Existing research has shown that retinol binding protein(RBP4) has an impairing effect on arterial elasticity and induces insulinresistance, but the clinical value of RBP4 in patients with coronary heartdisease (CHD) combined with type 2 diabetes mellitus (T2DM) has not beeninvestigated. Here, RBP4 is linked to coronary artery disorder.