Cushing's, Hypopituitarism and Diabetes Insipidus Flashcards
What happens in Cushing’s syndrome
Excess cortisol
Protein loss
Excess Mineralocorticoid
Excess androgen
Why is there an increase in blood sugars in Cushing’s syndrome
Carbohydrates are not being metabolised and are laid down as fat stores instead
where is muscle wasting likely to be seen
Proximally - the shoulders and limb girdles
What does excess androgen cause
Virilism
Hirsutism
Acne
Oligo/ amenorrhoea
What are some characteristics of Cushing’s that are not true of Obesity
Thin skin Proximal myopathy Frontal balding in women Conjunctival oedema (chemosis) Osteoporosis
Describe the appearance of a cushing’s patient’s body
matchstick like
What test do we do to test for Cushing’s syndrome
Giving exogenous steroid (dexamethasone) which should suppress serum cortisol
What are some other tests we can do to diagnose cushing’s
Urine free cortisol
Diurnal cortisol variation
What are the ectopic reasons for developing Cushing’s
Thymus, lung or pancreas tumours producing ACTH
If the pituitary was the problem for Cushing’s, what would be seen
ACTH of less than 300
If an ectopic site was the problem for Cushing’s what would be seen
An ACTH of more than 300
What would be the effect of a high dose dexamethasone suppression test if the problem was
a) pituitary
b) adrenal
c) ectopic
a) suppressed by 50%
b) nil
c) nil
What is the treatment for a pituitary causing Cushing’s
Hypophysectomy (removal of tumour)
What is the treatment for an adrenal causing Cushing’s
Adrenalectomy
What is the treatment for an ectopic cause of Cushing’s
Remove source or bilateral adrenalectomy
When would drug treatment for Cushing’s disease be appropriate
When surgery has failed
What drugs can be used for Cushing’s
Metyrapone
Ketoconazole
Pasireotide
What hormones does the anterior pituitary produce and what happens in pan hypopituitarism
Growth hormone (growth failure) TSH (hypothyroidism) LH/FSH (hypogonadism) ACTH (hypoadrenal) Prolactin (none)
What can occur if there is hypopiutiarism in the posterior pituitary
diabetes insipidus
What are some of the causes of hypopituitarism
Pituitary tumours secondary metastatic lesions local brain tumours granulomatous diseases Trauma Infection
What are some signs of anterior hypopituitarism in females
Menstrual irregularities Infertility Abdominal obesity Loss of axillary and pubic hair Dry skin and hair Hypothyroid faces
What are some signs of anterior hypopituitarism in males
Infertility, impotence Gynaecomastia Abdominal obesity Loss of facial hair loss of axillary and pubic hair dry skin and hair hypothyroid faces
what is a sign of hypopituitarism in children
growth retardation
What are the benefits of growth hormone in adults
improves well being and quality of life decreases abdominal fat increases muscle mass improves cardiac function decreases cholesterol and increases LDL increases bone density
How is growth hormone given
Daily SC injection
How can testosterone be replaced
IM injection every 3-4 weeks
skin gel or prolonged IM injection every 12 weeks
what are the main problems with tablets to replace testosterone
they can cause liver toxicity
What are some of the risks of testosterone replacement
prostate enlargement (not cancer)
Polycythaemia
Hepatitis (oral tablets)
What test can we do to diagnose diabetes insipidus
Water deprivation test
What is the best screening test for Cushing’s syndrome
A 1mg overnight dexamethasone suppression test
Can testosterone cause polycythaemia
Yes
