Prevalence and Risk Factors of Nonalcoholic Fatty Liver Disease in an Adult Population of Taiwan: Metabolic Significance of Nonalcoholic Fatty Liver Disease in Nonobese Adults

Background The prevalence of nonalcoholic fatty liver disease (NAFLD) is rarely reported in Taiwan. Goals To determine the prevalence and risk factors of NAFLD in an adult population of Taiwan. Study The cross-sectional community study examined 3245 adults in a rural village of Taiwan. The diagnostic criteria for NAFLD included no excessive alcohol intake, no chronic viral hepatitis, no known etiologies of liver disease, and ultrasonography consistent with fatty liver. Results The prevalence of NAFLD was 11.5% (372/3245). The risk factors for NAFLD in the general population were male sex [odds ratio (OR), 1.44; 95% confidence interval (CI), 1.09-1.90], elevated alanine aminotransferase (ALT) (OR, 5.66; 95% CI, 3.99-8.01), obesity (OR, 7.21; 95% CI, 5.29-9.84), fasting plasma glucose ≥126 mg/dL (OR, 2.08; 95% CI, 1.41-3.05), total cholesterol ≥240 mg/dL (OR, 1.50; 95% CI, 1.06-2.13), triglyceride ≥150 mg/dL (OR, 1.76; 95% CI, 1.32-2.35), and hyperuricemia (OR, 1.53; 95% CI, 1.16-2.01). Age ≥65 years was inversely related to NAFLD (OR, 0.53; 95% CI, 0.36-0.77). The only NAFLD risk factors among nonobese subjects were age between 40 and 64 years (OR, 2.35; 95% CI, 1.34-4.11, P=0.003), elevated ALT (OR, 15.45; 95% CI, 8.21-29.09, P<0.001), and triglyceride ≥150 mg/dL (OR, 2.48; 95% CI, 1.42-4.32, P=0.001). In subjects with NAFLD, the prevalence of elevated ALT in the presence of each metabolic risk factor, such as obesity, fasting plasma glucose ≥126 mg/dL, total cholesterol ≥240 mg/dL, triglyceride ≥150 mg/dL, and hyperuricemia, did not differ from that of subjects with normal ALT levels. Conclusions NAFLD is closely associated with elevated ALT, obesity, diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, and hyperuricemia. Among the metabolic disorders, only hypertriglyceridemia was related to NAFLD in nonobese subjects. Serum ALT level was not a good predictor of metabolic significance in subjects with NAFLD.