What does elevated Gamma-Glutamyl Transferase (GGT) indicate in the context of purging behaviors?

Elevated GGT in the Context of Purging Behaviors

Elevated Gamma-Glutamyl Transferase (GGT) in patients with purging behaviors is not specific to the eating disorder itself but may indicate liver damage that can be caused by multiple factors including malnutrition, medication use, or alcohol consumption that may coexist with the eating disorder. 1, 2

Understanding GGT Elevation in Purging Behaviors

• GGT elevation is relatively uncommon in eating disorder patients, occurring in approximately 4.1% of outpatients with eating disorders 1
• In patients with purging behaviors, elevated GGT may be related to:
  • Low body weight and malnutrition (correlates with lower current and past weight/BMI) 1
  • Alcohol use, which is the most common cause of elevated GGT (present in about 75% of habitual drinkers) 2, 3
  • Medication use that may accompany eating disorders (antipsychotics, estrogens, etc.) 3

Clinical Significance and Interpretation

• GGT elevation should be interpreted in context with other liver enzymes, not in isolation 2, 3
• Calculate AST:ALT ratio - a ratio >1 may indicate advanced fibrosis/cirrhosis 2
• When elevated with purging behaviors, consider:
  • Potential alcohol misuse (which may be comorbid with eating disorders) 4, 3
  • Medication-induced liver injury 3, 5
  • Malnutrition-related liver damage 1

Diagnostic Approach for Elevated GGT in Purging Patients

• Determine if GGT elevation is isolated or accompanied by other liver enzyme abnormalities 2
• Assess for alcohol consumption using standardized tools like AUDIT questionnaire 4, 2
• Evaluate medication history for potential hepatotoxic drugs 3, 5
• Consider additional laboratory workup:
  • Complete liver panel (bilirubin, albumin, ALT, ALP) 2
  • Viral hepatitis testing (HBsAg, HCV antibody) 2
  • Iron studies and autoimmune markers 2

Imaging and Further Evaluation

• Abdominal ultrasonography should be the first-line imaging modality to evaluate liver parenchyma and biliary tree 2
• If ultrasound is inconclusive and cholestatic pattern is present, consider magnetic resonance cholangiopancreatography (MRCP) 2

Management Recommendations

• Address the underlying eating disorder and purging behaviors through appropriate psychiatric/psychological interventions
• If alcohol use is identified, recommend complete abstinence as GGT levels recover slowly following cessation 2, 3
• Monitor GGT levels every 2-4 weeks initially to establish trend (increasing, stable, or decreasing) 2
• Refer to hepatology/gastroenterology if:
  • GGT elevation persists >3 months despite addressing modifiable factors 2
  • Evidence of advanced fibrosis or cirrhosis is present 2
  • Imaging studies suggest structural liver or biliary disease 2

Important Caveats

• GGT elevation alone has low specificity and should not be attributed solely to the eating disorder 3, 1
• Avoid attributing elevated GGT solely to alcohol without proper investigation of other causes 2, 3
• Be aware that both AST and ALT can be normal even in the setting of cirrhosis 2
• GGT elevation may also be associated with cardiovascular risk and metabolic syndrome, which should be considered in the overall patient assessment 6, 7