LDLcholesterol

LDL cholesterol, or low-density lipoprotein cholesterol (LDL-C), is a type of lipoprotein that transports cholesterol in the bloodstream. LDL particles deliver cholesterol to cells throughout the body and are produced mainly by the liver. Each particle contains apolipoprotein B-100 and cholesteryl esters, and LDL uptake into cells occurs via LDL receptors. Because excess LDL-C can accumulate in arteries, high levels are associated with atherosclerotic cardiovascular disease.

LDL-C is typically measured in blood tests. In many laboratories it is reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). LDL-C is often calculated from total cholesterol, HDL cholesterol, and triglycerides using the Friedewald equation when triglycerides are not very high; direct measurement is also available. Desirable levels vary by guideline and risk, but many references consider LDL-C below 100 mg/dL (<2.6 mmol/L) as optimal for adults without established disease; levels 130–159 mg/dL are considered borderline high, 160–189 high, and 190 mg/dL or higher very high.

Elevated LDL-C contributes to plaque formation in arteries, promoting narrowing and hardening that can lead to heart attack or stroke. Risk is influenced by age, blood pressure, smoking, diabetes, and family history, and some people have elevated LDL-C despite normal overall risk.

Management focuses on lowering LDL-C. Lifestyle changes include a heart-healthy diet low in saturated fat, regular physical activity, weight control, and smoking cessation. When LDL-C remains above target or risk is high, medications are used, most commonly statins; other options include ezetimibe, PCSK9 inhibitors, bile acid sequestrants, and bempedoic acid. Inherited forms such as familial hypercholesterolemia require early, sometimes aggressive, treatment.