lavdensitetslipoprotein

lavdensitetslipoprotein, commonly known as low-density lipoprotein (LDL), is one of the main lipoprotein classes circulating in the blood. LDL particles are rich in cholesterol esters and have apolipoprotein B-100 on their surface. Their primary function is to deliver cholesterol to peripheral tissues, where it is used for membrane synthesis and steroid production.

LDL is produced from very-low-density lipoprotein (VLDL) after triglycerides are removed by lipoprotein lipase. Through interaction with LDL receptors on cell surfaces, LDL is taken up by receptor-mediated endocytosis, delivering cholesterol into cells. Regulation of LDL receptor activity and LDL particle numbers influences plasma LDL levels. Mutations that impair LDL receptor function or ApoB-100 can cause elevated LDL and contribute to familial hypercholesterolemia. PCSK9 and related pathways modulate receptor recycling and thus circulating LDL concentrations.

Clinically, high LDL cholesterol (LDL-C) is a major risk factor for atherosclerotic cardiovascular disease. Oxidized or otherwise modified LDL can promote foam cell formation and plaque progression. LDL-C is typically measured in blood tests; results are given in mmol/L or mg/dL. Estimates of LDL-C can be calculated from total cholesterol, HDL cholesterol, and triglycerides, but direct measurement is used when accuracy is needed. Target LDL-C levels vary by overall cardiovascular risk, with lower targets recommended for high-risk individuals.

Management of elevated LDL includes lifestyle changes—such as diet, weight management, and physical activity—and pharmacotherapy. Statins reduce hepatic cholesterol synthesis and upregulate LDL receptors; other options include ezetimibe, PCSK9 inhibitors, and newer agents that lower LDL-C through different mechanisms.