Epidemiology of fatty liver in an islander population of China: a population-based case-control study.

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.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.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).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.