SIRT1 and diabetes mellitus: LIMA tissues obtained from diabetic patients with coronary artery disease displayed lower SIRT1 levels than those from non-diabetic patients [3.99 (2.63–6.84) vs. 7.87 (5.49–12.1), P = 0.0064], indicating a strong association of diminished vascular SIRT1 levels with diabetes and diabetic vascular dysfunction (Figure 1A).