Lecture 7.2 - Adrenal disorders

Study Notes

Cushing's disease is a specific case of a benign ACTH secreting pituitary adenoma
Cushing's syndrome is a general constellation of symptoms resulting from chronic exposure to increased cortisol levels
Cushing's syndrome is more common than Cushing's disease
Most commonly secondary to long-term treatment with glucocorticoids

Caused by long-term treatment with glucocorticoid drugs (e.g. hydrocortisone, prednisone, prednisolone, dexamethasone)
Used to treat inflammatory disorders, autoimmune conditions, and to suppress immune reaction to organ transplantation
Glucocorticoids have anti-inflammatory and immunomodulatory effects
Side effects of glucocorticoids are similar to the effects of higher cortisol levels
Can also have mineralocorticoid effects (bind to the mineralocorticoid receptor)
Important: Glucocorticoids should not be stopped suddenly, dosage should be reduced gradually

Thin arms and legs with muscle weakness due to increased muscle proteolysis
Weight gain and deposition of fat in abdomen, neck, and face
Purple and wide striae on lower abdomen, upper arms, and thighs
"Steroid diabetes" - secondary diabetes due to increased hepatic gluconeogenesis and muscle proteolysis
Increased susceptibility to bacterial infections, poor wound healing, and acne
Osteoporosis caused by calcium metabolism disturbances and loss of bone matrix protein
Hypertension due to sodium and fluid retention caused by mineralocorticoid effects
Psychologic symptoms - mental changes, depression
Hypogonadism, menstrual disorders in women, hirsutism, and baldness

Cushing's syndrome mortality is >50% if not treated
Death usually results from severe infection
Growth ceases in children with Cushing's syndrome if not treated before epiphyses of the bones have sealed
Clinical diagnosis, biochemical diagnosis, and radiological diagnosis to localise the problem
Golden rule: clinical diagnosis, biochemical diagnosis, and radiological diagnosis