title: Prevalence of and risk factors for non-alcoholic fatty liver disease in a non-obese Japanese population, 2011-2012.
abstract: BACKGROUND
  Non-alcoholic fatty liver disease (NAFLD) in non-obese subjects is not rare in Japan, but it has not been clearly described. To clarify its prevalence and risk factors, we investigated the clinical characteristics of NAFLD in non-obese subjects in comparison with NAFLD in obese subjects in the Japanese general population.
  
  
  METHODS
  A cross-sectional study was performed with 5433 subjects who received health checkups from 2011 to 2012. Subjects consuming more than 20 g of alcohol per day and those with autoimmune liver disease, viral hepatitis, uncontrolled biliary disease and insufficient data were excluded. Subjects with a body mass index (BMI) ≥25 kg/m(2) were considered obese, and subjects with a BMI <25 kg/m(2) were considered non-obese.
  
  
  RESULTS
  A total of 3271 subjects were enrolled. The overall prevalence of NAFLD was 24.6%: 68.5% in obese subjects and 15.2% in non-obese subjects. The multivariate logistic regression analysis revealed that ≥10 kg of weight gain since the age of 20 was significantly associated with NAFLD in non-obese subjects of both genders, and eating an evening meal within 2 h before going to bed 3 days or more per week and drinking <20 g of alcohol per day were negatively associated in non-obese females. Metabolic factors such as waist circumference and triglycerides were predictors of NAFLD in non-obese subjects, and body fat percentage was a predictor in non-obese males.
  
  
  CONCLUSIONS
  Lifestyle as well as metabolic factors may play crucial roles in the pathogenesis of NAFLD, even in the non-obese Japanese population.
authors.affiliation: Health Care Division, Kyoto Second Red Cross Hospital, 355-5 Haruobi-cho, Kamigyo-ku, Kyoto, 602-8026, Japan, k.nishioji@kyoto2.jrc.or.jp.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nishioji
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Sumida
authors.forename: Mai
authors.initials: M
authors.lastname: Kamaguchi
authors.forename: Naomi
authors.initials: N
authors.lastname: Mochizuki
authors.forename: Masao
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishimura
authors.forename: Kanji
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Itoh
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000453:epidemiology* / Q000209:etiology; D009765:Obesity / Q000453:epidemiology; D010808:Physical Examination / Q000379:methods; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult