Hypersecretion of anterior pituitary hormones Flashcards
Hyperpituitarims usually due to
Isolated pituitary tumours
but can also be ectopic
What other organ does it often lead to problems with?
Eyes- visual field defects
Pituitary tumour compresses the optic chiasm
What is bitemporal hemianopia?
A pituitary tumour projects out of the sella turcica and interferes with the optic chiasm especially the fibres coming from the nasal parts of the retinae which leads to loss of the temporal part of the visual field
What is hyperpituitarism of ACTH corticotrophin known as?
What is hyperpituitarism of TSH known as?
What is hyperpituitarism of Gonadotrophins (LH/FSH) corticotrophin known as?
What is hyperpituitarism of GH known as?
Cushing’s
Thyrotoxicosis
Precocious puberty in children
Gigantism– Children, Acromegaly– Adults
What is hyperprolactinaemia?
Excess circulating prolactin when not due to a physiological cause such as pregnancy and breast feeding
What is the most common type of prolactinoma?
Prolactinoma -Microadenoma
What is the effect of high prolactin levels on the reproductive axis?
Effect
Prolactin released by what cells
These cells express what receptors for dopamine
Decreases LH and FSH leading to secondary amenorrhoea/oligomenorrhoea, galactorrhea, loss of libido and infertility, impotence
Lactotrophs
D2 receptors
Treatment of hyperprolactinaemia
E.g of drug names
Side effects
D2 agonists
-reduce tumour size
BROMOCRIPTINE, CABERGOLINE - oral admin
Nausea and vomitting Postural hypotension Diskinesias Depression Pathological gambling- umpulse control disorder
What is the difference between gigantism and acromegaly?
In adults (acromegaly), the growth plates of the long bones have already fused so there is no longer a possibility of an increase in height but you still get other effects
Excess growth hormone usually due to
What is the onset of acromegaly like?
Benign growth hormone secreting pituitary adenoma.
Insidious
If gigantism/acromegaly is untreated, what happens?
Increase in morbidity/mortality
-cardiovasular, Resp, cancer
In acromegaly, what is there increased growth of? (5)
Periosteal bone Cartilage Fibrous tissue Connective tissue Internal organs
What are common clinical manifestations of acromegaly? (13)
Excessive sweating -hyperhidrosis
Headache
Enlargement of supraorbital ridges, nose, hands and feet, thickening of lips and general coarseness of features
Macroglossia
Mandible grows causing portrusion of lower jaw -PROGNATHISM
Carpal tunnel syndrome
Barrel chest, kyphosis
What is carpal tunnel syndrome?
Metabolic effects of acromegaly
When your hands shake due to increased cartilaginous growth increasing the pressure on the nerves
Median nerve compression
-Excess growth hormone –> increased endogenous glucose production, decreased muscle glucose uptake
increased insulin production=increased insulin resistance–>impaired glucose tolerance–> DM
Complications of acromegaly
Acromegaly secretion of Prolactin and GH
Obstructive sleep apnoea
-bone and soft tissue around upper airway narrowed and collapse
Hypertension
-Direct effect of GH or IGF-1 on vascular tree
-GH mediated renal Na Reabsorption
Cardiomyopathy
-Hypertension, DM, direct toxic effects of excess GH on myocardium
Increased risk of cancer
-Colonic polyps, regular screening with colonsocopy
Co-secretion of prolactin and growth hormone in acromegaly
