Effects of α-Lipoic Acid on the Plasma Levels of Asymmetric Dimethylarginine in Diabetic End-Stage Renal Disease Patients on Hemodialysis: A Pilot Study

BACKGROUND/AIM: Endothelial dysfunction due to reduced nitric oxide (NO) availability precedes the development of atherosclerosis. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, is not only a cause of endothelial dysfunction, but also a predictor of the cardiovascular outcome in end-stage renal disease (ESRD) patients on hemodialysis (HD). Alpha-lipoic acid (ALA), a strong antioxidant, increases NO-mediated vasodilation in diabetic patients. We investigated whether ALA could decrease the plasma level of ADMA in diabetic ESRD patients on HD. METHODS: Fifty patients undergoing HD three times per week were randomized to a treatment group receiving ALA 600 mg/day for 12 weeks or a control group. We measured the plasma levels of cholesterol, albumin, high-sensitivity C-reactive protein, oxidized low-density lipoprotein, hemoglobin A1c, and ADMA in both groups at baseline and at 12 weeks. RESULTS: In the control group, the levels of total cholesterol, serum albumin, high-sensitivity C-reactive protein, oxidized low-density lipoprotein, hemoglobin A1c, and ADMA did not change. In the treatment group, the plasma levels of ADMA decreased significantly from a median of 1.68 (range 0.45-3.78) microM to a median of 1.31 (range 0.25-3.19) microM (p = 0.001). CONCLUSION: Considering that ADMA is an independent risk factor for cardiovascular outcome in ESRD patients, ALA may have the potential of a beneficial effect in them, in part by decreasing the plasma level of ADMA.