Acromegaly

Question 1

Define Acromegaly

Answer 1

Chronic, progressive, multi-systemic disease caused by excessive Growth Hormone (GH) secretion

Question 2

Aetiology of Acromegaly

Answer 2

Pituitary somatotroph adenoma (95-99%)

Somatotroph hyperplasia with neuroendocrine tumours (hypothalamic or digestive) that produces GHRH

Question 3

Risk factors for Acromegaly

Answer 3

GPR101 over-expression
Multiple endocrine neoplasia type 1 syndrome 
Isolated familial acromegaly 
McCune-Albright's syndrome
Carney's complex

Question 4

Symptoms of Acromegaly

Answer 4

Excessive sweating (hyperhidrosis)
Headache
Enlargement of supraorbital ridges, nose, hands and feet, thickening of lips and general coarseness of features 
Enlarged tongue 
Lower jaw protrusion (prognathism)
Carpal tunnel syndrome
Snoring
Fatigue 
Hypertension, arrhythmias
Visual field defects
Hypogonadism (due to high prolactin): reduced libido, amenorrhoea

Question 5

Signs of Acromegaly on examination

Answer 5

Excessive tissue growth: bone, cartilage, fibrous tissue, connective tissue, organs -> organomegaly
Barrel chest, kyphosis
Splayed-like hands/fingers
Frontal bossing
Macroglossia
Broad nose
Lower jaw protrusion due to mandible growth

Question 6

Investigations for Acromegaly

Answer 6

Oral glucose tolerance test: failed GH suppression (paradoxical rise) following an oral glucose load
IGF-1: elevated

Serum glucose, calcium, phosphate: elevated

ECG and echo: may show cardiomyopathy
MRI pituitary fossa: may show enlarged pituitary gland/tumour

Visual field and acuity assessment: may show bitemporal hemianopia

Question 7

Management for Acromegaly

Answer 7

Trans-sphenoidal surgery first line

+ stomatostatin analogues e.g. ocreotide (short acting or monthly depot injection)
+ Dopamine agonists e.g. cabergoline
+ radiotherapy

Yearly: assess GH, IGF-1, OGTT, visual assessment, BMI

Question 8

Complications of Acromegaly

Answer 8

Obstructive sleep apnoea 
Hypertension
Cardiomyopathies 
Increased risk of cancer 
Diabetes Mellitus / impaired glucose tolerance

Question 9

Prognosis for Acromegaly

Answer 9

Associated with serious complications and premature death
Better prognosis due to treatment advancement
Death from: cardiovascular disease, respiratory complications, cancer