Acromegaly

Question 1

Investigations in acromegaly

Answer 1

Insulin like growth factor (IGF-I)
- unlike GH, which is affected by exercise & diet, IGF-I does not fluctuate
Diagnosis confirmed with GTT
- GH suppression is measured in response to a glucose load
- Failure of suppression is characteristic of acromegaly but the test is non-specific
Prolactin level elevated in 25%, can be associated with galactorrhoea
Test other pituitary hormones - prolactin, 9am cortisol, TSH, T4, FSH & LH, testosterone or oestradiol
MRI once elevated IGF I is confirmed

Question 2

Complications of acromegaly

Answer 2

Increased risk of cardiovascular disease
- HTN
- LV dilatation (+/- CCF)
- cardiomyopathy 
- arrhythmia 
- IHD & stroke
Increase in incidence of colonic polyps & carcinoma of the colon
Associated with OSA
Impaired glucose tolerance

Question 3

Screening for complications in acromegaly

Answer 3

1. Cardiovascular: echo 5 to 10 yearly (CCF, valve failure)
2. GI - colonoscopy at diagnosis & surveillance
3. Thyroid
4. Metabolic: BP, lipids, fasting BSL annually
5. MSK: symptoms, carpal tunnel, arthropathy