Correlation between serum and saliva sex hormones in young female athletes

BACKGROUND: Saliva sampling provides a practical noninvasive way for biological monitoring of steroid hormones but few studies have focused on saliva sex hormones in female athletes, and it is still unknown whether salivary concentrations are an accurate reflection of blood concentrations in this population. The aim of this study was therefore to evaluate the correlation between serum and saliva estradiol (E2) and progesterone (PG) in 10 young female athletes with normal menstrual cycle. METHODS: Thirty blood and saliva samples were taken at rest in a fasting state in order to analyze E2 and PG concentrations, during 3 different hormonal periods: Status 1: low E2 and low PG (end luteal/early follicular); Status 2: high E2 and low PG (end follicular/peri-ovulatory); Status 3: high PG (mid-luteal).<br /> RESULTS: A strong correlation was found between serum and saliva PG (r=0.914, P<0.01), whereas a weaker but still significant relationship was observed between serum and saliva E2 (r=0.755, P<0.01). The most significant correlations obtained for E2 were during Status 2 (r=0.941, P<0.01) and during Status 3 for PG (r=0.817, P<0.01).<br /> CONCLUSIONS: Although it remains challenging to produce precise identification with only saliva samples for each menstrual cycle phase, results seem to show that saliva can provide a convenient substitute to serum for sex hormones in female athletes during longitudinal monitoring. This is of particular interest in this population, with the number of female athletes suffering from an altered menstrual cycle, sometimes even during regular menstruation.