Compared to placebo, GLP-1 RAs reduced T2DM incidence (OR 0.51; 95% CI 0.28, 0.94; P-value 0.03), and 2.4 mg of semaglutide was overall effective (OR 0.38; 95% CI 0.16, 0.94; P-value < 0.0001). This evidence concerns the gene GCG and type 2 diabetes mellitus.