Lipoprotein (a)

Lipoprotein(a), commonly written as Lp(a), is a genetically inherited form of LDL cholesterol that plays a distinct role in cardiovascular disease risk. Elevated Lp(a) levels are linked to a higher likelihood of developing conditions such as atherosclerosis, heart attack, stroke, and narrowing of the aortic valve. Unlike other cholesterol markers, Lp(a) levels are driven mainly by genetics rather than lifestyle factors like diet or physical activity.

Lp(a) consists of a standard LDL particle combined with a protein called apolipoprotein(a), or apo(a). This combination creates a particle that tends to adhere to blood vessel walls, encouraging plaque formation, inflammation, and abnormal clotting. A simple blood test can measure Lp(a), and clinicians often request it when someone has early-onset heart disease or a strong family history of cardiovascular problems.

What Lp(a) Is and How It Works

• Structure: Lp(a) is a large cholesterol particle formed when an LDL-like particle binds to apolipoprotein(a), a distinctive protein that gives Lp(a) its unique properties.

• Sticky and Pro-Clotting: Apo(a) closely resembles plasminogen, a molecule involved in breaking down blood clots. However, apo(a) does not perform this function and may instead interfere with normal clot removal, increasing the tendency for clot formation.

• Inflammatory Effects: Lp(a) carries oxidized phospholipids that promote inflammation, contributing to plaque buildup in arteries and calcium accumulation in the aortic valve.

Why Lp(a) Matters

• Significant Risk Factor: High Lp(a) levels are associated with increased risk of coronary artery disease, heart attacks, strokes, and calcification of the aortic valve.

• Mostly Genetic: Because Lp(a) levels are inherited, lifestyle changes typically have minimal impact on lowering them.

• Often Overlooked: Individuals may have healthy habits and normal cholesterol levels yet still face elevated cardiovascular risk due to high Lp(a).

When Testing May Be Helpful

• A personal or family history of heart disease or stroke at a young age.

• A diagnosis of familial hypercholesterolemia (FH).

• Situations where LDL cholesterol levels alone do not fully explain cardiovascular risk.