Apolipoprotein Profile Blood Test measures the levels of different types of Apolipoproteins such as Apo A1, B, C and E in the blood. This test helps to determine 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.
Apolipoprotein A or ApoA is a component of high-density lipoprotein (HDL, the good cholesterol). It removes the bad cholesterol within the blood vessels and from the body. 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 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. Therefore low levels of Apolipoprotein A1 in the blood may increase the risk of cardiovascular diseases (heart diseases).
Apolipoprotein B or Apo B is the main protein component of low-density lipoprotein (LDL, the bad cholesterol) and very low-density lipoprotein (VLDL). Chylomicrons are lipoproteins that carry dietary lipids to the liver. In the liver, these dietary lipids combine with Apo B to form triglyceride-rich VLDL. This combination is then transported across the bloodstream releasing lipids.
Lipoprotein lipase is an enzyme that helps to remove triglycerides from VLDL. As VLDL gets free off of triglycerides, it becomes intermediate-density lipoprotein (IDL) first and then LDL. The more cholesterol-rich LDL that are formed are transported across the body. Apolipoprotein B is the major protein for the low-density lipoprotein and helps in its transport. It helps the LDL to bind with receptors in the cells and promote the uptake of cholesterol into the cells. If there are high levels of LDL in the body, it results in the build-up of fatty plaques or deposits in the blood vessels. Therefore high levels of Apolipoprotein B in the blood may increase the risk of cardiovascular diseases (heart diseases).
Apolipoprotein C or Apo C is the main protein component of chylomicrons, low-density lipoprotein (LDL, the bad cholesterol), very low-density lipoprotein (VLDL) and high-density lipoprotein (HDL, the good cholesterol). Apolipoprotein C is consists of four apolipoproteins namely C1, C2, C3, and C4. These proteins help in the breakdown of triglycerides rich lipoproteins (TG-rich lipoproteins) by activating lipoprotein lipase. Lipoprotein lipase is an enzyme that helps to remove triglycerides from the lipoproteins. Apolipoprotein C activates lipoprotein lipase enzyme and helps to remove the triglycerides from the lipoproteins. Increased levels of triglycerides rich lipoproteins may cause cardiovascular diseases (heart diseases).
Apolipoprotein E is a fat-binding protein present in the body. It is the main protein component of chylomicrons, and intermediate-density lipoprotein (IDL). Apo E is mainly produced by the liver and helps in cholesterol breakdown. It is also produced by astrocytes (nerve cells) and known as the primary cholesterol carrier in the brain. Apolipoprotein E helps in the lipoprotein breakdown (Lipoprotein Metabolism). Inadequate levels of Apo E may increase the levels of cholesterol and triglycerides in the blood. This may lead to the risk of developing heart diseases.
Assessing the levels of different types of Apolipoproteins such as Apo A1, B, C and E in the blood reflects the risk of cardiovascular diseases (heart diseases)
This test is performed to determine whether you have normal or abnormal levels of Apolipoproteins 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.
You may be advised to perform this test to diagnose the cause of abnormal lipid levels, especially when someone has elevated triglyceride levels. This test is recommended to monitor the effectiveness of treatment in individuals receiving lipid treatments.
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.
Certain medicines such as androgens, beta blockers, diuretics, progestins, estrogen, 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.
Inform your doctor if you are on any medications, have any allergies or underlying medical conditions before your Apolipoprotein Profile. Your doctor will give specific instructions depending on your condition on how to prepare for Apolipoprotein Profile.
You may ask to fast (without eating anything) for a whole night or for up to 9 to 12 hours. Usually, the blood is drawn in the morning after an overnight fasting. However, follow all the instructions given by your healthcare provider.
If the test results show low levels of Apolipoprotein- A1, C, E and high levels of Apolipoprotein B than the normal range it may indicate an increased risk of cardiovascular diseases.
Based on the test results, your doctor may advise appropriate medical treatments, lifestyle modifications, or further diagnostic tests.
|MALE||All age groups||> 120 mg/dl|
|FEMALE||All age groups||> 140 mg/dl|
|UNISEX||All age groups||< 130 mg/dl|