LABORATORY TESTS FOR ADRENAL FUNCTION
- · Tests of pituitary adrenal responsiveness.
- · Suppression tests -are measurement of target hormone response after suppression of its tropic hormone.
- · Stimulation tests
- · Plasma ‘Levels of ACTH and angiotensin II.
- · Measurement of urinary free cortisol
- · Measurement of urinary creatinine
- · Measurement of plasma and urinary level of steroids.
- · Measurement of peripheral plasma renin activity (PRA)
- · Measurement of DHEA (Dehydroepiandrosterone)
- · Measurement of cortisol and aldosterone.
- – Tests of pituitary adrenal suppressibility
- – Tests of mineralocorticoid suppressibility
- – Test of mineralocorticoid reserve
- – Test of glucocorticoid reserve- Rapid ACTH stimulation test
- Seeking a treatable cause of the primary disorder (eg, histoplasmosis involving the adrenal glands or a pituitary adenoma compromising normal pituitary function)
- evaluating mineralocorticoid secretion in patients without ACTH deficiency
- Determining whether the cortisol deficiency is dependent on or independent of ACTH deficiency
- Demonstrating inappropriately low cortisol secretion
HYPERFUNCTION OF ADRENAL CORTEX
- Excess of cortisol causes Cushing’s syndrome. Excess of aldosterone causes Aldosteronism.
- Excess of adrenal androgen causes Virilism (male features in females).
Diagnostic approach to suspected adrenal insufficiency