Acromegaly Flashcards
What is Acromegaly?
when there is excessive GH
produced by the anterior pituitary
What are the causes of acromegaly?
most common cause is pituitary adenoma (can be microsocpic or of significant size)
rarely can be due to cancers such as Lung or Pancreatic secreting ectopic Growth hormone releasing hormone (GHRH) or Growth hormone (GH)
How does acromegaly present?
Pituitary tumour: headaches, bilateral temporal heminopia, hypopituitarism
Overgrowth of tissue:
- Large forehead, nose, tongue (macroglossia), hands and feet
- large protruding jaw (proganthism)
- arthritis from imbalanced growth of joints
Organ dysfunction due to GH
- hypertrophic heart/cardiomyopathy
- htn
- T2DM
- colorectal cancer
signs of active raised GH
- excessive sweating and oily skin (sweat gland hypertrophy)
- development of new skin tags
other
- raised prolactin in 1/3
What investigations do you do for acromegaly?
GH levels vary during the day so not prognostic
- Serum IGF1 levels 1st line (raised)
- Oral glucose tolerance test (ogtt) whilst checking GH (high glucose normally suppresses GH)
- MRI brain for pituitary tumour
- refer to ophthalmology for visual field testing
What is the management of acromegaly
1st line: Trans-sphenoidal surgery first line in majority
Medication used if inoperable or surgery unsuccessful
- somatostatin analogue e.g Octreotide (directly inhibits GH release) 50-70% effective
- Pegvisomant - GH receptor antagonist. < IGF-1 levels in 90%, surgery still needed
- Dopamine agonists e.g Bromocriptine - effective only in minority, works similar to somatostatin analogue (preferable) but less inhibitory effect
What are the names of three drugs which can be used to manage Acromegaly?
Octreotide - somatostatin analogue
Pegvisomant - GH receptor antagonist
Bromocriptine - dopamine agonist
