Cortisol, LC/MS, Saliva, 4 Samples

Quest Diagnostics

Sample type: Saliva

Requires fasting: No

Sample collection required at Quest Diagnostics location

Details

Cortisol, LC/MS, Saliva, 4 Samples - Salivary cortisol level, particularly late-night salivary cortisol (LNSC) level, is useful in screening for endogenous Cushing syndrome. Two or more positive results of LNSC tests may be used to confirm Cushing syndrome. LNSC measurement may also be used to monitor for recurrence of Cushing disease.

Biomarker summary

Cortisol, 1st specimen, Saliva
Cortisol, 2nd specimen, Saliva
Cortisol, 3rd specimen, Saliva
Cortisol, 4th specimen, Saliva

Additional details

Estimated days for results: Results should be available in 2 - 5 business days after the sample is collected

Details

Normally, the secretion of cortisol has a circadian rhythm. Patients with Cushing syndrome often lose the late-night circadian nadir. Therefore, an elevated LNSC level may provide initial evidence for Cushing syndrome. Two or more positive results of LNSC tests may establish the diagnosis of Cushing syndrome if non-neoplastic hypercortisolism (pseudo-Cushing syndrome) is excluded. Because saliva is convenient to collect, LNSC testing is especially useful for individuals who need to provide multiple specimens over time for the evaluation of cyclic Cushing syndrome [1].

Annual LNSC testing is recommended to monitor for the recurrence of Cushing disease after pituitary surgery. LNSC testing may also be used in assessing treatment outcomes in patients receiving medical therapy for Cushing disease [1].

Non-neoplastic hypercortisolism caused by obesity, psychiatric disorders, alcohol use disorder, and polycystic ovary syndrome may increase LNSC levels. LNSC testing should not be used to screen for Cushing syndrome in individuals without normal day and night cycles. LNSC testing has low sensitivity in patients with adrenal tumors [1].

Other tests, such as urinary free cortisol (test code 14534) and dexamethasone suppression test (test code 6921), may also be used to screen for Cushing syndrome. Choice of tests should be individualized based upon clinical scenarios [1].

The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.

Reference
1. Fleseriu M, et al. Lancet Diabetes Endocrinol. 2021;9(12):847-875.

What type of sample is required for this test?

0.5 mL saliva collected in each of four separate Salivette® Cortisol with blue screw-cap

Test Resources

For more information, please consult your healthcare provider.

Average sample processing time

2–5 business days

Health categories

Adrenals and stress

Patient instructions

Collect your saliva sample at least 60 minutes after brushing teeth, eating a meal (liquid/solid food intake), or oral intake of medication.

Collect your saliva sample 10 minutes after rinsing your mouth with water in order to avoid contamination of the saliva by interfering substances.

Collection Options with Fullscript
Sample collection requires a test kit that can be picked up at a nearby Quest Diagnostics Patient Service Center.

Quest Diagnostics Patient Service Centers (PSC)

Location: Visit a nearby Quest Diagnostics Patient Service Center.
Cost: $10 sample collection fee (paid during lab order checkout).
Scheduling: Schedule your appointment here. Appointments are recommended to reduce wait times. Walk-ins are accepted, but may experience delays. Aim to arrive 10 minutes before your appointment.
Collection Instructions:

Bring a valid ID.
Bring your digital or printed requisition form, available in the Labs tab of your Fullscript account.

Check-in: Scan the QR code from your confirmation email or follow kiosk instructions.
More Info: Quest Diagnostics collection guide

In-office phlebotomy instructions

Specimen

Preferred Specimen(s): 0.5 mL saliva collected in each of four separate Salivette® Cortisol with blue screw-cap
Alternative: NA
Minimum Volume: 0.2 mL
Collection Instructions: NA

Storage and shipping instructions