title: Epidemiology of fatty liver in an islander population of China: a population-based case-control study.
abstract: BACKGROUND
  Because of difficulty in evaluating fatty liver disease in islander populations, we conducted a cross-sectional study to investigate the prevalence of fatty liver and its risk factors in an islander population of East China.
  
  
  METHODS
  Randomized multistage stratified cluster sampling from the islander population was used in a population-based case-control study. Then interview, physical examination, and ultrasonography were done.
  
  
  RESULTS
  Univariate logistic-regression analysis showed that male gender, smoking, daily alcohol intake > or =20 g, duration of drinking > or =5 years, total alcohol intake > or =36.5 kg, hypertension and obesity were closely related to fatty liver (all P<0.05). Multivariate stepwise logistic-regression analysis showed duration of drinking > or =5 years and obesity were closely related to fatty liver (both P<0.05), the odds-ratio (OR) (95% CI) was 1.954 (1.364-2.799) and 7.014 (4.919-10.002), respectively. The prevalence of fatty liver in this district was 40.0%. The prevalence of fatty liver in the non-obese and <5 years drinking group, the non-obese and > or =5 years drinking group, the obese and <5 years drinking group and the obese and > or =5 years drinking group were 15.43%, 26.73%, 56.78% and 71.52%, respectively. A dose-response relation between the duration of drinking and fatty liver was not apparent. After stratification by obesity, we found that the severity of fatty liver on ultrasonography was positively correlated with the duration of drinking level in the obese and non-obese groups, Pearson's correlation coefficients were 0.293 in the obese group and 0.178 in the non-obese group (both P<0.05).
  
  
  CONCLUSIONS
  The duration of drinking > or =5 years and obesity were two important risk factors for fatty liver in the islander population of East China. The prevalence of fatty liver in this population was high. An alcoholic threshold effect may be more important than a dose-response effect on the morbidity of fatty liver.
authors.affiliation: Department of Gastroenterology, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Dai
authors.forename: Zhe
authors.initials: Z
authors.lastname: Shen
authors.forename: Chao-Hui
authors.initials: CH
authors.lastname: Yu
authors.forename: Xi-Cheng
authors.initials: XC
authors.lastname: Zhang
authors.forename: You-Ming
authors.initials: YM
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000208:ethnology; D044466:Asian People / Q000706:statistics & numerical data; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005234:Fatty Liver / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000208:ethnology; D016017:Odds Ratio; D011159:Population Surveillance; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014463:Ultrasonography