Lipoproteins are molecules made of proteins and fat. They carry cholesterol and similar substances through the blood.
A blood test can be done to measure a specific type of lipoprotein called lipoprotein-a, or Lp(a). A high level of Lp(a) is considered a risk factor for heart disease.
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
You will be asked not to eat anything for 12 hours before the test.
Do not smoke before the test.
How the Test will Feel
A needle is inserted to draw blood. You may feel slight pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the Test is Performed
High levels of lipoproteins can increase the risk of heart disease. The test is done to check your risk of atherosclerosis, stroke, and heart attack.
It is not clear if this measurement can benefit treatment of abnormal lipid levels. Therefore, many insurance companies do not pay for it.
The American Heart Association and American College of Cardiology do not recommend the test for most adults who do not have symptoms. It may be useful for people at higher risk because of a strong family history of cardiovascular disease.
Normal values are below 30 mg/dL (milligrams per deciliter).
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The example above shows the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
Higher than normal values of Lp(a) are associated with a high risk for atherosclerosis, stroke, and heart attack.
Lp(a) measurements may provide more detail about your risk for heart disease, but the added value of this test beyond a lipid panel is unknown.
Greenland P, Alpert JS, Beller GA, et al. 2010 ACCF/AHA guideline for assessment of cardiovascular risk in asymptomatic adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2010 Dec 14;56(25):e50-103.
Genest J, Libby P. Lipoprotein disorders and cardiovascular disease. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 47.
Semenkovich, CF. Disorders of lipid metabolism. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 213.
Reviewed By: Larry A. Weinrauch MD, Assistant Professor of Medicine, Harvard Medical School, Cardiovascular Disease and Clinical Outcomes Research, Watertown, MA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.