hyposecretion of anterior pituitary disorders

Question 1

what is a primary endocrine disorder?

Answer 1

disorder lies in endocrine gland

Question 2

what is a secondary endocrine disorder?

Answer 2

disorder lies in anterior pituitary

Question 3

what is a tertiary endocrine disorder?

Answer 3

disorder lies in hypithalamus

Question 4

what is panhypopituitarism?

Answer 4

dec. production of all adenohypophysial hormones

congenital (rare) or acquired

Question 5

what are the causes of congenital panhypopituitarism?

Answer 5

due to mutations of TF genes needed for normal pituitary development

Question 6

what is the outcome and signs of this?

Answer 6

deficiency of GH and at least 1 other pituitary hormone

get short stature

Question 7

what are the different types of acquired panhypopituitarism?

Answer 7

• tumours: hypothalamic, pituitary
• radiation
• infection
• TBI
• infiltrative disease
• pituitary apoplexy
• peri-partum infarction (Sheehan’s syndrome)

Question 8

what are the symptoms of FSH/LH deficiency?

Answer 8

secondary hypogonadism

• reduced libido
• secondary amenorrhoea
• erectile dysfunction

Question 9

what are the symptoms of ACTH deficiency?

Answer 9

secondary hypoadrenalism (cortisol def)
- fatigue

Question 10

what are the symptoms of TSH deficiency?

Answer 10

secondary hypothyroidism

• fatigue
• weight gain

Question 11

what is Sheehan’s syndrome?

Answer 11

• post-partum hypopituitarism secondary to hypotension
• anterior pituitary often enlarges in pregnancy, hypotension from loss of blood from giving birth can mean the pituitary becomes under perfused and then infarcts

Question 12

what is the presentation of Sheehan’s syndrome?

Answer 12

• lethargy
• anorexia
• weight loss
• failure of lactation
• failure to resume menstrual cycles post delivery

Question 13

what is pituitary apoplexy?

Answer 13

• intra-pituitary haemorrhage/infarction
• dramatic presentation in patients w/ pre-existing pituitary adenoma
• precipitates by anti-coagulants

Question 14

what are the symptoms of pituitary apoplexy?

Answer 14

• severe sudden onset headache
• bitemporal hemianopia (pressing on optic chiasm)
• diplopia
• ptosis

Question 15

when ACTH is deficient, what is used to replace it? what should you check?

Answer 15

hydrocortisone

serum cortisol

Question 16

when TSH is deficient, what is used to replace it? what should you check?

Answer 16

thyroxine

serum free T4

Question 17

when women LH/FSH is deficient, what is used to replace it? what should you check?

Answer 17

HRT

symptom improvement, withdrawal bleeds

Question 18

when men LH/FSH is deficient, what is used to replace it? what should you check?

Answer 18

testosterone

symptom improvement, serum testosterone

Question 19

when GH is deficient, what is used to replace it? what should you check?

Answer 19

GH

IGF1, growth chart (children)

Question 20

what are the different biochemical tests you can do to diagnose hypopituitarism?

Answer 20

• basal plasma conc of target endocrine gland hormone

- stimulated pituitary function tests

Question 21

describe the basal plasma conc levels of:
cortisol
T4
FSH/LH
GH/ACTH

Answer 21

• cortisol: small volumes, varies throughout day
• T4: long half life, take a while to fall
• FSH/LH: cyclical
• GH/ACTH: pulsatile

Question 22

describe the stimulated pituitary function tests

Answer 22

• ACTH and GH = stress hormones
• stress = hypoglycaemia
• insulin induces hypoglycaemia stimulates GH and ACTH release
• TRH in injection stimulates TSH release
• GnRH stimulates FSH and LH release

Question 23

how can be radiology be used for diagnosis?

Answer 23

pituitary MRI

Question 24

what is the short stature definition in children?

Answer 24

<2SDs from mean

Question 25

what are the causes of short stature?

Answer 25

- genetic - emotional deprivation - systemic disease - malnutrition - malabsorption - endocrine disorders - skeletal dysplasia

Question 26

what is dwarfism?

Answer 26

achondroplasia - mutation in FGF3 - abnormalities in growth plate chondrocytes that impairs linear growth - results in average sized trunk and short arms/legs

Question 27

what causes pituitary dwarfism?

Answer 27

childhood GH def

Question 28

what causes Prader Willi syndrome?

Answer 28

GH deficiency secondary to hypothalamic dysfunction

Question 29

what causes laron dwarfism?

Answer 29

high local incidence | mutation in GH receptor treated with IGF-1 in childhood

Question 30

what are the causes of acquired GH def in adults?

Answer 30

- trauma - pituitary tumour/surgery - cranial radiotherapy

Question 31

how can you diagnose acquired GH def in adults?

Answer 31

- Provocative challenge (stimulation) test - cannot measure GH as it is pulsatile - GHRH + arginine (IV), insulin (IV), glucagon (IM), exercise - plasma GH measured at specific time points after - normally insulin causes peak in GH

Question 32

what is the response to hypoglycaemia in GH deficient people?

Answer 32

GH def people have a low GH response

Question 33

what is the metabolism and DoA of GH therapy?

Answer 33

- max conc in plasma in 2-6 hours - hepatic/renal metabolism with short half life of 20mins - lasts well beyong clearance, peak IGF1 levels at approx 20 hrs

Question 34

what are the symptoms of GH deficiency?

Answer 34

- reduced lean mass - reduced muscle strength - dec. plasma HDL - impaired psychological well-being - inc. adiposity - reduced exercise performance - raised LDL

Question 35

what are the risks of GHRT?

Answer 35

- inc. susceptibilty to cancer | - expensive