Adrenal Disorders

Question 1

Which part of the adrenal gland is responsible for producing mineralocorticoids?

Answer 1

Zona glomerulosa

Question 2

What are the three components of the adrenal cortex?

Answer 2

1. Zona glomerulosa
2. Zona fasiculata
3. Zona reticularis

Question 3

What regulates the zona glomerulosa?

Answer 3

1. K+ concentration
2. Angiotensin II (RAAS)

Question 4

Which part of the adrenal gland produced glucocorticoids and in response to what?

Answer 4

Zona fasiculata

ACTH

Question 5

The medulla of the adrenal gland is responsible for secreting what?

Answer 5

Catecholamines

Question 6

What is the zona reticularis responsible for secreting?

Answer 6

Androgens

Question 7

How are cortisol and androgen production regulated?

Answer 7

Hormones from the hypothalamus and anterior pituitary

Question 8

Describe the steps which lead to cortisol production

Answer 8

Hypothalmic-pituitary-adrenal axis

Hypothalamus releases corticotropin releasing hormone

Anterior pituitary releases adrenocorticotropin hormone (ACTH)

Adrenal cortex releases cortisol

Question 9

When is the RAAS pathway activated?

Answer 9

Low blood pressure

Question 10

What is the result of an activated RAAS pathway?

Answer 10

Increased BP

1. Angiotensin II causes vasoconstriction
2. Aldosterone causes salt (and water) retention

Question 11

What are the 6 classes of steroid receptors?

Answer 11

1. Androgen
2. Glucocorticoid
3. Mineralocorticoid
4. Oestrogen
5. Progestin
6. Vitamin D

Question 12

The following signs and symptoms are characteristic of what?

1. Darkened skin
2. Dehydration
3. Hypotensive
4. Hyponatraemia

Answer 12

Primary adrenal insufficiency

Question 13

What are the three main causes for primary adrenal insufficiency?

Answer 13

1. Addison’s disease
2. Congenital adrenal hyperplasia
3. Adrenal Tb or malignancy

Question 14

Secondary adreanl insufficiency may be due to which 3 main causes?

Answer 14

1. Lack of ACTH stimulation
2. Iatrogenic (excess exogenous steroid)
3. Pituitary/hypothalmic disorders

Question 15

Addison’s disease is associated with other _________ conditions and in most cases auto_________

Answer 15

Addison’s disease is associated with other autoimmune conditions and in most cases autoantibodies

Question 16

What are the key clinical features of Addison’s disease?

Answer 16

1. Anorexia and weight loss
2. Fatigue
3. Dizziness and low BP
4. Abdominal pain, nausea and vomiting
5. Skin pigmentation

Question 17

Why is Addison’s disease associated with skin pigmentation?

Answer 17

Build up of ACTH

Question 18

How can adrenal insufficiency be diagnosed?

Answer 18

Synacthen test

Measure plasma cortisol before and 30 minutes after IV/IM ACTH injection

Normal = >250nmol/L (before), >550nmol/L (after)

Question 19

Adrenal insufficiency is associated with _____glycaemia

Answer 19

Adrenal insufficiency is associated with hypoglycaemia

Question 20

How is adreanl insufficiency treated?

Answer 20

1. Hydocortisone (cortisol replacement)
2. Fludrocortisone (aldosterone replacement)

Question 21

The clinical features of secondary adrenal insufficiency are similar, except for which two things?

Answer 21

1. Pale skin (there is not excess ACTH)
2. Aldosterone production is intact

Question 22

What are the facial features of someone with Cushing’s syndrome?

Answer 22

1. Moon face
2. Plethoric (flushed) cheeks/acne
3. Cataracts

Question 23

How is the skin affected in Cushing’s syndrome?

Answer 23

1. Buffalo hump
2. Thin skin/easy bruising
3. Increased abdominal fat
4. Striae

Question 24

What are the most common causes of ACTH dependent Cushing’s syndrome?

Answer 24

1. Pituitary adenoma*
2. Ectopic ACTH (tumour)
3. Ectopic CRH

*Cushing’s disease

Question 25

What are the causes of ACTH independent Cushing's?

Answer 25

1. Exogenous steroids 2. Adrenal adenoma 3. Adremal carcinoma 4. Nodular hyperplasia

Question 26

Which tests can be done to establish a cortisol excess in suspected Cushing's?

Answer 26

1. **Overnight dexamethasone suppression test** 2. 24 hour urinary free cortisol 3. Late night salivary cortisol

Question 27

Which test is generally done to diagnose Cushing's?

Answer 27

Low dose dexamethasone suppression test

Question 28

What is the commonest cause of cortisol excess?

Answer 28

Iatrogenic (exogenous steroids)

Question 29

What is the downside to chronic exogenous steroid use?

Answer 29

**Chronic suppression** of pituitary ACTH Adrenal atrophy will occur

Question 30

What is Conn's syndrome?

Answer 30

Primary aldosteronism (due to adrenal adenoma)

Question 31

How does primary aldosteronism come about?

Answer 31

Autonomous aldosterone production (independent of angiotensin II/ K⁺ conc)

Question 32

What are the actions of aldosterone in the body?

Answer 32

1. Increases sympathetic outflow 2. Sodium retention 3. Cytokine and ROS synthesis 4. Increased cardiac collagen synthesis 5. Endothelial dysfunction

Question 33

What is the most common secondary cause of hypertension?

Answer 33

Primary aldosteronism

Question 34

What are the key clinical features of primary aldosteronism?

Answer 34

1. Hypertension 2. Hypokalaemia 3. Alkalosis

Question 35

What are the two main subtypes of primary aldosteronism?

Answer 35

1. Adrenal adenoma (Conn's) 2. Bilateral adrenal hyperplasia

Question 36

How is primary aldosteronism diagnosed?

Answer 36

1. Measure plasma aldosterone to renin ratio 2. If ratio is raised, attempt saline suppression test 3. Failure of plasma aldosterone to suppress by \>50% with 2L of normal saline confirms PA

Question 37

How can the subtype of primary aldosteronism be confirmed?

Answer 37

Adrenal CT (demonstrates adenoma) PET scan (demostrates adenoma/bilateral hyperplasia)

Question 38

What are the treatment options for primary aldosteronism a) Caused by adenoma b) Caused by bilateral adrenal hyperplasia?

Answer 38

a) Unilateral laparoscopic surgery b) MR antagonists e.g. spironolactone