Echolucent Carotid Artery Plaques Are Associated With Elevated Levels of Fasting and Postprandial Triglyceride-Rich Lipoproteins

Abstract

Background and Purpose Echolucent carotid atherosclerotic plaques are associated with an increased risk of neurological symptoms. Elevated plasma triglycerides is a risk factor for cerebral and coronary infarction. This study examined these individual pathogenetic risk factors to determine whether they were related. Methods We included 85 symptomatic patients with at least 40% carotid artery stenosis. Plaque morphology of the relevant artery was evaluated by high-resolution B-mode ultrasonography as echolucent, echo-rich, or intermediate. Fasting and postprandial lipids and lipoproteins were measured before and at hourly intervals for 4 hours after a fatty meal (1 g cream fat per kilogram body weight). Results When we compared patients with echolucent plaques to patients with echo-rich or intermediate plaques, the former had higher fasting and postprandial plasma triglycerides ( P ≤.006), higher chylomicron remnants/VLDL cholesterol ( P =.02) and triglycerides ( P ≤.004), a larger area under the plasma triglyceride curve 0 to 4 hours after a fatty meal, with (AUC _{TG−TG 0h} ) or without (AUC _TG ) subtraction of fasting levels ( P =.007 and P =.003), a larger body mass index ( P =.03), and were younger ( P =.01). Multiple logistic regression analysis found that when age and body mass index were taken into account, fasting plasma and VLDL triglycerides, postprandial chylomicron remnants/VLDL triglycerides, AUC _{TG−TG 0h} and AUC _TG with odds ratios of 4.1, 3.8, 3.0, 2.7, and 4.3, respectively, were independent predictors of an echolucent plaque. Conclusions Echolucent carotid artery plaques are associated with elevated levels of triglyceride-rich lipoproteins in the fasting or postprandial state.