Saliva Testing for Hormones
Hormones play a critical
role in maintenance of health and our sense of well being, as well as
in certain disease processes. Therefore it may be important to know if
there are any hormonal imbalances that may be affecting your health.
Also, testing is important to monitor the treatment prescribed by your
doctor, to make sure the treatment is having the desired effect, and to
prevent abnormal hormone levels.
After hormones are made in
the various glands, they are secreted into the blood stream where they
bind to certain protein “carriers.” Only a small fraction (1-5%) of a
given amount of steroid hormone breaks loose from the carrier protein
in the bloodstream and is free to enter target tissues to exert its
effect. This free or unbound hormone is what we want to measure, since
it is active or bioavailable to the target tissue. Some hormones, such
as thyroid, are very tightly bound to the carrier protein, while other
hormones are less strongly bound.
Many studies have shown
that there is a strong correlation between the levels of steroid
hormones in saliva and the bioavailable (free) levels of steroids in
the bloodstream. The amount of steroid hormone that enters the salivary
ducts and then the saliva is representative of the fraction of steroids
in the bloodstream that is bioavailable. In fact, one study showed
that, after administration of progesterone and estrogen cream, breast
tissue (target tissue) levels of the hormones increased significantly,
saliva levels increased, but the was no change in the blood levels!
Compared
to blood testing, saliva testing is painless, convenient, and easy. In
addition, saliva testing can be more easily timed to obtain samples at
critical times of the day to get more accurate results than with blood
testing. Also saliva testing much more easily allows multiple samples
to be taken either during the day or over the course of a month.
Hormones
in saliva are exceptionally stable, allowing wide latitude in
collection and shipment. Samples can be stored at room temperature for
at least a week without loss of activity, so samples can be shipped to
the testing facility by regular mail. Blood, on the other hand, must be
kept cool on ice packs, increasing costs for shipping as well as the
likelihood of error due to improper handling.
Most insurance
plans do not pay for the cost of saliva testing. But the cost generally
is reasonable, especially considering the potentially positive benefits
for your health. Some labs that do saliva testing may submit the bill
to your insurance company or give you a form that you may submit
yourself.
For more information on saliva testing, check the following resources:
http://www.salivatest.com/store/testing.html
http://www.diagnostechs.com/main.htm