Gamma-glutamyl transpeptidase (GGT) is an enzyme found in many body tissues, the most notable being the liver. A GGT test may be used to determine the cause of elevated alkaline phosphatase (ALP). GGT and ALP are both elevated in disease of the bile ducts and in some liver diseases, but only ALP will be elevated in bone disease. Comparing the two test results can help determine if liver or bone disease is the cause of abnormal enzyme levels. For this reason, a GGT test is often run alongside other tests when a liver issue is suspected, such as: ALP, ALT, AST, and bilirubin tests, to differentiate between liver disease, bile duct disorders, and bone disease. Some signs and symptoms of liver damage include:
- Weakness, fatigue
- Loss of appetite
- Nausea and vomiting
- Abdominal swelling / pain
- Jaundice (yellowing of the skin / eyes)
- Dark urine, light-colored stool
- Itching
Alcohol abuse is also known to affect GGT levels; therefore, GGT tests are sometimes ordered to monitor alcohol-dependency treatments and compliance with treatment programs in those with a history of alcohol abuse.
Decreased GGT levels are associated with vitamin B6 and magnesium deficiency.
A low or normal GGT test indicates that liver damage in unlikely or the person hasn’t consumed any alcohol recently.
It is worth noting that use of clofibrate and oral contraceptives can decease GGT levels.
Understand and improve your laboratory results with our health dashboard.
Upload your lab reports and get interpretation today.
Our technology helps to understand, combine, track, organize, and act on your medical lab test results.
An elevated GGT level indicates that something is damaging the liver but does not indicate specifically what. Generally, the higher the GGT level the greater the damage to the liver. Therefore, a high GGT level typically warrants further testing. Elevated levels may be due to liver diseases (such as hepatitis or cirrhosis), or they may be due to other conditions (such as congestive heart failure, diabetes, or pancreatitis). As mentioned above, alcohol abuse and smoking can also cause elevated GGT, as well as drugs that are toxic to the liver, including: phenytoin, carbamazepine, and barbiturates. In addition, use of many other prescription and non-prescription drugs, including NSAIDs, lipid-lowering drugs, antibiotics, stomach acid reducers, antifungal agents, antidepressants, and testosterone can increase GGT levels.
It is worth noting that GGT levels increase with age in women, but not in men, and are always somewhat higher in men than in women.
Interpret Your Lab Results
Upload your lab report and we’ll interpret and provide you with recomendations today.
Get StartedGet Started With Our Personal Plan
Advanced Plan
Unlimited Plan
Are You a Health Professional?
Get started with our professional plan
Welcome to Healthmatters Pro.
Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more
Pro Plan
for health professionals
$45 per month
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.
Abnormal Protein Band 1, Actin (Smooth muscle) Antibody (IgG), Alanine-aminotransferase (ALT, SGPT), Albumin, Serum, Albumin/Globulin (A/G) Ratio, Alkaline Phosphatase (ALP), Alpha-1-Globulin, Serum, Alpha-2-Globulin, Serum, Aspartate-aminotransferase (AST, SGOT), Beta Globulin, Serum, Beta-1-Globulin, Serum, Beta-2-Globulin, Serum, Bilirubin Direct, Bilirubin Indirect, Bilirubin Total, Gamma Globulin, Serum, Gamma-Glutamyl Transferase (GGT), Globulin, Serum, Mitochondrial (M2) Antibody, Pre-Albumin, Prealbumin, Total Protein, Serum