The comparison of free androgen index and serum free testosterone levels in women with hirsutism or polycystic ovary syndrome

Objectives: In many laboratories free testosterone can not be measured, so that free androgen index is suggested in-stead. The aim of this study was to compare free androgen index and serum free testosterone levels measured by ra-dioimmunoassay in women with hirsutism or polycystic ovary syndrome. Materials and methods: Totally 94 women referred to the polyclinics of Ankara Numune Hospital were retrospectively included. Three patient groups were composed; 55 of hirsutism, 20 of polycystic ovary syndrome and 19 of both hirsutism and polycystic ovary syndrome. Total testosterone and sex hormone binding globuline levels were measured by chemiluminescence method and free testosterone levels were measured by radioimmunoassay. Free androgen index was calculated from total testosterone and sex hormone binding globuline. Results: There was a significant positive correlation between free testosterone and free androgen index in patients with hirsutism, in patients with polycystic ovary syndrome, in patients with hirsutism and polycystic ovary syndrome, and in total patient group [r(hirsutism)=0,597, r(PCOS)=0,617, r(hirsutism and PCOS)=0,779, r(total patient group)=0,649, P<0,01]. Receiver operating characteristics curves were drawn to assess the diagnostic power of parameters for all patient groups [For hirsutism (n=55) auROC (FT)=0,431 auROC (FAI)=0,485] [For PCOS (n=20) auROC (FT)=0,431 auROC (FAI)=0,359] [For hirsutism and PCOS (n=19) auROC (FT)=0,676 auROC (FAI)=0,669]. In our study, free testosterone and free androgen index were found useful to diagnose ‘hirsutism and polycystic ovary syndrome' but not others. Conclusion: Free androgen index can be used instead of free testosterone in hirsutism and polycystic ovary syndrome for diagnosis.