title: Impact of physical activity on nonalcoholic steatohepatitis in people with nonalcoholic simple fatty liver: A prospective cohort study.
abstract: Preventing nonalcoholic simple fatty liver (NASFL) from progressing to nonalcoholic steatohepatitis (NASH) is a key to avoiding cirrhosis. Physical activity (PA) may help manage fatty liver; however, there is a lack of prospective studies showing an association between PA and NASH. Our current prospective study investigated whether PA prevents NASFL from progressing to NASH. Study data were obtained from the health check-up program of Meiji Yasuda Shinjuku Medical Center in Tokyo, Japan. From a baseline survey between 2005 and 2007, 1149 people with NASFL met eligibility criteria including low alcohol consumption. We followed participants until 2014 assessing liver status via ultrasound and liver enzyme levels, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST). We classified participants with fatty liver and higher levels of either ALT or AST as having NASH. Through a self-reported questionnaire, we classified PA into three intensities: moderate low-intensity PA (MLPA, 3-5 METs), moderate high-intensity PA (MHPA, 5-7 METs), and vigorous-intensity PA (VPA, ≥7 METs). During a mean follow-up of 4.2years (4804person-years), 318 of the 1149 participants (27.7%) progressed from NASFL to NASH. A multivariate-adjusted Cox model showed a significant preventive effect of VPA on progression to NASH (HR=0.55, 95% CI=0.32-0.94) and no significant associations between MLPA (HR=1.01, 95% CI=0.79-1.30) or MHPA (HR=0.97, 95% CI=0.66-1.42) and progression to NASH. Only VPA prevented NASFL from progressing to NASH; MLPA and MHPA had no preventive effect on NASH. Higher intensity PA may be needed to manage NASH.
authors.affiliation: Faculty of Social Welfare, Yamaguchi Prefectural University, 3-2-1 Sakurabatake, Yamaguchi, Yamaguchi 753-8502, Japan; Physical Fitness Research Institute, Meiji Yasuda Life Foundation of Health and Welfare, 150 Tobuki, Hachioji, Tokyo 192-0001, Japan. Electronic address: ktsunoda@yamaguchi-pu.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsunoda
authors.affiliation: Physical Fitness Research Institute, Meiji Yasuda Life Foundation of Health and Welfare, 150 Tobuki, Hachioji, Tokyo 192-0001, Japan. Electronic address: y-kai@my-zaidan.or.jp.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kai
authors.affiliation: Physical Fitness Research Institute, Meiji Yasuda Life Foundation of Health and Welfare, 150 Tobuki, Hachioji, Tokyo 192-0001, Japan. Electronic address: na-kitano@my-zaidan.or.jp.
authors.forename: Naruki
authors.initials: N
authors.lastname: Kitano
authors.affiliation: Meiji Yasuda Shinjuku Medical Center, Meiji Yasuda Life Foundation of Health and Welfare, 1-8-3 Nishi Shinjuku, Shinjuku, Tokyo 160-0023, Japan. Electronic address: ke-uchida@my-zaidan.or.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Uchida
authors.affiliation: Meiji Yasuda Wellness Development Office, Meiji Yasuda Life Foundation of Health and Welfare, 1-8-3 Nishi Shinjuku, Shinjuku, Tokyo 160-0023, Japan. Electronic address: kuchiki@my-zaidan.or.jp.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kuchiki
authors.affiliation: Physical Fitness Research Institute, Meiji Yasuda Life Foundation of Health and Welfare, 150 Tobuki, Hachioji, Tokyo 192-0001, Japan. Electronic address: nagamatsu@my-zaidan.or.jp.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Nagamatsu
mesh_terms: D000410:Alanine Transaminase / Q000032:analysis; D001219:Aspartate Aminotransferases / Q000032:analysis; D015444:Exercise / Q000502:physiology*; D005234:Fatty Liver; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000175:diagnosis*; D011446:Prospective Studies; D057566:Self Report; D011795:Surveys and Questionnaires
chemical_list: D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase
keywords: Exercise; Hepatic steatosis; NAFLD; NASH; Obesity