Hypersenstivity to Acid in Ulcer-Like Functional Dyspepsia

Abstract

ObjectivesThe mechanism of pain sensation in patients with ulcer-like functional dyspepsia is unclear and there are no guidelines for its treatment. Whilst much research and many pharmacological treatments have provided symptomatic relief of ulcer-like functional dyspepsia through control of acid secretion, the role of acid in ulcer-like functional dyspepsia is unknown. We carried out this study to investigate the role of hypersensitivity to acid in the sensation of pain in ulcer-like functional dyspepsia by direct administration of acid into stomach.MethodsTwelve patients with ulcer-like functional dyspepsia(5 male, 7 female, mean age 41.0 years old, 7 with mild chronic superficial gastritis, 2 with metaplastic gastritis and 3 with normal endoscopic findings) and seven healthy control subjects(3 male, 4 female, mean age 36.0 years old, 7 with normal endoscopic findings) participated in the study. After overnight fasting, a nasogastric sump tube was inserted and its tip was positioned in the antrum under fluoroscopic guidance. Normal saline or 0.1N hydrochloric acid was administrated in random and single blind cross over fashion. The test was considered positive only if similar pain developed-similar to that experienced by the patient under nonstudy condition- during the administration.ResultsFive patients(41.7%) developed pain with 0.1N hydrochloric acid administration, but none with normal saline(p<0.05). None of the healthy controls developed pain upon administration of 0.1N hydrochloric acid or normal saline.ConclusionWe suggest that acid hypersensitivity plays a role in the sensation of pain in ulcer-like functional dyspepsia.

Stomach-brain communication by vagal afferents in response to luminal acid backdiffusion, gastrin, and gastric acid secretion

“…Gastric exposure to 0 35. The number of c-Fos mRNA-positive cells visualized 45 min after intragastric treatment by ISH was roughly equivalent to that of c-Fos protein-positive cells, although after intragastric challenge with 0.35 M HCl, IHC seemed to reveal more activated cells than ISH(Fig.…”

“…This possibility was thought of because stimulation of gastric acid secretion by pentagastrin (2) or administration of exogenous acid (35) can give rise to pain in humans. This possibility was thought of because stimulation of gastric acid secretion by pentagastrin (2) or administration of exogenous acid (35) can give rise to pain in humans.…”

Asian Consensus Report on Functional Dyspepsia

“…Patients with postprandial pain are reported to have a high prevalence of pathological acid exposure, which suggests that patients who respond to acid-suppressive therapy might have non-erosive reflux disease 97. Several studies have suggested a role for increased duodenal acid exposure or duodenal or gastric hypersensitivity to acid in the pathogenesis of symptoms in some patients with FD 76,98-100. These factors might explain the beneficial effects of acid-suppressive treatment for FD.…”

Asian consensus report on functional dyspepsia

“…Patients with postprandial pain are reported to have a high prevalence of pathological acid exposure, which suggests that patients who respond to acid‐suppressive therapy might have non‐erosive reflux disease 97 . Several studies have suggested a role for increased duodenal acid exposure or duodenal or gastric hypersensitivity to acid in the pathogenesis of symptoms in some patients with FD 76,98–100 . These factors might explain the beneficial effects of acid‐suppressive treatment for FD.…”