Evaluation of Elevated Liver Enzymes

Initial Assessment and Risk Factors

The American College of Gastroenterology recommends beginning with a complete liver panel, viral hepatitis serologies, and abdominal ultrasound to identify common causes of elevated liver enzymes, such as nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease, viral hepatitis, and medication-induced liver injury 1
Obtaining a detailed alcohol consumption history is crucial, as alcoholic liver disease is a common cause of elevated ALT, with consumption ≥14-21 drinks/week in men or ≥7-14 drinks/week in women suggesting alcoholic liver disease 2, 1
Assessing for metabolic syndrome components, including waist circumference measurement, blood pressure, obesity, diabetes, and hypertension, is essential, as these are critical risk factors for NAFLD, which affects 20-30% of the general population and up to 70% of obese individuals 1, 3

The American Association for the Study of Liver Diseases recommends ordering a complete liver panel, including AST, ALT, alkaline phosphatase, GGT, total and direct bilirubin, albumin, and prothrombin time/INR, to evaluate liver function 1
Calculating the AST/ALT ratio provides diagnostic clues, with a ratio >2 suggesting alcoholic liver disease, and a ratio <1 characteristic of NAFLD, viral hepatitis, or medication-induced liver injury 2, 1

For patients with suspected NAFLD, calculating the FIB-4 score using age, ALT, AST, and platelet count can assess the risk of advanced fibrosis, with a score >2.67 indicating high risk 1
Implementing lifestyle modifications, such as a low-carbohydrate, low-fructose diet, and 150-300 minutes of moderate-intensity aerobic exercise weekly, can help manage NAFLD 1
For patients with suspected alcoholic liver disease, complete alcohol abstinence is strongly recommended, and monitoring for alcoholic hepatitis is essential if AST is typically 2-6 times ULN with an AST/ALT ratio >2 1

Referring patients to hepatology is recommended if liver enzymes remain elevated for ≥6 months without an identified cause, or if there is evidence of synthetic dysfunction, such as decreased albumin or prolonged prothrombin time 1, 2
The American College of Gastroenterology recommends liver biopsy in patients with unclear diagnosis after non-invasive evaluation, or in those with suspicion of autoimmune hepatitis or advanced fibrosis 1