Stability of the alternative steroid profile and stereodomic model : Part II – Evaluation of female steroid profiles : influences of contraceptives and pregnancy

In the past years, the detection of misuse with endogenous steroids has evolved. New metabolites that improve the detection of misuse with endogenous steroids have been introduced with extended steroid profiling. Also the developments of an adaptive Bayesian model for systematic longitudinal follow-up of steroid profile parameters and a steroidomic model that recognizes abnormal steroid profiles have shown to be able to boost the detection sensitivity of modern steroids profiling. Until now, these new markers and technologies have not been evaluated yet with the steroid profiles of females. The stability of female steroid profiles was reinvestigated with regards to the minor steroid metabolites, the steroidomic model and adaptive model from the steroid passport. In addition, the influence of oral contraceptives and pregnancy was studied using these technologies. Introduction Throughout the last decades, steroid profiling has been studied and became an established tool to screen for misuse with endogenous steroids. Recently, several biomarkers including minor hydroxylated steroids were introduced to increase the steroid profiling specificity [1]. The combination of these additional metabolites and the traditional markers with the longitudinal model as used in the biological passport and a discriminative algorithm resulted in a very doping-sensitive steroidomic model [2]. This model facilitates the interpretation of all monitored biomarkers by reducing them to a single abnormal steroid profile score. These new strategies however were elaborated using male steroid profiles. As the endocrine system of females differs from those of men, these new markers should be investigated onto female steroid profiles. During the menstrual cycle the female endocrine system shows very large intra-individual variances of progestogens and estrogens, the female hormones which are in close relation with those of their androgenic steroid profile. There is close interaction of the female hormones with secretagogues follicle stimulating hormone (FSH) and luteinizing hormone (LH) that might influence androgen levels and its metabolites. A normal menstrual cycle starts with the follicular phase where the FSH induced maturing of a follicle takes place. This follicle produces estradiol, which in turn suppresses FSH. A sufficient concentration of estradiol triggers an acute production of LH in pituitary, inducing the ovulation. After ovulation and during the luteal phase, the follicle becomes a corpus luteum which is stimulated by LH. The corpus luteum produces progesterone, which inhibits LH production by feedback. Progesterone concentrations drop inducing the menstruation. The close relation of the involved secretagogues LH and FSH and progesterone as androgen precursor is shown in Figure 1. Female endocrine fluctuation causes certain alterations in the steroid profile as we monitor. Often pregnanediol (PD), a progesterone metabolite is also monitored as an endogenous reference compound for IRMS. Often, these natural infradian rhythms are suppressed by hormonal birth control pills. These oral contraceptives usually consist of a combination of estrogen, usually ethinyl estradiol and progesterone derivatives in different concentrations depending on the type of contraceptive pill. These synthetic analogs inhibit the production of the secretagogues LH and FSH and prevent maturing of the follicle. Other large changes in the female endocrine system occur during an emerging pregnancy where human chorionic gonadotropine (hCG) is released by the syncytiotrophoblast which forms the placenta in later stages of the pregnancy. Hence, this study contributes to the information and experience needed to correctly interpret these new markers and steroidomic model as well as traditional steroid profile markers in female athletes with a focus on the influence of the menstrual cycle, hormonal contraceptives and pregnancy.