAFLD pathogenesis, we investigated the association of serum pollutant levels with liver histology and alanine aminotransferase (ALT) in morbidly obese.
  
  
  METHODS
  Liver biopsies were from 161 participants of the Kuopio Obesity Surgery Study (KOBS) who underwent bariatric surgery 2005-2011. Liver histology was categorized as normal, steatosis and non-alcoholic steatohepatitis (NASH). Liver phenotype at baseline and ALT at baseline and 12 months post-surgery were correlated to serum POP concentrations at respective time points. As lipophilic POPs concentrate to smaller fat volume during weight loss, serum levels before and 12 months after bariatric surgery were compared.
  
  
  RESULTS
  Baseline serum concentration of PCB-118, β-HCH and several PFAAs had an inverse association with lobular inflammation possibly due to changes in bile acid metabolism. ALT had negative associations with many POPs at baseline that turned positive at 12 months after major clinical improvements. There was an interaction between some POPs and sex at 12 months, and in stratified data positive associations were observed mainly in females but not in males.
  
  
  CONCLUSIONS
  We found a negative association between serum concentrations of PCB-118, β-HCH and several PFAAs with lobular inflammation at baseline. Positive POPs-ATL associations at 12 months among women suggest that increased POP concentrations may decrease the degree of liver recovery.
authors.affiliation: National Institute for Health and Welfare, Department of Health Protection, Chemicals and Health Unit, Kuopio, Finland. panu.rantakokko@thl.fi.
authors.forename: Panu
authors.initials: P
authors.lastname: Rantakokko
authors.affiliation: Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland. ville.mannisto@kuh.fi.
authors.forename: Ville
authors.initials: V
authors.lastname: Männistö
authors.affiliation: National Institute for Health and Welfare, Department of Health Protection, Chemicals and Health Unit, Kuopio, Finland. riikka.airaksinen@thl.fi.
authors.forename: Riikka
authors.initials: R
authors.lastname: Airaksinen
authors.affiliation: National Institute for Health and Welfare, Department of Health Protection, Chemicals and Health Unit, Kuopio, Finland. jani.koponen@thl.fi.
authors.forename: Jani
authors.initials: J
authors.lastname: Koponen
authors.affiliation: National Institute for Health and Welfare, Department of Health Protection, Chemicals and Health Unit, Kuopio, Finland. matti.viluksela@thl.fi.|Department of Environmental Science, University of Eastern Finland, Kuopio, Finland. matti.viluksela@thl.fi.
authors.forename: Matti
authors.initials: M
authors.lastname: Viluksela
authors.affiliation: National Institute for Health and Welfare, Department of Health Protection, Chemicals and Health Unit, Kuopio, Finland. hannu.kiviranta@thl.fi.
authors.forename: Hannu
authors.initials: H
authors.lastname: Kiviranta
authors.affiliation: Institute of Public Health and Clinical Nutrition, Department of Clinical Nutrition, University of Eastern Finland, Kuopio, Finland. jussi.pihlajamaki@uef.fi.|Clinical Nutrition and Obesity Center, Kuopio University Hospital, Kuopio, Finland. jussi.pihlajamaki@uef.fi.
authors.forename: Jussi
authors.initials: J
authors.lastname: Pihlajamäki
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood*; D050110:Bariatric Surgery / Q000706:statistics & numerical data; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000139:chemically induced / Q000453:epidemiology* / Q000473:pathology; D009767:Obesity, Morbid / Q000150:complications / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D000410:Alanine Transaminase