Abnormal glucose tolerance in young male patients with nonalcoholic fatty liver disease.

OBJECTIVE: The association of nonalcoholic fatty liver disease (NAFLD) with insulin resistance and metabolic syndrome has been documented for obese men and middle-aged men. This study was designed to determine the relationship between NAFLD and the oral glucose tolerance test (OGTT) to predict preclinical diabetes in nondiabetic young male patients (<30 years old).

METHODS: A total of 75 male patients who had elevated liver enzymes and who were diagnosed with NAFLD were enrolled in this study. A standard 75 g OGTT was carried out on all patients. Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were defined as a fasting plasma glucose (FPG) level > or =100 mg/dl but <126 mg/dl, and a 2-h post-load glucose on the OGTT of > or =140 mg/dl, but <200 mg/dl respectively.

RESULTS: According to the OGTT results, 24 (32%) patients were diagnosed as having IGT and 12 (16%) patients were diagnosed as having diabetes. Among the 48 patients with normal fasting glucose, 18 (37.6%) patients showed abnormal glucose tolerance (15 had IGT and three had diabetes). The NAFLD patients with abnormal glucose tolerance showed significant differences in age, weight, body mass index, waist-hip ratio, alanine aminotransferase, total bilirubin, total cholesterol, low-density lipoprotein cholesterol, triglyceride, insulin, FPG and homeostasis model for insulin resistance (HOMA-IR). Multiple regression analysis showed that age, FPG and HOMA-IR were independent predictors of abnormal glucose tolerance.

CONCLUSIONS: Although the patients were young men, an OGTT should be recommended for NAFLD patients with elevated liver enzymes and IFG to predict the risk of type 2 diabetes.