Quick Look

The liver, heart, pancreas, muscles, and other tissues in your body contain the enzyme aspartate transferase (AST). Healthcare providers frequently include an AST blood test in a liver panel and a comprehensive metabolic panel to assess liver health.

Other Names

Aspartate aminotransferase (AST).

Serum glutamic-oxaloacetic transaminase.

SGOT.

Aspartate transaminase.

What is an AST test?

When cells sustain damage, they can release AST into your bloodstream. Elevated levels of AST in a blood sample may indicate an underlying medical condition, typically a liver condition, although not always.

Healthcare providers refrain from relying solely on the test for diagnosis, given that various liver conditions can elevate AST levels in the blood. Instead, an AST blood test is commonly integrated into a broader blood test panel, such as a  liver function test (LFT) or a comprehensive metabolic panel (CMP). These panels measure multiple aspects of your blood with a single sample, offering more comprehensive insights into your overall health.

When is the Aspartate Transferase test done?

To screen for, monitor, or aid in the diagnosis of liver conditions and other medical conditions, your healthcare provider might request a blood panel test, which includes an AST test.

Screening 

If you have risk factors for liver disease, such as heavy alcohol use, a family history of liver disease, diabetes, obesity, or using shared needles for drug injections, your healthcare provider may recommend screening with a liver panel blood test, which includes an AST test.

Even without specific risk factors, an AST test may be included in routine blood panel tests like a comprehensive metabolic panel, assessing your overall health.

Monitoring 

If you already have a liver condition, your healthcare provider may order an AST test, often as part of a panel, to track whether your condition is improving, worsening, or remaining stable, with or without treatment. If you’re taking medication that can affect your liver, your provider may also include an AST test and liver enzyme panel.

Diagnosis

Your healthcare provider might use an AST test when you exhibit signs and symptoms of potential liver problems. While AST levels alone cannot provide a definitive diagnosis, they play a crucial role in the diagnostic process.

Signs and symptoms of liver conditions encompass nausea, vomiting, abdominal pain, itchy skin, jaundice (yellowing of the skin and eyes), fatigue, and appetite loss

Test Preparation

• When your AST test is included in a comprehensive metabolic panel (CMP), it’s typically necessary to fast for 10 to 12 hours before the blood test. Fasting entails abstaining from eating or drinking anything except water.

• However, if you’re specifically undergoing an AST blood test or a hepatic function panel (HFP), fasting is generally not required.

• Regardless, your healthcare provider will provide specific instructions when ordering the bloodwork. It’s essential to adhere to their directions for accurate and reliable results.

• Various medications and supplements can impact AST levels, underscoring the importance of informing your healthcare provider about any drugs or dietary supplements you’re taking before undergoing the test. In certain situations, your healthcare provider might advise you to discontinue a medication before the test. However, it’s crucial to follow their guidance and only stop taking medication if explicitly instructed to do so by your healthcare provider.

Normal Range of Results

The normal range for aspartate transferase (AST) can differ from one laboratory to another. A common reference range for an AST blood test is 8 to 48 U/L (units per liter). It’s crucial to check your test result report to identify the specific reference range used by your lab, as these ranges may vary.

Additionally, there is no universally applicable AST range for all individuals. The normal AST level can be influenced by factors such as your age, sex, race, and weight. Your healthcare provider will take all these factors into account when interpreting your test results.

High Aspartate Transferase

An elevated AST level may serve as an indicator of a potential liver condition, especially if other liver blood tests also show abnormalities. While less common, increased AST levels can result from cell damage in other areas of the body.

A high AST level could be associated with various liver conditions, including:

• Alcohol-induced liver injury.
• Hepatitis (liver inflammation).
• Cirrhosis (scarring of the liver).
• Use of medications toxic to the liver.
• Liver tumor or liver cancer.
• Liver ischemia (insufficient blood flow to the liver, leading to tissue death).

Additionally, a heightened AST level might indicate conditions unrelated to the liver, such as:

• Hemochromatosis (excessive iron in the body, causing damage to the heart, liver, and pancreas).
• Heart attack (myocardial infarction).
• Mononucleosis (“mono”).
• Muscle disease.
• Pancreatitis.
• Temporary increases in AST levels can occur after events like deep burns, seizures, heart procedures, surgery, and intense exercise. Pregnant individuals may also experience elevated AST levels.

Importantly, a high AST test result doesn’t necessarily imply a medical condition, as other factors can influence AST levels. Your healthcare provider will consider various factors, including other blood test results and your medical history, in the comprehensive analysis of your results.

Note

It’s important to recognize that a high level of aspartate transaminase (AST) doesn’t automatically indicate a medical condition requiring treatment. Various factors can influence AST levels, and about 1 in 20 healthy individuals may have results outside the normal reference range. Your healthcare provider will guide you on whether further tests are necessary to pinpoint the cause of an abnormal level.

Don’t hesitate to ask your healthcare provider questions; they are there to assist you. Seeking clarification and understanding your health situation is an essential part of the healthcare process.

References

1. (N.d.). Retrieved from https://www.mayocliniclabs.com/test-catalog/overview/8360 
2. professional, C. C. medical. (n.d.). Retrieved from https://my.clevelandclinic.org/health/diagnostics/22147-aspartate-transferase-ast