Background and aims: Pain perception can be influenced by several factors, including stress. Stress can have various reactions on pain perception and this depends on various factors. The aim of the current study was to determine the effect of acute stress on mechanical hyperalgesia, endogenous pain inhibition and bottom-up excitability of pain in healthy people and to determine which factors are responsible for this stress-effect.
Methods: 101 Healthy pain-free participants underwent a modified Trier Social Stress Test. Pre- and post-stress, pressure pain thresholds (PPT), conditioned pain modulation (CPM) efficacy and temporal summation (TS) were determined in the mm. trapezius and quadriceps. Furthermore, 7 questionnaires were completed: a general questionnaire, the LDI, LTE, IPAQ-sf, PCS, PVAQ and FPQ-9 .
Results: We found a significant stress-effect on pain perception, with an increase of PPT and a decrease in CPM efficacy (p<.001). No effect was found in TS. Factors associated with the stress-effect were age, previous surgery, focus on the cuff, FPQ score and IPAQ in METs.
Conclusions: The increase in PPT was not a clinical change, while the decrease in CPM was meaningful. None of the factors predicted the stress-effect in all experimental pain measurements and only for a small proportion.

THE EFFECT OF PSYCHOLOGICAL STRESS ON PAIN SENSITIVITY IN HEALTHY PEOPLE