Elevated levels of the liver enzyme gamma-glutamyl transpeptidase, or GGT, may be caused by habits and conditions that damage the liver, including overconsumption of alcohol and drugs, hepatitis, loss of blood flow to the liver and cirrhosis of the liver, according to Healthline. Heart failure can also raise levels of GGT.
Tests that are conducted to determine GGT levels cannot diagnose medical conditions on their own, explains Healthline. They only indicate liver damage is present, prompting the physician to order additional tests for the patient. Because GGT levels tend to fluctuate, and minimal drinking habits can cause temporary liver damage, physicians may need to conduct second tests at later times.
Complications with the liver or bile ducts are indicated if GGT levels are elevated alongside elevated levels of alkaline phosphatase, or ALP, which is another liver enzyme, states Healthline. GGT levels may be tested if ALP levels are also elevated because high ALP levels with normal GGT levels can indicate the presence of bone disease.
The GGT enzyme is a molecule that transports other molecules through the bloodstream, notes Healthline. This function is what makes the GGT enzyme essential for helping the liver filter out the harmful effects from drugs, alcohol and other toxins. The enzyme can also be found in the pancreas, kidneys and spleen.