So far in discussing advanced heart testing, I’ve covered imaging (carotid ultrasound (cIMT) and coronary calcium scoring). I’ve also written about “biomarkers” of disease which include genetic tests and markers of inflammation.
It’s time to consider advanced lipid testing. We are now able to go beyond basic lipid testing which measured total cholesterol, LDL (“bad chol.”), HDL (“good” chol.), and triglycerides. The new tests measure the number of lipoprotein particles which carry cholesterol rather than cholesterol itself. Since cholesterol is not soluble in the blood, it must be transported around by protein/lipid carriers. These are called lipoproteins. Picture a submarine which carries cholesterol through the bloodstream to it’s intended destination. It turns out that heart disease risk correlates with the number of certain lipoprotein particles more closely than with the amount of cholesterol. We also find that the size of LDL particles is very pertinent. All of this can be measured precisely now. We are using this information to guide initial choice of treatment and to follow the success of treatment. Particle number, of course, is considered in conjunction with other tests previously mentioned. LDL particles, for example, are more prone to enter vessel walls and create plaques if they are oxidized or if the vessel wall is inflamed. In the next post, I will discuss LDL particles and their connection to disease risk.