Low-density lipoproteins (LDLs) exist as discrete subfractions that vary in size and density. A predominance of small, dense LDLs is seen in patients with ischaemic heart disease and non-insulin-dependent diabetes, and is more common in men than in women. Because small, dense LDLs are associated with increased levels of triglyceride and low levels of high-density-lipoprotein cholesterol, their exact role as an independent cardiovascular risk factor is unknown. These lipoproteins exhibit abnormal characteristics, however, such as increased susceptibility to oxidation and decreased LDL receptor binding, which may result in increased atherogenicity.
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SuperkoHRKraussRM: Differential effects of nicotinic acid in subjects with different LDL subclass patterns. Atherosclerosis1992, 95:69–76. The authors suggest that individuals with small, dense LDLs have a greater lipid reduction with nicotinic acid than those with large LDLs.
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29.
ChaitABrazgRLTribbleDL: Susceptibility of small, dense, low-density lipoproteins to oxidative modification in subjects with the atherogenic lipoprotein phenotype, pattern B. Am J Med1993, 94:350–356. In this study, LDLs were associated by DGU and six separate fractions were subjected to in-vitro oxidation. The denser LDLs were found to be more susceptible to oxidation than the larger buoyant LDLs from the same individual. This paper also contains data suggesting that subjects with the pattern-B (small dense) LDL phenotype have LDL that is more easilly oxidized than that of subjects with the pattern-A phenotype.
30.
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de GraafJHendriksJCMSwinkelsDWDemackerPNMStalenhoefAFH: Differences in LDL receptor-mediated metabolism of three low density lipoprotein subtractions by human monocyte-derived macrophages: Impact on the risk for atherosclerosis. Artery1993, 20:201–230. These elegant cell-culture studies showed that small, dense LDL is taken up less avidly by the normal LDL receptor pathway than is large LDL.
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36.
DyceMCAndersonTJYeungACGanzPLiebermanEHGerhardMD: Indices of LDL particle size closely relate to endothelial dysfunction [abstract]. Circulation1993, 88 (suppl 1):466. This abstract is the first report suggesting that small, dense LDLs may be responsible for endothelial dysfunction.
