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Additional factors that alter GGT levels
Female patients have lower levels of gamma-glutamyltransferase than male patients, and female individuals tend to increase their levels with age.
Drinking alcohol is the most common factor that changes the GGT blood concentration. Thus, it is often recommended to abstain from drinking before testing for 24 hours minimum. In addition to that, patients may be asked not to drink or eat anything except water for eight hours before the test. This is because GGT levels go down during the process of digestion.
Certain drugs increase GGT levels. A doctor has to know what meds his patient is taking before the test. Common drugs that alter GGT levels include antibiotics, antidepressants, women contraceptives, anticoagulants, acetaminophen, and phenobarbital.
