Proximal migration of esophageal acid perfusions during waking and sleep

Nocturnal gastro-oesophageal reflux and respiratory symptoms are increased in sleep apnoea: comparison with the general population

AIM

To assess respiratory symptoms and nocturnal gastro-oesophageal reflux (nGER) among untreated obstructive sleep apnoea (OSA) patients, compared with the general population. Also, if nGER associates differently with respiratory symptoms among OSA patients.

METHODS

2 study cohorts were included: 822 newly diagnosed subjects with moderate-severe OSA and 738 Icelandic general population study participants. All participants answered the same questionnaires. Those reporting nGER symptoms at least once per week were defined as 'with nGER'; those without nGER symptoms and without nGER medication were defined as 'no nGER'; and other participants were defined as having 'possible nGER'. Propensity score-based weights were used to minimise confounding and selection bias and facilitate causal interpretations.

RESULTS

The prevalence of nGER among OSA patients was 14.1%, compared with 5.8% in the general population. This increased prevalence in OSA was not explained by differences in age, gender, body mass index, smoking, hypertension and diabetes (adjusted OR (95% CI)=3.79 (2.24 to 6.43)). OSA patients 'with nGER' and with 'possible nGER' reported more wheezing (44% and 44% vs 25%, respectively) and productive cough (47% and 42% vs 29%, respectively), compared with OSA patients with 'no nGER'. The same pattern was seen in the general population, although with a generally lower prevalence. The effect of nGER on respiratory symptoms was similar between the two cohorts.

CONCLUSION

nGER was more often reported among untreated moderate-severe OSA patients than in the general population. Participants with nGER had more wheezing and productive cough, both among untreated OSA patients and in the general population.

Interrelationship Between Obstructive Sleep Apnea Syndrome and Severe Asthma: From Endo-Phenotype to Clinical Aspects

Sleep-related breathing disorders (SBDs) are characterized by abnormal respiration during sleep. Obstructive sleep apnea (OSA), a common SBD increasingly recognized by physicians, is characterized by recurrent episodes of partial or complete closure of the upper airway resulting in disturbed breathing during sleep. OSA syndrome (OSAS) is associated with decreased patients' quality of life (QoL) and the presence of significant comorbidities, such as daytime sleepiness. Similarly to what seen for OSAS, the prevalence of asthma has been steadily rising in recent years. Interestingly, severe asthma (SA) patients are also affected by poor sleep quality—often attributed to nocturnal worsening of their asthma—and increased daytime sleepiness and snoring compared to the general population. The fact that such symptoms are also found in OSAS, and that these two conditions share common risk factors, such as obesity, rhinitis, and gastroesophageal reflux, has led many to postulate an association between these two conditions. Specifically, it has been proposed a bidirectional correlation between SA and OSAS, with a mutual negative effect in term of disease severity. According to this model, OSAS not only acts as an independent risk factor of asthma exacerbations, but its co-existence can also worsen asthma symptoms, and the same is true for asthma with respect to OSAS. In this comprehensive review, we summarize past and present studies on the interrelationship between OSAS and SA, from endo-phenotype to clinical aspects, highlighting possible implications for clinical practice and future research directions.

Association between body positioning and gastroesophageal reflux in paediatric age

AIM

Postural measures are frequently recommended for gastroesophageal reflux (GER) symptoms, despite limited evidence. This was the first study to assess the impact of upright and recumbent body positions on GER episodes in children and adolescents, not just infants.

METHODS

We retrospectively assessed the pH-impedance parameters of paediatric patients referred for possible GER-related symptoms to two hospitals in Naples and Rome, Italy, from September 2016 to September 2018. Data were separately obtained for the time that the patients spent in upright and recumbent positions.

RESULTS

Data from 187 patients under the age of 18 were collected, at a mean age of just over seven years. We found that the acid exposure time was stable irrespective of changes in body position (P > .05). The mean number of reflux episodes per hour was 2.99 during the upright position and 1.21 during the recumbent position (P < .05), and the mean oesophageal acid clearance time was 44.4 and 93.4 seconds, respectively (P < .05).

CONCLUSION

Most paediatric patients experienced reflux in the upright rather than recumbent position, probably as a result of frequent transient lower oesophageal sphincter relaxations while they were awake. In particular, our findings provide new insights into postural measures for reflux in children and adolescents.

The Effects of Sleep on the Commensal Microbiota: Eyes Wide Open?

Sleep dysfunction is an epidemic, the implications of which have a profound impact on a variety of gastrointestinal disease. Recent data suggests a relationship between sleep dysfunction and intestinal dysbiosis, a known proinflammatory driver. This article evaluates the interplay between sleep dysfunction and gastrointestinal health and disease, with a focus on the impact of circadian rhythm disruption on the commensal microbiota.

Wake-up Call to Clinicians: The Impact of Sleep Dysfunction on Gastrointestinal Health and Disease

Sleep dysfunction is an epidemic affecting a large portion of the adult population. Recent studies have linked sleep dysfunction with an upregulation of proinflammatory cytokines (eg, tumor necrosis factor-α, interleukin-1 and interleukin-6), the implications of which can have a profound impact on a variety of gastrointestinal disease. In particular, sleep dysfunction seems to accelerate disease states characterized by inflammation (eg, gastroesophageal reflux disease, irritable bowel syndrome and functional dyspepsia, chronic liver disease, inflammatory bowel disease, and colorectal cancer). This article evaluates the complex interplay between sleep dysfunction and gastrointestinal health and disease.

Definition of nocturnal gastroesophageal reflux for studies on respiratory diseases

OBJECTIVE

Nocturnal gastroesophageal reflux (nGER) has been associated with respiratory diseases. Our aim was to study a questionnaire method to identify nGER subjects with respiratory involvement in a general population.

MATERIAL AND METHODS

A subgroup of Icelandic participants in the European Community Respiratory Health Survey III (ECRHS III) reporting symptoms of nGER (n  =  48) as well as age and gender paired controls (n  =  42) were studied further by a structured interview, questionnaires, laryngeal fibrescopy, and exhaled breath condensate. A subgroup underwent 24-h oesophageal pH impedance (24-h MII-pH) measurements. Symptoms of nGER were assessed with a modified version of the reflux disease questionnaire (RDQ), where symptoms were divided into daytime and nocturnal. A report of nGER both at baseline and at follow-up was defined as persistent nGER.

RESULTS

Participants reporting persistent nGER had significantly more signs of laryngopharyngeal reflux according to the reflux finding score than those without nGER (Mean ± SD: 5.1 ± 2.3 vs. 3.9 ± 2.2, p  =  0.02). Of the 16 persistent nGER subjects that underwent 24-h MII-pH, 11 had abnormal gastroesophageal reflux, but none of three control subjects (69% vs. 0%). Pepsin was more commonly found in exhaled breath condensate in the nGER group (67% vs. 45%, p  =  0.04).

CONCLUSIONS

Participants with nGER symptoms at least once a month, reported on two occasions, had a high level of positive 24-h MII-pH measurements, laryngeal inflammation and pepsin in exhaled breath condensate. This nGER definition identified a representable group for studies on nGER and respiratory diseases in a general population.

Gastroesophageal reflux disease in COPD: links and risks

COPD is a long-term condition associated with considerable disability with a clinical course characterized by episodes of worsening respiratory signs and symptoms associated with exacerbations. Gastroesophageal reflux disease (GERD) is one of the most common gastrointestinal conditions in the general population and has emerged as a comorbidity of COPD. GERD may be diagnosed by both symptomatic approaches (including both typical and atypical symptoms) and objective measurements. Based on a mix of diagnostic approaches, the prevalence of GERD in COPD ranges from 17% to 78%. Although GERD is usually confined to the lower esophagus in some individuals, it may be associated with pulmonary microaspiration of gastric contents. Possible mechanisms that may contribute to GERD in COPD originate from gastroesophageal dysfunction, including altered pressure in the lower esophageal sphincter (which normally protect against GERD) and changes in esophageal motility. Proposed respiratory contributions to the development of GERD include respiratory medications that may alter esophageal sphincter tone and changes in respiratory mechanics, with increased lung hyperinflation compromising the antireflux barrier. Although the specific cause and effect relationship between GERD and COPD has not been fully elucidated, GERD may influence lung disease severity and has been identified as a significant predictor of acute exacerbations of COPD. Further clinical effects could include a poorer health-related quality of life and an increased cost in health care, although these factors require further clarification. There are both medical and surgical options available for the treatment of GERD in COPD and while extensive studies in this population have not been undertaken, this comorbidity may be amenable to treatment.

Association between asthma and risk of developing obstructive sleep apnea

IMPORTANCE

Obstructive sleep apnea (OSA) is more common among patients with asthma; whether asthma is associated with the development of OSA is unknown.

OBJECTIVE

To examine the prospective relationship of asthma with incident OSA.

DESIGN, SETTING, AND PARTICIPANTS

Population-based prospective epidemiologic study (the Wisconsin Sleep Cohort Study) beginning in 1988. Adult participants were recruited from a random sample of Wisconsin state employees to attend overnight polysomnography studies at 4-year intervals. Asthma and covariate information were assessed during polysomnography studies through March 2013. Eligible participants were identified as free of OSA (apnea-hypopnea index [AHI] of <5 events/h and not treated) by 2 baseline polysomnography studies. There were 1105 4-year follow-up intervals provided by 547 participants (52% women; mean [SD] baseline age, 50 [8] years).

EXPOSURES

Questionnaire-assessed presence and duration of self-reported physician-diagnosed asthma.

MAIN OUTCOMES AND MEASURES

The associations of presence and duration of asthma with 4-year incidences of both OSA (AHI of ≥5 or positive airway pressure treatment) and OSA concomitant with habitual daytime sleepiness were estimated using repeated-measures Poisson regression, adjusting for confounders.

RESULTS

Twenty-two of 81 participants (27% [95% CI, 17%-37%]) with asthma experienced incident OSA over their first observed 4-year follow-up interval compared with 75 of 466 participants (16% [95% CI, 13%-19%]) without asthma. Using all 4-year intervals, participants with asthma experienced 45 cases of incident OSA during 167 4-year intervals (27% [95% CI, 20%-34%]) and participants without asthma experienced 160 cases of incident OSA during 938 4-year intervals (17% [95% CI, 15%-19%]); the corresponding adjusted relative risk (RR) was 1.39 (95% CI, 1.06-1.82), controlling for sex, age, baseline and change in body mass index, and other factors. Asthma was also associated with new-onset OSA with habitual sleepiness (RR, 2.72 [95% CI, 1.26-5.89], P = .045). Asthma duration was related to both incident OSA (RR, 1.07 per 5-year increment in asthma duration [95% CI, 1.02-1.13], P = .01) and incident OSA with habitual sleepiness (RR, 1.18 [95% CI, 1.07-1.31], P = .02).

CONCLUSIONS AND RELEVANCE

Asthma was associated with an increased risk of new-onset OSA. Studies investigating the mechanisms underlying this association and the value of periodic OSA evaluation in patients with asthma are warranted.

Physiology of sleep and breathing before and after lung transplantation

During the past 20 years, lung transplantation (LTX) has evolved and it is now accepted as a mainstream modality for care of patients with severe life-threatening respiratory diseases that are refractory to maximal conventional therapies. Improvements in surgical techniques and in antirejection medications have resulted in prolonged survival in these patients. Several studies have explored quality of life after LTX and its improvement has been noted especially in the early period between 3 and 6 months. This article discusses the salient features of the physiology of breathing and sleep disturbances before and after LTX and its alterations during sleep.

Integrating the overlap of obstructive lung disease and obstructive sleep apnoea: OLDOSA syndrome

Obstructive lung diseases (OLD) such as asthma and chronic obstructive pulmonary disease (COPD) are very prevalent conditions. Disease phenotypes (e.g. chronic bronchitis, emphysema, etc.) often overlap, and significant confusion exists about their optimal nosologic characterization. Obstructive sleep apnoea (OSA) is also a common condition that features bidirectional interactions with OLD. OSA appears to be more commonly seen in patients with OLD, perhaps as a result of shared risk factors, for example obesity, smoking, increased airway resistance, local and systemic inflammation, anti-inflammatory therapy. Conversely, OSA is associated with worse clinical outcomes in patients with OLD, and continuous positive airway pressure therapy has potential beneficial effects on this vicious pathophysiological interaction. Possible shared mechanistic links include increased parasympathetic tone, hypoxaemia-related reflex bronchoconstriction/vasoconstriction, irritation of upper airway neural receptors, altered nocturnal neurohormonal secretion, pro-inflammatory mediators, within and inter-breath interactions between upper and lower airways, lung volume-airway dependence, etc. While the term overlap syndrome has been defined as the comorbid association of COPD and OSA, the interaction between asthma and OSA has not been integrated yet nosologically; in this review, the latter will be called alternative overlap syndrome. In an effort to bolster further investigations in this area, an integrated, lumping nomenclature for OSA in the setting of OLD is proposed here--OLDOSA (obstructive lung disease and obstructive sleep apnoea) syndrome.

Gastrointestinal physiology and digestive disorders in sleep

PURPOSE OF REVIEW

The dynamic interplay of the digestive system and sleep is an excellent example of brain-body interaction. New advances in measuring techniques provide an opportunity to evaluate physiology that is dependent upon the sleep/wake state or circadian rhythm and potentially differentiate between normal and pathological conditions.

RECENT FINDINGS

Sleep-related changes in gastrointestinal physiology create vulnerabilities to digestive issues such as reflux, whereas disorders such as duodenal ulcers raise the importance of circadian variations in digestive system function. Advances in the area of normal sleep physiology have furthered our understanding of the underlying cause of irritable bowel syndrome, and the mechanisms by which sleep disruption may aggravate inflammatory bowel disease. Additionally, important early work has shown that the treatment of digestive disorders such as reflux can improve sleep quality just as the improvement in sleep may aid in the treatment of digestive disorders.

SUMMARY

For the clinician, these forward steps in our knowledge mark the start of an era in which understanding the effects of the sleep/wake state and circadian rhythms on gastrointestinal physiology promise to yield novel diagnostic and therapeutic opportunities.

Advancements in the analysis of esophageal pH monitoring in GERD

Ambulatory 24 h esophageal pH monitoring enables quantification of esophageal acid exposure and assessment of the temporal relationship between symptoms and acid reflux events. Analysis of pH monitoring is currently divided into upright and recumbent periods based on the patient's body position. However, in this Review, we demonstrate that physiologic studies have shown that sleep, and not recumbency, has a greater impact on gastroesophageal reflux during night-time. The physiologic studies are further supported by clinical trials demonstrating that gastroesophageal reflux characteristics during the recumbent-awake period are similar to those in the upright rather than the recumbent-asleep period. The introduction of the integrated pH monitoring and actigraphy data analysis program offers better separation of the recumbent-awake and recumbent-asleep periods. The physiologic studies and clinical trials, as well as the availability of a better tool to measure pH during sleep, support a paradigm shift in the analysis of pH monitoring data from body position (upright or recumbent) to state of consciousness (awake or asleep).

Influence of experimental esophageal acidification on sleep bruxism: a randomized trial

The aim of this cross-over, randomized, single-blinded trial was to examine whether intra-esophageal acidification induces sleep bruxism (SB). Polysomnography with electromyogram (EMG) of masseter muscle, audio-video recording, and esophageal pH monitoring were performed in a sleep laboratory. Twelve healthy adult males without SB participated. Intra-esophageal infusions of 5-mL acidic solution (0.1 N HCl) or saline were administered. The frequencies of EMG bursts, rhythmic masticatory muscle activity (RMMA) episodes, grinding noise, and the RMMA/microarousal ratio were significantly higher in the 20-minute period after acidic infusion than after saline infusion. RMMA episodes including SB were induced by esophageal acidification. This trial is registered with the UMIN Clinical Trials Registry, UMIN000002923.

ABBREVIATIONS

ASDA, American Sleep Disorders Association; EMG, electromyogram; GER, gastroesophageal reflux; LES, lower esophageal sphincter; NREM, non-rapid eye movement; REM, rapid eye movement; RMMA, rhythmic masticatory muscle activity; SB, sleep bruxism; SD, standard deviation; UES, upper esophageal sphincter.

The refluxate: The impact of its magnitude, composition and distribution

The pathogenesis of gastrointestinal reflux disease is multifactoral. Integral to the disease process is the refluxate itself. The characteristics and composition of the refluxate are dependent on several physiological variables. The refluxate may contain varying concentrations of acid, pepsin, gas, or contents of duodenal reflux (such as bile acid and pancreatic enzymes). Characteristics such as volume and proximal extent of the refluxate, and the chemical content of this refluxate can strongly influence the risk of symptom perception. Strong acid (pH<4) and duodeno-gastro-oesophageal reflux are also implicated in the development of mucosal damage in the form of oesophagitis, Barrett's metaplasia and oesophageal adenocarcinoma. The manifestation of disease, however, is not entirely reliant on the refluxate, which must be considered in the context of the genetic, environmental and psychological susceptibility of the individual.

[Bronchopulmonary manifestations of gastroesophageal reflux disease]

Gastroesophageal reflux disease (GERD) is a common disease in the western world. Usually it occurs with typical symptoms like heartburn and regurgitation, but almost every third GERD-patient presents with extraesophageal symptoms and diseases in which a causal relation with GERD is discussed. The extraesophageal symptoms possibly associated with GERD are chronic cough, bronchial asthma, sleep disturbances including obstructive sleep apnea, hoarseness, dental erosions, non-cardiac chest pain and idiopathic pulmonary fibrosis. This article gives an overview of the reflux-associated diseases of the airways as well as the proposed pathomechanisms and therapeutic options.

Reassessment of the principal characteristics of gastroesophageal reflux during the recumbent period using integrated actigraphy-acquired information

OBJECTIVES

Characterization of gastroesophageal reflux (GERD) events during the sleep period has been hampered by lack of any patient-friendly technique that allows accurate assessment of sleep duration and awakening time, without confining patients to a sleep laboratory. Our aim was to compare principal reflux characteristics during the upright, recumbent-awake, and recumbent-asleep periods as well as to determine the effect of sleep awakenings on the principal reflux characteristics of the recumbent-asleep period using novel technology that allows integration of recorded actigraphy data into collected pH information.

METHODS

Patients with heartburn at least three times a week for the previous 3 months were invited to participate in this study. All participants were evaluated by the demographics and the GERD Symptom Checklist questionnaires. Thereafter, patients underwent ambulatory 24-h esophageal pH monitoring concomitantly with actigraphy. A novel technique was used to superimpose simultaneously recorded raw actigraphy data over pH data, resulting in more accurate information about reflux events during upright, recumbent-awake, recumbent-asleep, and conscious awakening periods as well as the relationship between symptoms and acid reflux events in the aforementioned periods.

RESULTS

Thirty-nine subjects (M/F: 26/13, mean age 56.6+/-14 years) with an abnormal pH test were enrolled into the study. The recumbent period appeared heterogeneous and was clearly divided into recumbent-awake (123.0+/-20.2 min) and recumbent-asleep (485.6+/-23.6 min) periods. The percent total time pH<4, the mean number of acid reflux events, and the number of symptoms associated with reflux events were significantly greater in the recumbent-awake as compared with the recumbent-asleep period. The mean duration of an acid reflux event was not different among upright, recumbent-awake, and recumbent-asleep periods. However, short-duration reflux events during the sleep period were associated with conscious awakenings as compared with those during sleep (0.74+/-0.11 min vs. 1.64+/-0.3 min, P=0.01).

CONCLUSIONS

The recumbent period is divided into recumbent-awake and recumbent-asleep periods. The recumbent-awake period has significantly different principal reflux characteristics than the recumbent-asleep period. Duration of an acid reflux event during the recumbent-asleep period is not uniformly prolonged. Short-duration acid reflux events during the sleep period are likely due to conscious awakenings.

Review article: sleep-related gastro-oesophageal reflux as a distinct clinical entity

BACKGROUND

Many patients with chronic gastro-oesophageal reflux disease (GERD) have frequent nighttime heartburn as well as sleep-related gastro-oesophageal reflux (GOR). Sleep-related GOR has been shown to play an important role in the development of oesophagitis and other complications of GOR.

AIM

To present a conceptual argument that nighttime heartburn and associated sleep-related GOR should be recognized as a distinct clinical entity deserving special attention with regard to the diagnosis and treatment of GERD.

METHODS

The data presented come from surveys of GERD patients as well as from physiological studies to include studies monitoring oesophageal pH and spontaneous reflux events during polysomnographically (PSG) monitored sleep.

RESULTS

Evidence is presented to show that nighttime heartburn is prevalent and its occurrence separates patients from those who have heartburn most exclusively in the daytime. The evidence presented also supports the notion that nighttime heartburn sufferers have a more complicated disease and they have a greater risk of developing oesophagitis and other respiratory complications. The data also show that responses to acid mucosal contact are quite different during sleep compared to responses measured during the waking state.

CONCLUSIONS

Nighttime heartburn and GOR represent a distinct clinical entity which deserves specific attention in the diagnosis and optimal treatment of GERD.

Effect of zolpidem on the sleep arousal response to nocturnal esophageal acid exposure

BACKGROUND & AIMS

Nocturnal acid reflux is associated with complicated gastroesophageal reflux (GER) disease. Nocturnal GER initiates a protective arousal reflex, which induces a swallow to clear esophageal acid. The purpose of this study was to determine the effect of zolpidem on the sleep arousal mechanism and acid clearance in patients with documented GER, compared with control subjects with normal acid exposure.

METHODS

Eight controls and 16 GER patients were enrolled in a randomized, double-blind, placebo-controlled study. Zolpidem or placebo was given on separate nights. Reflux events and reflux-associated arousals or awakenings were recorded using simultaneous esophageal pH recording and standard polysomnography.

RESULTS

Nocturnal acid exposure resulted in a sleep arousal 89% of the time in participants (with and without GER) given placebo but only 40% in those given zolpidem (P < .01). In controls given placebo, acid reflux events lasted 1.15 +/- 0.28 seconds; in controls given zolpidem, they lasted 15.67 +/- 12.42 seconds (P < .01). In GER patients given placebo, the acid reflux events lasted 37.8 +/- 17.2 seconds compared with 363.3 +/- 139.3 seconds with zolpidem (P < .01). With zolpidem reflux events lasted 630.6 +/- 236.5 seconds when no arousal occurred and 49.2 +/- 19.11 seconds when an arousal was recorded (P < .001).

CONCLUSIONS

Zolpidem reduced the arousal response to nocturnal acid exposure and increased the duration of each esophageal acid reflux event in healthy individuals and patients with GER. Because nocturnal acid exposure was prolonged, hypnotic use by patients with GER could lead to increased risk for complicated disease.

Proximal oesophagus: the added value in understanding GORD symptoms

Over the past decade, the approach to the understanding of the mechanisms involved in the aetiology of gastro-oesophageal reflux disease (GORD) symptoms has changed, and growing evidence now supports the concept that visceral hyper-sensitivity to intra-oesophageal stimuli plays a major role. Among the recent advances, one of the more consistent findings is that the contact of the refluxate, either acidic or weakly acidic, with the proximal oesophageal mucosa, is a main determinant of GORD symptoms, particularly in the large majority of patients affected by non-erosive reflux disease. The data reported in the current issue of Neurogastroenterology and Motility by Bredenoord et al., showing only a small proportion of proximal reflux in patients with Barrett's oesophagus, who are less sensitive to gastro-oesophageal reflux, further support the consistency of this finding in the pathogenesis of symptoms. In the light of these results, we shall look forward, in the management of patients, to approaches aimed at restoring the antireflux barrier, hopefully decreasing the amount of reflux and, in turn, its proximal extent.

A systematic review of the definitions, prevalence, and response to treatment of nocturnal gastroesophageal reflux disease

BACKGROUND & AIMS

More than half of patients with chronic gastroesophageal reflux (GERD) report nocturnal symptoms. We performed systematic literature review to define nocturnal heartburn and to determine potential causality between nocturnal reflux and extraesophageal manifestations.

METHODS

We performed a search of literature published from 1974-2007. Each study was examined by 2 reviewers and rated on the basis of study type and outcome.

RESULTS

Screening of 445 trials identified 59 (13%) studies relevant for analysis. Twenty-two (5%) of the trials described potential changes in sleep parameters resulting from treatment of heartburn. In most studies, nocturnal reflux was defined as heartburn symptoms that impacted sleep quality and duration. On the basis of 5 large population studies, the mean +/- standard deviation prevalence of nocturnal heartburn was 54% +/- 22%. Consequences of nocturnal reflux included poor sleep quality, daytime fatigue, difficulty initiating sleep or arousals from sleep, and impaired work productivity. The strength of the association between the occurrence of nocturnal reflux and late evening meals was flawed as a result of the confounding effect of the evening meal content. There was no evidence supporting causality between nocturnal heartburn and asthma or obstructive sleep apnea. Subjective, but not objective, measures of sleep improved with antireflux therapy. Head of bed elevation, proton pump inhibitor therapy, H(2)-receptor antagonists, and Nissen fundoplication alleviated nocturnal heartburn and associated sleep disturbances.

CONCLUSIONS

Nocturnal GERD is common and is associated with adverse sleep parameters. It can be effectively managed with medical and surgical therapy.

Analysis of 24-hour esophageal pH monitoring: the effect of state of consciousness

This review addresses current advances in the diagnosis of sleep-related gastroesophageal reflux using ambulatory esophageal pH monitoring and laboratory monitoring, which includes polygraphic assessment of the state of consciousness. This 24-hour pH monitoring uses a new strategy of interpretation that characterizes acidic reflux events and specifically assesses the patient's position and state of consciousness. Thus, the recognition of reflux events during waking and sleep will add to the overall assessment of gastroesophageal reflux and its severity and clinical relevance. The pH testing, together with overnight polysomnography, offers an opportunity to link nighttime reflux with disease severity. The application of multichannel impedance with pH monitoring allows detection of acidic and nonacidic reflux events during sleep and also helps to elucidate the physiologic response of the esophagus to these events during sleep. The significance of these findings will increase our knowledge of esophageal physiology and the pathologic mechanisms underlying gastroesophageal reflux disease.

Predictors of habitual snoring and obstructive sleep apnea risk in patients with asthma

BACKGROUND

A high prevalence of obstructive sleep apnea (OSA) symptoms was reported in patients with asthma. Our goal was to evaluate factors associated with habitual snoring and OSA risk in these patients.

METHODS

Patients with asthma were surveyed at specialty clinics with the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) and questions about the frequency of asthma symptoms (National Asthma Education and Prevention Program guidelines), followed by medical record review. SA-SDQ scores >or= 36 for men and >or= 32 for women defined high OSA risk. Logistic regression was used to model associations with habitual snoring and high OSA risk.

RESULTS

Among 244 patients, 37% snored habitually and 40% demonstrated high OSA risk. Independent predictors of habitual snoring included gastroesophageal reflux disease (GERD) [odds ratio (OR), 2.19; 95% confidence interval (CI), 1.19 to 4.02] and use of an inhaled corticosteroid (ICS) [OR, 2.66; 95% CI, 1.05 to 6.72]. High OSA risk was predicted by asthma severity step (OR, 1.59; 95% CI, 1.23 to 2.06), GERD (OR, 2.70; 95% CI, 1.51 to 4.83), and ICS use (OR, 4.05; 95% CI, 1.56 to 10.53). Linear, dose-dependent relationships of ICS with habitual snoring and high OSA risk were seen (p = 0.004 and p = 0.0006, respectively). Women demonstrated a 2.11 times greater odds for high OSA risk (95% CI, 1.10 to 4.09) when controlling for the above covariates.

CONCLUSIONS

Symptoms of OSA in patients with asthma are predicted by asthma severity, coexistent GERD, and use of an ICS in a dose-dependent fashion. The well-recognized male gender predominance for OSA symptoms is not apparent in these patients. Further exploration of these relationships may help to explain the increased prevalence of OSA in asthma and provide new insights into the reported female predominance of asthma morbidity.

The effect of hiatal hernia on gastroesophageal reflux disease and influence on proximal and distal esophageal reflux

INTRODUCTION

Gastroesophageal reflux disease (GERD) is a very common disorder that substantially affects the patient's quality of life.

AIM

Our aim was to detect the frequency of GERD in patients with hiatal hernia (HH), to compare the acid reflux pattern in patients with and without HH, and to search the relationship between the erosive gastroesophageal reflux (GER) and HH.

METHODS

Forty patients with HH diagnosed by at least two methods, and 121 patients with GERD as a control group were studied. The frequency of GERD in patients with HH, the acid reflux pattern, the relation of body mass index and erosive esophagitis with HH and control group was studied.

RESULTS

Among patients with HH 67.5% of patients had GER. On comparison of acid reflux pattern, the isolated distal esophageal reflux was seen more in patients with HH than in the control group (P < 0.0001). Erosive GERD was seen more in patients with HH than in the control group (P = 0.017). There was no difference in body mass indices between patients with HH and erosive gastroesophageal reflux disease and patients with HH and non-erosive GERD.

CONCLUSION

Hiatal hernia is very closely associated with GERD, and isolated distal esophageal reflux is seen more in patients with HH than in patients without HH. There is no effect of body mass index on GER in patients with HH.

Obstructive sleep apnoea and nocturnal gastroesophageal reflux are common in lung transplant patients

BACKGROUND AND OBJECTIVE

Gastroesophageal reflux (GOR) has been implicated in the pathogenesis of bronchiolitis obliterans syndrome (BOS), possibly due to pulmonary aspiration of refluxed acid. Risk of aspiration of gastric contents is increased during sleep due to decreased oesophageal clearance mechanisms and may be further increased by the presence of OSA. This study investigated the relationship between nocturnal GOR, OSA and BOS in a group of lung transplant patients.

METHODS

Fourteen lung transplant patients underwent overnight polysomnography with simultaneous dual oesophageal pH monitoring.

RESULTS

Patients had an FEV(1) of 84 +/- 15% of their best post-transplant FEV(1). Six of the 14 patients were in various stages of BOS. The average proportion of time spent overnight with a pH of <4 was 1.7 +/- 3.1%. Increased GOR was evident in 8/14 patients during the postprandial period and/or overnight in the distal and/or proximal oesophagus. All patients had OSA (AHI >5 events per hour). There were no relationships between severity of OSA or GOR and severity of BOS.

CONCLUSION

Both nocturnal GOR and OSA were common in this group of patients but their occurrences were not related. Neither was there any relationship between the presence of nocturnal GOR or OSA and severity of BOS.

Gastroesophageal reflux disease as an etiology of sleep disturbance in subjects with insomnia and minimal reflux symptoms: a pilot study of prevalence and response to therapy

BACKGROUND

Gastroesophageal reflux disease (GERD) is a well-recognized cause of impaired sleep in patients with frequent GERD symptoms, as well as those with sleep apnea. GERD's role in sleep disturbance of minimally symptomatic patients with poor sleep quality is less clear.

AIM

We aimed to define the prevalence of GERD-related sleep disturbance in minimally-symptomatic subjects with demonstrated insomnia, and to assess the changes in sleep efficiency in these subjects after vigorous acid suppression.

METHODS

We recruited subjects aged 18-75 years reporting at least 6 months of insomnia, and sleep difficulty at least three nights per week. Subjects with a BMI > 30, a history of snoring or ongoing use of proton pump inhibitor or H2 receptor antagonist were excluded. Subjects underwent concurrent sleep study with dual channel 24-h pH study. Sleep efficiency, defined as the percentage of time after sleep initiation that the subject actually slept, and spontaneous arousal index, defined as the number of arousals per hour, were calculated. Those with a sleep study demonstrating poor sleep quality (sleep efficiency of < 83%, and > 10 arousals/h for those aged < 45, and > 15 for those who were 45 or older) and no obstructive sleep apnea were treated with rabeprazole 20 mg PO BID x 14 days. After 14 days, the subjects underwent repeat sleep study with pH monitoring. The GERD Symptom Assessment Scale (GSAS), the Epworth Sleepiness Scale (ESS) and the Functional Outcomes of Sleep Questionnaire (FOSQ) were administered to subjects at study inception and after 2 weeks of therapy.

RESULTS

Twenty-four subjects reporting insomnia were enrolled, and 20 met criteria for disordered sleep and no OSA. Seventeen completed both the first and second studies, and 16 were adequate for analysis. Baseline GSAS demonstrated trivial or no reflux symptoms in the cohort (no subject scored > 8 out of 45 on GSAS, corresponding to a median rating of reflux symptoms of "not at all"). Four of 16 subjects (25%) demonstrated abnormal pH studies at baseline. All four had normalization of acid exposures on PPI. After 2 weeks of treatment, three of these four subjects had normalization of sleep efficiency, compared to 4 of 12 of the subjects with normal Johnson-DeMeester scores. Repeated measures analysis showed significant improvement in spontaneous arousal index between the first and second study for the whole group (P < 0.0035). Pre- and post-therapy ESS and FOSQ scores were not significantly different.

CONCLUSIONS

Despite the lack of GERD symptoms, a significant minority of subjects with sleep disturbance have abnormal acid exposures. These preliminary data suggest that aggressive treatment of GERD in such patients may result in improvement in sleep efficiency.

Unrecognized GERD symptoms are associated with excessive daytime sleepiness in patients undergoing sleep studies

Sleep disturbances are commonly reported by patients who suffer from gastroesophageal reflux disease (GERD) but it is uncertain if GERD plays a role in patients with sleep disorders of undetermined origin. The prevalence of GERD in patients with sleep disorders of unknown etiology is uncertain; the aim of this study was to determine this prevalence. Three hundred eighty-five consecutive patients reporting to an outpatient clinic for evaluation of sleep disorders were assessed for their sleepiness in relation to reflux symptom intensity. Reflux symptoms that met the survey criteria for a diagnosis of GERD were present in 45 of the 385 subjects (12.8%). These subjects did not have a diagnosis of GERD and were not being treated. Multiple regression analysis showed that excessive sleepiness was associated with intensity of GERD symptoms. Patients with GERD had significantly higher Epworth sleep scores than patients without GERD (12.8 vs. 10.6; p=0.007), indicating more daytime sleepiness. We conclude that unrecognized and untreated GERD are present in many patients presenting with sleep disorders. Patients with GERD had significantly greater sleepiness. Further studies of the impact of GERD treatment in this population are necessary.

Review article: the pathophysiology of gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease (GERD) is a common condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications.

AIM

To review the current knowledge on the underlying factors contributing to GERD, with particular emphasis on the most recent research.

METHODS

Literature searches were conducted in Medline and EMBASE. The abstracts from recent large congresses were also reviewed to ensure coverage of the latest findings.

RESULTS

The pathophysiological factors causing GERD can be split into those inducing greater exposure of the oesophagus to stomach contents, and those that provide increased perception of reflux or increased mucosal damage. Transient lower oesophageal sphincter relaxations, which are likely to be triggered by gastric distension, appear to be a key physiological cause of GERD. Excessive reflux may also be provoked by impaired oesophageal or gastric clearance mechanisms. Pre-epithelial, epithelial and post-epithelial defences all normally protect the oesophagus from injury, and may be compromised in individuals with GERD. Heartburn could also be caused by oesophageal hypersensitivity as a result of visceral neural pathway dysfunction.

CONCLUSION

The pathophysiology of GERD is multifactorial, and abnormalities in the gastro-oesophageal junction, the stomach, the oesophagus and the nervous system may all contribute to this disease state.

High prevalence of proximal and distal gastroesophageal reflux disease in advanced COPD

BACKGROUND

Gastroesophageal reflux disease (GERD) is common in a variety of chronic respiratory diseases, but little is known about GERD in the setting of COPD. The aims of this study were to determine the prevalence, presentation, and predictors of GERD based on proximal and distal esophageal pH monitoring in patients with severe COPD.

METHODS

Forty-one COPD patients with a mean FEV1 of 24% of predicted underwent dual-probe 24-h esophageal pH monitoring, and 1 patient underwent esophagogastroduodenoscopy.

RESULTS

The prevalence of GERD was 57%. Elevated distal and proximal reflux were present in 41% and 46% of patients undergoing esophageal pH studies, respectively. Fifteen percent of these patients had abnormal proximal reflux despite having normal distal probe results. Most patients with GERD were not receiving acid blockers at the time of their referral, and only one third reported heartburn and/or acid regurgitation during the pH study. Only higher body mass index was predictive of reflux on regression analysis (odds ratio, 1.2; 95% confidence interval, 1.0 to 1.5; p = 0.05).

CONCLUSIONS

GERD is common in advanced COPD. Patients are often asymptomatic and have a relatively high prevalence of isolated abnormal proximal reflux. Dual-probe monitoring is therefore well suited for detecting GERD in patients with advanced COPD.

Safety and feasibility of evaluating airway-protective reflexes during sleep: new technique and preliminary results

BACKGROUND

The airway is vulnerable to aspiration during sleep. The integrity of aerodigestive-protective reflexes during sleep has not been studied previously because of a lack of adequate techniques.

OBJECTIVE

To determine the safety and the feasibility of a new technique to elicit pharyngoglottal closure reflex (PGCR), pharyngo-upper-esophageal sphincter (UES) pressure contractile reflex (PUCR), and reflexive pharyngeal swallow (RPS) during sleep.

SETTING

Outpatient sleep laboratory.

DESIGN AND INTERVENTION

PGCR, PUCR, and RPS were elicited in 3 subjects by injecting colored water into the pharynx through a specially designed UES manometry catheter to which a thin videoendoscope was taped. This assembly was passed transnasally and positioned to obtain UES-pressure recordings and adequate endoscopic glottic views. Sleep was monitored by polysomnography, and all modalities were synchronized by using a timer. Subjects were evaluated while awake and during stage I sleep.

RESULTS

All subjects were monitored for 3 hours of natural sleep, during which several periods of stage I sleep were observed. While awake, PGCR, PUCR, and RPS were elicited in all subjects. During sleep, PGCR was present in all, PUCR in 2, and RPS in 2 (1 after arousal) subjects. Threshold volumes for reflex elicitation were not significantly different between the awake state and stage I sleep. None of the subjects exhibited laryngeal penetration or aspiration.

LIMITATIONS

Small numbers of subjects were studied only in stage I sleep.

CONCLUSIONS

When using the above technique, it is safe and feasible to study aerodigestive reflexes during sleep. Preliminary data suggest that PGCR, PUCR, and RPS can be elicited during sleep.

Modulation of upper and lower esophageal sphincter tone during sleep

BACKGROUND AND PURPOSE

The pressures generated within the upper esophageal sphincter (P(UES)) and lower esophageal sphincter (P(LES)) reflect the integrity of these barriers to gastroesophageal and pharyngoesophageal reflux, respectively. This study sought to describe the effects of sleep, respiration and posture on the function of the UES and the LES and the pressure differentials developed across them.

METHODS

Ten healthy volunteers (7M, 3F: 38+/-10 yr) without a history of sleep-disordered breathing or reflux underwent overnight polysomnography with simultaneous measurement of P(LES) and P(UES) using a purpose-built sleeve device (Dentsleeve). Posture was recorded but not controlled.

RESULTS

Subjects slept for 4.3+/-1.6h. Compared to waking values, both end-inspiratory and end-expiratory Pues were significantly less during slow wave sleep (SWS) (p<0.05). However, P(LES) was unaffected by sleep stage. During wakefulness and all stages of sleep, both P(UES) and P(LES) were greater at end-inspiration than end-expiration (p<0.05). Similar relationships were observed whether subjects were supine or in the lateral decubitus position.

CONCLUSION

Sleep decreases the effectiveness of the UES to act as a barrier to pharyngoesophageal reflux, particularly during slow wave sleep (SWS). UES pressure varies with respiration, with minimal values observed during expiration. Hence, barrier function of the UES appears most impaired during SWS, in the expiratory phase of the respiratory cycle. The LES pressure and its barrier pressure also vary with respiration, being least during expiration. However, unlike the UES, the function of the LES was unaffected by sleep.

Acidic and Non-Acidic Reflux During Sleep Under Conditions of Powerful Acid Suppression

BACKGROUND

During sleep, individuals are uniquely vulnerable to acid reflux. Acid reflux during sleep has been studied by a number of investigators, but non-acid reflux is largely unexplored.

METHODS

In this study, 15 individuals with significant subjective complaints of heartburn were treated with esomeprazole, 40 mg bid, and with placebo, in random order, for 1 week each. After 1 week of treatment, participants underwent combined impedence/pH monitoring and polysomnography. In both drug and placebo conditions, these procedures were done after participants consumed a meal designed to increase the likelihood of reflux events.

RESULTS

Total reflux events and acid reflux events were significantly decreased with proton-pump inhibitor (PPI) treatment as compared to placebo. Nonacid reflux events were more common with PPI treatment as compared to placebo, but this result was not statistically significant. The ratio of non-acidic to acidic events was significantly greater with PPI treatment, however. Similar results were found for reflux events that occurred only during sleep. Proximal migration of acidic vs non-acidic reflux events was found to be similar. There was no difference in sleep architecture between placebo and drug conditions.

CONCLUSION

PPI treatment reduced overall reflux events, but non-acidic reflux events were relatively more likely to occur with PPI treatment. The occurrence of these non-acidic reflux events on PPI might conceivably explain why some individuals continue to have symptoms after PPI treatment.

Reflux events and sleep: are we vulnerable?

This review addresses the changes in the physiologic responses to esophageal acid contact that occur during sleep. The importance of these changes is addressed as they pertain to the development of esophagitis and other complications of gastroesophageal reflux. Sleep results in physiologic changes that impair esophageal acid clearance, thereby creating a vulnerability to the complications of reflux. These complications are generally considered secondary to prolonged acid mucosal contact. Sleep-related reflux also produces a disruption of sleep, which may result in clinical complaints of sleep disturbance and significant daytime consequences, such as sleepiness and diminished work performance. The significance of these sleep-related findings is addressed as they relate to the diagnosis and treatment of gastroesophageal reflux disease.

Effect of hiatal hernia on proximal oesophageal acid clearance in gastro-oesophageal reflux disease patients

BACKGROUND

Proximal acid reflux is common in gastro-oesophageal reflux disease and is a determinant of symptoms. Patients with hiatal hernia complain of more symptoms than those without and are less responsive to proton-pump inhibitors.

AIM

To evaluate the role of hiatal hernia on spatiotemporal characteristics of acid reflux.

METHODS

Thirty seven consecutive gastro-oesophageal reflux disease patients underwent endoscopy, videofluoroscopy, manometry and multichannel 24-h pH test. Data were compared with those of 15 asymptomatic controls. Multivariate linear regression was used for statistical analysis.

RESULTS

At videofluoroscopy, hiatal hernia was found in 16 of 37 patients. The mean size of hiatal hernia was 3.4 cm. Patients showed significantly prolonged acid clearance time, both at proximal and distal oesophagus, compared with controls. Hiatal hernia patients showed a significantly delayed acid clearance, along the oesophageal body, compared with non-hiatal hernia patients. The prolonged acid exposure was maintained during upright and supine position. The presence of hiatal hernia significantly predicted acid clearance delay in the distal and proximal oesophagus [at 10 cm below upper oesophageal sphincter: Delta + 2.5 min (95% confidence interval: 0.4-4.5); P < 0.02].

CONCLUSIONS

The presence of hiatal hernia is a strong predictor of more prolonged proximal oesophageal acid exposure and clearance. Hiatal hernia is likely to play a role in the pathophysiology of gastro-oesophageal reflux disease symptoms, and should be taken into greater consideration in the treatment strategies of the disease.

Influence of sleep stages on esophago-upper esophageal sphincter contractile reflex and secondary esophageal peristalsis

BACKGROUND & AIMS

Airways are most vulnerable to aspiration during sleep. Esophago-upper esophageal sphincter (UES) contractile reflex (EUCR) and secondary peristalsis (2P) have been proposed to protect the airway by reflexively contracting the UES and clearing the esophagus of refluxate, respectively. Our aim was to study EUCR and 2P elicitation in "awake" state, stage II, slow-wave (stage III/IV), and rapid eye movement (REM) sleep.

METHODS

Thirteen healthy volunteers were studied in the supine position using concurrent UES and esophageal manometry and polysomnography. Threshold volume (Tvol) to trigger EUCR and 2P and changes in sleep stages were recorded during injection of 2.7 mL/min water into the proximal esophagus after sleep stages were confirmed.

RESULTS

UES pressure progressively declined with deeper stages of sleep. Tvol for EUCR and 2P elicitation was not significantly different between the stage II and "awake" state (EUCR: 4.0 +/- 1.8 mL vs 6.1 +/- 3.6 mL stage II; 2P: 5.8 +/- 2.2 mL vs 8.0 +/- 4.0 mL stage II). Tvol for EUCR and 2P elicitation during REM sleep were significantly lower than during the stage II and "awake" state (REM EUCR: 2.2 +/- 1.1 mL; 2P: 3.5 +/- 1.2 mL). Arousal and cough preempted development of EUCR and 2P during slow-wave sleep.

CONCLUSIONS

(1) EUCR/2P can be elicited in stage II and REM but is preempted by arousal in slow-wave sleep. (2) Tvol for EUCR/2P elicitation is significantly lower in REM, compared with the stage II and "awake" state, suggesting a heightened sensitivity of these reflexes during REM sleep. (3) Although UES pressure progressively declines with deeper stages of sleep, it can still reflexively contract during REM sleep, despite generalized hypotonia.

Sleep and the Gastrointestinal Tract

In this review, an integration of GI functioning is attempted with regard to its relationship to sleep, how this interaction may lead to complaints of sleep disorders, and the pathogenesis of some GI disorders. Data are presented to support the notion that sleep-related GER is an important factor not only in the development of esophagitis but also in the respiratory complications of GER. Although sensory functioning is altered markedly during sleep with regard to most standard sensory functions (eg, auditory), there seems to be an enhancement of some visceral sensation during sleep that seems to protect the tracheobronchial tree from aspiration of gastric contents reflux during sleep. Patients who have functional bowel disorders reveal an increase in sleep complaints compared with normal volunteers. The actual mechanisms of these disturbances remain somewhat obscure and studies do not demonstrate any consistent abnormalities in sleep patterns of these patients. Some studies show that autonomic functioning during sleep, particularly REM sleep, can distinguish patients who have IBS. Thus, the continued study of sleep and GI functioning promises to create a new dimension in the understanding of the pathophysiology of a variety of GI disorders.

Nighttime reflux is primarily an early event

GOALS

Our clinical impression gleaned from reading large numbers of ambulatory pH studies is that recumbent reflux episodes mostly occur in the early part of the nighttime period. In this study, we propose to test this hypothesis.

STUDY

A total of 201 consecutive pH studies performed in our laboratory between November 2001 and October 2002 were analyzed. Population characteristics: 75 males and 126 females; mean age, 50.4 yrs (range, 16-88 years). Reflux was defined by a drop in pH to less than 4. Abnormal total recumbent reflux was defined as >1.2% time pH < 4. For patients with abnormal recumbent reflux, the recumbent period was divided into two halves and the reflux time in each period was calculated. In all patients, ingestion of a meal within 2 hours of retiring was also identified.

RESULTS

A total of 59 patients had abnormal recumbent reflux: 24 males and 35 females; mean age, 48.9 years. In patients with abnormal recumbent reflux, acid reflux was significantly more frequent in the first half of the recumbent period compared with the second half (median, 6.3%; vs. 0.3%, respectively; P < 0.001; Wilcoxon signed rank test, two-tailed analysis). Those patients (N = 118) having had a meal within 2 hours of retiring were 2.46 times more likely to develop recumbent reflux than those whose last meal was more than 2 hours earlier (N = 83).

CONCLUSION

These results support our hypothesis that nighttime reflux occurs primarily during the first half of the recumbent period. In addition, they reinforce the concept of maintaining control of early nighttime reflux and the importance of counseling patients with nocturnal symptoms against late meals and snacks.

Gastric fullness, physical activity, and proximal extent of gastroesophageal reflux

OBJECTIVES

Proximal extent of gastroesophageal reflux (PER) is relevant for symptoms in GERD patients. It has been suggested that PER is determined by the volume of the refluxate that, in turn, might depend on the degree of gastric fullness. Abdominal straining, during ambulation, increases the likelihood of gastroesophageal reflux. We assessed the influence of gastric fullness and ambulation on proximal extent of reflux.

METHODS

PER was assessed in 37 patients with GERD undergoing ambulatory pH impedance monitoring. In 14 controls and 19 GERD patients, esophageal pH impedance and gastric emptying were also studied simultaneously in stationary conditions. We compared PER during fasting, early postprandial (before half emptying), and late postprandial periods in ambulatory and stationary conditions.

RESULTS

More reflux episodes reached the proximal esophagus in the postprandial period compared to fasting (60%+/-4 vs 29%+/-3, p<0.05). In stationary conditions, early postprandial reflux reached higher proximal extent than late postprandial reflux (15+/-3% vs 8+/-4%, p<0.05). The proportion of reflux events reaching the proximal esophagus was significantly higher in ambulatory than in stationary conditions (29+/-5% vs 15+/-3%, p<0.05).

CONCLUSION

Compared to fasting, reflux episodes occurring after the meals are more likely to reach higher proximal extent, particularly so during the early postprandial period. The highest proportion of postprandial proximal reflux occurred in ambulatory condition. These findings suggest that reducing meal volumes and early postprandial physical activity might contribute to decrease proximal extent of reflux and postprandial GERD symptoms.