Immediate and delayed salivary cytokine responses during repeated exposures to Cold Pressor stress.

Introduction Excessive stress is increasingly recognized as an important trigger of many diseases prevalent in modern societies and monitoring such stress related effects could aid prevention. The measurement of salivary markers of inflammation is emerging as a promising tool to non-invasively quantify stress' effects on immune processes in everyday life and thereby detect early aberrations before the manifestation of serious health problems. However, more laboratory-controlled research is needed in order to establish the timescale and determinants of salivary cytokine responses to acute stress. Methods We repeatedly exposed participants to Cold Pressor stress (CPT) or a control procedure and measured a wide array of salivary cytokines as well as subjective, cardiovascular and cortisol stress reactions. CPT exposure was repeated every 15 minutes, 3 times in total, with a duration of 3 minutes each. Saliva was sampled immediately after the first two exposures as well as in 15-minute intervals until 60 minutes after the onset of the first intervention. Results We found that many cytokines were detectable in saliva. Specific stress effects were limited to IL-8 and IL-6, however, which decreased immediately or 15 minutes after stress onset, respectively. Moreover, IL-8 was negatively correlated to cortisol output in the stress but not the control group. Significant increases were also observed in salivary TNF and IFN, however, these effects were similar under both, stress and control conditions. Discussion Our results show that particular salivary cytokines may be sensitive to immediate effects of acute CPT-induced stress and also highlight the importance of employing control procedures to discern stress effects from unrelated variations in salivary cytokines.