Background: Both melatonin and cortisol are hormones with a circadian rhythm secretion associated with sleep regulation, while cortisol has been associated with stress response,
factors which plays an important role in athletes’ preparation for a competition.
Methods: Aiming to characterize athletes’ melatonin and cortisol concentration pre competition and to evaluate if there was correlation between them, in this cross-sectional study,
nine basketball male athletes were assessed. Saliva samples were collected with salivettes® on the night before a competition basketball game (before dinner-BD, and before sleep-BS) and in the
subsequent morning, before the game (immediately after awakening-AA, and after 30 minutes, before breakfast-BB). Cortisol was analyzed in the four moments, while melatonin was analyzed at BD, BS, and
AA. Analysis was conducted using the ELISA method (Salimetrics®, USA and IBL® International GMBH, Germany, respectively for cortisol and melatonin). Data are presented as mean±standard deviation. The
Friedman test, followed by Dunn's post hoc for multiple comparisons were applied to compare values between moments, and the Spearman correlation to identify association between cortisol and melatonin.
Differences were considered significant when p≤0.05.
Results: Athletes characteristics were: 18.4±0.7 years old; 90.7±10.9 kg; 1.93±0.1 m; 24.4±1.5kg/m2 of Body Mass Index; and 10.4±3.2% of body fat percentage. Salivary cortisol
concentration was 2.4±1.7 nmol/L BD; 0.6±0.5 nmol/L BS; 8.5±4.1 nmol/L AA, and 11.5±4.2 nmol/L BB. Statistical differences were observed between BD and BB (p<0,05), and BS was different from AA and BB
(p<0,01). The salivary cortisol concentrations observed are normal with low concentration at night and high concentration at morning. In relation to salivary melatonin concentration, the results were
0.1±0.1 pg/mL BD; 0.2±0.2 pg/ml BS; and 3.0±2.3 pg/mL AA. Significant differences were observed between BD and AA (p<0,01), and BS and AA (p<0,01). Melatonin results at the three collected moments
were lower than the published values for health adults. Exposure to ambient light at the sleeping quarters could not be controlled and may have affected melatonin values. There were no correlations
between salivary cortisol and melatonin in the evaluated moments.
Conclusions: Salivary cortisol pattern was similar to the recommended values for health adults or what was observed in other athletes, while salivary melatonin profile was lower than
published values. More studies are necessary to know and compare the evaluated parameters in athletes.
FINANCIAL SUPPORT: FAPESP (2014/14276-0) and CAPES.