ENDOTHELIAL FUNCTION AND COMMON CAROTID-ARTERY WALL THICKENING IN PATIENTS WITH ESSENTIAL-HYPERTENSION

Intimal-medial thickening of the carotid wall is considered an early m arker of atherosclerosis. Endothelial function is impaired in the pres ence of various cardiovascular risk factors that are implicated in the pathogenesis of atherosclerosis. To evaluate the relationship between vascular reactivity and carotid intimal-medial thickening, in 44 (mea n+/-SD age, 45.7+/-8.8 years; range, 28 to 60 years; 31 men and 13 wom en) patients with essential hypertension who had never been treated an d whose history of increased blood pressure was no longer than 12 mont hs, we evaluated several parameters: intimal-medial thickening of the common carotid arteries (by B-mode ultrasound); forearm vascular respo nse (by strain-gauge plethysmography) to intrabrachial infusion of ace tylcholine (0.15, 0.45, 1.5, 4.5, and 15 mu g/100 mL forearm tissue pe r minute), an endothelium-dependent vasodilator, or sodium nitroprussi de (1, 2, and 4 mu g/100 mL forearm tissue per minute), an endothelium -independent vasodilator; calculated minimal forearm vascular resistan ces (the ratio between mean arterial pressure and maximal forearm vaso dilation induced by 13 minutes of ischemia and 1 minute of exercise); and left ventricular mass index ton echocardiography profile). Carotid wall intimal-medial thickening showed a significant (P<0.001) inverse correlation with vasodilation to acetylcholine (r=-0.58) and age (r=- 0.40), whereas no correlation was observed with the response to sodium nitroprusside or with minimal forearm vascular resistances, left vent ricular mass index, systolic and diastolic blood pressures, and plasma cholesterol ansi glucose levels. Moreover, vasodilation to acetylchol ine showed no correlation with minimal forearm vascular resistances or left ventricular mass index. Although comparison of different vascula r ''districts,'' such as the forearm microcirculation and carotid arte ry, does not allow for a conclusive interpretation, the present data i ndicate that in patients with essential hypertension, carotid wall thi ckening is associated with reduced endothelium-dependent vasodilation and suggest that endothelial dysfunction might be involved in early ar terial structural alterations.