Effect of mental stress and cisapride on autonomic nerve functions in functional dyspepsia

Disordered autonomic nerve function is frequently present in patients with functional dyspepsia (FD). In this study we investigated whether the prokinetic cisapride, which acts via acetylcholine receptors, and stress may modulate these abnormalities.

Nineteen patients (6 men, 13 women) with FD and 10 healthy subjects (3 men, 7 women) were studied after 3 days' treatment with 10 mg cisapride three times daily and placebo in a crossover design. Mental stress was induced with a videogame. Sympathetic and vagal nerve functions were assessed noninvasively by skin conductance and respiratory sinus arrhythmia, respectively.

Vagal tone was significantly lower in FD patients than in controls both before and after mental stress (P < 0.001). Sympathetic tone was higher in patients with FD than in controls (P < 0.03). Generally, stress scores were increased by mental stress in both groups (P < 0.001). In FD patients, but not in controls, cisapride significantly increased the sympathetic tone both before (P < 0.05) and after stress (P < 0.05).

Patients with FD have lower vagal tone and higher sympathetic tone than healthy controls. Treatment with cisapride increased sympathetic tone in the patient group but had no effect on vagal tone.