Effect of inhibition of gastric acid secretion on antropyloroduodenal motor activity and duodenal acid hypersensitivity in functional dyspepsia

Background: Heightened visceroperception and a decreased duodenal motor response to intraduodenal acid infusion have been reported in functional dyspepsia. Aim: To investigate the effect of treatment with a proton pump inhibitor on sensorimotor impairment in 19 patients with functional dyspepsia. Methods: Patients were assigned double-blind to pantoprazole (n = 10) or placebo (n = 9) treatment for 2 weeks. Antropyloroduodenal manometry was performed before and after treatment, using a 21-channel catheter, and the responses to intraduodenal infusion of 5 mL of saline and acid were assessed. Nausea, fullness and epigastric pain were scored before and after each infusion. Results: Acid induced a modest duodenal motor response and suppression of antral pressure waves, not altered by either treatment. However, acid evoked isolated pyloric pressure waves after pantoprazole treatment (P < 0.02), and not after placebo. Saline induced no motor response. Acid (not saline) induced nausea, both before and after treatment in both groups (all P < 0.05). Subgroup analysis of the seven acid-hypersensitive patients (37%) showed a tendency towards a decrease in nausea in all four pantoprazole-treated patients (P = 0.07), in contrast to the three placebo-treated patients (P = 1.0). Conclusions: In functional dyspepsia, pantoprazole influenced the acid-induced duodenogastric feedback mechanism, but not the impaired duodenal motor response. Duodenal acid hypersensitivity was decreased to some extent.