Cholesterol Lp(a), Lp(a)
This test measures the level of lipoprotein (a), or Lp(a), in your blood.
Lipoproteins are made of protein and fat. They carry cholesterol through your blood. Lp(a) is a type of low-density lipoprotein, or LDL ("bad") cholesterol. High levels of Lp(a) can create plaque, a buildup of cholesterol that limits blood flow through your arteries. A high level of Lp(a) can be a sign of cholesterol-related disease, such as coronary artery disease. Research has found it to be an independent risk factor for heart disease, although how that information can be used in routine medicine isn't yet well defined.
You may have this test if you have symptoms of heart disease, if you have a family history of cardiovascular disease, or if you have heart disease even though you have a normal lipid level. You can inherit abnormal levels of Lp(a).
Your doctor may order other tests to look at how well your heart is working. These tests may include:
Electrocardiogram, or ECG/EKG, to measure heart activity
Stress test to check your heart while you are exercising
Echocardiogram to show an image of your heart while it's beating
Cardiac catheterization to see if you have a clogged artery
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
Results are given in milligrams per deciliter (mg/dL). In most people, Lp(a) levels do not change much over their lifetime. Levels tend to be higher in women after menopause and tend to be slightly lower in men than women. Lp(a) levels may also vary with ethnicity. For example, African-Americans often have higher levels of the protein than whites.
In most cases, normal values for African-Americans are:
4.4 to 75 mg/dL for women
4.6 to 71.8 mg/dL for men
Normal values for whites are:
2.1 to 57.3 mg/dL for women
2.2 to 49.4 mg/dL for men
If your results are higher, it may mean you have high cholesterol and cardiovascular disease.
The test requires a blood sample, which is drawn through a needle from a vein in your arm.
Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.
Other factors aren't likely to affect your results.
You don't need to prepare for this test. But be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.