Cushing's Info

Salivary Cortisol

The patient only has to chew a cotton tube for 2-3 minutes and place it in the plastic tube. Late-evening salivary cortisol is not intended to replace the current standard screening test - measurement of a 24 hr urine free cortisol. However, the salivary cortisol test can be extremely useful for patients suspected of having intermittent Cushing's syndrome.

Cushing's syndrome - endogenous hypercortisolism - is characterized by a loss of circadian rhythmicity. 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 cortisol, 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 can make the diagnosis of endogenous hypercortisolism.

A simple way to sample saliva is by using a Salivette. This device consists of a cotton tube and plastic tubes. The patient only has to chew the cotton tube for 2-3 minutes and place it in the plastic tube. The tube is then transported to our lab for analysis.

Late-evening salivary cortisol is not intended to replace the current standard screening test - measurement of a 24 hr urine free cortisol. However, the salivary cortisol test can be extremely useful for patients suspected of having intermittent Cushing's syndrome. Due to the convenience of sample collection, the patient can sample saliva several evenings in a row. In fact, our clinical endocrinologists routinely order 2-3 consecutive late-evening salivary cortisol samples.

• More on Salivary Cortisol from NIH
• On the Message Boards - Salivary Testing
• Patient Question: Does anyone know how to use this test? I have the saliva kit!!! four tubes... lab said there was instructions inside. yes! there is but, no time to do it. Is it a four day or three a day? Geesh! Does it have to be taken to the lab one day at a time so It is handled properly? Anyone? Thanks, Cherlyn
  • Patient Answers
    • do salivaries at 11 pm. Putting the cotton in your mouth and chewing it until it is saturated. put back in tube and put in freezer. Make sure to mark date on tubes. Turn them in all at the same time.
    • Agree with the above. The only difference is I was told to collect mine at midnight, but I would guess this would depend on the endocrinologist and what they wanted. I wasn't given any cotton to chew on though, just had to collect salivary specimen in sterile container and freeze. So I guess it depends on what kit you are given as well. Good luck.
    • We were told to only chew for one minute.
    • I did mine at 11pm, chewed nasty cotton until it was soaked through which took about a minute, dropped it into the tube, but was never told to freeze it, I just turned it in as is.
    • Mine are at 11 pm as well. Told to refrigerate but I believe that is just so it's not smelly. I don't think anything happens if it weren't to be kept cold. It doesn't "break down".