Contrast-induced acute kidney injury (CIAKI) is a major complication with adverse outcomes after contrast media injection. Although the risk of developing CIAKI is low in patients with normal renal function, it is dramatically higher in patients with conditions such as diabetes mellitus (DM) or chronic kidney disease (CKD). More recently, our data showed that contrast agents can induce endothelial dysfunction partially via free radicals in diabetes. Therefore, strategies to prevent CIAKI and endothelial dysfunction in DM patients with CKD are urgently needed. Alpha-lipoic acid and its reduced form, dihydrolipoate, are potent antioxidants. We hypothesized that alpha lipoic acid can prevent the contrast-induced acute kidney injury and endothelial dysfunction in type 2 diabetes.