Lipoprotein (a) - An Overview

Introduction

Lipoprotein (a), also known as Lp (a), is a protein that plays a role in transporting cholesterol within the bloodstream. Elevated levels of Lp (a) can raise the chances of the formation of plaques or blood clots in the arteries. This heightened presence of Lp (a) in the blood contributes to an increased risk of cardiovascular disease. Managing cholesterol levels through appropriate measures can help mitigate this risk.

What Is Lipoprotein (a)?

Lipoproteins serve as a category of proteins responsible for transporting cholesterol, a fatty substance, throughout the bloodstream. Two primary types of lipoproteins exist: high-density lipoprotein (HDL) cholesterol, often referred to as "good" cholesterol, and low-density lipoprotein (LDL) cholesterol, known as "bad" cholesterol. The body necessitates a specific quantity of cholesterol for optimal functioning. Cholesterol plays diverse roles within the body, including maintaining cell structure and producing steroid hormones. Elevated levels of HDL cholesterol may even assist in lowering the risk of cardiovascular disease.

Conversely, increased levels of LDL cholesterol can result in atherosclerosis, characterized by the accumulation of fatty deposits in blood vessels. This buildup raises the risk of cardiovascular disease. Lipoprotein(a) (Lp(a)) is considered a risk factor in the development of cardiovascular disease. Research indicates that Lp(a) can contribute to the formation of plaques consisting of LDL cholesterol on the walls of blood vessels. This process leads to the narrowing or blockage of blood vessels and the hardening of arteries, therefore increasing the chances of heart disease and stroke. Furthermore, apolipoprotein (a), which is a constituent of Lp (a), can impede the activity of enzymes responsible for dissolving blood clots. Consequently, it may heighten the risk of clot formation within arteries.

What Factors Cause High Lipoprotein (a)?

The primary cause of high Lp (a) levels is genetic inheritance. Lp (a) levels are largely determined by an individual's genetic makeup, specifically the LPA gene. Variations in this gene can lead to higher levels of Lp(a) in the bloodstream. As a result, individuals with a family history of high Lp(a) levels are more likely to have elevated levels themselves.

Lifestyle factors and other medical conditions typically do not significantly influence Lp(a) levels. For instance, diet, exercise, and medication interventions that may lower LDL cholesterol or triglyceride levels do not have a substantial impact on reducing Lp(a) levels.

What Are the Indications of Performing a Lipoprotein (a) Test?

If a person exhibits specific indicators or has certain health conditions that suggest an increased risk of arterial blockages, the healthcare provider may recommend conducting a test. These signs and conditions include:

• Having a family history of early heart disease or blood vessel disease (occurring before the age of 55 in a father or brother and before the age of 65 in a mother or sister).

• Elevated LDL cholesterol levels, even if a patient is taking medication to lower it.

• Previously diagnosed heart or blood vessel disease, particularly if the cholesterol and triglyceride levels are within the normal range without using cholesterol-lowering medication.

• Manifestation of inherited familial hypercholesterolemia, a genetic condition characterized by high cholesterol levels.

• History of multiple heart attacks or undergoing several procedures to open narrowed or blocked arteries in the heart (angioplasty).

• Additionally, the test may assist in determining the risks and benefits associated with taking cholesterol-lowering medications for reducing the likelihood of developing heart and blood vessel disease.

How to Perform Lipoprotein (a) Test?

A doctor will use a small needle to draw blood from a vein in the arm to obtain a blood sample for testing. Once the needle is inserted, a small amount of blood will be collected into a test tube. One may experience a slight sting as the needle is inserted or removed, but the process is generally completed in under five minutes.

What Do the Lipoprotein (a) Test Results Mean?

Elevated levels of Lp(a) can show an increased risk of cardiovascular disease, even if a person's lipid panel test results appear normal. Certain health conditions have been linked to high Lp(a) levels. These conditions include:

• Hypothyroidism: An underactive thyroid gland.

• Uncontrolled Diabetes: Poorly managed or untreated diabetes.

• Kidney Disease: Impaired kidney function.

• Nephrotic Syndrome: A kidney disorder caused by excessive protein leakage in the urine.

• In some instances, low estrogen levels may contribute to an increase in Lp(a) levels. Although rare, healthcare providers may consider testing individuals undergoing menopause to assess their cardiovascular disease risk.

What Is the Normal Range?

The American College of Cardiology guidelines acknowledge the variation in defining high Lp(a) levels. The specific thresholds for high Lp(a) can differ among individuals, considering their unique risk factors and additional health conditions. While some experts propose that high Lp(a) levels are indicated by measurements of 50 milligrams per deciliter (mg/dl) or higher, other guidelines suggest a slightly lower cutoff.

Research indicates that achieving Lp(a) levels below 50 mg/dl is desirable, as it may help mitigate the risk of cardiovascular disease. However, even levels above 25 to 30 mg/dl may still increase the likelihood of developing such conditions. For instance, studies have demonstrated that adults with Lp(a) levels exceeding 30 mg/dl face an elevated risk of heart attack and coronary heart disease. Similarly, Lp(a) levels above 50 mg/dl may heighten the risk of ischemic stroke.

Healthcare professionals generally consider low or undetectable Lp(a) levels to be indicative of good health. Normal Lp(a) levels are typically regarded as being under 30 mg/dl. Some individuals may even have undetectable levels of Lp(a).

How to Reduce the Risk of Heart Disease?

Changing one's diet and lifestyle can effectively reduce LDL cholesterol levels, lowering the risk of cardiovascular disease. The followings are steps individuals can take to improve their health and minimize their risks:

• Adopting a Heart-Healthy Diet: This involves incorporating foods rich in omega-3 oils, nuts, olive oil, select vegetable oils, whole grains, fruits, and vegetables. It is equally important to limit or avoid saturated or trans fat and processed foods.

• Engaging in Regular Exercise: Maintaining an active lifestyle can help decrease LDL cholesterol levels and increase HDL cholesterol.

• Managing Body Weight: Losing as little as three to five percent of body weight can reduce LDL cholesterol and increase HDL cholesterol. Therefore, individuals with excess weight should strive for gradual weight loss.

• Minimizing Stress: Chronic stress can contribute to elevated LDL cholesterol levels. Therefore, it is beneficial to adopt stress-reducing techniques and implement strategies for stress management.

• Quitting Smoking: Seeking assistance to quit smoking can greatly support heart health. Smoking cessation aids in reducing the risk of cardiovascular disease.

• Improving Sleep Quality: The Centers for Disease Control and Prevention (CDC) recommends aiming for seven to nine hours of sleep per night to promote the recovery and repair of the heart and blood vessels.

• Limiting Alcohol Consumption: Moderate alcohol intake can be beneficial for heart health. However, it is important to consume alcohol in moderation, and individuals struggling with alcohol dependency should seek assistance from healthcare professionals and support groups.

Conclusion

In summary, elevated levels of lipoprotein(a) (Lp(a)) indicate an increased risk of cardiovascular disease, regardless of other lipid panel test results. Genetic factors primarily cause high Lp(a) levels, with some health conditions also playing a role. While guidelines for defining high Lp(a) levels vary, research suggests that levels below 50 mg/dl are desirable. Adopting a healthy lifestyle, including dietary changes, regular exercise, weight management, stress reduction, smoking cessation, quality sleep, and moderate alcohol consumption, can help lower the risk of heart disease.