The Association Between Baseline Insulin Treatment and Cardiovascular Events: A Meta-Analysis

Objective: We conducted a meta-analysis to compare major adverse cardiovascular events (MACEs) in recent diabetes type 2 drugs cardiovascular outcome trials (CVOTs) in the subgroups that used insulin at baseline to the subgroups that did not. Methods: English publications from 2010 to 2019 were searched in PubMed and Google Scholar. We searched published clinical trials for CVOTs with new drugs for type 2 diabetes and found 12 publications, of which 8 provided outcomes according to insulin use. We compared the event rate of the primary outcome in the group taking insulin with the one not taking insulin. Data were extracted by 2 investigators independently, including CVOT drug, publication year, sample size, duration of diabetes, mean glycated hemoglobin A 1c, mean age, and number of patients in each treatment group. We included 8 trials in the analysis: DECLARE, EMPA-REG, EXSCEL, HARMONY, LEADER, SUSTAIN-6, EXAMINE, and SAVOR-TIMI. The pooled relative risk was 1.52 (95% CI, 1.43 similar to 1.62) when comparing the treatment group with insulin at baseline with the treatment group of patients without insulin use. Results: In recent CVOTs, patients on insulin regimen along with the new antidiabetic drug had a higher risk ratio of cardiovascular events than patients who used the new antidiabetic drug alone.