Cortisol, Saliva
Use
This test is useful for screening for Cushing syndrome and diagnosing Cushing syndrome in patients presenting with symptoms or signs suggestive of the disease. Late‑night salivary cortisol measurement is an optimum test for diagnosis and elevated results should be confirmed with repeat salivary cortisol, midnight serum cortisol, 24‑hour urinary free cortisol collection, or overnight dexamethasone suppression testing. Referral to specialized centers or expert consultation is strongly recommended.
Special Instructions
Collection time is required. Patient should not brush teeth, eat, drink, or take any oral medication for at least 60 minutes before collection. Rinse mouth with water for 1–5 seconds, wait 10 minutes before collection. Use Sarstedt Salivette collection kit (T514) and collect between 11 p.m. and midnight, recording the exact time on the instruction sheet. If ordering on paper, include General Request (T239) or Renal Diagnostics Test Request (T830).
Limitations
Acute stress (including hospitalization and surgery), alcoholism, depression, and various drugs (eg, exogenous glucocorticoids, anticonvulsants) can obliterate normal diurnal variation. Cortisol levels may be increased in pregnancy and with exogenous estrogens. Midnight salivary cortisol assay cannot diagnose hypocortisolism or Addison disease due to limited assay sensitivity. Interpretation requires confirmation of elevated values.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 2142-8
- 2142-8
- 58674-3
- 58668-5
- 58642-0
Result Turnaround Time
3-6 days
Related Documents
For more information, please review the documents below
Specimen
Saliva
Volume
1.5 mL
Minimum Volume
0.6 mL
Container
Sarstedt Salivette
Collection Instructions
Patient should not brush teeth, eat, drink, or take oral medication for at least 60 minutes before collection; rinse mouth 1–5 seconds, wait 10 minutes; collect between 11 p.m. and midnight using Sarstedt Salivette, record collection time on instruction sheet.
Patient Preparation
Do not brush teeth, eat, drink, or take oral medication for at least 60 minutes; rinse mouth 1–5 seconds, wait 10 minutes before collection.
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 28 days |
| Frozen | 60 days |