Comparative cardiovascular outcomes in the era of novel anti-diabetic agents: a comprehensive network meta-analysis of 166,371 participants from 170 randomized controlled trials

Background: Cardiovascular (CV) safety of one anti-diabetic medication over another remains partially delineated. We sought to assess the comparative effect on CV outcomes among novel anti-diabetic agents. Methods: This study was registered with the International Prospective Register of Systematic Reviews (CRD 42016042063). MEDLINE, EMBASE, and Cochrane Library Central Register of Controlled Trials were searched between Jan 1, 1980, and June 30, 2016. Randomized controlled trials comparing anti-diabetic drugs with other comparators in adults with type 2 diabetes were included. We used network meta-analysis to obtain estimates for the outcomes of interests. In addition, post hoc correlation analysis of severe hypoglycemia and primary outcome as per ranking order was conducted. Outcomes were major adverse cardiovascular events (MACE) and all-cause mortality. Results: A total of 170 trials (166,371 participants) were included. By class and by individual, sulfonylureas (SU) ranked last. Therefore, with SU as reference, categorically sodium-glucose co-transporter 2 inhibitor (SGLT2i), insulin (INS), glucagon-like peptide-1 receptor agonist, and dipeptidyl peptidase 4 inhibitor were significantly superior in term of MACE; as were SGLT2i and INS in term of all-cause mortality. Moreover, ranking orders of MACE and all-cause mortality were both positively correlated with that of severe hypoglycemia risk (by individual: R-2 = 0.3178, P = 0.018; by class: R-2 = 0.2574, P = 0.038). Conclusions: Novel anti-diabetic agents possess favorable CV safety profile, despite small but robust differences between individuals. In addition, increase in CV risk was again shown to be partly attributable to a concomitant increase in the risk of severe hypoglycemia, for which SU performed the worst.