What is the characteristic pattern of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma‑glutamyltransferase (GGT) and alkaline phosphatase (ALP) levels in heavy alcohol users, and what is the first‑line management for alcoholic liver injury?

Characteristic Liver Enzyme Pattern in Heavy Alcohol Users

In heavy alcohol users, the characteristic pattern shows AST > ALT with an AST/ALT ratio typically exceeding 2:1, elevated GGT (the most sensitive marker detecting 75% of habitual drinkers), and both AST and ALT levels rarely exceeding 300 IU/L, while ALP remains normal or mildly elevated. 1, 2, 3

Specific Enzyme Patterns

AST and ALT Relationship

• The AST/ALT ratio greater than 2:1 is highly suggestive of alcoholic liver disease, particularly alcoholic hepatitis, with ratios exceeding 3 being even more specific for alcohol-related injury 1, 3, 4
• An AST/ALT ratio of 1.22 suggests early alcoholic liver injury, though ratios >1.5-2.0 provide greater specificity for alcohol-related disease 2, 4
• Both transaminases typically remain below 300 IU/L; levels exceeding this threshold should prompt investigation for alternative or additional causes of liver injury 2, 3
• AST elevation predominates over ALT because alcohol causes mitochondrial damage, leading to greater AST release 3
• In about 70% of patients with alcoholic liver disease, the AST/ALT ratio exceeds 2 3

Critical Pitfall with Transaminases

• More than 50% of patients with advanced fibrosis from alcohol have normal or minimally elevated transaminases, making AST and ALT levels potentially misleading for detecting significant liver disease 2
• Normal transaminases do not exclude advanced alcohol-related liver disease and should not provide false reassurance 2, 5

Gamma-Glutamyl Transferase (GGT)

• GGT is elevated in approximately 75% of habitual drinkers, making it the most sensitive single marker for chronic alcohol consumption 2, 3, 4
• GGT elevation results from enzyme induction by chronic alcohol consumption rather than solely from liver cell injury 3, 6
• GGT levels recover slowly over months following abstinence, making it useful for monitoring compliance with alcohol cessation 2
• The ratio of GGT to alkaline phosphatase exceeding 1.4 has 78% specificity for alcoholic liver injury 4

Alkaline Phosphatase (ALP)

• ALP remains normal or only mildly elevated in most cases of alcoholic liver disease 7
• ALP elevation becomes more prominent in cholestatic patterns or advanced cirrhosis 1

First-Line Management for Alcoholic Liver Injury

Absolute Priority: Alcohol Abstinence

Alcohol abstinence is the single most important determinant of long-term outcomes and must be the cornerstone of all management strategies. 2, 5

Structured Intervention Approach

• Implement motivational interviewing using the "5 As" model (Ask, Advise, Assess, Assist, Arrange) with empathic, non-judgmental communication 2, 5
• Calculate precise alcohol consumption using the formula: (volume in mL × alcohol % × 0.785) ÷ 100 to determine grams of alcohol consumed daily 2
• Administer the AUDIT questionnaire, with scores >19 indicating alcohol dependence requiring referral to addiction services 2
• Present objective feedback linking specific alcohol consumption to liver enzyme elevation and long-term cirrhosis risk 2, 5

Pharmacotherapy for Alcohol Use Disorder

• Consider prescribing naltrexone, acamprosate, or disulfiram for patients with alcohol use disorder to support abstinence 2, 5

Essential Diagnostic Workup

• Order GGT and arrange urgent non-invasive fibrosis assessment (FibroScan or FibroTest) to assess for advanced alcohol-related liver disease, as current laboratory findings may not exclude this condition 2
• Obtain complete metabolic panel including albumin, bilirubin, INR, and platelet count to assess synthetic liver function 2
• If FibroScan >12-15 kPa, this suggests advanced fibrosis; if >16 kPa, refer to hepatology for advanced liver disease management 2

Nutritional Support

• Prescribe high-protein diet (1.2-1.5 g/kg/day) with adequate caloric intake (30-35 kcal/kg/day) 5
• Supplement with B vitamins (thiamine, folate, B12) and folic acid 5

Surveillance for Advanced Disease

• If FibroScan reveals significant fibrosis (F3-F4), initiate cirrhosis surveillance protocols including upper endoscopy for variceal screening and hepatocellular carcinoma surveillance with ultrasound ± AFP every 6 months 2, 5
• Recheck AST, ALT, GGT, albumin, bilirubin, INR, and platelet count in 2-4 weeks if the patient achieves abstinence 2

Role of Liver Biopsy

• Liver biopsy is not necessary for routine diagnosis or treatment 1
• For patients with severe alcoholic hepatitis who may require corticosteroid treatment, liver biopsy should be considered for definitive diagnosis and prognosis determination 1