Adrenal Disease Flashcards
What hormones are produced by the adrenal cortex?
ZG: Mineralcorticoid, Aldosterone
ZF: Cortisol and Androgens
ZR: Under constant ACTH control “basal” secretion of cortisol (always some there just in case)
What is produced by the adrenal medulla?
Catecholamines: Epinephrine, Norepinephrine, Dopamine
These aren’t subject to hypothalamus action-required to act quickly
What do Mineralocorticoids stimulate?
Aldosterone stimulates sodium reabsorption = water retention and potassium excretion.
What are androgens excreted by the adrenal cortex precursors for?
testosterone and estrogen
What are adrenal medulla hormones responsible for?
catecholamines are responsible for fight or flight, sympathetic NS response. These are not under pituitary control, controlled by sympathetic NS via direct neural stim. Types:
- norepinephrine
- epinephrine
- dopamine
Where is cortisol produced and what is it’s function?
Adrenal cortex
functions as another stress hormone.
receptors (glucocorticoid) are found in virtually all tissue functions as:
Stress response
Glucose metabolism (increases gluconeogenesis)
Regulates metabolism of proteins and fats
calcium homeostasis
suppresses immune response
Maintains circadian rhythm
peripheral vasc. tone
increases cardiac output
Diurnal excretion of cortisol?
cortisol is at it’s highest at 6:00am (when melatonin is lowest)
Cortisol is at it’s lowest at 12:00am (when melatonin is at it’s highest)
When is cortisol secreted?
Exercise and stress-increases C.O
Vascular tone-Increases Periph. resistance
Acute Trauma-regulates inflammation
What can occur if cortisol is given in excess or used chronically?
HTN Peptic ulcer Decreased estrogen/testosterone increased appetite Decreased cognitive fxn. euphoria depression irritability Decreased immune response
Define Acute Adrenal insufficiency
Emergency caused by insufficient cortisol
Rapid tx is essential to save life (cardiac collapse)
What are the 2 types of adrenal insufficiency?
Primary (adrenal insufficiency)-adrenal failure to produce cortisol
Secondary (Pituitary insufficiency) -pituitary failure to produce sufficient ACTH
What is the MC cause of acute adrenal insufficiency?
Abrupt discontinuation of adrenocortical (prednisone)
What are possible triggers of latent adrenal insufficiency?
Stress Removal of hypercortisol secreting adrenal tumor w/suppression of other adrenal gland Pituitary necrosis Trauma Adrenal hemorrhage Anticoagulant (warfarin)
Clinical findings of Acute adrenal insufficiency
GI-abd pain/diarrhea, salt craving (mc in chronic)
Psych/neuro-HA, Confusion, coma/cerebral edema
Systemic-weakness, fever
CV-hypotension
Skin-hyperpig
Endocrine-Hypoglycemia
Lytes-hyponatremia, hyperkalemia,
Lab findings of Acute adrenal insufficiency
Low cortisol, and high ACTH, low aldosterone - dehydration and volume contraction
diagnostic tests for Acute adrenal insufficiency
-Co-synthropin ACTH stim test: After IM injection of co-synthropin, cortisol levels measured at 30 and 60,
Normal-~20mcg/dL
Abnormal (adrenal insuff)- < 20 mcg/dL because ACTH fails to tim adrenal glands.
-ACTH will also be very high because there is little or no negative feedback
ddx for acute adrenal insufficiency
Shock
Hyperkalemia
hyponatremia
tx for acute adrenal insufficiency
High index of suspicion-treat immediately!!!
Hydrocortisone (1st line)
Continuous IV saline 5% dextrose restore plasma volumen and hypoglycemia
tx infections empirically (don’t wait for cultures)
Rapid tx is essential and life saving!!!
What is the most common cause of chronic adrenal insufficiency in the US?
Addison’s disease
What are the causes of chronic adrenal insufficiency
Addison's dz: autoimmune (idiopathic) - distraction of adrenal cortex Infection-TB in developing nations Fungal Chronic use of steroids-blunting of ACTH/CRH response Metastatic ca. HIV Iatrogenic (ketoconazole, steroids) women>men 30-60yo
t/f Addisons disease is characterized by HIGH ACTH and LOW glucocorticoid (cortisol)
T!
signs and symptoms of chronic adrenocortical insufficiency
Intolerance to physical stress
constitutional sx-weakness, fatigue, low grade fever
skin-hyperpigmentation, creases
GI-anorexia, weight loss, abd. pain, Anorexia n/v, SALT craving, signs of dehydration
CV-Hypotension, orthostatic hypotension, shock, small heart
MSK-myalgias arthralgias
Neuro-delayed DTR’s, anxiety irritability
Psych-lethargy, confusion, psychosis
diagnostics for chronic adrenocortical insufficiency
hpoglycemia
plasma ACTH elevated
Low serum sodium
Elevated potassium
Low plasma cortisol @8am w/ elevated plasma ACTH
antibodies for autoimmune dz
Co-synthropin (ACTH) stim test-failed adrenal response
tx of chronic adrenocortical insufficiency
Replacement of glucocorticoids and mineralocorticoids
- hydrocortison/prednisone-lowest effective dose to avoid Cushingoid s.e., increase dose at times of illness
- Fludrocortison (aldosterone)-If there is hyponatremia, hypokalemia, dehydration, postural hypotension
Medical alert bracelet
What disease is caused by adrenal excess?
Cushing’s dz.
What is the cause of Cushing’s dz?
MC cause- Iatrogenic-chronic exposure to exogenous glucocorticoid such as prednisone
Adrenocortical tumors
non-pituitary ACTH secreting tumors (SCLCA)
Ectopic CRH
What is the difference between Cushing’s dz and Cushing’s Syndrome?
Cushing disease refers to the excess pituitary secretion of ACTH (usually by a benign adenoma).
Cushing’s Sydrome is a subset of Cushing’s dz (40-70%) and is due to the hyercortisolism caused by either Cushing’s dz, or Adrenocortical tumors
What are the two subcategories for Cushing’s syndrome?
- ACTH dependendend hypercortisolim: Cushing’s Dz, non-pituitary secreting tumor, ectopic CRH
- ACTH independent hypercortisolism: adrenocortical tumors
signs and sx of Cushing’s syndrome:
- Body fat maldistribution: Central obesity (90%), moon face, buffalo hump, Supraclavicular fat pads, thin extremities,
- CV effects: HTN (85%)
-Endocrine effects: Decresed Glucose Tolerance (80%)
menstrual irregularity and infertility
masculinization in females (in ACTH dep.)-Hirsutism, virilzaiton, Hypogonadism in men and women
- Const: Weakness
- Lytes: K+excretion, Na+retention, CA++ loss
- Immune: Immnosuppression
- MSK: Prox muscle wasting, osteoporosis, aseptic necrosis of femoral head
- Skin-purple straiae
INITIAL labs diagnosis Cushing’s
24 hr urine free cortisol: 3 separate collections to dx Cushing’s
Late night salivary cortisol level (should be low at mid-night)
Low dose Dexamethasone (cortisol) suppression test:
- Dexa 1mg at 1pm-check cortisol at 8am
- Cortisol s because there was NO suppression with dexamethasone (further testing needs to be done to determine if CS or CD)
FOLLOW UP labs and diagnosis of Cushing’s
High dose Dexa supression test.
Dexa 8mg at 11pm-check cortisol at 8am next day
Cushing’s disease (pituitary)
-level will result in >50% drop in cortisol baseline
NOT Cushing’s disease
-No or very mild cortisol suppression and cortisol and ACTH remain high (Ectopic ACTH tumor
ACTH must be measured after abnormal DEXA suppression test
imaging for hypercortisolim (CS/CD)
Chest CT
Abdominal CT
Pituitary MRI
DDX for Hypercortisolim
Alcoholism
pregnancy
Depression
Severe obesity
tx of hypercortisolim
If caused by long term use of glucorticoid dosage is gradually reduced
Adrenal adenoma: adrenalectomy w/ prednisone replacement until other adrenal gland can take over
pituitary ademona: surgical resection / steroid replacement until pituitary recovers.
What is 1st line for pituitary ademona tx?
Transsphenoidal surgery (newer technique q/ sterotactic radiosurgery or gamma knife)
Complications of Cushings:
Visual field impairment
Death - d/t HTM, Diabetes, Infection
Osteoprosis, nephrolithiasis, psychosis
