TY - JOUR
T1 - Total testosterone assays in women with polycystic ovary syndrome
T2 - Precision and correlation with hirsutism
AU - Legro, Richard S.
AU - Schlaff, William D.
AU - Diamond, Michael Peter
AU - Coutifaris, Christos
AU - Casson, Peter R.
AU - Brzyski, Robert G.
AU - Christman, Gregory M.
AU - Trussell, J. C.
AU - Krawetz, Stephen A.
AU - Snyder, Peter J.
AU - Ohl, Dana
AU - Carson, Sandra A.
AU - Steinkampf, Michael P.
AU - Carr, Bruce R.
AU - McGovern, Peter G.
AU - Cataldo, Nicholas A.
AU - Gosman, Gabriella G.
AU - Nestler, John E.
AU - Myers, Evan R.
AU - Santoro, Nanette
AU - Eisenberg, Esther
AU - Zhang, Meizhuo
AU - Zhang, Heping
PY - 2010/12
Y1 - 2010/12
N2 - 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.
AB - 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.
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U2 - 10.1210/jc.2010-1123
DO - 10.1210/jc.2010-1123
M3 - Article
C2 - 20826578
AN - SCOPUS:78650061172
VL - 95
SP - 5305
EP - 5313
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
SN - 0021-972X
IS - 12
ER -