Background: The limitations of serum testosterone and estradiol (E2) measurements using non-extraction 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 serumtestosterone and E2measurements 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 < 0.001), which was less robust in the hypogonadal range (< 11 nmol/l; R = 0.72, P < 0.001). The IA/MS correlation was weaker in E 2 measurements (R = 0.32, P < 0.001, at E 2 < 40.8 pmol/l, and R = 0.74, P < 0.001, at E 2 > 40.8 pmol/l). Using MS as the comparator method, IA ascertained low test osterone compatible with hypogonadism (< 11 nmol/l),with 75% sensitivity and 96.3% specificity. The same parameters with IA for the detection of low E 2(<40.7 pmol/l) were 13.3 and 99.3%, and for high E 2 (> 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.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism