The brain-gut axis has been proposed to influence symptoms in irritable bowel syndrome.
In animal studies, corticotropin-releasing hormone challenge has been associated with decreased upper gastrointestinal (GI) motility and increased colonic motility.
|Individuals with low post-dexamethasone cortisol level had early satiety|
|Scandinavian Journal of Gastroenteology|
Dr Pontus Karling and colleagues from Sweden investigated the association between gastrointestinal symptoms and the effect of corticotropin-releasing hormone on the hypothalamic-pituitary-adrenal axis.
The research team evaluated a weight-adjusted low-dose dexamethasone test in 157 healthy individuals.
The team analyzed pre- and post-dexamethasone morning serum cortisol.
All participants completed questionnaires regarding symptoms of irritable bowel syndrome (Gastrointestinal Symptom Rating Scale-IBS score).
The participants also answered questions on symptoms of anxiety and depression Hospital Anxiety and Depression Scale.
After exclusions, 124 subjects were available for analysis with a mean age of 56 years.
The researchers found a positive correlation between the Gastrointestinal Symptom Rating Scale-IBS score and Hospital Anxiety and Depression Scale score.
The team found no linear correlation between either pre- or post-dexamethasone cortisol levels and Gastrointestinal Symptom Rating Scale-IBS scores.
By subgrouping the subjects at the lower and higher 25th percentiles of their post-dexamethasone morning cortisol levels, the team found a trend towards a higher Gastrointestinal Symptom Rating Scale-IBS score.
The team noted a significantly higher diarrhea score, and a higher early satiety score in the subjects with high post-dexamethasone cortisol levels.
Furthermore, individuals with low post-dexamethasone cortisol levels (or a high hypothalamic-pituitary-adrenal suppression) showed a higher score for diarrhea.
Individuals with low post-dexamethasone cortisol level also had early satiety compared with those with intermediate cortisol levels.
Dr Karling's team concluded, "A trend toward a non-linear relationship between irritable bowel syndrome-like symptoms and post-dexamethasone cortisol levels was observed in healthy individuals."
"With significantly more symptoms of diarrhea and early satiety in individuals with high or low post-dexamethasone cortisol levels in comparison with those with intermediate post-dexamethasone cortisol levels."