Cushings Week 6

Question 1

Describe normal function of cortisol.

Answer 1

B- maintains BP
B- bone formation inhibition
I- anti- Inflammatory (important- body’s response to stress)
I- decreases Immune function
G- increases glucose production, lipolysis (breakdown of fats/lips), proteolysis (protein breakdown)
Remember BBIIG

Question 2

how are cortisol levels regulated normally?

Answer 2

hypothalamus releases corticotropin releasing hormone (CRH) and vasopressin/ antidiuretic hormone (ADH) —>which stimulate the anterior pituitary to make adrenocorticotropic hormone (ATCH)—> which stimulates the adrenal cortex to produce cortisol. The cortisol then feeds back to the hypothalmus to suppress levels of ACTH and CRH depending on the needs of the pt. Under non- stress conditions, cortisol is secreted in a pronounced circadian rhythm, with higher levels early in the morning and lower levels late in the evening.

Question 3

under stressful situations, what happens to the levels/ secretion of everything?

Answer 3

the secretion of CRH, ACTH, and cortisol increases, and the circadian variation is blunted

Question 4

why is it hard to evaluate a pt for suspected Cushings?

Answer 4

Because of the wide variation in cortisol levels over 24 hours and appropriate elevations during stressful conditions, it may be difficult to distinguish normal secretion from abnormal secretion.

Question 5

Cushings is ?

Answer 5

nonspecific name for any source of excessive glucocorticoids (basically too much cortisol in the body)

Question 6

What are the clinical symptoms of excessive levels of cortisol? B

Answer 6

(think of all the the things cortisol does)

controls BP so –> Hypertension, atherosclerosis, congestive heart failure, and edema

Question 7

What are the clinical symptoms of excessive levels of cortisol? B

Answer 7

inhibits bone formation so –> Osteoporosis and fractures

Question 8

What are the clinical symptoms of excessive levels of cortisol? I

Answer 8

decreases immune function so –> Increased rate of infections and poor wound healing

Question 9

What are the clinical symptoms of excessive levels of cortisol? G

Answer 9

increases glucose so –> Obesity, especially central (truncal) obesity, with wasting of the extremities, moon facies, supraclavicular fat pads, and buffalo hump

Question 10

What are the clinical symptoms of excessive levels of cortisol?

Answer 10

proteolysis (increased protein breakdown) so –> Muscular weakness, especially proximal muscle weakness, and atrophy

Question 11

What are the clinical symptoms of excessive levels of cortisol?

Answer 11

increases lipolysis (breakdown of fat) so–> Thinning of the skin, with facial plethora, easy bruising, and purple abdominal striae ( d/t impaired collagen synthesis)

Question 12

What are the clinical symptoms of excessive levels of cortisol?

Answer 12

other:

• Gonadal dysfunction and menstrual irregularities (from excess production of adrenal androgens under ACTH stimulation)
• Psychologic disturbances (e.g., depression, emotional lability, irritability, sleep disturbances)

Question 13

What is the cause of death in patients with Cushing syndrome?

Answer 13

Patients with inadequately treated Cushing syndrome have a markedly increased mortality rate (four-to fivefold above the normal rate), usually from cardiovascular disease or infections.

Question 14

4 main causes of Cushings?

Answer 14

1 cause-Exogenous glucocorticoids (ACTH-independent)

Adrenal tumors (ACTH-independent)
Pituitary Cushing syndrome (ACTH-dependent)
Ectopic ACTH production (ACTH-dependent)

Question 15

Do age and gender matter in the differential diagnosis of Cushing syndrome?

Answer 15

Of patients with Cushing’s disease (pituitary tumors), 80% are women and age range is 20- 40 yrs
-but ectopic ACTH syndrome is more common in men aka men more at risk for extrapituitary tumors (i.e. lung). age range for this is 40- 60

Question 16

how to diagnose cushings?

Answer 16

1st do overnight low-dose dexamethasone suppression test. Give 1mg dexamethasone at 11p and then check serum cortisol at 8am the next day

• Normal = suppression of CRH, ACTH, and cortisol aka cortisol will be low
• endogenous Cushing syndrome = should not suppress cortisol so it will be high still (remains > 1.8 μg/dL)

Question 17

My patient underwent a low-dose dexamethasone suppression test. The morning cortisol level is 7 μg/dL. Does she have Cushing syndrome?

Answer 17

Probably not. Acute or chronic illnesses, depression, and alcohol abuse activate the hypothalamic-pituitary-adrenal axis because of stress and make the patient resistant to dexamethasone suppression. In fact, because Cushing syndrome is so rare, a nonsuppressed cortisol level after dexamethasone is more likely to be a false-positive result, rather than truly indicating the presence of Cushing syndrome.

Question 18

Further biochemical testing confirms that the patient has Cushing syndrome. What should I do next?

Answer 18

After you have made the biochemical diagnosis of Cushing syndrome, the next step is to determine whether she has ACTH-dependent or ACTH-independent disease. This distinction is made by measuring plasma levels of ACTH. Measurements should be repeated a number of times because secretion of ACTH is variable.

Question 19

The patient’s ACTH level is “normal.” Was the original suspicion of Cushing syndrome incorrect?

Answer 19

No. A normal or slightly elevated ACTH value is the usual finding in ACTH-secreting pituitary adenomas.

Question 20

Suppressed ACTH levels

Answer 20

suggest an adrenal tumor

Question 21

More marked elevations of ACTH suggest

Answer 21

ectopic secretion of ACTH, although small carcinoid tumors also have normal or mildly elevated ACTH values.

Question 22

After the diagnosis of ACTH-dependent Cushing syndrome, what is the next step?

Answer 22

MRI- but may or may not see a tumor could be very small- basically refer

Question 23

treatment for cushings

Answer 23

usually surgery.

also 1 med- metyrapone- blocks corticosteroid