Mechanisms of gastroesophageal reflux in patients with reflux esophagitis

Acid reflux directly causes sleep disturbances in rat with chronic esophagitis

BACKGROUND & AIMS

Gastroesophageal reflux disease (GERD) is strongly associated with sleep disturbances. Proton pump inhibitor (PPI) therapy improves subjective but not objective sleep parameters in patients with GERD. This study aimed to investigate the association between GERD and sleep, and the effect of PPI on sleep by using a rat model of chronic acid reflux esophagitis.

METHODS

Acid reflux esophagitis was induced by ligating the transitional region between the forestomach and the glandular portion and then wrapping the duodenum near the pylorus. Rats underwent surgery for implantation of electrodes for electroencephalogram and electromyogram recordings, and they were transferred to a soundproof recording chamber. Polygraphic recordings were scored by using 10-s epochs for wake, rapid eye movement sleep, and non-rapid eye movement (NREM) sleep. To examine the role of acid reflux, rats were subcutaneously administered a PPI, omeprazole, at a dose of 20 mg/kg once daily.

RESULTS

Rats with reflux esophagitis presented with several erosions, ulcers, and mucosal thickening with basal hyperplasia and marked inflammatory infiltration. The reflux esophagitis group showed a 34.0% increase in wake (232.2±11.4 min and 173.3±7.4 min in the reflux esophagitis and control groups, respectively; p<0.01) accompanied by a reduction in NREM sleep during light period, an increase in sleep fragmentation, and more frequent stage transitions. The use of omeprazole significantly improved sleep disturbances caused by reflux esophagitis, and this effect was not observed when the PPI was withdrawn.

CONCLUSIONS

Acid reflux directly causes sleep disturbances in rats with chronic esophagitis.

Effects of mosapride on esophageal motor activity and esophagogastric junction compliance in healthy volunteers

BACKGROUND

The effects of the prokinetic drug mosapride on esophageal motor activity vary at standard doses. In addition to esophageal motor activities, compliance of the esophagogastric junction (EGJ) is important for prevention of gastroesophageal reflux. However, the effects of mosapride on EGJ compliance have not been reported. Here, we investigated the effects of high-dose mosapride on esophageal motor activities and EGJ compliance.

METHODS

Nine healthy volunteers were enrolled in the study. Peristaltic esophageal contraction and lower esophageal sphincter pressures before and after administration of 40 mg mosapride were examined by high resolution esophageal manometry. Esophageal compliance was also investigated by intra-esophageal impedance planimetry (EndoFLIP(®)).

RESULTS

High-dose mosapride augmented peristaltic contractions, especially in the distal esophageal segments (P < 0.05). The mean resting lower esophageal sphincter pressure was elevated from 25.0 mmHg before administration to 28.9 mmHg after (P < 0.05). In addition, mosapride significantly reduced EGJ compliance (P < 0.05).

CONCLUSIONS

Mosapride at 40 mg augmented esophageal motor activities and reduced EGJ compliance in healthy volunteers.

Dysmotility and reflux disease

PURPOSE OF REVIEW

In the last decade, with the advent of new oesophageal testing [i.e. 24-h impedance-pH monitoring, combined impedance-manometry, high-resolution manometry (HRM)], relevant progress in understanding the mechanisms contributing to the development of gastro-oesophageal reflux disease (GORD) has been made, allowing a better management of patients with this disorder. The aim of our review is to report the state-of-the-art about oesophageal motor disorders in patients with reflux disease and to stimulate new research in this field.

RECENT FINDINGS

Hypotensive lower oesophageal sphincter (LOS), transient LOS relaxations, impairment of oesophagogastric junction including hiatal hernia, oesophageal bolus transit abnormalities and presence of ineffective oesophageal motility have been strongly implicated in GORD development. In particular, the majority of recent studies carried out with HRM and impedance-pH testing reported that these motor abnormalities are increasingly prevalent with increasing severity of GORD, from nonerosive reflux disease and erosive oesophagitis to Barrett's oesophagus.

SUMMARY

Defining and characterizing oesophageal dysmotility in patients with reflux disease is of maximum importance in order to properly diagnose these patients and to treat them with the best management of care. New studies are needed in order to better understand the physiomechanic basis of oesophageal dysmotility in GORD patients.

The University of Chicago contribution to the treatment of gastroesophageal reflux disease and its complications: a tribute to David B. Skinner 1935-2003

OBJECTIVE

To highlight the contributions from the University of Chicago under the leadership of Dr David B. Skinner to the understanding of gastroesophageal reflux disease (GERD) and its complications.

BACKGROUND

The invention of the esophagoscope confirmed that GERD was a premorbid condition. The medical world was divided between those who believed in a morphological lower esophageal sphincter (LES) and those who did not. Those who did not believe attempted to rearrange the anatomy of the foregut organs to stop reflux with minimal success. The discovery of the LES focused attention on the sphincter as the main deterrent to reflux and the hope that measurement of a low LES pressure would mark the presence of GERD. This turned out not to be so. In July 1973, with this history of confusion, Dr Skinner at the age of 36 assumed the chair of surgery at the University of Chicago.

METHODS

The publications of the University of Chicago's esophageal group were collected from private and public (PubMed) databases, reviewed, and seminal contributions selected.

RESULTS

Twenty-four-hour esophageal pH monitoring led to the understanding of the LES, its contribution to GERD, and the complication of Barrett's esophagus. The relationship of Barrett's to adenocarcinoma was clarified. The rising incidence of esophageal adenocarcinoma led to contributions in the staging of esophageal cancer and its treatment with an en bloc resection.

CONCLUSIONS

Ten years after the death of Dr Skinner, we can appreciate the monumental contributions to benign and malignant esophageal disease under his leadership.

Dinner-to-bed time and post-dinner walk: new potential independent factors in esophageal cancer development

PURPOSE

Esophageal squamous cell carcinoma (ESCC) remains a significant cause of morbidity and mortality worldwide. The aim of the study was to investigate the effects of shorter dinner-to-bed time and post-dinner walk on ESCC risk.

METHODS

A matched case-control study with 232 ESCC patients and 286 age- and gender-matched healthy controls enrolled was conducted. Conditional logistic regression was used to calculated odds ratio (OR) and 95 % confidence intervals (95 % CI).

RESULTS

The adjusted ORs of ESCC for subjects with shorter dinner-to-bed time (<3 h) were 2.84 (95 % CI 1.64-4.29), relative to those with longer dinner-to-bed time (≥4 h). While post-dinner walk was associated with a decreased ESCC risk (adjusted OR 0.64; 95 % CI 0.41-0.89). What's more, when reflux symptom was added into the multivariate models, risk estimate for shorter dinner-to-bed time still remained statistically significant (p = 0.003), and risk estimate for post-dinner walk changed slightly. In the subgroup analysis stratified by post-dinner walk, subjects with shorter dinner-to-bed time experienced similar risk (adjusted ORs 2.71 vs. 2.82).

CONCLUSIONS

Shorter dinner-to-bed time is a potential risk factor for ESCC and post-dinner walk is a protective factor, providing evidence for the effect of lifestyle factors on ESCC risk.

Proton pump inhibitors for reflux therapy in infants: effectiveness determined by impedance pH monitoring

PURPOSE

To evaluate the influence of proton pump inhibitors (PPI) in predominantly milk-fed infants with symptoms of GERD by 24-h pH-multichannel intraluminal impedance (24-h pH-MII).

METHODS

Ten infants (8 males and 2 females) with a mean gestational age of 39 weeks (28-40) were included. 24-h pH-MII was performed before prescription and during intake of PPI. Total acid exposure time, bolus exposure time (acidic/non-acidic/total) and the number of refluxes (acidic/non-acidic/total) were determined. Clinical symptoms were recorded and used to calculate the Reflux Symptom Index (RSI) and the Symptom Severity Index (SSI).

RESULTS

There was a significant decrease in the number of acidic refluxes, total acid exposure and acidic bolus exposure time. However, this went along with a significant increase in non-acidic bolus exposure time. The total number of refluxes and the total bolus exposure time remained unchanged. Under PPI, a decrease of SSI and RSI for pain-related symptoms could be observed. For respiratory symptoms and vomiting however no significant changes could be demonstrated.

CONCLUSIONS

Under PPI, an improvement of pain-related symptoms could be shown. The decrease of acid exposure went along with an increase of non-acidic refluxes resulting in almost constant total reflux numbers. This finding is interpreted as main reason for some persisting symptoms despite adequate PPI dosage. Concluding from our data PPI therapy should only be indicated in case of pain, but has no effect in case of vomiting or recurrent respiratory symptoms.

Dickkopf-1, the Wnt antagonist, is induced by acidic pH and mediates epithelial cellular senescence in human reflux esophagitis

Squamous esophageal epithelium adapts to acid reflux-mediated injury by proliferation and differentiation via signal transduction pathways. Induction of the Wnt antagonist Dickkopf-1 (Dkk1) is involved in tissue repair during inflammation and cellular injury. In this study, we aimed to identify the biological role of Dkk1 in human reflux esophagitis with respect to cell growth and regulation of Wnt signaling. Esophageal biopsies from reflux-esophagitis patients (n = 15) and healthy individuals (n = 10) were characterized in terms of Dkk1 expression. The role of Dkk1 in response to acid-mediated epithelial injury was analyzed by cellular assays in vitro utilizing squamous esophageal epithelial cell lines (EPC1-hTERT, EPC2-hTERT, and HEEC). Dkk1 was significantly overexpressed in human reflux-esophagitis tissue compared with healthy esophageal mucosa at transcriptional and translational levels. After acute and chronic acid (pH 4) exposure, esophageal squamous epithelial cell lines expressed and secreted high levels of Dkk1 in response to stress-associated DNA injury. High extracellular levels of human recombinant Dkk1 inhibited epithelial cell growth and induced cellular senescence in vitro, as demonstrated by reduced cell proliferation, G0/G1 cell cycle arrest, elevated senescence-associated β-galactosidase activity, and upregulation of p16. Acid pulsing induced Dkk1-mediated senescence, which was directly linked to the ability of Dkk1 to antagonize the canonical Wnt/β-catenin signaling. In healthy esophageal mucosa, Dkk1 expression was associated with low expression of transcriptionally active β-catenin, while in reflux-esophagitis tissue, Dkk1 overexpression correlated with increased senescence-associated β-galactosidase activity and p16 upregulation. The data indicate that, in human reflux esophagitis, Dkk1 functions as a secreted growth inhibitor by suppressing Wnt/β-catenin signaling and promoting cellular senescence. These findings suggest a significant role for Dkk1 and cellular senescence in esophageal tissue homeostasis during reflux esophagitis.

Enhanced nicotinic receptor mediated relaxations in gastroesophageal muscle fibers from Barrett's esophagus patients

BACKGROUND

Increased nicotinic receptor mediated relaxation in the gastroesophageal antireflux barrier may be involved in the pathophysiology of reflux. This study is designed to determine whether the defects we previously identified in gastroesophageal reflux disease patients in- vivo are due to abnormalities of the gastric sling, gastric clasp, or lower esophageal circular (LEC) muscle fibers.

METHODS

Muscle strips from whole stomachs and esophagi were obtained from 16 normal donors and 15 donors with histologically proven Barrett's esophagus. Contractile and relaxant responses of gastric sling, gastric clasp, or LEC fibers were determined to increasing concentrations of carbachol and to nicotine after inducing maximal contraction to bethanechol. Muscarinic receptor density was measured using subtype selective immunoprecipitation.

KEY RESULTS

Barrett's esophagus gastric sling and LEC fibers have decreased carbachol-induced contractions. Barrett's esophagus sling fibers have decreased M2 -muscarinic receptors and LEC fibers have decreased M3 receptors. Relaxations of all three fiber types are greater in Barrett's esophagus specimens to both high carbachol concentrations and to nicotine following bethanechol precontraction. The maximal response to bethanechol is greater in Barrett esophagus sling and LEC fibers.

CONCLUSIONS & INFERENCES

The increased contractile response to bethanechol in Barrett's specimens indicates that the defect is likely not due to the smooth muscle itself. The enhanced nicotinic receptor mediated response may be involved in greater relaxation of the muscles within the high-pressure zone of the gastroesophageal junction during transient lower esophageal sphincter relaxations and during deglutitive inhibition and may be involved in the pathophysiology of gastroesophageal reflux disease.

Effect of liquid meals with different volumes on gastroesophageal reflux disease

BACKGROUND AND AIM

Patients with gastroesophageal reflux disease (GERD) are often advised to avoid large meals, based on their complaints of increased symptoms after eating too much, and epidemiological evidence of a link between high volume intake and the presence of GERD. However, the precise effects of meal volume on gastroesophageal reflux have not been well studied. We aimed to clarify the effect of meal volume on acid regurgitation and symptoms in patients with GERD.

METHODS

Fifteen patients (10 female, 5 male; mean 54 ± 10 years old) with GERD were studied twice each in random order, during 24 h ambulatory pH monitoring. On one day, they consumed a 600 mL liquid test meal three times (breakfast, lunch, and dinner), and on the other, they consumed a 300 mL test meal six times (breakfast, snack, lunch, snack, dinner, and snack). Gastric fundus and antral areas and antral contractions were measured by transabdominal ultrasound. Symptoms were recorded using questionnaires.

RESULTS

During the 600 mL regimen, there were more reflux episodes (17 ± 4 vs 10 ± 2, P = 0.03) and a greater total acid reflux time (12.5 ± 5.9% vs 5.5 ± 3.6%; P = 0.045) than the 300 mL regimen. Both the cross-sectional area of the gastric fundus (P = 0.024) and the number of antral contractions (P = 0.014) were greater for the 600 mL regimen.

CONCLUSIONS

Larger meals are associated with distension of the gastric fundus and an increase in gastroesophageal reflux when compared with smaller, more frequent meals.

Pathophysiology of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most common digestive diseases in the Western world, with typical symptoms, such as heartburn, regurgitation, or retrosternal pain, reported by 15% to 20% of the general population. The pathophysiology of GERD is multifactorial. Our understanding of these factors has significantly improved in recent years, with increased understanding of the acid pocket and hiatal hernia and how these factors interact. Although our insight has significantly increased over the past years, more studies are required to better understand symptom generation in GERD, especially in patients with therapy-resistant symptoms.

Novel partial 5HT3 agonist pumosetrag reduces acid reflux events in uninvestigated GERD patients after a standard refluxogenic meal: a randomized, double-blind, placebo-controlled pharmacodynamic study

BACKGROUND

Low basal lower esophageal sphincter (LES) pressure and transient LES relaxations are major causes of gastroesophageal reflux disease (GERD). Pumosetrag, a novel selective partial 5HT3 receptor agonist, showed a promising effect on reducing reflux events in health. We aimed to evaluate the effect of pumosetrag on changes in reflux episodes, lower esophageal sphincter pressure (LESP), and specific symptoms in patients with GERD receiving a refluxogenic meal.

METHODS

Patients with GERD, who developed heartburn and/or regurgitation after ingestion of a refluxogenic meal, were randomized to 1 of 3 dose levels of pumosetrag (0.2, 0.5, or 0.8 mg) or placebo. Before and after 7 days of treatment, patients underwent manometry, intraesophageal multichannel, intraluminal impedance and pH after a standard refluxogenic meal.

KEY RESULTS

A total of 223 patients with GERD [125 (56%) women, mean (SD) age = 36 (12) years] were enrolled. No overall treatment effects were detected for the total number of reflux episodes (acidic and weakly acidic) (p > 0.5); however, significant treatment effects (p < 0.05) on the number of acid reflux episodes were observed with lower values on pumosetrag 0.2 mg (10.8 ± 1.1), 0.5 mg (9.5 ± 1.1), and 0.8 mg (9.9 ± 1.1) compared with placebo (13.3 ± 1.1). Significant treatment effects (p < 0.05) were also observed for the percentage of time pH was <4, with less time for pumosetrag at 0.5 mg (10%) and 0.8 mg (10%) compared with placebo (16%).

CONCLUSIONS & INFERENCES

In GERD, the partial 5HT3 agonist pumosetrag significantly reduced the rate of acid reflux events but did not result in a significant change in LESP or symptomatic improvement over a 1-week treatment period.

Effects of mosapride on secondary peristalsis in patients with ineffective esophageal motility

OBJECTIVE. Ineffective esophageal motility is frequently found in patients with gastroesophageal reflux diseases. Secondary peristalsis contributes to esophageal acid clearance. Mosapride improves gastrointestinal (GI) motility by acting on 5-hydroxytrypatamine4 receptors. The authors aimed to evaluate the effect of mosapride on secondary peristalsis in patients with ineffective esophageal motility. MATERIAL AND METHODS. After recording primary peristalsis baseline, secondary peristalsis was stimulated by slowly and rapidly injecting mid-esophageal air in 18 patients. Two separate experiments were randomly performed with 40 mg oral mosapride or placebo. RESULTS. Mosapride had no effect on the threshold volume of secondary peristalsis during slow air distension (9.8 ± 0.97 vs. 10.2 ± 1.0 mL; p = 0.84), but decreased the threshold volume during rapid air distension (4.1 ± 0.2 vs. 4.6 ± 0.3 mL; p = 0.001). The efficiency of secondary peristalsis during rapid air distension increased with mosapride (70% [40-95%]) compared with placebo (60% [10-85%]; p = 0.0003). Mosapride had no effect on the amplitudes of distal pressure wave of secondary peristalsis during slow (94.3 ± 9 vs. 101.9 ± 9.1 mmHg; p = 0.63) or rapid air distension (89.3 ± 9 vs. 95.2 ± 8.3 mmHg; p = 0.24). CONCLUSIONS. Mosapride improves esophageal sensitivity of secondary peristalsis by abrupt air distension but has limited effect on the motor properties of secondary peristalsis in ineffective esophageal motility patients. Despite its well-known prokinetic effect, mosapride enhances the efficiency of secondary peristalsis in patients with ineffective esophageal motility through augmenting esophageal sensitivity instead of motility.

Therapeutic efficacy of baclofen in refractory gastroesophageal reflux-induced chronic cough

AIM: To evaluate the efficacy and safety of baclofen for treatment of refractory gastroesophageal reflux-induced chronic cough (GERC) unresponsive to standard anti-reflux therapy.

METHODS: Sixteen patients with refractory GERC were given an 8-wk course of baclofen 20 mg three times a day as an add-on therapy to omeprazole. Changes in the cough symptom score, cough threshold to capsaicin, reflux symptom score and possible adverse effects were determined after treatment. The variables of multi-channel intraluminal impedance combined with pH monitoring were compared between responders and non-responders to baclofen.

RESULTS: Twelve of 16 patients completed treatment. Cough disappeared or improved in 56.3% (9/16) of patients, including 6 patients with acid reflux-induced cough (66.7%) and 3 patients with non-acid reflux-induced cough (33.3%). With baclofen treatment, the cough symptom score began to decrease at week 2, was clearly decreased at week 6 and reached a minimum at week 8. At the end of therapy, the lowest concentration of capsaicin required for induction of ≥ 2 and ≥ 5 coughs increased from 0.98 (1.46) to 1.95 (6.82) μmol/L (Z = -2.281, P = 0.024) and from 1.95 (7.31) to 7.8 (13.65) μmol/L (Z = -2.433, P = 0.014), respectively, and the reflux symptom score decreased from 8.0 ± 1.6 to 6.8 ± 0.8 (t = 2.454, P = 0.023). The number of acid reflux episodes was significantly lower in responders than in non-responders. The main adverse effects were somnolence, dizziness and fatigue.

CONCLUSION: Baclofen is a useful, but suboptimal treatment option for refractory GERC.

Specific movement of esophagus during transient lower esophageal sphincter relaxation in gastroesophageal reflux disease

Background/Aims

Transient lower esophageal sphincter relaxation (TLESR) is the main mechanism of gastroesophageal reflux disease (GERD). The aim of this study was to investigate the characteristics of transient lower esophageal sphincter movement in patients with or without gastroesophageal reflux by high-resolution manometry (HRM).

Methods

From June 2010 to July 2010, we enrolled 9 patients with GERD (GERD group) and 9 subjects without GERD (control group), prospectively. The manometry test was performed in a semi-recumbent position for 120 minutes following ingestion of a standardized, mixed liquid and solid meal. HRM was used to identify the frequency and duration of TLESR, esophageal shortening length from incomplete TLESR, upper esophageal sphincter (UES) response, and the related esophageal motor responses during TLESR.

Results

TLESR occurred in 33 in the GERD group and 34 in the control group after 120 minutes following food ingestion. Duration of TLESR and length of esophageal shortening did not differ between 2 groups. UES pressure increase during TLESR was mostly detected in patients with GERD, and UES relaxation was observed frequently in the control group during TLESR. TLESR-related motor responses terminating in TLESR were predominantly observed in the control group.

Conclusions

Increased UES pressure was noted frequently in the GERD group, suggesting a mechanism for preventing harmful reflux, which may be composed mainly of fluid on the larynx or pharynx. However, patients with GERD lacked the related motor responses terminating in TLESR to promote esophageal emptying of refluxate.

Evaluation of Esophageal Motor Function With High-resolution Manometry

For several decades esophageal manometry has been the test of choice to evaluate disorders of esophageal motor function. The recent introduction of high-resolution manometry for the study of esophageal motor function simplified performance of esophageal manometry, and revealed previously unidentified patterns of normal and abnormal esophageal motor function. Presentation of pressure data as color contour plots or esophageal pressure topography led to the development of new tools for analyzing and classifying esophageal motor patterns. The current standard and still developing approach to do this is the Chicago classification. While this methodical approach is improving our diagnosis of esophageal motor disorders, it currently does not address all motor abnormalities. We will explore the Chicago classification and disorders that it does not address.

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.

Pathophysiology of gastroesophageal reflux disease

The gastroesophageal junction is structurally complex and functionally designed to ensure the acid secreted by the most proximal gastric mucosa flows towards the stomach and not up onto the oesophageal squamous mucosa. The pattern and mechanism of reflux vary with the severity of reflux disease and this probably represents different ends of a spectrum rather than distinct pathophysiological mechanisms. Nearly all patients with severe reflux disease have hiatus hernia, however, a substantial proportion of patients with mild reflux disease do not, and this may be a result of intermittent or partial hiatus hernia undetectable by current available tools. The acid pocket is an area of post-prandial unbuffered gastric acidity immediately distal to the gastroesophageal junction and which is enlarged in patients with hiatus hernia. The acid pocket provides a reservoir of acid available to reflux when the intrinsic sphincter fails. Central obesity is an important factor in the aetiology of reflux and does this by the increased abdomino-thoracic pressure gradient inducing hiatus hernia and increasing the rate of flow of reflux when sphincter opens. Central obesity also induces short segment intrasphincteric reflux and thereby columnar metaplasia of the most distal oesophagus.

Acidic deoxycholic acid and chenodeoxycholic acid induce interleukin-8 production through p38 mitogen-activated protein kinase and protein kinase A in a squamous epithelial model

BACKGROUND AND AIM

Immune-mediated mucosal inflammation characterized by the production of interleukin (IL)-8 is associated with the development of gastroesophageal reflux disease. The effects of bile acids, which are major components of reflux fluid, on the production of IL-8 and related mechanisms remain unclear. This study aimed to address these questions using an esophageal stratified squamous epithelial model.

METHODS

Normal human esophageal epithelial cells were seeded on the Transwell inserts and cultured with the air-liquid interface system to establish the model. Bile acids under different pH conditions were added to the apical compartment to examine their effects on IL-8 production and the underlying cellular signaling.

RESULTS

Conjugated bile acids under a neutral or acidic condition did not induce IL-8 production, and unconjugated bile acids, deoxycholic acid (DCA), and chenodeoxycholic acid (CDCA) all significantly induced IL-8 production, dose- and time-dependently, only under weakly acid conditions. Inhibition of p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase A (PKA) attenuated the production of IL-8 induced by acidic DCA and CDCA. Inhibition of PKA did not block the bile acid-induced p38 MAPK activation.

CONCLUSIONS

Compared with conjugated bile acids, the unconjugated bile acids DCA and CDCA are more likely to induce IL-8 production in vivo, especially under weakly acid conditions. This process involves two independent signaling pathways, p38 MAPK and PKA.

The oesophagus and cough: laryngo-pharyngeal reflux, microaspiration and vagal reflexes

Gastro-oesophageal reflux disease is generally considered to be one of the commonest causes of chronic cough, however randomised controlled trials of proton pump inhibitors have often failed to support this notion. This article reviews the most recent studies investigating the mechanisms thought to link reflux and cough, namely laryngo-pharyngeal reflux, micro-aspiration and neuronal cross-organ sensitisation. How recent evidence might shed light on the failure of acid suppressing therapies and suggest new approaches to treating reflux related cough are also discussed.

Lifestyle factors associated with gastroesophageal reflux disease in the Japanese population

BACKGROUND

We aimed to clarify the lifestyle factors associated with erosive esophagitis and non-erosive reflux disease (NERD) in a Japanese population.

METHODS

Among 886 subjects who underwent health screening, we selected, according to their scores on the FSSG (frequency scale for symptoms of gastroesophageal reflux disease; GERD) questionnaire and the findings of upper gastrointestinal endoscopy, 138 subjects with erosive esophagitis (EE), 148 subjects with NERD (absence of esophagitis, FSSG score ≥8, and acid reflux-related symptoms score ≥4), and 565 control subjects (absence of esophagitis and FSSG score ≤7). We compared clinical characteristics and various lifestyle factors in these three groups.

RESULTS

The lifestyle factors significantly associated with NERD compared with findings in the control group were intake of egg (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.01-3.50), sleep shortage (OR 2.44, 95% CI 1.54-3.88), and strong psychological stress (OR 1.77, 95% CI 1.18-2.62). In male subjects, current smoking (OR 2.06, 95% CI 1.13-3.74; OR 1.87, 95% CI 1.09-3.20) was a significant risk factor for both NERD and EE. Moreover, alcohol >200 kcal/day (OR 3.99, 95% CI 1.03-15.55) and intake of a large quantity of food at supper (OR 7.85, 95% CI 1.66-37.05) were significant risk factors for EE in subjects with hiatal hernia. Intake of a large quantity of food at supper (OR 2.09, 95% CI 1.06-4.13) was more common in the NERD group than in the EE group.

CONCLUSIONS

There were differences in the associated lifestyle factors between patients with NERD and those with EE, and there was also a gender-related difference between these groups.

Effect of lateral positioning on gastroesophageal reflux (GER) and underlying mechanisms in GER disease (GERD) patients and healthy controls

BACKGROUND

Posture has been shown to influence the number of transient lower esophageal sphincter relaxation (TLESRs) and gastroesophageal reflux (GER), however, the physiology explaining the influence of right lateral position (RLP), and left lateral position (LLP) is not clear. The aim of this study was to determine the influence of RLP and LLP on TLESRs and GERD after a meal in GER disease (GERD) patients and healthy controls (HC) while monitoring gastric distension and emptying.

METHODS

Ten GERD patients and 10 HC were studied for 90 min (30 min test meal infusion, 30 min postprandial in either RLP or LLP (randomly assigned) and 30 min in alternate position). The study was repeated on a separate day in reverse position order. TLESRs, GER, and gastric emptying rate were recorded using manometry, multichannel intraluminal impedance, and (13) C-octanoate breath tests. Gastric distension was visualized by five serial gastric volume scintigraphy scans during the first 30 min.

KEY RESULTS

Gastroesophageal reflux, (GER) disease patients had increased numbers of TLESRs in RLP compared to LLP in the first postprandial hour [5 (4-14) and 4.5 (2-6), respectively, P = 0.046] whereas the number of TLESRs was not different in RLP and LLP [4 (2-4) and 4 (3-6), respectively, P = 0.7] in HC. Numbers of GER increased similar to TLESRs in GERD patients. In GERD patients, gastric emptying reached peak (13)CO(2) excretion faster and proximal gastric distension was more pronounced.

CONCLUSIONS & INFERENCES

In GERD patients, TLESRs, GER, distension of proximal stomach, and gastric emptying are increased in RLP compared to LLP. This effect is not seen in HC.

Esophageal sphincter device for gastroesophageal reflux disease

BACKGROUND

Patients with gastroesophageal reflux disease who have a partial response to proton-pump inhibitors often seek alternative therapy. We evaluated the safety and effectiveness of a new magnetic device to augment the lower esophageal sphincter.

METHODS

We prospectively assessed 100 patients with gastroesophageal reflux disease before and after sphincter augmentation. The study did not include a concurrent control group. The primary outcome measure was normalization of esophageal acid exposure or a 50% or greater reduction in exposure at 1 year. Secondary outcomes were 50% or greater improvement in quality of life related to gastroesophageal reflux disease and a 50% or greater reduction in the use of proton-pump inhibitors at 1 year. For each outcome, the prespecified definition of successful treatment was achievement of the outcome in at least 60% of the patients. The 3-year results of a 5-year study are reported.

RESULTS

The primary outcome was achieved in 64% of patients (95% confidence interval [CI], 54 to 73). For the secondary outcomes, a reduction of 50% or more in the use of proton-pump inhibitors occurred in 93% of patients, and there was improvement of 50% or more in quality-of-life scores in 92%, as compared with scores for patients assessed at baseline while they were not taking proton-pump inhibitors. The most frequent adverse event was dysphagia (in 68% of patients postoperatively, in 11% at 1 year, and in 4% at 3 years). Serious adverse events occurred in six patients, and in six patients the device was removed.

CONCLUSIONS

In this single-group evaluation of 100 patients before and after sphincter augmentation with a magnetic device, exposure to esophageal acid decreased, reflux symptoms improved, and use of proton-pump inhibitors decreased. Follow-up studies are needed to assess long-term safety. (Funded by Torax Medical; ClinicalTrials.gov number, NCT00776997.).

Symptoms of aerophagia are common in patients on continuous positive airway pressure therapy and are related to the presence of nighttime gastroesophageal reflux

STUDY OBJECTIVES

Continuous positive airway pressure (CPAP), the mainstay treatment for obstructive sleep apnea (OSA), involves administration of air under pressure to the upper airway. A well-known but poorly understood side effect of positive airway pressure therapies is aerophagia, air entering the esophagus and stomach rather than the lungs. Gastric distension, a consequence of aerophagia, can increase gastroesophageal reflux (GER) by increasing transient lower esophageal sphincter relaxations, the most common cause of reflux. This study aimed to determine: (i) the prevalence of aerophagia symptoms in a group of OSA patients on CPAP therapy, and (ii) whether aerophagia symptoms are related to an increase in prevalence of GER symptoms.

METHODS

Consecutive OSA patients undergoing polysomnography for the purpose of optimizing their CPAP therapy completed a validated questionnaire regarding GER symptoms and aerophagia symptoms. Complete datasets were collected for 259 individuals (203 males).

RESULTS

The group with aerophagia symptoms (n = 130) had a greater prevalence of frequent (≥ once a week) GER symptoms (29% vs. 10%, p < 0.05) and nighttime GER symptoms (9 vs. 2%, p < 0.05) than those without aerophagia (n = 129). The group with nighttime GER symptoms (n = 27) had a greater prevalence of aerophagia symptoms (63% vs. 23%, p < 0.05) than those without nighttime GER symptoms (n = 232).

CONCLUSIONS

In patients with OSA being treated with CPAP, the prevalence of GER and nighttime GER symptoms is greater in those with symptoms of aerophagia than those without. CPAP-induced aerophagia might precipitate GER, particularly nighttime GER, by exacerbating transient lower esophageal relaxations through gastric distension.

Sleeve gastrectomy and gastroesophageal reflux disease

Bariatric surgery, when combined with lifestyle and medical interventions, is a common and successful treatment modality in the obese patient. Laparoscopic sleeve gastrectomy is one such procedure that has increased in popularity as a definitive bariatric operation. Although laparoscopic sleeve gastrectomy has been shown to be effective in producing weight loss and improving type 2 diabetes mellitus, its effect on gastroesophageal reflux disease (GERD) has been inconsistent. This paper aims to summarize the available literature regarding GERD prevalence following laparoscopic sleeve gastrectomy, 8 studies demonstrate increased GERD prevalence, and 5 demonstrate decreased GERD prevalence following laparoscopic sleeve gastrectomy. The relationship between GERD and SG is complex and no clear relationship exists. The anatomic and physiologic changes caused by laparoscopic sleeve gastrectomy are discussed in the context of these inconsistent results.

Gastroesophageal reflux disease and atrial fibrillation: a nationwide population-based study

OBJECTIVES

Precise mechanisms of atrial fibrillation (AF) are uncertain, but their association with esophageal disorders has been recently proposed. The association between gastroesophageal reflux disease (GERD), the most common gastroesophageal disorder, and AF remains undetermined. We therefore aimed to investigate the association between GERD and later development of AF.

METHODS AND RESULTS

Patients with GERD were identified from the 1,000,000-person cohort dataset sampled from the Taiwan National Health Insurance database. The study cohort comprised 29,688 newly diagnosed adult GERD patients; 29,597 randomly selected age-, gender-, comobidity-matched subjects comprised the comparison cohort. Cox proportional hazard regressions were performed as a means of comparing the AF-free survival rate for the two cohorts. During a maximum three years of follow-up, a total of 351 patients experienced AF, including 184 (0.62%) patients in the GERD cohort and 167 (0.56%) in the control group. The log-rank test showed that patients with GERD had significantly higher incidence of AF than those without GERD (p = 0.024). After Cox proportional hazard regression model analysis, GERD was independently associated with the increased risk of AF (hazard ratio, 1.31; 95% confidence interval, 1.06-1.61, p = 0.013).

CONCLUSION

GERD was independently associated with an increased risk of future AF in a nationwide population-based cohort.

High-resolution Manometry: Esophageal Disorders Not Addressed by the "Chicago Classification"

The development of the high-resolution esophageal manometry (HRM) and the Chicago classification have improved the diagnosis and management of esophageal motility disorders. However, some conditions have yet to be addressed by this classification. This review describes findings in HRM which are not included in the current Chicago classification based on the experience in our center. This includes the analysis of the upper esophageal sphincter, proximal esophagus, longitudinal muscle contraction, disorders related to gastroesophageal reflux disease and respiratory symptoms. The utility of provocative tests and the use of HRM in the evaluation of rumination syndrome and post-surgical patients will also be discussed. We believe that characterization of the manometric findings in these areas will eventually lead to incorporation of new criteria into the existing classification.

Mechanisms of increased gastroesophageal reflux in patients with cystic fibrosis

OBJECTIVES

Up to 80% of patients with cystic fibrosis (CF) may have increased gastroesophageal reflux (GER). It has been suggested that increased GER is due to low basal lower esophageal sphincter (LES) pressure and a high number of transient LES relaxations (TLESRs). The aim of our study was to reassess the mechanisms of GER in adult CF patients using state of the art upper-gastrointestinal physiology techniques: high-resolution manometry impedance (HRM-MII).

METHODS

We studied 12 CF patients (age 32 range (19-58), 5 males/7 females) and 11 age-matched healthy volunteers (age 27 range (20-36), 4 males /7 females). HRM-MII was performed in a semi-recumbent position for 30 min during fasting and for 2 h after a standard meal (1,000 kcal). We measured total reflux and proximal extent of reflux with impedance; basal LES pressure, TLESRs, and gastroesophageal pressure gradient (GEPG) with HRM.

RESULTS

Basal LES pressure was lower in CF patients compared with healthy controls, both in the pre- and postprandial period (preprandial 13 (7-22) vs. 24 (13-26) mm Hg, P = 0.04; postprandial 10 (8-14) vs. 18 (10-31) mm Hg, P = 0.01) and TLESRs were the main mechanism for reflux both in CF and in controls. We could not find a difference in the number of TLESRs in CF patients compared with healthy (14 (10-20) vs. 13 (10-24), P = not significant). However, reflux during TLESRs was more frequent in CF compared with healthy volunteers (80 (70-95) vs. 42 (20-78) %, P = 0.0058). GEPG during TLESRs was significantly higher in CF than in controls during inspiration (13.5 (9.5-15.8) vs. 7 (4-9.9) mm Hg, P = 0.004). This difference was due to a lower inspiratory intra-thoracic pressure in CF patients (-8.2 (-10.2-(-4.6) vs. -0.08 (-5.7-2.7) mm Hg, P = 0.002). Compared with controls, CF patients had significantly higher number of reflux episodes (13 (6-20) vs. 7 (3-9), P = 0.014) and CF patients also showed a higher proportion of reflux episodes with a high proximal extent compared with healthy volunteers (49 (22-50) vs. 0 (0-17) %, P = 0.0028).

CONCLUSIONS

CF patients have increased GER with a high proximal extent. Although we could not find a higher number of TLESRs in CF, there is a higher proportion of TLESRs associated with reflux. Unlike non-CF GER disease patients (with increased intra-abdominal pressure), reflux during TLESRs in CF is probably due to an increased GEPG mainly generated by a greater inspiratory negative intra-thoracic pressure.

Pathophysiology of aerodigestive pulmonary disorders in the neonate

No test can provide a definitive diagnosis of aerodigestive disease. When interpreting tests, one should weigh the benefits and weaknesses of different technologies and methods, scientific appropriateness of the testing conditions, clinicopathologic correlation, and pharmacologic approaches. Gastroesophageal reflux disease (GERD) symptoms and airway symptoms can coexist, and they cannot be distinguished without specific testing and direct observations. Important aerodigestive disorders include dysphagia, GERD, and aggravation of airway injury due to malfunctions of swallowing or airway protection mechanisms. Objective evaluation of aerodigestive reflexes and symptom correlation may provide support for evidence-based personalized management of feeding and airway protection strategies.

Heterogeneity in oesophageal dysfunction among patients with different reflux symptoms

BACKGROUND AND AIM

Ineffective oesophageal motility (IOM) often occurs in patients with gastro-oesophageal reflux disease. We aimed to examine the hypothesis of whether the presence of IOM differs between patients with gastro-oesophageal reflux disease with different symptom profiles.

METHODS

Eligible patients were subclassified according to their predominant symptom of heartburn (HB) or acid regurgitation (AR). All patients underwent combined multichannel intraluminal impedance and oesophageal manometry. IOM was further graded according to the presence of oesophageal transit abnormalities.

RESULTS

Fourteen healthy individuals, 16 HB patients and 24 AR patients participated in this study. The percentage of swallows with complete bolus transit was lower in AR than in HB patients during liquid and viscous swallowing (P<0.05). Abnormal bolus transit occurred more frequently in AR patients than in HB patients with liquid swallows (P<0.001) and viscous swallows (P<0.05). IOM occurred more frequently in AR patients than in HB patients (42.7 vs. 12.5%, P=0.049). In patients with IOM, severe functional abnormality was more frequently found in AR patients than in HB patients (P<0.05).

CONCLUSION

This study suggests a potential link between oesophageal body dysfunction and individual reflux symptom. Patients with a predominant symptom of AR are characterized by greater IOM and defective bolus clearance.

Sedation-associated hiccups in adults undergoing gastrointestinal endoscopy and colonoscopy

AIM: To investigate whether the incidence of hiccups in patients undergoing esophagogastroduodenoscopy (EGD) or same-day bidirectional endoscopy (EGD and colonoscopy; BDE) with sedation is different from those without sedation in terms of quantity, duration and typical onset time.

METHODS: Consecutive patients scheduled for elective EGD or same-day BDE at the gastrointestinal endoscopy unit or the health examination center were allocated to two groups: EGD without sedation (Group A) and BDE with sedation (Group B). The use of sedation was based on the patients’ request. Anesthesiologists participated in this study by administrating sedative drugs as usual. A single experienced gastroenterologist performed both the EGD and the colonoscopic examinations for all the patients. The incidence, duration and onset time of hiccups were measured in both groups. In addition, the association between clinical variables and hiccups were analyzed.

RESULTS: A total of 435 patients were enrolled in the study. The incidences of hiccups in the patients with and without sedation were significantly different (20.5% and 5.1%, respectively). The use of sedation for patients undergoing endoscopy was still significantly associated with an increased risk of hiccups (adjusted odds ratio: 8.79, P < 0.001) after adjustment. The incidence of hiccups in males under sedation was high (67.4%). The sedated patients who received 2 mg midazolam developed hiccups more frequently compared to those receiving 1 mg midazolam (P = 0.0028). The patients with the diagnosis of gastroesophageal reflux disease (GERD) were prone to develop hiccups (P = 0.018).

CONCLUSION: Male patients undergoing EGD or BDE with sedation are significantly more likely to suffer from hiccups compared to those without sedation. Midazolam was significantly associated with an increased risk of hiccups. Furthermore, patients with GERD are prone to develop hiccups.

Ingestion of a carbonated beverage decreases lower esophageal sphincter pressure and increases frequency of transient lower esophageal sphincter relaxation in normal subjects

Transient lower esophageal sphincter relaxation (tLESR) and decreased basal lower esophageal sphincter (LES) pressure are postulated mechanisms of gastroesophageal reflux (GER). There is conflicting evidence on the effect of carbonated drinks on lower esophageal sphincter function. This study was conducted to assess the effect of a carbonated beverage on tLESR and LES pressure. High resolution manometry tracings (16 channel water-perfused, Trace 1.2, Hebbard, Australia) were obtained in 18 healthy volunteers (6 men) for 30 min each at baseline, and after 200 mL of chilled potable water and 200 mL of chilled carbonated cola drink (Pepsi [Pepsico India Ltd]). The sequence of administration of the drinks was determined by random number method generated by a computer. The analysis of tracings was done using TRACE 1.2 software by a physician who was unaware of the sequence of administration of fluids. The mean (SD) age of the participant was 37.3 (12.9) years. The median (range) frequency of tLESr was higher after the carbonated beverage (10.5 [0-26]) as compared to baseline (0 [0-3], p = 0.005) as well as after water (1 [0-14], p = 0.010). The LES pressure decreased after ingestion of the carbonated beverage (18.5 [11-37] mmHg) compared to baseline (40.5 [25-66] mmHg, p = 0.0001) and after water (34 [15-67] mmHg, p = 0.003). Gastric pressure was not different in the three groups. Ingestion of a carbonated beverage increases tLESr and lowers LES pressure in healthy subjects.

The effects of a novel metabotropic glutamate receptor 5 antagonist (AZD2066) on transient lower oesophageal sphincter relaxations and reflux episodes in healthy volunteers

BACKGROUND

Selective metabotropic glutamate receptor 5 (mGluR5) antagonists inhibit transient lower oesophageal sphincter relaxations (TLESRs) in animals and acid reflux in humans.

AIM

To assess the effect of single doses of the mGluR5 antagonist AZD2066 on TLESRs and reflux in humans.

METHODS

Healthy male volunteers received AZD2066 13 mg and placebo (part A), or AZD2066 2 mg and AZD2066 6 mg and placebo (part B), in a randomised crossover study. Postprandial manometry/pH-impedance measurements were taken after each dose.

RESULTS

A total of 13 individuals completed part A of the study and 19 individuals completed part B. There was a significant reduction in the geometric mean number of TLESRs (27%; P = 0.02) and the geometric mean number of reflux episodes (51%; P = 0.01) in subjects receiving AZD2066 13 mg compared with placebo. Adverse events in participants receiving AZD2066 13 mg were mostly related to the nervous system [dizziness (3/13); disturbance in attention (3/13)]. Adverse events were reversible and of mild intensity. There were no serious adverse events. The effects of AZD2066 appeared dose-dependent, with smaller reductions in TLESRs and reflux episodes (relative to placebo) and fewer adverse events observed for AZD2066 2 mg and AZD2066 6 mg compared with AZD2066 13 mg.

CONCLUSION

The mGluR5-mediated inhibition of TLESRs may be a useful approach for inhibiting gastro-oesophageal reflux.

Short-term electrical stimulation of the lower esophageal sphincter increases sphincter pressure in patients with gastroesophageal reflux disease

BACKGROUND

Electrical stimulation (ES) of the lower esophageal sphincter (LES) increases resting LES pressure (LESP) in animal models. Our aims were to evaluate the safety of such stimulation in humans, and test the hypothesis that ES increases resting LESP in patients with gastroesophageal reflux disease (GERD).

METHODS

A total of 10 subjects (nine female patients, mean age 52.6 years), with symptoms of GERD responsive to PPIs, low resting LES pressure, and abnormal 24-h intraesophageal pH test were enrolled. Those with hiatal hernia >2 cm and/or esophagitis >Los Angeles Grade B were excluded. Bipolar stitch electrodes were placed longitudinally in the LES during an elective laparoscopic cholecystectomy, secured by a clip and exteriorized through the abdominal wall. Following recovery, an external pulse generator delivered two types of stimulation for periods of 30 min: (i) low energy stimulation; pulse width of 200 μs, frequency of 20 Hz and current of 5-15 mA (current was increased up to 15 mA if LESP was less than 15 mmHg), and (ii) high energy stimulation; pulse width of 375 ms, frequency of 6 cpm, and current 5 mA. Resting LESP, amplitude of esophageal contractions and residual LESP in response to swallows were assessed before and after stimulation. Symptoms of chest pain, abdominal pain, and dysphagia were recorded before, during, and after stimulation and 7-days after stimulation. Continuous cardiac monitoring was performed during and after stimulation.

KEY RESULTS

All patients were successfully implanted nine subjects received high frequency, low energy, and four subjects received low frequency, high energy stimulation. Both types of stimulation significantly increased resting LESP: from 8.6 mmHg (95% CI 4.1-13.1) to 16.6 mmHg (95% CI 10.8-19.2), P < 0.001 with low energy stimulation and from 9.2 mmHg (95% CI 2.0-16.3) to 16.5 mmHg (95% CI 2.7-30.1), P = 0.03 with high energy stimulation. Neither type of stimulation affected the amplitude of esophageal peristalsis or residual LESP. No subject complained of dysphagia. One subject had retrosternal discomfort with stimulation at 15 mA that was not experienced with stimulation at 13 mA. There were no adverse events or any cardiac rhythm abnormalities with either type of stimulation.

CONCLUSIONS & INFERENCES

Short-term stimulation of the LES in patients with GERD significantly increases resting LESP without affecting esophageal peristalsis or LES relaxation. Electrical stimulation of the LES may offer a novel therapy for patients with GERD.

Localization of mGluR5, GABAB, GABAA, and cannabinoid receptors on the vago-vagal reflex pathway responsible for transient lower esophageal sphincter relaxation in humans: an immunohistochemical study

BACKGROUND

  Transient lower esophageal sphincter relaxations (TLESRs) are the predominant mechanisms underlying gastro-esophageal reflux. TLESRs are mediated by a vago-vagal reflex, which can be blocked by interaction with metabotropic Glutamate Receptor 5 (mGluR5), γ-aminobutyric acid type B (GABA(B)), γ-aminobutyric acid type A (GABA(A)), and cannabinoid (CB) receptors. However, the distribution of these receptors in the neural pathway underlying the triggering of TLESRs has not been evaluated in humans.

METHODS

  Using immunohistochemistry, we investigated the distribution of mGluR5, GABA(A), GABA(B), CB1, and CB2 receptors in the human nodose ganglion, the brain stem, and the myenteric plexus of the esophagus.

KEY RESULTS

  MGluR5, GABA(B), CB1, and CB2 receptors are abundantly expressed in neurons of the myenteric plexus of the LES, nodose ganglion cell bodies and nerve fibers, the dorsal motor nucleus, and nucleus of the solitary tract in the brain stem. GABA(A) receptors are expressed in the same regions except in the nodose ganglion and myenteric plexus of the LES.

CONCLUSIONS & INFERENCES

  Human mGluR5, GABA(A,B), and CB(1,2) receptors are abundantly expressed along the vago-vagal neural pathway and involved in the triggering of TLESRs. These findings are not only in line with the central side effects observed during treatment with reflux inhibitors such as GABA(B) receptor agonists and mGluR5 antagonists, but also suggest that peripherally acting compounds may be effective.

Gastroesophageal reflux disease in children and adolescents: when and how to treat

Gastroesophageal reflux (GER) is a common presenting complaint in children and adults, and is a frequent reason for physician consultation. GER disease (GERD), whilst benign in the majority of cases, is frequently a chronic condition that has been shown to result in significantly reduced quality of life in children and adolescents. Furthermore, there is emerging evidence that the prevalence of GERD is rising and may have links to adult obesity and other morbidities. Consequently, accurate diagnosis, appropriate management strategies, and timely referral to specialist services are important principles in the effective management of GERD. Acid-suppressive drugs are effective therapies but are one of the most costly classes of drugs prescribed. Therefore, not only is an accurate diagnosis important to the patient, but it is also of significant interest from a public health and resource utilization standpoint.

Comparisons of symptoms reported by elderly and non-elderly patients with GERD

BACKGROUND

The characteristics of symptoms reported by elderly patients with gastroesophageal reflux disease (GERD) have not been fully investigated. We performed this study to clarify these characteristics in elderly patients with GERD.

METHODS

The study subjects were 340 Japanese patients with symptoms of heartburn and/or acid regurgitation. All patients were investigated by upper gastrointestinal endoscopy, and were asked about the presence of atypical GERD symptoms, such as an epigastric burning sensation, epigastralgia, epigastric discomfort, and abdominal fullness, as well as the time of day when bothersome symptoms occurred.

RESULTS

Of the 340 patients, 161 were elderly (≥65 years old) and 179 were non-elderly (age <65 years). There were 158 patients without esophageal mucosal breaks, 147 with low-grade reflux esophagitis (RE; Los Angeles classification grade A or B), and 35 with high-grade reflux esophagitis (LA grade C or D). Elderly patients with RE reported typical reflux symptoms at the same frequency as the non-elderly patients, whereas elderly patients without mucosal breaks reported typical symptoms more frequently than the non-elderly patients without mucosal breaks. Both elderly and non-elderly patients with different types of GERD reported that their symptoms occurred most frequently during the postprandial period.

CONCLUSION

Elderly patients with GERD tend to show typical GERD symptoms frequently at the typical post-prandial time points in a day, irrespective of the presence of esophageal mucosal breaks.

Mechanisms of reflux perception in gastroesophageal reflux disease: a review

Patients with reflux symptoms often do not have excessive esophageal acid exposure, and patients with severe gastroesophageal reflux often do not have reflux symptoms. Understanding why different types of reflux induce symptoms in different patients is vital for addressing therapeutic gaps in the treatment of gastroesophageal reflux disease (GERD). Here we review studies providing insight into how gastroesophageal reflux is perceived, with a focus on comparing reflux characteristics and esophageal sensitivity among subgroups of patients with GERD. The available studies indicate that patients with nonerosive reflux disease have fewer acid reflux episodes and thus less esophageal acid exposure than patients with reflux esophagitis but perceive less intense stimuli because of greater esophageal sensitivity. Reflux characteristics other than acidity, such as the presence of bile, pepsin, liquid, or gas in reflux, and the proximal extent or volume of reflux, may also contribute to symptom perception. Factors contributing to greater esophageal sensitivity may include impaired mucosal barrier function, peripherally mediated esophageal sensitivity (enhanced esophageal receptor signaling), and centrally mediated esophageal sensitivity (physiological stressors, sensitization of spinal sensory neurons). Further insight into mechanisms of reflux perception may require a shift toward studies aimed at understanding predisposing cellular, molecular, and genetic factors.

Objective definition and detection of transient lower esophageal sphincter relaxation revisited: is there room for improvement?

BACKGROUND

The advent of drugs that inhibit transient lower esophageal sphincter relaxation (TLESR) necessitates accurate identification and scoring. We assessed the intra- and inter-assessor variability of the existing objective criteria for TLESR, improving them where necessary.

METHODS

Two 3-h postprandial esophageal manometric and pH recordings were performed in 20 healthy volunteers. Each recording was duplicated. The recordings were analyzed by five experienced observers for TLESRs based on their expert opinion. TLESRs were also analyzed for the presence of the original four criteria as well as inhibition of the crural diaphragm (ID), a prominent after-contraction (AC), acid reflux and an esophageal common cavity.

KEY RESULTS

The overall inter- and intra-observer agreements for TLESRs scored, according to observer's expert opinion, were 59% (range 56-67%) and 74% (60-89%), respectively. When TLESRs were restricted to those fulfilling the original criteria, these agreements fell to 46% (40-53%) and 60% (44-67%), respectively. Cleaning the recordings by removal of technically flawed sections improved agreements by 5%. Inclusion of additional criteria (ID and AC) resulted in inter- and intra-observer agreements of 62% (52-70%) and 69% (53-79%), respectively. A consensus analysis performed collectively by three observers and based on the new criteria (original ± ID and AC) resulted in 84% agreement between the paired recordings.

CONCLUSIONS & INFERENCES

The original criteria for the definition of TLESRs allows for substantial inter- and intra-observer variability, which can be reduced by incorporation of additional objective criteria. However, the highest level of intra-observer agreement can be achieved by consensus analysis.

Gastroesophageal reflux disease and tooth erosion

The increasing prevalence of gastroesophageal reflux disease (GERD) in children and adults, and of “silent refluxers” in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may result in many esophageal and extraesophageal adverse conditions. Sleep-related GERD is particularly insidious as the supine position enhances the proximal migration of gastric contents, and normal saliva production is much reduced. Gastric acid will displace saliva easily from tooth surfaces, and proteolytic pepsin will remove protective dental pellicle. Though increasing evidence of associations between GERD and tooth erosion has been shown in both animal and human studies, relatively few clinical studies have been carried out under controlled trial conditions. Suspicion of an endogenous source of acid being associated with observed tooth erosion requires medical referral and management of the patient as the primary method for its prevention and control.

Transient lower esophageal sphincter relaxation pharmacokinetic-pharmacodynamic modeling: count model and repeated time-to-event model

Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism for gastroesophageal reflux. Characterizations of candidate compounds for reduction of TLESRs are traditionally done through summary exposure and response measures and would benefit from model-based analyses of exposure-TLESR events relationships. Pharmacokinetic (PK)-pharmacodynamic (PD) modeling approaches treating TLESRs either as count data or repeated time-to-event (RTTE) data were developed and compared in terms of their ability to characterize system and drug characteristics. Vehicle data comprising 294 TLESR events were collected from nine dogs. Compound [(R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate (WIN55212-2)] data containing 66 TLESR events, as well as plasma concentrations, were obtained from four dogs. Each experiment lasted for 45 min and was initiated with a meal. Counts in equispaced 5- and 1-min intervals were modeled based on a Poisson probability distribution model. TLESR events were analyzed with the RTTE model. The PK was connected to the PD with a one-compartment model. Vehicle data were described by a baseline and a surge function; the surge peak was determined to be approximately 9.69 min by all approaches, and its width in time at half-maximal intensity was 5 min (1-min count and RTTE) or 10 min (5-min count). TLESR inhibition by WIN55212-2 was described by an I(max) model, with an IC(50) of on average 2.39 nmol · l(-1). Modeling approaches using count or RTTE data linked to a dynamic PK-PD representation of exposure are superior to using summary PK and PD measures and are associated with a higher power for detecting a statistically significant drug effect.

New pharmacologic approaches in gastroesophageal reflux disease

This article highlights current and emerging pharmacological treatments for gastroesophageal reflux disease (GERD), opportunities for improving medical treatment, the extent to which improvements may be achieved with current therapy, and where new therapies may be required. These issues are discussed in the context of current thinking on the pathogenesis of GERD and its various manifestations and on the pharmacologic basis of current treatments.

Distension of the esophagogastric junction augments triggering of transient lower esophageal sphincter relaxation

Patients with gastroesophageal reflux disease show an increase in esophagogastric junction (EGJ) distensibility and in frequency of transient lower esophageal sphincter relaxations (TLESR) induced by gastric distension. The objective was to study the effect of localized EGJ distension on triggering of TLESR in healthy volunteers. An esophageal manometric catheter incorporating an 8-cm internal balloon adjacent to a sleeve sensor was developed to enable continuous recording of EGJ pressure during distension of the EGJ. Inflation of the balloon doubled the cross-section of the trans-sphincteric portion of the catheter from 5 mm OD (round) to 5 × 11 mm (oval). Ten healthy subjects were included. After catheter placement and a 30-min adaptation period, the EGJ was randomly distended or not, followed by a 45-min baseline recording. Subjects consumed a refluxogenic meal, and recordings were made for 3 h postprandially. A repeat study was performed on another day with EGJ distension status reversed. Additionally, in one subject MRI was performed to establish the exact position of the balloon in the inflated state. The number of TLESR increased during periods of EGJ distension with the effect being greater after a meal [baseline: 2.0(0.0-4.0) vs. 4.0(1.0-11.0), P=0.04; postprandial: 15.5(10.0-33.0) vs. 22.0(17.0-58.0), P=0.007 for undistended and distended, respectively]. EGJ distension augments meal-induced triggering of TLESR in healthy volunteers. Our data suggest the existence of a population of vagal afferents located at sites in/around the EGJ that may influence triggering of TLESR.