mall, dense LDL phenotype rarely occurs as an isolated disorder. It is most frequently accompanied by hypertriglyceridemia, reduced HDL cholesterol levels, abdominal obesity, insulin resistance and by a series of other metabolic alterations predictive of an impaired endothelial function and increased susceptibility to thrombosis.
28 Evidence type: prospective
A prospective, population-based study of low density lipoprotein particle size as a risk factor for ischemic heart disease in men. Lamarche B, St-Pierre AC, Ruel IL, Cantin B, Dagenais GR, Després JP. Can J Cardiol. 2001 Aug;17(8):859-65.
Analyses were conducted in a cohort of 2057 men who were all initially free of IHD, and who were followed up over a five-year period, during which 108 first IHD events (myocardial infarction, angina or coronary death) were recorded. LDL particle size was measured by nondenaturing gradient gel electrophoresis.
RESULTS: Cox proportional hazards analysis indicated that the relationship between LDL particle size and the risk of future IHD events was not linear. Men with an LDL particle size less than 256.0 A had a significant 2.2-fold increase in the five-year rate of IHD (P<0.001) compared with men having an LDL particle size greater than 256.0 A. Multivariate and subgroup analyses indicated that small, dense LDL particles predicted the rate of IHD independent of LDL cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol, apolipoprotein B and the total cholesterol to HDL cholesterol ratio. Finally, the magnitude of the increase in IHD risk attributed to lipid risk factors was modulated to a significant extent by variations in LDL particle size.
Small, dense low-density-lipoproteins (LDL) are associated with increased risk for cardiovascular diseases and diabetes mellitus and a reduction in LDL size has been reported in patients with coronary and non-coronary forms of atherosclerosis. LDL size has been accepted as an important predictor of cardiovascular events and progression of coronary artery disease as well as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III. Small, dense LDL, with elevated triglyceride levels and low HDL-cholesterol concentrations, constitute the 'atherogenic lipoprotein phenotype (ALP)', a form of atherogenic dyslipidemia that is a feature of type 2 diabetes and the metabolic syndrome.
14 Evidence type: meta-analysis of prospective studies
Blood cholesterol and vascular mortality by age, sex, and blood pressure: a meta-analysis of individual data from 61 prospective studies with 55,000 vascular deaths. Prospective Studies Collaboration, Lewington S, Whitlock G, Clarke R, Sherliker P, Emberson J, Halsey J, Qizilbash N, Peto R, Collins R. Lancet. 2007 Dec 1;370(9602):1829-39.
Of various simple indices involving HDL cholesterol, the ratio total/HDL cholesterol was the strongest predictor of IHD mortality (40% more informative than non-HDL cholesterol and more than twice as informative as total cholesterol). Total cholesterol was weakly positively related to ischaemic and total stroke mortality in early middle age (40-59 years), but this finding could be largely or wholly accounted for by the association of cholesterol with blood pressure. Moreover, a positive relation was seen only in middle age and only in those with below-average blood pressure; at older ages (70-89 years) and, particularly, for those with systolic blood pressure over about 145 mm Hg, total cholesterol was negatively related to haemorrhagic and total stroke mortality.
15 Evidence type: post-hoc analysis
Low Levels of High Density Lipoprotein Cholesterol and Increased Risk of Cardiovascular Events in Stable Ischemic Heart Disease Patients: A Post Hoc Analysis from the COURAGE Trial. Acharjee S, Boden WE, Hartigan PM, Teo KK, Maron DJ, Sedlis SP, Kostuk W, Spertus JA, Dada M, Chaitman BR, Mancini GB, Weintraub WS. J Am Coll Cardiol. 2013 Aug 8. pii: S0735-1097(13)03082-9. doi: 10.1016/j.jacc.2013.07.051. [Epub ahead of print]
OBJECTIVES: The aim of this study was to assess