Saliva S100B in professional sportsmen: High levels at resting conditions and increased after vigorous physical activity

BACKGROUND: Neurological dysfunction is a key medical concern in professional sportsmen (PSM). We investigated whether saliva S100B concentrations in PSM and healthy controls are modified before and after training. METHODS: We conducted a case-control-study in 75 patients (25 PSM vs 50 controls) in which S100B saliva concentrations were expressed as absolute values and percentage of change (%) from samples drawn before (T0) and after (T1) training. RESULTS: No differences (P>0.05) between groups were found regarding clinical, monitoring and laboratory parameters. S100B both in PSM and controls was higher at T1 when compared to T0 (P<0.01). In PSM, S100B was higher than controls (P<0.001) at T0 and T1. S100B% at T0-T1 was higher (P<0.001) in PSM and in controls and between PSM and controls (P<0.001). CONCLUSIONS: Increased saliva S100B levels in PSM before and after training suggest a paracrine/autocrine protein's role connected to stressing activity, which becomes especially evident in PSMs.