Treatment with alpha-lipoic acid reduces asymmetric dimethylarginine in patients with type 2 diabetes mellitus.

Elevated asymmetric dimethylarginine (ADMA) concentrations predict cardiovascular events in patients with type 2 diabetes mellitus (T2DM). It has been shown that alpha-lipoic acid (ALA) improves endothelial function and oxidative stress in these patients. The present study investigated if ALA reduces ADMA in patients with T2DM. Plasma concentrations of ADMA, L-arginine and symmetric dimethylarginine (SDMA) were determined in a double-blind, randomized, placebo-controlled study in patients with T2DM. Intravenous ALA (n = 16) or placebo (n = 14) was administered daily for 3 weeks. ALA reduced ADMA while no change was observed with placebo (mean change -0.05 micromol/1[95% CI: -0.01; -0.09] vs. 0.01 micromol/1 [95% CI: -0.05; -0.03]; ANOVA p = 0.031). SDMA and L-arginine were not affected by ALA. In conclusion ALA treatment reduces ADMA in patients with T2DM. Long-term studies need to demonstrate if ALA may cause cardiovascular risk reduction.