Lab Test

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Cortisol, Saliva

Test Codes

EPIC: LAB3438, Beaker: XCORS, Mayo: SALCT

Department

Send Outs

Instructions

  • A special collection kit must be obtained from Send Outs Laboratory, 248-551-9045, or Outreach Client Services, 248-551-1155.
  • It is recommended that the specimen be collected between 11:00 pm – midnight.
  • Do not collect sample within 15 minutes after eating a meal or within 12 hours after consuming alcohol, immediately after brushing teeth, or after any activity that may cause gums to bleed.

Specimen Collection Criteria

Collect: Saliva on the provided swab.

  • Remove top cap of the tube to expose the swab.
  • Place swab directly into the mouth by tipping the tube so the swab falls into the mouth. Do not let fingers touch the swab.
  • Keep the swab in the mouth for approximately 2 minutes. Roll the swab in the mouth. Do not chew the swab.
  • Spit the swab back into the tube. Do not let fingers touch the swab.
  • Replace the cap. Make sure cap is pushed on tightly.
  • Record the exact collection date and time on barcode label.
  • Return the tube (with swab) within 24 to 48 hours.

Physician Office/Draw Specimen Preparation

Maintain specimen refrigerated (2-8°C or 36-46°F) prior to transport.

Preparation for Courier Transport

Transport: Provided swab, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

Transport: Provided swab, refrigerated (2-8°C or 36-46°F).

Laboratory

Sent to Mayo Clinic Laboratories in Rochester, MN.

Performed

Monday, Wednesday, Friday.
Results available in 2-5 days.

Reference Range

By report.

Test Methodology

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

Clinical Utility

Salivary cortisol levels can be used in place of free plasma cortisol levels in patients. Nighttime salivary cortisol measurements are a simple noninvasive screening test for Cushing's syndrome.

In normal patients, cortisol levels peak in the early morning hours and decrease to substantially lower levels at night. Rather than the normal decrease in late evening, patients with Cushing's syndrome of any cause fail to decrease cortisol secretion in the late evening. Therefore, the measurement of elevated late evening cortisol is helpful in the diagnosis of Cushing's syndrome. Obtaining a late night, unstressed plasma cortisol is virtually impossible in most clinical practices. Salivary cortisol is in equilibrium with the free, biologically active portion of cortisol in the plasma. Therefore, if one obtains a saliva sample in patients at bedtime in their homes under unstressed conditions, one more readily can make the diagnosis of endogenous hypercortisolism.

CPT Codes

82533
LOINC:  2398-6

Contacts

Last Updated

7/21/2024

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