Reproducibility of Serum Androgen Concentrations by Liquid Chromatography Mass Spectrometry in Healthy Male and Female Athletes

ABSTRACT Detection of androgen doping relies on mass spectrometry‐based methods to detect natural endogenous and exogenous androgens in urine and serum. To distinguish exogenous administration from natural variation in endogenous serum androgens requires a robust quantitative basis in the variability of serum androgen measurements. The present study therefore aimed to use extensive data from serial antidoping testing of elite male and female athletes to define the reproducibility of serum androgen profiles in male and female athletes. The present study analyzed 5516 samples from 1689 athletes for serum T, DHT, and A4 concentrations and calculated the T/DHT and A4/T ratios from 889 male and 778 female athletes, excluding samples from pregnant, doped, or XY Disorders of Sexual Development (DSD) individuals. As well as the median and interquartile range, the coefficient of variation (CV) and its 95% confidence limits were calculated from three, six, or nine replicate within‐person serum samples (309, 146, and 83 for females and 276, 122, and 65 for males, respectively). Variability was greater for females than males for serum T, DHT, and T/DHT ratio ( p < 10 −6 ) but not significantly different for serum A4 and for A4/T ratio. These data may provide a basis for enhanced detection of T doping and for diagnosis of XY DSD disorders, 5α reductase 2, and 17β hydroxysteroid dehydrogenase 3 deficiencies.