Cushings Syndrome Flashcards
what is cushings disease?
pituitary adenoma releasing excess ACTH
what is cortisol bound to?
cortisol binding globulin, 5% unbound which is biologically active
cortisol causes?
gluconeogenesis
proteolyis
lipolysis
increases sensitivity of peripheral blood vessels to catecholamines
it reduced release of inflammatory mediators
inhibits t lymphocyte proliferation
elevated cortisol causes?
severe muscles, bone and skin breakdown
high glucose levels and so high insulin levels- activates lipoprotein lipase- accumulate more fat cells,
hypertension,
inhibits gonadotrophin releasing hormone - ocarian/testicular fucntion
dampen immune system
Symptoms of cushings?
muscle wasting/ thin extremities
abdominal striae
fractures osteoporosis
round full moon face
buffalo hump
truncal obesity
easy bruising
DM, HTN poor wound healing, vulnerability to infections
amenorrhoea
diagnosis of cushings?
measuring free cortisol 24 hour urine sample,
blood/saliva late at night
dexamethasone suppression test suppresses ACTH
after youve discovered cortisol levels are high what should you do?
low ACTH- adrenal adenoma/ carcinoma
high ACTH- cushings disease, ectopic ACTH production
then dexamethsone injection, ectopic sites wont respond
imaging in cushings
MRI pituitary, CT of adrenals, chest abdomen pelvis
treatment of cushings?
decrease exogenous steroids
surgical excision
adrenal steroid inhibitors- ketoconazole plus metyrapone
for ectopic ACTH or adrenal carcinoma
ACTH independent causes?
iatrogenic: steroids
adrenal adenoma (5-10%)
adrenal carcinoma (rare)
Carney complex: syndrome including cardiac myxoma/ skin pigmentation
micronodular adrenal dysplasia (very rare)
what is pseudo cushings?
excess alcohol or depression causes it
how to differentiate pseudochings?
insulin stress test
ectopic ACTH secretion is normally associated with?
low potassium levels
what is usually seen in cushings syndrome?
hypokalaemic metabolic alkalosis
first line test for cushings?
overnight dexamethsaone suppression test
