Acromegaly is a condition caused by excess growth hormone. Almost all cases are due to a pituitary tumour.

Classical features include:
  • Soft tissue growth (large hands, coarsening of features etc)
  • Hyperhydrosis
  • Headaches
  • Parasthesia
  • Hypertension
  • Impaired glucose tolerance/diabetes
  • Hoarse voice

MRCP smaller-print features include:
  • Colonic polyps
  • Proximal myopathy
  • Arthralgia
  • Raised triglycerides
  • Osteopenia
  • Cardiomegaly – up to 90% in long-term patients
  • OSA

Diagnosis is by the failure of GH to decrease to less than 1 microgram/l 2 hrs after an oral glucose challenge of 75g. False positives may occur in pregnancy, diabetics, renal/hepatic impairment, obesity or those on oestrogen therapy.

Serum IGF-1 is raised but this is only useful for screening.

  • Transphenoidal surgery – 50-70% cure
  • Octreotide = somatostatin analogue – 70% efficacy – causes gallstones in 30%...
  • Pegvisomant = competitive GH receptor antagonist – 80% effective
  • Radiotherapy – but takes up to 20 yrs(!) to work
  • Dopamine agonists – bromocriptine not believed to be effective; cabergoline works in less than 10%

Small print gem: IGF1 is the target hormone for GH and mediates most of GH’s growth-promoting actions. 80% of IGF1 is made in the liver.

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Secret collector of interesting anonymised ECGs. Fan of the Bath Photomarathon. Lover of cream teas. [Sarah Hudson] (Your Picture)