Research Biomarker Category Lipoprotein Particles and Apolipoproteins

Lipoprotein Particles and Apolipoproteins

Lipoproteins are substances made of protein and fat that carry cholesterol through your bloodstream.

Apolipoprotein A-1

Optimal range: 102 - 200 mg/dL

Apolipoprotein A is a protein carried in HDL ("good") cholesterol. It helps start the process for HDL to remove bad types of cholesterol from your body. In this way, apolipoprotein A can help to lower your risk for cardiovascular disease. Apolipoprotein A levels can be measured. But it's more common to measure the HDL and LDL ("bad") cholesterol when looking at cardiovascular risk.

This biomarker is useful for:

- Evaluating risk for atherosclerotic cardiovascular disease

- Aiding in the detection of Tangier disease

Apolipoprotein B

Optimal range: 0 - 90 mg/dL

- Apolipoprotein B (apoB) levels are used to evaluate the risk for cardiovascular disease.
- LDL and its major protein, apolipoprotein B, play an essential role in lipid transport and metabolism.
- ApoB levels are higher in males than in females and tend to increase with age.
- ApoB plays a central role in carrying cholesterol and triglycerides from the liver and gut to utilization and storage sites.
- Incontestable data support the concept that apoB is a better tool to assess cardiovascular disease than LDL-C and non-DHL-C.

Apolipoprotein B/A1 Ratio

Optimal range: 0 - 0.77 Ratio

Studies have shown that the ratio of apolipoprotein A-1:apolipoprotein B may correlate better with increased risk of coronary artery disease (CAD) than total cholesterol, and LDL:HDL ratio.

Apoprotein B100 (ApoB 100)

Optimal range: 0 - 80 mg/dL

Apolipoprotein B100 (apoB100) is a building block of very low-density lipoproteins (VLDLs), intermediate-density lipoproteins (IDLs), and low-density lipoproteins (LDLs). These related molecules all transport fats and cholesterol in the bloodstream.

HDL Large

Optimal range: 6729 - 10000 nmol/L

This test identifies 5 subclasses of HDL, 1 is identified as the large HDL subclass. Decreased levels of the large HDL subclass are associated with a 1.8-fold increased risk for CVD. Large HDL particles are functionally associated with an antioxidant, paraoxanase, which may help protect the arterial wall.

HDL-2

Optimal range: 10 - 100 mg/dL

HDL-3

Optimal range: 30 - 100 mg/dL

HDL-P

Optimal range: 30.5 - 100 umol/L

HDL-P, a measurement of total HDL particle number concentration, may be a better marker of residual risk than chemically measured high-density lipoprotein cholesterol (HDL-C, the so-called “good” cholesterol) or apolipoprotein A-1 (apoA-1, the major protein on HDL), ie, there may be a more consistent inverse association between cardiovascular endpoints and HDL-P compared with HDL-C.

Direct quantification of HDL-P concentration by NMR may be useful to refine cardiovascular risk and to evaluate novel HDL-directed therapies. Further studies are needed to clarify the role of HDL-P in clinical practice.

LDL Medium

Optimal range: 0 - 215 nmol/L

This test measures the number of particles in each of the 8 LDL subclasses. Six of these 8 subclasses are small LDL subclass particles. These smaller particles are associated with rapid uptake into the endothelium contributing to accelerated atherosclerosis.

There is a 1.3-fold increased risk for Cardiovascular diseases associated with the small LDL trait and a 1.4-fold increased risk with the medium LDL trait.

LDL Particle Number

Optimal range: 0 - 1138 nmol/L

LDL-P (LDL particle number) measures the actual number of LDL particles (particle concentration, nmol/L). It appears that LDL-P may be a stronger predictor of cardiovascular events than LDL-C.

Lipoproteins are particles that transport fats throughout the body. These particles are essential and carry a combination of proteins, vitamins, cholesterol, triglyceride, and phospholipid molecules. The composition of a lipoprotein particle changes as it circulates in the blood. Some molecules are removed and others are added, resulting in lipoprotein particles with variable amounts of cholesterol.

LDL Pattern

Optimal range: 0 - 0 Units

LDL patterns A and B refer to the size of LDL cholesterol particles in the blood. Some doctors believe that small LDL cholesterol particles in the blood may pose a greater risk for developing atherosclerosis and heart attacks than the absolute level of LDL cholesterol in the blood. The size of LDL cholesterol particles is primarily inherited. A special blood test called polyacrylamide gradient gel electrophoresis can measure particle size and determine whether a person has blood cholesterol LDL pattern A or LDL pattern B.

PATTERN A:

Persons with LDL cholesterol pattern A have large, buoyant LDL cholesterol particles. Individuals with pattern A are more likely to have normal blood levels of LDL cholesterol, HDL cholesterol, and triglycerides. Pattern A is usually not associated with an increased likelihood of atherosclerosis.

PATTERN B:

Persons with LDL cholesterol pattern B have predominantly small and dense LDL cholesterol particles. Pattern B is frequently associated with low HDL cholesterol levels, elevated triglyceride levels, and the tendency to develop high blood sugar levels and type II diabetes mellitus.

LDL Peak Size

Optimal range: 222.9 - 1000 Angstrom

An average size of LDL peak subclass particles measuring less than 218 angstroms, as measured with Ion Mobility, is associated with a 1.35-fold increased risk for CVD.

Contributing factors:

Genetics/demographics:

- Genetic predisposition

- High triglyceride and low HDL-C levels

LDL Size

Optimal range: 20.51 - 100 nm

Small LDL-P and LDL Size are associated with CVD risk, but not after LDL-P is taken into account.

LDL Small

Optimal range: 0 - 142 nmol/L

Small LDL subclass particles cause plaque buildup to progress much faster because they enter the artery wall more easily than large LDL particles. A predominance of smaller LDL particles, referred to as Pattern B lipid phenotype, represents an atherogenic lipid profile that is associated with CVD.

LDL-P

Optimal range: 0 - 1000 nmol/L

Lipoproteins are particles that transport fats throughout the body. These particles are essential and carry a combination of proteins, vitamins, cholesterol, triglyceride, and phospholipid molecules.

The composition of a lipoprotein particle changes as it circulates in the blood. Some molecules are removed and others are added, resulting in lipoprotein particles with variable amounts of cholesterol. Low-density lipoprotein particles (LDL-P) are bi-products of fat transport that remain in circulation for an extended time. While in circulation, LDL-P can penetrate the artery wall and get stuck, forming a fatty plaque. These plaques can build over time and lead to blockages, resulting in heart attacks and strokes.

LDL1 Pattern A

Optimal range: 0 - 57 mg/dL

LDL2 Pattern A

Optimal range: 0 - 30 mg/dL

LDL3 Pattern B

Optimal range: 0 - 6 mg/dL

LDL4 Pattern B

Optimal range: 0 - 0 mg/dL

Lipoprotein(a) / Lp(a)

Optimal range: 0 - 30 mg/dL

Lipoprotein(a) is a unique lipoprotein that has emerged as an independent risk factor for developing vascular disease.

LP PLA2 ACTIVITY

Optimal range: 0 - 123 nmol/min/mL

Lipoprotein-associated phospholipase A2 (Lp-PLA2), also known as platelet activating factor Acetylhydrolase, is an inflammatory enzyme that circulates bound mainly to low density lipoproteins and has been found to be localized and enriched in atherosclerotic plaques.

LP-IR Score

Optimal range: 0 - 45 Units

The LP-IR score assesses an individual’s insulin resistance level and diabetes risk.

Small LDL-P

Optimal range: 0 - 527 nmol/L

These particles are associated with an increased risk of heart disease; more of these small particles lead to greater risk. Your Small LDL particle score can vary widely, with a lower score being much better.

VLDL Cholesterol Cal

Optimal range: 2 - 36 mg/dL

What is VLDL?

VLDL stands for very-low-density lipoprotein. Your liver makes VLDL and releases it into your bloodstream. The VLDL particles mainly carry triglycerides, another type of fat, to your tissues. VLDL is similar to LDL cholesterol, but LDL mainly carries cholesterol to your tissues instead of triglycerides.

VLDL and LDL are sometimes called "bad" cholesterols because they can contribute to the buildup of plaque in your arteries. This buildup is called atherosclerosis. The plaque that builds up is a sticky substance made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, the plaque hardens and narrows your arteries. This limits the flow of oxygen-rich blood to your body. It can lead to coronary artery disease and other heart diseases.

A normal VLDL level is below 30 mg/dL. Your healthcare provider can measure your VLDL cholesterol through a simple blood test. If your VLDL is high, lifestyle changes and medication can help.

VLDL-3

Optimal range: 0 - 10 mg/dL