Cushing's Disease/syndrome

Question 1

What hormone is involved in Cushing’s disease?

Answer 1

Excess cortisol (glucocorticoid), released at the adrenal gland. 
Is stimulated by ATCH (adrenocorticotrophic hormone)

Question 2

Describe the difference between primary and secondary disease?

Answer 2

Primary cushing’s is when the problem is within the adrenal gland itself. (this is referred to as Cushing’s syndrome)

Secondary - cushbing’s with a cause outside the adrenal gland. This will have high ATCH levels as well as high cortisol levels, as it is the increased stimulation by the elevated ATCH that is causing the high cortisol levels. This is called ATCH dependant/ Cushing’s disease. Can be a pituitary gland (anterior) problem or an ectopic ATCH producing tumour.

Question 3

Symptoms and signs

Answer 3

Moon face, pink striae, central obesity, thin skin, muscle wasting and thinner arms and legs, buffalo hump.

hypertension
Raised BG/diabetes

Question 4

Tests

Answer 4

24hr cortisol levels can be done as screening
Low dex test is done to confirm
Morn-midnight ACTH cortisol levels testing is done to determine if primary or secondary cause
High dex test is done if secondary to determine if pituitary or ectopic problem.

Question 5

Treatment for Cushing’s

Answer 5

Surgery to remove causative tumour

or if surgery not possible:
Adrenal hormone synthesis inhibitors (e.g. metyrapone)
Mitotane is used to destroy adrenocorticol cells
Radiotherapy
Bilateral adrenalectomy

Question 6

What is the primary to secondary splint? Who is most affected?

Answer 6

80% secondary/ATCH dependant
20% primary/ATCH independant
Mainly affects women

Question 7

When is peak ACTH release?

Answer 7

Early morning (6-9am)
Lowest at midnight
Cortisol follow same pattern but bursts last for a little longer.

Question 8

What is the Adrenal Hormone synthesis inhibitor used to treat Cushing’s?

Answer 8

MeTYRApone