What is the purpose of a Gamma-Glutamyl Transferase (GGT) test?

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Last updated: February 11, 2025 • View editorial policy

From the Guidelines

The primary purpose of a Gamma-Glutamyl Transferase (GGT) test is to assess liver health and detect potential liver damage or disease.

Key Uses of GGT Test

  • The GGT test is used to determine whether an elevated Alkaline Phosphatase (ALP) level is of hepatic or non-hepatic origin, as GGT is found in the liver and is a more specific indicator of liver disease than ALP 1.
  • It is also used to detect alcoholic liver disease (ALD), as GGT levels are often elevated in individuals with ALD, and is considered a sensitive marker for chronic alcohol misuse 2.
  • In addition, the GGT test can be used to monitor liver function in patients with drug-induced liver injury and to detect cholestatic liver disease 3.
  • GGT levels can also be used as a biomarker for alcohol use, although it is not specific for alcohol use and should be combined with other lab testing and clinical evaluation 4.

Interpretation of GGT Results

  • Elevated GGT levels can indicate liver damage or disease, but can also be influenced by other factors such as body mass index (BMI) and sex 2.
  • The sensitivity and specificity of GGT for detecting liver disease can vary depending on the population being tested and the presence of other liver enzymes or biomarkers 2, 4.
  • In patients with alpha-1 antitrypsin deficiency (AATD), repeatedly elevated serum liver tests, including GGT, have been associated with the development of liver disease 5.

From the Research

Purpose of Gamma-Glutamyl Transferase (GGT) Test

The primary purpose of a GGT test is to:

  • Indicate liver injury and excessive alcohol consumption 6, 7, 8, 9, 10
  • Serve as a marker of oxidative stress and antioxidant inadequacy 7, 8, 9, 10
  • Predict the risk of various chronic conditions and diseases, including: + Nonalcoholic fatty liver disease 6 + Vascular and nonvascular diseases 6, 7, 8 + Cardiovascular disease 7, 8, 10 + Diabetes 7, 8, 10 + Metabolic syndrome 7, 8 + Chronic kidney disease 9 + Neoplasia 9 + All-cause mortality 6, 7, 8, 9, 10

Clinical Applications of GGT Test

The GGT test has various clinical applications, including:

  • Diagnosis of liver injury 6, 9
  • Monitoring of liver disease 9
  • Assessment of cardiovascular risk 8
  • Prediction of mortality risk 7, 9, 10

References

Guideline

acr appropriateness criteria® abnormal liver function tests.

Journal of the American College of Radiology, 2023

Research

Gamma-glutamyltransferase-friend or foe within?

Liver international : official journal of the International Association for the Study of the Liver, 2016

Research

Gamma-Glutamyl Transferase (γ-GT) - an old dog with new tricks?

Liver international : official journal of the International Association for the Study of the Liver, 2022

Research

Gamma glutamyl transferase.

Critical reviews in clinical laboratory sciences, 2001

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.