No increased risk of cardiovascular events in older adults initiating dipeptidyl peptidase-4 inhibitors vs therapeutic alternatives

Abstract

Aim: To compare the cardiovascular (CV) risk associated with dipeptidyl peptidase-4 (DPP-4) inhibitors relative to sulphonylureas (SUs) and thiazolidinediones (TZDs).

Methods: During 2007 to 2013, using Medicare data for beneficiaries aged >65 years, we identified the following 2 cohorts of new-users, who had not been exposed to the drugs being compared in the 6 months before initiation: (1) DPP-4 inhibitor vs SU initiators and (2) DPP-4 inhibitor vs TZD initiators. Using propensity-score-adjusted Cox models accounting for competing risk by death, we estimated the hazard ratios (HRs), risk differences and 95% confidence intervals (CIs) for myocardial infarction (MI), stroke, hospitalization for heart failure (HF), and a combined outcome (MI, stroke, all-cause mortality).

Results: In the DPP-4 inhibitor vs SU comparison, there were 30 130 DPP-4 inhibitor initiators and 68 382 SU initiators. Their mean age was 75 years, 41% were men and 55% had a baseline CV condition. The HR for the composite outcome was 0.75 (95% CI 0.72-0.79) over a median treatment duration of 1 year, but the 1-year risks of MI were 1.00 (95% CI 0.89-1.12) and 1.47 (95% CI 1.38-1.56) per 100 patients for DPP-4 inhibitors and SUs, respectively, and the corresponding stroke risks were 0.98 (95% CI 0.87-1.10) and 1.09 (95% CI 1.01-1.17). For the DPP-4 inhibitor vs TZD comparison, there were 20 596 DPP-4 inhibitor initiators and 13 526 TZD initiators without previous HF. Their mean age was 74 years, 42% were men and 30% had a baseline CV event. The composite outcome HR was 0.94 (95% CI 0.86-1.02) over a median treatment duration of 1 year. The 1-year risk for MI was ~0.90 and for stroke it was ~0.80 per 100 patients in both DPP-4 inhibitor and TZD initiators.

Conclusion: Although limited by the short treatment period, the present study suggests there is no increased short-term risk of MI, stroke or HF with DPP-4 inhibitors vs SUs/TZDs.

Keywords: DPP-4 inhibitor; antidiabetic drug; database research; incretins; observational study; pharmaco-epidemiology.