Endo 6 - Hyperadrenal Disorders Flashcards
(47 cards)
Describe the effects of excess cortisol on protein and fat synthesis
decreased protein synthesis
increased fat synthesis
Explain why people with Cushing’s get stretch marks?
Putting on fat very quickly which stretches the skin
protein cannot be synthesised quick enough to replace skin tears
Describe the clinical features of Cushing’s syndrome?
- Moon face
- interscapular fat pad
- proximal myopathy
- easy bruising
- striae
- thin skin
- osteoporosis
- diabetes
- centripetal obesity
- hypertension and hypokalaemia
What hormone is in excess in Cushing’s?
Cortisol
Why is there bruising in Cushings?
cannot synthesise protein to heal
What is proximal myopathy?
weakness of limbs - usually lower limbs
Why do you get hypertension and hypokalaemia?
cortisol binds to receptors on kidney to retain sodium and excrete potassium
What is the difference between Cushing’s syndrome and disease?
Disease = pituitary tumour Syndrome = other causes e.g. ectopic lung tumour
Name 4 causes of Cushing’s syndrome?
Pituitary adenoma
Ectopic ACTH releasing tumour e.g. lung
Oral glucocorticoid drugs
Adrenal adenoma
Name 3 tests used to diagnose Cushings
- 24 hour urine free cortisol
- Diurnal blood cortisol level
- Low dose dexamethasone suppression
Explain the 24 hour urine free cortisol test
normal people will have high cortisol in the morning and then will go down
People with Cushing’s will have high even in the night
Explain Diurnal blood cortisol level
Admit patient, and connect catheter and take a midnight reading of cortisol while the patient is sleeping
normal = low cortisol
cushings = high cortisol
Why do you do a diurnal blood cortisol level test while the patient is sleeping?
stress of blood test may increase the cortisol
Explain the Low dose dexamethasone suppression test?
artificial steroid which will usually cause a suppression of cortisol
normal = low cortisol
cushings = high cortisol
What is the test to differentiate between Cushing’s disease and Cushing’s syndrome?
High dose dexamethasone test
disease = low cortisol as will be inhibited in pituitary
syndrome = still high
What are the two surgeries for cushing’s syndrome?
If disease = transphenoidal hypophysectomy
if syndrome = bilateral adrenalectomy
State 2 drugs used to treat Cushing’s before surgery?
Metyrapone + Ketoconazole
Which enzyme is inhibited by metyrapone?
11-hydroxylase
How does metyrapone work?
prevents the conversion of 11-deoxycortisol to cortisol so less cortisol
Why is this given to patients before surgery?
As too much cortisol = hypertensive so need to control that before surgery
What hormone accumulates with the use of metyrapone?
11-deoxycorticosterone and 11 deoxycortisol
11-deoxycortisosterone has mineralcorticoid properties
which causes sodium retention and potassium excretion - hypertensive
also hormones funnelled towards sex steroids so causes hirsuitism in women
Is metyrapone good for short term or long term?
Short term only to prepare for surgery
What class of drug is ketoconazole?
Anti-fungal
Why was it withdrawn in 2013?
Hepatotoxicity
