Fig. 6

a Forest plot of mean difference of LVEF% among patients with metformin therapy vs no-metformin therapy. b Forest plot of mean difference of CK-MB among patients with metformin therapy vs no-metformin therapy. c Forest plot of mean difference of BNP among patients with metformin therapy vs no-metformin therapy. d Forest plot of mean difference of LDL among patients with metformin therapy vs no-metformin therapy