Apolipoprotein A1

Apolipoprotein A1 Blood Test measures the amount Apolipoprotein A1 in the blood. This test helps to determine the risk for heart disease.

What is Apolipoprotein A1?

Apolipoprotein A or ApoA is a protein present in the body. It helps in lipid breakdown and is a component of high-density lipoprotein (HDL, the good cholesterol). It removes the cholesterol within the blood vessels. It helps to remove all types of bad cholesterol from the body. Thus this protein helps to lower the risk of heart diseases.

Lipids cannot dissolve in blood by itself. Apolipoproteins combine with lipid to form lipoproteins and help in the transport of lipids throughout the bloodstream. Lipoproteins are spherical in structure and are of four (4) types. Each type of lipoprotein has its own characteristic protein and lipid composition. They are the high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and chylomicrons.

High-density lipoprotein (HDL) is the smallest lipoproteins. It plays an important role in the removal of excess or unused cholesterol from the cells and returns this cholesterol to the liver. The liver breaks down the returned cholesterol to bile acids and salts. These bile acids and salts are eliminated through the intestine. If there is enough HDL present in the body, it prevents the build-up of fatty plaques or deposits in the blood vessels.

Apolipoprotein A is the major protein for the high-density lipoprotein and helps in its transport. It helps the HDL to take up cholesterol from the tissues and bound by receptors in the liver where the cholesterols to be destroyed. There are two types of Apolipoprotein A, Apo A-I, and Apo A-II. Apolipoprotein A1 is present in more proportion than Apolipoprotein A-II. Assessing the levels of Apolipoprotein A1 directly reflects the high-density lipoprotein levels. Therefore low levels of Apolipoprotein A1 in the blood may increase the risk of cardiovascular diseases (heart diseases).

Why this test is performed?

This test is performed to determine whether you have normal or abnormal levels of Apolipoprotein A1 in the blood. Your doctor may ask to perform this test if you have a family history of cardiovascular diseases or if you are at risk of developing cardiovascular diseases. This test is also recommended if you have an abnormal level of high-density lipoprotein (HDL).

You may be advised to perform this test to determine the cause of your high cholesterol and to rule out whether it may be due to a disorder that is causing a deficiency in apo A-I. This test is recommended to monitor the effectiveness of treatment in individuals receiving lipid treatments.

How often this test is performed?

If you have a family history of cardiovascular diseases (heart diseases) your doctor may ask to perform this test in a 6 monthly or a yearly basis. If you are diagnosed with cardiovascular diseases (heart diseases), then you may have to perform this test on a regular basis as instructed by the doctor.

Precautions:

Certain medicines such as carbamazepine, estrogens, ethanol, lovastatin, niacin, oral contraceptives, phenobarbital, pravastatin, and simvastatin may affect the test results. Inform the healthcare provider about all the medications you take before the test.

If the test results show low levels of Apo- A1 than the normal range it may indicate the risk of cardiovascular diseases. Low levels of Apo- A1 along with high levels of Apolipoprotein B (Bad cholesterol) indicates an increased risk of cardiovascular disease.

Low levels of Apo- A1 are also seen in individuals with diabetes, chronic liver disease or chronic kidney disease. Individuals who are obese and who smoke may also show decreased levels of Apo- A1 in the blood.

High levels of Apo- A1 than the normal range may be seen in case of pregnancy. Individuals who do strenuous exercise and who take medicines such as carbamazepine, estrogens, ethanol, lovastatin, niacin, oral contraceptives, phenobarbital, pravastatin, and simvastatin may also show high levels of Apo-A1 in the blood.

Based on the test results, your doctor may advise appropriate medical treatments, lifestyle modifications, or further diagnostic tests.