Endocrine Function III Part 2 Flashcards
Addison’s disease
-clinical symptoms due to mineralcorticoid deficiency
Dehydration, hypotension, hyperkalemia, metabolic acidosis, hyponatremia
Addison’s disease
-clinical symptoms due to glucocorticoid deficiency
Fatigue, weakness, weight loss, GI disturbances, post parandial hypoglycemiaz
Addison’s disease
-reason for hyperpigmentation and infertility
No negative feedback on anterior pituitary (ex hyperpigmentation not present because ACTH excess is not present to stimulate MSH production)
Addison’s disease
-typical Na, K, blood sugar, cortisol, and ACTH lab results
Increased ACTH, decreased cortisol, decreased blood sugar, decreased sodium, and increased potassium
Cause of addisonian crisis?
During infection or acute stress, Addison’s patient cannot respond with increased aldosterone and cortisol and can go into shock with hypotension, fever, hypovolemia, and hyperkalemia (life threatening)
What is the cause of Waterhouse-Friderichsen?
Caused by meningococcal meningitis and septicemia; this causes acute adrenal insufficiency
What is the most common cause of tertiary adrenal insufficiency ?
Chronic pharmacological administration of glucocorticoids
What are four conditions associated with a hyperfunctioning adrenal cortex?
1 primary aldosteronism (Conn’s Syndrome)
2 secondary aldosteronism
3 cushing’s syndrome
4 Congenital adrenal hyperplasia
Primary Aldosteronism (Conn's Syndrome) -cause
Adenoma in outermost layer (tumors)
Primary Aldosteronism (Conn's Syndrome) -outstanding clinical symptom
Hypertension
Primary Aldosteronism (Conn's Syndrome) -typical serum and urine K,Na,aldosterone, and renin levels
Decreased Potassium, increased sodium, increased aldosterone, decreased renin, increased urine potassium, metabolic alkalosis caused by increased H secretion in urine (caused by increased Na reabsorption)
What are two general causes in secondary aldosteronism?
1 decreased blood flow to kidney causing decreased GFR
2 hyperactivity of RAAS causing increase in renin production
Cushing’s Syndrome
-five clinical symptoms
Moon face, buffalo hump, truncal obesity, purple striae, hypertension
Cushing’s Syndrome
-three general causes
Exogenous glucocorticoid therapy (prednisone), ACTH-dependent syndrome, ACTH-independent
Cushing’s syndrome
-two specific causes of ACTH-dependent cushing’s
Cushing’s, Ectopic ACTH secreting tumors
Cushing’s Syndrome
-Two specific causes of ACTH-independent cushing’s
Adrenal adenoma, nodular adrenal hyperplasia
Cushing’s syndrome
-two recommended screening tests and typical results if patient has syndrome
- 24 hr free cortisol (>120=cushing’s)
- overnight dexamethasone suppression test
- AM/PM cortisol levels
Cushing’s syndrome
-expected morning and afternoon cortisol levels
Increased in AM, decreases over the day normally (cushing’s is increased all the time)
Cushing’s syndrome
-typical sodium, potassium, blood sugar, cortisol
Increased Na, decreased K, increased blood sugar, and increased cortisol
Cushing’s syndrome
-typical ACTH results in Cushing’s syndrome, cushing’s disease, and ectopic ACTH secreting tumors
Increased ACTH due to the adrenal cortex being stimulated
Congenital adrenal hyperplasia (CAH) (adrenogenital syndrome)
-pathogenesis
Caused by enzyme deficiencies in the pathways to produce the glucocorticoids and mineralocorticoids; no negative feedback since cortisol not produced and aldosterone is decreased
Congenital adrenal hyperplasia (CAH) (adrenogenital syndrome)
-two common enzyme deficiencies
21-hydroxylase and 11-beta-hydroxylase
Congenital adrenal hyperplasia (CAH) (adrenogenital syndrome)
-expected cortisol, ACTH, progesterone, DHEA, sodium, and potassium levels
Decreased cortisol, increased ACTH, increased progesterone, increased DHEA, decreased sodium, and increased potassium
Congenital adrenal hyperplasia (CAH) (adrenogenital syndrome)
-typical symptoms in boys and girls
Females: abnormalities of external genitalia at birth (cannot tell if male or female); hirsutism, infertility, breast atrophy
Males: appear normal at birth, but have sexual precocity (too much testosterone)
Both: acne, coarsening of voice, scalp recession early in life
Both:
Congenital adrenal hyperplasia (CAH) (adrenogenital syndrome)
-lab test included in newborn screen to check for this condition
17-hydroxyprogesterone
This is an enzyme kinetic assay used to measure angiotensin I produced from angiotensinogen by renin
Plasma renin activity test (PRA)
Stimulation tests are used to assess _________ hormonal states. (Hypo or hyperfunctioning)
Hypofunctioning
Suppression tests are used to assess _______ hormonal states (hypo or hyper)
Hyperfunctioning
ACTH stimulation test
-diagnostic use
Differentiate primary adrenal insufficiency (Addison’s) from secondary (hypopituitarism)
ACTH stimulation test
-analyte measured
Cortisol
ACTH stimulation test
-expected normal response
Serum cortisol should double in 30 minutes
ACTH stimulation test
-results in Addison’s disease
Little or no change in cortisol levels
ACTH stimulation test
-results in hypopituitarism
Increased levels of cortisol on successive days (2-3) of ACTH stimulation (delayed or “staircase” response)
Metyrapone Test
-principle
Selectively inhibits 11-beta-hydroxylase, so the conversion of 11-deoxycortisol to cortisol is inhibited, allowing unrestricted release of ACTH
Metyrapone Test
-diagnostic use
Differentiation of normal patients from secondary adrenal insufficiency (hypopituitarism); assesses pituitary ACTH reserve; basically to see how much ACTH the patient can produce)
Metyrapone Test
-expected normal response
Decreased cortisol, increased 11-deoxycortisol, and increased ACTH
Metyrapone Test
-results in hypopituitarism
Unchanged cortisol, 11-deoxycortisol, and ACTH levels
