BACKGROUNS : Volume supplementation by normal saline infusion combined with antioxidant agents, such as N-acetylcysteine, sodium bicarbonate or ascorbic acid, represents an effective strategy to prevent contrast agent-induced nephrotoxicity (CIN). 慣-lipoic Acid, cofactor of mitochondria respiratory enzyme, is powerful anti-oxidant agent that reactive oxygen species remove. We undertook randamized controlled trial of alpha-lipoic acid for prevention of CIN in patients with impaired renal dysfunction undergoing invasive coronary procedure. METHODS: Sixty consecutive patients with renal dysfunction, referred to our institutions for coronary procedures, were randomly assigned to prophylactic administration of 0.9% saline infusion plus 慣-lipoic Acid 1,800mg (Group I, n=30), and 0.9% saline plus placebo (Group II, n=30). All enrolled patients had serum creatinine (Cr) > 1.3 mg/dL and/or estimated glomerular filtration rate < 60 mL/min/1.73m2. The primary end point was an increase of ��� 25% and/or absolute increase of ��� 0.5mg/dL in the Cr concentration 48 hours after the procedure (CIN). RESULTS: Baseline clinical characteristics such as age, sex, clinical diagnosis, medication, risk factor were similar in the 2 groups. In all cases, iodixanol (an iso-osmolar, nonionic contrast agent) was administered. The amount of contrast media administered (119.1짹90.9 and 118.1짹83.7 mL, respectively; P=NS). Baseline serum Cr level was 1.57 and 1.55 mg/dL, and Post-procedure Cr level were 1.45 and 1.45 mg/dL, respectively(P=NS). Absolute serum Cr change was -0.09짹0.14 and -0.08짹0.12 mg/dL, respectively,(P=NS). CIN occurred in 1 of 30 patients (3.3%) in the alpha-lipoic acid group, in 1 of 30 (3.3%) in the placebo group (P=NS). CONCLUSIONS: The strategy of saline supplementation by alpha-lipoic acid seems to not be superior to the full saline supplement alone in preventing CIN in renal dysfunction patients.