A high concentration of
low-density lipoprotein cholesterol (
LDL-C) in plasma is one of the strongest risk factors for atherosclerotic
cardiovascular disease and mortality. The most common approach to determining
LDL-C in the clinical laboratory is the Friedewald calculation. There is an increased interest to improve the accuracy of
LDL-C estimated by this equation. The expert panel convened by National
Cholesterol Education Program has recommended the development of accurate direct methods to measure
LDL-C. Several homogeneous and fully automated methods have been introduced in recent years that show improved precision and accuracy over earlier methods, especially the Friedewald calculation. Each of the atherogenic particles in plasma--very-low, intermediate-, and
low- density lipoprotein--as well as
lipoprotein (a), contain one molecule of
apolipoprotein B (
apoB) and thus, plasma total concentration of
apoB reflects the number of atherogenic particles. Several studies suggested that the measurement of
apoB could improve the prediction of risk of
coronary artery disease. Thus, in addition to the newly developed direct assays, alternative calculation procedures have been proposed that also take into consideration total serum
apoB concentration for the estimation of
LDL-C and the presence of small, dense
LDL particles. The new generation of homogenous methods for the measurement of
LDL-C and the use of serum
apoB concentration for the estimation of
LDL-C can contribute to the accurate
LDL-C determination.