Endocrine - Diagnostic Tests

Question 1

Diagnosis of GH Deficiency

Answer 1

Insulin tolerance test
GHRH test
Arginine-L dopa test
Glucoagon-stimulation test
Serum-IGF

Question 2

Diagnosis of acromegaly

Answer 2

Elevated IGF-1 (screen)

75mg oral glucose challenge: GH SHOULD suppress to 1-2 hours post intake
(** 20% get a paradoxical rise **)

Prolactin is elevated in 25%

Question 3

Diagnosis of hyperprolactinaemia

Answer 3

Basal fasting prolactin level
Measure TFTs
MRI

Question 4

Diagnosis for Cushings

Answer 4

SCREENING:
1)24 hour urine free cortisol

2) Late night cortisol
- late evening 11pm serum cortisol
- late night/midnight salivary cortisol

3) Overnight 1mg dexamethasone suppression test

DIAGNOSIS:
Test ACTH
if <10ng/mL --> ACTH independent
if 10-20ng/mL --> need CRH testing
if >20ng/mL --> ACTH depdendent