Binding capacity of sex-hormone-binding globulin and free testosterone determination in evaluation of hirsute women.

To investigate the relation between free testosterone (T) and binding capacity of sex-hormone-binding globulin (SHBG-BC) and a degree of hirsutism, 34 women were classified into 3 groups according to the criteria of Ferriman and Gallway on the degree of the hirsutism; 11 patients with a total score of 1 to 3 (group 1), 8 patients with a total score of 4 to 10 (group 2), and 15 patients with a total score of 11 or more (group 3). Total plasma T, SHBG-BC, and free plasma T were measured in each group, and they were compared with those of controls. In groups 1 and 2, mean levels of total T were slightly higher than in controls but the differences were not significant. Total T levels were extremely elevated in group 3. Mean level of SHBG-BC in group 1 was slightly lower than in controls but was not statistically significant. SHBG-BC was drastically reduced in groups 2 and 3. The percent free T levels and free T concentrations were significantly higher than those of controls in groups 2 and 3, but not in group 1. The results suggested that decreased SHBG-BC and increased free T might be the cause of hirsutism in women with normal total T levels.