Hyposecretion of Anterior Pituitary Hormones

Question 1

What is the difference between primary, secondary and tertiary endocrine gland disease?

Answer 1

Primary: problem with the endocrine gland/hormone released
Secondary: problem with the pituitary gland/hormone released
Tertiary: problem with the hypothalamus

Question 2

What is the term given to decreased production of all anterior pituitary hormones?

Answer 2

Panhypopituitarism

Question 3

List 3 characteristics of congenital panhypopituitarism

Answer 3

Deficient in GH + at least 1 other anterior pituitary hormone
Short stature
Hypoplastic anterior pituitary on MRI

Question 4

In what order does loss of secretion occur?

Answer 4

Usually develops in adults with progressive loss of pituitary secretion
Gonadotrophins  
GH
Thyrotrophin 
Adrenocorticotrophin 
Prolactin

Question 5

What are 3 main types of panhypopituitarism?

Answer 5

Simmond’s Disease
Sheehan’s Syndrome
Pituitary Apoplexy

Question 6

Describe the symptoms experienced due to lack of FSH/LH, ACTH and TSH in Simmond’s disease

Answer 6

FSH/LH: Reduced libido, Secondary amenorrhoea, Erectile dysfunction
ACTH: Fatigue
TSH: Fatigue

Question 7

State the cause of Sheehan’s syndrome and describe its onset.

Answer 7

Specific to postpartum women, secondary to hypotension caused by PPH.
Pituitary enlarges in pregnancy (lactotroph hyperplasia)
PPH reduces blood supply, causes pituitary infarction and thus hypopituitarism

Question 8

What is pituitary apoplexy? Describe its onset.

Answer 8

Intra-pituitary haemorrhage or infarction.
Dramatic presentation, rapid onset
May be 1st presentation of pituitary adenoma
May be precipitated by anti-coagulants

Question 9

Why is a single measurement of most hypothalamic hormones not useful?

Answer 9

Most hypothalamic hormones tend to be released in pulses

Question 10

What do you do to test if someone is producing a hormone?

Answer 10

Stimulated Pituitary Function Test

Question 11

What are the effects of a lack of somatotrophin in children and in adults?

Answer 11

Children: short stature (2 SDs < mean)
Adults: loss of GH effects are less clear

Question 12

State 7 causes of short stature.

Answer 12

Genetic  
Emotional deprivation  
Endocrine disorders
Malnutrition 
Malabsorption
Skeletal dysplasias
Systemic disease

Question 13

Describe 3 causes of short stature, each with their error being in a different part of the growth axis

Answer 13

Hypothalamic dysfunction, lack of GHRH (PWS)
Lack of GH (Pituitary dwarfism)
GH receptor defect (Laron dwarfism)

Question 14

What are most endocrine-related causes of short statue due to (with reference to the HP axis)?

Answer 14

Decreased production of GHRH

Question 15

State which other hormones are produced in response to GH stimulation, where they are produced and their effects.

Answer 15

IGF I = insulin-like growth factor I + IGF II
Produced in LIVER
Mediate growth

Question 16

State 3 characteristics of achondroplasia

Answer 16

Mutation in FGF receptor 3
Average size trunk
Short arms + legs

Question 17

Name 4 causes of acquired GH deficiency in adults

Answer 17

Trauma
Pituitary tumour
Pituitary surgery
Cranial radiotherapy

Question 18

What test is primarily used to diagnose GH deficiency?

Answer 18

Insulin-induced hypoglycaemia

Hypoglycaemia is a potent stimulus for GH release

Question 19

State 3 other triggers for an increase in GH release.

Answer 19

GHRH + Arginine (i.v.)
Glucagon (i.m.)
Exercise (in kids)

Question 20

Describe how the insulin-induced hypoglycaemia test is used to test GH secretion.

Answer 20

Normal: massive rise in GH secretion

GH Deficiency: GH response will be reduced

Question 21

For each of the following anterior pituitary hormone deficiencies, state the replacement used and the parameter that is monitored during treatment:

a. ACTH
b. TSH
c. Women - LH/FSH
d. Men - LH/FSH
e. GH

Answer 21

a. ACTH 
Give hydrocortisone 
Monitor serum cortisol 
b. TSH 
Give thyroxine 
Monitor serum fT4
c. Women – LH/FSH 
Give E2 + progestagen
Monitor symptom improvement + withdrawal bleeds
d. Men – LH/FSH 
Give testosterone
Monitor symptom improvement + serum testosterone
e. GH
Give GH  
Monitor IGF I or use growth chart (kids)

Question 22

How is the human recombinant GH administered, how frequently must it be given and what further action is taken?

Answer 22

Subcutaneous injection daily

Monitor clinical response + adjust dose based on IGF-1 levels

Question 23

State 4 signs and symptoms of GH deficiency in adults.

Answer 23

Reduced lean mass, Increased adiposity, Increased waist: hip ratio
Decrease plasma HDL + increased LDL
Reduced muscle strength + bulk
Impaired psychological wellbeing + quality of life

Question 24

Name 5 potential benefits of GH therapy in adults

Answer 24

Improved body composition
Improved muscle strength + exercise capacity
Normalisation of HDL-LDL
Increased bone mineral density
Improved psychological wellbeing + quality of life

Question 25

What are the potential risks of GH therapy in adults?

Answer 25

Increased susceptibility to cancer (but no evidence to support this)
Expensive

Question 26

List the anterior pituitary hormones

Answer 26

FSH + LH
Prolactin 
Growth Hormone
Thyroid Stimulating hormone
ACTH

Question 27

What are the general causes of hypopituitarism?

Answer 27

Congenital (rare)

Acquired

Question 28

List 8 causes of acquired panhypopituitarism

Answer 28

Tumour
Radiation
Infecion
Traumatic brain injury
Infiltrative disease
Inflammatory
Pituitary apoplexy
Peri-partum infection

Question 29

Describe presentation of Sheehan’s syndrome

Answer 29

Lethargy
Anorexia/ Weight loss
Failure of lactation
Failure to resume menses post-delivery

Question 30

Why may pituitary apoplexy/adenoma cause visual field defects and headaches?

Answer 30

Compresses optic chiasm
Causes bitemporal hemianopia (loss of outer fields)
If squashing CN 4 or 6 in cavernous sinus = Diplopia
If squashing CN 3 = Ptosis

Question 31

Describe a stimulated pituitary function test

Answer 31

Induce hypoglycaemia
Causes patient to produce GH + ACTH + hence cortisol (measured)
Give TRH to stimulate TSH (measure)
Give GnRH to stimulate FSH/ LH (measure)

Question 32

What form of radiological test may be used to diagnose hypopituitarism?

Answer 32

MRI

May reveal specific pituitary pathology e.g. haemorrhage, adenoma, empty sella

Question 33

What is used to predict adult height?

Answer 33

Mid parental height