Plasma apolipoprotein(b) to LDL cholesterol ratio as a marker of small, dense LDL.

Abstract

A predominance of small, dense LDL in plasma is predictive of coronary risk' and a hallmark feature of an atherogenic lipoprotein phenotype (ALP).2 The measurement of small, dense LDL (LDL pattern 'B') has traditionally been based on the separation of LDL subclasses by density gradient ultra-centrifugation and gradient gel electrophoresis. However, these techniques are expensive, time consuming and unsuitable for routine applications and the screening of large cohorts. While more rapid procedures are currently under development, it is possible to gain information on the nature of LDL subclasses by measuring the ratio of plasma apolipoprotein(b) [apo(b)] to LDL cholesterol (LDL-C),3 since this will increase as LDL particles become small and dense. The aim of this study was to examine the strength of the relationship between the concentration of small, dense LDL as measured by density gradient centrifugation and the ratio of plasma apo(b) to LDL-C, with a view to this ratio acting as a surrogate marker for small, dense LDL.