Comparison of serum testosterone and estradiol measurements in 3174 European men using platform immunoassay and mass spectrometry; relevance for the diagnostics in aging men.

Background: The limitations of serum testosterone and estradiol (E-2) measurements using nonextraction platform immunoassays (IAs) are widely recognized. Switching to more specific mass spectrometry (MS)-based methods has been advocated, but directly comparative data on the two methods are scarce. Methods: We compared serum testosterone and E-2 measurements in a large sample of middle-aged/elderly men using a common platform IA and a gas chromatography (GC)-MS method, in order to assess their limitations and advantages, and to diagnose male hypogonadism. Of subjects from the European Male Aging Study (n = 3174; age 40-79 years), peripheral serum testosterone and E-2 were analyzed using established commercial platform IAs (Roche Diagnostics E170) and in-house GC MS methods. Results: Over a broad concentration range, serum testosterone concentration measured by IA and MS showed high correlation (R=0.93, P 40.8 pmol/l). Using MS as the comparator method, IA ascertained low testosterone compatible with hypogonadism ( 120 pmol/l) 88.4 and 88.6%. Conclusion: A validated platform IA is sufficient to detect subnormal testosterone concentrations in the diagnosis of male hypogonadism. The IA used for E-2 measurements showed poor correlation with MS and may only be suitable for the detection of high E-2 in men. (Less)