Role of serum androgens and sex hormone binding globulin capacity in the evaluation of hirsutism in women.

Serum samples from 23 hirsute women and 23 non-hirsute women matched for age and deviation from ideal weight were analyzed for total testosterone (T), percent free testosterone (% FT) and sex hormone binding globulin capacity (SHBG). The % FT was assayed by 2 methods, using diluted serum in equilibrium dialysis (EQD) and using undiluted serum in centrifugal ultra-filtration (UF). SHBG was measured by a DEAE cellulose filter assay and T by radioimmunoassay. The two methods for determining % FT correlated well. There was considerable overlap between the hirsute and control groups for all of the measured parameters. The discrimination between the 2 groups provided by the indirect estimate of free testosterone obtained from the ratio of T to SHBG was at least as good as that provided by the free testosterone derived from ultrafiltration or dialysis.