Meta-Analysis of Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Cardiovascular Outcomes and All-Cause Mortality Among Patients With Type 2 Diabetes Mellitus

The benefit or risk of sodium glucose cotransporter 2 (SGLT2) inhibitors on cardiovascular (CV) outcomes in patients with type 2 diabetes mellitus has not been established. We aimed to assess the comparative CV safety and mortality risk associated with the use of SGLT2 inhibitors. PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov were systematically searched up to January 27, 2016, to identify randomized controlled trials (RCTs) with the use of SGLT2 inhibitors of at least 24 weeks of duration. The primary outcomes included all-cause mortality and major adverse cardiovascular events. A random-effects network meta-analysis was performed to calculate the odds ratio (OR) with 95% CI. We identified 37 eligible trials involving 29,859 patients that compared 3 SGLT2 inhibitors (canagliflozin, dapagliflozin, and empagliflozin) to placebo and other active antidiabetic treatments. Of all direct and indirect comparisons, only empagliflozin compared with placebo was significantly associated with lower risk of all-cause mortality (OR 0.67, 95% CI 0.56 to 0.81) and major adverse cardiovascular events (OR 0.81, 95% CI 0.70 to 0.93). However, the significant effect of empagliflozin was largely driven by one large randomized trial (EMPA-REG OUTCOME trial). Neither dapagliflozin nor canagliflozin was significantly associated with any harm. In conclusion, current RCT evidence suggests that 3 common SGLT2 inhibitors are not associated with increased risk of all-cause mortality and CV outcomes when used to treat patients with type 2 diabetes mellitus. Although empagliflozin may have a protective effect, further confirmative data from rigorous RCTs are needed.