pituitary endocrinology

Question 1

Why is it important to know when in the day hormones are secreted in the body?

Answer 1

Need to know if diurnal or circadian variation for endocrine tests to decide what time of day to do the test

Question 2

What are some signs and symptoms of insufficient levels of the following hormones:

GH
Gonadotrophins (FSH/LH)
TRH

Answer 2

GH: central obesity, atherosclerosis, dry skin, osteoporosis, decreased well being

FSH/LH: oligomenorrhoea, decreased fertility, decreased libido, osteoporosis, breast atrophy, impotence, decreased muscle bulk, small testes

TRH: hypothyroidism

Question 3

What is pituitary apoplexy and how does it present?

Answer 3

Bleeding into a pituitary tumour or reduced blood supply to the pituitary gland

Can cause mass effects, cardiovascular collapse due to acute hypopituitarism and death

Presentation: acute onset headache, meningism, visual field defects, reduced GCS

Question 4

How may hypopituitarism present?

Answer 4

Non-specific symptoms e.g lethargy, weight gain, sexual dysfunction

Can present as hypo-adrenal crisis with hypoNa and hypotension as lack of ACTH

Question 5

What investigations should you do for suspected hyperprolactinaemia e.g infertility, galactorrhea?

Answer 5

• Pregnancy test to rule out prenancy
• TFTs to check for hypothyroidism
• U+Es
• MRI pituitary

Check medication history

Question 6

What are some signs and symptoms of acromegaly?

Answer 6

Symptoms: acroparaesthesia, snoring due to enlargement of tongue, carpal tunnel syndrome from puffy hands, increased sweating, headaches, hypertension

Signs (see image): increased size of hands and feet, coarse facial features, frontal bossing of forehead, protrusion of chin, diabetes

Question 7

Why can’t you measure basal GH to diagnose acromegaly?

Answer 7

Secretion is pulsatile and during peaks GH can be raised to acromegaly levels.

Also high glucose usually suppresses GH

GH raised by: stress, sleep, puberty, pregnancy

Question 8

What are some symptoms of growth hormone deficiency in adults?

Answer 8

Reduced QoL
Reduced muscle and bone mass
Increased fat mass
Cardiovascular risk

Question 9

What are some causes of hyponatraemia?

Answer 9

SIADH
Drugs e.g diuretics
GI losses e.g diarrhoea, vomiting
IV fluids with constant 5% dextrose
Burns
Renal failure
Water overload
Addison’s
Hypothyroidism

Question 10

How do NSAIDs and diuretics like bendroflumethiazide help to managed nephrogenic DI?

Answer 10

They inhibit prostaglandin synthesis and prostaglandins normally inhibit action of ADH

Question 11

What is the emergency management for DI causing hypernatraemia?

Answer 11

• Urgent U+Es and serum/urine osmolalityies
• Monitor urine output
• IVI fluids to keep up fluids with urine output. If severe HyperNa lower Na slowly so as not to cause cerebral oedema and cause a brain injury
• Consider desmopressin s/c or IM