Endocrine Abstracts

Introduction: Biological variation (BV) data describe the variability of clinically important measurands around homeostatic set points within subjects (CVI) and between subjects (CVG). The availability of well characterized data enables the interpretation of laboratory results in clinical settings and can also be used to define analytical performance specifications. The aim of this study was to deliver BV estimates for anti-Müllerian hormone (AMH) and androstenedione among women of reproductive age.

Materials and Method: In total, 40 healthy women of reproductive age (19–42 years) were bled for three consecutive menstrual cycles, on the 2^nd or 3^rd day of the cycle. Sera were stored at -80°C before analysis. Analyses for each patient were performed in duplicate within a single run on the Roche Cobas analyser e801 (Roche Diagnostics GmbH, Mannheim, Germany) by electrochemiluminescence immunoassay. The BV estimates with 95% CIs were obtained by CV-ANOVA, after analysis of variance homogeneity and outliers.

Results: The CVI and CVG for AMH were 15.3% and 67.7%, respectively. Analytical variation (CVA) was calculated as 4.6%. The CVI and CVG for androstenedione were 17.9% and 41.2%, respectively. CVA was calculated as 2.1%.

Conclusion: In cycling women, the variability in AMH should be considered by clinicians, especially if a result is close to a clinical cutoff. The serum AMH CVI obtained by this study specifies more stringent analytical performance specifications than previously identified. The added value of this research is the availability of updated BV data, in the case of androstenedione that were not previously published.