Salivary IgA as a Risk Factor for Upper Respiratory Infections in Elite Professional Athletes

• Autores: Vernon Neville, Michael Gleeson, Jonathan P. Folland
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 40, Nº. 7, 2008, págs. 1228-1236
• Idioma: inglés
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• Dialnet Métricas: 2 Citas
• Resumen

  • The relationship between physiological and psychological stress and immune function is widely recognized; however, there is little evidence to confirm a direct link between depressed immune function and incidence of illness in athletes.

    Purpose: To examine the relationship between salivary immunoglobulin A (s-IgA) and upper respiratory infections (URI) in a cohort of professional athletes over a prolonged period.

    Methods: Thirty-eight elite America's Cup yacht racing athletes were studied over 50 wk of training. Resting, unstimulated saliva samples were collected weekly (38 h after exercise, consistent time of day, fasted) together with clinically confirmed URI, training load, and perceived fatigue rating.

    Results: s-IgA was highly variable within (coefficients of variation [CV] = 48%) and between subjects (CV = 71%). No significant correlation was found between absolute s-IgA concentration and the incidence of URI among athletes (r = 0.11). However, a significant (28%, P < 0.005) reduction in s-IgA occurred during the 3 wk before URI episodes and returned to baseline by 2 wk after a URI. When an athlete did not have, or was not recovering from URI, a s-IgA value lower than 40% of their mean healthy s-IgA concentration indicated a one in two chance of contracting an URI within 3 wk.

    Conclusion: On a group basis, relative s-IgA determined a substantial proportion of the variability in weekly URI incidence. The typical decline in an individual's relative s-IgA over the 3 wk before a URI appears to precede and contribute to URI risk, with the magnitude of the decrease related to the risk of URI, independent of the absolute s-IgA concentration. These findings have important implications for athletes and coaches in identifying periods of high URI risk.