Salivary Levels of Immunoglobulin A in triathletes During an Endurance Repeated Exercise.

Abstract

Introduction One of the components of immune system that is affected by strenous physical exercise is the excretion of saliva immunoglobulin A (sIgA). Streetenberg et al. (1997) have reported that sIgA flow rate and total output were reduced in triathletes following an Olympic distance triathlon. It has been also suggested that sIgA concentrations may decrease over prolonged periods of intensive training in elite athletes (Gleeson et al. 1999). The purpose of this study was to assess salivary IgA secretion, as a biomarker for mucosal defences, in a selection of triathletes before and immediately after a race and the relationship between changes in sIgA and repetition of 6 different trials. Methods In order to study the salivary immunoglobulin A (IgAs) changes after and during an endurance-repeated exercise, 8 elite triathletes were studied during a 6 day-competition, the France Iron Tour (F.I.T.). This competition constituted of 6 different trials. Salivary samples were collected to determine IgAs flow 3 times per day: the morning at basal state, 10 minutes before the race and immediately after the race. IgAs measurements were made using a sandwich enzyme-linked immunosorbent assay (ELISA). A blood sample was collected on day 1 and day 6 to look for dehydration. Results Our results showed a significant decrease of IgAs flow rate higher in post-race versus pre-race (P <0.05) and in IgAs daily flow throughout the F.I.T(P <0.05) (fig. 1). Blood samples showed a hemodilution and a significant decrease in white blood cells (P <0.05) (Table 1).Table 1: Bloods parameters on day 1 and on day 6 (basal state). *P <0.05.Figure 1: sIgA daily flow rate, #P <0.05Discussion Our study showed a IgA flow rate decrease after each race as it's show by several authors in independents exercises but we also showed a decrease of mean salivary flow rate per day all along the 6 days. We can think that the 6 times races repetition could have an effect in immunity parameters and the white blood cell very low level on day 6 whether in day 1 (4,50 to 1,90 103/μl) show the same effect. The effect and the incidence of reduced amounts of sIgA has been shown after high-intensity training or races (Nieman and al. 1996, Gleeson and al. 1999). The more often report are the U.R.T.I. (upper tract respiratory infection) but the real incidence of these diseases on athletes performances were not clearly shown. In conclusion this study suggest that an endurance-repeated exercise performed by trained athletes may induce immuno-alterations contribute to increase the risk of URTI. A close monitoring of training and immunological parameters may be interesting to have sharp vision of exercise incidence on immunity.