Brachial arterial changes in response to wrist occlusion in normotensive and hypertensive men.

Diameter, blood velocity, and flow of the brachial artery and vascular resistance of the brachial circulation were evaluated with a pulsed Doppler velocimeter before and after wrist occlusion in 8 younger and 8 older normotensive subjects and in 11 younger and 11 older hypertensive patients. Before occlusion, no differences existed between younger and older normotensives. However, in hypertensives, systolic peak velocity was higher in younger than in older hypertensives (P less than 0.001) and correlated to age in the overall patients (r = -0.57, P less than 0.01). Occlusion decreased velocity and flow and increased vascular resistance in all groups, but the change in resistance was not correlated with the base-line resistance. During occlusion, no differences existed between younger and older normotensives. However, in hypertensives mean and systolic peak velocity was higher (P less than 0.01), and vascular resistance was lower (P less than 0.01) in younger than in older patients. In hypertensive patients, during occlusion mean and systolic peak velocity were negatively correlated to age (r = -0.72, P less than 0.001; r = -0.59, P less than 0.01), and vascular resistance was positively related to age (r = +0.66, P less than 0.001). Thus wrist occlusion modified the brachial circulation in normotensive and hypertensive populations but revealed age-related differences only in hypertensive patients, suggesting a combined effect of age and hypertension on the muscle vascular bed.