Atherogenic lipoproteins particle size and number are more critical determinant of cardiovascular risk than mass of cholesterol present within these – An overview

Sir,Dyslipidemia is one of the important risk factors for cardiovascular (CV) diseases. As per the current consensus, we assess lipid-derived risk by looking at traditional lipid parameters. We consider low-density lipoprotein cholesterol (LDLc) as a primary therapeutic target. However, many recent studies have claimed apolipoprotein B and non-high-density lipoprotein cholesterol (HDLc) are more accurate in this regard. In India, raised triglyceride levels are a unique and important feature of dyslipidemia. In the presence of high triglycerides, LDLc gets oxidized and becomes a small dense form that is considered more atherogenic than large buyont LDL particles. Hence, in this subset of patients, LDL particle number and size would be more accurate measures of lipid parameters. To explore this aspect, we wrote this short communication to you. Lipoproteins (Lps) are the major contributor to atheromatous plaque formation. Among atherogenic Lps, LDLc has long been considered a major Lp and thus it became a major therapeutic target in all lipid-lowering therapies. Atherosclerotic CV disease (ASCVD) risk is linearly associated with LDLc level. It has been demonstrated that each mmoL/lit decrease in LDLc level is associated with a 20–25% reduction in the risk of major ASCVD events. We have been assessing lipid-derived ASCVD risk by looking at traditional lipid parameters for the last few decades. However, traditional lipid parameters do not reflect the entire atherogenic Lps in the plasma such as Lp(a), and apolipoprotein-B. It has been found in several recent studies that a subset of patients, even with optimal LDLc levels they continue to get ASCVD events and atherosclerosis process progression. This phenomenon has been termed as “residual lipid risk” which cannot be identified by measuring LDLc level alone. Residual lipid risk is the difference between the estimated LDLc value and the actual quantity of circulating atherogenic Lp particles. Non-HDLc comprises cholesterol carried by all potential atherogenesis Lps including LDLc, VLDL, Lp(a), and remnant Lps. Apolipoprotien-B represents the total number of atherogenic Lps in the plasma as each Lp particle contains one molecule of apolipoprotein-B. LDLc represents the total cholesterol concentration of LDL, IDL, and Lp(a). However, LDLc level does not reflect the LDL particle number and size.6 For example, at the same level of LDLc people with small-sized LDL particles will have more number of LDLc particles tha