GGT
Gamma-glutamyltransferase (GGT) is an enzyme found on the surface of cells in the liver, bile ducts, kidneys, and pancreas. It plays a role in glutathione metabolism and the transport of amino acids across cell membranes. GGT is the most sensitive enzymatic marker for biliary tract disease and alcohol-related liver damage.
Why it matters: GGT is elevated in a wide range of liver and biliary conditions, making it a sensitive but non-specific marker. It is particularly valuable for detecting alcohol-induced liver damage (often elevated before ALT/AST) and for distinguishing hepatic from bone sources of elevated ALP. Elevated GGT also independently predicts cardiovascular mortality.
May increase with:
May decrease with:
What is GGT?
Gamma-glutamyltransferase (GGT) is an enzyme found on the surface of cells in the liver, bile ducts, kidneys, and pancreas. It plays a role in glutathione metabolism and the transport of amino acids across cell membranes. GGT is the most sensitive enzymatic marker for biliary tract disease and alcohol-related liver damage.
What might a high or low GGT mean?
GGT is elevated in a wide range of liver and biliary conditions, making it a sensitive but non-specific marker. It is particularly valuable for detecting alcohol-induced liver damage (often elevated before ALT/AST) and for distinguishing hepatic from bone sources of elevated ALP. Elevated GGT also independently predicts cardiovascular mortality.
What is the typical reference range for GGT?
The general-population reference range shown here is < 73 U/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
What can affect GGT?
It may be higher with: Alcohol consumption (most sensitive marker), Bile duct obstruction, Fatty liver and NASH, Medications (anticonvulsants, warfarin), Pancreatic disease, Diabetes and metabolic syndrome, Obesity, Smoking. It may be lower with: Alcohol cessation (normalizes in 2-6 weeks), Weight loss, Coffee consumption (strong inverse association), Mediterranean diet, Exercise, Treating biliary obstruction, Reducing hepatotoxic medications.