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Aspartate aminotransferase (AST)

Aspartate aminotransferase (AST) is an enzyme the body needs to function properly. It is found mainly in the liver, heart, and muscles. When these organs are diseased or damaged, their cells release AST, raising AST levels in the blood.

What is the purpose of this test? This test is mainly used for the following purposes:
  • To detect liver damage or monitor its progression
  • To monitor medications that may affect the liver
How to prepare?
  • Avoid intense physical exertion the day before and the day of the test.
  • No further preparation is required.
Reference values*
  • 15-37 UI/L
Associated tests Related tests include the following:
How is it done? Blood sample, usually taken from a vein in the arm.
How long before I get the results? Results are usually ready in a day. It may take longer to receive your results.
* These values are presented for information purposes only. As different laboratories may have different target values, the lab report usually specifies the values used for the test. It should also be noted that test results must be interpreted based on factors such as age, sex, and health condition. Values outside of this range may be considered normal for some individuals.

What does an abnormal test result mean?

High values of AST:

  • Liver damage due to a disease (e.g., hepatitis, cirrhosis, mononucleosis) or medication
  • Heart damage (e.g., heart attack, heart failure)
  • Muscle pain
  • Alcohol abuse
  • Pancreatitis

Medications that may affect test results

The use of certain medications can influence test results. Here are a few examples:

  • Certain cholesterol medications (e.g., statins)
  • Certain antibiotics (e.g., cephalosporins, tetracyclines)
  • Acetaminophen
  • Chemotherapy
  • Methotrexate
  • Isotretinoin

Factors that can interfere with test accuracy

Destruction of red blood cells (hemolysis) and intense exercise before the test may cause falsely high AST results.

What you should know before going for this test

When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.

© Copyright Vigilance Santé

The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.

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