Therapeutic Research

Abstract

Objectives：We evaluated the effectiveness of a dipeptidyl peptidase‒4 inhibitor （DPP‒4i）as add‒on therapy to metformin and of dose‒escalation of metformin in Japanese patients with type 2 diabetes mellitus（T2DM）prescribed metformin （500 mg/day） using a real‒world clinical database. Methods：Data of T2DM patients were extracted from the health insurance administrative claims database of Medical Data Vision Company based on continued treatment with metformin 500 mg/day for ≧3 months. The first analysis cohort was“DPP‒4i add‒on”that was composed of the patients who initiated a DPP‒4i as add‒on therapy to metformin for ≧12 month. The second cohort was“metformin dose escalation”that was composed of patients treated with escalated dose of metformin（＞500 mg/day）after ≧12 month without a DPP‒4i. The changes of HbA1c levels from baseline were assessed over 12 months in the cohorts. Results：For the DPP‒4i add‒on cohort（n＝689）, the changes in HbA1c levels, mean±SD（n）, at 3, 6 and 12 months and over the evaluation period were －0.3 ±0.8％ （650）, －0.3±0.8％（621）, －0.2±0.9％（577）and －0.2±0.9％（689）, respectively, and for the metformin dose‒escalation cohort（n＝1194）, －0.2 ±0.9％（1124）, －0.3± 0.9％（1081）, －0.3±0.9％（1008）and －0.3±0.9％（1194）, respectively. All the changes were statistically significant（p＜0.0001）. Subgroup analysis of the metformin dose‒escalation cohort revealed that 1000 mg/day, but not 750 mg/day, of metformin monotherapy was effective. Conclusions：These results indicate that the DPP‒4i add‒on and metformin dose‒escalation（1000 mg/day）in Japanese T2DM patients were effective in controlling blood glucose levels in real‒world clinical practice settings.