From the Guidelines
Elevated GGT and ALT in an asymptomatic male adult necessitate a comprehensive liver aetiology screen, including abdominal ultrasound scan, hepatitis B and C screening, and autoantibody panel, as recommended by the 2018 guidelines on the management of abnormal liver blood tests 1. The initial investigation should include bilirubin, albumin, ALT, alkaline phosphatase, and GGT, along with a full blood count if not already performed within the previous 12 months, as outlined in Recommendation 1 of the guidelines 1. Key considerations in the interpretation of abnormal liver blood test results include:
- Review of previous results, past medical history, and current medical condition, as emphasized in Recommendation 2 1
- The extent of liver blood test abnormality not necessarily being a guide to clinical significance, as stated in Recommendation 3 1
- The importance of considering investigation with a liver aetiology screen irrespective of the level and duration of abnormality, as recommended in Recommendation 4 1 Further evaluation may involve risk stratification to determine the extent of liver fibrosis using either fibrosis-4 (FIB-4) or NAFLD Fibrosis Score (NFS) in adults with non-alcoholic fatty liver disease (NAFLD), as suggested in Recommendation 7 1. It is crucial to approach each case individually, taking into account the specific analyte that is abnormal and the clinical context, to determine the appropriate course of action and ensure the best possible outcome in terms of morbidity, mortality, and quality of life.
From the Research
Elevated GGT and ALT in Adult Males
Elevated gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT) levels in adult males can be indicative of various liver conditions. The following points summarize the key findings related to elevated GGT and ALT:
- Elevated liver enzymes, including GGT and ALT, are associated with increased liver disease mortality 2.
- Severe hepatic steatosis on ultrasound is also linked to higher liver disease mortality, but not independently associated with mortality from all causes, cardiovascular disease, cancer, or diabetes 2.
- The degrees of hepatic steatosis, as measured by ultrasound, are associated with the values of liver enzymes, including ALT, aspartate aminotransferase (AST), and GGT, as well as the homeostasis model assessment-insulin resistance (HOMA-IR) index 3.
- In patients with nonalcoholic fatty liver disease (NAFLD), elevated ANA titers and risk factors for NAFLD require a liver biopsy to make a definitive diagnosis of autoimmune hepatitis (AIH) 4.
- Patients with AIH and NAFLD overlap have unique characteristics, are less likely to receive standard of care treatment, but do not show significant differences in outcomes compared to patients with AIH or NAFLD alone 5.
- Autoantibodies, including ANA and anti-smooth muscle antibodies (anti-SMA), are present in a significant proportion of patients with NAFLD, and their presence is associated with more severe histological damage 6.
Key Findings
Some key findings related to elevated GGT and ALT in adult males include:
- Elevated GGT is associated with increased overall mortality 2.
- Elevated ALT is associated with increased liver disease mortality 2.
- The presence of autoantibodies in patients with NAFLD is associated with more severe histological damage 6.
- Liver biopsy is required to rule out AIH in most NAFLD patients with positive autoantibodies 4, 6.