Contributed by Healthians Team
What is Apoa1 test?
Apolipoprotein A-I (Apo-A1) is a functional protein that comprises 70% of the protein which is high-density lipoprotein. They are the proteins that attach with lipids to form lipoproteins in your body. They help in transporting lipids through lymphatic and circulatory systems in your body. They are synthesized in the liver which is controlled by multiple factors such as dietary composition, hormones such as insulin, glucagon, thyroxin, estrogens, and androgens and alcohol intake, and various drugs like statins and niacin.
Apo-A1 activates the enzymes that load cholesterol from the tissues into high-density lipoprotein (HDL) and allows it to be recognized by the receptors present in your liver. There are two forms of apolipoprotein A: apo A-I and apo A-II. Apo A-I is found in a greater proportion than apo A-II. The concentration of apo A-I can be measured directly and tends to rise and fall with HDL levels in your system.
Who should get the test?
There are signs which are commonly observed and indicate the requirement of this test. They are heartburn or indigestion and pain in your arm more commonly the left arm but could be either arm. You might frequently experience shortness of breath, headaches, upper back pain, and general malaise. You might also feel body pain, squeezing sensation of the chest, jaw pain, toothache, nausea, discomfort, and sweating.
Why is the test needed?
Your doctor might prescribe an apo A-I test to diagnose inherited or acquired conditions that cause Apo A-I deficiencies. This helps evaluate people with a family history of heart diseases and high cholesterol and triglycerides or low HDL levels. You can monitor the effectiveness of lifestyle changes and lipid treatments through this. It might be measured when you have a personal or family history of abnormal lipid levels. It might be ordered when your healthcare practitioner is trying to determine the cause of your high cholesterol and suspects that it can be due to a disorder causing apo A-I deficiency.
Your doctor might also order this to check an apo B/apo A-I ratio as a risk indicator to evaluate the bad and good cholesterol. You might get this test done if you underwent lipid-lowering treatment or lifestyle changes such as decreased dietary fat and increased regular exercise to monitor the effectiveness of the changes. This test assesses survival rate or risk factors in individuals who have suffered prior heart attacks, peripheral vascular diseases, and hyperlipidemia. Apo A-1 recycles cholesterol from the tissues back to the liver for further processing. It keeps your arteries clear of plaque-forming cholesterol.
What does the test result mean?
The results of the test are interpreted as follows:
Gender Reference Range
Male 94-178 mg/dL
Female: 101-199 mg/dL
Interpretation
- Low levels of ApoA1 indicate an increased risk of atherosclerotic cardiovascular disease.
- ApoA1 below 25 mg/dL may aid in the detection of a genetic disorder such as Tangier disease.
- ApoA1 is often interpreted as a ratio with apolipoprotein B (ApoB).
How is the test done?
A blood sample is drawn from a vein in your arm. No special preparation is required for this test. However, this test might be performed at the same time as a complete lipid profile so fasting of at least 12 hours may be required.
