Utilization of commercial laboratory results in management of hyperandrogenism in women

To compare results from testosterone radioimmunoassay kits commonly used by commercial laboratories as well as their reference ranges and to analyze the scientific literature for ranges of serum testosterone levels in normal women and those with hyperandrogenism. We reviewed quality assurance reports of various testosterone ligand challenges from four groups of laboratories and summarized testosterone data from 17 published reports about normal women and 14 studies of hyperandrogenic women. A significant variability was demonstrated between the radioimmunoassay kits at all concentrations (for example, a sample with a mean testosterone level of 96.1 ng/dL was reported by some laboratories as containing 71.8 ng/dL and by others as 123.4 ng/dL). All laboratories provide essentially the same "reference range" (approximately 10 to 90 ng/dL) but do not report how the range was established. The scientific literature clearly shows a significant separation in serum testosterone levels between normal (that is, not hyperandrogenic) and hyperandrogenic women. Most hyperandrogenic women had testosterone levels >50 ng/dL, whereas most normal control subjects had levels