Carotid intimal-medial thickness and stiffness are not affected by hypercholesterolemia in uncomplicated essential hypertension
The combined effects of hypertension and hypercholesterolemia on carotid anatomy and stiffness were studied in 62 normotensives, 141 uncomplicated essential hypertensives with a total cholesterol level <240 mg/dL, and 60 essential hypertensives with a total cholesterol level >/=240 mg/dL. Carotid ultrasonography was performed to evaluate intimal-medial thickness (IMT), relative wall thickness, and the presence of plaque. Carotid pressure waveforms were recorded by applanation tonometry to measure carotid stiffness (beta) and pressure wave reflection (ie, augmentation index). After adjusting for age, body mass index, and smoking habit by analysis of covariance, no significant differences were found between normocholesterolemic hypertensives and hypercholesterolemic hypertensives in terms of IMT (0.79+/-0.19 versus 0.81+/-0.19 mm), relative wall thickness (0.27+/-0.07 versus 0.28+/-0.07), carotid stiffness (6.1+/-3.2 versus 5.6+/-2.7), augmentation index (18. 7+/-12.9% versus 17.3+/-12.8%), and prevalence of plaque (30.8% versus 30.7%). In the whole population, carotid IMT was significantly related to age (r=0.43), systolic (r=0.35) and diastolic (r=0.35) blood pressures, body surface area (r=0.22), and cholesterol levels (r=0.22) (all P<0.05). Carotid stiffness was significantly related to age, blood pressure, body mass index, and body surface area but not to cholesterol levels. In multivariate analyses, age, body surface area, and systolic blood pressure, but not cholesterol, smoking habit, or sex, were independent correlates of IMT (multiple R=0.54, P<0.0001), whereas carotid stiffness was independently associated with age, body surface area, and sex (R=0. 38, P<0.0001). In conclusion, hypertension is a potent stimulus of vascular hypertrophy. The superimposition of hypercholesterolemia does not substantially augment these changes or further increase arterial stiffness in uncomplicated hypertensive subjects.