Acromegaly

Question 1

What is acromegaly?

Answer 1

Excessive growth of the extremeties due to increased secretion of growth hormone, usually from a pituitary tumour. (OHCM, lecture 16.4.18)

Question 2

Describe the pathogenesis of acromegaly.

Answer 2

A pituitary tumour causes the anterior pituitary gland to produce excess GH, which causes the liver to produce IGF-1. Most are macroadenomas (>1cm) which grow more than microadenomas (<1cm)

Question 3

Give 5 symptoms of acromegaly.

Answer 3

1. Excessive sweating (48%)
2. Arthralgias (42%)
3. Acroparasthaesia: tingling/numbness in the extremities.
4. Hypogonadal symptoms (39%): Amenorrhoea, decreased libido
5. Headache (38%)
   Snoring
   Backache
   (lecture, OHCM)

Question 4

Give 5 signs of acromegaly

Answer 4

Signs often significantly predate diagnosis.
1. Acral enlargement (86%)
2. Maxillofacial changes (74%) - coarse face, wide nose
3. Big supraorbital ridges
4. Macroglossia
5. Widely spaced teeth
Puffy lips, eyelids and skin, skin tags, skin darkening, goitre due to increased thyroid vascularity, carpal tunnel signs
Insidious onset

Question 5

How is acromegaly diagnosed?

Answer 5

1. History and exam for symptoms and signs
2. Bloods: Increased glucose, calcium and phosphate.
3. Random GH and IGF-1.
   If random GH <0.4bg/ml and normal IGF-1, exclude acromegaly. If abnormal:
4. oral glucose tolerance test. Lowest GH value during OGTT is >1ng/L = acromegaly.

Question 6

Describe the management of acromegaly.

Answer 6

1. Pituitary surgery to remove tumour. Cure rate is much higher for microadenomas, but these are the minority. This reduced tumour compression and reduced GH and IGF-1.
2. Medical therapy to control GH and IGF-1 if surgery fails - GH receptor antagonists eg pegvisomant
   Somatostatin analogues eg octreotide
3. Radiotherapy

Question 7

What are the aims of acromegaly treatment?

Answer 7

Correct GH and IGF-1
 relieve symptoms
 reverse visual and soft-tissue changes
Prevent further skeletal deformity
 restore normal pituitary function.

Question 8

What can cause increased growth hormone?

Answer 8

Stress
Sleep
Puberty
Pregnancy
(OHCM)

Question 9

What age does acromegaly normal present at?

Answer 9

44 years at diagnosis, usually signs start 8 years prior.

Question 10

Give 3 complications of acromegaly

Answer 10

Hypertension, LV hypertrophy, cardiomyopathy, arrythmias.
Impaired glucose tolerance and type 2 diabetes
Increased risk of colon cancer
Liver enlargement

Question 11

What has happened if a patient presents with gigantism?

Answer 11

GH hypersecretion occurred before puberty, before the bony epiphyses fused.