BLOOD ALANINE AMINOTRANSFERASE TEST (ALT)

Why is this test done? ALT is measured to detect certain liver problems and to follow their progression.
How to prepare:
  • A blood sample will be drawn to measure ALT.
  • There are no dietary restrictions prior to this test. You do not have to fast prior to this test.
Target Values:
  • Men: 10 – 32 U/L
  • Women: 9 – 24 U/L
    Target values are age-dependent. They can also vary from one lab to another.
Associated Tests: AST (aspartate aminotransferase), alkaline phosphatase and bililrubin are usually measured along with ALT.

 

General Information

Alanine aminotransferase is an enzyme required for the body’s proper functioning. It is found in several areas of the body, such as the muscles, the heart, the kidneys, but mostly in the liver. Increased blood levels are almost always associated with liver damage. ALT is essentially a marker of hepatocellular damage.

What does an abnormal test result mean?

If the result is to high
Various liver problems, such as viral or drug-induced hepatitis, liver cirrhosis or severe liver congestion can increase blood ALT levels. Excessive alcohol intake can also result in increased levels. Extenuating exercise can also induce elevated ALT levels.

Factors that can affect the result of the test

Upward
Obesity is linked with higher ALT levels. Certain drugs can increase alanine aminotransferase levels, such as:

  • ASA (Aspirin™);
  • acetaminophen (Tylenol™);
  • codeine;
  • morphine (Statex™);
  • meperidine (Demerol™);
  • chlordiazepoxide (Librium™);
  • ampicillin (Penbritine™);
  • cephalosporins;
  • tetracyclines;
  • certain anti-seizure drugs;
  • cloxacillin (Orbenin™);
  • nitrofurantoin (MacroBid™);
  • clofibrate (Atromid S™);
  • allopurinol (Zyloprim™);
  • indomethacin (Indocid™);
  • chlorpropramide (Diabinese™);
  • isoniazide (Isotamine™);
  • methotrexate;
  • oral contraceptives.

What you need to know before the test

Before going for blood tests, a procedure or other exam, it is best to always bring a list of all the drugs you take (prescription, OTC and natural health products). Unless told otherwise, you should take your medication as usual on the day of the test. When in doubt, ask your pharmacist for more information