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

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.

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 ~ 1.62) when comparing the treatment group with insulin at baseline with the treatment group of patients without insulin use.

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.