The GGT test consists of measuring the enzyme gamma glutamyl transpeptidase in the blood to assess whether there is damage to liver tissue or bile ducts.
The GGT test or ‘gamma-glutamyl transpeptidase test’ is used to diagnose liver problems. It consists of measuring the concentration of said enzyme, gamma-glutamyl transpeptidase in the blood. It tends to change when the liver or bile ducts have some kind of damage.
However, it is a non-specific parameter, since it is also elevated in certain bone diseases or in alcoholics. Despite its non-specificity, it allows early detection of many pathologies. In addition, it is a simple and cost-effective examination. What exactly? How it is performed? All the details below.
What is the GGT test?
The GGT test It consists of measuring the levels of the enzyme gamma glutamyl transpeptidase in the blood. As explained in a publication Kids Health, this enzyme is produced in different parts of the body. Even so, the greatest synthesis occurs in the liver and gallbladder.
In the blood and other organs the levels are usually minimal. Therefore, when a high concentration is observed, it is possible to suspect some damage or disease. In particular, the abnormal GGT test indicates that the enzyme may be leaking from the liver into the blood.
At the same time, this alerts that the liver or bile ducts are showing damage. However, it must be considered that their levels are variable. For example, in babies they tend to be highest just after birth. In addition, the higher its concentration in the blood, the greater the liver damage suffered by the person.
When is the GGT test necessary?
The GGT test helps detect liver diseases. It also serves to diagnose those pathologies that affect the gallbladder and bile ducts. In fact, it is specifically used if harm is suspected as a result of substance or drug usesuch as alcohol or some drugs.
Alcohol consumption is one of the most harmful habits for the liver.
In itself, the test It is indicated when characteristic symptoms of these pathologies appear. To cite an example, jaundice, which is yellowish pigmentation of the skin and mucous membranes. It is produced by the accumulation of bilirubin, which cannot be eliminated by the liver.
Other symptoms that can lead to the performance of this test are the following:
- dark urine
- Very clear stools (acolia).
- Nausea and vomiting.
- Abdominal pain.
liver or bile duct damage
The GGT test can detect if there is damage to the liver or bile ducts. The reason is that gamma glutamyl transpeptidase levels are the first to increase if a person has an obstruction in this area.
For this reason, it is considered one of the most sensitive tests in relation to bile duct pathologies. It is part of the so-called ‘liver panel’, which brings together several tests that measure the most important liver enzymes (transaminases).
The most relevant transaminases, in addition to GGT, are the alanine aminotransferase (ALT) and the aspartate aminotransferase (AST). Also included in this test set are alkaline phosphatase and bilirubin. Each of them tends to rise more in certain diseases.
However, as with the GGT test, they are all non-specific parameters. The most important thing is that if the AST is high, it may be due to a bone or bile problem. In this case, if the GGT test is normal, it is possible to locate the damage in the bone system.
GGT test and chronic alcohol abuse
People who drink alcohol regularly tend to have an abnormal GGT test. The enzyme increases its blood levels. In fact, they are superior compared to people who drink sporadically although in larger quantities.
That’s why, it’s a test It helps to distinguish between chronic and acute alcohol abusers. It is useful if you want to know if a patient is still drinking or has really stopped.
How it is performed?
The GGT test is very easy to perform. According to a publication from the San Diego Hospital, it is not necessary to carry out any type of prior preparation. Despite this, it is advisable to fast for at least 8 hours before.
The doctor can make specific indications for each patient. For example, you may be asked to avoid certain drugs or alcohol before the test. This test is performed by obtaining a venous blood sample. Therefore, wearing a short-sleeved shirt makes removal easier.
The first thing is to clean the surface of the skin with an antiseptic. To make it easier to find the vein, an elastic band is placed like a tourniquet around the arm. This is how the veins are engorged with blood.
Then the needle is inserted. Typically, the sample is obtained from the inside of the elbow. It can also be removed from the back of the hand or even the foot. The blood is collected in a vial to be transported to the laboratory.
Once the necessary amount has been obtained, the elastic band is removed from the arm. The puncture area is pressed with cotton and the needle is removed. The GGT test will be performed in the laboratory from the blood obtained.
Obtaining the results and risks
Once the blood is obtained, it is taken to the laboratory and processed in a machine. The results are obtained quickly, in a matter of a few hours. The point is that if alterations are observed, more tests will be necessary.
In general, it is a simple, safe and practical procedure. As with any blood test, some problems can arise. For example, that a small bruise appears in the puncture area.
Patients may also become dizzy and faint while obtaining the blood. Similarly, there may be pain in the area where the needle was inserted. However, they are self-limiting and minor side effects.
What do the results mean?
The enzyme gamma glutamyl transpeptidase usually has very low concentrations in the blood. Typically, it is between 0 and 30 international units per liter (IU/L). As we have seen, the results are obtained in a few hours.
As pointed out by a publication Lab Test Online, the test may be abnormal—if GGT levels are high—or normal. When the concentration is high, indicates that there is a liver condition or in the bile ducts.
In addition, the higher its concentration, the greater the damage is usually. For example, it occurs in diseases such as hepatitis and cirrhosis. Even so, this elevation can also be seen in other pathologies. Some of them are the following:
- Metabolic syndrome.
- Pancreatitis.
- Diabetes.
- Heart failure.
- Drug or medication abuse.
Besides, a normal GGT test almost certainly rules out liver disease. It also helps to know whether or not someone has consumed alcohol. The main problem is that, as it is non-specific data, other additional tests will be needed.
You can even choose to repeat the test at another time if the parameters are at their limit. The reason is that the elevation of this enzyme can be somewhat transitory. For example, when drinking alcohol.
What to remember about the GGT test
The GGT test is a blood test that measures the levels of the enzyme gamma glutamyl transpeptidase. This is produced mainly in the liver and gallbladder. In blood, physiologically, its levels are usually almost undetectable.
For this reason, when its concentration increases, it indicates that there is damage to said organs. However, it is a very non-specific test. It usually requires other additional tests in order to find the cause and a diagnosis of certainty.
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