Lipoprotein little a
To give your doctor additional information about your risk of having a heart attack (coronary artery disease [CAD]) or stroke (cerebrovascular disease [CVD]) due to hardening of the arteries (atherosclerosis).
When you have a family history of high Lp(a) levels and/or there is a tendency for people in your family to have heart attacks at a relatively young age; when you have heart disease but your lipid profile is not very abnormal.
A blood sample drawn from a vein in your arm
No test preparation is needed; however, since this test may be performed at the same time as a complete lipid profile, fasting for at least 12 hours may be required.
Lp(a) is a type of so-called `bad’ lipoprotein. Lipoproteins are tiny particles that carry cholesterol in the bloodstream. High levels of `bad’ lipoproteins may lead to hardening of the arteries, and eventually, to heart attack, strokes and other vascular diseases.
A tendency to high Lp(a) levels runs in families. That is, a person’s Lp(a) level is due more to their genes than to factors like diet. People with severe kidney failure may also have high levels of Lp(a).
A blood sample is obtained by inserting a needle into a vein in the arm.
Lp(a) is not currently included in the routine ‘lipid profile’. However your doctor may request it to help judge your risk of heart attack if you have a strong family history of heart attack at a relatively young age.
Some doctors may also order these tests on patients who already have heart disease or other vascular diseases, especially if the results of routine tests are not very abnormal. Many people who have heart attacks have normal cholesterol levels, so doctors are starting to look at other factors that may have an influence on heart disease, such as high Lp(a) levels.
Lp(a) may be requested when a doctor is trying to assess a person’s risk of having a heart attack or the doctor has reason to suspect an unusual cause of heart disease, particularly if the condition seems to run in the family.
A high Lp(a) level may increase a person's risk for developing heart attacks (coronary artery disease) and other vascular diseases such as strokes (cerebrovascular disease).
A tendency to a high Lp(a) level may run in the family. That is, a person’s Lp(a) level is determined by genes much more than by factors like diet. In some families, a high Lp(a) level may be associated with the inherited disorder familial hypercholesterolaemia.
The Lp(a) level tends to remain relatively constant over a person’s lifetime. It does not change with changes in diet nor with most drugs used to treat high cholesterol.
People may also develop a high level of Lp(a) with:
Having a low level of Lp(a) does not appear to cause problems.
In general, lipids should not be measured during a fever or major infection, within four weeks of an acute myocardial infarction (heart attack), a stroke or major surgery, right after excessive alcohol intake, with severely uncontrolled diabetes, during pregnancy or rapid weight loss.
Lp(a) does not usually respond to medications or lifestyle changes but if you have a high Lp(a) level you may be advised to try harder to reduce your LDL-cholesterol level.
Typically, Lp(a) levels are only tested once because they are usually fairly constant. Occasionally, your doctor may order a second Lp(a) to confirm the initial level or to see if your risk has increased significantly after menopause or to monitor the effects of treatment.
The term `apolipoprotein (a)’ means more or less the same as Lp(a). Apolipoprotein (a) is part of the Lp(a) molecule.
There is another lipid test known as apolipoprotein A-1 (Apo A). This is a different test that is related to HDL cholesterol.
Lipid profile, Apo A, Apo B, homocysteine, hs-CRP
Conditions: Heart attack, stroke, congestive heart failure, angina pectoris
RCPA Manual: Apolipoprotein
Last Review Date: September 4, 2017