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 t hickness and lumen diameter of common carotid and femoral arteries by a computerized ultrasonographic technique in 25 normotensive and 25 ne ver 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 int ima-media thickness measurements. Compared with control subjects, hype rtensive patients had similar arterial diameters but higher carotid an d femoral intima-media thicknesses (P<.001) as well as higher ratios o f 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 wa s correlated with age both in control subjects (r=.55, P<.01) and in h ypertensive patients (r=.46, P<.05). Thus, carotid and femoral arteria l walls of hypertensive patients were thickened. This thickening was n ot due to age, although aging also thickened both vessels in control s ubjects and the femoral artery only in hypertensive patients. Such a w all thickening associated with a normal diameter provides direct evide nce of vascular growth and represents a new target to monitor noninvas ively in vivo for large artery changes in human hypertension.