Abstract: ObjectiveTo estimate the prevalence of non-alcoholic fatty liver disease(NAFLD)and to identify the risk factors associated with the disease in middle-aged and elderly population in Lanzhou city.MethodsThis cross-sectional study included 3 183 people aged 40-75 years in a community.All participants were surveyed with a questionnaire about detailed medical history,anthropometric measurement,biochemical testing,and abdominal ultrasonography.ResultsThe prevalence(standardized prevalence)of NAFLD was 25.5%(22.9%)in the population and the prevalence in the females was significantly higher than that in the males(27.0% vs. 21.8%,P<0.01),particularly for the elderly subgroup.The prevalence of NAFLD in the females and in the males less than 60 years old increased with age.In both males and females,the incidences of overweight,obesity,diabetes mellitus,dyslipidemia,and hypertension were significantly higher in the participants with NAFLD than those without NAFLD(P<0.001);and the fasting plasma glucose(FPG),postprandial 2 hours plasma glucose(2 hPG),glycol-hemoglobin A1c(HbA₁c),body mass index(BMI),waist circumference,waist-to-hip ratio,triglyceride,total cholesterol,and systolic blood pressure,diastolic blood pressure,and liver enzyme were significantly increased and high-density lipoprotein-cholesterol decreased in NAFLD group compared with those without NAFLD(P<0.05 or P<0.01).Logistic regression analyses showed that BMI,triglyceride,HbA₁c,waist-to-hip ratio were risk factors for NAFLD in the males and females;waist circumference,FPG and 2 hPG were risk factors for NAFLD only in the females.ConclusionThe prevalence of NAFLD is about 25% in middle-aged and elderly people in Lanzhou city.Obesity,hypertriglyceridemia,high HbA₁c,and waist-to-hip ratio are associated with an increased risk of NAFLD.