A simple and objective marker for stress.

Objective: To examine the association between pressure pain sensitivity (PPS) at sternum and various well established physiological stress measures among opera singers during a performance as a measure for transitional stress, and resting values in out-clinic patients as a measure for persistent stress. Methods: Changes in PPS on the index finger and sternum, middle blood pressure (MAP), heart rate (HR), pressure-rate-product (PRP) and salivary cortisol (SCO) were recorded in 26 opera solo singers during a performance. Resting PPS, HR, MAP, PRP and presence of a noxious withdrawal reflex (NWR) were recorded in 181 out-clinic patients. Results: During opera performance, the PPS on sternum changed concomitantly with MAP (correlation coefficient (r) r=0.42, p0.005), HR (r=0.55, p0.001), PRP (r=0.54, p0.001) and SCO (r=0.26, p=0.066). During rest, a significant correlation was found between PPS on sternum and HR, PRP and presence of noxious withdrawal reflex (all p0.01). Conclusions: The PPS measurement at sternum was associated with well established physiological stress measures and may represent a simple, objective and reliable measure of physiological stress used by both non-professional and professionals.