title: Cardiorespiratory Fitness and Risk of Fatty Liver: The Young Finns Study.
abstract: Fatty liver is an expanding health concern associated with metabolic disturbances and increased risk of cardiovascular disease. Experimental studies in animals have shown associations between fatty liver and cardiorespiratory fitness but limited data exist in humans. The aim of this study was to analyze the links between cardiorespiratory fitness and fatty liver in a population-based sample of adults.
  
  
  
  Participants were 463 adults (48% men) from the Cardiovascular Risk in Young Finns Study. Cardiorespiratory fitness was measured with a cycle ergometer exercise test as peak oxygen uptake (V˙O2peak [mL·kg·min]) in 2008 to 2009. Hepatic ultrasonographic imaging was performed in 2011 to determine fatty liver.
  
  
  
  Cardiorespiratory fitness was associated with lower risk of fatty liver (1 mL·kg·min increase in V˙O2peak: risk ratio, 0.90; 95% confidence interval, 0.88-0.93, P < 0.0001; adjusted for age and sex). This association remained significant after further adjustments with physical activity, adiposity, smoking, alcohol consumption, serum lipids, insulin, glucose, and C-reactive protein. Participants who were obese (waist circumference, >80 cm in women and >94 cm in men) but fit (V˙O2peak in the upper age- and sex-specific median) had lower prevalence of fatty liver than participants who were obese and unfit (below median), (11.7% vs 34.8%, P = 0.0003).
  
  
  
  In a population-based sample of adults, cardiorespiratory fitness is strongly, inversely and independently related with the risk of fatty liver. Importantly, the association is evident also among obese.
authors.affiliation: 1Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, FINLAND; 2Heart Center, Turku University Hospital, Turku, FINLAND; 3Paavo Nurmi Centre, Sports & Exercise Medicine Unit, Department of Health and Physical Activity, University of Turku and Turku University Hospital, Turku, FINLAND; 4Department of Clinical Physiology, University of Tampere, Tampere, FINLAND; 5Fimlab Laboratories, University of Tampere, Tampere, FINLAND; 6Department of Internal Medicine, University of Turku and Turku University Hospital, Turku, FINLAND; 7Division of Medicine, Turku University Hospital, Turku, FINLAND; 8Department of Clinical Chemistry, University of Tampere, Tampere, FINLAND; 9School of Medicine, University of Tampere, Tampere, FINLAND; 10Department of Medicine, University of Turku and Turku University Hospital, Turku, FINLAND; 11Department of Paediatrics, University of Tampere, Tampere, FINLAND; 12LIKES-Research Center for Sport and Health Sciences, Jyväskylä, FINLAND; and 13Department of Clinical Physiology and Nuclear Medicine, University of Turku and Turku University Hospital, Turku, FINLAND.
authors.forename: Kristiina S
authors.initials: KS
authors.lastname: Pälve
authors.forename: Katja
authors.initials: K
authors.lastname: Pahkala
authors.forename: Emmi
authors.initials: E
authors.lastname: Suomela
authors.forename: Heikki
authors.initials: H
authors.lastname: Aatola
authors.forename: Janne
authors.initials: J
authors.lastname: Hulkkonen
authors.forename: Markus
authors.initials: M
authors.lastname: Juonala
authors.forename: Terho
authors.initials: T
authors.lastname: Lehtimäki
authors.forename: Tapani
authors.initials: T
authors.lastname: Rönnemaa
authors.forename: Jorma S A
authors.initials: JSA
authors.lastname: Viikari
authors.forename: Mika
authors.initials: M
authors.lastname: Kähönen
authors.forename: Nina
authors.initials: N
authors.lastname: Hutri-Kähönen
authors.forename: Risto
authors.initials: R
authors.lastname: Telama
authors.forename: Tuija
authors.initials: T
authors.lastname: Tammelin
authors.forename: Olli T
authors.initials: OT
authors.lastname: Raitakari
mesh_terms: D000328:Adult; D015992:Body Mass Index; D000072599:Cardiorespiratory Fitness / Q000502:physiology*; D015897:Comorbidity; D005234:Fatty Liver / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D010101:Oxygen Consumption; D015995:Prevalence; D012307:Risk Factors; D014463:Ultrasonography