Arterial properties of early hypertension.

In addition to high blood pressure, hypertension is characterised by metabolic and cardiovascular abnormalities, including decreased arterial compliance. To evaluate arterial involvement in early hypertension, we have employed a technique that analyses the arterial pulse wave contour to separately quantify proximal compliance (aorta and large arteries) and distal compliance (small arteries and arterioles). Proximal compliance was 24% lower in patients with borderline (diastolic BP 90-99 mmHg, n = 22) and 33% lower in patients with established (n = 19) hypertension than in normals (n = 15); distal compliance was 58% and 61% lower. These differences were not age-dependent, for in 27 age-matched pairs, proximal and distal compliances were 22% (P less than 0.01) and 55% (P less than 0.01) lower in hypertensives (diastolic BP greater than or equal to 95 mmHg) than in normotensives. Moreover, independent of BP or age, both proximal (P less than 0.05) and distal (P less than 0.01) compliance values were significantly lower in subjects with a family history of hypertension than in those without. Proximal compliance correlated inversely with indices of BP variability and heart work measured by automated whole-day blood pressure monitoring. Thus, changes in the elastic properties of the distal arterial circulation, reflected by decreased compliance, occur at the initiation of hypertension and may be an early diagnostic marker. Low proximal compliance appears to be associated with established hypertension, and might be a determinant of cardiovascular prognosis.