[Female hyperandrogenemia and normal serum levels of testosterone and sex hormone binding globulin].

It is well known that the reference values usually employed for endocrine biochemical measurements are those suggested by the suppliers of commercial kits despite their advice that each laboratory should set its own reference values. Our objectives were to (i) determine reference ranges for serum testosterone (T) and sex hormone binding globulin (SHBG) appropriate to our laboratory and population, and (ii) to analyze their influence on evaluating hyperandrogenemia. SHBG and T were measured, and free and bioavailable testosterone calculated, in (a) 30 selected non-hyperandrogenic women, (b) 87 non-selected healthy female blood donors, (c) 53 women with hyperandrogenism, and (d) 38 women with hyperandrogenic disorders but without biochemical hyperandrogenemia according to normal ranges suggested by the kit manufacturer. Mean serum SHBG concentrations were significantly different among all four groups. SHBG levels were significantly higher in selected normal women (group a). Using our results for this selected control group as new reference values, 12 out of 38 (31.6%) women with hyperandrogenic disorders without apparent hyperandrogenemia (group d) were recategorized as hyperandrogenemic. Similarly, 4 out of 63 (6.4%) non-selected, normal weight, women (group b), were recategorized as hyperandrogenic. Therefore, the diagnosis of hyperandrogenemia would improve accuracy by using customized reference SHBG values instead of those suggested by the suppliers.