What is GGT?

What is GGT?

GGT is concentrated in the liver, but it’s also present in the gallbladder, spleen, pancreas, and kidneys. GGT blood levels are usually high when the liver is damaged. This test is often done with other tests that measure liver enzymes if there’s a possibility of liver damage.

What is the meaning of the GGT blood test?

Gamma-glutamyltransferase (GGT) is primarily present in kidney, liver, and pancreatic cells. Small amounts are present in other tissues.

The GGT test may be used to determine the cause of elevated alkaline phosphatase (ALP). Both ALP and GGT are elevated in disease of the bile ducts and in some liver diseases, but only ALP will be elevated in bone disease. Therefore, if the GGT level is normal in a person with a high ALP, the cause of the elevated ALP is most likely bone disease.

The GGT test is sometimes used to help detect liver disease and bile duct obstructions. It is usually ordered in conjunction with or as follow up to other liver tests such as ALT, AST, ALP, and bilirubin. In general, an increased GGT level indicates that a person’s liver is being damaged but does not specifically point to a condition that may be causing the injury.

GGT can be used to screen for chronic alcohol abuse (it will be elevated in about 75% of chronic drinkers) and to monitor for alcohol use and/or abuse in people who are receiving treatment for alcoholism or alcoholic hepatitis.

What are normal and optimal GGT Level?

A low or normal GGT test result indicates that it is unlikely that a person has liver disease or has consumed any alcohol.

Reference Values:

Males

1-6 years: 7-19 U/L

7-9 years: 9-22 U/L

10-13 years: 9-24 U/L

14-15 years: 9-26 U/L

16-17 years: 9-27 U/L

18-35 years: 9-31 U/L

36-40 years: 8-35 U/L

41-45 years: 9-37 U/L

46-50 years: 10-39 U/L

51-54 years: 10-42 U/L

55 years: 11-45 U/L

> or =56 years: 12-48 U/L

Reference values have not been established for patients <12 months of age.

Females

>1 year: 6-29 U/L

Reference values have not been established for patients <12 months of age.

What do abnormal GGT Levels mean?

An elevated GGT level suggests that something is damaging the liver but does not indicate specifically what. In general, the higher the level, the greater the “insult” – or damage – to the liver. Elevated levels may be due to liver diseases, such as hepatitis or cirrhosis, but they may also be due to other conditions, such as congestive heart failure, diabetes, or pancreatitis. They may also be caused by alcohol abuse or use of drugs that are toxic to the liver.

A high GGT level can help rule out bone disease as the cause of an increased ALP level, but if GGT is low or normal, then an increased ALP is more likely due to bone disease.