Kwang-Jae Lee

Prevalence of acid reflux in functional dyspepsia and its association with symptom profile

Aim: A subset of functional dyspepsia patients respond to acid suppressive therapy, but the prevalence of non-erosive reflux disease in functional dyspepsia and its relevance to symptoms have never been established. The aim of the present study was to study 24 hour pH monitoring in consecutive functional dyspepsia patients. Methods: A total of 247 patients with dyspeptic symptoms (166 women, mean age 44 (SEM 1) year), with a negative upper gastrointestinal endoscopy and without dominant symptoms of heartburn participated in the study. In all patients, the severity of dyspeptic symptoms and the presence of heartburn was assessed by a questionnaire and a 24 hour oesophageal pH monitoring study was performed. All patients underwent a gastric emptying breath test and in 113 a gastric barostat study was performed. Results: Abnormal pH monitoring (acid exposure >5% of time) was found in 58 patients (23%). Of 21 patients with a positive heartburn questionnaire, 76% had pathological pH monitoring, while this was the case in only 18.5% of patients with a negative heartburn questionnaire. Demographic characteristics and the prevalence of other pathophysiological mechanisms did not differ between heartburn negative patients with normal or abnormal acid exposure. Pathological acid exposure in heartburn negative patients was associated with the presence of epigastric pain (65 v 84%, p<0.005) and of moderate or severe pain (48 v 69%, p = 0.005). Conclusion: Pathological oesophageal acid exposure is only present in a subset of heartburn negative functional dyspepsia patients, which are characterised by a higher prevalence of epigastric pain.

A Pilot Study on Duodenal Acid Exposure and Its Relationship to Symptoms in Functional Dyspepsia with Prominent Nausea

BACKGROUND:Duodenal hypersensitivity to acid and decreased duodenal clearance of exogenous acid have been reported in functional dyspepsia (FD). However, the relevance of these abnormalities to spontaneous duodenal acid exposure and dyspeptic symptoms in FD is unknown.AIMS:To determine spontaneous duodenal acid exposure and its relationship with symptoms, duodenal sensitivity to acid, and the effects of a 5-HT3 receptor antagonist on duodenal responses to acid in FD.METHODS:Eleven FD patients with prominent nausea and 11 healthy controls underwent 24-h ambulatory duodenal pH monitoring with assessment of dyspeptic symptoms. On the next day, duodenal bolus infusions of 5 ml of acid and normal saline were given in a randomized double-blind manner and repeated after ondansetron or a placebo.RESULTS:Nighttime duodenal acid exposure was similar, but FD patients had lower duodenal pH and higher duodenal % time (pH < 4) than controls during the daytime and in the second postprandial 2 h (p < 0.05). Seven patients (64%) with duodenal acid exposure above the normal range had higher severity scores for several dyspeptic symptoms including nausea. However, the symptom severity was poorly or weakly correlated to duodenal pH, and brief duodenal acid infusion did not affect any symptoms. Duodenal responses to exogenous acid were unaffected by 5-HT3 receptor antagonism.CONCLUSIONS:Spontaneous duodenal acid exposure is increased in a subset of FD patients with prominent nausea, and this is associated with more severe dyspeptic symptoms. However, a direct relationship between duodenal acid exposure and symptom severity is lacking.

Regional differences of the stomach in the motor and sensory response to gastric distension and the role of simultaneous distending stimuli

Background: [inputted gastric accommodation, wltb redistribution of the meal to the distal stomach, }*as been imphcated m the pathogenesis of functional dyspepsia symptoms. However, it rentains unclear Which part of the stomach is responsible for symptom generation. Recent studies suggest differential sensitivities of each region, but simukaneons barostat studies have not been pertbrmed The aim of the present study was to investigate the effect at separate and simukaneous bamstat distention of proximal and distal stomach in man. Methods: In 11 beahby volunteers (10 males: age 29• 1 years), a long tube assembly was placed through the py!orus Two bamstat balloons were attached to the tube at distances ensuring location irt the proximal and distal stomach Stepwise isobanc distentiorts of either bag were perfonned in a randomized order. VAt scores at each distending step assessed intensity of discomior~, balhress, bloating, nausea, belching, epigastric burning and satiety Distentions were pe~tormed with or without background distentim~ of the other bag at MDP + 2mmHg Finally, accommodation of the proxin*al stomach was assessed alter ingestion of a liquid meal w*th background antraI distention. Resnhs: The distal stomach had s*gnificandy lower compliance (56 • 4 vs 93 • 6 mUmmHg; p<0.001) Pressures and corresponding volumes at perception threshold d*d not differ between proximal and distal stomach (4 • 1 vs, 5 • 1 mmHg, 213 • (54vs. 219 • 66 mL; NS). At diseomtort threshold, pressures were not slgnflcantly different (12 • 2vs. 14 • 2mmHg, NS) but corresponding distal stomach volumes were slgndtcantly lower (959_+. 89 vs. 651 • 71 nil.; p<0.001) Perception scores and severity of individuaI symptoms at tim same distending pressures did not differ between the proximal and distal stomach. Backgeound distention did not significantly affect the pressures and the corresponding volumes at the thresholds tar perception and tbr discomfort, Conclusions: The sensi i*`aty to distension and the symptoms reduced bydistensmns do not differ between the proximal and distal stomach in man A low level of simultaneous distension does not modiI} 9 the percepuon of gastric distension.

Effects of sildenafil on duodenal motor response to acid, duodenal sensitivity to acid and the perception of duodenal distension in healthy subjects

Background: Duodenal hypersensitivity to acid and increased duodenal acid exposure due to decreased duodenal clearance of acid were recently reported in a subset of functional dyspepsia patients. However, the underlying mechanism remains unclear. Ainmal studies suggest involvement of nitric oxide in duodenal motor activity and nociception/antinociception. Our aim was to investigate the effects of the phosphodiesterase inhibitor sildenaftl on duodenal motor response to acid, sensitiwty to acid, and the perception of duodenal distension. Methods: In 8 healthy stibjects (4 males, 29+-2 years), a combined antroduodenal manometry and duodenal barostat catheter was imroduced through the mouth. The assembly, including a pH electrode and an infusion tube, was positioned in the 2nd duodenum. Stepwise isobaric distensions with symptom assessment were perbrmed, subsequently, duodenal motility, pH and symptom severity were assessed with administration of sildenafll 50 mg or saline intraduodenalfy in a randomized, double-blind manner. Fifteen min later, duodenal responses to 0.1 N HC1 infusion and to isobaric distentions were assessed. Results: Sildenafil, but not placebo, sigmficantfy decreased motility index (MI) proximal to the infusion site (4.1 +-0.4 vs. 1.3+-0.6 mmHg*sec; p<O.05). After placebo, acid infusion significantly increased the MI in the proximal channel within 5 minutes (4.0--.0.5 vs. 5.6+-0.4 mmHg*sec; p<0.05). After sildenafil, a similar increase in MI occurred (4.1 +-0.4 vs. 5.6+-0.3 mmHg*sec; p<0.05). Placebo had no significant influence on pressures at discomfort threshold (13+_2 vs. 13+-2 mmHg above MDP; NS). Similarly, no significant differences in pressures at discomfort threshold were observed (15-+ 2 vs. 14-+ 2 mmHg above MDP; NS). At the same distending pressures, perception scores after sildenafil and placebo were not different. Conclusions: Although sildenafil inhibits duodenal motility, it does not alter duodenal motor response to acid, sensitivity to duodenal acid infusion or senainvity to duodenal distension. These data show no major role for nitric oxide in the control of duodenal sensorimotor function in man.