AST – SGOT (Aspartate Aminotransferase) Test
Sample Type: Serum
Also Known As: SGOT (Serum Glutamic-Oxaloacetic Transaminase)

Overview:
Aspartate Aminotransferase (AST), also known as SGOT, is an enzyme found primarily in the liver, heart, muscles, kidneys, and brain. It plays a vital role in amino acid metabolism by catalyzing the transfer of an amino group from aspartate to α-ketoglutarate, producing oxaloacetate and glutamate.

Purpose of the Test:
The AST test is commonly used to:

Evaluate liver health.

Diagnose liver diseases such as hepatitis, cirrhosis, or fatty liver.

Assess damage to the heart or muscles.

Monitor the progression of chronic liver conditions.

Help differentiate between cardiac and hepatic causes of symptoms like fatigue, jaundice, or abdominal pain.

Normal Reference Range:
Male: 10–40 U/L

Female: 10–35 U/L
(Values may vary slightly between laboratories)

High AST Levels May Indicate:
Liver disorders (hepatitis, cirrhosis, alcoholic liver disease)

Heart attack (myocardial infarction)

Muscle injury or disease

Pancreatitis

Hemolysis

Certain medications or toxins

Low AST Levels May Indicate:
Generally not clinically significant

Could suggest vitamin B6 deficiency in rare cases

AST vs ALT:
AST is often measured alongside ALT (Alanine Aminotransferase). While ALT is more liver-specific, AST can also be elevated due to non-hepatic causes (e.g., cardiac or muscle injury). The AST/ALT ratio helps differentiate between various causes of liver disease:

>2: Suggests alcoholic liver disease

<1: Suggests viral hepatitis or non-alcoholic fatty liver disease

Sample Collection:
Type: Blood (serum)

Preparation: Usually no fasting required

Collection: A healthcare provider draws blood from a vein, typically from the arm.

Clinical Considerations:
AST is released into the bloodstream when cells are damaged.

Elevated AST should be interpreted alongside other lab tests (e.g., ALT, ALP, bilirubin) and clinical findings.

Repeat testing may be required to monitor trends over time.

Conclusion:
The AST–SGOT test is a valuable diagnostic tool in assessing liver function and detecting tissue damage in organs rich in this enzyme. While it is not liver-specific, it remains a key marker in evaluating systemic diseases that involve cellular injury.