GGT test is often used along other liver function tests to diagnose liver problems in hospitals. Though mainly found in the liver, gamma-glutamyltranspeptidase enzyme, equally referred to as GGT (Gamma-glutamyltransferase), and is found throughout the body.
Enzymes are a kind of cellular protein that act as catalysts, allowing certain body processes to occur. There are many enzymes in your body which have vital functions.
In this complimentary blog post, we will take a good look at what a GGT test is, why you need it and what GGT tests results mean.
What is the GGT (gamma glutamyltransferase) test?
The amount of GGT (gamma glutamyltransferase) in your blood is measured using GGT (gamma-glutamyltransferase) test. GGT is an enzyme found especially in the liver, but also can be detected throughout your body. GGT can enter your bloodstream when your liver is damaged.
Elevated levels of blood GGT may be a sign of harm to your bile duct or liver disease. Tubes carrying bile inside and outside of the liver are called bile ducts. Bile is a fluid produced by your liver and is essential for digestion.
A specific cause of liver disease can’t be diagnosed by a GGT test. Therefore, it is often done with or after other LFT test (liver function diagnostic tests), the most common being ALP (alkaline phosphatase) test. ALP generally used to diagnose liver and bone diseases is a different type of liver enzyme.
Other names: Gamma-GT, GTP, GGTP, gamma-glutamyl transpeptidase.
What is the purpose of a GGT test?
The cause of a higher than normal ALP GGT test result can be determined with a GGT diagnostic test. Only ALP is increased in bone diseases though both ALP and GGT are increased in some liver diseases and bile duct diseases. So, if the GGT test results is within the reference range and the ALP result is elevated, a bone disease is most likely the cause.
The GGT test is often times used to detect bile duct obstruction and liver disease. It is often done as a follow-up to or along with other liver tests such as ALP, aspartate aminotransferase (AST) test, bilirubin, and alanine aminotransferase (ALT). In general, elevated GGT levels do not specifically indicate a condition that can causes liver damage but simply indicates that the liver damaged.
The GGT test can equally be used to detect chronic alcohol abuse (high in about 75% of chronic drinkers) and if you are receiving treatment for alcoholism or alcoholic hepatitis, it can help to monitor alcohol abuse and/or use.
Why you need a GGT test?
If you have symptoms of liver disease, you may need a GGT test. Symptoms of liver disease include:
- Loss of appetite
- Stomach bloating or pain
- Vomiting and nausea
- Fatigue
- Weakness
- Jaundice (a condition that causes yellowing of your skin and eyes)
You may equally need this blood test if you have high or low results on other liver function tests and/or ALP test.
High levels of ALP
Your doctor may order a GGT test to access the cause of a high alkaline phosphatase (ALP) levels. ALP and GGT may be elevated if you have certain types liver diseases or bile duct problems. However, only the ALP value increases in case of bone disease. Therefore, if you’re having an elevated ALP but normal GGT blood levels, it is likely that the reason of increased ALP test values is not liver disease but a bone disease.
Liver conditions
Your doctor can use the GGT test to diagnose the signs and symptoms of likely liver conditions. GGT test can form an essential part of your diagnostic process, even though your doctor cannot diagnose a condition based on the GGT levels alone. Doctors often order the GGT test along with other tests, for instance ALP, AST, ALT blood test, and bilirubin blood tests, to differentiate between bone diseases, bile duct or liver disorders.
Signs and symptoms of liver diseases include:
- Jaundice (whites of your eyes and yellowing of your skin).
- Fatigue (tiredness).
- Appetite loss.
- Vomiting and/or nausea.
- Stomachache.
- Skin itch
Alcohol use (AU) disorder
Healthcare professionals can use this test to detect this condition early, since about 75 percent of people with alcohol dependence have elevated of GGT blood levels. You doctor may order a GGT test to monitor your alcohol intake If you are being treated for alcoholic hepatitis or alcohol dependence.
Associated risks with GGT blood test
The risk of blood tests is very low. You may feel bruising or pain at the injection site, though most symptoms rapidly go away.
Who performs the GGT test?
Any doctor with experience in blood samples can perform this task. However a doctor known as a phlebotomist normally take your blood samples, including the blood for GGT test. The phlebotomist later sends the blood sample to a laboratory, where medical laboratory technician prepare the blood sample and perform tests on what is called an analyzer machine.
Doing a gamma glutamyl transferase blood test
A GGT blood test is performed in a medical center or laboratory, where your blood sample is drawn from a vein in the arm.
What happens before a GGT blood test?
Given that GGT blood levels drop after eating, you doctor may be asked to fast (no drink or food except water) for a minimum of eight hours before your GGT test. You may equally be asked beforehand to stop taking certain prescription medications or drinking alcohol.
What happens during a GGT blood test?
During a GGT blood test, your doctor collects a blood sample from a vein in your forearm. A tiny needle is inserted into a desired vein and your blood is collected in the attached vial, once a suitable vein has been found and the donor site properly cleaned. A GGT test blood draw procedure often last less than 5 minutes.
What happens after a GGT test?
To reduce bleeding, after a sample of your blood is taken, the phlebotomist will apply a bandage or gauze. Pain and bruising at the needle insertion site may occur, however the risk of drawing blood is minimal. After the blood draw, there are no restrictions on normal activities.
What does your GGT tests results mean?
GGT (gamma-glutamyltransferase) test results, including other blood test reports, typically contain the following statistics:
- What is measured in the blood (the blood test name)?
- The measure or number of your GGT test results.
- The normal GGT test levels or range.
- Information indicating whether your GGT test results are abnormal or normal, low or high.
What is the normal range for GGT test?
From one laboratory to the other, the normal range for GGT (gamma-glutamyltransferase) varies. Five to 40 units per litter of your blood (U/L) is the general reference range for adults. Since GGT normal ranges can vary from laboratory to laboratory, it is essential to review your GGT blood test report to determine the laboratory-specific reference range.
It is essential to know that GGT blood values are, on an average, slightly elevated in males and biological male from birth than in those assigned female from birth and biological females. Furthermore, GGT blood levels increases with increasing age in those assigned female from birth and females, but not in those assigned male from birth and males.
It is possible that you have not consumed alcohol or have liver disease if your GGT test results are normal or low.
It could be a sign of liver damage if your results show higher GGT blood levels than the normal range. Your condition may be caused by one of the following:
- Diabetes
- Heart failure
- Side effect of a medication. In some people, some medicines can result to liver damage.
- Hepatitis
- Cirrhosis
- Alcohol use disorder
- Pancreatitis
Your GGT test results cannot tell you exactly what condition is causing the liver damage. Generally, the higher your GGT blood level, the more severe the liver damage.
If your test results show that your GGT blood level is low or normal, you most likely do not have a liver disease.
Your GGT test results can equally be compared to your ALP test results. The ALP blood test can help diagnose your bone diseases. In general, the results may show:
- Elevated readings of GGT and ALP indicate that your symptoms are most likely not due to bone disease but to liver disease.
- Normal or low GGT level and a high ALP levels means that you are more likely to have bone disease.
Please consult your doctor if you have any questions about your GGT test results.
When to call your doctor?
If you have liver damage symptoms, such as stomach pain or jaundice, call your doctor.
Contact your doctor if are experiencing symptoms that worry you or you have been diagnosed with liver disease.
Message from BigManLab
It can be stressful reading abnormal GGT test results. Keep in mind that elevated GGT (gamma-glutamyl transferase) blood levels don't always entails the presents of a disease or that you need to be treated. About every twenty healthy people have GGT test result levels that are abnormal. When interpreting your GGT test results, your doctor will consider several factors and will equally advise you if further testing is needed to identify the root cause of the abnormal GGT reading. Do not shy away from asking your doctor questions if you have any. Their job is to aid you!
