The Adrenal Gland Flashcards
Short term stress results in release of _________ from the adrenals, while long term stress results in _____ and _____ release from the adrenals
Catecholamines; mineralocorticoids; glucocorticoids
Layers of adrenal cortex and their hormones
Glomerulosa — mineralocorticoids
Fasciculata — glucocorticoids
Reticularis — sex steroids
What hormones are elevated in 21-hydroxylase deficiency?
DHEA
Androstenedione
Testosterone
Treatment for 21-hydroxylase deficiency
Hydrocortisone
Fluids/glucose
Get K+ level down
T/F: congenital adrenal hyperplasia is one of the disorders included in newborn screening
True
Most common cause of primary adrenal insufficiency (addison) in the US
Autoimmune
2nd most common cause is TB
Cause of primary adrenal insufficiency that involves bilateral hemorrhage of the adrenals
Waterhouse-Friderichsen syndrome
Describe inheritance and presentation of familial glucocorticoid deficiency
Autosomal Recessive
Inherited adrenal unresponsiveness to ACTH —> increase in ACTH results in skin pigmentation
Most common type of congenital adrenal hyperplasia
21-hydroxylase deficiency
Presents with salt wasting (aldosterone deficiency), deficiency of cortisol, virilization in females (excess androgens)
Clinical signs/symptoms of primary adrenal insufficiency
Nearly all pts complain of fatigue, reduced stamina, weakness, anorexia, weight loss, and skin hyperpigmentation
Some pts may complain of abd pain, N/V, MSK pain, psychiatric sxs, HA, gait disturbance, salt craving, orthostatic light headedness, virilization in females
Lab findings in primary adrenal insufficiency
Low serum Na
High serum K+
Fasting hypoglycemia
Hypercalcemia
LOW 8AM PLASMA CORTISOL + SIGNIFICANT ELEVATION OF PLASMA ACTH
What test is used to confirm primary adrenal insufficiency?
Cosyntropin (synthetic ACTH) stimulation test
If cortisol levels do not respond to cosyntropin, primary adrenal insufficiency is confirmed
How is a dx of autoimmune addison disease confirmed?
Serum Abs to 21-hydroxylase
In 21-hydroxylase deficiency, elevated serum levels of ______ are required for dx
17-OH-progesterone
Treatment for primary adrenal insufficiency
Glucocorticoid replacement therapy
Mineralocorticoid replacement therapy
DHEA — given to some postmenopausal women
Low serum ACTH in the setting of low serum cortisol indicates __________
Secondary adrenal insufficiency
Cushing disease is considered ACTH-_______ Cushing syndrome
Exogenous corticosteroid use, adrenocortical tumor, and McCune Albright syndrome are examples of ACTH-_______ Cushing syndrome
Dependent
Independent
Describe the Dexamethasone suppression test for Cushing syndrome
Low dose dexamethasone given at night, serum cortisol drawn in the morning
If the serum cortisol is below a certain level, Cushing syndrome is excluded with some certainty. Result is then used in conjunction with ACTH levels (drawn before dexamethasone is given) to determine the cause of the hypercortisolism
Results of dexamethasone suppression test that indicate ectopic ACTH syndrome
Elevated ACTH and cortisol is not suppressed by high or low doses
What do most pts with primary hyperaldosteronism present with?
Hypertension
Metabolic alkalosis (proton loss, H+ with K+)
[may see hypokalemia in 37%]
What is Conn syndrome
Primary aldosteronism secondary to a unilateral aldosterone-producing adrenal adenoma
40% have a mutation in a gene coding for the K+ channel
What disease is associated with 20% developing pheochromocytomas (NE-secreting), hemangiomas, hyperthyroidism, pancreatic cysts, endolymphatic sac tumors, cystadenomas of adnexa or epididymis, pancreatic neuroendocrine tumors, renal cysts, adenomas, and carcinomas?
Von Hippel-Lindau disease type 2 (autosomal dominant)
Lab findings in pheochromocytoma
Plasma fractionated free metanephrins is the single most sensitive test for secretory pheochromocytomas and paragangliomas
Medical treatment prior to resection of pheochromocytomas
Alpha-blockers — Phenoxybenzamine is a long acting nonselective alpha blocker
Also give Ca-channel blockers, and beta-blocker (usually metoprolol)
Inheritence and significance of MEN syndromes
Autosomal dominant
Cause a predisposition to the development of tumors in 2+ endocrine glands; MEN 2 and 3 both associated with pheochromocytomas
