Endocrine Abstracts

Irritable bowel syndrome (IBS) which is very common is characterized by chronic intermittent symptoms, including recurrent abdominal pain, altered frequency of defecation, stool urgency and excess flatus. Widespread symptoms associated with IBS are abnormal defecation and abdominal pain, both of which can be exacerbated by psychogenic stress. IBS is one of the stress-related bodily disorders and it has been suggested that patients with IBS may exhibit disturbances in the hypothalamo-pituitary-adrenal (HPA) axis. But there are only limited data regarding HPA axis in IBS.

In this study, we have assessed the HPA axis by 1 microgram ACTH stimulation test in 15 patients with IBS and in 15 age-sex-and body mass index (BMI) matched controls. ACTH stimulation test was carried out by using 1 microgram intravenous ACTH as a bolus injection after an overnight fast, and blood samples for cortisol were drawn at minus 15 0, 30, 60 minutes. Peak serum cortisol levels of 550 nanomoles per litre or greater were considered as a normal response for LDT.

Cortisol deficiency was detected in 1 (7.1 %) patient with IBS in LDT. Basal cortisol levels were similar between the groups. Peak cortisol level (726.0 plus/minus 242.0 nanomoles per litre) was not different in the patients with IBS than peak cortisol level (836.0 plus/minus 129.2 nanomoles per litre) in the control subjects (P>0.05).

This study shows that hypothalamo-pituitary-adrenal axis is normal in patients with IBS.