Effects of isolated systolic hypertension and essential hypertension on large and middle-sized artery compliance

Abstract

Background: Systolic hypertension of the elderly is characterized by a reduction in arterial compliance. Whether and to what extent this involves arteries of various structure and size is not well known.

Objective: To study carotid and radial artery compliance in systolic hypertension of the elderly, compared to essential hypertension and normotension.

Methods: We investigated 28 elderly patients with systolic hypertension (age 68.6 +/- 1.4 years, mean +/- SE; systolic blood pressure > 160 mmHg and diastolic blood pressure < 90 mmHg) plus 17 age-matched patients with essential hypertension and 15 age-matched healthy normotensive subjects. Radial and carotid artery compliance were evaluated using echotracking techniques. In both arteries compliance was assessed statistically and dynamically, i.e. as compliance values throughout the diasto-systolic pressure range. Measurements included intima-media wall thickness of the radial artery.

Results: Compared to normotensive subjects, carotid artery compliance was reduced in essential hypertension and more so in systolic hypertension. However, although in both groups radial artery wall thickness was markedly greater than in the normotensive group, radial artery compliance was markedly reduced in systolic hypertension, but unchanged in essential hypertension.

Conclusions: In systolic hypertension of the elderly the reduction of arterial compliance is marked in both muscular and large elastic arteries, while in elderly essential hypertensives changes in arterial compliance are more heterogeneous, i.e. only carotid artery compliance is reduced. The different effects of these two types of hypertension on arterial mechanics are visible throughout the physiological range of blood pressure and probably accounted for by different alterations in vessel wall structure.