What is being tested?
Lipoprotein (a) (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).
How is it used?
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.
When is it requested?
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.
What does the result mean?
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.
Is there anything else I should know?
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.
Common questions
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.
More information
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