Early-Onset Carotid Atherosclerosis Is Associated With Increased Intima-Media Thickness and Elevated Serum Levels of Inflammatory Markers

Abstract

Background and Purpose— Several factors have been held responsible for the development of atherosclerosis. To avoid the masking effect of age, we evaluated correlates of carotid atherosclerosis in patients <55 years of age. Methods— Plasma lipids, oxidative resistance of low-density lipoprotein, homocysteine, inflammatory markers, plasma viscosity, and red cell deformability were measured in fasting blood samples of 100 subjects: 45 patients with >30% stenosis of the internal carotid artery, 20 patients with carotid occlusion, and 35 control subjects. Stenosis and intima-media thickness (IMT) of the carotid artery were evaluated by duplex ultrasound. Results— White blood cell (WBC) count, plasma fibrinogen, C-reactive protein (CRP), and lipoprotein(a) levels were significantly higher in patients than in control subjects, and patients had increased IMT ( P <0.01 for all comparisons). There was a tendency for higher homocysteine levels in patients. Smokers had higher WBC, fibrinogen, and CRP levels. After the effect of smoking was controlled for, WBC count, natural logarithmic transform of homocysteine, and online-measured IMT remained significantly higher in patients than in control subjects. WBC, fibrinogen, and CRP levels were highest in the highest IMT quartile ( P =0.012, P =0.007, and P =0.036, respectively). Conclusions— Inflammatory markers and homocysteine have a more important role than lipid factors in early-onset carotid atherosclerosis. We cannot recommend the measurement of low-density lipoprotein peroxidation as a routine screening test to identify high-risk patients for early-onset carotid atherosclerosis. The confounding effect of smoking on inflammatory markers should be considered in studies on atherosclerosis.