From the Guidelines
A slightly elevated GGT level is a common laboratory liver abnormality, present in >85% of adult Fontan patients, and indicates mild liver stress but isn't usually cause for immediate concern. To address this, it's essential to focus on lifestyle modifications, as high GGT levels independently predict clinical outcomes on multivariate analysis 1. Reducing or eliminating alcohol consumption is crucial, as it's a common cause of elevated GGT. A liver-healthy diet with plenty of fruits, vegetables, whole grains, and lean proteins, while avoiding processed foods, excessive sugar, and saturated fats, is recommended. Staying well-hydrated with water and maintaining a healthy weight through regular exercise are also vital. If medications are being taken, discussing them with a doctor is necessary, as some can affect liver enzymes.
Some key points to consider:
- GGT is an enzyme found primarily in the liver and bile ducts, and its elevation can result from alcohol use, certain medications, fatty liver disease, or other conditions affecting the biliary system 1.
- The liver has remarkable regenerative abilities, and lifestyle changes often normalize GGT levels within 2-3 months.
- If GGT remains elevated despite lifestyle changes or if other concerning symptoms are present, follow-up with a healthcare provider for further evaluation is necessary.
- In patients with Fontan-type circulation, a mild increase in serum gamma-glutamyltransferase is the most common and early laboratory liver abnormality, and markers of cholestasis are not clearly associated with worse cardiac function, more severe liver fibrosis, or impairment of other liver function parameters 1.
- High GGT levels have been associated with an aggressive course of chronic viral hepatitis, and with an increased rate of clinical decompensation events and HCC in patients with cirrhosis, emphasizing the importance of lifestyle modifications to limit liver disease progression 1.
From the Research
Slightly High GGT Levels
- A slightly high GGT (gamma-glutamyl transferase) level may be associated with an increased risk of developing fatty liver disease, as shown in a retrospective cohort study 2.
- Elevated GGT levels are also linked to the metabolic syndrome and may be a prognostic marker for cardiovascular disease, including cardiovascular mortality, atrial fibrillation, and congestive heart failure 3.
Associated Risk Factors
- High triglyceride (TG) levels are an independent predictor of fatty liver changes in individuals with elevated GGT levels 2.
- Other risk factors associated with fatty liver changes in individuals with normal GGT levels include body mass index (BMI), hemoglobin, alanine aminotransferase (ALT), albumin, and high-density lipoprotein levels 2.
Management of Hypertriglyceridemia
- Omega-3 fatty acids, particularly EPA and DHA, have been shown to be effective in reducing triglyceride levels and may be used as monotherapy or in combination with other lipid-lowering agents 4.
- Co-supplementation of vitamin E and omega-3 fatty acids may also be beneficial in reducing VLDL levels, although its effect on other lipid profile parameters requires further study 5.
Dietary Recommendations
- Limiting intake of saturated fatty acids (SFA) to less than 10% of total daily energy is recommended for the general healthy population, and further reduction to 5-6% of total daily energy may be beneficial for patients with hypercholesterolemia 6.
- Replacing SFA with unsaturated fatty acids, particularly polyunsaturated fatty acids, may help reduce the risk of atherosclerotic cardiovascular disease (ASCVD) 6.