Relation of Intima-Media Thickness to Atherosclerotic Plaques in Carotid Arteries

Abstract

This study examined the relation between arterial wall thickness and local atherosclerosis in the carotid arteries (CAs) and their specific risk factors. B-mode ultrasonography of the CAs was performed in a cohort of 516 men and 756 women aged 59 to 71 years who had been recruited for the European Vascular Aging Study. Ultrasound examination included measurement of intima-media thickness of the common CA (CCA) and the sites of plaque in the internal CA and bifurcations. Significant associations between increases in CCA intima-media thickness and both the presence and severity of atherosclerotic plaque were found in men and women. Examination of specific risk factors for increases in CCA intima-media thickness in the presence of plaque showed that, after adjustment for sex, both ultrasound measurements were independently related to age, body mass index, hypertension, and ever smoking (versus never smoking). Diabetes and current smoking were associated with intima-media thickness only, whereas hypercholesterolemia was related to plaque only. However, when subjects who were taking lipid-lowering drugs were excluded, lipoproteins and apolipoproteins were more consistently related to intima-media thickness than to plaque. In subjects free from any antihypertensive treatment, both intima-media thickness and plaques were independently associated with systolic blood pressure. After adjustment for sex and other risk factors, the odds ratio for having at least one plaque associated with a 0.10-mm increase in CCA intima-media thickness was 1.18 (95% confidence interval, 1.05 to 1.32). In this relatively aged population, increases in intima-media thickness as measured in the CCAs were clearly related to locally detected atherosclerosis and known risk factors for atherosclerosis. Longitudinal studies are needed to clarify the role of arterial wall thickening in the atherosclerotic process.