GGT is a liver enzyme involved in the transport of amino acids and peptides into cells as well as glutathione metabolism. GGT is mainly found in liver cells and as such is extremely sensitive to alcohol use. Elevated GGT levels may be found in liver disease, alcoholism, obesity, bile-duct obstruction, cholangitis, and drug abuse. Decreased levels can be found in hypothyroidism, hypothalamic malfunction and very low levels of magnesium. Because both chronic alcohol consumption and obesity associated with metabolic abnormalities are increasing in Western societies, the concomitant occurrence of these factors is of considerable interest. In this scenario, advanced liver disease, including inflammation, fibrosis, cirrhosis, and liver cancer, may develop more rapidly. The determination of a normal serum GGT activity range needs to be reevaluated and adjusted to BMI to avoid wrong conclusions with respect to alcohol consumption.

GGT is an enzyme that metabolizes extracellular glutathione and can be induced by various xenobiotics, drugs, and ethanol. All these compounds, including free fatty acids and acetone, may also induce cytochrome P4502E1 (CYP2E1). GGT stands for gamma-glutamyl transpeptidase. Another liver test is called ALT.

GGT Level - GGT test - GGT blood test

Normal Adult Female Range: 0 - 45 U/L
Normal Adult Male Range: 0 - 65 U/L
     Elevated GGT level can occur due to obesity.

High GGT blood test predicts heart disease

Serum gamma-glutamyltransferase predicts non-fatal myocardial infarction and fatal coronary heart disease among 28 838 middle-aged men and women.
Eur Heart J. 2006 Jun 13;
Serum gamma-glutamyltransferase (GGT) concentration may be involved in atherosclerosis. This study examined if serum GGT predicted coronary heart disease (CHD), especially differentiating non-fatal myocardial infarction (MI) and fatal CHD event, among the general population or participants with type-2 diabetes. Conclusion: This study suggests an independent mechanism linking serum GGT to coronary heart disease. Even though the strength of association appeared to be modest among all subjects, stronger associations were observed among subjects aged <60 and among alcohol drinkers. Especially, measurement of serum GGT among type-2 diabetics may be helpful to predict the future risk of CHD.
 

GGT and Fatty Liver

Fatty liver is one of the most frequent liver conditions diagnosed in the Western world. Chronic alcohol consumption as well as overweight and obesity associated with insulin resistance and the metabolic syndrome are the major factors resulting in fatty liver. Alcoholic fatty liver as well as nonalcoholic fatty liver can progress to more advanced liver disease, including inflammation, cirrhosis, and liver cancer. From a public health perspective, the most successful approach to deal with these liver diseases is early detection and intervention instead of treating the complications of advanced liver disease. Early detection of fatty liver includes its noninvasive verification, mostly done by hepatic ultrasound, and identification of its cause, which includes the patient's history. Because it is sometimes difficult to obtain an exact history of alcohol consumption, laboratory markers of chronic alcohol misuse have been established and are frequently used. One of the best markers for chronic alcohol consumption is serum {gamma}-glutamyl transferase (GGT), which has a relatively high sensitivity and specificity. Because measurement of this enzyme is easy and inexpensive, it has generally been used for early detection of chronic alcohol misuse. However, serum GGT activity loses its specificity for alcohol in more advanced liver disease because its activity is elevated in hepatic inflammation and more advanced liver disease regardless of the cause. Although chronic alcohol consumption is the most frequent cause of elevated serum GGT activity, an increased activity of this enzyme can also be observed under medical treatment and in acute pancreatitis, myocardial infarction, hyperthyroidism, anorexia nervosa, certain muscle diseases, neurological disorders, porphyria cutanea tarda, and some malignancies. Recently, non alcoholic fatty liver disease has become an important issue in the United States and Europe because of the striking increase in overweight and obese persons in these countries. Because these persons frequently also have increased GGT activities, a differentiation between AFL and NAFL on the basis of serum GGT activity is difficult. Furthermore, overweight is sometimes the result of chronic alcohol ingestion, and FL often results from both ethanol consumption and metabolic abnormalities. Serum GGT activity is influenced not only by the amount of alcohol consumed but also by body mass index (BMI) and sex.

GGT liver Questions
Q. I have been benefiting a great deal from your newsletter. Gum Guggul, Bedellium gum". Would it affect the liver in a negative way if the GGT liver enzyme is high?
   A. We don't have specific info on guggul, GGT and liver enzymes so we don't know how guggul affects GGT or other liver enzymes.

Q. I read with interest your information on GGT enzyme in an internet article, and found it very interesting. I have been taking Red Yeast Rice to lower my cholesterol over the last two years (taken with Niacin and CoQ10). My medical physician has told me that this works on your liver in the same exact way that statin drugs do, and that I should be aware of that, even though it is a natural alternative to conventional cholesterol treatments such as Lipitor. My question is then, does taking Red Yeast on Rice affect the liver to raise GGT levels? A recent blood test showed good numbers in every other category, except elevated GGT level, which was 119 (range should be < 62). I am active and play in a men’s Basketball league. I have not eaten red meat for over 30 years, and mostly eat a lacto-avo vegetarian natural food diet. I do not have any other issues health-wise, and do not take any other substances other than the Red Yeast. I have not had alcoholic beverages for over 32 years (aside from an occasional non-alcoholic beer for taste). I know from your article that high GGT levels are primarily the result of alcoholism, so I can’t figure what else would be doing this aside from the Red Yeast.
   A. It is possible that red yeast rice could lead to elevated ggt level in some people. The best way to find out in your case is to stop the red yeast rice for a month or so and then retest the GGT liver enzyme level to see if it goes down. To confirm, you could restart the red yeast rice supplement and then retest a couple of months later to see if the GGT liver enzyme level goes up again.

Q. Hi, wanted to know is it possible for elevated GGT enzyme levels to go down on its own if alcohol consumption is completely stopped?
   A. If the elevated GGT level was due to alcohol overuse, and the alcohol is stopped, then there is every reason to expect the elevated GGT level would go down.

Q. I'm writing in regards to an article about GGT levels. I recently had blood work done and was told my GGT levels were higher than normal. I am wine drinker and have a good feeling it was from my alcohol consumption. On average, how long does it take for GGT levels to start dropping if alcohol consumption is stopped?
   A. It can take a few days or a few weeks for GGT levels to drop depending on how long you have been drinking alcohol, how much alcohol you have been drinking, the type of alcohol, the general health of your liver and body, other medicines or supplements you may be taking, (ex" acetaminophen can damage the liver), your age, diet, etc.
      Q. Thank you very much for the quick reply back. I started out with a GGT level of 75 last week and hit 61 this week on the GGT. I really appreciated this GGT information article because it was one of the deciding factors in me ending drinking.

Q. I had a high GGT count on my latest liver test blood work up in October 2007. I had been taking Prexige since January 2007 until yesterday when I tried to refill the prescription and was told it was taken off the market-I was told it could cause liver failure or damage. If this is so and I have stopped this med would the count go back down again?
   A. Prexige (lumiracoxib), by Novartis, had been approved in 2003 by the Medicines and Healthcare products Regulatory Agency (MHRA in the United Kingdom. Prexige was approved for symptomatic relief of osteoarthritis and* short-term relief of moderate to severe acute pain associated with primary dysmenorrhea, dental surgery, and orthopedic surgery. The potential damage to the liver from Prexige, or most medicines that can harm the liver, depends on each person's unique biochemistry, alcohol use, concurrent use of tylenol, stating drugs, or other drugs that harm the liver, dosage, frequency of use, and other factors. We don't have much experience with Prexige so we can't say how long the GGT levels will stay up.

Q. I have read your article on elevated GGT and it contains more information on GGT that I have heard from my personal physicians in 3 years. I have a GGT of 186, elevated. I am 6'33'' and 190 pounds, do not drink alcohol excessively, and have not had an alcoholic drink in 2008. I have been tested for fatty liver, hepatitis, and various other things - all proven to be negative. I eat well, exercise regularly and live a healthy lifestyle. My doctor wants to do a liver biopsy. Is it possible to have a genetically high GGT? Is it possible that a high GGT will have no underlying cause? Is it possible to have a high GGT and have nothing to worry about?
   A. It depends on how high the GGT level is. If it is slightly or moderately high, it is possible that there could be no serious underlying disease. If the GGT level is very high, then it is of concern and there could be a serious underlying condition. It also depends on how the GGT level is changing over time. There are no easy answers.
      Q. My GGT is 186 - and has been consistently 160-190 over the last several years.
         A. One has to take into account all other liver enzyme values, other blood tests, the physical exam, and overall medical health, diet, medications used, and not just rely on one out of range blood study.

Q. Can you summarize the liver test ggt and in which conditions there could be a high level of ggt in the blood?
   A. GGT blood levels may be elevated due to liver disease, hepatitis, gallstones, diabetes, pancreatic disease, kidney failure, alcohol misuse, certain prescription drugs, certain herbs and supplements or taking very high amounts of supplements, or a tumor.