Mounting evidence suggests that a correlation exists between nonalcoholic fatty liver disease (NAFLD) and insulin resistance and metabolic syndrome. This association has been well demonstrated in obese men and middle-aged men. The current study was conducted to estimate the interrelationship between NAFLD and the oral glucose tolerance test (OGTT) to predict preclinical diabetes in nondiabetic young male patients (<30 years old).

The study included a total of 75 male patients, diagnosed with NAFLD. All of them had elevated liver enzymes and undergone a standard 75 g OGTT. Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were defined as a fasting plasma glucose (FPG) level ≥100 mg/dl but <126 mg/dl, and a 2-h post-load glucose on the OGTT of ≥140 mg/dl, but <200 mg/dl respectively.

The outcome according to the OGTT results, demonstrated that 24 (32%) patients were diagnosed as having IGT and 12 (16%) patients were diagnosed as having diabetes. Out of the total 48 patients with normal fasting glucose, 18 (37.6%) patients exhibited abnormal glucose tolerance (15 had IGT and three had diabetes). The NAFLD patients with abnormal glucose tolerance reported remarkable variations 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). Age, FPG and HOMA-IR were found to be independent predictors of abnormal glucose tolerance, when assessed by multiple regression analysis.

Thus, the study concluded that an OGTT should be advised for NAFLD patients with elevated liver enzymes, even in young men. Moreover, IFG should be done in these young patients to predict the risk of type 2 diabetes.

Source: Liver Int. 2009;29(4):525-529.