How can you determine if anorexia nervosa has affected the liver?

Detecting Liver Involvement in Anorexia Nervosa

Liver function tests should be routinely performed in all patients with anorexia nervosa, as liver dysfunction is common and can be severe, with up to 35.4% of patients showing significantly elevated liver enzymes. 1

Laboratory Assessment

The American Psychiatric Association (APA) provides clear guidelines for evaluating patients with eating disorders:

• Required laboratory tests:
  • Complete blood count
  • Comprehensive metabolic panel including:
    • Electrolytes
    • Liver enzymes (AST, ALT)
    • Renal function tests 2

Clinical Signs of Liver Involvement

Liver dysfunction in anorexia nervosa typically presents with:

1. Elevated liver enzymes:

   • Mild elevation (up to 3× upper limit of normal) in 27.6% of patients
   • Severe elevation (>3× upper limit of normal) in 35.4% of patients 1

2. Risk factors for severe liver dysfunction:

   • Lower BMI (<12 kg/m²)
   • Lower percentage of ideal body weight (<57%)
   • Low prealbumin levels 1

3. Associated clinical findings:

   • Hypoglycemia
   • Hypophosphatemia
   • Longer hospitalization requirements 1

Mechanisms of Liver Damage in Anorexia

Several mechanisms contribute to liver dysfunction in anorexia nervosa:

1. Hepatic hypoperfusion: Severe malnutrition leads to:

   • Marked hypotension
   • Bradycardia
   • Reduced cardiac output
   • Resulting in ischemic hepatitis 3, 4

2. Starvation-induced autophagy: Prolonged malnutrition causes:

   • Excessive glycogen deposition in liver cells
   • Hepatocyte death due to prolonged starvation 5

3. Refeeding complications: Rapid nutritional rehabilitation can cause:

   • Metabolic shifts
   • Further elevation of liver enzymes during early refeeding 5

Differential Diagnosis

When evaluating liver dysfunction in anorexia nervosa, it's essential to exclude other causes:

• Viral hepatitis
• Drug-induced liver injury
• Alcohol-related liver disease
• Substance abuse (cannabis, cocaine)
• Autoimmune hepatitis 3

Monitoring and Management

For patients with anorexia nervosa showing liver dysfunction:

1. Initial assessment:

   • Monitor vital signs including orthostatic measurements
   • Assess hydration status
   • Check for signs of multiorgan dysfunction 2

2. Treatment approach:

   • Immediate plasma volume support for hypotension
   • Careful nutritional rehabilitation (gradual to avoid refeeding syndrome)
   • Parenteral potassium and phosphorus supplements as needed 3

3. Follow-up monitoring:

   • Serial liver function tests until normalization
   • Monitoring for hypoglycemia (common in severe cases)
   • Extended hospitalization may be required for severe cases 1, 6

Prognosis

With appropriate medical management, liver dysfunction in anorexia nervosa is typically reversible:

• Liver enzymes generally normalize with proper hydration and nutritional support
• Complete recovery of liver function can occur within days to weeks 3, 6
• Recurrent episodes of liver dysfunction may occur with relapse of severe malnutrition 4

Common Pitfalls

1. Misdiagnosis: Attributing liver dysfunction to other causes without considering the impact of severe malnutrition
2. Inadequate monitoring: Failing to perform liver function tests in anorexia patients
3. Overly aggressive refeeding: Can worsen liver dysfunction through refeeding syndrome
4. Underestimating severity: Liver dysfunction can progress to acute liver failure in severe cases

Liver dysfunction is a serious but often overlooked complication of anorexia nervosa that requires prompt recognition and appropriate management to prevent progression to liver failure.