Lipoptrotein (a): Causes, Testing, and Management

Lipoprotein(a) as a cholesterol marker

Cholesterol can’t travel on its own. It relies on lipoproteins to move through the blood stream. The two main lipoprotein groups are HDL (high-density lipoprotein) and LDL (low-density lipoprotein). Most people are aware that LDL or bad cholesterol is a major cause of heart disease. However, there is a lesser-known lipoprotein group that is an important cholesterol marker: lipoprotein(a) or Lp(a).

Lipoprotein(a) particles are similar to LDL particles, but sticker than LDL, which means they are more likely to cause blockages in the arteries. High levels of lipoprotein(a) are a risk factor for heart disease and stroke.

Lipoprotein(a) isn't included in a regular cholesterol test. A routine cholesterol blood test measures LDL, HDL, tryglycerides and total cholesterol levels. It may show your LDL level is healthy. But if a large portion of the LDL-C is carried by lipoprotein(a), you have a higher risk for blockages in your arteries.

What is lipoprotein(a)

Lipoprotein(a), also known as Lp(a), is a type of lipoprotein particle that is found in the blood. It is made up of a protein called apolipoprotein(a) and a lipid molecule. Lp(a) is similar in structure to LDL cholesterol, also known as "bad" cholesterol, but it has an additional protein component.

Elevated levels of Lp(a) in the blood have been associated with an increased risk of developing cardiovascular disease, including heart attacks and strokes. Unlike other risk factors such as high blood pressure or smoking, elevated Lp(a) levels are largely genetically determined, meaning that lifestyle changes may not be effective in reducing levels.

Lp(a) Awareness Day aims to educate the public and healthcare professionals about the importance of measuring Lp(a) levels and monitoring them in individuals who are at increased risk of cardiovascular disease. By raising awareness of Lp(a) and its potential impact on cardiovascular health, the hope is to encourage more widespread testing and treatment for elevated levels.

Lifference between LDL-C and Lp(a)

Lp(a) and LDL-C (low-density lipoprotein cholesterol) are both types of lipoproteins, but they differ in their structure and function.

LDL-C is often referred to as "bad" cholesterol because it is associated with an increased risk of developing cardiovascular disease. LDL-C particles are made up of a combination of cholesterol and proteins, and their primary function is to transport cholesterol from the liver to cells throughout the body. However, when there is too much LDL-C in the blood, it can build up in the walls of arteries and contribute to the formation of plaques, which can lead to heart attacks and strokes.

Lp(a) is similar in structure to LDL-C but has an additional protein component called apolipoprotein(a). Lp(a) levels are largely genetically determined and do not respond to lifestyle changes like diet and exercise. Elevated levels of Lp(a) have been associated with an increased risk of developing cardiovascular disease, even in individuals who have normal levels of LDL-C.

While both LDL-C and Lp(a) are associated with an increased risk of developing cardiovascular disease, they have different mechanisms of action and different underlying causes. Therefore, it is important to measure both LDL-C and Lp(a) levels to fully assess an individual's cardiovascular risk.

What genetic conditions cause high Lp(a)?

Elevated Lp(a) levels are largely genetically determined and can run in families. The most common genetic condition associated with high Lp(a) levels is called familial hypercholesterolemia (FH), which is an inherited disorder that causes high levels of LDL-C in the blood. Individuals with FH may also have elevated Lp(a) levels, which further increases their risk of developing cardiovascular disease.

In addition to FH, there are other genetic conditions that have been associated with high Lp(a) levels, including:

• Apolipoprotein(a) gene variations: The apolipoprotein(a) gene is responsible for producing the protein component of Lp(a). Certain variations in this gene can lead to higher levels of Lp(a) in the blood.
• PCSK9 gene variations: The PCSK9 gene is involved in regulating LDL-C levels in the blood. Certain variations in this gene have been linked to higher levels of Lp(a).
• Lipoprotein lipase deficiency: Lipoprotein lipase is an enzyme that helps break down triglycerides, another type of fat in the blood. A deficiency in this enzyme can lead to high levels of Lp(a) and other lipoproteins.

It's important to note that not all individuals with elevated Lp(a) levels have an identifiable genetic condition. In some cases, other factors such as age, gender, and ethnicity can contribute to higher levels of Lp(a) in the blood.

How do you test for high Lp(a)?

Lp(a) levels can be measured through a blood test. The test is typically done as part of a lipid panel, which also measures other lipids in the blood such as LDL-C and HDL-C (high-density lipoprotein cholesterol). The Lp(a) test is usually ordered by a healthcare provider if an individual has a personal or family history of cardiovascular disease or if they have other risk factors for heart disease.

It's important to note that Lp(a) levels do not change significantly in response to lifestyle modifications such as diet and exercise. Therefore, the test is most useful for assessing an individual's baseline risk of developing cardiovascular disease and for monitoring the effects of medications or other interventions aimed at reducing Lp(a) levels.

The optimal level of Lp(a) in the blood is not well-defined, but higher levels are generally associated with an increased risk of developing cardiovascular disease. It's important to discuss the results of an Lp(a) test with a healthcare provider to determine what, if any, interventions are needed to manage an elevated level.

Is Lp(a) part of a normal blood test?

No, Lp(a) is not typically included as part of a standard cholesterol blood test. A standard lipid panel usually includes measurements of total cholesterol, LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglycerides. To measure Lp(a) levels, a separate blood test is required.

It's important to note that while LDL-C is commonly referred to as "bad" cholesterol, elevated Lp(a) levels are also associated with an increased risk of developing cardiovascular disease. Therefore, some healthcare providers may consider including Lp(a) testing in addition to a standard lipid panel for individuals with a personal or family history of cardiovascular disease or other risk factors.

However, Lp(a) testing is not routinely recommended for everyone, and there is currently no consensus on who should be screened for elevated Lp(a) levels. The decision to test for Lp(a) should be made on a case-by-case basis in consultation with a healthcare provide.

What should I do if I have elevated Lp(a)?

If you have elevated Lp(a) levels, it's important to work with a healthcare provider to develop a plan to manage your risk of developing cardiovascular disease. While there is no specific treatment to lower Lp(a) levels, there are several interventions that can help reduce overall cardiovascular risk.

Here are some strategies that may be recommended:

• Lifestyle modifications: Even though Lp(a) levels do not respond significantly to lifestyle changes, it's still important to maintain a healthy lifestyle. This includes following a heart-healthy diet, getting regular exercise, maintaining a healthy weight, avoiding smoking, and managing stress.
• Cholesterol-lowering medications: Medications that lower LDL cholesterol (LDL-C), such as statins, can also help lower overall cardiovascular risk, including in individuals with elevated Lp(a) levels. In some cases, other medications such as niacin or bile acid sequestrants may be used to specifically target Lp(a) levels, although the evidence supporting these treatments is not as strong.
• Regular monitoring: If you have elevated Lp(a) levels, it's important to have regular check-ups with your healthcare provider to monitor your overall cardiovascular risk and adjust your treatment plan as needed.
• Family screening: Since Lp(a) levels can be inherited, it may be recommended that family members of individuals with high Lp(a) levels undergo testing to determine their own risk.

It's important to discuss the best management plan for elevated Lp(a) levels with a healthcare provider, as treatment will depend on individual factors such as overall cardiovascular risk and any other medical conditions.

Cardiovascular disease and Lp(a)

Many individuals with elevated Lp(a) levels go on to live long, healthy lives. The most important thing is to work with a healthcare provider to develop a plan to manage your overall cardiovascular risk, which may include lifestyle modifications and/or medication.

It's also important to remember that many factors can impact cardiovascular risk, including age, gender, blood pressure, smoking status, CRP levels, and family history. Therefore, it's important to take a holistic approach to managing cardiovascular risk and address all of the factors that contribute to risk, not just Lp(a) levels.