What is Apolipoprotein B?
Apolipoprotein B is an essential component of low-density lipoprotein (LDL) or bad cholesterol and other lipoproteins, it plays a vital role in the transportation of cholesterol to the tissues, lipid metabolism, and helps in the prevention of invasive bacteria. Apolipoprotein B is present in two forms in the body including;
- ApoB100 is primarily produced in the liver.
- ApoB48 is primarily produced by the intestine and is found in chylomicrons.
Apolipoprotein B test is conducted for the measurement of the amount of apolipoprotein B in the blood. This test is more effective than the traditional lipid panel test as it gives highly accurate and direct results. High levels of apolipoprotein B are suggestive of higher risks of cardiovascular disorders.
How is the Test Performed?
The apolipoprotein B test is a simple blood test that involves the collection of blood samples by standard blood draw procedure.
Preparation
- Fasting of 8 to 12 hours is typically required for the test as it is performed alongside LDL-C, HDL-C, etc.
- If you are taking any medications inform your healthcare provider as he might suggest you avoid certain medications before the test.
- According to your health condition your healthcare provider may give special instructions.
Collection
- Blood is collected by a procedure called venipuncture. It involves the drawing of blood from a vein using a needle.
- The procedure is performed by a trained phlebotomist.
- Pressure is then applied to the site from where the blood was drawn to prevent any bleeding.
- The blood sample is then placed in a chemically treated tube provided by the laboratory to prevent the degradation and contamination of the sample.
- The sample is then sent to the laboratory for further analysis.
Lab analysis
The sample is analyzed in the laboratory by a highly experienced technician using advanced immunoassay techniques such as nephelometry or turbidimetry for accurate measurement of apolipoprotein B in the blood.
What are the symptoms that prompt this test?
The Apolipoprotein B test is recommended when an individual is exhibiting symptoms of risks associated with cardiovascular disorders or lipid metabolism disorders.
Cardiovascular Symptoms
- Discomfort while exertion
- Chest
- Shortness of breath
- Fatigue
- Sudden dizziness
Dyslipidemia (Elevated plasma cholesterol, Triglycerides, HDL-C)
- Weight gain without known reason
- Difficulty losing weight
- Xanthomas; deposition of cholesterol under the skin
- Appearance of white or grey rings around the cornea
What are Normal Ranges for This Test?
The normal values for apolipoprotein B vary according to age, sex, and individual health factors. The generally accepted reference range is given below;
Adult Male – 66 to 133 mg/dL
Adult Females – 60 to 117 mg/dL
**The above-mentioned values are standard guidelines only and vary according to the methodology used by different laboratories. Always consult your healthcare provider for an accurate interpretation of the results.**
What Happens if Test Results Show Abnormal Levels?
Abnormal levels of apolipoprotein B levels are indicative of disorders associated with lipid metabolism and cardiovascular disorders. Elevated levels of Apo-B protein are generally a concern as it indicates that an increased number of atherogenic lipoproteins such as low-density lipoproteins or bad cholesterol, VLDL, and IDL are present in the blood. The healthcare provider may suggest the following in cases of high and low levels of apolipoprotein B levels.
High Apolipoprotein B Levels
- Assessment of lipid parameters including total cholesterol, LDL, HDL, and triglycerides.
- Dietary changes
- Exercise and increased physical activity for weight management
- Medication
Low Apolipoprotein B Levels
- It is a rare condition and indicates malabsorption, genetic disorders such as abetalipoproteinemia, and liver disorders.
- Further diagnostic tests are recommended for the identification of underlying conditions.
