Salivary testosterone in hirsutism: correlations with serum testosterone and the degree of hair growth.

Testosterone (T) concentrations in saliva and serum were measured in 53 women with various degrees of hirsutism and hyperandrogenism. The bioavailability of T was judged by comparing the correlations among the grade of hirsutism, salivary testosterone (SaT), and serum total and free T (fT) and sex hormone-binding globulin (SHBG) levels. The effect of body mass index on the correlations was also studied. The high SaT concentrations [mean, 237.6 +/- 66.7 (+/- SD) pmol/L] compared to the serum fT concentrations (mean, 29.1 +/- 11.8 pmol/L) in hirsute women may reflect the bioavailability of albumin-bound T or an ability of the salivary glands to metabolize steroids. SaT was more closely related to the T/SHBG ratio (mean, 82.5 X 10(-3) +/- 54.8), reflecting the non-SHBG-bound fraction of T, than to serum fT, which might support the former theory. SaT correlated better to the degree of hirsutism (rho = 0.45; P less than 0.01) than did any of the serum T parameters or SHBG. The correlation between SaT and hirsutism was partly dependent on the effect of body mass index. After eliminating this effect, SaT still correlated with hair growth on the total body area (rho = 0.36; P less than 0.05). On the basis of the results, SaT seems to relate to the bioavailable fraction of the hormone and, thus, appears to be an optimal method for studying hirsute women.