**1. Introduction**

In recent years, the research on abnormal metabolism of blood lipids has gradually increased, and the importance of blood lipid management in primary prevention and secondary prevention of cardiovascular diseases has been clarified. This is because dyslipidemia, as a major cardiovascular risk factor, is the common pathway of multiple pathogenic factors, mainly manifested as the qualitative and quantitative changes in low-density lipoprotein (LDL), attacking the endothelium, initiating an inflammatory response, promoting the occurrence and development of atherosclerosis, and ultimately producing cardiovascular events. Thus, the understanding of the quantitative and qualitative changes in LDL is the basis of atherosclerosis treatment and prevention.
