Therapeutic Research

Abstract

Background：To date, a step‒up strategy from regimens including a dipeptidyl peptidase‒4（DPP‒4）inhibitor has not been established. Objective：This prospective cross‒over study was conducted in order to assess the efficacy and safety of a mitiglinide/voglibose fixed‒dose combination tablet in type 2 diabetic patients whose glycemic control is not adequate with administration of a DPP‒4 inhibitor for more than three months. Methods：In 31 diabetic patients whose HbA1c was 6.9％ or higher with a DPP‒4 inhibitor, we switched their DPP‒4 inhibitor to a mitiglinide/voglibose fixed‒dose combination tablet for 3 months. Subsequently, the combination tablet was switched to the original DPP‒4 inhibitor, which was then administered for 3 months. The total observa tion period of each patient was 6 months. We evaluated the changes in HbA1c, glycoalbumin, 1,5‒anhydroglucitol （1,5‒AG）, casual blood glucose, serum C peptide, and glucagon levels. Results：Switching to the combination tablet did not change the HbA1c level but caused a reduction in glycoalbumin level and an increase in 1,5‒AG level. After the switch to the original DPP‒4 inhibitor, HbA1c and glycoalbumin levels increased, and 1,5‒AG level decreased. After the DPP‒4 inhibitor was changed to the combination tablet, casual blood glucose, serum C peptide, and glucagon did not change. After the reversal to the original DPP‒4 inhibitor, blood glucose increased, but C peptide and glucagon did not change. Conclusion：The combination tablet showed a more favorable effect on glycoalbumin and 1,5‒AG than did the DPP‒4 inhibitor. This might reflect a greater improvement of postprandial hyperglycemia by the combination tablet.