Hypoadrenal disorders

Question 1

How many carbons does cholesterol have?

Answer 1

27

Question 2

How do you get different substances from cholesterol?

Answer 2

You hydroxylate it at different positions

Question 3

What is the most common cause of adrenocortical failure worldwide?

Answer 3

Tuberculous Addison’s disease

Question 4

When does tuberculous addison’s particularly occur?

Answer 4

When you stop a course of treatment early

Question 5

What is the most common cause of adrenocortical failure in the UK?

Answer 5

Autoimmune Addison’s disease- immune system makes a mistake and wipes out adrenal gland

Question 6

What is congenital adrenal hyperplasia?

Answer 6

When you are born with big adrenal glands and that is caused by enzyme deficiency so the adrenals can’t make the hormones properly

Question 7

How do Addison’s patients present?

Answer 7

They have darker hair, increased skin pigmentation and patches of vitiligo

Question 8

What are the consequences of adrenal failure?

Answer 8

Fall in blood pressure- no aldosterone
Loss of salt in urine- unable to retain salt due to lack of aldosterone
Increased plasma potassium
Fall in blood glucose- glucocorticoid deficiency
High ACTH resulting in increased pigmentation
Eventual death due to severe hypotension- if it happens suddenly its an Addisonian crisis

Question 9

What are the two components of POMC (pro-opiomelanocortin)

Answer 9

ACTH and MSH

Question 10

Explain the link between adrenal failure and increased pigmentation?

Answer 10

Due to adrenal gland failure, there is no cortisol which means that there is no negative feedback on ACTH so there is high ACTH and ACTH is formed in the pituitary by POMC being broken down into ACTH and MSH so there is also high MSH and increased pigmentation

Question 11

How do you test for Addison’s?

Answer 11

Measure the hormones at 9 am and their cortisol should be high, if it’s not they might have Addison’s
You could measure their ACTH and that should be really high
You could inject them with synthetic ACTH (synacthen) and they should make a lot of cortisol in response if normal

Question 12

How does the 9am cortisol of an Addison’s patient compare to the normal range?

Answer 12

Low- around 100 (normal is 270-900)

Question 13

What is the commonest cause of congenital adrenal hyperplasia?

Answer 13

21-hydroxylase deficiency

Question 14

Is congenital adrenal hyperplasia evident in utero?

Answer 14

No because you receive the hormones from your mother

Question 15

What hormones can someone with 21-hydroxylase not produce?

Answer 15

Cortisol and aldosterone

Question 16

What happens to sex steroids in someone with 21 hydroxylase deficiency?

Answer 16

They can still make them because there is an overflow of 17-hydroxyprogesterone, they will make a lot of sex steroids but can’t make anything else

Question 17

What happens if cortisol and aldosterone are completely absent?

Answer 17

You can’t survive longer than a day

Question 18

What is the first thing a doctor would do to treat congenital adrenal hyperplasia?

Answer 18

Give IV saline- good because you’ve lost salt

Question 19

Why do congenital adrenal hyperplasia have genital defects?

Answer 19

Excess testosterone- especially noticeable in girls

Question 20

How does congenital adrenal hyperplasia present?

Answer 20

Hypotension
Virilisation
Abnormality of genitalia

Question 21

What is virilisation?

Answer 21

Development of male characteristics in a female

Question 22

What happens in partial 21-hydroxylase deficiency?

Answer 22

You’ll have low cortisol and be a little hypotensive but won’t die and will have a long period of slightly raised testosterone

Question 23

What happens in 11 beta hydroxylase deficiency?

Answer 23

You get build up of 11 deoxycorticosterone

Question 24

What is 11 deoxycorticosterone?

Answer 24

Aldosterone receptor agonist

Question 25

How does 11 beta hydroxylase deficiency present?

Answer 25

You don’t have a salt losing Addisonian crisis but behave like they have a high level of aldosterone so:
Hypertensive in childhood
Hypokalaemic
Virilised

Question 26

What happens in 17 beta hydroxylase deficiency?

Answer 26

High levels of aldosterone (hypertensive and hypokalaemic) but no cortisol and sex steroids so will never go through puberty and are borderline hypoglycaemic