Beneficial Effects of Insulin on Glycemic Control and β-Cell Function in Newly Diagnosed Type 2 Diabetes with Severe Hyperglycemia after Short-Term Intensive Insulin Therapy

Abstract

Objective- To evaluate whether treatment with insulin is advantageous compared with oral anti-diabetic agents in newly diagnosed type 2 diabetes with severe hyperglycemia after short-term intensive insulin therapy.

Research design and methods- Newly diagnosed type 2 diabetic patients with severe hyperglycemia were hospitalized and treated with intensive insulin injections for 10-14 days. The oral glucose tolerance test (OGTT) was performed after intensive insulin treatment. After discharge, the patients were randomized to receive either insulin injections or oral anti-diabetic drugs (OAD) for further management. The OGTT was repeated 6 months later, and the β-cell function and insulin sensitivity were evaluated again. These subjects were continually followed-up for another 6 months to evaluate their long-term glycemic control.

Results- At the 6^th month of the study, the A1C level was significantly lower in the insulin group than in the OAD group (6.33±0.70% vs. 7.50±1.50%, p=0.002). During the follow-up visit, the A1C level was still better in the insulin group (6.78±1.21% vs. 7.84±1.74%, p=0.009). All parameters regarding β-cell function measured in the OGTT were improved significantly in both groups after 6 months of treatment. Compared with the OAD group, the HOMA-beta index, insulin AUC and insulinogenic index were better in the insulin group.

Conclusions- A 6-month course of insulin therapy, compared with OAD treatment, could more effectively achieve adequate glycemic control and significant improvement of β-cell function in new-onset type 2 diabetic patients with severe hyperglycemia.