Effectiveness of vildagliptin as add-on to metformin monotherapy among uncontrolled type 2 diabetes mellitus patients in a real-world setting

Background: Vildagliptin is a dipeptidyl peptidase-4 inhibitor commonly used as a dual oral agent with metformin, thiazolidinediones, or sulfonylurea for the treatment of type 2 diabetes mellitus (T2DM). The efficacy of dual therapy with vildagliptin and metformin has been established in randomized controlled trials, but there is little evidence from observational studies. The aims of the present study were to evaluate the effectiveness of vildagliptin as an add-on therapy to metformin in reducing HbA1c and its affects on body weight and blood lipids in a real-life setting. Methods: Included in the present retrospective cohort were T2DM patients (n = 345) who were uncontrolled on metformin monotherapy and intensified treatment with vildagliptin. The efficacy of at least 90 days of dual therapy with vildagliptin and metformin in reducing HbA1c levels, as well as changes in blood lipids and body weight, were evaluated. Results: After 180 days (range 90–365 days) from the index date with a mean daily dose of 92 mg vildagliptin, HbA1c was significantly (P < 0.001) reduced by an average of 0.9% (95% confidence interval −1.0%, −0.7%). The absolute reduction in HbA1c was positively associated with baseline HbA1c levels. In addition to HbA1c, a modest but significant (P < 0.05) decrement was also calculated in the patients' body weight and blood lipids. Conclusions: The present analysis of real-world data corroborates the results of previous randomized controlled trials indicating that add-on therapy with vildagliptin in uncontrolled patients on metformin monotherapy is associated with a significant improvement in the control of HbA1c.