A new marker for heart disease risk?

Heart disease remains one of the leading causes of illness and death worldwide. While common risk factors such as high cholesterol, high blood pressure, smoking, and diabetes, science has identified another important marker called lipoprotein(a) that may increase the risk of cardiovascular disease…

The following article explains what lipoprotein(a) is, why it matters, and when testing may be recommended.

What are Lipoproteins?

While many of us maybe familiar with the term cholesterol and how having high cholesterol can increase our risk of heart disease. Cholesterol is a fat-like substance (also known as a lipid) that the body needs to build cells, produce hormones, and support other important functions.

However, cholesterol cannot travel around the body on its own. This is because blood is mostly water, and fats do not mix well with water.

To move cholesterol around the body, it needs help from special particles called lipoproteins. Lipoproteins act like transport vehicles in the bloodstream, carrying cholesterol and other fats to different parts of the body where they are needed.

Lipoproteins are made from a mixture of fat and protein. This structure allows them to carry fats through the watery environment of the blood.

The protein part of a lipoprotein is called an apolipoprotein. Apolipoproteins help hold the particle together and guide where the cholesterol goes in the body. There are six main types of apolipoproteins: A, B, C, D, E and H. Two of the most important are Apolipoprotein A1 (ApoA1) and Apolipoprotein B (ApoB)

We’ve done a separate article on apolipoprotein A1 and apolipoprotein B

There are five main types of lipoproteins, and you may be familiar with two of the most commonly talked about:

• High-density Lipoprotein (HDL) – often referred to as the “good cholesterol” as it carries cholesterol back to your liver to be removed out of your body. High levels of HDL reduce your risk of cardiovascular (heart) disease.
• Low-density lipoprotein (LDL) – often referred to as the “bad cholesterol” as it causes accumulation of plaque inside blood vessels which can cause them to narrow, called atherosclerosis, increasing your risk of cardiovascular (heart) disease.

Other lipoproteins include Very low-density lipoproteins (VLDL), Intermediate-density lipoproteins (IDL) and Chylomicrons.

What Is Lipoprotein(a)?

Lipoprotein(a) is a type of LDL cholesterol. It is made by the liver and is formed when an LDL-particle combines with additional proteins Apolipoprotein B and Apolipoprotein A. This combination makes it more “sticky,” allowing it to attach more easily to blood vessel walls, increasing the risk of cardiovascular problems. High levels of Lipoprotein(a) are a risk factor for atherosclerosis, and over time, these changes can increase the risk of cardiovascular or heart disease such as a heart attack or stroke.

Why having a high Lipoprotein(a) can be a problem

Large population studies have shown that high levels of lipoprotein(a) are strongly linked to an increased risk of heart disease. This risk is considered independent of other common risk factors, meaning it can raise your cardiovascular risk even when your cholesterol levels, blood pressure, diabetes and other conditions are taken into account. It is thought lipoprotein(a) increases heart disease risk through two main mechanisms:

• Increasing plaque build up (atherosclerosis) by increasing the growth of these plaques which can potentially cause inflammation in artery walls. Because lipoprotein(a) has a “sticky” protein component called apolipoprotein(a), it can attach more easily to the lining of blood vessels and remain there longer than LDL cholesterol, which may worsen artery damage over time.
• Increasing the risk of heart attacks by promoting blood clot formation. The apolipoprotein(a) component of lipoprotein(a) is similar to proteins involved in the body’s clotting system, which may interfere with the normal breakdown of clots. This can encourage clots to form and persist on the inner lining of blood vessels, increasing the risk of artery blockage.

Some researchers believe that lipoprotein(a) may increase heart disease risk more through its effects on blood clotting than through causing plaque build-up in the arteries.

Can I influence my lipoprotein(a) level?

The amount of lipoprotein(a) in your blood is largely down to genetics, meaning they are mainly determined by your genes rather than lifestyle factors.

This means:

• Diet and exercise usually do not significantly lower Lipoprotein(a)
• Levels tend to stay fairly constant throughout life
• High levels often run in families

It is thought that up to 20% of the population may have an increased level of lipoprotein (a).

Lipoprotein(a) levels are generally similar in both men and women, but they can vary between different populations. Studies have found lower levels in some groups, such as Chinese and Japanese populations, and higher levels in others, including people of African ancestry. While clear treatment targets exist for LDL cholesterol based on strong clinical trial evidence, the evidence for specific lipoprotein(a) thresholds is less definitive. However, people with lipoprotein(a) levels in the highest 10% of the population appear to have a significantly increased risk of cardiovascular disease.

Getting a blood test for lipoprotein(a)

A high lipoprotein(a) usually does not cause symptoms, so you usually only discover you have elevated levels after a blood test. Some researchers suggest all adults should have their lipoprotein (a) measured at least once to identify any hidden genetic risk.

Testing your levels of lipoprotein (a) is not routinely undertaken, but may be recommended if you:

• Have a family history of early heart disease or stroke
• Have unexplained cardiovascular disease
• Have a family history of high cholesterol (familial hypercholesterolaemia)
• Have high cholesterol that does not respond to treatment

You can order our Lipoprotein (a) blood test or Advanced Cholesterol Blood Test which includes a full cholesterol/lipid profile togehter with testing for Lipoprotein (a), Apolipoprotein A1 and B.

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Key Takeaways

• Lipoprotein(a) (Lp(a)) is a cholesterol-carrying particle in the blood.
• High levels are largely genetic and cannot usually be changed by lifestyle alone.
• Elevated Lp(a) significantly increases the risk of heart disease and stroke.
• Many people are unaware of their levels because it is not always included in routine cholesterol tests.
• A simple blood test can identify Lp(a) levels and help guide cardiovascular risk management.