SERUM-FREE TESTOSTERONE IN POLYCYSTIC-OVARY-SYNDROME MEASURED WITH A NEW REFERENCE METHOD

Objective: To quantify the actual serum free T with a specific new ref erence method in women with polycystic ovary syndrome (PCOS) and to an alyze the effects of serum free T, total T, and the T:sex hormone-bind ing globulin (SHBG) ratio on the diagnosis of PCOS. Setting: Outpatien t clinic of reproductive endocrinology at Turku University Central Hos pital, Turku, Finland. Patients: Forty-four oligomenorrheic women with PCOS and 26 weight-matched control women with regular menstrual cycle s. Main Outcome Measures: The concentrations of free T, total T, andro stenedione (A), LH, FSH, SHBG, and insulin in serum. Results: The mean concentrations of free T, total T, A, and LH as well as the LH:FSH an d T:SHBG ratios were higher, whereas the mean concentration of FSH was lower in the women with PCOS than in healthy women. No differences we re found in the free T, total T, or T:SHBG levels or in the body mass indexes (BMIs) between the hirsute (n = 26) and nonhirsute (n = 18) wo men with PCOS. Both elevated free T concentrations and high T:SHBG rat ios were associated with obesity, but serum total T was independent of BMI. The serum free T measurement discriminated PCOS women from contr ols to a similar extent as total T and T:SHBG ratio as judged by a rec eiver operating characteristics analysis. Conclusions: The present dat a indicate that determination of free T provides little additional inf ormation in the diagnosis of hirsutism or PCOS and does not have to be included to the basic evaluation of these patients. Only half of wome n with PCOS exhibited elevated serum free T concentrations.