Acromegaly

Question 1

What is acromegaly?

Answer 1

A multi-systemic and progressive condition caused by excessive secretion of growth hormone (GH)

Question 2

What is the aetiology of acromegaly?

Answer 2

Most common cause it pituitary somatotrohp adenoma (95-99%) of cases
rarely because of ectopic secretion from neuroendocrine tumours

Question 3

What is the function of IGF-1

Answer 3

Increases skeletal growth

Increases muscle growth

Question 4

What is the role of GH

Answer 4

• Acts on the liver in order to stimulate the production of IGF-1
• Also causes the breakdown of fat and glycogen to glucose causing an increase of glucose. (stores in the liver)

Question 5

What inhibits growth hormone secretion?

Answer 5

Somatostatin and Growth hormone

Question 6

What are the symptoms of Acromegaly?

Answer 6

Visual disturbance - bitemporal hemianopia 
Headaches 
Rings and shoes are tight 
Tingling in hands (carpel tunnel) 
polyuria/polydipsia (T2DM)

Question 7

What are the signs of acromegaly?

Answer 7

• bitemporal hemianopia
• facial features - prominent jaw and supra-orbital ridge, prognathism, splaying of teeth, macroglossia
• spade like hands
• deep husky voice
• sweaty palms
• hypertension

Question 8

What are the differentials of acromegaly?

Answer 8

Gigantism vs acromegaly

Question 9

Acromegaly vs gigantism

Answer 9

Acromegaly occurs after your growth plates are fused therefore the height isn’t affected, where as gigantism happens before fusion (childhood) therefore they have a height greater than their age.
Acromegaly doesn’t affect puberty but in gigantism happens before and the pituitary adenoma will alter hormones therefore you will have delayed puberty

Both caused by excessive growth hormone.

Question 10

What are the investigations for acromegaly?

Answer 10

Bedsides:
- ECG: acromegaly can cause cardiomyopathy and heart failure.

Bloods:

• IGF1: 1st line and riased
• OGTT: a glucose load should cause suppression of GH normally. in acromegaly there is failure of suppression

Imaging

• Pituitary MRI: Visalisation of pit adenoma
• CT ches, abdo and pelvis: very rarely can be due to an ectopic source

Special tests:
- visual field testing.

Question 11

What is the management of acromegaly?

Answer 11

First line:
- Surgery - trans-sphenoidal resection of the pituitary

Second line:

• medical: dopamine agonists (e.g. cabergoline) in mild disease and somatostatin analogues (e.g. octreotide) in severe disease.
• Pegvisomant is a GH antagonist which is sometimes used, although expensive

Third line:
- radiotherapy: reserved for patients who are refractory to medical and surgical treatment.

Question 12

What are the complications?

Answer 12

Cardiac:
- cardiomyopathy, hypertension, heart failure

Respiratory: obstructive sleep apnoea

Neurological: carpal tunnel syndrome, proximal myopathy

Endocrine: T2DM, panhypopituitarism

Gastro: colorectal cancer.