Background and objectives: Patients with functional dyspepsia exhibit increased sensitivity to gastric distension (mechanoreceptors) and to meals rich in fat (chemoreceptors). The aim of this study was to test whether these patients were abnormally sensitive to intraduodenal lipid, and whether this stimulus altered gastric mechanosensitivity.
Methods and design: Experiments were conducted on 10 patients and 10 healthy controls. The stomach was distended with a flaccid bag during duodenal infusion of either 10% Intralipid or 0.9% saline. Intragastric pressure was recorded continuously, and the participants were asked to report gastric sensations of fullness and discomfort.
Results: Intragastric pressure profiles during distension were similar in patients and controls. Lipid decreased intragastric pressure and reduced phasic contractility. Patients showed enhanced sensitivity to gastric distension compared with controls during both saline and lipid infusions. In the controls, threshold volumes for fullness and discomfort were higher during lipid than saline infusion. In the patients, the sensation of fullness occurred at lower volumes during lipid infusion, whereas discomfort occurred at similar volumes but lower intragastric pressures. Most patients experienced nausea and bloating and three patients vomited during lipid infusion, but remained asymptomatic during saline infusion. Controls reported no symptoms during either infusion.
Conclusion: Dyspeptic patients have increased sensitivity to both gastric distension and intraduodenal lipid. In contrast to controls, lipid sensitizes their stomachs to distension.