Introduction
Doctors will regularly order blood tests to assess your health. This has been the traditional mainstay of keeping an eye on things.
Over the last few years, saliva based hormone testing has gained in popularity. It has the benefit of being less painful than a blood test and more convenient. This is especially useful when multiple samples have to be taken throughout the same day. In some cases, for example complex menstrual disorders, samples need to be taken multiple times throughout the cycle in which case saliva testing has a clear advantage for the patient subject to this.
At this stage, saliva testing is mostly used to check adrenal and sex hormones and doctors rely on blood tests for other hormones. These tests are non invasive, easy to obtain multiple times and may be more sensitive or accurate than blood tests for some hormones. They are being used more and more.
These tests are generally regarded as being quite accurate; they also measure the amount of hormone ‘available’ for cells rather than just bound to proteins in the blood.
What is saliva?
A small percentage of saliva comes from components of blood leaking through the blood vessel into the space between the teeth and gums. This is called crevicular fluid and is what is measured in the salivary hormone tests.
Hormones mostly end up in the saliva by filtration or diffusion out of blood, however some are actually synthesised, stored and released by cells in that area.
The rate at which hormones move into the saliva varies; the rate of saliva production itself can also affect the results of salivary hormone tests. For analytes influenced by flow rate, the unit is given as a flow rate product. Flow must be controlled for or factored into the interpretation of the results.
There are various techniques of saliva storage to circumvent these problems and the manufacturer of the test will hold knowledge on this matter. Interfering matter includes blood and food and so you may be asked to take the test prior to eating.
What can be tested for in saliva?
There are multiple hormones which can be tested for in saliva based on the commercial kit available.
Hormones
- Aldosterone (a kidney hormone)
- Androstenedione (androgen; a male type hormone)
- Testosterone
- Cortisol (stress hormone from adrenal gland)
- DHEAS (adrenal gland hormone)
- Estradiol, estriol, esterone (estrogen)
- Progesterone
- Adiponectin, leptin, ghrelin (hunger hormones)
- Oxytocin (love hormone)
Immune
- Secretory Immunoglobulin A
- Beta 2 microglobulin (bone cancer marker)
- Cytokines (inflammatory chemicals)
- C reactive protein (inflammatory chemical)
Nervous system
- Alpha Amylase (sAA test looks at the nervous function of the gut)
- Vasoactive intestitinal peptide (VIP) tests for a rare tumour in the gut
- Chromagranin A
- Neuropeptide Y
Antibodies and infections
- Measles
- Mumps
- Rubella
- Hep A, B, C
- HIV
- Herpes
References
Granger and Johnson, ‘Salivary Biomarkers’ 2013
In: M.D. Gellman & J.R. Turner (eds.), Encyclopedia of Behavioral Medicine,
DOI 10.1007/978-1-4419-1005-9, # Springer Science+Business Media New York 2013
