Response of salivary IL-8 to prolonged and interrupted sitting

Abstract

The effect of prolonged sitting on inflammation, as determined by cytokine profiles, is relatively unexplored. The purpose of this work was to determine the reliability of salivary IL-8 (CXCL8) and the response of IL-8 to prolonged and interrupted sitting. Participants completed two sessions in random order: prolonged sitting (4 hours of sitting) and interrupted sitting (prolonged sitting interrupted every 30 minutes by 3 minutes of walking). Saliva and capillary plasma samples were collected pre- and post-session. Weekly variability in salivary IL-8 and individual responses were also explored. Prolonged sitting increased salivary IL-8 concentrations, while interrupted sitting attenuated this response. Among males, there was no increase in salivary IL-8 during interrupted sitting. Prolonged sitting may serve as a pro-inflammatory stimulus, and movement interruptions may negate this response. Saliva sampling seems to be a reliable method in assessing IL-8 across timepoints within individuals; however, there is high variability across individuals.