An Assessment of Cognitive Function in Irritable Bowel Syndrome
Recruitment status was: Recruiting
Irritable bowel syndrome (IBS) is a common disorder affecting up to 20% of the general population. Despite the prevalence of the disorder, it remains poorly understood. This is reflected in a symptom based diagnostic scheme, the lack of a suitable biological marker and inadequate treatment options. Current knowledge suggests the disorder is as a result of a dysregulated brain-gut axis, a complex construct describing the bidirectional communication systems underpinning normal gastrointestinal functioning.
The investigators hypothesize here that the disruption of this brain-gut axis is facilitated by an increased degradation of tryptophan along the kynurenine pathway. This metabolic abnormality has the potential to impact on both GI and CNS signaling through its effects on serotonergic signaling and the impact of metabolites like kynurenic acid and quinolinic acid on cognitive processes respectively.
Previous data from our laboratory indicated increased tryptophan degradation in IBS patients and suggested the metabolites produced as putative biological markers of the condition. In this study the investigators aim to reconcile cognitive impairment in IBS with GI and CNS symptom severity and kynurenine pathway metabolites.
The investigators will establish these baseline measures in IBS compared to control subjects. A battery of cognitive assessments will be carried out using a computerized testing system. Standardized rating scales will be used to assess GI and CNS symptom severity. GC-MS/MS, a recently acquired technology platform in our laboratory, will be used to quantify plasma quinolinic acid levels.
Irritable Bowel Syndrome
|Study Design:||Observational Model: Case Control
Time Perspective: Cross-Sectional
|Official Title:||Kynurenine Pathway Metabolites as Novel Translational Biological Markers of Irritable Bowel Syndrome: Relationship to Gastrointestinal Function, Cognition and Co-morbid Depression|
- CANTAB Assessments [ Time Frame: Baseline ] [ Designated as safety issue: No ]Cognitive assessments using CANTAB, a computerised cognitive assessment package
- IBS Symptom Severity [ Time Frame: Baseline ] [ Designated as safety issue: No ]As assessment of IBS symptom severity using validated questionnaires
- Kynurenine Pathway Metabolies [ Time Frame: Baseline ] [ Designated as safety issue: No ]Plasma tryptophan, kynurenine, kynurenic acid, quinolinic acid
- Glucocorticoids [ Time Frame: Baseline ] [ Designated as safety issue: No ]Plasma/Salivary Cortisol
- Cytokines [ Time Frame: Baseline ] [ Designated as safety issue: No ]Plasma Cytokine concentrations
- Psychiatric Comorbidity [ Time Frame: Baseline ] [ Designated as safety issue: No ]Psychiatric comorbidity will be assessed according to DSM-IV criteria
- Sleep Quality [ Time Frame: Baseline ] [ Designated as safety issue: No ]The potential confounding effect of sleep quality will be established using the Pittsburg Sleep Quality Index
Biospecimen Retention: Samples With DNA
|Study Start Date:||January 2011|
|Estimated Study Completion Date:||January 2012|
|Estimated Primary Completion Date:||December 2011 (Final data collection date for primary outcome measure)|
Healthy Control Subjects
Subjects diagnosed with IBS
Show Detailed Description
Please refer to this study by its ClinicalTrials.gov identifier: NCT01304355
|Cork University Hospial|
|University College Cork|
|Principal Investigator:||Gerard Clarke, PhD||University College Cork|
|Principal Investigator:||Timothy G Dinan, Professor||University College Cork|
|Principal Investigator:||John F Cryan, PhD||University College Cork|