What is GGT – Gamma Glutamyl Transpeptidase?
This is often elevated in those who use alcohol or other liver toxic substances to excess. It is an enzyme produced in many tissues as well as the liver. Like alkaline phosphatise AP, it may be elevated in the serum of patients with bile duct diseases. Elevations in serum GGT, especially along with elevations in alkaline phosphatase, suggest bile duct disease. Measurement of GGT is an extremely sensitive test, however, and it may be elevated in virtually any liver disease and even sometimes in normal individuals. GGT is also induced by many drugs, including alcohol, therefore often when the AP is normal a raised GGT can often (but not always) indicate alcohol use. Raised GGT can often be seen in cases of fatty liver and also where the patient consumes large amounts of aspartame (artificial sweetener) in diet drinks for example.
