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
N1 - Funding Information:
This work was supported by National Institutes of Health (NIH)/Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Grants U10 HD27049 (to C.C.), U10 HD38992 (to R.S.L.), U10HD055925 (to H.Z. and M.Z.), U01 HD38997 (to E.R.M.), U10 HD39005 (to M.P.D.), U10 HD27011 (to S.A.C.), U10 HD33172 (to M.P.S.), U10 HD38988 (to B.R.C.), U10 HD38998 (to W.D.S.), U10 HD38999 (to P.M.G.), U10 HD055936 (to G.M.C.), U10 HD055942 (to R.G.B.), and U10 HD055944 (to P.R.C.); U54-HD29834 (to the University of Virginia Center for Research in Reproduction Ligand Assay and Analysis Core of the Specialized Cooperative Centers Program in Reproduction and Infertility Research); General Clinical Research Center Grants MO1RR00056 (to the University of Pittsburgh) and MO1RR10732 and construction grant C06 RR016499 (to Pennsylvania State University). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NICHD or NIH.
Funding Information:
The strengths of our study include the blinding, both of the study design and of the masking of the duplicate samples. Blinding is essential in eliminating selection bias in clinical trials, yet only rarely is it ever applied to assay validation studies. In clinical chemistry studies, participating laboratories are often alerted to the purpose of the study and/or their identity is protected by anonymous label in resulting publications (5, 7) . Furthermore, we used human serum from a clinical study, rather than a mass-produced laboratory standard or a pooled human standard to perform this study and linked it to phenotypic data that have been linked with increased circulating androgen levels. We compared two methods of LC/MS with an RIA, whereas previous studies have used a single method of MS, usually GC/MS, as the standard (5, 7) or have compared immunoassays with LC/MS as the standard (2, 6) . Thus, our study reflects the current clinical reality where there is no widely available validated testosterone assay. This is a situation that is not fully comprehended by most clinicians and many researchers in the field who assume that all MS assays are comparable. Our sample size was robust and the largest study to date examining quality control of total testosterone serum levels in women. Finally, our women were well characterized for PCOS, are the result of a multicenter study, and thus more representative of the U.S. population than a single-center study. Our study was also supported solely by National Institutes of Health funding without industry support (5, 7) .
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
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 -