Effects of Arginine and N-Acetylcysteine Administration on Nitric Oxide Production and Arterial Blood Pressure in Hypertensive Diabetic Patients.

It has been demonstrated that the nitric oxide production is reduced in type 2 diabetic patients and that cardiovascular complications represent 80% of the causes of death in these patients. As nitric oxide is able to reduce platelet aggregation, increase the relaxation of smooth muscle cells, and reduce plasminogen activator inhibitor-1 and endothelin, we hypothesized that nitric oxide deficiency is responsable for the cardiovascular disease in type 2 diabetes mellitus. Arginine and N-acetylcysteine, precursor and enhancer of the nitric oxide synthesis respectively, are able to increase nitric oxide production.

Aim of the study is to evaluate the effect of arginine and N-acetylcysteine administration on arterial blood pressure and different metabolic parameters in patients with type 2 diabetes mellitus and hypertension.

Subjects and methods. 24 male subjects, randomly divided in two groups, will be studied. These subjects will undergo a treatment with arginine (1200 mg once a day) plus N-acetylcysteine (600 mg twice a day) or placebo for six months. Basal and final evaluations include:

• general examination
• ABPM (ambulatory blood pressure monitoring)
• HbA1c, total-cholesterol, HDL-cholesterol, LDL-cholesterol, oxidized LDLs, triglycerides, reduced/oxidized glutathione ratio in red blood cells, nitrites/nitrates, asymmetrical and symmetrical dimethyl-arginine, nitrotyrosine, arginine, homocysteine, C-reactive protein, interleukin-6, tumor necrosis factor-α, intercellular and vascular-cell adhesion molecules, plasminogen activator inhibitor-1 and fibrinogen
• the ultrasound assessment of the intima-media thickness after endothelium-dependent flow-mediated vasodilation of the brachial artery

Expected results. Increase of nitric oxide production and reduction of arterial blood pressure and oxidative parameters.