All of the PCOS theca preparations studied came from ovaries of women with fewer than six menstrual periods per year and elevated serum total testosterone (T) or bioavailable T levels, as we previously described (26).
In our study we measured total but not free or bioavailable estradiol concentration, while these fractions of estradiol in other studies were directly related to testosterone concentrations in T2DM.
Men treated with simvastatin did not have significantly different total, bioavailable, or free testosterone, estradiol, or SHBG levels than untreated men (Fig. 1 and Table 1).
Estradiol and testosterone assays have not been very sensitive nor accurate in the lower ranges, while both hormones bind to SHBG, so total values may not be as informative as 'free' or bioavailable hormone [ 4].
SHBG, and thus total testosterone levels, vary widely based on genetic, metabolic and endocrine influences, and it is now accepted that measurement of free or bioavailable testosterone predicts androgenic effects more accurately than total testosterone levels [ 4].
Total testosterone (TT) is frequently prescribed with an SHBG and/or free or bioavailable testosterone measurement.
It is now accepted that measurements of free or bioavailable testosterone predicts androgenic effects more accurately than total testosterone levels.
The measurement of free or bioavailable testosterone should be considered when the serum total testosterone concentration is not diagnostic of hypogonadism, particularly in obese men.
