Heart Rate Variability in Patients With Irritable Bowel Syndrome Before and After Gut-directed Hypnotherapy
Condition: Irritable Bowel Syndrome
MeSH terms: Irritable Bowel Syndrome; Syndrome
Study type: Interventional

Summary: 
      Dysregulation of the brain-gut-axis is believed to underlie symptom generation in irritable
      bowel syndrome (IBS). The Autonomous Nervous System (ANS) is an important route of brain-gut
      communication and aberrant ANS functioning, reflected in abnormalities in Heart Rate
      Variability (HRV) have been described in IBS. Gut-directed hypnotherapy (GHT) leads to
      symptom reductions in IBS and is supposed to increase parasympathetic regulation. To date,
      however, the role of therapeutic modulation of the ANS through GHT has been rarely examined.
      Aim of this pilot study is therefore to assess the impact of GHT on ANS functioning as
      reflected in heart rate variability. 24h-electrocardiogram before and after 10 sessions of
      gut-directed hypnotherapy will be administered in groups. Time and Frequency measures of
      Heart Rate Variability (HRV) will be extracted from 24h-electrocardiogram protocols as
      indicators of ANS regulation. Validated questionnaires will be utilized to assess IBS
      symptoms (IBS-SSS) and psychological distress (HADS-D).
    

Detailed description: 
      Background. The autonomous nervous system (ANS) is a key substrate for the regulation of
      gastrointestinal homeostasis and plays a substantial role in the pathophysiology of IBS. A
      convincing amount of evidence indicates a relationship between specific patterns of disturbed
      sympathovagal balance, symptom severity, and IBS subtypes. According to the literature,
      hypnosis affects sympathovagal balance by inducing elevated parasympathetic nervous system
      activity and reduced sympathetic tone. Previous studies reported clinical improvements of
      IBS-symptoms after successful Gut-directed group Hypnotherapy (GHT) over long-term periods
      but rarely depicted the underlying alterations in ANS regulation.

      Aims of the study. The aim of this study is to investigate short- and long-term effects of
      Gut- directed group Hypnotherapy (GHT) on ANS regulation in refractory IBS-subjects, measured
      by heart rate variability. We further attempt to reveal differences in effects of GHT
      treatment on ANS regulation between IBS-subtypes (constipation-predominant vs.
      diarrheapredominant) and examine the relationship between self-rated hypnotic depth and
      parasympathetic activity. Methods. Within a period of 29 months, a sample of N=50 consecutive
      IBS-patients receive GHT treatment (7-10 weekly sessions) at the Psychosomatic Out-patient
      Clinic, Division of Gastroenterology and Hepatology, University Hospital of Vienna.
      Alterations in heart rate variability (HRV) are extracted by Electrocardiogram (ECG)
      recording in supine (30 min), sitting (10 min) and standing (10 min) position. HRV indices of
      sympathetic and parasympathetic control are quantified by using measures from time and
      frequency domains. Assessment of psychological variables is carried out by standardized
      questionnaires: anxiety, depression, stress, resilience, quality of life and IBS symptom
      burden.

      Methods. Recordings of heart rate and R-R intervals will be conducted continuously for 24
      hours. Electrocardiogram (ECG) recordings will be performed within one week before the first
      and after the last session of hypnosis. Patients will previously informed about the practical
      requirements for the recordings as well as the role of heart rate variability for health and
      the presumed associations between Autonomous Nervous System function, psychological stress
      reactivity patterns and digestive function. Recording devices will be mounted and activated
      at the hospital. Patients will return to their home or work environment and will be
      instructed not to ingest stimulating drinks (such as coffee, energy drinks), alcohol and not
      to engage in physical exercises during the whole recording time. Patients will return to the
      hospital >24h later for removal and readout of the recording devices. Recorded data will be
      transferred to Kubios HRV® analysis software (version 2.2, Kuopio, Finland) for subsequent
      analysis. Calculated parameters comprise mean heart rate, square root of the mean squared
      differences of successive RR intervals (RMSSD), standard deviation of the normal-to-normal
      interval (SDNN) in the time domain, and and the number of pairs of succession
      normal-to-normal intervals that differ by more than 50ms divided by the total number of
      normal-to-normal intervals (pNN50); in the frequency domain low frequency (0.04-0.15 Hz, LF)
      and high frequency (0.16-0.40 Hz, HF) will be considered as proposed by international
      guidelines.
    

Intervention name(s): Gut-directed hypnotherapy
Intervention type(s): Behavioral
Intervention description(s): hypnotherapy
Intervention model: Single Group Assignment
Intervention model description: pre-post intervention
Masking: None (Open Label)
Primary purpose: Treatment