4 Is functional dyspepsia largely explained by gastro-oesophageal reflux disease?

Functional dyspepsia is a chronic disorder of unknown aetiology. The lack of endoscopic abnormalities in patients with this disorder has led many physicians to believe that gastrooesophageal reflux disease may be responsible for most symptoms. Our group has addressed this issue, by pathophysiological studies in a large cohort of Dundee patients with persistent dyspeptic symptoms. Peptic ulcer and gallstones were excluded in all patients by appropriate tests. Ambulatory pH monitoring showed oesophageal acid reflux that lay above the conventional diagnostic threshold in approximately 20% of patients. This subset was diagnosed as having gastro-oesophageal reflux disease.In the remainder, moderate or severe reflux-like symptoms were reported by approximately 44% patients, who were categorized as reflux-like functional dyspepsia. Reflux symptoms were mild or absent in 36% patients, who were categorized as non-reflux-like dyspepsia. While oesophageal pH profiles lay within the conventional normal range in both of these functional dyspepsia subgroups, patients with reflux-like functional dyspepsia had significantly greater acid exposure values, including total oesophageal acid exposure time, percentage time at a pH of less than 4.0, DeMeester scores and pain reflux event correlation. Hence patients with reflux-like functional dyspepsia have oesophageal acid exposure that lies below the diagnostic threshold for gastro-oesophageal reflux disease but exceeds that of patients with non-reflux dyspepsia. The high pain/reflux event correlation in reflux-like functional dyspepsia suggests that subthreshold oesophageal acid exposure may be associated with troublesome reflux symptoms.     

Correlation between oesophageal acid exposure and dyspeptic symptoms in patients with nonerosive reflux disease

BACKGROUND & AIMS: Oesophageal acidification induces dyspeptic symptoms in healthy individuals. This study aimed to evaluate the correlation between oesophageal acid exposure and dyspeptic symptoms in patients with nonerosive reflux disease. METHODS: A total of 68 patients with dominant symptoms of heartburn, negative upper gastrointestinal endoscopy and concomitant dyspeptic symptoms participated in the study. The severity of dyspepsia and reflux-related symptoms was evaluated, and 24-h gastro-oesophageal pH-monitoring study was performed in all patients at baseline and after 4 weeks of therapy with esomeprazole 40 mg. RESULTS: Oesophageal basal acid exposure was pathological in 43 patients and normal in 25 patients, with a similar prevalence and severity of individual dyspeptic symptoms in the two groups. A significant correlation between reflux and dyspepsia scores was observed in the subgroup of patients with normal, but not in those with abnormal pHmetry (r=0.4, P=0.04 and r=0.2 P=0.07, respectively). After esomeprazole, a reduction in severity of dyspepsia (>or=50% with respect to baseline) was observed, independent of improvement of reflux-associated symptoms. Improvement in dyspepsia was, however, similar in patients with normal and abnormal basal acid exposure (14/25 vs. 33/43, respectively, P=NS). CONCLUSION: Dyspeptic symptoms coexist in a subset of nonerosive reflux disease patients, but prevalence and severity of the symptoms seems to be independent of oesophageal acid exposure.     

Belching: dyspepsia or gastroesophageal reflux disease?

OBJECTIVES: Eructation (belching) is a common symptom seen in clinical practice. Because either belching or heartburn may result from transient lower esophageal sphincter relaxations, it has been proposed that belching may be a manifestation of gastroesophageal reflux disease (GERD). In this retrospective study we evaluated the prevalence of belching in dyspepsia and GERD and the relation of belching to acid reflux events documented by pH monitoring. METHODS: We examined the prevalence, frequency, and severity of belching and other GERD symptoms by use of standardized questionnaires in 180 GERD patients (group A) and 78 dyspeptic controls (group B) referred for evaluation at our institution. GERD was defined as either endoscopic esophagitis (or Barrett's esophagus) or positive DeMeester score (>14.2) on pH monitoring or both. Dyspeptic patients had normal endoscopy and pH studies. We also analyzed the relationship of belching to acid reflux events during the 24-h period of pH studies. RESULTS: Of 180 GERD patients, 132 (70%) reported belching during pH monitoring, versus 63 of 78 dyspeptic patients (80%) (p = ns). Similarly, 163 of 180 GERD patients (90%) reported heartburn versus 64 of 78 of dyspeptic patients (82%) (p = ns). Review of symptom questionnaires revealed no significant difference in belching severity between groups. However, heartburn and acid regurgitation were significantly more severe among GERD patients. There was a significantly higher correlation of both heartburn and belching with acid events in patients with GERD compared with patients with dyspepsia. In addition, although both belching and heartburn were significantly improved in patients with GERD, belching scores remained unchanged after proton pump inhibitor (PPI) therapy in patients with dyspepsia. CONCLUSIONS: Belching is as common and as severe in patients with dyspepsia as it is in patients with GERD. Belching and heartburn in GERD patients are more likely correlated with episodes of pathological acid reflux. Because belching cannot be clinically used as a discriminatory symptom, ambulatory pH monitoring should be considered to elucidate the relationship of belching to acid reflux in patients with dyspepsia or GERD.     

Symptomatic gastro-oesophageal reflux, abnormal oesophageal acid exposure, and mucosal acid sensitivity are three separate, though related, aspects of gastro-oesophageal reflux disease.

The Bernstein test has been used as a test of oesophageal acid sensitivity for over 30 years but its clinical value has been challenged by the advent of ambulatory pH monitoring. Furthermore, the relation between mucosal acid sensitivity, symptomatic reflux, and abnormal oesophageal acid exposure time is unclear. This study examined the relation between these three parameters in patients referred for pH monitoring with unexplained chest pain or heartburn. Fifty consecutive patients were studied - nine with non-cardiac chest pain and 41 with a history of heartburn. Symptomatic reflux was defined as a greater than or equal to 50% temporal association between pain episodes and reflux events (pH less than 4) during pH monitoring. A positive acid perfusion test (in which the patient's usual symptoms were evoked by acid, though not saline) had a 100% sensitivity, 73% specificity, and 81% accuracy for the detection of symptomatic reflux. All 10 patients with symptomatic reflux during pH monitoring had evidence of mucosal acid sensitivity. A negative acid perfusion test made symptomatic reflux unlikely. However, symptomatic reflux or a positive acid perfusion test, or both, were found in some patients with a normal oesophageal acid exposure time during pH monitoring. Mucosal acid sensitivity, abnormal oesophageal acid exposure time, and symptomatic reflux should be regarded as separate, though related aspects of reflux disease. The Bernstein test is simple, safe, and easily performed. A positive test helps to identify an oesophageal cause of symptoms, particularly in patients in whom other aspects of 'gastro-oesophageal reflux disease' are absent, or who do not have symptoms during pH monitoring.     

Importance of reflux symptoms in functional dyspepsia.

The relation between symptom severity in gastro-oesophageal reflux disease (GORD) and quantitated oesophageal acid reflux is variable. Furthermore, when oesophageal acid exposure lies within the conventional normal range, the cause of the symptoms is unknown. This prospective study evaluated 24 hour ambulatory oesophageal pH profiles in relation to objective symptom scores in 100 dyspeptic patients who were free from ulcer and gall stones. Twenty patients had raised oesophageal acid exposure and reflux symptoms consistent with GORD, and 80 had oesophageal pH profiles within the conventional normal range. Forty four of the 80 had severe or moderate reflux symptoms and were classified as having reflux like functional dyspepsia (RFD); 36 had minimal or absent reflux symptoms, and were categorised as having non-reflux dyspepsia (NFD). While oesophageal pH profiles lay within the conventional normal range in both functional dyspepsia subgroups, patients with RFD had consistently greater acid exposure values as follows: mean (SEM) total oesophageal acid exposure time, RFD 16.2 (2.56) min v NFD 9.05 (2.0) min (p < 0.03); percentage of time with pH < 4, RFD 1.4 (0.2) v NFD 0.8 (0.2) (p < 0.03); DeMeester scores, RFD 12.8 (0.5) v NFD 11.4 (0.4) (p < 0.03). The RFD group had a pain/reflux event correlation of 23.8 (5.3)% v 8.1 (3.7)% for the NFD group (p < 0.01). This study shows that patients with RFD have oesophageal acid exposure that lies below the diagnostic threshold for GORD, but exceeds that of patients with NFD. The high pain/reflux event correlation in RFD, suggests that subthreshold oesophageal acid exposure may be associated with troublesome reflux symptoms.     

Clinical presentation of Helicobacter pylori-positive and -negative functional dyspepsia

BACKGROUND: A questionnaire was used to record the clinical presentation of functional dyspepsia in relation to Helicobacter pylori infection in a consecutive series of patients sent for upper gastrointestinal endoscopy. Only patients without macroscopic abnormalities in their oesophagus, stomach and duodenum were included. METHODS: The study questionnaire included two questions related to daily life, and the calculation of a symptom score. Biopsy specimens were taken from all patients for histological and microbiological examination, and immunoglobulin G antibodies were also determined. RESULTS: Two hundred and twenty-two patients were H. pylori positive and 182 patients were H. pylori negative. Loss of weight was significantly more common in the H. pylori positive group (P<0.001). Patients with H. pylori infection had a significantly higher overall symptom score compared with H. pylori-negative subjects (P<0.05). In addition, the severity of epigastric and nocturnal pain, heartburn, retrosternal heartburn, and vomiting was significantly higher in H. pylori-positive functional dyspeptic patients, and the influence on daily life and activities was significantly worse. CONCLUSIONS: The combination of retrosternal pain, weight loss, food intolerance and the absence of halitosis signified a 64% accuracy in predicting H. pylori infection. It is not possible to differentiate between H. pylori-positive and H. pylori-negative functional dyspeptics on the basis of clinical presentation and the number of complaints. However, overall symptom score and severity of several symptoms was significantly higher in the H. pylori-positive group.     

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 28 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.     

Aktuelle Konzepte zur funktionellen Dyspepsie

The term “dyspepsia” describes chronic or intermittent complaints of the upper gastrointestinal tract that are characterized by epigastric pain, anorexia, fullness, belching, heartburn, nausea, and/or vomiting. In the general population, the prevalence of dyspeptic symptoms is about 15–20%. Most of these individuals suffer from functional dyspepsia (FD), with organic diseases such as peptic ulcer, esophagitis caused by gastroesophageal reflux, and neoplasia being much less common. The precise etiology of FD remains unknown. According to Rome III criteria, FD is defined as distinct epigastric complaints lacking a structural or biochemical explanation. Current hypotheses consider altered motility or visceral hypersensitivity as the underlying pathomechanism. Hence, the symptomatic pharmacological treatment mainly consists of compounds modulating motor activity and visceral nociception.     

EDITORIAL: Obesity influence on dyspeptic symptoms

"Background: There is a high prevalence of dyspepsia and obesity in Mexican population. A relationship between obesity and dyspeptic symptoms has been proposed. Objective: To determine prevalence of dyspeptic symptoms in patients with normal weight, overweight and obesity. Methods: Prospective study on consecutive patients who attend for medical assistance for any reason in a first level medical center. Weight, height, and body mass index (BMI) were measured. A validated questionnaire for dyspepsia was applied. Results: Three-hundred and twenty patients were included (61.6% women, n = 197). The mean patient age was 37 ± 14.4 years old. Mean BMI was 26.68 with 42.2% of patients (n = 135) overweight, 35.6% (n = 114) with normal weight and 22.2% (n = 71) were obese. Compared to patients with normal weight and overweight the obesity group showed a higher prevalence of gastritis symptoms, pain, stomachache, heartburn, a worst quality of life, and a higher frequency of medication intake. Patients with overweight presented a higher score in quality of life and treatment compared with normal weight patients. Conclusions: Obese patients showed a higher prevalence of dyspeptic symptoms compared to normal weight and overweight patients."     

Etiology of dyspepsia: implications for empirical therapy.

Dyspepsia describes a symptom complex thought to arise in the upper gastrointestinal tract and includes, in addition to epigastric pain or discomfort, symptoms such as heartburn, acid regurgitation, excessive burping or belching, a feeling of slow digestion, early satiety, nausea and bloating. Based on the evidence that heartburn cannot be reliably distinguished from other dyspeptic symptoms, the Rome definition appears to be too narrow and restrictive. It is particularly ill suited to the management of uninvestigated dyspepsia at the level of primary care. In patients presenting with uninvestigated dyspepsia, a symptom benefit is associated with a 'test and treat' approach for Helicobacter pylori infection. A substantial proportion of those who do not benefit prove to have esophagitis on endoscopy. In those with functional dyspepsia, the benefits of H pylori eradication, if any, appear to be modest. Hence, a 'symptom and treat' acid-suppression trial with proton pump inhibitors, and a 'test and treat' strategy for H pylori are two acceptable empirical therapies for patients with univestigated dyspepsia.     

Effect of domperidone therapy on nocturnal dyspeptic symptoms of functional dyspepsia patients

AIM:To investigate the incidence of nocturnal dyspeptic symptoms in patients with functional dyspepsia(FD) and whether prokinetic drugs can alleviate them. METHODS:Eighty-five consecutive Chinese patients with FD were included in this study.One week after single-blinded placebo run-in treatment,baseline nocturnal intragastric pH,bile reflux and nocturnal dyspeptic symptoms of eligible patients,including epigastric pain or discomfort,abdominal distention and belching, were investigated with questionnaires.Pa...     

Stratification and symptom characteristics of non-erosive reflux disease based on acid and duodenogastroesophageal reflux

Background and Aim: The subgroups and symptom characteristics of non‐erosive reflux disease (NERD) based on acid and duodenogastroesophageal reflux may be different in Chinese patients to Western patients. This study aimed to explore the stratification and symptom characteristics of patients with NERD. Methods: Patients with typical heartburn and/or acid regurgitation symptoms were enrolled. Each patient filled out a questionnaire. An upper gastrointestingal endoscopy was performed for each patient followed by simultaneous ambulatory 24‐h esophageal pH and Bilitec (bilirubin) monitoring. A symptom index (SI) of ≥50% was considered to be positive. Results: Eighty‐two consecutive NERD patients were evaluated. Abnormal (NERD pH+) and normal (NERD pH–) 24‐h pH tests were found in 24 (29.3%) and 58 (70.7%) patients, respectively. Among 42 NERD pH– patients who reported heartburn symptoms during monitoring, SI was positive in 19 (45.2%) patients (NE‐SI+) and negative in 23 (54.8%) patients (NE‐SI–). Pathological duodenogastroesophageal reflux (DGER) was found in 43 (52.4%) patients. No significant differences were noted regarding the prevalence of other upper gastrointestinal symptoms, except for acid regurgitation in NERD pH+ and NERD pH– groups. Additionally, no significant differences were seen in the prevalence of other symptoms, except for chest pain, in groups with pathological and normal DGER. Conclusion: The proportion of NERD patients with pathological acid reflux was somewhat lower than that reported in Western countries. The role of DGER in NERD may be important. It is difficult to differentiate whether NERD patients have pathological acid or bile reflux according to symptoms.     

Dyspepsia in England and Scotland

A validated postal questionnaire has been used to establish the prevalence of dyspeptic symptoms in five geographical locations from the south coast of England to the north of Scotland. The six month period prevalence of dyspepsia in the 7428 respondents to the questionnaire is 41% and equal between the sexes, with similar prevalence rates in the centres studied. There is considerable overlap between upper abdominal symptoms and symptoms of heartburn; 56% of patients with dyspepsia experience both groups of symptoms. Symptom frequency falls progressively with age in men and women, but the proportion of people seeking medical advice for dyspepsia rises with age. One quarter of the dyspeptic patients studied have consulted a general practitioner about their symptoms. This study suggests that the prevalence of dyspepsia in the community has changed little over the last 30 years, despite evidence that the frequency of peptic ulcer disease is falling. Symptom prevalence is unrelated to social class, but this factor is associated with consultation behaviour, the consultation rate rising from 17% in social class 1 to 29% in social class 4. The use of investigations--barium meal and endoscopy--is similarly related to social class; the lowest rate for ulcer diagnosis (4.7%) is found in social class 1 and the highest (17.1%) in social class 5.     

功能性消化不良患者胃排空与症状的相关性及影响因素分析

目的了解胃排空异常与消化不良症状的相关性,分析影响功能性消化不良（FD）患者胃排空的因素。方法纳入32例FD患者。量化记录餐后上腹饱胀、上腹痛、上腹烧灼感、早饱、嗳气、恶心、呕吐7组症状及静息心率。以心率的中位数将其转化为二分类变量进行非条件Logistic回归分析统计。运用核素闪烁法检测空腹固体试餐,试餐参考美国胃肠动力学会、神经胃肠学会及核医学联合推荐的标准低脂试餐以及诊断标准。结果 32例FD患者,8例（25%）T1/2延迟,7例（21.88%）Retention%2 h增加,Retention%1 h均在正常范围内。Retention%2 h正常组与Retention%2 h增加组以及T1/2正常组与T1/2延长组之间,心率均存在显著差异（P=0.031,P=0.022）,心率与Retention%2 h、T1/2存在正相关（r=0.448,P=0.01;r=0.423,P=0.016）。在控制了性别、年龄及其他症状因素的影响下,心率〉70 bpm是Retention%2 h增加、T1/2延长的独立因素（OR=12.378,P=0.042;OR=8.180,P=0.072）。在Retention%2 h正常组与Retention%2 h增加组之间恶心症状指数有显著差异（P=0.003）,恶心与Retention%2 h、T1/2存在正相关（r=0.527,P=0.002;r=0.381,P=0.032）。结论心率、恶心症状与功能性消化不良患者的胃排空存在一定相关性,在控制了性别、年龄、BMI及其他症状的因素影响下,静息心率增加、出现恶心症状可能是胃排空延缓的独立因素。     

Diagnosis and management of patients with reflux symptoms refractory to proton pump inhibitors

Approximately a third of patients with suspected gastro-oesophageal reflux disease are resistant or partial responders to proton pump inhibitors (PPIs). Many of these patients do not have gastro-oesophageal reflux disease, but suffer from functional heartburn or dyspepsia. The potential mechanisms underlying failure of PPI treatment in patients with reflux-related symptoms include persistence of isolated or mixed acid, weakly acidic, bile or gas reflux, impaired oesophageal mucosal integrity, chemical or mechanical hypersensitivity to refluxates and psychological comorbidity. After thorough clinical evaluation and failure of empirical changes in PPI dose regime, diagnostic investigations include endoscopy and reflux monitoring with pH or pH-impedance monitoring. If symptoms are clearly related to persistent reflux, baclofen, antireflux surgery or pain modulators can be considered. If not, pain modulators are the only currently available therapy.     

Dyspepsia and Helicobacter pylori infection: a prospective multicentre observational study

OBJECTIVES: Dyspepsia still represents an unsolved clinical enigma. AIM: The aims of this study were to determine whether symptoms and Helicobacter pylori infection are predictors of organic disease in uninvestigated dyspepsia, and if H. pylori eradication improves symptoms in functional dyspepsia. METHODS: An observational study was performed on outpatients with uninvestigated dyspepsia. Symptoms were scored and H. pylori status determined. Patients with functional dyspepsia and H. pylori infection were randomly given either a standard eradicating treatment or a 1-month course of empirical treatment. The latter was also given to functional dyspeptic patients without infection. Symptoms were re-assessed in functional dyspeptic patients at 2- and 6-month follow-up visits. Patients receiving eradicating treatment were re-tested for H. pylori at the 2 month visit. RESULTS: A total of 860 patients were studied and 605 (70.3%) were affected by functional dyspepsia. H. pylori infection was diagnosed in 71.8% of patients with organic dyspepsia and in 65.0% with functional dyspepsia (p=0.053). Male sex, anaemia, smoking habit, age over 45 years, and severe epigastric pain, but not H. pylori infection, were independent predictors of organic disease. Symptoms significantly improved in most functional dyspeptic patients regardless of their H. pylori status and type of treatment. CONCLUSION: H. pylori infection is not a strong predictor of organic disease in uninvestigated dyspepsia. H. pylori eradication is not essential to improve symptoms in functional dyspepsia.     

Reflux related symptoms in patients with normal oesophageal exposure to acid.

Several studies, using pH monitoring with event markers, have identified patients with normal oesophageal exposure to acid despite an apparent relation between symptoms and reflux episodes. In this series of 771 consecutive patients referred for 24 hour oesophageal pH monitoring, a probability calculation was used to evaluate the relation between symptoms and reflux episodes. Oesophageal exposure to acid was normal in 462 of 771 recordings (59.9%); despite this, 70.8% (327 of 462) of these patients used at least once the event marker. In 96 patients (12.5% of total patients) with normal oesophageal exposure to acid, there was a statistically significant association between symptoms and reflux episodes. The symptom cluster of such patients was similar to that usually seen in patients with gastro-oesophageal reflux disease, but symptoms like belching, bloating, and nausea were common thus overlapping with the symptom pattern of functional dyspepsia. In these patients both the duration and the minimum pH of reflux episodes (either symptom related or asymptomatic) were significantly shorter and higher, respectively, when compared with those of patients with gastro-oesophageal reflux disease. These results are consistent with the idea that oesophageal hypersensitivity to acid is the underlying pathophysiological feature of this syndrome.     

Plasma levels of acylated ghrelin in patients with functional dyspepsia

AIM: To investigate the relationship between plasma acylated ghrelin levels and the pathophysiology of functional dyspepsia.METHODS: Twenty-two female patients with functional dyspepsia and twelve healthy volunteers were recruited for the study. The functional dyspepsia patients were each diagnosed based on the Rome III criteria. Eligible patients completed a questionnaire concerning the severity of 10 symptoms. Plasma acylated ghrelin levels before and after a meal were determined in the study participants using a commercial human acylated enzyme immunoassay kit; electrogastrograms were performed for 50 min before and after a standardized 10-min meal containing 265 kcal.RESULTS: There were no significant differences in plasma acylated ghrelin levels between healthy volunteers and patients with functional dyspepsia. However, in patients with functional dyspepsia, there was a negative correlation between fasting plasma acylated ghrelin levels and the sum score of epigastric pain (r = -0.427, P = 0.047) and a positive correlation between the postprandial/fasting plasma acylated ghrelin ratio and the sum score of early satiety (r = 0.428, P =0.047). Additionally, there was a negative correlation between fasting acylated ghrelin plasma levels and fasting normogastria (%) (r = -0.522, P = 0.013). Interestingly, two functional dyspepsia patients showed paradoxically elevated plasma acylated ghrelin levels after the meal.CONCLUSION: Abnormal plasma acylated ghrelin levels before or after a meal may be related to several of the dyspeptic symptoms seen in patients with functional dyspepsia.     

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-HT(3) 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-HT(3) 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.     

Dyspeptic symptoms associated with hypersensitivity to gastric distension induced by duodenal acidification

BACKGROUND AND AIM: Duodenal acidification might increase sensitivity to gastric distension, which seems to play a role in the genesis of dyspeptic symptoms in a subset of patients with functional dyspepsia. The aim of the present study was to investigate the characteristics of dyspeptic symptoms associated with hypersensitivity to gastric distension induced by duodenal acidification. METHODS: An infusion tube and a barostat bag were positioned in the duodenum and gastric fundus, respectively. Sensitivity to stepwise fundic distensions with severity scoring of the seven dyspeptic symptoms was assessed before and during duodenal acid infusion in 20 healthy subjects. RESULTS: Acid infusion significantly decreased the pressures and the corresponding wall tensions at the thresholds for discomfort. At the distending level of minimal distending pressure (MDP) + 2 mmHg, significantly higher scores of fullness and bloating were obtained during acid infusion. With distending stimuli of MDP + 4 and 6 mmHg, fullness, bloating, nausea, satiety, epigastric burning and epigastric pain were significantly more severe during acid infusion than before acid infusion. At the level of MDP + 8 mmHg, the severity of epigastric pain was significantly greater, compared with that before acid infusion. CONCLUSIONS: Duodenal acidification might aggravate dyspeptic symptoms through the induction of hypersensitivity to gastric distension in healthy individuals. Those symptoms are diverse and variable, depending on the strength of the distending stimuli.