Pioglitazone and cardiovascular outcomes in patients with insulin resistance, pre-diabetes and type 2 diabetes: a systematic review and meta-analysis

OBJECTIVES: To evaluate the effect of pioglitazone in people with insulin resistance, pre-diabetes and type 2 diabetes. DESIGN AND SETTING: Systematic review and meta-analysis of randomised, controlled trials. DATA SOURCES: Literature searches were performed across PubMed, EMBASE, MEDLINE and Cochrane Central Register of Controlled Trials from 1966 to May 2016 to identify randomised, controlled trials with more than 1 year follow-up. OUTCOME MEASURES: Relative risk (RR) with 95% CI was used to evaluate the association between pioglitazone and the risk of major adverse cardiovascular events (MACE: composite of non-fatal myocardial infarction, non-fatal stroke and cardiovascular death) and safety outcomes, after pooling data across trials in a fixed-effects model. RESULTS: Nine trials with 12 026 participants were enrolled in the current meta-analysis. Pioglitazone therapy was associated with a lower risk of MACE in patients with pre-diabetes or insulin resistance (RR 0.77, 95% CI 0.64 to 0.93), and diabetes (RR 0.83, 95% CI 0.72 to 0.97). Risks of heart failure (RR 1.32; CI 1.14 to 1.54), bone fracture (RR 1.52, 95% CI 1.17 to 1.99), oedema (RR, 1.63; CI 1.52 to 1.75) and weight gain (RR 1.60; CI 1.50 to 1.72) increased in pioglitazone group. CONCLUSIONS: Pioglitazone was associated with reduced risk of MACE in people with insulin resistance, pre-diabetes and diabetes mellitus. However, the risks of heart failure, bone fracture, oedema and weight gain were increased.