Acromegaly

Question 1

Definition

Answer 1

Excessive production of growth hormone = adults after fusion of epiphyseal plates
Called gigantism in children

Question 2

Epidemiology

Answer 2

Males = Females
Diagnosis = 40 years old

Question 3

Risk Factors

Answer 3

GPR101 over expression
MEN1 syndrome
- Pituitary adenoma
- Pituitary hyperparathyroidism
- Pancreatic neuroendocrine tumours

Question 4

Aetiology

Answer 4

Functional Pituitary Adenoma (90%)
Ectopic release of GH (neuroendocrine tumour)
Ectopic release of GHRH: carcinoid tumour or SCLC
Excess hypothalamic release of GHRH: hypothalamic tumour

Question 5

Pathophysiology

Answer 5

GHRH -> GH -> travels to tissues such as liver where it binds to receptors resulting in increase in IGF-1
This stimulates skeletal and soft tissue growth.
Local tumour expansion of the pituitary can result in compression of surround structures = headaches + visual field loss

Question 6

Signs

Answer 6

Large hands
Box jaw
Thick skin
Bitemporal hemianopia
HTN
Insulin resistance -> T2DM
Organomegaly
Large interdental gaps + macroglossia
Carpel Tunnel syndrome

Question 7

Symptoms

Answer 7

Headaches
Arthritis
Sight problems
Obstructive sleep apnoea
Polyuria + Polydipsia (secondary to T2DM)
Arthralgia/Backpain

Question 8

Diagnosis

Answer 8

FIRST LINE: Serum insulin like growth factor 1 (IGF-1) elevated
GOLD STANDARD: Oral glucose tolerance test - confirmational after IGF-1
Random serum growth hormone
MRI of head

Question 9

Treatment

Answer 9

FIRST LINE: Transsphenoidal surgery
SECOND LINE: Somatostatin analogue (OCTEOTRIDE)
THIRD LINE: GH receptor antagonist (PEGVISOMANT)
FOUTH LINE: Dopamine agonist (CARBERGOLINE OR BROMOCRIPTINE)

Question 10

Complications

Answer 10

T2DM
Sleep Apnoea