Clinical Indications

Lipoprotein cholesterol measurements are essential in managing risk for atherosclerotic cardiovascular disease (ASCVD). Atherosclerosis is defined by a buildup of plaque within arterial walls. ASCVD includes coronary heart disease, strokes, and peripheral artery disease. ASCVD develops over decades and is often asymptomatic until the patient experiences a life-threatening event such as a heart attack, stroke, or aneurysm.

Cholesterol is a lipid that is synthesized in most tissues and actively absorbed from the diet. There is a strong association between serum cholesterol concentrations and cardiovascular disease.

Cholesterol is carried in the blood by lipoproteins. Some lipoproteins carry a stronger risk of cardiovascular disease while others are associated with reduced cardiovascular risk. Total cholesterol concentration includes the sum of all "good" and "bad" cholesterol. Therefore, total cholesterol is recommended to be interpreted in context of a lipid panel that includes high-density lipoprotein cholesterol (HDL-C) and triglyceride measurements.

Low-density lipoprotein cholesterol (LDL-C) is the primary lipoprotein responsible for atherogenic plaque. Very low-density lipoprotein cholesterol (VLDL-C) is also atherogenic and the combination of LDL-C and VLDL-C is called non-HDL cholesterol and often referred to as "bad" cholesterol. Serum total cholesterol, LDL-C, and non-HDL cholesterol are all directly associated with risk for ASCVD.

HDL-C is associated with lower risk of cardiovascular disease. Excess cholesterol is actively pumped into HDL to be carried in the blood circulation and cleared by the liver in a process known as reverse cholesterol transport. For these reasons, HDL-C is often referred to as "good" cholesterol.

Triglycerides are oily lipids carried in the blood by lipoproteins. Triglycerides are primarily carried by VLDL, chylomicrons, and remnant lipoproteins. Recent evidence supports triglycerides as an independent risk factor for ASCVD. Several conditions are associated with increased plasma triglycerides, including obesity, pregnancy, physical inactivity, excess alcohol intake, kidney disease, and diabetes. Elevated triglycerides are often associated with reduced HDL-C, insulin resistance, hypertension, fatty liver disease, and increased waist circumference. In addition to cardiovascular risk, elevated triglycerides confer a risk for acute pancreatitis.