Aim: To assess insulin secretion/insulin resistance index in predicting the risk for future T2DM Experimental Design and Methods: 1551 non-diabetic subjects from the San Antonio Heart Study received an OGTT with measurement of plasma glucose and insulin

Aim: To assess insulin secretion/insulin resistance index in predicting the risk for future T2DM Experimental Design and Methods: 1551 non-diabetic subjects from the San Antonio Heart Study received an OGTT with measurement of plasma glucose and insulin concentrations at 0, 30, 60, and 120 minutes at baseline and after 7-8 years of follow-up. Insulin secretion/insulin resistance index was calculated as the product of Matsuda index and ∆I0-30/∆G0-30 or ∆I0-120/∆G0-120. The discriminatory power of various prediction models for development of T2DM was tested with the area under the receiver-operating characteristics (ROC) curve. Results: Insulin secretion/insulin resistance index (0-30 and 0-120 min time periods) had the greatest areas under ROC (0.85 and 0.86, respectively), which were significantly greater than the 2-h plasma glucose concentration during the OGTT or The San Antonio Diabetes Prediction Model (SADPM) (P<0.001 and P<0.0001, respectively). A model based on the combination of the SADPM model and a modified version of the insulin secretion/insulin resistance index or 1-h plasma glucose concentration had equal power to predict the risk for future T2DM compared to the insulin secretion/insulin resistance index. Conclusion: The insulin secretion/insulin resistance index is useful as a predictor of future development of T2DM. A model based upon the combination of the SADPM model and either a modified version of the insulin secretion/insulin resistance index or 1hour plasma glucose concentration can equally predict future T2DM.