Monitoring salivary testosterone and cortisol concentrations across an international sports competition: data comparison using two enzyme immunoassays and two sample preparations

Abstract

Objectives: Salivary testosterone (T) and cortisol (C) concentrations were monitored across a sports competition. Data were compared using two enzyme-immunoassay (EIA) methods and two sample preparations to determine their influence on hormone concentrations.

Design and methods: A group of male athletes (n=19) provided a saliva sample the morning before and one day after (24h post) an international rugby union match. Following an extraction procedure, the samples were analysed for T and C concentrations using a commercial kit (CM(E)) and an in-house method (IH(E)). Raw samples (no extraction procedure) were also tested using the commercial kit (CM(R)).

Results: There were no significant changes in T and C levels from pre to post competition with each EIA method and sample preparation, but significant differences in T (IH(E)>CM(E)>CM(R)) and C (CM(R)>IH(E) and CM(E)) concentrations were seen when both samples were pooled. Bland-Altman analyses confirmed the presence of fixed and proportional bias. Strong and significant correlations were demonstrated between the IH(E) and CM(E) measures of salivary T (r=0.93-0.97) and C (r=0.95-0.97). The T and C values from the raw and extracted samples were also strongly correlated (r=0.93-0.96).

Conclusions: The measurement of salivary T and C concentrations across an international sports event was influenced by different EIA methods and sample preparations, but all measures were strongly correlated with some bias. Both T and C were unresponsive to the sports event, but within the group results large individual variation was seen.