title: Salivary Alpha-Amylase Correlates with Subjective Heat Pain Perception.
abstract: Self-reports of pain are important for an adequate therapy. This is a problem with patients and infants who are restricted in providing an accurate verbal estimation of their pain. Reliable, real-time, economical, and non-invasive physiological correlates might contribute to a more comprehensive description of pain. Salivary alpha-amylase constitutes one candidate biomarker, which reflects predominantly sympathetic nervous system alterations under stressful conditions and can be measured non-invasively. The current study investigated the effects of acute heat pain on salivary alpha-amylase activity.
  
  
  
  Heat pain tolerance was measured on the non-dominant forearm. Participants completed visual analog scales on pain intensity and unpleasantness. Saliva samples were collected directly after pain induction.
  
  
  
  Twenty-seven healthy volunteers were recruited for this study.
  
  
  
  While salivary alpha-amylase levels correlated positively with intensity and unpleasantness ratings in response to acute heat pain stimuli, there was no corresponding association with pain tolerance.
  
  
  
  Salivary alpha-amylase is suggested to be an indirect physiologic correlate of subjective heat pain perception. Future studies should address the role of salivary alpha-amylase depending on the origin of pain, the concerned tissue, and other pain assessment methods.
authors.affiliation: *Collegium Helveticum, University of Zurich and ETH Zurich, Zurich, Switzerland wittwer@collegium.ethz.ch.
authors.forename: Amrei
authors.initials: A
authors.lastname: Wittwer
authors.affiliation: *Collegium Helveticum, University of Zurich and ETH Zurich, Zurich, Switzerland Brainability LLC, Zurich, Switzerland Department of Psychology, Clinical Psychology and Psychotherapy, University of Basel, Basel, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Krummenacher
authors.affiliation: University of Zurich, Institute of Psychology, Clinical Psychology and Psychotherapy, Zurich, Switzerland.
authors.forename: Roberto
authors.initials: R
authors.lastname: La Marca
authors.affiliation: University of Zurich, Institute of Psychology, Clinical Psychology and Psychotherapy, Zurich, Switzerland.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Ehlert
authors.affiliation: *Collegium Helveticum, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Gerd
authors.initials: G
authors.lastname: Folkers
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D010147:Pain Measurement / Q000379:methods*; D058748:Pain Perception / Q000502:physiology*; D055291:Salivary alpha-Amylases / Q000032:analysis*
chemical_list: D015415:Biomarkers; D055291:Salivary alpha-Amylases
keywords: External; Nonverbal; Pain-Assessment; Salivary Alpha-Amylase; Stress