Lipoprotein particle level, cholesterol content predicts atherogenic burden
MedWire News: Measuring the particle level and cholesterol content of atherogenic cholesterol and lipoproteins may be useful for cardiovascular (CV) risk prediction, US study data suggest.
Christie Ballantyne (Baylor College of Medicine, Houston, Texas) and colleagues found that measures of carotid artery plaque burden and plaque eccentricity were positively associated with total, low-density lipoprotein (LDL), and non-high-density lipoprotein (nonHDL) cholesterol, as well as apolipoprotein (apo)B and LDL particle number (LDLp).
These findings "have potentially important research implications in terms of which MRI parameters to follow when therapies that lower atherogenic lipids or raise anti-atherogenic lipids are used," remark the authors.
Using data from 1670 participants of the Atherosclerosis Risk in Communities (ARIC) study, in which carotid MRI imaging had been performed, the team investigated the relation between carotid artery plaque characteristics and various cholesterol and lipoprotein parameters.
In all individuals, vessel wall and lipid cores were measured, and the normalized wall index (NWI) and standard deviation (SD) of wall thickness were calculated (measures of plaque burden and plaque eccentricity, respectively). Lipid cores were also examined in vessels thicker than, or equal to 1.5 mm.
Ballantyne and co-authors report that, of the atherogenic lipid measures assessed, apoB, LDLp, total, LDL, and nonHDL cholesterol were all associated with maximum wall thickness and carotid wall volumes, with the strongest associations seen for total and nonHDL cholesterol. Similar results were observed for NWI.
In contrast, anti-atherogenic cholesterol (HDL cholesterol) and lipoprotein (apoA-I and HDLp) parameters were not associated with carotid wall volume, maximum wall thickness, or NWI.
Although measures of atherogenic or anti-atherogenic lipoproteins did not individually predict the presence of lipid-rich cores in the plaques of persons with arteries thicker than, or equal to 1.5 mm, ratios of atherogenic/anti-atherogenic cholesterol or particles (total/HDL cholesterol, nonHDL/HDL cholesterol, and LDLp/HDLp) were significantly associated with the presence of a lipid-rich core - one of the features of high-risk plaques.
This suggests that "lipid-rich necrotic core presence might be an important imaging parameter to follow with therapies that markedly improve the ratio of atherogenic/anti-atherogenic cholesterol (or lipoproteins)," say the researchers. The findings are published in the journal Atherosclerosis.
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By Nikki Withers