Salivary Hormone Testing

Clinical endocrinology laboratories routinely use immunoassays for the determination of hormones in serum (179,180,181). Since the 1980's this same technology has been developed and validated for use in salivary steroid hormone assays (182). Androbalance test kits employ the latest developments in this field, granting you access to cutting edge technology in salivary hormone analysis.

Steroids in the bloodstream are distributed between three compartments (182):

Tightly bound to specific plasma proteins such as sex hormone binding globulin (SHBG) and cortisol binding globulin (CBG)
Weakly and non specifically bound to albumin
Free/unbound

Distribution between the phases is steroid dependant (e.g. values for testosterone are approximately 44% bound to SHBG, 54% bound to albumin, and 2% free (183)). Irrespective of the steroid in question, typically only around 1-3% is unbound (25).

Only unbound free steroid is able to diffuse into cells, bind with intracellular receptors, and thereby exert a biological effect (182,184). This free, biologically active steroid fraction, is most readily determined by salivary analysis (25,182,184,185,186,187,188,191,192,195).

Mode of Entry of Steroids into Saliva:

Unconjugated steroids are relatively small, non-polar, lipophyllic molecules that readily diffuse through the phospolipid bilayer of the salivary duct's cell walls (185,186). Their salivary concentrations are independent of salivary flow rate (185,186) and demonstrate excellent correlations with the levels of free hormones in serum (184,185,186,187,188,189,190,191,194,195).

This diffusion of free steroid through the salivary ducts cell walls directly mimics the delivery of steroid molecules to target cells (25), accurately reflecting the true biological activity of these hormone (25,182,184).

Advantages of Salivary Assays:

They measure, directly and accurately, the biologically active steroid fraction entering cells (25,182,184,185,186,187,188,191,192,195).
They demonstrate excellent correlations with the levels of free hormones in serum (184,185,186,187,188,189,190,191,194,195).
Unlike total serum measurements they are not subject to errors arising from changes to binding protein concentrations (182,189,191,193,194).
Because they measure the biologically active hormone fraction, they are more sensitive at detecting certain conditions than traditional blood tests (192,193,195,196,197).
They are non-invasive and easily taken outside of the clinical setting (25,131,133,139,182,187,188,191,192,193), facilitating the study of hormonal circadian rhythms which may be important in some conditions (131,133,139,191,192,193).
Sampling is painless and stress free, thereby avoiding stress induced changes in the very hormones being measured, as can occur with blood sampling (131,133,191,193,198).
Hormones in saliva are stable for several weeks at room temperature and for several months when refrigerated or frozen, thereby facilitating multiple sampling events and easing sample submission (25,199,200,201,202).

Furthermore, salivary tests are accepted by some medical insurance plans (110) and are widely recognised as being accurate and reliable for clinical use (110,187,188,191,192,193,194,196,197,201), for psychological (203,204,205,206,207) and anthropological (208,209) research, and in sports science (207,210,211,212).