Acromegaly Flashcards
What is acromegaly?
Acromegaly is a hormonal disorder where the pituitary gland produces excessive amounts of growth hormone (GH) in the body after the growth plates have closed.
Usually the excess GH comes from benign, or noncancerous, tumors on the pituitary.
What is the main cause of acromegaly?
Pituitary adenoma
What are the other causes of acromegaly?
Pituitary tumour
Hyperplasia of pituitary gland
Ectopic Growth hormone releasing hormone from a carcinoid tumour
What inhibits GH?
Somatostatin
What does GH do?
Stimulate soft tissue and skeletal growth through increased secretion of insulin-like growth factor (IGF-1)
What are the symptoms of acromegaly?
Acroparasthesia Amenorrhoea Decreased libido Headache Increased sweating Snoring Arthralgia Backache
What are the signs of acromegaly?
- Increased growth of hands - spade like hands “my rings don’t fit”
- Increased feet size - “ my shoes don’t fit”
- Coarsening face & facial features, wide nose
- Big supraorbital ridges
- Macroglossia
- Widely spaced teeth
- Puffy lips, lids and skin
- Skin tags
- Scalp folds
- Skin darkening
- Acanthosis nigricans
- Laryngeal dyspnoea (fixed cords)
- Obstructive seep apnoea
- Goitre
What are some complications of acromegaly?
40% have impaired glucose tolerance
15% develop diabetes as a result
Vascular problems:
- Raised BP
- Left ventricular hypertrophy
- Cardiomyopathy
- Arrythmias
The raised BP and insulin resistance causes an increased risk of stroke and and ischaemic heart disease
Increased risk of colon cancer
How does acromegaly affect pregnancy?
Subfertility is common (may take a while to conceive)
But pregnancies may be normal, need to monitor glucose
When is GH secretion increased?
Stress
Pregnancy
Sleep
Puberty
How could you diagnose acromegaly?
Glucose is increased
Phospahte increased
Calcium increased
GH levels BUT not random - oral glucose tolerance test as normally glucose suppresses secretion of glucose but in acromegaly GH would still be high in presence of high glucose
In which conditions are GH secretions particularly high?
Hepatic and renal disease
Diabetes
Anorexia nervosa
If the patient has these conditions, it could lead to a false positive
What imaging investigations would you carry out to diagnose acromegaly?
MRI scan of pituitary fossa - look for hypopituitarism
ECG and Echo for signs of cardiomyopathy
How is acromegaly treated?
Transsphenoidal surgery to excise the lesion (if its caused by a pituitary tumour)
Somatostatin analogue - Octreotide IM or lantreatide
Pegvisomant - GH antagonist that;s used if patient is resistant or intolerant to SSA
Radiotherapy if unsuitable for surgery (it may take years to work)
What are the side effects of octreotide?
Pain at the injection site GI disturbances Abdominal cramps Flatulence Loose stools Increase gallstones Impaired glucose tolerance (diabetes)
