Peripheral vascular changes and ambulatory blood pressure profiles.

This study aimed to correlate blood pressure (BP) level assessed either by casual or by 24-h ambulatory BP monitoring and regional (calf and finger) blood flow and associated vascular resistance in subjects with low, intermediate, and high BP. In 75 subjects covering the range from low BP to normo- and hypertension, blood flow at calf and finger vessels were simultaneously measured using an ECG-triggered venous occlusion plethysmograph. Correlations were calculated between regional blood flow or vascular resistance and BP defined from casual and from 24-h ambulatory BP registrations, at rest, and after 3 min of arterial occlusion (reactive hyperemia). Correlations over the whole BP range, between calf and finger vascular resistances and BP, were highly significant both for casual (0.650 < r < 0.776) and for ambulatory (0.531 < r < 0.781) BP. The relations remained significant after adjustment for the age dependency of the blood pressure. At any BP level skin (finger) blood flow at rest and after arterial occlusion was higher than muscle (calf) blood flow. These data indicate that there is a progressive decrease in vasodilating capacity from low to high BP in both muscle and skin vessels. However, in the zone of borderline to moderate essential hypertensives, blood flow after 3 min arterial occlusion was already significantly decreased in the muscle circulation when compared to normotensives, while still maintained in the skin circulation.