Effects of stimulation of nitric oxide synthesis on large artery stiffness in patients with peripheral arterial disease.

The role of endothelium-derived nitric oxide (NO) in modulation of large artery stiffness in patients with peripheral arterial disease (PAD) is unexplored. The aim of this study was to evaluate, using pulse wave analysis (PWA), changes in aortic and systemic arterial stiffness following administration of nitroglycerin and beta(2)-agonist salbutamol in PAD patients (n = 24) and in healthy controls (n = 24). Changes in estimated aortic pulse wave velocity (T(r)) and in augmentation index (AIx), following administration of nitroglycerin and salbutamol, were assessed using PWA. Salbutamol-induced changes in T(r) and in AIx were significantly reduced in PAD patients (P < 0.001 and < 0.001, respectively), while nitroglycerin-produced changes were not different (P = 0.25 and 0.35, respectively). Changes in T(r) after salbutamol administration were independent of changes in mean arterial pressure (MAP) (R = -0.21, P = 0.16). This study shows that stimulation of NO synthesis fails to modify stiffness of the large arteries in PAD patients and changes in aortic stiffness are independent of changes in MAP. Our data support the utility of PWA as a non-invasive method for assessment of NO-mediated vascular changes.