7: Adrenal gland disorders

Question 0

Cortisol- action

Answer 0

• required for the actions of catecholamine (so indirectly it helps with stress)
• Protein: breaks down-> mobilize it to liver for gluconeogenesis
• Fat: lipolysis-> gluconeogenesis
• Carbs: increase blood glucose level (anti-insulin; can cause DM)
• Anti-inflammatory
• Immunosuppressive
• Inhibit fibroblasts
• also causes HTN

Question 1

Adrenal- info

Answer 1

Medulla: secrete Catecholamine (helps deal with stress, sympathetic)
Cortex:
-Aldosterone (G) (affectss distal tubule of the kidney)
-Glucocorticoids (it comes out of both F & R)**
-DHEA (R)

Question 2

Cushing’s syndrome

Answer 2

Exogenous- Steroid intake (look for “no medical hx” to rule out) (MCC)
Endogenous-
-Pituitary adenoma (Cushing’s disease)
-Adrenal adenoma
-Ectopic ACTH secreting tumor (small cell carcinoma of lung, carcinoid tumor of thymus, pancreatic cancer)

Question 3

Truncal obesity- cc

Answer 3

Cortisol receptors are mainly in periphery

Insulin receptors are mainly in central part of body

Question 4

Purple striation

Answer 4

Striation has pit due to loss of protein-> subcutaneous tissue (you dont see pitting of striation in pregnancy**)
Purple: blood vessels are fragile so see internal bleeding

Question 5

Hirstism and Male pattern balding on Cushings

Answer 5

Slight increase in adrogen due to cortisol is produced in Reticularis also.
Dont affect males enough but females get that kind of sx

Question 6

Fragile bones in Cushing

Answer 6

Decreased absorption of Ca++ by GI

Question 7

Cushing’s syndrome- additional sx

Answer 7

Prolonged period of increased Cortisol (4-6 weeks effect starts, takes 1yr for the effect to go away)***
- Decreased: GnRH, CRH, Dopamine, TRF, GHRH
Amenorrhea, abortion, galactorrhea
Loss of pubic hair, growth retardation in child, hypothyroidism

Question 8

Cushing- investigation

Answer 8

Urinary free cortisol test (False positive: stress, alcohol, obesity, CRF, anorexia, exercise, illness)
Dexomethasone suppression test
CRH stimulation (positive: PA)
Inferior petrosal sinus sample

Question 9

Dexomethasone suppression test (4 different kinds)

Answer 9

Over night (11pm-> 8am: since a surge comes in the morning)
-Low dose (1mg): >10ug/dL: Cushing’s syndrome
-High dose (8mg): suppression means Pituitary adenoma
48hrs
-Low dose: in case dont wanna give high dose to start with. could suppress and means PA or not and try high dose
-High dose: suppression means Pituitary adenoma
Now look at ACTH in case of no suppression
-High: ectopic
-Low: adrenal adenoma (due to negative feedback)

Question 10

Inferior sinus sampling

Answer 10

Take sample from inferior petrosal sinus-> if ACTH is 3 times high than periphery, it is pituitary adenoma
-since pituitary drain to the IP sinus

Question 11

Confirmatory test for Cushings

Answer 11

MRI**

CT

Question 12

Cushing- rx

Answer 12

Removal of tumor: adenoma
Treat accordingly: carcinoma
Radiotherapy preferred:
-Child
-Post-op tumor recurrence
Suppress adrenal glands: drugs (ketoconazole**)

Question 13

Aldosteronism- cc

Answer 13

Retain sodium and water (HTN-> LV hypertrophy), Lose K+ and H+ (Arrhythmia, Metabolic alkalosis) (low K cause prominent U waves)
Primary (Con syndrome): adrenal adenoma, Bilateral nudular hyperplasia, adenocarcinoma (Ddx by bx and see if its bilaterally increased or unilaterally)
-high aldosterone-> low renin* (ratio higher than 25)
Secondary (Barter’s syndrome): hypovolumia, renal artery stenosis
-high renin*-> increased aldosterone

Question 14

Saline stimulation test

Answer 14

Correct the hypovolumia-> Secondary aldosteronism gets better

Question 15

Adrenal insufficiency

Answer 15

Primary (addison’s disease)
-Immune (MC)*
-Infection (TB, viral, fungal)
-Hemorrhage; Waterhouse-Friedrichsen syndrome (meningococcimia)
-Radiation
Secondary: diseases of pituitary gland (Low ACTH)

Question 16

Addisons- sx

Answer 16

Hyperpigmentation (high ACTH/ MSH)
Anorexia
Nausea
Loss of appetite
Weakness
K+ high, Na+ low (metabolic acidosis)

Question 17

Addison- rx

Answer 17

Hormonal replacement therapy

Question 18

2ndary adrenal insufficiency

Answer 18

No pigmentation (low ACTH)
No low Na+: there is low production of aldosterone
Low pituitary hormones (LH, FSH)
-amenorrhea, abortion, etc

Question 19

ACTH stimulation test

Answer 19

Ddx of primary/ secondary adrenal insufficiency
Increase in cortisol: secondary
No increase: primary

Question 20

Congenital adrenal hyperplasia (CAH)- info

Answer 20

due to low Cortisol-> high ACTH-> excess of Aldosterone or sex hormone

21: only androgen secretion (F: pseudohermaphroditism in new born or virilization. M: big genitalia, short statue, precocious puberty), salt wasting
11: high androgen. weak aldosterone (all the 21 sx with HTN)
17: low androgen, high aldosterone HTN with (M: male pseudohermaphroditism. F: pretty normal)