A simple and objective marker for stress

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.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.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).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.