One-year real-life efficacy of sitagliptin revealed importance of concomitant pioglitazone use in Japanese patients with type 2 diabetes mellitus

SummaryAimsDipeptidyl-peptidase 4 inhibitors have become one of the most popular antidiabetic drugs. However, what kind of combinations with other drugs were advantageous was not known. Here, we tried to elucidate it in a real-life clinical setting.MethodsWe retrospectively studied efficacies of sitagliptin in 87 Japanese patients with type 2 diabetes mellitus for 52 weeks. We divided subjects into excellent, effective and unresponsive subgroups according to glycemic responses to sitagliptin.ResultsIn the excellent and effective groups the minimum HbA1c values were attained at 16 weeks while HbA1c levels in the unresponsive group kept increasing during the study period. There was a significant difference in the baseline HbA1c values between the excellent and unresponsive groups (p = 0.02). Interestingly, the mean doses of pioglitazone were highest in the excellent group and lowest in the unresponsive group (p = 0.02). When we compared the effective and unresponsive groups, the mean doses of sulfonylureas were constantly higher in the effective group than in the unresponsive group (p = 0.05).ConclusionsThese data suggest that the baseline HbA1c value can be a factor that predicts the extent of HbA1c reduction and reveal a possibility that the concomitant use of pioglitazone augments glycemic responsiveness to sitagliptin.