Total testosterone assays in women with polycystic ovary syndrome: precision and correlation with hirsutism.

Published

Journal Article

CONTEXT: There is no standardized assay of testosterone in women. Liquid chromatography mass spectrometry (LC/MS) has been proposed as the preferable assay by an Endocrine Society Position Statement. OBJECTIVE: The aim was to compare assay results from a direct RIA with two LC/MS. DESIGN AND SETTING: We conducted a blinded laboratory study including masked duplicate samples at three laboratories--two academic (University of Virginia, RIA; and Mayo Clinic, LC/MS) and one commercial (Quest, LC/MS). PARTICIPANTS AND INTERVENTIONS: Baseline testosterone levels from 596 women with PCOS who participated in a large, multicenter, randomized controlled infertility trial performed at academic health centers in the United States were run by varying assays, and results were compared. MAIN OUTCOME MEASURE: We measured assay precision and correlation and baseline Ferriman-Gallwey hirsutism scores. RESULTS: Median testosterone levels were highest with RIA. The correlations between the blinded samples that were run in duplicate were comparable. The correlation coefficient (CC) between LC/MS at Quest and Mayo was 0.83 [95% confidence interval (CI), 0.80-0.85], between RIA and LC/MS at Mayo was 0.79 (95% CI, 0.76-0.82), and between RIA and LC/MS at Quest was 0.67 (95% CI, 0.63-0.72). Interassay variation was highest at the lower levels of total testosterone (≤50 ng/dl). The CC for Quest LC/MS was significantly different from those derived from the other assays. We found similar correlations between total testosterone levels and hirsutism score with the RIA (CC=0.24), LC/MS at Mayo (CC=0.15), or Quest (CC=0.17). CONCLUSIONS: A testosterone RIA is comparable to LC/MS assays. There is significant variability between LC/MS assays and poor precision with all assays at low testosterone levels.

Full Text

Duke Authors

Cited Authors

  • Legro, RS; Schlaff, WD; Diamond, MP; Coutifaris, C; Casson, PR; Brzyski, RG; Christman, GM; Trussell, JC; Krawetz, SA; Snyder, PJ; Ohl, D; Carson, SA; Steinkampf, MP; Carr, BR; McGovern, PG; Cataldo, NA; Gosman, GG; Nestler, JE; Myers, ER; Santoro, N; Eisenberg, E; Zhang, M; Zhang, H; Reproductive Medicine Network,

Published Date

  • December 2010

Published In

Volume / Issue

  • 95 / 12

Start / End Page

  • 5305 - 5313

PubMed ID

  • 20826578

Pubmed Central ID

  • 20826578

Electronic International Standard Serial Number (EISSN)

  • 1945-7197

Digital Object Identifier (DOI)

  • 10.1210/jc.2010-1123

Language

  • eng

Conference Location

  • United States