From the Guidelines
Elevated Gamma-Glutamyl Transferase (GGT) levels are primarily caused by liver disease, alcohol consumption, and certain medications, as indicated by the most recent study 1.
Causes of Elevated GGT
The causes of elevated GGT levels can be multifaceted, including:
- Liver disease, such as alcoholic liver disease, non-alcoholic fatty liver disease, and viral hepatitis
- Alcohol consumption, where even moderate drinking can raise GGT levels within hours
- Certain medications, including phenytoin, carbamazepine, barbiturates, and some antibiotics
- Other factors, such as pancreatic disease, heart failure, kidney disease, smoking, and some autoimmune conditions
Importance of GGT Elevation
GGT elevation is often detected during routine blood tests and may require further investigation to determine the underlying cause. The degree of elevation can provide clues about the severity of liver damage, with mild elevations (less than 3 times normal) often seen in fatty liver disease, while more significant elevations may indicate more severe liver damage or bile duct obstruction.
Clinical Approach
If you have elevated GGT, your healthcare provider may recommend lifestyle changes like reducing alcohol consumption, losing weight, or adjusting medications, depending on the identified cause, as suggested by 1. It is essential to monitor liver function tests, including AST, ALT, and bilirubin, before each infusion and consider weekly monitoring if grade 1 LFT elevations occur. A liver biopsy may be considered if the patient is steroid-refractory or if there is concern for other differential diagnoses that would alter medical management.
Additional Considerations
In patients with isolated elevation of alkaline phosphatase (ALP), GGT should be tested to determine if the elevation is of hepatic or nonhepatic origin, as recommended by 1. For isolated elevation of transaminases, considering checking CK for other etiologies is crucial. The management of elevated GGT levels should prioritize the identification and treatment of the underlying cause to improve patient outcomes and reduce the risk of morbidity and mortality.
From the Research
Causes of Elevated GGT
Elevated Gamma-Glutamyl Transferase (GGT) levels can be caused by various factors, including:
- Liver dysfunction and disease, such as alcoholic liver disease, which is associated with increased GGT activities in serum and liver 2
- Alcohol consumption, as chronic alcohol consumption leads to increased activities of GGT in the serum 2
- Cardiovascular events and mortality, as elevated serum GGT activity is associated with increased risk of mortality and major vascular outcomes 3
- Type 2 diabetes, chronic kidney disease, and cancer, as elevated GGT levels are associated with an increased risk of these conditions 3
- Cardiometabolic risk factors, such as diabetes, high waist circumference, and hypertension, which are associated with significant liver fibrosis among individuals with increased alcohol use 4
Association with Liver Disease
The association between elevated GGT levels and liver disease is well-established, with studies showing that statin use may reduce the risk of cirrhosis and related complications in patients with chronic liver diseases 5, 6
- Statin use has been shown to be associated with a lower risk of hepatic decompensation and mortality in patients with cirrhosis 6
- However, the evidence for the association between statin use and risk of development of cirrhosis or fibrosis progression in patients with chronic liver disease without cirrhosis is very low-quality 6
Other Factors
Other factors that may contribute to elevated GGT levels include: