Normal adrenal function and adrenal disease

Question 1

What is stress

Answer 1

State of threatened homeostasis or dysharmony

Question 2

How does the body respond to stress

Answer 2

Increased CV tone, ventilation

Increased glucose availability

decreased energy-consuming activities such as digestion and reproduction

Question 3

Behavioural mechanisms as a response to stress

Answer 3

Increased;
arousal
alertness
Vigilance

Question 4

What is the integrated stress response

Answer 4

SNS and adrenaline

CRH-ACTH-Cortisol

Question 5

What hormones are stimulated under acute stress situations and which are inhibited

Answer 5

RAAs, ADH, GH (growth hormone), decreased thyroid hormones

Question 6

Why is it important for cortisol to have an anti-inflammatory/immunosuppressive effect

Answer 6

IN stress-activated immune responses, cortisol protects the body against damage from potential over-activation of immune defence mechanisms

Question 7

Prolonged elevated cortisol levels can lead to what

Answer 7

• Muscle wasting
• Hyperglycaemia
• GI ulcers (increased susceptibility)
• Impaired immune response

Question 8

What disease causes glucocorticoid excess exogenous cause

Answer 8

Cushing’s syndrome

Can be endogenous (natural) or exogenous (causes by steroid medication)

Question 9

What disease causes mineralocorticoid excess

Answer 9

Conn’s syndrome

Question 10

What disease causes adrenal insufficiency

Answer 10

Addison’s disease

Question 11

What are endogenous (natural causes) of Cushing’s syndrome

Answer 11

Primary-
-Adrenal (carcinoma, adenoma)

Secondary-

• PItuitary
• Ectopic

Question 12

What are the levels of ACtH and cortisol in those with primary and secondary causes of Cushing’s

Answer 12

(P) Adrenal- Low ACTH, high cortisol

(S)Pituitary - high ACTH, high cortisol

(S) Ectopic- high ACTH, high cortisol

Question 13

Difference between Cushing’s disease and Cushing’s syndrome

Answer 13

Cushing’s syndrome- umbrella term

Cushing’s disease- due to a pituitary ACTH secreting tumour

Question 14

What is Cushing’s disease and what is the negative feedback loop like

Answer 14

Excessive production of ACTH. ACTH levels remain high as the tumour cells have impaired responsiveness to negative feedback from high cortisol levels

Question 15

What causes acne, female frontal balding, female hirsutism and menstrual irregularities in Cushing’s patients

Answer 15

Excess production of adrenal androgens

Question 16

What causes testicular atrophy, thin arms and less, muscle weakness, thin skin and purple striae (stretch marks) in Cushing’s patients

Answer 16

Breakdown of protein, muscle wasting, loss of collagen

Question 17

What causes poor wound healing, easy bruising and infections of the skin in Cushing’s patients

Answer 17

Loss of collagen, immunosuppression

Question 18

What other complications may arise from Cushing’s and why

Answer 18

Osteoporosis - altered bone metabolism

Hypertension- excess mineralocorticoid activity (sodium retention and hypokalaemia)

Diabetes- Hyperglycaemia, insulin resistance

Question 19

What can excess glucocorticoids in childhood lead to

Answer 19

Growth retardation

Question 20

How to diagnose Cushing’s

Answer 20

First confirm levels of high cortisol

Then look at ACTH levels to find out the cause

Then dynamic tests (Low-dose DEX test, high-dose DEX test and CRH test)

Question 21

How is diurnal rhythm like in Cushing’s patient

Answer 21

There is a loss of diurnal rhythm of cortisol release. In a normal test, cortisol levels would be high in the morning and very low in the evening (at midnight). But in a Cushing’s patient, they remain high throughout the day

Question 22

What can ACTH levels tell you about Cushing’s

Answer 22

Whether it is a primary or secondary cause

IN primary-low ACTH
Secondary- High ACTH

Question 23

What is a low dose DEX test

Answer 23

Dexamethasone is a synthetic glucocorticoid

Dexamethasone suppression test:
Lack of suppression indicates hyper-autonomous secretion which confirms Cushing’s

Question 24

What is a high dose DEX test and what does it tell you

Answer 24

There is normally suppression.

NO suppression when the cause is adrenal and an ectopic ACTH tumour

Suppression when the cause is Cushing’s disease (pituitary)

Question 25

What is the CRH stimulation test used to see.

What are the results like in a normal patient and a Cushing’s patient

Answer 25

Used to distinguish between pituitary-dependent Cushing’s and an ectopic source of ACTH.

Normally there is a rise in both ACTH and cortisol.

IN pituitary-dependent Cushing’s patients, the response is exaggerated

IN ectopic ACTH syndrome, there will be no response to CRH

Question 26

How to locate tumours of:

• Anterior pituitary
• adrenal
• Bronchial tumours
• ACTH-secreting tumours

Answer 26

Ant- pituitary- MRI
Adrenal- Abdominal CT/MRI
Bronchial- Chest xray
ACTH secreting tumours- Octreoscan

Question 27

What are the treatments of Cushing’s

Answer 27

Surgery or radiotherapy

Medical drugs to inhibit steroidogenesis (pre-operative or palliative)

Question 28

When are the drugs for Cushing’s used and what are the drugs

Answer 28

PRe-operative
Palliative (rarely used for long-term therapy)

Metyrapone and trilostane

Question 29

What is the mode of action metyrapone

Answer 29

Inhibits adrenal steroidogenesis