Background: Old obese subjects are particularly vulnerable to the complications of type 2 diabetes. Insulin resistance (IR), glucose effectiveness (GE), first and second phase insulin secretion (FPIS, SPIS) are recognized as the pathophysiological factors for inducing diabetes. In the study, we estimated IR, FPIS, SPIS and GE to determine which one contributes most for having glucose dysregulation (prediabetes and diabetes).
Materials and methods: We randomly enrolled 313 obese old women. The four factors were calculated by the equations published by our groups. The receiver operating characteristic (ROC) curve was used to calculate the area under the curve (AUC). Two models were built: Model 1: GE and FPIS and Model 2: Model 1 + SPIS.
Results: The AUC of the four factors, from the highest to the lowest are SPIS, FPIS, GE and IR (0.722, 0.683, 0.681 and 0.534, respectively). The AUC of Model 1 (FPIS and GE) was 0.732 which is higher than that of SPIS. After adding the SPIS on to model 1, the AUC of model 2 does not increase (0.731). Based on this model 1, an equation was built (p = -331✕GE - 0.003✕FPIS + 5.45). If p is equal or higher than zero (≥ 0), the subject would have higher chance to have glucose dysregulation (sensitivity = 0.699, specificity = 0.636).
Conclusion: SPIS is the most important determinate for having glucose dysregulation followed by FPIS, GE and IR in old-obese Chinese women. By building a model with GE and FPIS could only modestly increase the prediction power.