title: Physical Activity Is Prospectively Associated With Adolescent Nonalcoholic Fatty Liver Disease.
abstract: OBJECTIVE
  The aim of the present study was to assess whether objectively measured physical activity at mean ages 12 and 14 years are prospectively associated with ultrasound scan liver fat and stiffness (alanine aminotransferase, aspartate aminotransferase [AST], and γ-glutamyl transferase [GGT]) assessed at mean age 17.8 years.
  
  
  METHODS
  Participants were from the Avon Longitudinal Study of Parents and Children. Total physical activity (counts per minute) and minutes of moderate to vigorous physical activity (MVPA) were measured using ActiGraph accelerometers at mean ages 12 and 14 years.
  
  
  RESULTS
  Greater total physical activity and MVPA at ages 12 and 14 years were associated with lower odds of liver fat and lower GGT levels at mean age 17.8 years, such as per 15-minute increase in daily MVPA at age 12 years, the confounder adjusted odds ratio of liver fat was 0.47 (95% confidence interval [CI] 0.27-0.84). Associations attenuated after additional adjustment for fat mass as a potential confounder (eg, per 15-minute increase in daily MVPA at age 12 years, the odds ratio of liver fat attenuated to 0.65 [95% CI 0.35-1.21]) or a potential mediator (eg, per 15-minute increase in daily MVPA at age 12 years the odds ratio of liver fat attenuated to 0.59 [95% CI 0.32-1.09]). Results did not further attenuate after additional adjustment for insulin resistance. There was some evidence that greater total physical activity and MVPA at age 12 years were associated with the higher AST levels.
  
  
  CONCLUSIONS
  Adolescents who were more active in childhood have lower odds of fatty liver and lower GGT levels. These findings are likely to be, at least in part, explained by adiposity.
authors.affiliation: *MRC Integrative Epidemiology †School of Social and Community Medicine, University of Bristol ‡University Hospitals Bristol NHS Foundation Trust, Bristol §Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, Faculty of Medicine, University of Glasgow, Glasgow ||Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Anderson
authors.forename: Abigail
authors.initials: A
authors.lastname: Fraser
authors.forename: Laura D
authors.initials: LD
authors.lastname: Howe
authors.forename: Mark P
authors.initials: MP
authors.lastname: Callaway
authors.forename: Naveed
authors.initials: N
authors.lastname: Sattar
authors.forename: Chris
authors.initials: C
authors.lastname: Day
authors.forename: Kate
authors.initials: K
authors.lastname: Tilling
authors.forename: Debbie A
authors.initials: DA
authors.lastname: Lawlor
mesh_terms: D050154:Adiposity; D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D002648:Child; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000201:enzymology / Q000503:physiopathology*; D008111:Liver Function Tests; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D014463:Ultrasonography; D005723:gamma-Glutamyltransferase / Q000097:blood
chemical_list: D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase