Dynamic Tests in Endocrinology

Dynamic tests in endocrinology are based on an understanding of key regulators of hormonal secretion. A simple rule of thumb is to suppress a hormone if you suspect it is being over-secreted. Conversely, stimulate a hormone if you suspect it is being under secreted or absent.

Sample infographic of a dynamic test

This is a sample visual infographic

A Collection of Dynamic Tests

Cosyntropin (cortrosyn) stimulation test : A dynamic test for the evaluation of suspected adrenal insufficiency. The test cannot distinguish between primary and secondary AI Limitations of this testEstrogen in OCPs may increase corticosteroid-binding globulin and thus increase total serum cortisol.Low albumin can lead to a spuriously low serum cortisolIt does not distinguish between primary and secondary AI (normal stimulation test if adrenocortical atrophy has not set in yet)	Print version
Growth hormone suppression test : This dynamic test is used for the evaluation of suspected acromegaly. Limitations of this testGH levels may not be suppressed in patients liver disease, renal insufficiency, uncontrolled DM, pregnancy, estrogen therapy or anorexia.Possibility of a paradoxical increase in GH during an oral glucose tolerance test.	Print version
GHRH-Arginine Growth hormone stimulation test : This dynamic test is used for the evaluation of suspected growth hormone deficiency. Alternatives include the ITT and Glucagon stimulation tests	Print version
Glucagon Stimulation Test: This dynamic test is used for the evaluation of suspected growth hormone deficiency. Alternatives include the ITT and GHRH-arginine. Limitations of this testAssociated with significant nausea and vomiting. As a precaution, patients should therefore be nil per os, except for water, after midnight and during the test. Prophylactic anti-emetics are advised.Risk of hypoglycemia after the test (consuming small meals is reasonable)	Print version
Insulin Tolerance Test : This dynamic test is used for the evaluation of suspected growth hormone deficiency. It is a gold standard test for evaluating suspected secondary adrenal insufficiency.	Print version