ABSTRACT
Objective: To evaluate sympathetic adrenergic function in irritable bowel syndrome (IBS) patients. Methods: Standard cardiovascular reflex tests were performed on forty patients with IBS and thirty healthy subjects. Sympathetic adrenergic function was assessed by measuring diastolic blood pressure response to hand grip test (HGT) at 4 min and cold pressor test (CPT) at 1min and also blood pressure response to head-up-tilt (HUT). Results: The change in diastolic pressure during (HGT) and (CPT) of IBS patients were not significantly different when compared to control. However, tilting resulted in less marked rise in diastolic pressure (6.14 ± 0.69 vs 12.1 ± 1.24 mmHg; p < 0.05) at 0.5 min and less rise in heart rate (6.03 ± 1.26 vs 10.35 ± 1.04 per min; p < 0.05) at 1 min in IBS patients. Conclusion: IBS patients had reduced sympathetic drive to (HUT) stress; however, subgroups of IBS had similar autonomic reaction.