Acromegaly

Question 1

What is acromegaly?

Answer 1

↑ secretion of GH

Question 2

What are the cause?

Answer 2

Pituitary tumour (95%) 
Hyperplasia

Question 3

What is growth hormone also known as?

Answer 3

Somatotropin

Question 4

Explain the GH axis

Answer 4

Hypothalamus releases GHRH which stimulates anterior pituitary to release GH
GH stimulates liver to release IGF (insulin like growth factor 1) which stimulates bone + tissue growth

Question 5

What are the sx

Answer 5

1. Facial features - frontal bossing, big nose, jaw enlargement, prognathism, separation of teeth, macroglossia
2. Big hands + feet
3. XS sweating + oily skin
4. Features of pituitary tumour - hypopituitarism, headaches, bitemporal hemianopia
5. Carpal tunnel syndrome
6. Proximal weakness + arthropathy
7. OSA, galactorrhoea

Question 6

What are the complications?

Answer 6

HTN
DM
Cardiomyopathy
Colorectal cancer

Question 7

What tests would you do?

Answer 7

1. Serum insulin-like growth factor 1 (IGF-1) - elevated
2. Oral glucose tolerance test - lack of suppression of GH
3. Random serum GH - not v reliable as varies during the day
4. MRI pituitary fossa, look for hypopituitarism, visual fields + acuity, ECG, echo, old photos

Question 8

What is the treatment of acromegaly?

Answer 8

1. Trans-sphenoidal surgery
2. if fails - somatostatin analogues (octeotride) and/or radiotherapy
3. GH antagonist - pegvisomant