Pathophysiology of Pituitary & Adrenal Disorders Flashcards
What is the gold standard test for diagnosing hypercortisolism?
24-hour urinary free cortisol level
What is the most common cause of Cushing syndrome?
Exogenous administration of glucocorticoids
Bilateral renal bruits is most associated with what hyperaldosteronism?
Secondary hyperaldosteronism with high BP
What is the safest test to diagnose GH deficiency?
Arginine infusion test (this test, however, is not the best test)
Growth failure, hypoglycemic episodes, and adiposity are associated with this pituitary disorder.
Growth hormone hyposecretion
What is Addison’s disease?
Primary hypocortisolism due to destruction of the adrenal gland
Hypersecretion of growth hormone is associated with what disorders?
Gigantism & acromegaly
What is the most common cause of death in patients with gigantism and acromegaly?
Congestive heart failure due to cardiomegaly
This disorder is characterized by ischemia necrosis of the pituitary gland in postpartum women.
Sheehan Syndrome
What is the best test to diagnose GH deficiency?
Insulin-induced hypoglycemia (this test, however, is not the safest)
What is pituitary apoplexy?
Acute hemorrhage into a preexisting pituitary adenoma causing sudden and severe headache, CN paralysis, vision defects, hypotension, and CV collapse
What hormone is most commonly released by pituitary adenomas?
Proalctin
ACTH plays only a minor role in aldosterone release. What other molecules play an important role in release of aldosterone?
K+ & Angiotensin II
True/False. Most cases of gigantism and acromegaly are due to a benign pituitary macroadenoma.
True
From what adrenal zone is aldosterone released?
Zona glomgerulosa
A patient is referred for refractory hypertension and hypokalemia. No edema is present. Their plasma aldosterone activity:plasma renin activity ratio is 25. What is the diagnosis?
Primary aldosteronism - PAA: PRA > 20
What is the first-line treatment for hyperprolactinemia?
Dopamine agnost medications
What is the difference between primary and secondary hyperaldosteronism?
Primary is due to an intrinsic defect in the pituitary (ex: adenoma, hyperplasia).
Secondary is response to some other chronic stimuli (renal artery stenosis, liver cirrhosis, heart failure)
What unique clinical finding is only found with Addison’s disease and not secondary hypocortisolism?
Skin hyperpigmentation - due to increased ACTH that stimulates melanocytes
What is the difference between gigantism & acromegaly?
Gigantism is due to GH hypersecretion before puberty and proportional longitudinal growth.
Acromegaly is associated with GH hypersecretion after puberty, with no linear growth.
In cases of primary hyperaldosteronism, there is only slight hypernatremia and increased ECF. Why is this?
Aldosterone escape phenomenon - although aldosterone increases Na+ retention by the kidneys, the increase in ECF volume stimulates release of natriuretic peptides that increases Na+ excretion
What is the confirmatory test for GH hypersecrection?
Oral Glucose Tolerance Test (OGTT)
What symptoms are associated with hyperprolactinemia?
Galactorrhea, amenorrhea, decreased libido, infertility, osteoporosis
What is Laron Syndrome?
Autosomal recessive disorder characterized by resistance to GH, increased GH secretion, and decreased insulin growth factor (IGF)
