CST3 and Renal insufficiency: In this study we assessed the association between cystatin C and asymptomatic CAD in a consecutive series of MetS patients with normal kidney function in order to avoid the well-known effect of overt renal insufficiency on coronary atherosclerosis, and evaluate whether cystatin C has an ability to identify individuals at a higher risk for CAD among patients belonging to a low-risk category according to eGFR.