title: Autonomic nervous system dysregulation in irritable bowel syndrome.
abstract: BACKGROUND
  Autonomic nervous system (ANS) regulation may be altered in functional diseases, including irritable bowel syndrome (IBS), but published data are not clear to date. The aim of the study was to analyze ANS function in IBS subjects classified by Rome III criteria and healthy controls using standardized technique.
  
  
  METHODS
  ANS activity was evaluated by autoregressive spectral analysis of RR interval and systolic arterial pressure variabilities, to obtain indices of sympatho-vagal modulation of the heart and of spontaneous cardiac baroreflex (α index). A symptom list was used to score 18 somatic complaints (score 0-180) (4SQ). Fatigue and stress were assessed through the use of a global scoring index (0-10).
  
  
  RESULTS
  We enrolled 41 IBS subjects (29 F, age 40 ± 2 years) and 42 healthy matched controls. Heart rate was higher in IBS than control subjects (69 ± 2 vs 61 ± 1; p < 0.001). The total variance of RR interval variability, and α index, were significantly lower in IBS compared to controls (1983.12 ± 384.64 ms(2) vs 4184.55 ± 649.59 ms(2) ; 18.1 ± 2 ms/mmHg vs 29 ± 3 ms/mmHg; p < 0.01). The α index results showed an inverse correlation with stress scores and somatic symptoms.
  
  
  CONCLUSIONS
  IBS subjects display a significant reduction in α index, an established marker of cardiac baroreflex. ANS dysfunction appears to be involved in the pathophysiology of IBS and its assessment may open new perspectives for clinical management of patients suffering from IBS.
authors.affiliation: University of Bologna, Bologna, Italy; Department of Gastroenterology, Humanitas Clinical and Research Center, Rozzano, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Salvioli
authors.forename: G
authors.initials: G
authors.lastname: Pellegatta
authors.forename: M
authors.initials: M
authors.lastname: Malacarne
authors.forename: F
authors.initials: F
authors.lastname: Pace
authors.forename: A
authors.initials: A
authors.lastname: Malesci
authors.forename: M
authors.initials: M
authors.lastname: Pagani
authors.forename: D
authors.initials: D
authors.lastname: Lucini
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000150:complications*; D017704:Baroreflex; D005221:Fatigue / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000294:innervation / Q000503:physiopathology; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications* / Q000503:physiopathology*; D008297:Male; D013315:Stress, Psychological
keywords: autonomic nervous system; irritable bowel syndrome; stress