Is it necessary to measure free testosterone to assess hyperandrogenemia in women? The role of calculated free and bioavailable testosterone.Exp Clin Endocrinol Diabetes. 2006 Apr; 114(4):182-7.EC
Hirsutism in women is defined as excessive facial and/or body terminal hairs showing a masculine distribution; the condition affects approximately 7% of women of reproductive age, and chronic anovulation is a common problem for infertile couples, with a rate of 20-25%. There is a general consensus that these women should be evaluated endocrinologically, as many are found to have an androgen excess (AE) disorder. Free testosterone (FT) is the most prevalent marker in women with androgen excess, but the reference measurement procedures for FT are time-consuming and complex manual procedures that are not routinely practicable in large laboratories. Recently, models have been developed for calculating FT from total testosterone (TT), sex hormone binding globulin (SHBG), and albumin. These calculated values have been found to correlate closely with values estimated using the reference measurement procedures. This study compared measured endocrinological parameters--TT, free testosterone (aFT) by analogue ligand immunoassay method, dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEAS), (SHBG), And calculated parameters--calculated free testosterone (cFT), calculated bioavailable testosterone (cBT), and the free androgen index (FAI) in hirsute women and women with polycystic ovary syndrome (PCOS)--with the values in control individuals. A modified Ferriman-Gallwey score was use to describe the hirsutism pattern. No differences were observed when the measured hormone parameters were compared, while the calculated parameters were significantly increased in women in the hirsutism and PCOS groups in comparison with the values in the control group. Calculate parameters mat be more appropriate markers for assessing hyperandrogenemia in women in comparison with measured values of simple enzyme immuno-assays. These calculated values may be capable of replacing the values estimated using reference measurement procedures, so that time-consuming and complex manual procedures for measuring free testosterone with the reference methods may be dispensable in clinical practice.