Triglycerides Information and Courses from MediaLab, Inc.

We are all aware of the clinical laboratory's role in assessing overall health and we are also aware that measuring a patient's serum lipids will provide some insight into their cardiovascular health. The traditional measurements of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides are the 'classic' cardiovascular risk markers.Laboratorians, and even the general public are now well-aware that LDL-C ('bad' cholesterol) concentrations should be low while HDL-C ('good' cholesterol) concentrations should be high. Triglycerides should be kept in check as well. Optimal levels are shown in the table below. So what is the risk if these values are not within optimal ranges?Cardiovascular risk can be simply defined as increasing the odds of having a pathology which affects blood flow and/or the heart. The most common cardiovascular pathology is atherosclerosis. Other cardiovascular pathologies whose odds increase as serum lipids and other cardiovascular markers become suboptimal are myocardial infarction (heart attack), stroke, congestive heart disease and coronary artery disease. Other diseases such as diabetes and the metabolic syndrome are also strongly associated with the classic cardiovascular risk markers LDL-C, HDL-C and triglycerides.

Many lipophilic substances, including fat-soluble vitamins, cholesterol, and triglycerides are essential for life. The body needs to be able to absorb and transport these substances. However, lipophilic substances are not water-soluble, and, since blood is aqueous, this presents a challenge. The body addresses this need by using 'carriers' which can bind or sequester lipophilic molecules to aqueous 'vehicles' and thus transport them through the aqueous environment of the blood. Small lipid-soluble hormone molecules like estrogen, testosterone or cortisone are carried through the blood by binding to carrier proteins. Cholesterol and triglycerides are carried through the body in small spherical particles which trap the lipophilic molecules in their centers. These particles have an outer shell that is polar on the surface so that the particles are soluble in the blood but they have a lipophilic core which can hold fat-soluble molecules.

Recall that the inflammatory events leading to atherosclerosis are due to the presence of LDL particles which diffuse through the endothelium and into the vessel wall. It makes sense that the more LDL particles there are, the more risk there would be for LDL depositing in the vessel wall. It would seem therefore that measuring the number of LDL particles could be more useful than measuring the cholesterol content of the particles. Traditional measurements of LDL-C quantify the amount of cholesterol associated with all the LDL in a patient sample; they don't tell us how many LDL particles there are. An analogy can be made with battleships. If you wanted to measure the size of a navy that was sailing for your shores, it makes more sense to count the number of ships than to count the amount of cargo the ships carry in order to estimate the number of ships. Of course, it is intuitive that the more LDL-C there is, the greater the number of LDL particles. In that sense, LDL particle number should correlate to LDL cholesterol, and this is indeed true. However, studies now show that measurement of the number of LDL particles is a more powerful predictor of cardiovascular risk. The exact relationship between LDL particle number and cholesterol content actually varies due to the fact that the lipoproteins vary in size and in the ratio of triglycerides to cholesterol. So, although cholesterol is related to LDL particle number, it is not in perfect proportion.How can we then measure LDL particle number? The most obvious way would be to measure apolipoprotein B100 (often abbreviated ApoB). Each LDL particle has one molecule of ApoB attached to it. Therefore, if we measured ApoB, we would be measuring the number of LDL particles, not the contents of those particles, and number appears to be more important with regard to adverse outcomes.

Lipids are fats dispersed in plasma. They include: Triglycerides Cholesterol Lipoproteins The amount and ratios of various lipids in the blood will determine a person’s risk of getting coronary artery disease.