Acute And Chronic Effects Of Exercise On Salivary IGA And URTI In Post Menopausal Women

Abstract

Exercise can affect salivary immunoglobulin A (SIgA) responses and may alter a person's susceptibility to upper respiratory tract infections (URTI). However, little is presently known about these effects in post menopausal women which may have reduced SIgA levels because of estrogen deficiency. PURPOSE: This study examined the effects of acute maximal exercise and chronic moderate exercise training on measures of SIgA and the incidence/duration of URTI in post menopausal women. METHODS: Thirty-two post menopausal women were randomized to a 16-week home-based, walking program (5 days/week, 30-min/session, intensity 75% of HRmax) or experimental control group. Before and after the intervention, each subject underwent a maximal exercise treadmill test to determine VO2max and timed, whole unstimulated saliva samples were collected both at rest before and immediately after completion of each VO2max test to determine absolute SIgA concentrations, saliva flow rates (SFR), and SIgA secretion rates (S-SIgA) (Fahlman et al., 2001). In addition, throughout the study duration, each subject completed standard weekly URTI symptomatology research logs. RESULTS: The 16-week walking program resulted in a significant improvement (+10.4%) of VO2max (ml/kg/min) (p<0.01). Repeated measures ANOVA revealed a marked increase (+37.4%) in resting S-SIgA (p0.05), rise (+36.2%) in SFR in the exercise group following training. Independent of study group, both before and after the intervention, resting S-SIgA (-32.3%) and SFR (-29.3%) were noticeably reduced (p<0.01) following acute maximal exercise. Neither VO2max testing nor the moderate intensity training intervention had an effect on absolute SIgA concentrations (p>0.05). Moreover, the number of URTI incidences were the same (control: 4; exercise: 4) and the duration per incidence (control: 5.3±1.5 days; exercise: 6.2±2.2 days) over the 16-week intervention period were similar between study groups (p>0.05). CONCLUSION: These findings in post menopausal women support that S-SIgA and SFR are reduced immediately following maximal exercise. Moreover, a 16-week moderately intense walking program can increase S-SIgA without affecting URTI susceptibility in this population.