Endocrine Abstracts

The pathogenesis of type 2 diabetes is explained by increment of insulin resistance and dysfunction of insulin secretion. If improvement of insulin resistance is not adequate in the early stage of diabetes especially in this country with more severe basal insulin secretion defect from the very beginning, diabetes rapidly progress to more aggressive stage with relative insulin deficiency. The most proper method of improving insulin resistance by prescription is metformin from the first and adding TZD class in terms of improvement of insulin resistance when the target of glucose control doesn’t reach by metformin alone. The next step when the target of glucose control doesn’t reach by improving insulin resistance prescription with metformin and TZD is not certain. Adding the other prescription that has different action or insulin is one of options and it is determined by degree of glucose control, insulin secretory capacity of β cell or economic status of patient in practice. The DPP-4 inhibitors that increase insulin secretion by glucose dependent manner also relieve insulin resistance because they improve first phase insulin secretion defect and prevent late hyperinsulinemia. When we can’t reach the target below 7% of HgA1c with metformin plus TZD combination that is best in terms of relieving insulin resistance in early diabetes, switching the TZD to the DPP-4 inhibitors that improve insulin secretory dysfunction can be the next useful step to attain glucose control goal. So we compared the effect of glucose control when we switched the TZD to the DPP-4 inhibitor in patients who can’t reach the HgA1c below 7.0% with metformin plus TZD. We also observed the change of insulin resistance index HOMA-IR and β cell function index HOMA-βCF between treatments. Total 84 patients were enrolled and mean age was 53±11. The decrement of HgA1c 6 months after switching was 0.47±0.61. Homa-IR was improved in 57% and mean change was −0.24±0.97. HOMA-βCF was increased in 43% and mean change was −2.7±11.6. So metformin plus DPP-4 inhibitor can be a good treatment option in improving insulin resistance as well as glucose control as compared to Metformin plus TZD therapy.