Significance of autonomic nervous system activity in functional dyspepsia.

The purpose of this study was to examine if patients with functional dyspepsia could be separated into meaningful groups based on their autonomic function. Subjects were divided into two groups, and symptoms, gastric myoelectrical activity, gastric emptying, and psychological factors were compared. Group 1 had less autonomic variability but more cardiac reactivity than group 2. Symptom reports did not differ between groups. Group 1 had higher neuroticism scores than group 2, while group 2 showed greater tachyarrhythmia in response to drinking water than group 1. The relatively low autonomic variability in group 1 is consistent with higher sympathetic activity and may be associated with the group's greater neuroticism. The relative lack of cardiac reactivity in group 2 is consistent with lack of autonomic flexibility and may be related to the tachyarrhythmia observed in that group. The results of this study suggest that autonomic function may play a significant role in functional dyspepsia.