Age-dependent reference intervals for measured bioavailable testosterone on the Siemens Advia Centaur: Ethnicity-specific values not necessary for South Asians

ObjectivesTo determine reference intervals for bioavailable testosterone for the Siemens Centaur analyzer and to assess the need for ethnicity-specific ranges for total testosterone and/or bioavailable testosterone in South Asians.Design and methodsTestosterone was measured before and after ammonium sulphate precipitation on specimens collected from a small cohort of healthy male South Asians and Europeans.ResultsInter-ethnicity differences in BioT and TT were not significant. Age-specific BioT reference intervals are reported.ConclusionsEthnicity-specific TT and BioT reference intervals for South Asians do not appear necessary.