Induction of long-term glycemic control in newly diagnosed type 2 diabetic patients is associated with improvement of beta-cell function.

To investigate whether long-term optimal glycemic control can be achieved without medication by transient continuous subcutaneous insulin infusion (CSII) and the possible mechanisms responsible for this remission. Newly diagnosed type 2 diabetic patients (n = 138, fasting glucose >11.1mmol/l) were hospitalized and treated with CSII for 2 weeks. Intravenous glucose tolerance tests (IVGTTs) were performed, and blood glucose, HbA(1c), lipid profiles, proinsulin, insulin, and C-peptide were measured before and after CSII. Patients were followed longitudinally on diet alone after withdrawal of insulin. Optimal glycemic control was achieved within 6.3 +/- 3.9 days by CSII in 126 patients. The remission rates (percentages maintaining near euglycemia) at the third, sixth, twelfth, and twenty-fourth month were 72.6, 67.0, 47.1, and 42.3%, respectively. Patients who maintained glycemic control >12 months (remission group) had greater recovery of beta-cell function than those who did not (nonremission group) when assessed immediately after CSII. Homeostasis model assessment of beta-cell function (HOMA-B) and the area under the curve (AUC) of insulin during IVGTT were higher in the remission group (145.4 +/- 89.6 vs. 78.5 +/- 68.5, P = 0.002, and 1,423.4 +/- 523.2 vs. 1,159.5 +/- 476.8 pmol x l(-1) x min(-1), P = 0.044). Change in acute insulin response was also greater in the remission group than that in the nonremission group (621.8 +/- 430.4 vs. 387.3 +/- 428.8 pmol x l(-1) x min(-1), P = 0.033). Short-term intensive insulin therapy can induce long-term glycemic control in newly diagnosed type 2 diabetic patients with severe hyperglycemia. The improvement of beta-cell function, especially the restoration of first-phase insulin secretion, could be responsible for the remission.