Compared with non-diabetic MI/R (NIR) group, myocardial superoxide generation was significantly increased in diabetic MI/R (DIR) group (P < 0.01), and up-regulation of SIRT1 inhibited superoxide accumulation (Fig. 5a, n = 6, P < 0.01 vs. DIR group). Here, SIRT1 is linked to myocardial infarction.