Diagnosis of Adrenal Disorders

Question 1

What is the structure that is common to all steroids?

Answer 1

4 rings

Question 2

What is cortisol also know as?

Answer 2

Hydrocortisone

Question 3

What is cortisone?

Answer 3

Very weak glucocorticoid

Biologically inactive metabolite of cortisol

Question 4

What happens to cortisone after administration to a patient?

Answer 4

Metabolised to cortisol in liver

Question 5

What is the major glucocorticoid?

Answer 5

Cortisol

Question 6

What is the action of glucocorticoids?

Answer 6

Stimulation of gluconeogenesis in liver
Mobilisation of amino acids in muscle
Stimulation of lipolysis in adipose tissues
Immunosuppression

Question 7

What does too much cortisol lead to?

Answer 7

Weight gain
Wasting of
- Muscle
- Skin
- Bone
Hyperglycaemia
Salt retention > hypertension
Inhibition of linear growth

Question 8

What can cause ACTH-dependent hypercortisolism?

Answer 8

Pituitary adenoma = Cushing’s disease

Ectopic ACTH syndrome

Question 9

What can cause ACTH-independent hypercortisolism = Cushing’s syndrome?

Answer 9

Adrenal adenoma/carcinoma
ACTH-independent nodular hyperplasia
Administration of glucocorticoids

Question 10

What is the most common cause of Cushing’s syndrome?

Answer 10

Administration of glucocorticoids

Question 11

What happens in abnormal states when you deliberately stimulate/suppress the hormone to test for its function?

Answer 11

Hormone won’t rise into normal range when you stimulate it

Won’t fall into normal range if you suppress it

Question 12

What is a 24 hour urine assay useful for?

Answer 12

Tell you about variation throughout day

Question 13

How do you investigate suspected Cushing’s syndrome?

Answer 13

24 hour urine free cortisol
Check diurnal variation: serum cortisol and plasma ACTH
at
- 8 am
- 12 am
Check negative feedback loop working: dexamethasone suppression test
Cranial MRI/adrenal CT as indicated

Question 14

What is dexamethasone?

Answer 14

Very powerful glucocorticoid

Question 15

What happens when someone is given dexamethasone?

Answer 15

Should decreased ACTH and cortisol

Question 16

What does it mean if ACTH and cortisol don’t decrease when dexamethasone is given?

Answer 16

Something wrong with pituitary

Question 17

What does not enough cortisol cause?

Answer 17

Can't cope with new stress; eg: infection
- Much sicker than they should be
GI symptoms
- Anorexia
- Nausea
- Vomiting
- Diarrhoea
- Weight loss
Salt wasting > low BP
Darkening of skin if ACTH secretion stimulated
Muscle weakness
- Skeletal
- Cardiac

Question 18

What are the possible causes of adrenocortical insufficiency?

Answer 18

Genetic
- Enzyme defect in cortisol biosynthesis
- Metabolic defect = adrenoleukodystrophy
Autoimmne adrenal destruction
Infectious disease
- Adrenal destruction by TB

Question 19

What is the most common cause of Addison’s disease in Australia?

Answer 19

Autoimmune destruction of adrenal cortex

Question 20

What are the clinical findings for Addison’s disease?

Answer 20

Salt-wasting state > low Na and high K

Question 21

How do you treat Addison’s disease?

Answer 21

Cortisol

Fludrocortisone

Question 22

Where does Addisonian pigmentation commonly occur?

Answer 22

Knuckles of hands
Knees
Gums and oral mucosa
General pigmentation

Question 23

What happens when there is an excess of adrenal androgens?

Answer 23

Premature pubic hair
Hirsutism
Acne
Enlargement of penis/clitoris in child
Behavioural changes
Linear growth spurt
Rapid epiphyseal fusion in child
Muscular habitus
Deepening of voice

Question 24

What is the cause of congenital adrenal hyperplasia (CAH) in 90% of cases?

Answer 24

21-hydroxylase deficiency

Question 25

What is the inheritance pattern of CAH?

Answer 25

Autosomal recessive

Question 26

What is the pathophysiology of CAH?

Answer 26

Variable impairment of cortisol and aldosterone synthesis > ACTH stimulation > adrenal hyperplasia > increased androgen > virilisation

Question 27

What are the three different presentations of CAH in females?

Answer 27

Exposed to high levels of androgens in utero > infant with ambiguous genitalia In utero androgens not that high > happens more slowly > premature pubic hair and enlarged clitoris Adolescent hirsutism and acne

Question 28

What are the presentations of CAH in males?

Answer 28

Adrenal crisis in baby aged 2-3 weeks | Premature sexual development at age 2-3 years

Question 29

Why is there a decrease in oestrogen in CAH?

Answer 29

Made from testosterone and aromatase very tightly regulated | Do have slightly elevated levels

Question 30

What is the most commonly used steroid treatment?

Answer 30

Prednisolone

Question 31

What type of steroid is fludrocortisone?

Answer 31

Mineralocorticoid

Question 32

What regulates aldosterone secretion?

Answer 32

Increase K in ECF | Angiotensin II

Question 33

What are the actions of aldosterone?

Answer 33

Increased resorption of Na Increased resorption of water Increased excretion of K from kidney distal tubule

Question 34

What does excess aldosterone (Conn's syndrome) cause?

Answer 34

Salt retention > hypertension Hypokalaemia > weakness Low renin

Question 35

What does a deficiency in aldosterone cause?

Answer 35

Dehydration Salt depletion Postural hypotension Hyperkalaemia > cardiac arrhythmias

Question 36

What are possible causes of Conn's syndrome?

Answer 36

Adrenocortical tumour secreting aldosterone

Question 37

What is the treatment for Conn's syndrome?

Answer 37

Surgery

Question 38

What does pheochromocytoma cause?

Answer 38

Secrete large amounts of adrenaline and noradrenaline from adrenal medulla