"Approximately 50% of people suffering from heart attacks have shown "normal" cholesterol numbers." - National Heart, Blood, and Lung Institute (NIH), 2001
Cholesterol has historically been used as the standard indicator for cardiovascular disease, being classified as HDL (good) or LDL (bad). However, it is actually the lipoprotein particles that carry the cholesterol throughout the body--not the cholesterol within them--that are responsible for key steps in plaque production and the resulting development of cardiovascular disease.
Cardiovascular risk increases with a higher number of low density lipoprotein (LDL) particles, regardless of how much cholesterol each lipoprotein particle contains. This is because both a higher number of LDL particles or smaller sized LDL particles dramatically increase the probability of lipoproteins penetrating the arterial wall, where they can cause real damage.
Measuring the lipoprotein subgroups is the only way to evaluate emerging risk factors, which is crucial for accurate assessment of cardiovascular risk, according to the National Cholesterol Education Program (NCEP).
NCEP Emerging Risk Factors
- Small, dense LDL - these atherogenic particles easily penetrate the arterial endothelium, causing plaque
- RLP (Remnant Lipoprotein) - very atherogenic lipoprotein with similar composition and density as plaque
- Lp(a) - builds plaque and causes plaque to rupture
- HDL2b - positively correlates with heart health because it is an indicator of how well excess lipids are removed.
Over 20% of the population has cholesterol-depleted LDL. This is a condition in which a patient's cholesterol may be "normal" but their lipoprotein particle number, and hence their actual risk, is much higher than conventional cholesterol tests would indicate. This is especially common in persons whose triglycerides are high or whose HDL is low. In a cholesterol-depleted patient, there can be up to a 40% error in risk assessment!