Circadian Rhythms, adrenal insufficiency and management

Question 1

What is circadian rhythm?

Answer 1

physical, mental and behavioural changes that follow a daily cycle

Question 2

How is cortisol produced?

Answer 2

Hypothalamus produces CRH -> pituitary releases ACTH -> adrenal gland produces cortisol

Question 3

Define adrenal insufficiency (AI)

Answer 3

A condition in which the adrenal glands do not produce adequate amounts of steroid hormone (mainly cortisol)

Question 4

What is primary AI?

Answer 4

Addison’s disease

Question 5

What is secondary AI?

Answer 5

Hypopituitarism

Question 6

What is tertiary AI?

Answer 6

Suppression of HPA

Question 7

What are symptoms of AI?

Answer 7

fatigue, weight loss, poor recovery from illness, adrenal crisis, headache

Question 8

What past history may show AI?

Answer 8

TB, post partum bleed, cancer

Question 9

What family history might show AI?

Answer 9

Autoimmunity, congenital disease

Question 10

What would you treat AI with?

Answer 10

Any steroid

Question 11

What are signs of AI?

Answer 11

• Pigmentation and pallor
• Hypotension

Question 12

What biochemistry shows AI?

Answer 12

• Low Na, high K (SIADH like picture)
• Eosinophilia
• Borderline elevated TSH

Question 13

What investigations would you do to investigate AI?

Answer 13

• 0900 cortisol and ACTH
• Renin/ aldo
• Synacthen test

Question 14

What cortisol result signifies AI?

Answer 14

Cortisol < 100 nmol/l

Question 15

What ACTH and cortisol results signify primary AI?

Answer 15

• ACTH > 22 pmol/l
• Elevated renin

Question 16

What ACTH result signifies secondary AI?

Answer 16

ACTH < 5 pmol/l

Question 17

What are causes of primary AI?

Answer 17

• Adrenal antibodies
• Very long chain fatty acids
• Genetic

Question 18

What are causes of secondary AI?

Answer 18

• Any steroids?
• Imaging
• Genetic

Question 19

What is the goal of treatmen of AI?

Answer 19

mirror the normal physiological state

Question 20

How do you treat AI?

Answer 20

• Replace aldosterone with fludrocortisone (primary AI)
• Hydrocortisone 2/3 times daily

Question 21

What happens in adrenal crisis?

Answer 21

• Hypotension and cardiovascular collapse
• Fatigue
• Fever
• Hypoglycaemia
• Hyponatraemia and hyperkalaemia