Urinary steroid profile in relation to the menstrual cycle

Abstract

The interpretation of the steroidal module of the Athlete Biological Passport (ABP) in female athletes is complex due to the large variation of the endogenous urinary steroids. The menstrual cycle seems to be one of the largest confounders of the steroid profile. The duration of the different phases in the menstrual cycle differs between women and is difficult to predict only by counting days after menstruation. Here, we have determined the follicle, ovulation, and luteal phases, by assessing the menstrual hormones in serum samples collected from 17 healthy women with regular menses. Urine samples were collected three times per week during two consecutive cycles to measure the urinary steroid concentrations used in the ABP. The metabolite that was mostly affected by the menstrual phases was epitestosterone (E), where the median concentration was 133% higher in the ovulation phase compared to the follicle phase (p < 0.0001). The women with a large coefficient of variation (CV) in their first cycle also had a large CV in their second cycle and vice versa. The inter‐individual difference was extensive with a range of 11%–230% difference between the lowest and the highest T/E ratio during a cycle. In conclusion, E and ratios with E as denominator are problematic biomarkers for doping in female athletes. The timing of the sample collection in the menstrual cycle will have a large influence on the steroid profile. The results of this study highlight the need to find additional biomarkers for T doping in females.

Urinary Steroid Profile in Elite Female Athletes in Relation to Serum Androgens and in Comparison With Untrained Controls

“…The monitoring of serum T may increase the likelihood to detect T intake in female athletes as serum T is superior compared to the urinary steroid profile ( Handelsman and Bermon, 2019 ; Börjesson et al, 2020 ; Knutsson et al, 2020 ). Our correlations between the urinary ABP metabolites and serum hormones are in agreement with previously published data ( Knutsson et al, 2020 ; Schulze et al, 2020 ).…”

“…For example, urinary E is at the highest concentrations in the luteal phase, whereas the other ABP metabolites show minor fluctuations during a menstrual cycle. These variations result in larger individual ABP-thresholds in women ( Schulze et al, 2020 ). Other challenges associated with ABP interpretation in female athletes include the use of hormonal contraceptives (HC) ( Schulze et al, 2014 ; Ekström et al, 2019 ), and the impact of genetic polymorphisms in UDP-glucuronosyltransferases (UGTs), such as UGT2B17 ( Schulze et al, 2014 ).…”

The Specificities of Elite Female Athletes: A Multidisciplinary Approach

“…Mareck-Engelke et al [ 409 , 410 ] performed the first studies in female subjects and established that one of the most sensitive markers, the T/E ratio, was significantly dependent on MC. This observation was more recently confirmed by other authors [ 411 , 412 ], who studied urinary steroid profiles throughout the MC in healthy female volunteers and concluded that E was one of the biomarkers that fluctuated the most. In addition, Schulze et al [ 412 ] established that T and its metabolites exhibited higher concentrations in PeO, with similar variations over two consecutive MCs, but inter-individual variations remained very high.…”

“…This observation was more recently confirmed by other authors [ 411 , 412 ], who studied urinary steroid profiles throughout the MC in healthy female volunteers and concluded that E was one of the biomarkers that fluctuated the most. In addition, Schulze et al [ 412 ] established that T and its metabolites exhibited higher concentrations in PeO, with similar variations over two consecutive MCs, but inter-individual variations remained very high. Recently, Mullen et al [ 413 ] demonstrated that the variability of the ABP biomarkers in Swedish and Norwegian athletes was higher in females compared to males.…”

Current Insights into the Steroidal Module of the Athlete Biological Passport

“…While these results underline the added value of including 5αADIOL/E into the steroid profile of athletes' doping controls, it should be mentioned that this ratio may exhibit a larger variability compared to other urinary steroid ratios, especially concerning urine samples from females. This effect has also been recognized for the T/E and can be attributed to the menstrual cycle, hormonal contraceptives, and general analytical challenges caused by the lower concentrations of urinary steroids in urine samples collected from females [32][33][34][35][36]. Carefully considering these confounding factors where applicable will help to avoid unnecessary confirma-tion procedures by simultaneously maintaining the high probative force of the steroidal module.…”