The HRs for DPP-4 inhibitors vs. metformin were 1.01 (95% CI: 0.84–1.20) for major cardiovascular events, 0.89 (95% CI: 0.68–1.16) for myocardial infarction, 1.11 (95% CI: 0.94–1.31) for heart failure, 1.12 (95% CI: 0.89–1.40) for a stroke, and 1.06 (95% CI: 0.93–1.21) for all cardiovascular events (Figure 3). This evidence concerns the gene DPP4 and stroke disorder.