Apolipoprotein B or Apo B is a major protein that forms the main component of low density lipoprotein complexes or LDL cholesterol. Apo B transports this LDL cholesterol, which is bad cholesterol and triglycerides to tissues and cells. High levels of apo B indicate increased risk from heart disease. Many of the body's cell receptors recognize apo B and promote the absorption of cholesterol into cells. This continued absorption finally leads to the formation of plaque that can cause vascular disease leading to heart disease. Although research shows some evidence of a genetic component, what you eat can also significantly increase the risk of heart disease caused by apo B build up. There are two main types of apolipoprotein B, they are apolipoprotein b100 and apolipoprotein b48.
Low-density lipoprotein (LDL) cholesterol is responsible for plaque formation, while High-density lipoprotein (HDL) cholesterol is responsible for removing plaque-forming substances. If a doctor suspects that a patient is at a high risk of heart disease, then he or she may ask for the patient to undergo the apolipoprotein b test. The test may also be prescribed to help in diagnosing a rare form of apo B deficiency, or if the patient has a family history of heart disease.
For the apolipoprotein b test, a blood sample is collected from your forearm. The healthcare provider will tie a band around your arm. This will cause the vein below the band to swell with blood. He or she will then cleanse the skin on your arm with an anti-septic lotion. Then, using a sterilized needle that is attached to a vial or a tube, the healthcare provider will puncture the vein and draw out a blood sample. After collecting the sample, the needle is removed, and a small bandage is placed on the puncture site. The blood sample will be sent to the lab to check for apolipoprotein b100. This test normally does not measure apolipoprotein b48.
Except for a 12 hour fast before the test, no special preparation is required for the apolipoprotein b test. However, you should note that your doctor may ask you to undergo a few other related tests such as the LDL-C, HDL-C, and test for triglycerides along with the apolipoprotein b test. Make sure you mention all your medication to the doctor before undergoing the test, as these may interfere with the test results.