Cortisol, PM, Serum

Cortisol PM - NCMC

In-Patient: 1.0 mL plasma from Lithium Heparin
Out-Patient: 1.0 mL serum from Serum SST or Red Top

0.5 mL

To test for adrenal cortical hyperfunction (Cushing’s syndrome)

• Inpatients: Obtain a cortisol a.m. at 8 a.m. on day 1 (Cortisol AM), and a cortisol p.m. at 8 p.m. on day 1(Cortisol PM). At 11 p.m. on day 1, give patient a 1 mg tablet of dexamethasone (Decadron®). Obtain cortisol a.m. at 8 a.m. on day 2 (Cortisol AM)
• Outpatients: Contact Outpatient Oncology at 970-378-3807 to schedule test.

Note:  For adrenal function studies, see CORTBASE, CORT30, CORT60, CORT90, Cortisol Random-.

Temperature Stability
20-25 °C 24 hours
2-8 °C 4 days
-20 °C 12 months
Storage Temperature: Store at 2-8 °C.
 

Gross hemolysis, plasma

Monday through Sunday; Continuously

Same day

Refer to the Chemistry Reference Range document in the Resources on the test list home page. 

Cortisol (hydrocortisone) is quantitatively the major glucocorticoid product of the adrenal cortex. The main reason to measure cortisol is to diagnose human diseases which are caused by the overproduction of cortisol in Cushing’s syndrome (CS), deficiency of adrenal steroid excretion in Addison’s disease, and for therapy monitoring (e.g. therapies designed to reduce the excessive production of cortisol in Cushing's syndrome and hormone replacement therapy in Addison's disease). Cortisol plays an important role in the regulation of many essential physiological processes, including energy metabolism, maintenance of electrolyte balance and blood pressure, immunomodulation and stress responses, cell proliferation as well as cognitive functions. The major fraction of cortisol circulates bound to plasma proteins as corticosteroid binding globulin and albumin. The biologically active free fraction comprises only 2-5 % of the total hormone concentration. Elevated serum levels can be found in stress responses, psychiatric diseases, obesity, diabetes, alcoholism and pregnancy, which may cause diagnostic problems in patients with Cushing's syndrome. Low levels of cortisol are seen in patients with rare adrenal enzyme defects and after long-lasting stress. For diagnostic purposes the following analyses are used: Total and free cortisol in serum.