Pathogenesis of gastro-oesophageal reflux disease and novel options for its therapy

Identification of Sliding Hiatus Hernia by High-Resolution Manometry and Upper Gastrointestinal Endoscopy in Patients with Gastro-Oesophageal Reflux Disease

BACKGROUND/AIM

The aim of this study was to compare high-resolution manometry (HRM) and upper gastrointestinal (GI) endoscopy as diagnostic utilities in detecting a sliding hiatus hernia in patients with gastro-oesophageal reflux disease (GORD) symptoms.

MATERIAL AND METHODS

For both diagnostic modalities, the data obtained from 31 patients (20 females; mean age 48.2) who qualified for Nissen fundoplication were analysed using oesophageal pressure topography in line with the Chicago Classification. Confirmation of hiatus hernia during the surgery was considered the gold standard. HRM protocol involved 10 consecutive boluses of 10 mL of water.

RESULTS

Sliding hiatus hernia was confirmed intraoperatively in 29 out of 31 patients. In 14 patients, hiatus hernia was detected in HRM, while 19 patients were found to have hiatus hernia by upper GI endoscopy before surgery. No false positive results were obtained in HRM, while 15 false negative results were shown. In upper GI endoscopy, false positive data were observed in 1 patient, while false negative results were found in 10 patients. Thus, the sensitivity of HRM in detecting hiatus hernia was 48% (95%CIs: 29-67%), and sensitivity of upper GI endoscopy was 66% (95%CIs: 46-82%). It was not possible to assess the specificity of HRM or upper GI endoscopy because only 2 of 31 patients had no hiatus hernia during fundoplication (gold standard). False negative results (sensitivity) were not significantly different between compared diagnostic modalities HRM and upper GI endoscopy (52% vs. 34%, respectively, p = 0.29).

CONCLUSIONS

Due to poor sensitivity, both modalities, i.e., HRM and upper GI endoscopy, are not reliable tools to diagnose sliding hiatus hernia in patients with GORD symptoms.

Understanding the relationship between esophageal motor disorders and reflux disease

INTRODUCTION

The management of gastro-esophageal reflux disease (GERD) patients is often complex as the clinical presentation is heterogeneous and the mechanisms underlying symptoms are multifactorial. In the past decades, investigations conducted with conventional manometry and, above all, the more accurate high resolution manometry (HRM), helped us in exploring the field of esophageal motility and in understanding the link between motor features and GERD pathogenesis.

AREAS COVERED

Several studies carried out with conventional manometry and HRM have confirmed a relevant role of esophageal motor function in GERD pathogenesis. In particular, HRM studies have shown a direct correlation between impaired esophageal body motility, disruption of the esophagogastric junction and reflux burden. These findings impact the clinical and therapeutical management of GERD patients. Moreover, HRM findings might be helpful in evaluating patients with proton pump inhibitor (PPI) resistance and inconclusive evidences of GERD.

EXPERT OPINION

The relationship between esophageal motility and GERD pathogenesis needs to be further evaluated by multicenter outcome studies involving a large number of GERD patients and healthy controls. However, other more promising areas could be progressed.

Recommendations of the Russian Gastroenterological Association on Clinical Use of High-Resolution Manometry in Diagnosis of Esophageal Disorders

Aim. Current recommendations of the Russian Gastroenterological Association on clinical use of high-resolution manometry in diagnosis of esophageal disorders are intended to assist in clinical decision making, terminology standardisation and interpretation of clinical data.

Key points. In 2018, a joint meeting of the Russian Gastroenterological Association and Russian Neurogastroenterology and Motility Group approved unified terminology and classification of esophageal motor function disorders for high-resolution manometry diagnosis.

Gastrointestinal patient complaints typically concern esophageal disorders such as dysphagia, regurgitation, heart-burn, chest pain or belching. To exclude erosive and ulcerative lesions, eosinophilic esophagitis and organic changes, esophagogastroduodenoscopy and biopsy are recommended in pre-treatment. Upon excluding mucosal lesions and esophageal lumen obstruction as causal for symptoms, use of high-resolution manometry is recommended. This method of esophageal examination has become the “gold standard” in diagnosis of motor disorders.

High-resolution manometry enables detailed investigation of integral quantitative and qualitative characteristics of esophagus motor function and specific related disorders, analysis of esophageal contractile propagation and strictly coordinated synchronous peristalsis of upper esophageal sphincter, esophagus and lower esophageal sphincter, which malfunction may provoke development of achalasia, esophagospasm, hiatal hernia, ineffective eso pha geal motility and other motor disorders.

Conclusion. High-resolution manometry is a relatively new method for study of esophagus motor function gaining increasingly wide application in clinical practice. It enables a medical professional to obtain evidence that may critically affect the choice of optimal patient care strategy and effective treatment. Current recommendations are based on an extensive review of up-to-date information and will be updated with new corpus of clinical data and assessment emerging in evidential medicine to provide gastroenterologists country-wide with latest scientific and practical guidelines.

Association between Increased Gastric Juice Acidity and Sliding Hiatal Hernia Development in Humans

Objectives

Several clinical factors; overweight, male gender and increasing age, have been implicated as the etiology of hiatal hernia. Esophageal shortening due to acid perfusion in the lower esophagus has been suggested as the etiological mechanism. However, little is known about the correlation between gastric acidity and sliding hiatus hernia formation. This study examined whether increased gastric acid secretion is associated with an endoscopic diagnosis of hiatal hernia.

Methods

A total of 286 consecutive asymptomatic patients (64 were diagnosed as having a hiatal hernia) who underwent upper gastrointestinal endoscopy were studied. Clinical findings including fasting gastric juice pH as an indicator of acid secretion, age, sex, body mass index, and Helicobacter pylori infection status determined by both Helicobacter pylori serology and pepsinogen status, were evaluated to identify predictors in subjects with hiatal hernia.

Results

Male gender, obesity with a body mass index >25, and fasting gastric juice pH were significantly different between subjects with and without hiatal hernia. The cut-off point of fasting gastric juice pH determined by receiver operating curve analysis was 2.1. Multivariate regression analyses using these variables, and age, which is known to be associated with hiatal hernia, revealed that increased gastric acid secretion with fasting gastric juice pH <2.1 (OR = 2.60, 95% CI: 1.38–4.90) was independently associated with hiatal hernia. Moreover, previously reported risk factors including male gender (OR = 2.32, 95% CI: 1.23–4.35), body mass index >25 (OR = 3.49, 95% CI: 1.77–6.91) and age >65 years (OR = 1.86, 95% CI: 1.00–3.45), were also significantly associated with hiatal hernia.

Conclusions

This study suggests that increased gastric acid secretion independently induces the development of hiatal hernia in humans. These results are in accordance with the previously reported hypothesis that high gastric acid itself induces hiatal hernia development.

Positive predictors for gastroesophageal reflux disease and the therapeutic response to proton-pump inhibitors

AIM: To identify objective and subjective predictors for the reliable diagnosis of gastroesophageal reflux disease (GERD) and the response to proton pump inhibitor (PPI) therapy.

METHODS: Retrospectively, 683 consecutive patients suspected for GERD who underwent pH-metry/impedance measurement (pH/MII) were analyzed. All patients had previously undergone standard PPI treatment (e.g., pantoprazole 40 mg/d or comparable). Four hundred sixty patients were at least 10 d off PPIs (group A), whereas 223 patients were analyzed during their ongoing PPI therapy (group B). In addition, all patients completed a standardized symptom- and lifestyle-based questionnaire, including the therapeutic response to previous PPI trials on a 10-point scale. Uni- and multivariance analyses were performed to identify criteria associated with positive therapeutic response to PPIs.

RESULTS: In group A, positive predictors (PPs) for response in empirical PPI trials were typical GERD symptoms (heartburn and regurgitation), a positive symptom index (SI) and pathological results in pH/MII, along with atypical symptoms, including hoarseness and fullness. In group B, regular alcohol consumption was associated with the therapeutic response. The PPs for pathological results in pH/MII in group A included positive SI, male gender, obesity, heartburn and regurgitation. In group B, the PPs were positive SI and vomiting. Analyzing for positive SI, the PPs were pathological pH and/or MII, heartburn regurgitation, fullness, nausea and vomiting in group A and pathological pH and/or MII in group B.

CONCLUSION: Anamnestic parameters (gender, obesity, alcohol) can predict PPI responses. In non-obese, female patients with non-typical reflux symptoms, pH/MII should be considered instead of empirical PPIs.

Impedance-high resolution manometry analysis of patients with nonerosive reflux disease

BACKGROUND & AIMS

Transient lower esophageal sphincter relaxations (TLESRs) contribute to episodes of reflux. Few studies have assessed the frequencies or compositions of TLESRs and reflux episodes in patients with reflux disease. We used combined high-resolution manometry and impedance monitoring to analyze reflux episodes and esophageal motility in these patients, compared with those of healthy individuals.

METHODS

We evaluated the frequency of TLESRs and the relationship between the reflux pattern and esophageal pressures during TLESRs in 14 patients with nonerosive reflux disease (NERD) and 11 controls. Study participants underwent combined high-resolution manometry and impedance monitoring before and 60 minutes after a solid and liquid meal. The diagnosis of NERD was confirmed by a 24-hour pH impedance test.

RESULTS

The frequency of TLESRs did not differ between patients with NERD and controls. In patients with NERD, TLESRs were associated more often with reflux episodes than in controls (93% ± 6% vs 66% ± 19%; P < .05). Patients with NERD had a higher percentage of pure liquid reflux episodes (33% ± 15% vs 10% ± 2%; P < .05), whereas controls had a higher percentage of mixed reflux episodes (45% ± 16% vs 67% ± 17% in patients with NERD; P < .05). Patients with NERD also had a higher percentage of reflux (liquid and mixed) associated with common cavities (74% ± 18% vs 50% ± 20% in controls; P < .05).

CONCLUSIONS

In contrast to previous studies, we found that TLESRs are associated more often with reflux in patients with NERD than control subjects; this association increases when only liquid and mixed refluxes are considered. These findings indicate that factors involved in the occurrence of reflux in patients with NERD during TLESRs are different from those in healthy subjects.

Evaluation of gastroesophageal function and mechanisms underlying gastroesophageal reflux in infants and adults born with esophageal atresia

PURPOSE

To evaluate the mechanisms underlying gastroesophageal reflux (GER) following esophageal atresia (EA) repair and gastroesophageal function in infants and adults born with EA.

METHODS

Ten consecutive infants born with EA as well as 10 randomly selected adult EA patients were studied during their first postoperative follow-up visit and a purposely planned visit, respectively. A (13)C-octanoate breath test and esophageal pH-impedance-manometry study were performed. Mechanisms underlying GER and esophageal function were evaluated.

RESULTS

Transient lower esophageal sphincter relaxation (TLESR) was the most common mechanism underlying GER in infants and adults (66% and 62%, respectively). In 66% of all GER episodes, no clearing mechanism was initiated. On EFT, normal motility patterns were seen in six patients (four infants, two adults). One of these adults had normal motility overall (>80% of swallows). Most swallows (78.8%) were accompanied by abnormal motility patterns. Despite this observation, impedance showed normal bolus transit in 40.9% of swallows. Gastric emptying was delayed in 57.1% of infants and 22.2% of adults.

CONCLUSIONS

TLESR is the main mechanism underlying GER events in patients with EA. Most infants and adults have impaired motility, delayed bolus clearance, and delayed gastric emptying. However, normal motility patterns were seen in a minority of patients.

Systematic review: relationships between sleep and gastro-oesophageal reflux

BACKGROUND

Gastro-oesophageal reflux disease (GERD) adversely impacts on sleep, but the mechanism remains unclear.

AIM

To review the literature concerning gastro-oesophageal reflux during the sleep period, with particular reference to the sleep/awake state at reflux onset.

METHODS

Studies identified by systematic literature searches were assessed.

RESULTS

Overall patterns of reflux during the sleep period show consistently that oesophageal acid clearance is slower, and reflux frequency and oesophageal acid exposure are higher in patients with GERD than in healthy individuals. Of the 17 mechanistic studies identified by the searches, 15 reported that a minority of reflux episodes occurred during stable sleep, but the prevailing sleep state at the onset of reflux in these studies remains unclear owing to insufficient temporal resolution of recording or analysis methods. Two studies, in healthy individuals and patients with GERD, analysed sleep and pH with adequate resolution for temporal alignment of sleep state and the onset of reflux: all 232 sleep period reflux episodes evaluated occurred during arousals from sleep lasting less than 15 s or during longer duration awakenings. Six mechanistic studies found that transient lower oesophageal sphincter relaxations were the most common mechanism of sleep period reflux.

CONCLUSIONS

Contrary to the prevailing view, subjective impairment of sleep in GERD is unlikely to be due to the occurrence of reflux during stable sleep, but could result from slow clearance of acid reflux that occurs during arousals or awakenings from sleep. Definitive studies are needed on the sleep/awake state at reflux onset across the full GERD spectrum.

The relevance of transient lower oesophageal sphincter relaxations in the pathophysiology and treatment of GORD

Gastro-oesophageal reflux disease (GORD) is associated with the passage of gastric contents into the oesophagus resulting in potential oesophageal damage and impaired quality of life. GORD is a frequently encountered problem in today's population, with 25% of people in western populations reporting such symptoms at least once a month. Proton pump inhibitors (PPI) are the drug of choice, with surgery being employed in refractory cases. Although acid suppression is often effective, some patients remain symptomatic despite maximal PPI therapy. By delving into the mechanisms of the disease, it is clear that transient lower oesophageal sphincter relaxations are a key component of its pathophysiology. Research has demonstrated various therapeutic targets for reducing the frequency of such relaxations through GABA and glutamate modulation, for instance. This review highlights such modulations and hopes to explore these mechanisms and therapeutic targets in an area that will no doubt see a change in its pharmacological management in the near future.

Gastroesophageal reflux in patients treated for congenital diaphragmatic hernia: short- and long-term evaluation with multichannel intraluminal impedance

PURPOSE

The incidence of GER, related symptoms and complications in patients treated for congenital diaphragmatic hernia (CDH) are poorly defined. The aim was to evaluate incidence and development of GER in children treated for CDH in a short- and long-term follow-up period, identifying potential risk factors of morbidity.

METHODS

Thirty-six patients were evaluated with pH-MII at a median age of 6 months (T1) and re-evaluated with pH-MII and endoscopy at a median age of 5 years (T2).

RESULTS

The incidence of reflux was 83 % in T1 and 61 % in T2; the incidence of symptoms was 62 % in T1 and 38 % in T2. In both groups the reflux was mainly non-acidic. Patch, intrathoracic stomach and esophageal dysmotility were risk factors for GER.

CONCLUSIONS

The incidence of GER and symptoms decrease over the time but it was higher than in the literature, probably because it is mainly non-acidic and evaluable only with MII. The esophageal dysmotility was found to be the main risk factor. An high incidence of reflux and esophagitis was found also in asymptomatic patients, and so a close follow-up is recommended in all patients even if it is asymptomatic.

Systematic review: patterns of reflux-induced symptoms and esophageal endoscopic findings in large-scale surveys

BACKGROUND & AIMS

This systematic review assesses findings of endoscopic surveys in the general population with regard to gastroesophageal reflux disease (GERD).

METHODS

Systematic searches were conducted in PubMed and EMBASE. Authors were contacted for additional, unpublished data.

RESULTS

Data on 61,281 individuals were included from 3 general population studies (Kalixanda study [Sweden], Loiano-Monghidoro study [Italy], SILC study [China]) and 8 health-check studies (Japan, n = 1; China, n = 1; Taiwan, n = 4; Korea, n = 2). The prevalence of reflux esophagitis was 15.5% (Kalixanda), 11.8% (Loiano-Monghidoro), and 6.4% (SILC); it ranged from 3.4% to 8.5% in health-check studies in Japan, China, and Korea (n = 4), but was higher (mean, 15.6%; range, 9.0%-24.6%; n = 4) in Taiwan. Hiatus hernia prevalence was 23.9% (Kalixanda), 43.0% (Loiano-Monghidoro), and 0.7% (SILC), and 0.8%-19.5% in health-check studies (n = 7). For endoscopically suspected esophageal metaplasia (ESEM), the prevalence was 10.3% (Kalixanda), 3.6% (Loiano-Monghidoro), and 1.8% (SILC), and 0.0%-3.4% in health-check studies (n = 4). The prevalence of reflux esophagitis among individuals without symptom-defined GERD was 12.1% (Kalixanda), 8.6% (Loiano-Monghidoro), 6.1% (SILC), and 1.6%-22.8% (health-check studies; n = 6). For individuals without symptom-defined GERD, the prevalence of ESEM was 9.4% (Kalixanda), 2.8% (Loiano-Monghidoro), and 1.8% (SILC).

CONCLUSIONS

The prevalence of reflux esophagitis is higher in Sweden and Italy than in China, Korea, and Japan, but is within the range reported in Taiwan. Hiatus hernia and ESEM are generally more prevalent in Europe than in Asia. A considerable proportion of individuals without symptom-defined GERD has reflux esophagitis or ESEM.

Gastro-oesophageal reflux disease is associated with up-regulation of desmosomal components in oesophageal mucosa

AIMS

Gastro-oesophageal reflux disease (GERD) is associated with impaired epithelial barrier function. This study was aimed at investigating the role of desmosomal proteins in relation to GERD.

METHODS AND RESULTS

Ninety-five patients with GERD-related symptoms (erosive, n = 51; non-erosive, n = 44) and 27 patients lacking those symptoms were included. Endoscopic and histological characterization of oesophagitis was performed according to the Los Angeles and Ismeil-Beigi criteria, respectively. Multiple biopsies were taken from the oesophageal mucosa of each patient. Gene expression analysis of plakoglobin, desmoglein-1, desmoglein-2 and desmoglein-3 was performed by quantitative real time (RT)-polymerase chain reaction and immunohistochemistry in the oesophageal mucosa. Routine histology revealed specific GERD-related alterations, such as dilatation of intercellular spaces (DIS), basal cell hyperplasia (BCH), and elongation of the papillae, in the oesophageal mucosa of patients with GERD, as compared with controls (all parameters: P < 0.05). All four genes and corresponding proteins were found to be up-regulated by between 1.7 and 8.1-fold (transcript level, P < 0.05; protein level, P < 0.05). Induced gene expression levels of plakoglobin, desmoglein-1 and desmoglein-2 correlated significantly with DIS and BCH.

CONCLUSIONS

Taken together, the uniform up-regulation of desmosomal genes/proteins in the oesophageal mucosa of patients with GERD supports the concept of architectural and molecular changes in the desmosomal compartment in the pathogenesis of GERD.

Gestational age at birth and risk of gastric acid-related disorders in young adulthood

PURPOSE

Preterm birth is associated with gastric acid-related disorders in infancy, but no investigators have examined this association beyond early childhood. We used antisecretory medication data to explore whether preterm birth is associated with gastric acid-related disorders in young adulthood.

METHODS

We conducted a national cohort study of 626,811 individuals born in Sweden in 1973 to 1979, followed up for antisecretory (proton pump inhibitor and H2-receptor antagonist) medication prescriptions from all outpatient and inpatient pharmacies nationwide from 2005 to 2009 (ages 25.5-37.0 years). We excluded individuals with congenital anomalies, and examined potential confounding by other comorbidities identified on the basis of oral anti-inflammatory or corticosteroid medication prescription.

RESULTS

Gestational age at birth was inversely associated with antisecretory medication prescription in young adulthood. Adjusted odds ratios for ≥1 antisecretory medication prescription/year were 3.38 (95% confidence interval [95% CI], 1.73-6.62) for individuals born at 22-27 weeks, 1.38 (95% CI, 1.19-1.60) for those born at 28-34 weeks, and 1.19 (95% CI, 1.06-1.32) for those born at 35-36 weeks, relative to those born full-term (37-42 weeks). Exclusion of individuals who were prescribed oral anti-inflammatory or corticosteroid medications (≥1/year) had little effect on these results.

CONCLUSIONS

These findings suggest that low gestational age at birth may be independently associated with an increased risk of gastric acid-related disorders in young adulthood.

Impedance-pH reflux patterns can differentiate non-erosive reflux disease from functional heartburn patients

INTRODUCTION

Symptom association is important to distinguish non-erosive reflux disease [NERD; abnormal oesophageal acid exposure time (AET) and/or positive symptom association] from functional heartburn (FH; normal AET and negative symptom association). Asymptomatic patients during reflux monitoring are challenging as symptom association cannot be assessed.

AIM

To evaluate whether impedance-pH reflux patterns are useful to differentiate NERD from FH.

METHODS

Endoscopy-negative reflux patients underwent impedance-pH off-therapy. Oesophageal AET, characteristics of reflux episodes and symptom association probability (SAP) were measured. Twenty patients asymptomatic during the first test repeated a second examination.

RESULTS

Of 329 patients, 130 (40%) were pH-POS, 120 (36%) pH-NEG/SAP+ (hypersensitive oesophagus = HO) and 79 (24%) pH-NEG/SAP- (FH). Total and acid reflux episodes were significantly higher (p < 0.01) in pH-POS compared to pH-NEG/SAP+, pH-NEG/SAP- and healthy volunteers (HVs). Patients pH-NEG/SAP+ had a significantly increased number of weakly acidic reflux episodes compared to pH-POS, pH-NEG/SAP- and HVs (p < 0.01). The rate of proximal reflux episodes in pH-POS (50%) and pH-NEG/SAP+ (47%) was higher (p < 0.01) than in pH-NEG/SAP- (33%) and HVs (33%). Measuring AET, number of reflux episodes and percentage of proximal reflux events permits to identify FH in 70% of cases and HO in 80% of cases who repeated the examination.

CONCLUSION

In patients with normal AET and SAP+, increased number of weakly acidic reflux and higher rate of proximal reflux are the main discriminant features. There is large overlap between FH and HVs. These differences can be of help in diagnosing patients with normal oesophageal acid exposure who fail to have symptoms during MII-pH testing.

In vitro effect of pantoprazole on lower esophageal sphincter tone in rats

AIM: To investigate the in vitro effects of pantoprazole on rat lower esophageal sphincter (LES) tone.

METHODS: Rats weighing 250-300 g, provided by the Yeditepe University Experimental Research Center (YÜDETAM), were used throughout the study. They were anesthetized before decapitation. LES tissues whose mucosal lining were removed were placed in a standard 30-mL organ bath with a modified Krebs solution and continuously aerated with 95% oxygen-5% carbon dioxide gas mixture and kept at room temperature. The tissues were allowed to stabilize for 60 min. Subsequently, the contractile response to 10^-6 mol/L carbachol was obtained. Different concentrations of freshly prepared pantoprazole were added directly to the tissue bath to generate cumulative concentrations of 5 × 10^-6 mol/L, 5 × 10^-5 mol/L, and 1.5 × 10^-4 mol/L. Activities were recorded on an online computer via a 4-channel transducer data acquisition system using the software BSL PRO v 3.7, which also analyzed the data.

RESULTS: Pantoprazole at 5 × 10^-6 mol/L caused a small, but statistically insignificant, relaxation in the carbachol-contracted LES (2.23% vs 3.95%). The 5 × 10^-5 mol/L concentration, however, caused a significant relaxation of 10.47% compared with the control. 1.5 × 10^-4 mol/L concentration of pantoprazol caused a 19.89% relaxation in the carbachol contracted LES (P < 0.001).

CONCLUSION: This is the first study to demonstrate that pantoprazole has a relaxing effect in isolated LESs. These results might have significant clinical implications for the subset of patients using proton pump inhibitors who do not receive full symptomatic alleviation from gastroesophageal reflux disease.

High-resolution esophageal pressure topography is superior to conventional sleeve manometry for the detection of transient lower esophageal sphincter relaxations associated with a reflux event

BACKGROUND

Transient lower esophageal sphincter relaxations (TLESRs) are the main mechanism underlying gastro-esophageal reflux and are detected during manometric studies using well defined criteria. Recently, high-resolution esophageal pressure topography (HREPT) has been introduced and is now considered as the new standard to study esophageal and lower esophageal sphincter (LES) function. In this study we performed a head-to-head comparison between HREPT and conventional sleeve manometry for the detection of TLESRs.

METHODS

A setup with two synchronized MMS-solar systems was used. A solid state HREPT catheter, a water-perfused sleeve catheter, and a multi intraluminal impedance pH (MII-pH) catheter were introduced in 10 healthy volunteers (M6F4, age 19-56). Subjects were studied 0.5 h before and 3 h after ingestion of a standardized meal. Tracings were blinded and analyzed by the three authors according to the TLESR criteria.

KEY RESULTS

In the HREPT mode 156 TLESRs were scored, vs 143 during sleeve manometry (P = 0.10). Hundred and twenty-three TLESRs were scored by both techniques. Of all TLESRs (177), 138 were associated with reflux (78%). High-resolution esophageal pressure topography detected significantly more TLESRs associated with a reflux event (132 vs 119, P = 0.015) resulting in a sensitivity for detection of TLESRs with reflux of 96% compared to 86% respectively. Analysis of the discordant TLESRs associated with reflux showed that TLESRs were missed by sleeve manometry due to low basal LES pressure (N = 5), unstable pharyngeal signal (N = 4), and residual sleeve pressure >2 mmHg (N = 10).

CONCLUSIONS & INFERENCES

The HREPT is superior to sleeve manometry for the detection of TLESRs associated with reflux. However, rigid HREPT criteria are awaited.

Systematic review: ageing and gastro-oesophageal reflux disease symptoms, oesophageal function and reflux oesophagitis

BACKGROUND

Gastro-oesophageal reflux disease (GERD) is thought to become more prevalent with age.

AIM

To assess systematically how age affects the prevalence of GERD and its oesophageal complications.

METHODS

Systematic PubMed searches were used to identify population-based studies on the age-related prevalence and incidence of GERD, and clinical studies on age-related changes in oesophageal complications in GERD.

RESULTS

Nine population-based studies and seven clinical studies met the inclusion criteria. Four of seven prevalence studies observed no significant effect of age on GERD symptom prevalence, two did not report on statistical significance and one observed a significant age-related increase in symptom prevalence. The two population-based endoscopic surveys showed no significant effect of age on reflux oesophagitis prevalence. Clinical studies in patients with GERD showed an increase in reflux oesophagitis severity and a decrease in heartburn severity with age, and age-related increases in oesophageal acid exposure and anatomical disruption of the gastro-oesophageal junction.

CONCLUSIONS

Epidemiological studies do not show an increase in GERD symptom prevalence with age. However, in individuals with GERD, ageing is associated with more severe patterns of acid reflux and reflux oesophagitis; despite this, symptoms associated with GERD become less severe and more nonspecific with ageing. Thus, the real prevalence of GERD may well increase with age.

Identifying the Ion Channels Responsible for Signaling Gastro-Intestinal Based Pain

We are normally unaware of the complex signalling events which continuously occur within our internal organs. Most of us only become cognisant when sensations of hunger, fullness, urgency or gas arise. However, for patients with organic and functional bowel disorders pain is an unpleasant and often debilitating reminder. Furthermore, chronic pain still represents a large unmet need for clinical treatment. Consequently, chronic pain has a considerable economic impact on health care systems and the afflicted individuals. In order to address this need we must understand how symptoms are generated within the gut, the molecular pathways responsible for generating these signals and how this process changes in disease states.

Effect of lesogaberan, a novel GABA(B)-receptor agonist, on transient lower oesophageal sphincter relaxations in male subjects

BACKGROUND

Transient lower oesophageal sphincter relaxations (TLESRs) are a major mechanism behind gastro-oesophageal reflux disease (GERD).

AIM

To assess the effect of lesogaberan (AZD3355) - a novel peripherally active GABA(B) receptor agonist - on TLESRs.

METHODS

Twenty-four healthy men were enrolled in this single-blind, placebo-controlled, randomized, single-centre, three-period crossover phase 1 study. Subjects were randomized to receive single oral doses of lesogaberan (0.8 mg/kg), baclofen (40 mg) and placebo, separated by washout periods of < or = 7 days. Subjects finished a meal 1 h after the dose. Oesophageal manometry and pH-metry measurements were taken during the 3 h after the meal.

RESULTS

Twenty-one subjects completed the study. Compared with placebo, lesogaberan 0.8 mg/kg significantly reduced the number of TLESRs by 36% [geometric mean ratio (GMR): 0.64; 95% confidence interval (CI): 0.51-0.82] and significantly reduced the number of acid reflux episodes (mean reduction: 1.6; 95% CI: 0.34-2.9). Lesogaberan also significantly increased lower oesophageal sphincter (LES) pressure by 39% compared with placebo (GMR: 1.39; 95% CI: 1.18-1.64). Comparable results were observed with baclofen. Similar numbers of adverse events were reported by subjects taking lesogaberan and placebo.

CONCLUSION

Compared with placebo, lesogaberan significantly reduced TLESRs and acid reflux episodes and increased LES pressure.

Gastroesophageal reflux disease in children and adolescents in primary care

OBJECTIVES

To determine the prevalence and incidence of a diagnosis of gastroesophageal reflux disease (GERD) in children and adolescents in UK primary care, and to assess comorbidities that are associated with a diagnosis of GERD.

MATERIAL AND METHODS

Incident GERD cases during 2000-05 were identified from The Health Improvement Network (THIN) UK primary care database via a computer search for diagnostic codes for GERD, followed by manual review of the patient records.

RESULTS

We identified 1700 children with a first diagnosis of GERD during 2000-05. The incidence of GERD was 0.84 per 1000 person-years. The incidence decreased with age from 1.48 per 1000 person-years among 1-year-old children until the age of 12 years, whereupon it increased to a maximum at 16-17 years of 2.26 per 1000 person-years for girls and 1.75 per 1000 person-years for boys. Pregnant adolescents were not included in the study. In addition to typical GERD symptoms (epigastric pain, heartburn, reflux, regurgitation), 21.2% of children reported nausea or vomiting. Children with neurological disorders were at increased risk of a GERD diagnosis. Hiatus hernia and congenital esophageal disorders were also associated with a diagnosis of GERD. Children and adolescents using antiepileptics, oral/inhaled steroids, beta-agonists and paracetamol had an increased risk of a GERD diagnosis.

CONCLUSIONS

The incidence of a GERD diagnosis was age-dependent and was highest among very young children and older female adolescents. Children with neurological impairments and other comorbidities were at increased risk of a GERD diagnosis.

The novel, peripherally restricted GABAB receptor agonist lesogaberan (AZD3355) inhibits acid reflux and reduces esophageal acid exposure as measured with 24-h pHmetry in dogs

While patients with symptoms of gastroesophageal reflux disease generally respond well to proton pump inhibitors, 20-30% continue to experience troublesome symptoms. In such cases, agents that target transient lower esophageal sphincter (LES) relaxation may be useful as add-on therapy to proton pump inhibitors. The GABAB receptor agonist baclofen inhibits transient LES relaxation but it is not an ideal agent due to central nervous system activity. Lesogaberan (AZD3355) is a peripherally restricted GABAB receptor agonist with limited central nervous system activity that inhibits transient LES relaxation in dogs. In the present study, the comparative effects of lesogaberan (7 micromol/kg) and baclofen (2.8 micromol/kg) on reflux were studied in dogs using 24-h pHmetry. Drugs (or vehicle control) were administered orally prior to the first meal of the day, and the number of reflux episodes (pH<4 for > or = 5 s) and acid exposure time were computed for the 24-h monitoring period. The mean (S.E.M.) number of reflux episodes/24 h was 4.6 (0.4) and 6.4 (0.6) for lesogaberan and baclofen, respectively, versus 10.7 (0.5) for control (P<0.0001 for both). Acid exposure time was 51.2 (4.5) min for control versus 23.6 (3.8) min for lesogaberan (P<0.0001) and 35.4 (6.5) min with baclofen (P=0.05). It is concluded that lesogaberan significantly reduces acid reflux in dogs, with comparable efficacy to baclofen.

Subcardial 24-h wireless pH monitoring in gastroesophageal reflux disease patients with and without hiatal hernia compared with healthy subjects

OBJECTIVES

After meals, highly acidic gastric juice is present in the subcardial region, the so-called acid pocket. Patients with gastroesophageal reflux disease (GERD) have a higher frequency of acidic reflux. Our aim was to investigate the possible differences in subcardial pH in GERD over 24 h and the role of hiatal hernia (HH), using a wireless capsule.

METHODS

A total of 14 healthy volunteers (4 men, 24-60 years), 10 GERD patients without HH (4 men, 25-68 years), and 11 GERD patients with HH >or=3 cm (2 men, 46-74 years) underwent 24-h wireless pH monitoring 2 cm below the squamocolumnar junction. All patients had increased 24-h acid reflux. A standardized lunch was given to all study subjects.

RESULTS

No capsule detached during the 24-h recording. Median 24-h pH was similar in healthy subjects, and in patients without and with HH, median: 1.4 (interquartile range: 1.2 -1.9), 1.5 (1.3 -1.7), and 1.4 (1.3 -1.7), respectively. Similar results were seen in the supine period. Median pH after the standardized meal was often highly acidic, 2.7 (1.5 - 3.2), 1.9 (1.6 - 2.3), and 2.5 (1.6 - 3.2), respectively. The first minute with a median pH <2 occurred 14 min (4 - 49), 14 min (6 - 25), and 20 min (4 - 43), respectively, P=NS, after the end of the meal. Similar data were observed on pooling all meals together.

CONCLUSIONS

Subcardial pH is confirmed to be highly acidic early after meals, but it is similar over 24 h in healthy subjects and GERD patients independent of the presence of HH.

Landmarks in the understanding and treatment of reflux disease

The last 50 years have seen a transformation in the understanding and treatment of reflux disease. The development and wide use of flexible endoscopy and progressively more sophisticated approaches to measurement of pathophysiological factors have been major drivers of advances. The recognition and progressive elucidation of the mechanical events that comprise the transient lower esophageal sphincter relaxation and how they lead to reflux provide a novel and firm foundation for tailoring therapies that act directly to reduce occurrence of reflux episodes, either surgically or pharmacologically. Novel GABA(B) agonist drugs have been shown to inhibit transient relaxations and are currently being evaluated in clinical trials on patients with reflux disease. Better understanding has extended to recognition of the extraordinarily high prevalence of reflux disease and of the ability of proton pump inhibitor drugs to deliver major benefits to a high proportion of patients with reflux disease. The life of the Gastroenterological Society of Australia has spanned the period of these major advances. A large number of the members of the Society and their associates have contributed substantially to these advances.

Evolving issues in the management of reflux disease?

PURPOSE OF REVIEW

Gastroesophageal reflux disease (GERD) is a common chronic disorder often successfully treated, although there are several evolving issues in management. We reviewed the issues related to unmet needs over the past 12 months.

RECENT FINDINGS

A substantial number of patients fail to respond adequately to once or even twice daily proton pump inhibitor (PPI). There is no standard definition of PPI failure in GERD; a universally accepted definition for treatment success is also not available. Differentiation between erosive esophagitis and nonerosive reflux disease can be made but requires endoscopy; but studies still confuse functional heartburn and nonerosive reflux disease, which impacts management. Acid reflux plays an important role in GERD pathogenesis and the precise role of acid requires more studies of differences between erosive esophagitis and nonerosive reflux disease symptom generation and the implication of nocturnal acidification. Several possible mechanisms may explain GERD refractory to PPIs.

SUMMARY

Management of PPI nonresponders remains a challenge. Objective and precise evaluation of symptoms and treatment response requires study in high-quality trials. New therapeutic approaches are under investigation to answer unmet needs and improve erosive esophagitis healing rates and symptom control.

Zonulin is not increased in the cardiac and esophageal mucosa of patients with gastroesophageal reflux disease

Human Zonulin, related to the Zonula occludens toxin of Vibrio cholerae, regulates intestinal permeability and is induced in inflammatory disorders of the lower GI tract. Gastroesophageal reflux disease (GERD) is associated with an impairment of epithelial barrier function. Here, we studied expression of zonulin in the gastroesophageal mucosa of 58 patients with typical reflux symptoms and 27 asymptomatic controls. During endoscopy, multiple biopsies from gastroesophageal mucosa were obtained for routine histopathology (Helicobacter pylori-status, inflammation) and gene expression analysis (immunohistochemistry, ELISA). Patients with GERD presented with typical histopathological alterations like elongation of papillae (P=0.015), basal cell hyperplasia (P<0.001) and dilatation of intercellular spaces (P=0.002). Zonulin was found to be expressed ubiquitously in gastroesophageal mucosa. Mucosal levels in controls ranged between 2.2 and 3.7 ng/microg total protein. Mean values were significantly higher in antrum (3.3+/-1.7 ng/microg) than cardia (2.7+/-1.2n g/microg) and esophagus (2.2+/-1.3 ng/microg) (P<0.001), but did not differ between GERD and controls for cardia and esophageal mucosa. Immunohistochemistry revealed that predominantly epithelial cells but not stromal cells contribute to the zonulin expression in gastroesophageal mucosa. In conclusion, despite its established role for intestinal permeability, Zonulin seems not to be involved in the regulation of epithelial barrier function in relation to GERD.

Expression of inducible nitric oxide synthase and heme oxygenase-1 in the esophageal mucosa of patients with reflux esophagitis

AIM: To detect the expression of inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1) in human esophageal mucosa of patients with reflux esophagitis (RE), and to find out the role of gas messenger molecules such as nitric oxide (NO) and carbon monoxide (CO) in the pathogenesis of RE.

METHODS: The distributions of iNOS and HO-1 proteins in esophageal tissues 77 RE patients and 20 normal controls were detected by immunohistochemistry (SP method), and the relationship between iNOS and HO-1 expression was analyzed.

RESULTS: iNOS and HO-1 were expressed mainly in esophageal mucosal epithelia. The expression levels of iNOS and HO-1 in RE patients were significantly higher than those in the normal controls (0.2473 ± 0.0548 vs 0.1616 ± 0.0169; 0.2334 ± 0.0511 vs 0.1776 ± 0.0164; both P < 0.01). Moreover the expression of HO-1 was positively correlated with iNOS expression in esophageal mucosa of RE patients (r = 0. 513, P = 0.000). There was no marked difference between iNOS and NO expression in the normal controls (r = -0.073, P = 0.758).

CONCLUSION: HO-1 and iNOS are abnormally expressed in esophageal mucosa of RE patients, suggesting that NO and CO may play important roles in the pathogenesis of gastrointestinal motility disorders such as RE.