What causes high GGT levels? Procedure and what to expect. Share on Pinterest The GGT test is a simple and safe procedure that usually provides results within a couple of days. Risks and side effects. Adolescent depression: Could school screening help? Related Coverage. What is an alanine aminotransferase ALT blood test? Medically reviewed by J. Keith Fisher, M. What does a serum albumin test tell you?
Medically reviewed by Elaine K. Luo, M. Ten health risks of chronic heavy drinking. Medically reviewed by Stacy Sampson, D. What do abnormal ALP levels mean? What does the SGOT blood test mean? Gamma-glutamyl transferase GGT is a cell surface enzyme. It is located throughout the human body with the highest levels being in the kidneys, intestines, liver, prostate gland, and gallbladder.
Smaller amounts are found in the pancreas, lungs, testis, and thyroid gland. The liver produces most of the GGT in the blood [ 1 , 2 , 3 ]. Higher GGT levels also increase the risk of several diseases and may point to health problems.
This article will cover the functions of GGT, its role in diagnosing or predicting disease, and ways to lower GGT levels in the body. The primary function of GGT is the breakdown and recycling of glutathione , the most important antioxidant in the human body [ 4 , 5 ].
It increases the number of available amino acids especially cysteine , that are used to make glutathione inside the cell [ 6 ]. Tests for GGT measure the level of the enzyme in the blood. Age, gender, exercise, weight, pregnancy, diet, and medications can all influence GGT levels in the body [ 8 , 9 , 10 ]. The reference ranges for GGT levels vary between sources and laboratories.
Normal levels are dependent on age and sex. Generally, they are higher in adult males than in adult females. The reference ranges based on 1, alcohol abstainers are organized below one retrospective meta-analysis and one clinical study [ 11 , 12 ]:. Therefore, optimal levels of GGT are below the reference range midpoint based on age and gender.
Elevated levels of GGT point to high glutathione use in the body and oxidative stress. GGT alone does not directly cause a particular disease or disorder. However, high levels of GGT may be a sign of systemic cellular damage. GGT may increase oxidative stress , starting with the breakdown of glutathione and production of cysteinylglycine.
Other toxic molecules are then formed, leading to tissue, cellular, and DNA damage [ 13 , 15 ]. Once in the plaque, GGT can become pro-oxidant, injuring blood vessels via oxidative stress , and contribute to heart disease [ 40 , 29 , 41 ]. GGT is increased in patients with liver diseases, such as cirrhosis, hepatitis, and fatty liver.
These conditions are caused by a number of factors, including drug and alcohol abuse, toxins, or viruses [ 42 , 43 , 44 , 45 , 46 , 47 ]. GGT levels are used with other liver enzyme tests to diagnose liver disease. Elevated levels of both enzymes point to a liver or biliary tract disease. High levels of GGT are also found in patients with biliary tract disease cholestasis.
Like with liver disease, GGT is used in combination with additional tests, such as alkaline phosphatase ALP , for diagnosing biliary tract disease [ 16 ]. Prolonged alcohol use raises GGT levels. In some cases, additional tests may be conducted to identify alcohol abuse [ 17 , 18 , 19 ]. Increased levels of GGT in combination with another marker CDT were better at predicting alcohol abuse than either test alone [ 20 ]. Cigarette smoking has also been linked to elevated GGT levels.
Even though renal tissue has the highest level of GGT, the enzyme present in the serum appears to originate primarily from the hepatobiliary system, and GGT activity is elevated in any and all forms of liver disease. It is highest in cases of intra- or posthepatic biliary obstruction, reaching levels some 5 to 30 times normal. GGT is more sensitive than alkaline phosphatase ALP , leucine aminopeptidase, aspartate transaminase, and alanine aminotransferase in detecting obstructive jaundice, cholangitis, and cholecystitis; its rise occurs earlier than with these other enzymes and persists longer.
Only modest elevations times normal occur in infectious hepatitis, and in this condition, GGT determinations are less useful diagnostically than are measurements of the transaminases. High elevations of GGT are also observed in patients with either primary or secondary metastatic neoplasms. Elevated levels of GGT are noted not only in the sera of patients with alcoholic cirrhosis but also in the majority of sera from persons who are heavy drinkers. Studies have emphasized the value of serum GGT levels in detecting alcohol-induced liver disease.
Elevated serum values are also seen in patients receiving drugs such as phenytoin and phenobarbital, and this is thought to reflect induction of new enzyme activity. Editorial team. How the Test is Performed A blood sample is needed. How to Prepare for the Test The health care provider may tell you to stop taking medicines that can affect the test. How the Test will Feel When the needle is inserted to draw blood, some people feel moderate pain.
Why the Test is Performed GGT is an enzyme found in high levels in the liver, kidney, pancreas, heart, and brain. It may also be done to screen for, or monitor, alcohol use. What Abnormal Results Mean An increased GGT level may be due to any of the following: Alcohol use Diabetes Flow of bile from the liver is blocked cholestasis Heart failure Lack of blood flow to the liver Liver tissue death Liver cancer or tumor Lung disease Pancreas disease Scarring of the liver cirrhosis Swollen and inflamed liver hepatitis Use of drugs that are toxic to the liver.
0コメント