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Flashcards in Eval Of Hormones Deck (28)
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0
Q

Recommended tests for Cushing’s syndrome

A

UFC (urinary free cortisol)
Low dose or overnight dexamethasone test
Night-time salivary cortisol

1
Q

Lab findings for Cushing’s syndrome

A

CBC- leukocytosis, lymphocytopenia, and decreased eosinophils

CMP- hyperglycemia, hypokalemia, and hypernatremia

Thyroid function- slightly low T3 & TSH

2
Q

What problem may occur with the 24-hr urinary free cortisol (UFC) that may camouflage a patient with Cushing’s?

A

Values may appear normal if subjects cortisol is high at night and low during the day
Loose diurnal component while might have avg amount

3
Q

What test would accurately reflect the diurnal pattern of cortisol?

A

Normal individuals and patients with pseudo-Cushing states have a pronounced diurnal rhythm with the highest values in the morning and the lowest at night
Patients with Cushing’s syndrome lack their diurnal variation of cortisol

THE DIURNAL PLASMA CORTISOL TEST - great because it reflects this variation

4
Q

Test that is easier for pt to carry out and still reflects diurnal pattern

A

Diurnal salivary cortisol test

5
Q

What does the Overnight dexamethasone test show?

A

Dexamethasone is a synthetic steroid that will suppress ACTH secretion in normal ppl
This negative feedback system does not work properly in patients with Cushing’s syndrome (cortisol production not suppressed)

6
Q

Addison’s disease- primary adrenal insufficiency

Lab findings

A

CMP- hyponatremia, hyperkalemia, hyperglycemia
CBC- normocytic normochromic anemia
Thyroid function- increased thyroid stimulating hormone (TSH)

7
Q

What does Rapid ACTH stimulation test show?

A

Pre- blood draw
Administration of synthetic ACTH
30-60 min after, 2 blood samples drawn, one for cortisol and one for aldosterone
For DX of Addison’s both cortisol and aldosterone show minimal or no change in response toACTH

8
Q

Synacthen test- what does it measure?

A

Uses synthetic ACTH analogue to trigger adrenal glands to produce cortisol. If this doesn’t happen, know there’s dysfunction in adrenals

9
Q

Cushing’s syndrome- adrenal function testing

A

Cortisol- high
ACTH- low

Adrenals themselves overproducing cortisol, pituitary just fine, so down-regulate ACTH

11
Q

Cushing’s disease- adrenal function testing

A

Cortisol- high
ACTH- high

Problem is in pituitary - overproducing ACTH with is overstimulating the adrenal glands

12
Q

Addison’s disease

A

Cortisol- low

ACTH level- high

13
Q

Hypopituitarism

A

Cortisol- low

ACTH level- low

14
Q

Salivary Adrenal Function Test:

A

The Preferred Test for Adrenal Fatigue
Use 1 day collection (4 vials) as baseline.
Have patient record S&S, date and time of sample on separate sheet.
If possible, take blood sugar at same time as cortisol level

15
Q

Growth hormone

A
Hypothalamus releases GHRH
Anterior Pituitary releases GH
GH induces release of Insulin-like Growth Factor
Triggers = Tissue growth/ repair
Increase protein synthesis, growth, etc.
Increase GH and release of somatostatin 
shuts off GHRH and GH release
16
Q

Quantitative GH

A

fasting level

isn’t a good test

17
Q

Provocative test for susptected deficiency

A

Hypoglycemia causes GH levels to rise

18
Q

Suppression test

A

Hyperglycemia suppresses GH (should see suppression in GH to correct for this)

19
Q

Testing Insulin-like Growth Factor
 (IGF)

A

IGF-1 levels reflect average daily levels of GH- easier to test
Low values imply deficiency
High values are seen in acromegaly and gigantism
IGF-1 levels do not fluctuate throughout the day

20
Q

Regulation of PTH

A

the dominant regulator of PTH is plasm Ca2+

PTH secretion responds to small alterations in plasma Ca2+ immediately (within seconds)

21
Q

Function of PTH

A

PTH acts directly on the bones to stimulate Ca resorption and kidney to stimulate Ca reabsorption
PTH also acts indirectly on intestine by stimulating Vit D synthesis

22
Q

Hypercalcemia results from

A

Combined effects of PTH-induced bone resorption, intestinal calcium absorption and renal tubular reabsorption

23
Q

Hypocalcemia occurs when

A

there is inadequate response of the Vitamin D-PTH axis to hypocalcemic stimuli

24
Q

Pseudohypoparathyroidism

A

Due to defect in PTH receptor-adenylate cyclase complex

- present as hypothyroid patient because parathyroid receptors aren’t working properly

25
Q

Parathyroid hormone testing

A

diurnal variation - highest at 2am

levels vary with diet so need fasting specimen

26
Q

Primary hyperparathyroidism test

A

high PTH and high calcium levels (due to parathyroid neoplasm)

27
Q

Secondary hyperparathyroidism test

A

high PTH and normal/slightly low calcium levels (early chronic renal failure)

28
Q

Tertiary hyperparathyroidism test

A

high PTH and high calcium levels (late stage chronic renal failure)