Gamma-glutamyl Transferase (GGT) Test

The gamma-glutamyl transferase (GGT) test is a blood test used to measure the level of GGT, an enzyme found in many organs, particularly in the liver. The test is also known as gamma-glutamyl transpeptidase.

Purpose

The primary purpose of the GGT test is to assess liver damage or disease, such as hepatitis, cirrhosis, or liver cancer. It can also be used to monitor the progression of liver disease and the effectiveness of treatment.

How the Test is Performed

A blood sample is drawn from a vein in the arm, usually using a needle and syringe. The sample is then sent to a laboratory for analysis.

Interpretation of Results

The normal range for GGT varies depending on the laboratory and the individual's age and sex. Generally, the normal range is:

• Adults: 0-55 units per liter (U/L)
• Children: 0-24 U/L

Elevated GGT levels may indicate liver damage or disease, such as:

• Hepatitis
• Cirrhosis
• Liver cancer
• Alcoholic liver disease
• Non-alcoholic fatty liver disease (NAFLD)
• Bile duct obstruction

Factors that Can Affect GGT Levels

Certain factors can affect GGT levels, including:

• Age: GGT levels tend to increase with age
• Sex: Men tend to have higher GGT levels than women
• Obesity: Obesity can lead to elevated GGT levels
• Medications: Certain medications, such as anticonvulsants and antibiotics, can affect GGT levels
• Alcohol consumption: Heavy alcohol consumption can lead to elevated GGT levels

Clinical Significance

The GGT test is often used in conjunction with other liver function tests, such as the alanine transaminase (ALT) and aspartate transaminase (AST) tests, to diagnose and monitor liver disease. Elevated GGT levels can indicate liver damage or disease, but they do not necessarily confirm a specific diagnosis.

Frequently Asked Questions (FAQs)

What is the Gamma-glutamyl transferase (GGT) test?
A blood test that measures the level of GGT enzyme in the blood.

Why is the GGT test ordered?
To assess liver damage or disease, and to monitor alcohol use or pancreatitis.

What does a high GGT level indicate?
May indicate liver disease, bile duct disease, or alcohol use, among other conditions.

Can a low GGT level be significant?
Generally, low levels are not typically considered clinically significant.

How is the GGT test performed?
A blood sample is drawn from a vein in the arm and sent to a lab for analysis.

Are there any preparations needed for the GGT test?
Typically, no special preparation or fasting is required, but this may vary.

What are normal GGT levels?
Vary by lab, but generally considered normal in adults if below 30-50 U/L.

Can medications affect GGT levels?
Yes, certain medications, such as anticonvulsants and antibiotics, may increase GGT levels.

Is the GGT test used to diagnose a specific condition?
Not typically used alone for diagnosis, but rather in combination with other tests and medical evaluation.

Are there any risks associated with the GGT test?
Risks are minimal, but may include bleeding or bruising at the blood draw site.