Biological and psychological predictors of visceral pain sensitivity in healthy women

Abstract

Whereas psychological, immunological and HPA-axis related factors have been implicated in pain sensitivity in several pain models, insight into the mechanisms of visceral pain sensitivity is still limited. The current study aimed to investigate psychological and biological predictors of visceral pain sensitivity in healthy subjects. In N = 59 healthy females, measures of gastrointestinal (GI) symptoms in daily life, trait and state anxiety, depression, serum cortisol, and serum levels of interleukin (IL)-6 were obtained, followed by assessment of rectal distension pain sensitivity measures (i.e. rectal distension sensory threshold, pain threshold, and pain ratings for discrete rectal distension stimuli at pain threshold level). Regression analyses revealed that more GI symptoms in daily life predicted lower sensory thresholds. Further, lower pain thresholds were predicted by increased GI symptoms, higher state anxiety and cortisol concentrations, whereas increased cortisol was also associated with lower pain ratings. IL-6 was positively related to GI symptoms and negatively to the pain threshold, but was a non-significant predictor of pain thresholds in the multiple regression analysis. Similar to findings in patients with functional GI symptoms, we showed that subclinical GI symptoms predict visceral pain sensitivity. In line with somatic pain findings, state but not trait anxiety was found to predict visceral pain sensitivity. Our findings on serum cortisol as predictor point to a differential effect of cortisol on the different aspects of pain sensitivity. Our finding on the role of IL-6 in GI symptoms and pain sensitivity is promising for understanding gastrointestinal complaints in patients and needs further investigation.