Acromegaly

 

• Pathophysiology

  • Pituitary adenoma secreting growth hormone (GH), which acts on liver to release insulin-like growth factor 1 (IGF-1).
  • These hormones cause a range of metabolic and connective tissue changes.
  • PRL co-secretion in 25%.

• Signs and symptoms

  Soft tissue overgrowth, especially in hands, feet, and face:

  • Coarse face.
  • Carpal tunnel syndrome.
  • Snoring
  • Joint pain.
  • Gigantism results from untreated, pre-pubertal acromegaly.

  Other features:

  • Hypogonadism if there is PRL co-secretion.
  • Organomegaly
  • Fatigue
  • Headache
  • Osteoarthritis
  • CV: HTN, arrhythmia, LVH/cardiomyopathy.
  • Metabolic: ↑appetite, ↑glucose leading to polydipsia+uria (GH causes ↑gluconeogenesis and ↑lipolysis).

• Investigations

  • ↑GH, ↑IGF-1 (according to sex and age-specific normal ranges).
  • Oral glucose tolerance test: glucose fails to sufficiently suppress GH.

• Management

  Transsphenoidal surgical excision is 1st line.

  Other options, either as alternatives or adjuncts to surgery:

  • Radiotherapy
  • Medication: somatostatin analogues (octreotide), dopamine agonists (cabergoline, bromocriptine).