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.