Effects of glucagon-like peptide-1 receptor agonists on cardiovascular risk: a meta-analysis of randomized clinical trials.

AIMS: New drugs for type 2 diabetes need to demonstrate their cardiovascular safety, due regulatory requirements from the Food and Drug Administration. For this reason, glucagon-like peptide-1 receptor agonists (GLP-1 RA) are currently undergoing large-scale, long-term randomized trials specifically designed for cardiovascular outcomes. Aim of the present meta-analysis of randomized clinical trials is the assessment of the effects of GLP-1 RA on major cardiovascular events (MACE), mortality and cardiovascular risk factors. METHODS: A meta-analysis was performed including all trials with a duration of at least 6 months, comparing a GLP-1 RA with a non-GLP-1 RA agent in type 2 diabetes. MACE and mortality were retrieved and combined to calculate Mantel-Haenzel odds ratio (MH-OR). Furthermore, data on endpoint systolic and diastolic blood pressure, total and high-density lipoprotein (HDL) cholesterol and triglyceride were collected. RESULTS: Of 37 selected trials, 33 reported information on MACE, and 25 reported at least one event. The difference in the incidence of MACE between GLP-1 RA and comparators did not reach statistical significance [MH-OR 0.78 (0.54-1.13), p = 0.18]. GLP-1 RA were associated with a significant reduction in the incidence of MACE in comparisons with placebo and pioglitazone, with a non-significant trend towards reduction in DPP4i-controlled studies. No significant effect of GLP-1 RA was observed on mortality, although a non-significant favourable trend was observed in comparisons with placebo. CONCLUSIONS: The present meta-analysis confirms the cardiovascular safety of GLP-1 RA, at least in the short term and in low-risk individuals. GLP-1 RA could have a beneficial effect on the incidence of MACE, at least in comparison with placebo.