Beyond LDL cholesterol in assessing cardiovascular risk: apo B or LDL-P?

Because the LDL-C measurement is a measure of the amount of cholesterol being carried in LDL, it is not a reliable measure of LDL particle concentration: small, dense LDL particles have much less cholesterol than large, buoyant LDL particles. Several methods have emerged that allow a more direct quantification of the number of LDL particles. Because an LDL particle contains a single molecule of apo B, it is possible to directly estimate the number of particles through a simple measurement of apo ? concentration (particularly when expressed in molar units), apo ? is typically measured by immunonephelometry or immunoturbidimetry, and reagents are available from a wide variety of manufacturers.