Conventional Lipid Panel
The conventional lipid panel measures:
- Cholesterol: an alcohol-sterol used by the body in the production of hormones and bile acids for cell membranes.
- Triglycerides: blood fats or esters of glycol, and, like cholesterol, they are vital sources of energy for the body.
- HDL, or High-Density Lipoprotein Cholesterol: an indicator of how well the body utilizes fats.
- LDL, or Low-Density Lipoprotein Cholesterol: an indicator of a patient’s risk for atherosclerosis.
More to the Story
However, it’s the size of the lipid particles that matters. To assess for risk of heart attack or stroke, a Lipoprotein Particle Test would reveal more information.
There are five major subgroups of Low-Density Lipoproteins (LDL): Intermediate Density Lipoprotein (IDL), I, II, III, and IV. IDL is the largest, least dense, and most buoyant type, while LDL-IV is the smallest and most dense. LDL particles that are small are also dense, and these terms are often used interchangeably. The smaller the LDL particle, the more dangerous it is. In fact, small dense LDL types (LDLIII and LDL-IV) are three times more atherogenic than buoyant LDL.
According to the National Cholesterol Education Program (NCEP), only about half of the variability in coronary heart disease risk can be attributed to conventional risk factors (i.e., LDL, HDL, and triglyceride levels). Other, more specific risk factors enhance the predictive power of cardiovascular disease in individuals. High levels of small dense LDL particles are a specific risk factor that may be independent of other lipid-related risk factors. Lipoproteins transport cholesterol throughout the body, but it is the actual lipoprotein particle, not the cholesterol within them, that penetrates the arterial wall and causes heart disease. That is why it is necessary to know the number of small LDL particles.
Why Is Small-Dense LDL so Harmful?
Smaller particles of LDL can more easily penetrate the arterial wall than large LDL particles simply due to their size. Therefore, the smaller the LDL particle, the more likely it is to enter the arterial endothelium, where it becomes oxidized and is taken up by a macrophage cell, which then becomes a foam cell. This cell eventually sticks together to build plaque within the arteries. Evidence also suggests that small dense LDL participles are associated with vascular dementia.
It is also essential to know how many LDL particles are present, in addition to their size. Just as small LDL particles can fit through the arterial lining more easily than large LDL particles, the more LDL particles there are, the more likely they will enter the arterial intima, regardless of size. It is, therefore, imperative to measure both the size (density) and the number of LDL particles.
NEW CHOLESTEROL RISK FACTORS:
- Small dense LDL particles are easily oxidized and penetrate the arterial endothelium to form plaque.
- Lp(a), a small dense LDL, is involved in thrombosis.
- RLP (Remnant Lipoprotein) is very atherogenic, has a similar composition and density of plaque, is believed to be a building block of plaque, and does not need to be oxidized like other LDL particles.
- HDL2b positively correlates with heart health because it is an indicator of how well excess lipids are removed.