Effects of insulin and exenatide therapy on glycemic control and β-cell function in patients newly diagnosed with type 2 diabetes and severe hyperglycemia

BACKGROUND: To assess the efficacy of short-term insulin therapy compared with exenatide therapy in glycemic control, remission rate, and β-cell function in patients newly diagnosed with type 2 diabetes and severe hyperglycemia. METHODS: Patients with newly diagnosed type 2 diabetes and a glycated hemoglobin (HbA1c) level >9% were treated with insulin injections for 10-14 days, after which oral glucose tolerance tests (OGTTs) were performed. The patients were randomized in an open-label design to receive either insulin therapy or exenatide therapy for a further 24 weeks. The OGTT was repeated 6 months after randomization to re-evaluate β-cell function and insulin sensitivity. The participants were followed for another year to evaluate long-term glycemic control. RESULTS: We randomized 40 patients into the insulin group (n=22) and the exenatide group (n=18). One patient in the exenatide group withdrew before the intervention, resulting in 22 and 17 patients in the insulin and exenatide groups, respectively. Body weight was significantly higher in the insulin group than in the exenatide group at baseline (75.8±14.3 vs. 60.5±12.2 kg, p=0.011). The mean HbA1c levels were similar between the insulin and exenatide groups at 6 months (6.74±1.12% vs. 6.88±0.76%, p=0.681) and 12 months after randomization (6.62±0.69% vs. 7.05±0.72%; p=0.119). By 1 year after the intervention, the remission rates were 18.2% (n=4) in the insulin group and 5.9% (n=1) in the exenatide group (p=0.025). The median time to relapse was 6.5 months in the insulin group and 5.0 months in the exenatide group (p=0.685). Compared with the exenatide group, the insulin group had better homeostasis model assessment of β-cell function index, insulinogenic index, and total insulin secretion during the OGTT. CONCLUSION: Insulin therapy may improve β-cell function and reduce remission rates compared with exenatide therapy in patients newly diagnosed with type 2 diabetes and severe hyperglycemia.