Health-related fitness and physical activity in patients with nonalcoholic fatty liver disease


  • Joanne B. Krasnoff,

    Corresponding author
    1. Exercise Physiology and Body Composition Laboratory, CTSI Clinical Research Center, University of California San Francisco, San Francisco, CA
    • University of California San Francisco, CTSI Clinical Research Center, Exercise Physiology & Body Composition Laboratory, 505 Parnassus Avenue, Box 0126, San Francisco, CA 94143-0126
    Search for more papers by this author
    • fax: 415-476-0986.

  • Patricia L. Painter,

    1. Division of Renal Diseases and Hypertension, University of Minnesota, Minneapolis, MN
    Search for more papers by this author
  • Janet P. Wallace,

    1. Clinical Exercise Physiology Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN
    Search for more papers by this author
  • Nathan M. Bass,

    1. Division of Gastroenterology, University of California San Francisco, San Francisco, CA
    Search for more papers by this author
  • Raphael B. Merriman

    1. Division of Gastroenterology, California Pacific Medical Center and Research Institute, San Francisco, CA
    Search for more papers by this author

  • Its contents are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH.

  • Potential conflict of interest: Nothing to report.


Nonalcoholic fatty liver disease (NAFLD) has been referred to as the hepatic manifestation of the metabolic syndrome. There is a lower prevalence of metabolic syndrome in individuals with higher health-related fitness (HRF) and physical activity (PA) participation. The relationship between NAFLD severity and HRF or PA is unknown. Our aim was to compare measures of HRF and PA in patients with a histological spectrum of NAFLD severity. Thirty-seven patients with liver biopsy–confirmed NAFLD (18 women/19 men; age = 45.9 ± 12.7 years) completed assessment of cardiorespiratory fitness (CRF, VO2peak), muscle strength (quadriceps peak torque), body composition (%fat), and PA (current and historical questionnaire). Liver histology was used to classify severity by steatosis (mild, moderate, severe), fibrosis stage (stage 1 versus stage 2/3), necroinflammatory activity (NAFLD Activity Score; ≤4 NAS1 versus ≥5 NAS2) and diagnosis of NASH by Brunt criteria (NASH versus NotNASH). Analysis of variance and independent t tests were used to determine the differences among groups. Fewer than 20% of patients met recommended guidelines for PA, and 97.3% were classified at increased risk of morbidity and mortality by %fat. No differences were detected in VO2peak (x = 26.8 ± 7.4 mL/g/min) or %fat (x = 38.6 ± 8.2%) among the steatosis or fibrosis groups. Peak VO2 was significantly higher in NAS1 versus NAS2 (30.4 ± 8.2 versus 24.4 ± 5.7 mL/kg/min, P = 0.013) and NotNASH versus NASH (34.0 ± 9.5 versus 25.1 ± 5.7 mL/kg/min, P = 0.048). Conclusion: Patients with NAFLD of differing histological severity have suboptimal HRF. Lifestyle interventions to improve HRF and PA may be beneficial in reducing the associated risk factors and preventing progression of NAFLD. (HEPATOLOGY 2008.)