Impact of therapy with alpha-lipoic acid (ALA) on the oxidative stress in the controlled NIDDM: a possible preventive way against the organ dysfunction?

There is a growing evidence that excess generation of highly reactive free radicals, largely due to hyperglycemia, causes oxidative stress, which further exacerbates the development and progression of diabetes and its complications. The purpose of this study was to evaluate the impact of ALA on lipid profile, oxidative pattern and inflammation in patients with controlled non-insulin dependent diabetes mellitus (NIDDM). ALA, 400mg/day was investigated in NIDDM patients over a period of 4 weeks using a randomized, placebo-(PLA)-controlled study with two parallel groups. The marker of oxidative stress was the concentration of reactive oxygen metabolites, evaluated using a commercially available test, called d-ROMs test, and the biological antioxidant potential (BAP); besides, the lipid profile (total cholesterol=TC, high-density lipoprotein-cholesterol = HDL-C; low-density lipoprotein-cholesterol=LDL-C, and triglycerides=TG) and the C-reactive protein (CRP), marker of inflammation were measured at the beginning and at the end of the treatment. A total of 14 patients were randomly assigned to the two groups. ALA was safe and well tolerated in the only oral daily administration. The d-ROMs test (p=0.03) and HDL-C (p=0.04) showed a significant difference between the two groups. BAP (p=0.06) tended to be higher in the treated patients, while LDL-C (p=0.07) presented a moderate decline. There were no significant differences in TC (p=0.65), TG (p=0.78) and CRP (p=0.96) between the ALA and PLA groups. ALA therapy appears to reduce significantly d-ROMs and to improve HDL-C value, especially in men with metabolic syndrome treated with oral hypoglycemic drugs. These findings will be useful in patient selection in future clinical trials with ALA in long term studies.