Nelson Vergel
Founder, ExcelMale.com
Comparison of testosterone measurement by the new ‘gold standard’ method liquid chromatography tandem mass spectrometry versus the traditionally in clinical routine used immunoassays in the prediction of symptoms of male hypogonadism
Introduction & Objectives: Recently, liquid chromatography tandem mass spectrometry (LC-MS/MS) has been suggested as the new “gold standard” method that should replace the use of immunoassays (IA) for measurement of serum total testosterone (TT) in diagnosing male hypogonadism (MH) (Rosner et al 2007 JCEM). The LC-MS/MS methodology is more specific than IA; however it is more cost and labor intensive.
Data comparing the predictive value of TT levels measured by these two methodologies in the context of symptoms and metabolic sequelae of MH, are lacking. Therefore, in this study we have compared the predictive values of TT levels measured by LC-MS/MS and IA in relation to metabolic and sexual symptoms associated with MH.
Materials & Methods: Morning blood samples were obtained from 300 fasting men (170 subfertile and 130 controls, the latter identified through the Swedish Population Register) aged 22-48 years, participating in a study on male subfertility and MH. Serum TT levels were measured by both IA (Roche diagnostics two step ElectroChemiLuminescensImmunoassay) and LC-MS/MS, Bland-Altmann plot was applied to estimate the difference between methods.
Furthermore we compared the predictive value of TT levels measured by the two methods in relation to the presence of metabolic syndrome (criteria defined according to the International Diabetes Federation), Insulin resistance (HOMA-ir), decreased libido and erectile dysfunction (the latter 2 outcomes questionnaire based) using ROC analyses.
Results: Twenty-eight of the men (9.3%) presented with TT levels by IA below 8.0 nmol/L, considered as the lower normal threshold of the laboratory. The TT values obtained by IA were, on average, 19.6%, lower than those obtained by LC-MS/MS. The relative difference between the two methods decreased with increasing TT levels in a Bland-Altman plot; 52% of the TT levels obtained using IA were within ±20% of the LC-MS/ MS value. There was no significant difference in the ROC Area Under the Curve (AUC) between the two analytical methods.
Conclusions: As for the prediction of symptoms of MH (the clinical rational for TT measurement) and the presence of metabolic syndrome, those two analytical methods were equal, even though TT levels determined by IA were almost 20% lower than those obtained by LC-MS/MS. Consequently, our findings do not support the recommendation of the Endocrine Society, regarding TT measurement, to replace the widely in routine diagnostic laboratories used IA by the more expensive and labor-intensive LC-MS/MS in routine evaluation for MH.
Czeloth K, Bobjer J, ronton K, et al. P25 – Comparison of testosterone measurement by the new ‘gold standard’ method liquid chromatography tandem mass spectrometry versus the traditionally in clinical routine used immunoassays in the prediction of symptoms of male hypogonadism. European Urology Supplements. 2017;16(13):e3018.
Introduction & Objectives: Recently, liquid chromatography tandem mass spectrometry (LC-MS/MS) has been suggested as the new “gold standard” method that should replace the use of immunoassays (IA) for measurement of serum total testosterone (TT) in diagnosing male hypogonadism (MH) (Rosner et al 2007 JCEM). The LC-MS/MS methodology is more specific than IA; however it is more cost and labor intensive.
Data comparing the predictive value of TT levels measured by these two methodologies in the context of symptoms and metabolic sequelae of MH, are lacking. Therefore, in this study we have compared the predictive values of TT levels measured by LC-MS/MS and IA in relation to metabolic and sexual symptoms associated with MH.
Materials & Methods: Morning blood samples were obtained from 300 fasting men (170 subfertile and 130 controls, the latter identified through the Swedish Population Register) aged 22-48 years, participating in a study on male subfertility and MH. Serum TT levels were measured by both IA (Roche diagnostics two step ElectroChemiLuminescensImmunoassay) and LC-MS/MS, Bland-Altmann plot was applied to estimate the difference between methods.
Furthermore we compared the predictive value of TT levels measured by the two methods in relation to the presence of metabolic syndrome (criteria defined according to the International Diabetes Federation), Insulin resistance (HOMA-ir), decreased libido and erectile dysfunction (the latter 2 outcomes questionnaire based) using ROC analyses.
Results: Twenty-eight of the men (9.3%) presented with TT levels by IA below 8.0 nmol/L, considered as the lower normal threshold of the laboratory. The TT values obtained by IA were, on average, 19.6%, lower than those obtained by LC-MS/MS. The relative difference between the two methods decreased with increasing TT levels in a Bland-Altman plot; 52% of the TT levels obtained using IA were within ±20% of the LC-MS/ MS value. There was no significant difference in the ROC Area Under the Curve (AUC) between the two analytical methods.
Conclusions: As for the prediction of symptoms of MH (the clinical rational for TT measurement) and the presence of metabolic syndrome, those two analytical methods were equal, even though TT levels determined by IA were almost 20% lower than those obtained by LC-MS/MS. Consequently, our findings do not support the recommendation of the Endocrine Society, regarding TT measurement, to replace the widely in routine diagnostic laboratories used IA by the more expensive and labor-intensive LC-MS/MS in routine evaluation for MH.
Czeloth K, Bobjer J, ronton K, et al. P25 – Comparison of testosterone measurement by the new ‘gold standard’ method liquid chromatography tandem mass spectrometry versus the traditionally in clinical routine used immunoassays in the prediction of symptoms of male hypogonadism. European Urology Supplements. 2017;16(13):e3018.
