Effects of the Menstrual Cycle and Acute Aerobic Exercise on Cytokine Levels

Objective: The purposes of this study were: 1) to investigate the effects of menstrual cycle on the basal levels of salivary cytokines (interleukin IL-6 and IL-8) in young healthy women; 2) to examine the influences of prolonged aerobic exercise at ventilatory threshold (VT) on salivary and circulating IL-6 and IL-8 concentrations during menstrual phase. Methods: Eight healthy women participated in three visits (saliva sampling during menstrual, follicular and luteal phases) and two trials (exercise and resting trials during a separate menstrual phase). The exercise trial involved a 60- min cycling at VT and the resting trial involved resting for 90 min.Saliva and blood samples were taken at before, immediately after and 30 min post-exercise and equivalent times during the resting trial. Results: Salivary IL-6 level was higher during the follicular phase than the luteal phase at rest. Salivary IL-8 immediately post-exercise was higher than pre-exercise, and circulating IL-6 was significantly increased from pre-exercise to immediately post-exercise and 30 min post exercise. Conclusion: The results showed that salivary cytokines are influenced by menstrual cycle and prolonged exercise during menstrual phase.However the levels of IL-6 and IL-8 in saliva do not closely reflect those in plasma, and therefore might reflect a local level of inflammation.