Parameters Measuring Beta-Cell Function Are Only Valuable in Diabetic Subjects with Low Body Mass Index, High Blood Glucose Level, or Long-Standing Diabetes

PURPOSE: The aim of this study was to identify the most precise and clinically practicable parameters that predict future oral hypoglycemic agent (OHA) failure in patients with type 2 diabetes, and to determine whether these parameters are valuable in various subgroups. MATERIALS AND METHODS: We took fasting blood samples from 231 patients for laboratory data and standard breakfast tests for evaluation of pancreatic beta-cell function. Hemoglobin A1c (HbA1c) levels were tested, and we collected data related to hypoglycemic medications one year from the start date of the study. RESULTS: Fasting C-peptide, postprandial insulin and C-peptide, the difference between fasting and postprandial insulin, fasting beta-cell responsiveness (M0), postprandial beta-cell responsiveness (M1), and homeostasis model assessment-beta (HOMA-B) levels were significantly higher in those with OHA response than in those with OHA failure. The area under the curve (AUC) of the receiver operating characteristic (ROC) measured with postprandial C-peptide to predict future OHA failure was 0.720, and the predictive power for future OHA failure was the highest of the variable parameters. Fasting and postprandial C-peptide, M0, and M1 levels were the only differences between those with OHA response and those with OHA failure among diabetic subjects with low body mass index, high blood glucose level, or long-standing diabetes. CONCLUSION: In conclusion, postprandial C-peptide was most useful in predicting future OHA failure in type 2 diabetic subjects. However, these parameters measuring beta-cell function are only valuable in diabetic subjects with low body mass index, high blood glucose level, or long-standing diabetes.