Tests

Question 1

what is the synacthen test used to detect?

Answer 1

Addison’s Disease

Question 2

which tests are used for Addison’s disease?

Answer 2

synacthen
insulin stress/ prolonged glucagon test
(both stimulation tests)

Question 2

what is the water deprivation tests used to detect?

Answer 2

Diabetes Insipidus (arginine vasopressin deficiency - AVPD)

Question 3

what is a positive result in water deprivation test?

Answer 3

it remains dilute
stays dilute after demopressin then it is a nephrogenic issue
if Ur/serum osmol ratio is low and improves after DDAVP then due to cranial DI

Question 4

what is the gold standard test for acromegaly?

Answer 4

GTT suppression test

(IGF1 tested - nearly always raised)

Question 4

what is GTT suppression test used for?

Answer 4

acromegaly
(gold standard)

Question 5

what are the tests used in Cushing’s ?

Answer 5

to establish cortisol excess:
Overnight 1mg dexamethasone suppression test (oral): first line
or 24hr urine free cortisol/ diurnal variation

to diagnose:
Low dose dexamethasone suppression test (Low Dose DST) (2 day 2mg/day)

Question 6

what is first line in establishing cortisol excess in Cushing’s ?

Answer 6

Overnight 1mg dexamethasone suppression test (oral)

Question 7

which test is diagnostic in Cushing’s?

Answer 7

Low dose dexamethasone suppression test (Low Dose DST) (2 day 2mg/day)

Question 8

what is Conn’s syndrome?

Answer 8

primary hyperaldosteronism
(independent of regulators - angiotensin II/ potassium)

Question 9

what is the process of testing in Conn’s syndrome?

Answer 9

1. measure aldosterone: renin ratio (ARR)
2. if raised -> saline suppression test
3. to confirm subtype - adrenal CT

Question 10

what is used to confirm aldosterone excess in Conn’s syndrome?

Answer 10

• Measure plasma aldosterone: renin ratio (ARR)
• If ratio raised investigate further with saline suppression test

Question 11

what is renin like with high aldosterone levels?

Answer 11

low

Question 12

what are investigations for secondary/ tertiary adrenal insufficiency? and result?

Answer 12

insulin tolerance test (insulin should cause ACTH increase usually - remains low in this case)
CRH stimulation test
MRI

Question 13

what is tested for in pregnancy tests?

Answer 13

hCG

Question 14

which hormones is the short synacthen test checking?

Answer 14

ACTH deficiency and adrenal cortical function

Question 15

what hormones is the insulin stress test checking?

Answer 15

measuring GH and ACTH reserves

Question 16

in insulin tolerance test what should rise in presence of hypoglycaemia induced by giving insulin?

Answer 16

GH
ACTH