Laboratory Medicine Program

Cortisol, urinary free

Clinical Decription:
Cortisol is the primary glucocorticoid hormone synthesized and secreted by the adrenal cortex. Cortisol is essential for life, regulating carbohydrate, protein and lipid metabolism, maintaining normal blood pressure, and inhibiting allergic and inflammatory reactions. Cortisol is synthesized and secreted by the cortex of the adrenal gland under the direction of adrenocorticotropic hormone (ACTH). ACTH is secreted in a circadian pattern by the anterior lobe of the pituitary gland in response to corticotropin releasing hormone (CRH) secretion by hypothalamus. Increased ACTH levels stimulate cortisol secretion. The increased cortisol levels inhibit CRH secretion, which subsequently inhibits ACTH secretion. This negative feedback mechanism results in decreased cortisol levels. Addison?s disease is caused by primary adrenal insufficiency due to the metabolic errors or destruction of the adrenal cortex. Cushing?s syndrome is caused by increased levels of cortisol due to either primary or secondary adrenal hyperfunction. Causes of primary adrenal hyperfunction are adrenal tumours and modular adrenal hyperplasia. Increased cortisol levels are induced by pregnancy and by stress due to depression, trauma, surgery, hypoglycemia, alcoholism, uncontrolled diabetes, and starvation.

Method: Chemiluminometric technology; Architect i2000

Component Tests Used: n/a

Reference Ranges Used:
12-486 nmol/24h

Specimen Type: Urine 24 hour
Volume: 20 mL mL (minimum: 10 mL mL)

Shipping: 4C

Special Instructions: Discard first morning sample, collect all other urine for a 24 hour period, to include second morning sample. Record volume and aliquot.

Testing Schedule(s): Daily.

Turnaround Time: 2 days

For more information, call 416.340.5227 or 1.866.865.5227