02a: Adrenal Insufficiency, Cushing's Flashcards
Cortisol metabolic actions: (raises/lowers) blood glucose by stimulating which processes?
Raises;
Gluconeogenesis, lipolysis, protein catabolism
Cortisol’s has effects on metabolism as well as which other physiological systems?
Circulatory (pressor effects) and immune (anti-inflamm)
List the regulators of aldosterone secretion.
- RAAS (A-II)
- K
- ACTH (less important)
T/F: Cortisol secretion only controlled by ACTH
True
Addison’s disease is (X) (excess/insufficiency).
X = primary adrenal
Insufficiency
The difference between primary and secondary adrenal insufficiency is level of (X) hormone(s).
X = aldosterone and androgens (will be OK in secondary disease since ACTH is not only regulator for these)
T/F: Cortisol levels are high in both primary and secondary adrenal insufficiency.
False - LOW in both
List the symptoms of glucocorticoid (excess/deficiency) in Addison’s
Deficiency
Weight loss, nausea, fatigue, weakness, hypoglycemia
List the symptoms of mineralocorticoid (excess/deficiency) in Addison’s
Deficiency
Postural hypotension, hyperkalemia, hyponatremia
List the symptoms of ACTH (excess/deficiency) in Addison’s
Excess
Hyperpigmentation
Both ACTH and (X) are cleaved from (Y) precursor protein. This explains which symptom in high ACTH state?
X = MSH (melanocyte stim hormone) Y = POMC
Hyperpig
List some infectious causes for primary adrenal insufficiency.
- TB
- HIV/AIDS
- Systemic fungal
Tapering off steroids is crucial because sudden withdrawal can cause (X) (excess/deficiency).
X = secondary adrenal insufficiency (lack of ACTH stimulus)
You suspect adrenal insufficiency in patient. Which test(s) do you order?
Rapid Cortrosyn (ACTH) test (250 mcg ACTV IV)
Rapid Cortrosyn test for adrenal insufficiency: (X) administered and which values measured?
X = ACTH (i.v.)
- ACTH at level 0
- Cortisol and aldosterone at 0, 30, 60 min
Rapid Cortrosyn (ACTH) test: expected levels/response in normal patient…
- Cortisol and aldosterone increase
2. ACTH in normal range
Rapid Cortrosyn (ACTH) test: expected levels/response in Addison’s patient…
- Cortisol and aldosterone low
2. ACTH super high
Rapid Cortrosyn (ACTH) test: expected levels/response in secondary adrenal insufficiency patient…
- Cortisol low (gland atrophy due to low ACTH); aldosterone normal
- ACTH low *** key to distinguish from primary disease
Adrenal insufficiency medication:
- Glucocorticoid replacement (hydrocortisone/cortisone/prednisone)
- Synthetic aldosterone (Florinef)
- Maybe Androgen replacement for women?
Adrenal insufficiency: patients must be educated about…
- Steroid ID alert bracelet
2. Increase dose of meds if sick
Most common cause of Cushing’s Syndrome:
High-dose steroid use
(X)% of Cushing Syndrome is ACTH-dependent causes, such as:
X = 80
- ACTH pituitary tumor (CUSHING DISEASE)
- Ectopic ACTH (tumor)
- CRH production (tumor, RARE)
(X)% of Cushing syndrome is due to primary adrenal excess, caused by:
X = 20
- Adrenal adenoma
- Adrenal carcinoma (RARE)
Cushing’s syndrome: (low/high) blood glucose, (low/high) BP.
High; high
Pt has thin extremities, central obesity, easy bruising, purple stretch marks, and hypertension. You also notice hyperpigmentation of creases. What’s at the top of your DDx?
Cushing’s syndrome (due to ACTH excess -
hyperpigmentation)
T/F: Cushing’s due to adrenal adenoma is usually accompanied by excess aldosterone and maybe excess androgens.
False - usually PURE cortisol excess
Pt with rapidly progressive muscle weakness, thin skin, hyperglycemia, and hypokalemia. Appears frail and reports recent weight loss. What are you worried about?
Adrenal carcinoma
Screening test for Cushing’s
24h urinary cortisol
24h urinary cortisol test: false neg for cushing’s may be due to..
Incomplete urine collection (be sure to measure Cr in sample to verify completeness)
You suspect Cushing’s in pt so you order 24h urine cortisol test. Levels come back high. What’s the next step?
Measure ACTH (in urine)
Cushing’s: both urine cortisol and ACTH are high. What’s the next step?
Measure inferior petrosal sinus ACTH levels before and after CRH injection; compare to antecubital ACTH
(is ACTH coming from pituitary or ectopic?)
If ACTH level in petrosal sinuses is (X)-fold greater than antecubital level, where is the tumor?
X = 3
Pituitary
Rx for Cushing’s syndrome from adrenal adenoma
Surg
Rx for Cushing’s disease
- Resect pit tumor (may recur)
- Irradiation
- Adrenalectomy, meds?