β-cell function and long-term glycemic control in patients newly diagnosed with type 2 diabetes with moderate hyperglycemia after a 6-month course of basal insulin therapy

Aims

To evaluate whether treatment with insulin is advantageous compared with oral anti-diabetic drugs (OAD) for patients newly diagnosed with type 2 diabetes with moderate hyperglycemia.

Methods

Patients newly diagnosed with type 2 diabetes with moderate hyperglycemia were recruited and randomized to receive insulin, metformin or sitagliptin treatment. The oral glucose tolerance test (OGTT) was performed before treatment and 6 months thereafter. The primary outcome was the glycohemoglobin (HbA1c) level change. For the secondary efficacy analysis, the β-cell function and insulin sensitivity were calculated from the OGTT, as was the proportion of subjects who reached the treatment target (HbA1c level < 7.0 % or < 6.5 %) at 6 months.

Results

We randomized 50 patients to the three groups and 32 patients who received the allocated treatment were analyzed. The change of HbA1c level in the insulin, metformin, and sitagliptin groups was − 2.06 ± 1.37 %, −0.43 ± 0.32 %, and − 1.62 ± 0.92 %, respectively. This change was smallest in the metformin group. There was no significant difference in the changes or final HbA1c levels between the insulin and sitagliptin groups. The treat-to-target (HbA1c level < 7.0 %) rates in the insulin, metformin and sitagliptin were 75 %, 50 % and 100 %, respectively. The treat-to-target rates were not significantly different among the three groups. The insulin secretion indices, including the Matsuda index and HOMA-IR, indicated that the groups did not differ after 6 months of therapy.

Conclusion

A 6-month course of basal insulin therapy did not benefit patients newly diagnosed with diabetes with moderate hyperglycemia in terms of insulin sensitivity or insulin secretion.