Acromegaly

Question 1

Acromegaly is the clinical manifestation of what?

Answer 1

Excessive GH release

Question 2

What is the commonest cause of acromegaly?

Answer 2

Pituitary adenoma resulting in unregulated GH secretion

Question 3

Name 3 features of excessive GH secretion

Answer 3

• Prominent forehead and brow
• Large nose
• Large tongue (“macroglossia”)
• Large hands and feet
• Large protruding jaw (”prognathism”)
• Arthritis from imbalanced growth of joints
• Excessive sweating

Question 4

Name 2 physiological dysfunctions that can be caused by acromegaly

Answer 4

• Hypertension
• Type 2 diabetes
• Colorectal cancer
• Hypertrophic heart

Question 5

1) What is the initial screening test for acromegaly?
2) If this is raised, what would be the next test conducted?
3) What result of this test would imply acromegaly, and why?

Answer 5

1) Insulin-like Growth Factor 1 (IGF-1)
2) Oral glucose tolerance test whilst measuring growth hormone
3) Persistent high GH as high glucose normally suppresses growth hormone

Question 6

What is the definitive treatment of acromegaly secondary to pituitary adenomas?

Answer 6

Trans-sphenoidal removal of the tumour

Question 7

Medication for acromegaly
1) How does pegvisomant work?
2) How do somatostatin analogues work?
3) Normally, somatostatin is secreted by which 3 organs?
4) What other group of drugs, and name an example, can be used for the medical management of acromegaly?

Answer 7

1) GH antagonist
2) Somatostatin is a growth hormone inhibiting hormone, therefore somatostatin analogues inhibits GH
3) Pancreas, brain and GI tract
4) Dopamine antagonists i.e. bromocriptine