title: Women with diarrhoea-predominant irritable bowel syndrome show an increased pressure response to 35% carbon dioxide stress challenge.
abstract: The responses to inhalation of 35% carbon dioxide (CO(2)) as a stressor were compared in female irritable bowel syndrome (IBS) patients and healthy controls to assess potential differences in cardiovascular, neuroendocrine and behavioural responses to stress. A total of 22 women (12 patients with ROME II defined diarrhoea-predominant IBS and 10 aged-matched controls) were challenged with a single vital capacity breath of 35% CO(2) (with 65% oxygen). Beat-to-beat blood pressure and heart rate were recorded prior to, during and after the inhalation. Serum cortisol concentration and behavioural ratings were measured pre- and post-inhalation. A typical pattern of responses to CO(2) was observed, characterised by a reduction in heart rate and increases in serum cortisol and anxiogenic symptoms; however, these responses did not differ between groups. Both groups also demonstrated an increase in systolic blood pressure; however, this response was significantly enhanced in IBS patients compared to healthy controls (P < 0.05). These findings demonstrate that females with diarrhoea-predominant IBS have an exaggerated pressor response to 35% CO(2) stress challenge, suggesting a more stress-responsive sympathetic nervous system.
authors.affiliation: Clinical Science at South Bristol, University of Bristol, Bristol, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Shufflebotham
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wetherell
authors.forename: Dana
authors.initials: D
authors.lastname: Hince
authors.forename: Sean
authors.initials: S
authors.lastname: Hood
authors.forename: Stafford
authors.initials: S
authors.lastname: Lightman
authors.forename: David
authors.initials: D
authors.lastname: Nutt
authors.forename: Christopher
authors.initials: C
authors.lastname: Probert
authors.forename: John
authors.initials: J
authors.lastname: Potokar
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D001007:Anxiety / Q000139:chemically induced; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000008:administration & dosage*; D003967:Diarrhea / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D043183:Irritable Bowel Syndrome / Q000097:blood / Q000503:physiopathology*; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology*
chemical_list: D002245:Carbon Dioxide; D006854:Hydrocortisone