Lp(a): The Hidden Heart Risk Marker

The lp(a) test measures your level of lipoprotein(a), a type of cholesterol particle that is largely determined by genetics and is an independent risk factor for heart disease and stroke. Unlike LDL cholesterol, Lp(a) levels do not change much with diet or exercise, making the test a critical tool for uncovering hidden cardiovascular risk.

Key Takeaways

• Lp(a) is a genetically inherited form of cholesterol that increases the risk of heart attack, stroke, and aortic valve narrowing.
• Standard cholesterol panels do not measure Lp(a); a separate blood test is required.
• The test is recommended for people with a family history of early heart disease, unexplained high cholesterol, or a personal history of cardiovascular events.
• Results are reported in nanomoles per liter (nmol/L) or milligrams per deciliter (mg/dL), with levels above 50 mg/dL (or 125 nmol/L) generally considered high.
• No approved drugs specifically lower Lp(a) yet, but lifestyle changes and statins have little effect; emerging therapies are in clinical trials.

What is an lp(a) test?

The lp(a) test is a blood test that measures the concentration of lipoprotein(a), a variant of low density lipoprotein (LDL) cholesterol that contains an extra protein called apolipoprotein(a). This added protein makes Lp(a) particles more likely to stick to artery walls and promote blood clots. Because Lp(a) levels are about 70% to 90% determined by genetics, they remain stable throughout life and are not significantly affected by diet, exercise, or common cholesterol medications like statins. The test is usually ordered once because repeat testing rarely changes the result.

Why is high lp(a) dangerous?

High levels of Lp(a) contribute to cardiovascular disease in three main ways. First, Lp(a) particles can enter the artery wall, become oxidized, and trigger inflammation, leading to plaque formation. Second, because of its structure, Lp(a) can inhibit the breakdown of blood clots, raising the risk of thrombosis. Third, Lp(a) can deposit calcium in the aortic valve, speeding up aortic stenosis. Observational studies have shown that people with Lp(a) levels at the 90th percentile have roughly a two to three fold higher risk of heart attack and stroke compared to those with lower levels. This risk is independent of other factors such as LDL cholesterol, blood pressure, and smoking.

Who should get an lp(a) test?

Not everyone needs an lp(a) test, but several groups benefit from screening. The American Heart Association and the European Atherosclerosis Society recommend testing for people with a family history of premature coronary artery disease (heart attack before age 55 in men or 65 in women), for those with a personal history of cardiovascular events despite well controlled risk factors, and for individuals who have a family member with high Lp(a) known from a prior test. People with familial hypercholesterolemia or a history of aortic stenosis should also be tested. Some experts suggest considering testing once in all adults to better stratify cardiovascular risk.

How is the lp(a) test performed?

The lp(a) test is a simple blood draw from a vein in your arm. No special preparation such as fasting is required, though some laboratories prefer a fasting sample for consistency. The blood is sent to a lab where an immunoassay or a turbidimetric method measures the amount of Lp(a) particles. Results are typically available within one to three days. Since levels are stable, a single test is usually sufficient unless the result is borderline, in which case a repeat test may help confirm the value.

What do the results mean?

Results are reported in either milligrams per deciliter (mg/dL) or nanomoles per liter (nmol/L). In general, a level below 30 mg/dL (about 75 nmol/L) is considered low risk, between 30 and 50 mg/dL (75 125 nmol/L) is intermediate, and above 50 mg/dL (125 nmol/L) is high. However, some labs use different thresholds. It is important to understand that a high Lp(a) level does not automatically mean you will have a heart attack, but it places you at greater long term risk. Your doctor will interpret the result alongside your other risk factors such as age, LDL cholesterol, smoking, diabetes, and blood pressure. For example, someone with both high LDL and high Lp(a) may be advised to lower LDL aggressively with statins, even though statins do not lower Lp(a) itself, to offset the combined risk.

Can you lower high lp(a) levels?

Currently, no medication is approved by the Food and Drug Administration (FDA) specifically to lower Lp(a). Statins, ezetimibe, and lifestyle changes have minimal effect on Lp(a) levels. Niacin (vitamin B3) can lower Lp(a) by about 20% to 30%, but because of side effects and limited outcome data, it is rarely used for this purpose. PCSK9 inhibitors reduce Lp(a) modestly (20% to 30%) and are approved for other indications. Emerging therapies, such as antisense oligonucleotides and small interfering RNA drugs, have shown in early trials to lower Lp(a) by more than 80%, and large outcome studies are underway to confirm whether this reduction translates into fewer heart attacks and strokes. For now, if you have high Lp(a), your doctor will focus on controlling other modifiable risk factors, such as LDL cholesterol, blood pressure, and smoking. For a deeper look at how biomarkers like Lp(a) fit into the bigger picture of health tracking, see our guide on Biomarkers Explained.

Frequently Asked Questions

What is a normal lp(a) level?

There is no universal cutoff, but most guidelines consider a level below 30 mg/dL (or 75 nmol/L) as low risk for cardiovascular events. Levels between 30 and 50 mg/dL (75 125 nmol/L) represent intermediate risk, and levels above 50 mg/dL (125 nmol/L) are considered high. Some studies, however, suggest that risk begins to increase even at lower levels, especially when other risk factors are present. Your doctor can help you interpret your specific number in context.

Does insurance cover the lp(a) test?

Coverage varies. Many insurance plans, including Medicare, may cover the lp(a) test if it is ordered for a medically accepted reason, such as a personal or family history of early heart disease, unexplained high cholesterol, or known high Lp(a) in a relative. Some plans may require prior authorization. The test is relatively inexpensive, often costing between $50 and $100 out of pocket if not covered. Check with your insurer and laboratory before scheduling the test to confirm coverage and any necessary documentation.

Can diet alone lower lp(a)?

Diet has little to no effect on Lp(a) levels. Unlike LDL cholesterol, which can be reduced by a diet low in saturated fats and high in fiber, Lp(a) is primarily determined by genetics and remains stable regardless of what you eat. However, a heart healthy diet is still important because it helps lower other risk factors such as LDL cholesterol, blood pressure, and weight. While you cannot lower Lp(a) through dietary changes, overall lifestyle modification remains a cornerstone of cardiovascular prevention for everyone, regardless of Lp(a) status.

This article is for general information and is not medical advice. See our Medical Disclaimer.