Role of autonomic dysfunction in patients with functional dyspepsia

Background. The role of autonomic dysfunction in patients with functional dyspepsia is not completely understood. Aims. 1. to prospectively assess abnormalities of autonomic function in patients with functional dyspepsia, 2. to assess whether autonomic dysfunction in these patients is associated with a. visceral hypersensitivity or b. delayed gastric emptying or c. severity of dyspeptic symptoms. Patients. A series of 2B patients with functional dyspepsia and 14 healthy volunteers without gastrointestinal symptoms were studied. Methods. All patients and controls were submitted to a battery of five standard cardiovascular autonomic reflex tests, dyspeptic questionnaire, gastric barostat tests and gastric emptying tests. Results. 1. Autonomic function tests showed that both sympathetic and parasympathetic scores of dyspeptic patients were significantly higher than in controls; 2. visceral hypersensitivity was confirmed in dyspeptics in response to proximal gastric distension, demonstrating lower pain threshold; 3. delayed gastric emptying occurred more frequently in patients with functional dyspepsia than in controls; 4. epigastric pain and epigastric burning were significantly more prevalent in patients with definite evidence of autonomic dysfunction; 5. No significant association was found between presence of autonomic dysfunction and presence of visceral hypersensitivity or presence of delayed gastric emptying in patients with functional dyspepsia. Conclusions. We concluded that a possible role of autonomic dysfunction in eliciting dyspeptic symptoms could not be determined from alterations in visceral hypersensitivity or delayed gastric emptying. Autonomic dysfunction might not be the major explanation for symptoms associated with functional dyspepsia.