What does it mean if my aspartate aminotransferase is high

AST (SGOT) - Hepatitis C for Patients

AST, or aspartate aminotransferase, is one of the two liver enzymes. It is also known as serum glutamic-oxaloacetic transaminase, or SGOT. AST is a protein made by liver cells. When liver cells are damaged, AST leaks out into the bloodstream and the level of AST in the blood becomes elevated. AST is different from ALT because AST is found in parts of the body other than the liver—including the heart, kidneys, muscles, and brain. When cells in any of those parts of the body are damaged, AST can be elevated.

Explanation of test results:

A high AST level often means there is some liver damage, but it is not necessarily caused by hepatitis C. A high AST with a normal ALT may mean that the AST is coming from a different part of the body. It is important to realize that the AST level in most patients with hepatitis C goes up and down. The exact AST level does not tell you how much liver damage there is, or whether the liver is getting better or worse, and small changes should be expected. However, for patients receiving treatment for hepatitis C, it is helpful to see if the AST level goes down.

Other things to know:

• The AST level is not as helpful as the ALT level for checking the liver.
• Many patients with hepatitis C will have a normal AST level.
• Patients can have very severe liver disease or cirrhosis and still have a normal AST level.

Definition

The aspartate aminotransferase (AST) blood test measures the level of the enzyme AST in the blood.

Alternative Names

Aspartate aminotransferase; Serum glutamic-oxaloacetic transaminase; SGOT

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is needed.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

AST is an enzyme found in high levels in the liver, heart, and muscles. It is also found in lesser amounts in other tissues. An enzyme is a protein that causes a specific chemical change in the body.

Injury to the liver results in release of AST into the blood.

This test is mainly done along with other tests (such as ALT, ALP , and bilirubin) to diagnose and monitor liver disease.

Normal Results

The normal range is 8 to 33 U/L.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

An increased AST level is often a sign of liver disease. Liver disease is even more likely when the levels of substances checked by other liver blood tests have also increased.

An increased AST level may be due to any of the following:

• Scarring of the liver (cirrhosis)
• Death of liver tissue
• Heart attack
• Too much iron in the body (hemochromatosis)
• Swollen and inflamed liver (hepatitis)
• Lack of blood flow to the liver (liver ischemia)
• Liver cancer or tumor
• Use of drugs that are toxic to the liver, especially alcohol use
• Mononucleosis ("mono")
• Muscle disease or trauma
• Swollen and inflamed pancreas (pancreatitis)

AST level may also increase after:

• Burns (deep)
• Heart procedures
• Seizure
• Surgery

Pregnancy and exercise may also cause an increased AST level.

Risks

There is little risk involved with having your blood taken. Veins vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Risks associated with having blood drawn are slight, but may include:

• Fainting or feeling lightheaded
• Excessive bleeding
• Multiple punctures to locate veins
• Hematoma (blood collecting under the skin)
• Infection (a slight risk any time the skin is broken)

References

Chernecky CC, Berger BJ. Aspartate aminotransferase (AST, aspartate transaminase, SGOT) - serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:172-173.

Pincus MR, Tierno PM, Gleeson E, Bowne WB, Bluth MH. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 21.

Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 73.

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