Growth Hormone Problems Flashcards
What is the main cause of Gh Hypersecretion
Tumours
What is gigantism
A rare condition that causes abnormal growth in children
What parameter is most obviously increased in children with gigantism
Height (but girth also affected)
What causes gigantism
Pituitary tumours
What are rarer causes of gigantism
Mccune-Albright syndrome
Carney Complex
Multiple endocrine neoplasia (MEN1)
Neurofibromatosis
What is Mccune-Albright syndrome
Causes abnormal growth in bone tissue, patces of brown skin and gland abnormalities
What is Carney complex
An inheritied condition that causes non-cancerious tumours on connective tissue, cancerours or non cancerous endocrine tumours and spots on darker skin
What is MEN1
inherited disorder causing tumours of pituitary gland, pancreas or parathyroid gland
What is neurofibromatosis
An inherited disorder that causes tumours in the nervous system
What are symptoms of gigantism
very large hands and feet thick toes and fingers Prominent jaw and forehead Coarse facial features excessive sweating Insomnia Delayed puberty irregular menstrual periods
How do you make the diagnosis of gigantism
Bloods (GH and IGF-1)
Oral glucose tolerance test
Why do a glucose tolerance test in gigantism
In acromegaly failure of suppression occurs, and there may be a paradoxical rise in GH in response to the glucose challenge.
What is treatment of gigantism
Surgical resection (transphenoidal)
What is acromegaly
The clinical manifestation of excessive growth hormone after epiphyeal plates have sealed. Long bones cant increase in height but they grow in other directions
What is the characteristic feature of acromegaly
Large hands and feet
What are the causes of acromegaly
Pituitary adenoma
Ectopic release of GHRH from a tumour elsewhere (bronchial carcinoid)
What are symptoms of acromegaly (x9)
Big features but same height Arthritis Organ dysfunction Headaches (if tumour) Bi-temporal heminaopea (if tumour) Carpal tunnel syndrome Lower voice pitch Macroglossia Sweating
What effects of organ dysfunction can be seen in acromegaly
Hypertrophic heart
Hypertension
Type-2 Diabetes
Colorectal cancer
What is treatment for acromegaly
Trans-sphenoidal surgery
Somatostatin analogues
Dopamine agonists
GH antagonists
Name a somatostatin analogue
Ocreotide
What do somatostatin analogues do?
They block GH release
Name a dopamine agonist
Bromocriptine
What do dopamine agonsit do
Block GH relase
Name a GH antagonist
Pegvisomant
What can cause hyposecretion of GH
A deficiency in GHRH
A deficiency in GH release from pituitary
Genetic mutations or underexpression of GH receptor
Precocious puberty
Hypothyroid dwarfism
What is precocious puberty?
Excess GnRH stimulates puberty early causing kids to have stunted growth
What are features of hypothyroid dwarfism
Children retain infantile features with stunted growth doe to loos of permissive effects of TH on GH.
What is the screening test for Acromegaly
IGF-1 levels
What is the diagnostic test for acromegaly
Oral glucose tolerance load test
What investigations should you do for someone with suspected acromegaly
Test IGF-1 levels Oral glucose tolerance load test Bloods (Glu, Calcium, Phosphate) Radiology Visual field exam ECHO/ECG
Why would you do an ECHO/ECG in acromegaly investigations
To assess for cardiovascular risk factors
