Quantificationof 5a- and 5/3-Androstanediolsin Urine by Gas Chromatography-Mass

(Ad) and 5/3-androstane-3a,17/3-diol(/3-Ad)in urine by spe-cificcapillarygas chromatography-massspectrometry,with [16,16,17a-2H3]-5a-androstane-3a,17/3-diol as the internal standard. Comparisonof the so-derivedreference intervals for Ad and /3-Ad in men and women with those previously publishedindicatesa significantpositive biasfor manyof the previous assays in comparison with our procedure.Both Ad and /3-Adhave a pronounceddiurnal rhythm,with maximum excretioninthe interval2300-0700 hours.Concentrationsof Ad and /3-Ad were significantlycorrelated (r = 0.786, p <0.001), butthe ratioof Ad to /3-Adwas notcorrelatedtothat for androsteroneto etiocholanolone,the major 5a and 5/3 metabolitesof androgensin urine. AddItIonal Keyphrases: steroids hirsutism diurnalrhythm reference interval sex- and age-relatedeffects pediatri