Effects of 12 months of exercise training on salivary secretory IgA levels in elderly subjects

Background: The immune system declines in efficiency with advancing age, making the elderly less resistant to pathogenic microorganisms. Upper respiratory tract infection (URTI) is a common illness. Recent studies have shown that suppression of secretory immunoglobulin A (SIgA) is associated with increased incidence of URTI. Objective: To assess the effect of exercise on salivary SIgA in elderly subjects. Methods: Forty five elderly subjects (18 men, 27 women; mean (SD) age 64.9 (8.4) years) performed both 60 minute resistance and 60 minute moderate endurance training a week for 12 months. Saliva samples were obtained before training, and at four and 12 months during the training period. Salivary SIgA concentrations were measured by enzyme linked immunosorbent assay, and the SIgA secretion rate was calculated. Results: SIgA concentrations before training, and at four and 12 months during training were 24.7 (14.4), 27.2 (14.2), and 33.8 (18.5) μg/ml respectively. SIgA secretion rates were 29.5 (26.0), 33.8 (27.2) and 46.5 (35.1) μg/min respectively. The results indicate that both the concentration and secretion rate of SIgA significantly (p<0.01) increased during 12 months of exercise in these elderly subjects. Conclusion: Regular moderate exercise seems to enhance mucosal immune function in elderly subjects.