Relationships among salivary immunoglobulin A, lactoferrin and cortisol in basketball players during a basketball season

The aim of this study was to examine the changes and relationships of immune and stress parameters of basketball players during a basketball season. Eight members of National Taichung University basketball team volunteered to participate. Saliva samples were collected at rest and before the start of practice or competition at seven time points during the intense training, competition and recovery period. Salivary immunoglobulin A (sIgA), cortisol, and lactoferrin were measured during training and competition period and compared with those measured at the fourth recovery week. Relationships among immune and stress parameters were evaluated. Compared with those detected at the fourth recovery week, significant decreases in secretion rates and absolute concentrations of sIgA and lactoferrin were observed at times of intense training and competition. In addition, significant increases in secretion rates and absolute concentrations of salivary cortisol were observed during intense training and competition period and the first week of recovery. Moreover, a significant inverse correlation (r = −0.28; P < 0.05) that existed between secretion rates of sIgA and cortisol as well as a positive correlation (r = 0.32; P < 0.05) that existed between secretion rates of sIgA and lactoferrin was measured. Our results demonstrated that the secreted cortisol was induced and the mucosal immunity of the participants was suppressed during the basketball season. The inverse correlation existed between secretion rates of sIgA and cortisol may indicate a possible role of cortisol in the strenuous exercise-induced immunosuppression. Our results also suggest that a delicate balance may exist between mucosal innate and adaptive immune responses.