title: High cardiorespiratory fitness is an independent predictor of the reduction in liver fat during a lifestyle intervention in non-alcoholic fatty liver disease.
abstract: OBJECTIVE
  Lifestyle intervention with diet modification and increase in physical activity is effective for reducing hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD). However, for a similar weight loss, there is a large variability in the change in liver fat. We hypothesised that cardiorespiratory fitness may predict the response to the intervention.
  
  
  METHODS
  Longitudinal study with increase in physical activity and diet modification.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  50 adults with NAFLD and 120 controls at risk for metabolic diseases.
  
  
  METHODS
  Total-, subcutaneous abdominal- and visceral adipose tissue by magnetic resonance tomography, liver fat by 1HMR spectroscopy and cardiorespiratory fitness (VO(2,max)) by a maximal cycle exercise test at baseline and after 9 months of follow-up.
  
  
  RESULTS
  In all subjects total-, subcutaneous abdominal- and visceral adipose tissue decreased and fitness increased (all p<0.0001) during the intervention. The most pronounced changes were found for liver fat (-31%, p<0.0001). Among the parameters predicting the change in liver fat, fitness at baseline emerged as the strongest factor, independently of total- and visceral adipose tissue as well as exercise intensity (p = 0.005). In the group of subjects with NAFLD at baseline, a resolution of NAFLD was found in 20 individuals. For 1 standard deviation increase in VO(2,max) at baseline the odds ratio for resolution of NAFLD was 2.79 (95% confidence interval, 1.43-6.33).
  
  
  CONCLUSIONS
  Cardiorespiratory fitness, independently of total adiposity, body fat distribution and exercise intensity, determines liver fat content in humans, suggesting that fitness and liver fat are causally related to each other. Moreover, measurement of fitness at baseline predicts the effectiveness of a lifestyle intervention in reducing hepatic steatosis in patients with NAFLD.
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, University of Tübingen, Tübingen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Kantartzis
authors.forename: C
authors.initials: C
authors.lastname: Thamer
authors.forename: A
authors.initials: A
authors.lastname: Peter
authors.forename: J
authors.initials: J
authors.lastname: Machann
authors.forename: F
authors.initials: F
authors.lastname: Schick
authors.forename: C
authors.initials: C
authors.lastname: Schraml
authors.forename: A
authors.initials: A
authors.lastname: Königsrainer
authors.forename: I
authors.initials: I
authors.lastname: Königsrainer
authors.forename: S
authors.initials: S
authors.lastname: Kröber
authors.forename: A
authors.initials: A
authors.lastname: Niess
authors.forename: A
authors.initials: A
authors.lastname: Fritsche
authors.forename: H-U
authors.initials: HU
authors.lastname: Häring
authors.forename: N
authors.initials: N
authors.lastname: Stefan
mesh_terms: D000328:Adult; D001823:Body Composition; D016022:Case-Control Studies; D003131:Combined Modality Therapy; D004038:Diet, Reducing; D005080:Exercise Test; D005081:Exercise Therapy; D005234:Fatty Liver / Q000178:diet therapy / Q000473:pathology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006801:Humans; D050152:Intra-Abdominal Fat / Q000473:pathology; D008019:Life Style; D016014:Linear Models; D016015:Logistic Models; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D050507:Subcutaneous Fat, Abdominal / Q000473:pathology; D016896:Treatment Outcome; D051598:Whole Body Imaging