Endocrinology Home

Acromegaly

Clinical features
Symptoms
Increased sweating
Headaches
Tiredness and lethargy
Joint pains
Erectile dysfunction/amenorrhoea
Change in ring or shoe size

Signs
Facial appearance (compare with old photos)
Coarse features, frontal bossing, enlarged nose, prominent facial folds and wrinkling, large fleshy nose, prognathism, increased tooth separation and jaw malocclusion.
Deep voice
Tongue enlargement
Enlargement of hands and feet
Skin tags
Goitre

Effects of Tumour
Visual field defects
Hypopituitarism

Complications
Hypertension
Insulin resistance and impaired glucose tolerance /diabetes mellitus
Congestive cardiac failure
Ischaemic heart disease and cerebrovascular disease
Obstructive sleep apnoea
Carpal tunnel syndrome


Diagnostic Investigations:

Investigations at the time of referral to endocrine outpatients:

IGF-1: Almost invariably elevated in acromegaly

NB Random Growth hormone estimates are not useful in the diagnosis of Acromegaly

Baseline Pituitary function tests  

Further Investigations (to be arranged from Endocrine clinic):

Urinary catecholamines: If the patient is hypertensive
Glucose suppression test In acromegaly, there is failure to suppress GH to <2mU/l in response to a 75g oral glucose load. In contrast, the normal response is GH suppression to undetectable levels.
MRI pituitary fossa MRI usually demonstrates the tumour, and whether there is extrasellar extension either suprasellar or into the cavernous sinus
Visual Fields  


Follow Up

  1. IGF-1: normalisation of IGF-1 has also been shown to be associated with reduction of increased mortality to normal
  2. 5 point GH day curve: patients are monitored following treatment using a GH day curve, aiming for a mean of <5 mU/L over 5 points throughout the day as epidemiological data suggest that a mean GH <5 mU/L is associated with reduction in mortality to that of the normal population.
  3. Colonoscopy: Every 5 years in patients >50 years old with uncured Acromegaly as this subgroup of patients are at increased risk of colonic neoplasm

Follow up of Acromegaly - 5 Point GH Day Curve

Indications

Assessment of cure or adequacy of treatment in Acromegaly

Procedure

Non-fasting
Tablets: take all prescribed drugs including Octreotide at normal time

Measurements



1. Take blood for Growth Hormone and IGF-1 at 0900h. (red or gold top vial).
2. Take blood for Growth Hormone at 1100, 1300, 1500 and 1700h

Interpretation guidelines

Mean GH of <5mU/L indicates cure/ disease control