Insulin Secretion Predicts the Response to Antidiabetic Therapy in Patients With New Onset Diabetes

Aim To identify predictors for individualization of antidiabetic therapy in patients with new onset T2DM. Research Design and Methods 261 drug naïve participants in the EDICT study, with new onset diabetes, were randomized in a single-center study to receive: (1) metformin followed by glipizide and then insulin glargine upon failure to achieve HbA1c <6.5%, or (2) initial triple therapy with metformin/pioglitazone/ exenatide. Each patient received 75-gram OGTT prior to start of therapy. Factors that predicted response to therapy were identified using the aROC method. Results 39 patients started and maintained the treatment goal (HbA1c <6.5%) on metformin only, and did not require intensification of antihyperglycemic therapy; 54 patients required addition of glipizide to metformin; and 47 patients required insulin addition to metformin plus glipizide for glucose control. The C-Pep120/C-Pep0 ratio during the OGTT was the strongest predictor of response to therapy. Patients with ratio <1.78 were more likely to require insulin for glucose control, while patients with ratio >2.65 were more likely to achieve glucose control with metformin monotherapy. In patients started on initial Triple Therapy the HbA1c decreased independent of C-Pep120/C-Pep0 ratio. Conclusion The increase in plasma C-peptide concentration above fasting following glucose load predicts the response to antihyperglycemic therapy in patients with new onset diabetes. C-Pep120/C-Pep0 provides a useful tool for individualization of antihyperglycemic therapy in patients with new onset diabetes.