pituitary

Question 1

replacement and check if GH deficient

Answer 1

GH; IGF1, growth chart (children)

Question 2

other name of growth hormone

Answer 2

somatotrophin

Question 3

effect of GH deficiency in children

Answer 3

short stature (2 s.ds < mean height for that age and sex); can give GH if proved deficient

Question 4

7 categories of short stature causes

Answer 4

genetic, emotional deprivation (stress axis), systemic disease, malnutrition, malabsorption, endocrine disorders, skeletal dysplasias

Question 5

3 genetic causes of short stature

Answer 5

Down’s syndrome, Turner’s syndrome, Prader Willi syndrome

Question 6

2 systemic diseases causing short stature

Answer 6

cystic fibrosis, rheumatoid arthritis

Question 7

malabsorption cause of short stature

Answer 7

coeliac disease

Question 8

4 endocrine diseases causing short stature

Answer 8

Cushing’s syndrome (excess cortisol), hypothyroidism, GH deficiency, poorly controlled type 1 diabetes mellitus

Question 9

2 skeletal dysplasias causing short stature

Answer 9

achondroplasia, osteogenesis imperfecta

Question 10

growth axis of somatotrophin

Answer 10

hypothalamus -> GHRH (inhibited by somatostatin) -> adenohyphysis -> somatotrophin -> direct: target tissues; indirect: liver -> release of IGFI (and IGFII) -> target tissues

Question 11

growth axis: where does Prader Willi syndrome affect

Answer 11

hypothalamus, so GHRH and consequently GH deficiency; secondary to hypothalamic dysfunction

Question 12

growth axis: cause of short stature due to pituitary dwarfism

Answer 12

lack of somatotrophin released

Question 13

growth axis: cause of Laron dwarfism

Answer 13

GH receptor defect in liver

Question 14

dwarfism: achondroplasia: mutation

Answer 14

mutation in fibroblast growth factor receptor 3 (FGF3)

Question 15

dwarfism: achondroplasia: what causes impaired linear growth

Answer 15

abnormality in growth plate chondrocytes so skeletal issue

Question 16

dwarfism: achondroplasia: clinical presentation

Answer 16

average trunk size, short limbs

Question 17

dwarfism: pituitary

Answer 17

childhood GH deficiency

Question 18

dwarfism: Laron dwarfism: mutation and treatment

Answer 18

mutation in GH receptor; treated with IGF1 in childhood to increase height

Question 19

diagnosis of short stature: mid-parental height

Answer 19

predicted adult height based on father’s and mother’s height

Question 20

diagnosis of short stature: monitoring height

Answer 20

drop of more than 2 centiles is flagged and investigated (e.g. coeliac disease so gluten-free diet then continues to grow at normal rate)

Question 21

4 causes of acquired GH deficiency in adults, and what they affect

Answer 21

trauma, pituitary tumour, pituitary surgery, cranial radiotherapy; all affect region before reaching liver or target tissues (secondary disease)

Question 22

how is GH deficiency diagnosed in adults

Answer 22

as GH is pulsatile, random GH test is of little use; instead, provocative challenge (stimulation test)

Question 23

GH provocation tests: 4 factors and measurement

Answer 23

GHRH and arginine (may inhibit somatostatin release) injected (i.v.), insulin (promote hypoglycaemia) injected (i.v.), glucagon (causes secretion of ACTH and GH as causes vomiting, causing stress) injected (i.m.), exercise (e.g. 10 min step climbing when appropriate); measure plasma GH at specific points before and after

Question 24

GH secretion in response to hypoglycaemia (insulin tolerance test)

Answer 24

normally increases hugely upon IV insulin injection (above NICE cut-off of 3mcg/L), but if GH deficient then won’t reach cut-off so warrant treatment

Question 25

GH therapy preparation

Answer 25

human recombinant GH (somatotropin); not usually required in adults as finished growing

Question 26

GH therapy administration

Answer 26

daily, subcutaneous injection; monitor clinical response and adjust dose to IGF1

Question 27

4 signs and symptoms of GH deficiency in adults

Answer 27

reduced lean mass (increased adiposity and waist:hip ratio), reduced muscle strength and bulk (reduced exercise performance), decreased plasma HDL-cholesterol and raised LDL-cholesterol, impaired psychological well-being and reduced quality of life

Question 28

5 potential benefits of GH therapy in adults

Answer 28

improved body composition (reduced waist:hip ratio and less visceral fat), improved muscle strength, more favourable lipid profile (increased plasma HDL-cholesterol and decreased LDL-cholesterol), increased bone mineral density, improved psychological well-being and quality of life

Question 29

2 potential risks of GH therapy in adults

Answer 29

possibly increased susceptibility to cancer (helps cells to grow), expensive lifelong treatment

Question 30

what type of hormone is growth hormone

Answer 30

polypeptide (protein)

Question 31

are protein hormones absorbed well when given orally

Answer 31

no

Question 32

duration of action of protein vs steroid hormones

Answer 32

steroid hormones are longer acting (>24hrs)

Question 33

where do protein hormones act on

Answer 33

membrane-bound receptors