Acromegaly

Question 1

What causes acromegaly?

Answer 1

• excess growth hormone
• > 95% from pituitary adenoma
• 5% ectopic GHRH or GH production by tumours e.g. pancreatic

Question 2

Features of acromegaly

Answer 2

coarse facial appearance
spade-like hands
increased shoe size
large tongue
large interdental spaces
excessive sweating and oily skin: (sweat gland hypertrophy)

Features of pituitary tumour: hypopituitarism
headaches
bitemporal hemianopia
raised prolactin in 1/3 of cases → galactorrhoea

Question 3

Name some complications of acromegaly

Answer 3

Hypertension
diabetes (>10%)
cardiomyopathy
colorectal cancer

Question 4

Why are growth hormone levels NOT used to diagnose acromegaly?

Answer 4

Growth hormone (GH) levels vary during the day

Question 5

Serum IGF-1 may also be used to monitor disease. TRUE/FALSE?

Answer 5

TRUE

Answer 6

Oral glucose tolerance test
in normal patients GH is suppressed to < 2 mu/L with hyperglycaemia
in acromegaly there is no suppression of GH
may also demonstrate impaired glucose tolerance which is associated with acromegaly

Question 7

What investigations are used to confirm a diagnosis of acromegaly?

Answer 7

1) Raised Serum IGF-1 levels
THEN
2) serial GH levels with OGTT
(in normal paitents, growth hormone is suppressed with hyperglcyaemia)

May also demonstrate pituitary adenoma on MRI

Question 8

What is the first line treatment of acromegaly in the majority of patients

Answer 8

Trans-sphenoidal surgery

Question 9

What medication can be used to treat acromegaly if surgery is not an option

Answer 9

1) somatostatin analogue - inhibits release of growth hormone (e.g. OCTREOTIDE)
octreotide

2) pegvisomant -
- GH receptor antagonist
- once daily s/c administration
- decreases IGF-1 levels
- doesn’t reduce tumour volume

3) dopamine agonists
- e.g. bromocriptine

4) External irradiation if failed medical/surgical Tx