Conditioned pain modulation in women with irritable bowel syndrome.
Evidence suggests that patients with irritable bowel syndrome (IBS) are more vigilant to pain-associated stimuli. The aims of this study were to compare women with IBS (n = 20) to healthy control (HC, n = 20) women on pain sensitivity, conditioned pain modulation (CPM) efficiency, and salivary cortisol levels before and after the CPM test and to examine the relationship of CPM efficiency with gastrointestinal pain, somatic pain, psychological distress symptoms, and salivary cortisol levels in each group. Women, aged 20-42 years, gave consent, completed questionnaires, and kept a symptom diary for 2 weeks. CPM efficiency was tested with a heat test stimulus and cold water condition stimulus in a laboratory between 8 and 10 a.m. on a follicular phase day. Salivary cortisol samples were collected just before and after the experimental testing. Compared to the HC group, women with IBS reported more days with gastrointestinal and somatic pain/discomfort, psychological distress, fatigue, and feeling stressed. During the CPM baseline testing, women with IBS reported greater pain sensitivity compared to the HC group. There was no significant group difference in salivary cortisol levels nor in CPM efficiency, though a post-hoc analysis showed a higher prevalence of impaired CPM efficiency among IBS subjects with more severe lower-GI symptoms. In the IBS group, reduced CPM efficiency was associated with daily abdominal pain/discomfort and psychological distress. Overall, women with IBS exhibited an increased sensitivity to thermal stimuli. Impaired CPM was present in a subset of women with IBS.
Department of Biobehavioral Nursing and Health Systems, University of Washington, Seattle, WA, USA jarrett@uw.edu.
Monica E
ME
Jarrett
Department of Pediatrics, Children's Nutrition Research Center, Houston, TX, USA Baylor College of Medicine, Texas Children's Hospital, Houston, TX, USA.
Robert J
RJ
Shulman
Department of Biostatistics and Office of Nursing Research, University of Washington, Seattle, WA, USA.
Kevin C
KC
Cain
Department of Biobehavioral Nursing and Health Systems, University of Washington, Seattle, WA, USA.
Wimon
W
Deechakawan
Department of Biobehavioral Nursing and Health Systems, University of Washington, Seattle, WA, USA.
Lynne T
LT
Smith
Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA.
Philippe
P
Richebé
Pacific Medical Center, Seattle, WA, USA.
Margaret
M
Eugenio
Department of Biobehavioral Nursing and Health Systems, University of Washington, Seattle, WA, USA.
Margaret M
MM
Heitkemper
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications*; D008875:Middle Aged; D010146:Pain / Q000209:etiology*; D059408:Pain Management / Q000379:methods*; D017288:Pain Threshold; D055815:Young Adult
conditioned pain modulation; cortisol; female; irritable bowel syndrome