Acromegaly Flashcards
GH:
Where is it produced from?
It causes the production of IGF-1. Where is this released from?
What effect does IGF-1 have on the body?
What does IGF-1 stand for?
What is the most common cause of acromegaly?
When is GH at it’s highest normally?
What is it called when their is a raised GH in someone BEFORE adolescence?
Pituitary gland - usually due to secreting tumour
Liver
Causes growth of bone and soft tissue
Insulin like growth factor-1
Pituitary adenoma
Most during sleep
Gigantism
Gigantism results from the over-secretion of growth hormone prior to the onset of adolescence (specifically prior to the fusion of epiphyses). Excessive growth hormone production associated with gigantism is most commonly due to the presence of a pituitary tumour. This condition presents with features resulting from excessive growth, including: increased height (sometimes between 7 and 9ft), spade-like hands and feet, prominent forehead and jaw, coarsening of facial features, visual disturbances, as well as other features.
Acromegaly is most commonly mistaken for gigantism. This condition results from excessive secretion of growth hormone after adolescence.
Symptoms:
Where is soft tissue growth the greatest?
Read through signs of soft tissue growth
Hands, feet, face
Coarse face Carpal tunnel syndrome Snoring - obstructive sleep apnoea Joint pain Gigantism Increased interdental spacing Big tongue
Think about soft tissue growth causing all of these!!
Other features - just read through
What systemic disease do they have?
What type of visual field defect do they get?
What key thing could you ask about that might give you a clue?
Hypogonadism Organomegaly Fatigue Headache Osteoarthritis
CV - HTN, arrhythmia, LVH/cardiomyopathy
T2DM
Bi temporal hemianopia
They have been having to change their glove and shoe size into their adult life.
LOOK AT STORY ON CAPSULE OR WATCHA VIDEO AS YOU ARE MORE LIKELY TO REMEMBER IT.
Investigations:
Apart from measuring hormone levels, why is an OGTT done?
What imaging needs to be done to look for a pituitary adenoma?
High glucose usually causes GH suppression - but suppression doesn’t happen in acromegaly.
REMEMBER, ACROMEGALY CAN CAUSE T2DM.
Acromegaly is an uncommon secondary cause of diabetes. Excess GH: 1) stimulates gluconeogenesis and lipolysis, causing hyperglycemia and elevated free fatty acid levels; 2) leads to both hepatic and peripheral insulin resistance, with compensatory hyperinsulinemia. Conversely, IGF-1 increases insulin sensitivity
MRI
Management:
List 2 management options knowing the cause?
Somatostatin analogues can be prescribed:
- How do they work?
- Give me an example - O
Pegvisomant can also be used. How does it work?.
Surgical excision
Radiotherapy
Somatostatin inhibits the release of GHRH (Growth hormone releasing hormone) from the hypothalamus.
Octreotide
Highly selective GH receptor antagonist
Long-term management:
Why is a colonoscopy, echo and DEXA scan done?
Because acromegaly increases the incidence of cancer and well as CVD and osteoporosis.
