Apolipoprotein A
Does this test have other names?
Apo A-1, apolipoprotein a-1
What is this test?
This test measures the amount of apolipoprotein A in your blood. It helps your healthcare
provider figure out your risk for cardiovascular disease.
Apolipoprotein A is a protein carried in HDL ("good") cholesterol. It helps start
the process for HDL to remove bad types of cholesterol from your body. In this way,
apolipoprotein A can help to lower your risk for cardiovascular disease. Apolipoprotein
A levels can be measured. But it's more common to measure the HDL and LDL ("bad")
cholesterol when looking at cardiovascular risk.
Why do I need this test?
You may need this test to see if you are at increased risk for heart disease. You
may also need this test if you have already had heart problems, such as a heart attack.
This test is not used as often as a lipid profile. A lipid profile measures HDL and
LDL cholesterol. But some studies suggest that apolipoprotein A test results are a
good measure of your heart disease risk.
This test may also help your healthcare provider fine-tune your risk if you have a
family history of heart disease.
What other tests might I have along with this test?
You may also need tests that measure:
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Lipid profile
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LDL cholesterol
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HDL cholesterol
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Triglycerides
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Total cholesterol
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Apolipoprotein B
The accuracy of your heart disease risk is better when both apolipoprotein A and apolipoprotein
B levels are measured and looked at together.
What do my test results mean?
Test results may vary depending on your age, gender, health history, and other things.
Your test results may be different depending on the lab used. They may not mean you
have a problem. Ask your healthcare provider what your test results mean for you.
Results are given in milligrams per deciliter (mg/dL). For men, the normal range is
110 to 180 mg/dL; for women, the normal range is 110 to 205 mg/dL.
Your apolipoprotein A levels may be high if you:
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Have high levels of apolipoprotein (familial hyperalphalipoproteinemia)
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Have a genetic disorder called familial cholesteryl ester transfer protein deficiency
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Take medicines containing extra estrogens
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Take niacin or statins, a type of cholesterol-lowering medicine
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Take statins
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Lose weight
Your apolipoprotein A levels may be low if you have:
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Low levels of apolipoprotein (familial hypoalphalipoproteinemia)
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Tangier disease, a rare inherited disorder that lowers the amount of HDL
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Hepatocellular disorders, which are certain types of liver problems
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Poorly controlled diabetes
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Nephritic syndrome, a group of kidney problems
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Chronic kidney (renal) failure
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Coronary artery disease. This means the arteries carrying blood to the heart become
narrowed and hardened.
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Cholestasis, which means problems with the flow of bile from the liver
Smoking cigarettes, taking diuretics, or taking medicines that contain androgens can
also cause lower levels of apolipoprotein A.
How is this test done?
The test is done with a blood sample. A needle is used to draw blood from a vein in
your arm or hand.
Does this test pose any risks?
Having a blood test with a needle carries some risks. These include bleeding, infection,
bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may
feel a slight sting or pain. Afterward, the site may be sore.
What might affect my test results?
Cigarette smoking can affect this test. Certain medicines can also affect your test
results. They include:
How do I get ready for this test?
Tell your healthcare provider if you smoke or take any medicines regularly, such as
statins, diuretics, or hormone medicine. Follow your provider's directions about whether
or not you need to stop taking some of these medicines for the test. Tell your healthcare
provider about all medicines, herbs, vitamins, and supplements you are taking. This
includes medicines that don't need a prescription and any illegal drugs you may use.