Effects on Clinical Outcomes of Adding Dipeptidyl Peptidase-4 Inhibitors Versus Sulfonylureas to Metformin Therapy in Patients With Type 2 Diabetes Mellitus.

BACKGROUND Recent studies concluded that dipeptidyl peptidase-4 (DPP-4) inhibitors provide glycemic control but also raised concerns about the risk for heart failure in patients with type 2 diabetes mellitus (T2DM). However, large-scale studies of the effects on cardiovascular outcomes of adding DPP-4 inhibitors versus sulfonylureas to metformin therapy remain scarce. OBJECTIVE To compare clinical outcomes of adding DPP-4 inhibitors versus sulfonylureas to metformin therapy in patients with T2DM. DESIGN Nationwide study using Taiwan's National Health Insurance Research Database. SETTING Taiwan. PATIENTS All patients with T2DM aged 20 years or older between 2009 and 2012. A total of 10,089 propensity score-matched pairs of DPP-4 inhibitor users and sulfonylurea users were examined. MEASUREMENTS Cox models with exposure to sulfonylureas and DPP-4 inhibitors included as time-varying covariates were used to compare outcomes. The following outcomes were considered: all-cause mortality, major adverse cardiovascular events (MACEs) (including ischemic stroke and myocardial infarction), hospitalization for heart failure, and hypoglycemia. Patients were followed until death or 31 December 2013. RESULTS DPP-4 inhibitors were associated with lower risks for all-cause death (hazard ratio [HR], 0.63 [95% CI, 0.55 to 0.72]), MACEs (HR, 0.68 [CI, 0.55 to 0.83]), ischemic stroke (HR, 0.64 [CI, 0.51 to 0.81]), and hypoglycemia (HR, 0.43 [CI, 0.33 to 0.56]) compared with sulfonylureas as add-on therapy to metformin but had no effect on risks for myocardial infarction and hospitalization for heart failure. LIMITATION Observational study design. CONCLUSION Compared with sulfonylureas, DPP-4 inhibitors were associated with lower risks for all-cause death, MACEs, ischemic stroke, and hypoglycemia when used as add-ons to metformin therapy. PRIMARY FUNDING SOURCE None.