Comparison of salivary immunoglobulin A and cortisol levels in competitive and non-competitive child male swimmers

Background: Competitive swimming leads to changes in salivary immunoglobulin A (S-IgA) and cortisol levels. The intensity and duration of exercise cause changes in the immune system. S-IgA and cortisol play a key role in maintaining the body’s immunity. This study was performed to investigate the effect of swimming exercise on the immune and hormonal systems of male children with the same caries index in Zanjan, Iran. Methods: In this cross-sectional study, 86 boys 6–12 years old were selected. Based on their duration of training, the children were divided into two groups of 43: The competitive group and the non-competitive group. The group matching method in terms of dental caries, anxiety, and age was performed in the two groups. Stimulated saliva samples were collected to measure S-IgA and cortisol levels by ELISA before and after the swimming test. Independent t test, paired t test, and chi-square test were used for statistical analysis of data, with the significance level set at P<0.05. Results: The amount of S-IgA was higher in the competitive than in the non-competitive group. After swimming training, S-IgA increased in both age groups (28 children aged 6–9 and 58 aged 9–12 years old). In the 6–9 age group, the amount of cortisol in non-competitive boys increased significantly (P=0.048). In the 9–12 age group, the amount of cortisol in the competitive boys decreased. Conclusion: Based on the findings of this study it seems that swimming can increase the amount of cortisol in the 6-9 age group. However, short-term physical activity (swimming test in this study) could not make a significant difference in the immune and hormonal systems of either of the age groups. Further studies are suggested to provide information on changes in the caries index.