Effects of cold pressor-induced sympathetic stimulation on the mechanical properties of common carotid and femoral arteries in healthy males.

Our aim was to evaluate the effects of sympathetic excitation and elevation of blood pressure on mechanical properties of common carotid and femoral arteries by wave intensity analysis (WIA). The diameters and arterial stiffness parameters of right common carotid artery (RCCA) and right common femoral artery (RCFA) in healthy young men were measured by WIA at baseline and during cold pressor test (CPT). In addition, the blood pressure and heart rate were recorded simultaneously. The heart rates and blood pressures increased during CPT compared with baseline, while the pulse pressures remained unchanged. The diameters of RCCA increased slightly, while those of RCFA did not change. The Peterson's pressure modulus (Ep), augment index (AI), and pulse wave velocity from β (PWVβ) increased obviously, while arterial compliance (AC) decreased with no change in stiffness index (β) of both arteries during CPT when compared with baseline. There was an obvious increase in pulse wave velocity from wave intensity (PWV_WI) of RCCA, while the PWV_WI of RCFA showed no significant change during CPT. The sympathetic nervous system exerts a more marked tonic restraint on RCFA than on RCCA. The Ep, AC, AI, PWVβ of RCCA, and RCFA are much affected by variations in blood pressure and sympathetic status, while the β of both arteries are less vulnerable to these factors and are more reliable in reflecting the actual arterial stiffness; The PWV_WI appears to be suitable only for evaluating the stiffness of RCCA instead of RCFA.