Predictive clinical characteristics for the efficacy of vildagliptin monotherapy in Japanese patients with type 2 diabetes mellitus: a multicenter study

Aim Our purpose was to clarify the predictive clinical characteristics for monotherapy efficacy using a dipeptidyl peptidase-4 inhibitor, vildagliptin, in Japanese patients with type 2 diabetes mellitus (T2DM), particularly those with elevated blood glucagon. Methods The study included 72 T2DM outpatients aged 20–85 years from multiple institutions who had hemoglobin A1c (HbA1c) levels ranging from 6.9 to 9.4 %; were drug-naïve or receiving antidiabetic agent(s) orally, excluding sulfonylurea; and were not receiving insulin or a glucagon-like peptide 1 analog. Patients were orally administered 50 mg of vildagliptin instead of any previously used antidiabetic agent(s). After 8 weeks, those with HbA1c levels <6.8 % continued therapy, whereas those with HbA1c levels >6.9 % were administered 100 mg of vildagliptin for 8 more weeks. We compared several clinical characteristics of the participants, including blood glucagon level, before and after 16 weeks. Results Vildagliptin monotherapy reduced body weight and improved hyperglycemia, insulin resistance, and hypertriglyceridemia. Changing the therapy from sitagliptin to vildagliptin (27 participants) also improved hyperglycemia, insulin resistance, and blood glucagon levels. Compared with nonresponders (30 participants), responders (42 participants), who exhibited >0.5 % reduction in HbA1c levels had a significantly shorter duration of diabetes, lower number of medicines used prior to the study, higher HbA1c levels, and higher blood glucagon levels. Conclusions Our study indicates that vildagliptin monotherapy is effective in T2DM patients who have a short duration of diabetes, high HbA1c and blood glucagon levels, and require a low number of orally administered diabetic medicine(s).