Anorexia Nervosa: Cellular Starvation and Multi-Organ Consequences

Anorexia at the Cellular Level

Severe caloric restriction forces cells into catabolic survival mode, disrupting fundamental processes.

Cellular & Molecular Effects

• Energy Crisis: ↓ ATP → Na⁺/K⁺-ATPase failure → cellular edema, membrane instability.
• Protein Sparing Failure: Autophagy and ubiquitin-proteasome degradation of structural/functional proteins → muscle wasting, enzyme loss.
• Mitochondrial Dysfunction: Reduced biogenesis, increased ROS, apoptosis.
• Hormonal Reprogramming: Low leptin, insulin, T3, sex steroids; high cortisol, GH resistance → conserve energy, suppress reproduction.
• Electrolyte Chaos: Refeeding syndrome (hypophosphatemia, hypokalemia, hypomagnesemia) upon reintroduction of carbs.
• Immune Suppression: Lymphopenia, thymic atrophy → infection risk.

Organ-System Manifestations

• Heart: Atrophy, arrhythmias, mitral valve prolapse, sudden death.
• Brain: Gray/white matter loss, cognitive impairment, seizures.
• Bone: Osteoporosis (↓ osteoblasts, ↑ osteoclasts, low estrogen/IGF-1).
• GI: Gastroparesis, superior mesenteric artery syndrome.
• Renal: Stones, nephrocalcinosis, impaired concentration.

Recovery

Requires careful, supervised nutritional rehabilitation to avoid refeeding syndrome; full cellular recovery takes months to years.