EVIDENCE FOR IN-VIVO CAROTID AND FEMORAL WALL THICKENING IN HUMAN HYPERTENSION

Little is known of the in vivo structural changes of large arteries in uncomplicated hypertension. Therefore, we measured the intima-media thickness and lumen diameter of common carotid and femoral arteries by a computerized ultrasonographic technique in 25 normotensive and 25 never treated hypertensive men of similar age (from 25 to 72 years). The intraobserver variability of carotid and femoral wall thicknesses was 4.3% and 5.6%, respectively. Moreover, an in vitro study of 13 human arterial segments removed at autopsy demonstrated a strong correlation (r=.989, P<.001) between computerized ultrasonic and histological intima-media thickness measurements. Compared with control subjects, hypertensive patients had similar arterial diameters but higher carotid and femoral intima-media thicknesses (P<.001) as well as higher ratios of carotid and femoral intima-media thickness to lumen (P<.001, P<.01). The carotid thickness was correlated with age in control subjects (r=.48, P<.05) but not in hypertensive patients. The femoral thickness was correlated with age both in control subjects (r=.55, P<.01) and in hypertensive patients (r=.46, P<.05). Thus, carotid and femoral arterial walls of hypertensive patients were thickened. This thickening was not due to age, although aging also thickened both vessels in control subjects and the femoral artery only in hypertensive patients. Such a wall thickening associated with a normal diameter provides direct evidence of vascular growth and represents a new target to monitor noninvasively in vivo for large artery changes in human hypertension.