Mechanisms of nocturnal gastroesophageal reflux events in obstructive sleep apnea

Laryngopharyngeal Reflux and Upper Airway Obstruction Patterns in Nonobese Sleep Apnea Patients

OBJECTIVES

The study aims to investigate the relationship between the presence of laryngopharyngeal reflux (LPR) and obstruction levels identified during drug-induced sleep endoscopy (DISE) in obstructive sleep apnea (OSA) among nonobese patients.

METHODS

We conducted a prospective study of 105 adult patients diagnosed with OSA who underwent DISE using propofol sedation from 2019 to 2024 at a tertiary hospital. To control for the confounding impact of obesity on LPR, the study selectively enrolled individuals presenting a body mass index within the normal range. LPR was assessed using Reflux Symptom Index and Reflux Finding Score. DISE was performed to evaluate upper airway obstruction at various levels, documented using the VOTE classification system by three blinded reviewers. Hypertrophy of the lingual and palatine tonsils was graded using a four-point scale.

RESULTS

Approximately 48.57% of 105 patients showed the presence of LPR. The chi-square test demonstrated a statistically significant association between LPR and the level of airway obstruction, particularly at the tongue base (p = 0.039). Lingual tonsil hypertrophy Grade 3 at the tongue base and palatine tonsil hypertrophy Grade 3 at the oropharynx both showed significant overrepresentation, with adjusted residual values of 4.0 and 4.8, respectively. Complete tongue base obstruction showed a statistically significant association with LPR, with a strong predictive value in both univariate (β = 2.325, OR = 10.227, p = 0.007) and multivariate analyses (β = 2.295, OR = 9.921, p = 0.008).

CONCLUSIONS

The presence of LPR in nonobese OSA patients appears to be significantly associated with an increased likelihood of tongue base obstruction.

LEVEL OF EVIDENCE

3 Laryngoscope, 2025.

Crosstalk between gastrointestinal tract disorders and obstructive sleep apnea

PURPOSE

Clinical studies suggested associations between obstructive sleep apnea (OSA) and gastrointestinal tract disorders. This study aims to investigate the genetic causal relationship between OSA and gastrointestinal tract disorders, specifically gastroesophageal reflux disease (GERD) and inflammatory bowel disease (IBD).

METHODS

In this study, we employed two-sample Mendelian Randomization (MR) analysis to investigate the potential relationships between OSA and GERD, and between OSA and IBD. More specifically, the primary analysis utilized inverse variance weighting (IVW). Weighted median, MR Egger, and MR PRESSO were applied to complicate potential violations of MR assumptions. Also, sensitivity analysis was evaluated and similar analysis was performed again after outliers were removed. Additionally, multivariable MR (MVMR) was conducted for associated pairs to adjust for obesity.

RESULTS

Genetically predicted risk of GERD increased OSA risk by approximately 60% (ORIVW = 1.62, 95%CI = [1.43,1.84]) which was also stable by other complicated approaches, and even with BMI adjusted by MVMR (ORadjBMI[95%CI] = 1.26 [1.15,1.37]). Besides, OSA showed a mild causal effect on increased GERD risk after adjusting for obesity (ORadjBMI[95%CI] = 1.05 [1.02,1.08]). Additionally, OSA increased the risks for IBD (ORIVW[95%CI] = 1.36 [1.12,1.65]), including a higher risk of CD (ORIVW[95%CI] = 1.41 [1.08,1.83]), and a trend for increasing UC risk (ORIVW[95%CI] = 1.29 [0.99,1.67]).

CONCLUSION

GERD exerts a substantial causality on increasing the risk of OSA. Conversely, the potential for a causal relationship that OSA contributes to the development of GERD or IBD remains probable. These findings support the crosstalk between gastrointestinal tract disorders and OSA.

Wake up to gastro-oesophageal reflux disease: The interplay between arousal and night-time reflux

This review examines the temporal association between nocturnal gastro-oesophageal reflux and sleep-arousal cycles. Most nocturnal gastro-oesophageal reflux events occur during the awake cycle, and arousals precede most nocturnal gastro-oesophageal reflux events, indicating that arousal from sleep predisposes to nocturnal gastro-oesophageal reflux. This sheds light on the complex relationship between nocturnal gastro-oesophageal reflux and sleep, and has implications for managing nocturnal gastro-oesophageal reflux symptoms. The appearance of symptoms and the pathophysiology of nocturnal gastro-oesophageal reflux are influenced by sleep hygiene, sleep disturbances and the misalignment of circadian rhythms. Nocturnal gastro-oesophageal reflux and its related sleep disorders are prevalent and negatively impact the quality of life. There is conflicting evidence on whether nocturnal gastro-oesophageal reflux and sleep disturbances are causally linked, and whether sleep disturbances drive nocturnal gastro-oesophageal reflux. Poor sleep quality increases oesophageal hypersensitivity and overall acid exposure. The nocturnal gastro-oesophageal reflux is linked to the more severe forms of gastro-oesophageal reflux disease, especially with atypical/extra-oesophageal manifestations and complications of mucosal damage such as oesophagitis and stricture, Barret's oesophagus, and oesophageal adenocarcinoma. This review highlights the role of sleep problems in presenting nocturnal gastro-oesophageal reflux, and the potential benefits of treating sleep disturbances in enhancing patient care and quality of life.

Physiological Archetypes of de novo Gastroesophageal Reflux Disease After Laparoscopic Sleeve Gastrectomy

Laparoscopic Sleeve Gastrectomy (LSG) is the most common bariatric surgery in the world. While clinically effective, recent studies have shown increasingly higher rates of gastroesophageal reflux disease (GERD) and esophageal motility disorders. We reviewed all the literature and unraveled the underlying mechanism of post-LSG GERD. Finally, we propose a new classification to help us understand the disease and guide work-up, treatment, and future refinements in the surgical technique.

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.

CPAP Treatment Improves Quality of Life and Self-perception of Voice Impairment in Patients with OSA

OBJECTIVE

The purpose of this study is to examine vocal fatigue and impairment, gastroesophageal symptoms, dysphagia risk, and sleep-related quality of life in individuals with obstructive sleep apnea (OSA) who have been treated with continuous positive airway pressure (CPAP) compared to those who have not received treatment.

METHODS

Fifty-four participants diagnosed with OSA completed an online research form. Of these, 29 were receiving CPAP treatment, while 25 were not undergoing treatment. The following instruments were used: Vocal Fatigue Index, Voice Handicap Index, Gastroesophageal symptoms, Eating Assessment Tool, and Quebec Sleep Questionnaire.

RESULTS

The group that received CPAP treatment had significantly lower scores in the functional domain and total Voice Handicap Index. They also experienced fewer symptoms of regurgitation, reduced daytime sleepiness, fewer nocturnal symptoms, and better emotional and social interactions in their quality of life compared to the untreated group. There were no significant differences in voice fatigue and dysphagia risk between the groups.

CONCLUSION

Individuals treated with CPAP experience reduced vocal impairment, fewer regurgitation symptoms, and improvement in the emotional and social interactions domains of their quality of life compared to individuals without treatment.

What is the Effect of CPAP Treatment With Humidifier on Vocal Quality?

OBJECTIVE

Evaluate vocal quality in patients with OSA before and after continuous use of CPAP with a humidifier using subjective patient perception and clinical assessment. The hypothesis was that CPAP treatment with a humidifier would benefit voice quality.

STUDY DESIGN

Randomized, sham-controlled, blinded clinical trial.

METHODS

Forty-three natal males with obstructive sleep apnea for whom CPAP treatment was recommended following polysomnography were randomized into two therapy groups: CPAP and Sham-CPAP. Participants completed questionnaires on voice use, a voice self-assessment with the ten-item vocal handicap index (VHI-10), and complementary questionnaires: the Epworth sleepiness scale (ESS), Pittsburgh sleep quality index (PSQI), reflux symptoms index (LPRSI) and oral dryness visual analog scale (DRY). Their voices were recorded at three different times: before CPAP therapy, and after 3 and 6 months of continuous CPAP use. The acoustic voice quality index (AVQI), and an auditory-perceptual judgment (APJ) were also applied before and after the CPAP and Sham treatments.

RESULTS

After 6 months of treatment, the CPAP group presented improvements in their sleep patterns; however, no statistically significant differences were observed between the groups in respect of the results of the voice-related questionnaires, the AVQI values, and the APJ of the voice quality. All of the participants had some degree of vocal deviation at baseline.

CONCLUSIONS

CPAP therapy with a humidifier did not improve vocal quality as evaluated by the clinician or patient self-assessment. However, it did not have any significant negative effects on voice quality, so can be considered safe to use in male OSA patients.

Positive airway pressure treatment affects respiratory symptoms and gastro-oesophageal reflux: the Icelandic Sleep Apnea Cohort Study

Aim

To study the effect of positive airway pressure (PAP) treatment on nocturnal gastro-oesophageal reflux (nGOR) and respiratory symptoms among clinical obstructive sleep apnoea (OSA) patients.

Methods

822 patients newly diagnosed with OSA referred for PAP treatment were recruited. 732 patients had a 2-year follow-up visit with continuous PAP compliance data (366 full PAP users, 366 partial/non-PAP users). They answered questionnaires, including reporting of nGOR, sleep and respiratory symptoms and general health. Patients with nGOR symptoms once a week or more were defined as "with nGOR". Those without nGOR symptoms and nGOR medication were defined as "no nGOR". Others were defined as "possible nGOR".

Results

At 2-year follow-up, PAP treatment among full users resulted in decreased nGOR (adjusted OR 0.58, 95% CI 0.40-0.86) and wheezing (adjusted OR 0.56, 95% CI 0.35-0.88) compared with partial/non-PAP users. Decreased nGOR, among both full and partial/non-users of PAP treatment, was associated with a decrease in productive morning cough (adjusted OR 4.70, 95% CI 2.22-9.99) and a decrease in chronic bronchitis (adjusted OR 3.86, 95% CI 1.74-8.58), but not decreased wheezing (adjusted OR 0.90, 95% CI 0.39-2.08). A mediation analysis found that PAP treatment directly led to a decrease in wheezing, not mediated through nGOR. Conversely, PAP treatment decreased productive cough mediated through a decrease in nGOR.

Conclusion

In an unselected group of OSA patients, PAP treatment for 2 years was associated with a decrease in nGOR and respiratory symptoms. The PAP treatment itself was associated with less wheezing. A decrease in nGOR through PAP treatment was associated with a decrease in productive cough.

Single-centre, single-blinded, randomised, parallel group, feasibility study protocol investigating if mandibular advancement device treatment for obstructive sleep apnoea can reduce nocturnal gastro-oesophageal reflux (MAD-Reflux trial)

INTRODUCTION

Just under half of patients with obstructive sleep apnoea (OSA) also have gastro-oesophageal reflux disease (GORD). These conditions appear to be inter-related and continual positive airway pressure (CPAP) therapy, the gold standard treatment for OSA to prevent airway collapse, has been shown to reduce GORD. As the impact of mandibular advancement devices, a second-line therapy for OSA, on GORD has yet to be investigated, a feasibility study is needed prior to a definitive trial.

METHODS

This will be a single-centre, single-blinded, tertiary-care based, interdisciplinary, parallel randomised controlled study. Potential OSA participants presenting to the sleep department will be pre-screened for GORD using validated questionnaires, consented and invited to receive simultaneous home sleep and oesophageal pH monitoring. Those with confirmed OSA and GORD (n=44) will be randomly allocated to receive either CPAP (n=22) or MAD therapy (n=22). Following successful titration and 3 weeks customisation period, participants will repeat the simultaneous sleep and oesophageal pH monitoring while wearing the device. The number of patients screened for recruitment, drop-out rates, patient feedback of the study protocol, costs of interventions and clinical information to inform a definitive study design will be investigated.

ETHICS AND DISSEMINATION

Health Research Authority approval has been obtained from the Nottingham 2 Research Ethics Committee, ref:22/EM/0157 and the trial has been registered on ISRCTN (https://doi.org/10.1186/ISRCTN16013232). Definitive findings about the feasibility of doing 24 hour pH oesophageal monitoring while doing a home sleep study will be disseminated via clinical and research networks facilitating valuable insights into the simultaneous management of both conditions.

TRIAL REGISTRATION NUMBER

ISRCTN Reg No: 16013232.

Associations between snoring and dental sleep conditions: A systematic review

BACKGROUND

It is important for dentists to know if the presence of snoring is associated with the presence of other dental sleep conditions (e.g. obstructive sleep apnea [OSA], sleep bruxism [SB], gastroesophageal reflux disease [GERD], xerostomia and oro-facial pain). If so, dentists could play a significant role in the early recognition and management of these conditions.

OBJECTIVES

This systematic review aimed to: (i) investigate the associations between the presence of snoring and the presence of other dental sleep conditions; and (ii) determine if it is clinically relevant that dentists assess snoring in their population.

METHODS

The literature search was performed in PubMed and Embase.com in collaboration with a medical librarian. Studies were eligible if they employed regression models to assess whether snoring was associated with other dental sleep conditions, and/or investigated the incidence of snoring in patients with other dental sleep conditions and vice versa.

RESULTS

Of the 5299 retrieved references, 36 eligible studies were included. The available evidence indicates that the presence of snoring is associated with higher probabilities of OSA, GERD and headache. Due to limited evidence and conflicting findings, the currently available articles are not indicative of associations between the presence of snoring and the presence of SB and oral dryness.

CONCLUSION

Within the limitations of this study, it can be concluded that the presence of snoring is associated with higher probabilities of OSA, GERD and headache. Therefore, it is clinically relevant that dentists assess snoring in their patient population.

Relationship between gastroesophageal reflux disease and objective sleep quality

STUDY OBJECTIVES

To objectively characterize (1) the relationship between gastroesophageal reflux disease (GERD) and sleep quality, and (2) the influence of sleep position on this relationship, using in-laboratory polysomnography.

METHODS

We retrospectively analyzed first-night diagnostic in-laboratory polysomnography data for 3411 patients (median age 55 years; 48% male). Medication use and medical condition data were obtained through self-reported questionnaires. Associations between sleep quality and the presence of GERD, and the influence of sleep position on these associations, were analyzed using multivariable linear regression models.

RESULTS

After adjusting for age, sex, body mass index, and relevant comorbidities, GERD was associated with a 3.0% decrease in sleep efficiency, 8.8-minute increase in wake after sleep onset, 24.4-minute increase in rapid eye movement (REM) latency, 13.4-minute decrease in total sleep time, 1.4% decrease in %REM sleep, and 1.5% increase in %N3 sleep. Having both GERD and the majority of sleep on the right side was associated with an 8.6% decrease in sleep efficiency, 27.5-minute increase in wake after sleep onset, 35.6-minute decrease in total sleep time, 2.1% decrease in %REM sleep, and 3.5% increase in %N3 sleep. Having both GERD and the majority of sleep on the left side was associated with an 8.7-minute increase in sleep onset latency.

CONCLUSIONS

GERD is associated with an impairment in objective sleep quality. These associations were more pronounced in right-sided sleep and mostly ameliorated in left-sided sleep. Physicians should recognize the potential for poor sleep quality in patients with GERD and the effect of body position on this relationship.

CITATION

Gurges P, Murray BJ, Boulos MI. Relationship between gastroesophageal reflux disease and objective sleep quality. J Clin Sleep Med. 2022;18(12):2731-2738.

Systematic review: Clinical effectiveness of interventions for the treatment of nocturnal gastroesophageal reflux

BACKGROUND

Nocturnal gastroesophageal reflux symptoms have a major impact on sleep quality and are associated with complicated gastroesophageal reflux disease (GERD). We performed a systematic review to assess the data on the effectiveness of the currently available interventions for the treatment of nocturnal reflux symptoms.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library. All prospective, controlled, and uncontrolled clinical trials in adult patients describing interventions (lifestyle modifications, surgical and pharmacological) for nocturnal gastroesophageal reflux symptoms were assessed for eligibility. A narrative descriptive summary of findings is presented together with summary tables for study characteristics and quality assessment.

KEY RESULTS

The initial reference search yielded 3067 citations; 66 citations were screened in full text, of which 31 articles were included. Studies on lifestyle modifications include head of bed elevation (n = 5), prolonging dinner-to-bed time (n = 2), and promoting left lateral decubitus position (n = 2). Placebo-controlled clinical trials investigating proton pump inhibitors (PPIs) (n = 11) show success rates ranging from 34.4% to 80.8% in the PPI group versus 10.4%-51.7% in the placebo group. Laparoscopic fundoplication is reserved for severe disease only. There is insufficient evidence for a recommendation on the use of nasal continuous positive airway pressure (nCPAP), hypnotics, baclofen and adding bedtime H2 receptor antagonists for reducing nocturnal reflux. CONCLUSION INFERENCES: A sequential treatment strategy, including head of bed elevation, prolonging dinner-to-bed time, promoting left lateral decubitus position and treatment with acid-suppressive medication is recommended for nocturnal gastroesophageal reflux symptoms. Currently, there is insufficient evidence for the use of nCPAP, hypnotics, baclofen and adding bedtime H2 receptor antagonists.

Effect of Continuous Positive Airway Pressure on Chronic Cough in Patients with Obstructive Sleep Apnea and Concomitant Gastroesophageal Reflux

BACKGROUND

Obstructive sleep apnea (OSA) and/or gastroesophageal reflux (GER) may be the contributors to chronic cough in patients with OSA and concomitant GER. This study aimed to explore whether continuous positive airway pressure (CPAP), antireflux treatment and lifestyle modifications improve chronic cough in patients with OSA and concomitant GER.

METHODS

Patients with OSA and concomitant GER who also experienced chronic cough were enrolled, and were divided into two groups. Patients who were treated with general treatment (antireflux treatment and lifestyle modifications) as the control group, and patients who were treated with CPAP and general treatment as the treatment group. Effects of different treatments on chronic cough were assessed, and the association among chronic cough, GER and OSA was evaluated by Pearson's correlation analysis.

RESULTS

The Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale were better in the treatment group after 1 week of treatment; further, the improvement became stronger with the duration of therapy. The gastroesophageal reflux disease questionnaire, visual analog scale (VAS) for cough, and daytime and nighttime cough symptom scores significantly improved in both groups after treatment, whereas this improvement was more significant in the treatment group. Significant associations between the apnea-hypopnea index (AHI) and VAS, weak acid reflux and VAS, and weak acid reflux and AHI were observed.

CONCLUSION

CPAP improved the symptoms of chronic cough and GER in patients with OSA and concomitant GER. AHI and weak acid reflux may be important factors affecting the therapeutic effect of chronic cough in patients with OSA and concomitant GER.

Current status of gastroesophageal reflux disease after sleeve gastrectomy: Still a long way to go

Obesity is a public health concern that is becoming increasingly more serious around the world. Bariatric surgery has become more prevalent due to the obesity epidemic worldwide. Sleeve gastrectomy (SG) is one of the most popular procedures which is safe and efficient. Despite all its favorable features, however, there is an increasing evidence from the literature that the long-term incidence of gastroesophageal reflux disease (GERD) is likely to represent the Achilles' heel of this procedure. Management of severe reflux after SG usually requires revisional surgery. The relationship between SG and GERD needs to be better ascertained in order to prevent related complications, such as esophageal adenocarcinoma. This review attempts to elucidate the effect of SG on GERD and the postoperative management of reflux disease according to recent literature in the hope of drawing the attention of clinicians to postoperative gastroesophageal reflux and guiding the optimal management strategy associated with this "troublesome complication".

The Effect of Bariatric Surgery and Endoscopic Procedures on Gastroesophageal Reflux Disease

Obesity is a global epidemic posing a significant burden on patients and healthcare systems. Gastroesophageal reflux disease is associated with obesity and its prevalence is also growing worldwide. Numerous bariatric surgeries and endoscopic procedures have arisen to assist with weight loss and management of obesity-related conditions. However, the effect of these interventions on reflux is variable and the evidence is often conflicting. To date, Roux-en-Y gastric bypass remains the gold-standard for attaining both reflux and weight loss management, however novel endoscopic techniques are quickly becoming more prevalent as an alternative to surgery. This review aims to summarize currently available endoscopic and surgical weight loss procedures and their impact on reflux symptoms while emphasizing areas requiring additional investigation.

Temporal Relationship Between Night-Time Gastroesophageal Reflux Events and Arousals From Sleep

INTRODUCTION

Night-time gastroesophageal reflux (nGER) symptoms are commonly associated with interrupted sleep. Most studies attempting to understand the relationship between sleep, arousal, and nGER events have been performed so using accelerometry; however, this technology is limited in its ability to precisely determine the temporal association between sleep and reflux events. We aimed to examine the temporal relationships between nGER events and arousal/awakening from sleep using high resolution, in-laboratory polysomnography (PSG).

METHODS

Individuals between 18 and 70 years who had undergone a gastroscopy within 12 months underwent simultaneous 24-hour pH/impedance monitoring and in-laboratory PSG. The temporal relationship between each nGER event and sleep/arousals/awakenings was determined for each participant. Analyses were limited to the sleep period (between "lights out" and time of final waking).

RESULTS

Analyses were conducted on the data from 25 individuals, 64% of whom had nGER episodes (5 ± 5 events per person, range 1-18) and 64% of whom had obstructive sleep apnea (OSA, mean apnea-hypopnea index 20 ± 11 events/hr, range 6-44). There were no differences in PSG-determined sleep duration, sleep efficiency, sleep architecture, arousals/awakenings, or sleep apnea severity between those with nGER and those without. Most nGER events (82%) occurred during a PSG epoch that had been classified as wake. Arousals/awakenings preceded almost all events (73/76), whereas fewer had an arousal/awakening after the event (15/76).

DISCUSSION

As opposed to what is typically assumed, nGER does not seem to cause arousal from sleep, but rather arousal from sleep predisposes to nGER.

Oropharyngeal Microbiome in Obstructive Sleep Apnea: Decreased Diversity and Abundance

STUDY OBJECTIVES

To explore and analyze diversity and abundance of oropharyngeal microbiota in patients with obstructive sleep apnea (OSA).

METHODS

This was a cross-sectional study. Middle-aged men, suspected to have OSA, referred to full-night polysomnography, and willing to provide oropharyngeal swab samples, were consecutively enrolled. OSA severity was assessed by apnea-hypopnea index (AHI) as non-OSA (AHI < 5 events/h) and OSA (AHI ≥ 15 events/h). Bacterial DNA of oropharyngeal samples was extracted and quality test performed. Oropharyngeal microbiota was analyzed using 16S ribosomal DNA (rDNA) sequencing, and bioinformatic analysis carried out after sequencing.

RESULTS

Samples from 51 men (25 in the non-OSA group and 26 in the OSA group) were sent for examination. Of these, 40 samples were found to have sufficient concentration of DNA and were analyzed for bioinformatics. In alpha diversity analysis, the OSA group exhibited significantly lower sobs (198.33 ± 21.71 versus 216.57 ± 26.21, P = .022), chao (221.30 ± 26.62 versus 243.86 ± 26.20, P = .014), ace (222.17 ± 27.15 versus 242.42 ± 25.81, P = .028) and shannon index (3.14 ± 0.23 versus 3.31 ± 0.26, P = .035), suggesting a reduction in microbial species diversity. We further divided participants into non-OSA, moderate OSA, and severe OSA groups and observed a significant decrease in the bacterial biodiversity of OSA groups compared with the non-OSA group, with the most significant decrease occurring in the moderate OSA group. Principal coordinate analysis showed two extremely different oropharyngeal microbial communities in non-OSA and OSA groups. More interestingly, proportion of Neisseria was slightly higher in the severe OSA group (20.64%), followed by the moderate OSA and non-OSA groups (12.57% and 9.69%, respectively). Glaciecola was not detected in the OSA groups compared to the non-OSA group (0 versus 0.772 ± 0.4754, P < .001).

CONCLUSIONS

Middle-aged men with OSA showed less oropharyngeal species diversity and altered abundance, on which further confirmation is warranted.

Gastroesophageal Reflux Disease in Obese Patients

Gastroesophageal reflux disease (GERD) and obesity coexist in many patients in the Western population. The association is not coincidental, since GERD pathophysiology is, in part, linked to obesity. Visceral adipose tissue secretes hormones, which increase the risk of GERD. Obesity increases esophageal motor disorders and higher number of transient lower esophageal sphincter relaxations. Central obesity increases abdominal-thoracic pressure gradient and disrupts the gastroesophageal junction by inducing hiatal hernia formation. Obese patients benefit from weight loss by diet to decrease GERD symptoms; however, Roux-en-Y gastric bypass surgery is associated with a higher weight loss and a decrease in GERD symptoms, and is considered the best way to treat both diseases at the same time.

Comorbid "treatable traits" in difficult asthma: Current evidence and clinical evaluation

The care of patients with difficult-to-control asthma ("difficult asthma") is challenging and costly. Despite high-intensity asthma treatment, these patients experience poor asthma control and face the greatest risk of asthma morbidity and mortality. Poor asthma control is often driven by severe asthma biology, which has appropriately been the focus of intense research and phenotype-driven therapies. However, it is increasingly apparent that extra-pulmonary comorbidities also contribute substantially to poor asthma control and a heightened disease burden. These comorbidities have been proposed as "treatable traits" in chronic airways disease, adding impetus to their evaluation and management in difficult asthma. In this review, eight major asthma-related comorbidities are discussed: rhinitis, chronic rhinosinusitis, gastroesophageal reflux, obstructive sleep apnoea, vocal cord dysfunction, obesity, dysfunctional breathing and anxiety/depression. We describe the prevalence, impact and treatment effects of these comorbidities in the difficult asthma population, emphasizing gaps in the current literature. We examine the associations between individual comorbidities and highlight the potential for comorbidity clusters to exert combined effects on asthma outcomes. We conclude by outlining a pragmatic clinical approach to assess comorbidities in difficult asthma.

Sleep and Nocturnal Gastroesophageal Reflux: An Update

Nocturnal gastroesophageal reflux has been associated with poor sleep quality. Normal physiological adaptations of the aerodigestive system to sleep prolong and intensify nocturnal reflux events. This occurrence leads to sleep disruption, as well as to esophageal, laryngeal, and laryngopharyngeal reflux. Controversy exists on whether OSA and nocturnal reflux are causally linked or merely associated because of shared risk factors. Advances in diagnostic technology have provided new insights into gastroesophageal reflux and the mechanisms of nocturnal reflux during sleep. This update reviews new data on causal links between sleep and gastroesophageal reflux disease.

Relation between globus pharyngeus and OSA in patients examined simultaneously by PSG and pH monitor: A cross sectional study

OBJECTIVE

This was a first cross-sectional single-center study to research the relation between globus pharyngeus, OSA and GERD. Since previous clinical studies have demonstrated a relationship between globus phayrngeus and GERD, however, no reported study on the relation between globus pharyngeus, sleep disorders including OSA, and GERD.

METHODS

Seventeen patients underwent general and otorhinolaryngological examinations and responded to several questionnaires (ESS, PSQI, HADS, and Globus pharyngeus VAS score) at their first visit, and underwent a gastroesophageal test for 24-h pH monitoring and in-laboratory PSG one to two months later.

RESULTS

No significant differences were seen in ESS, PSQI, or HADS scores between the groups. The acid exposure time was not significantly different among the groups. The percentage of esophageal reflux time was higher than the percentage of laryngopharyngeal reflux time through the total time as well as the supine period. This indicated that GERD occurred more frequently than laryngopharyngeal reflux. The entire results showed concurrent OSA in 10 cases (59%) and concurrent GERD in 7 cases (41%). The cases with OSA were treated by CPAP or oral appliance, and those treatments were effective for globus pharyngeus.

CONCLUSION

Although the relation between OSA and globus phayngeus is still controversial, these findings suggest that OSA may be a previously undetected cause of globus pharyngeus. By improving OSA, it may offer an additional option of treatment for those globus pharyngeus cases combined with OSA.

Does CPAP Affect Patient-Reported Voice Outcomes?

Upper aerodigestive tract symptoms are common in patients with obstructive sleep apnea (OSA). It remains unclear whether continuous positive airway pressure (CPAP) improves or worsens these otolaryngology symptoms. As therapy-related side effects limit CPAP adherence, this study aimed to determine if CPAP negatively affects voice, sinonasal, and reflux symptoms of the upper airway. Case series with planned data collection was performed at an academic otolaryngology sleep center. Newly diagnosed patients with OSA were evaluated before and 6 months after initiating CPAP therapy. Data collected included CPAP data download, Reflux Symptom Index (RSI), Epworth Sleepiness Scale (ESS), Voice Handicap Index 10 (VHI-10), Sino-Nasal Questionnaire (SNQ), and oral dryness visual analog scale (VAS). For the 11 CPAP-adherent participants, the RSI significantly improved with CPAP (mean RSI, 22.0-9.5; P = .002); however, the VAS, VHI-10, and SNQ did not change after 6 months of CPAP therapy. In a small sample size, patient-reported voice outcomes (VHI-10) and other upper aerodigestive tract symptoms did not worsen with CPAP; rather, CPAP therapy was associated with a reduction in reflux symptoms.

Changes in the Reflux Symptom Index After Multilevel Surgery for Obstructive Sleep Apnea

Objectives

This study evaluated whether the symptoms of laryngopharyngeal reflux (LPR) change after multilevel surgery for obstructive sleep apnea (OSA).

Methods

Patients who underwent multilevel surgery for OSA between April 2009 and September 2014 were enrolled in this study. All patients underwent preoperative polysomnography prior to surgery and were asked to complete the reflux symptom index (RSI) questionnaire before and after surgery.

Results

Of 73 enrolled patients, 24 (33%) reported an RSI score >13 and were thus classified as having reflux. The mean RSI score before surgery was 11.48±7.95; this number decreased to 4.95±6.19 after surgery (P<0.001). The rate of positive RSI responses was 33% before surgery and 9% after surgery. Each variable that comprised the RSI improved significantly after surgery, except for difficulty with swallowing. Regarding the degree of RSI improvement after surgery, there were no significant differences between subgroups according to sex, age, body mass index, OSA severity, or surgical outcome.

Conclusion

LPR symptoms are prevalent in OSA patients. Treatment for OSA using multilevel surgery potentially reduces the symptoms of LPR.

Mechanism of Gastroesophageal Reflux in Obstructive Sleep Apnea: Airway Obstruction or Obesity?

STUDY OBJECTIVES

This is the first study to compare reflux events during wake and sleep in obese and non-obese individuals with obstructive sleep apnea (OSA) and obese individuals without OSA. The primary aim of the study was to investigate any additive effect of OSA on gastroesophageal reflux (GER) above that of obesity.

METHODS

Twenty obese individuals (body mass index, BMI > 30 kg/m(2)), 9 non-obese individuals (BMI < 30 kg/m(2)) with moderate-to-severe OSA, and 17 obese control subjects (BMI > 30 kg/m(2)) underwent high-resolution esophageal manometry, 24-h esophageal pH-impedance monitoring, and in-laboratory polysomnography.

RESULTS

Mean body mass index was 40 ± 6 and 27 ± 4 kg/m(2) for the obese and non-obese OSA groups, respectively, and 34 ± 5 kg/m(2) for the obese control group. Apnea-hypopnea index (AHI) was 50 ± 30 and 30 ± 25 per hour for the obese and non-obese OSA groups (p > 0.05), significantly higher than that of the obese control group (3 ± 3 per hour, p < 0.05). The two obese groups did not show any significant differences in the total number of acidic reflux events (41 ± 20 vs 28 ± 16); however, the obese OSA group had a greater number of acidic reflux events compared to the non-obese OSA group (22 ± 12 events, p < 0.05). In multivariate analysis, BMI significantly predicted number of acidic reflux events (r(2) = 0.16, p = 0.01) during the 24-h period; however, AHI showed no significant association with any measure of GER severity.

CONCLUSIONS

This study confirms an important role for obesity, rather than OSA per se in the relationship between OSA and GER.

Sleep complaints and sleep breathing disorders in upper and lower obstructive lung diseases

Upper and lower obstructive lung diseases can induce sleep complaints and can be part of the pathogenesis of sleep breathing disorders. In fact, the physiological changes of the pattern of respiration during sleep, added to the airways disease can lead to symptomatic worsening of rhinitis, asthma and chronic obstructive pulmonary diseases (COPD); moreover, their functional and anatomical features can lead to sleep breathing disorders such as obstructive sleep apnea syndrome (OSAS). This review highlights the above-mentioned relationships and the effect of disease management on its comorbidities and the patient's quality of life. Rhinitis, asthma and COPD represent causes of sleep complaints that may be reduced with optimal management of these obstructive airways diseases. Continuous positive airway pressure (CPAP) treatment of sleep apnea needs to be tailored after optimization of the therapy of concomitant diseases, but it can often ameliorate comorbid disease.

Effect of nasal noninvasive respiratory support methods on pharyngeal provocation-induced aerodigestive reflexes in infants

The pharynx is a locus of provocation among infants with aerodigestive morbidities manifesting as dysphagia, life-threatening events, aspiration-pneumonia, atelectasis, and reflux, and such infants often receive nasal respiratory support. We determined the impact of different oxygen delivery methods on pharyngeal stimulation-induced aerodigestive reflexes [room air (RA), nasal cannula (NC), and nasal continuous positive airway pressure (nCPAP)] while hypothesizing that the sensory motor characteristics of putative reflexes are distinct. Thirty eight infants (28.0 ± 0.7 wk gestation) underwent pharyngoesophageal manometry and respiratory inductance plethysmography to determine the effects of graded pharyngeal stimuli (n = 271) on upper and lower esophageal sphincters (UES, LES), swallowing, and deglutition-apnea. Comparisons were made between NC (n = 19), nCPAP (n = 9), and RA (n = 10) groups. Importantly, NC or nCPAP (vs. RA) had: 1) delayed feeding milestones (P < 0.05), 2) increased pharyngeal waveform recruitment and duration, greater UES nadir pressure, decreased esophageal contraction duration, decreased distal esophageal contraction amplitude, and decreased completely propagated esophageal peristalsis (all P < 0.05), and 3) similarly developed UES contractile and LES relaxation reflexes (P > 0.05). We conclude that aerodigestive reflexes were similarly developed in infants using noninvasive respiratory support with adequate upper and lower aerodigestive protection. Increased concern for GERD is unfounded in this population. These infants may benefit from targeted oromotor feeding therapies and safe pharyngeal bolus transit to accelerate feeding milestones.

Meta-analysis of the effect of proton pump inhibitors on obstructive sleep apnea symptoms and indices in patients with gastroesophageal reflux disease

This study was designed to assess evidence for an association between the treatment of gastroesophageal reflux disease (GERD) with proton pump inhibitors (PPIs) and improvement in obstructive sleep apnea (OSA). We conducted a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies to evaluate the treatment effect of PPIs on OSA symptoms and indices in patients with GERD. EMBASE, MEDLINE, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and ClinicalTrials.gov were reviewed up to October 2014. From 238 articles, two randomized trials and four prospective cohort studies were selected. In four cohort studies there were no differences in the apnea-hypopnea indices before and after treatment with PPIs (standard mean difference, 0.21; 95% confidence interval, -0.11 to 0.54). There was moderate heterogeneity among these studies. Two cohort studies revealed significantly decreased apnea indices after treatment (percent change, 31% and 35%), but one showed no significant difference. A significant improvement in the Epworth Sleepiness Scale was observed in three cohort studies and one trial. The frequency of apnea attacks recorded in diaries was decreased by 73% in one trial. In conclusion, available studies do not provide enough evidence to make firm conclusions about the effects of PPI treatment on OSA symptoms and indices in patients with concomitant GERD. Controlled clinical trials with larger sample sizes are needed to evaluate these associations. We recommend PPIs in OSA patients with concomitant GERD to treat reflux symptoms. This treatment may improve the quality of sleep without any effect on apnea-hypopnea indices.

Gastroesophageal reflux disease in the obese: Pathophysiology and treatment

Obesity is a condition that has increased all over the world in the last 3 decades. Overweight and gastroesophageal reflux disease (GERD) are related. GERD may have different causative factors in the obese compared with lean individuals. This review focuses on the proper treatment for GERD in the obese based on its pathophysiology. Increased abdominal pressure may play a more significant role in obese subjects with GERD than the defective esophagogastric barrier usually found in nonobese individuals. A fundoplication may be used to treat GERD in these individuals; however, outcomes may be not as good as in nonobese patients and it does not act on the pathophysiology of the disease. All bariatric techniques may ameliorate GERD symptoms owing to a decrease in abdominal pressure secondary to weight loss. However, some operations may lead to a disruption of natural anatomic antireflux mechanisms or even lead to slow gastric emptying and/or esophageal clearance and thus be a refluxogenic procedure. Roux-en-Y gastric bypass decreases both acid and bile reflux from the stomach into the esophagus. On the other hand, gastric banding is a refluxogenic operation, and sleeve gastrectomy may show different outcomes based on the anatomy of the gastric tube.

Nasal continuous positive airway pressure inhibits gastroesophageal reflux in newborn lambs

Background

Using esophageal pHmetry, nasal CPAP (nCPAP) has been shown to decrease acid gastroesophageal reflux (GER) in adult humans. Although both GER (mainly non-acid) and nCPAP use are very frequent in newborns, the effect of nCPAP on GER in early life is unknown. Having recently shown that the newborn lamb is a unique model for studying neonatal GER, our main objective was to assess the effect of nCPAP on GER in newborn lambs.

Methods

Eight newborn lambs, aged 2–3 days, were studied. Continuous esophageal pH-Impedance monitoring and polysomnography were performed for six hours during both spontaneous breathing and nCPAP application at 6 cmH₂O (nCPAP6), in a randomized order. Results were compared in the two experimental conditions, as well as without CPAP during the following 6 hours.

Results

i) nCPAP₆ virtually abolished GER [mean ±SD reflux number for 6 h = 9.1±8.6 without nCPAP₆ vs. 0.6±1 with nCPAP₆, P<0.05]; ii) GER number was also reduced during the 6 h-period following nCPAP6 application (18±16 without nCPAP₆ vs. 7±8.1 with nCPAP₆, P<0.05); iii) nCPAP₆ decreased the depth and duration of lower esophageal sphincter relaxation.

Conclusions

nCPAP inhibits GER in the newborn lamb. Further clinical studies using different levels of nasal CPAP are needed to confirm this result in human infants.

Endoscopic assessment of reflux esophagitis concurrent with hiatal hernia in male Japanese patients with obstructive sleep apnea

OBJECTIVE

The pathogenetic relationship underlying the high prevalence of gastroesophageal reflux disease (GERD) in patients with obstructive sleep apnea (OSA) remains unclear. In addition, GERD has not been adequately assessed by endoscopy in patients with OSA. The purpose of this study was to use endoscopy to investigate potential interactions among reflux esophagitis, hiatal hernia (HH) and OSA.

MATERIAL AND METHODS

A total of 243 consecutive male Japanese participants who underwent both overnight ambulatory polygraphic monitoring and esophagogastroduodenoscopy were retrospectively evaluated in a cross-sectional study. The prevalence and severity of HH and reflux esophagitis were assessed according to the Los Angeles classification and the Makuuchi classification, respectively. Associations among reflux esophagitis, HH and OSA were examined by univariate and multivariate analyses.

RESULTS

OSA was diagnosed in 98 individuals (40.3%). Endoscopy-confirmed esophagitis (p = 0.027) and HH (p < 0.001) were significantly more prevalent among patients with OSA. Multivariate regression model analysis adjusted for age, body mass index, visceral obesity represented by waist circumference, presence of OSA, concurrence of OSA and HH, smoking, and alcohol consumption yielded OSA as the only variable significantly associated with HH (odds ratio [OR], 2.60; 95% confidence interval [CI], 1.35-4.99; p = 0.004), while concurrence of OSA and HH was related to reflux esophagitis (OR, 3.59; CI, 1.87-6.92; p < 0.001).

CONCLUSIONS

OSA was associated with HH and concurrent OSA and HH with reflux esophagitis in male Japanese patients with OSA. Our results support the hypothesis that complicating HH may link reflux esophagitis to OSA.

Coenzyme Q10 benefits symptoms in Gulf War veterans: results of a randomized double-blind study

We sought to assess whether coenzyme Q10 (CoQ10) benefits the chronic multisymptom problems that affect one-quarter to one-third of 1990-1 Gulf War veterans, using a randomized, double-blind, placebo-controlled study. Participants were 46 veterans meeting Kansas and Centers for Disease Control criteria for Gulf War illness. Intervention was PharmaNord (Denmark) CoQ10 100 mg per day (Q100), 300 mg per day (Q300), or an identical-appearing placebo for 3.5 ± 0.5 months. General self-rated health (GSRH), the primary outcome, differed across randomization arms at baseline, and sex significantly predicted GSRH change, compelling adjustment for baseline GSRH and prompting sex-stratified analysis. GSRH showed no significant benefit in the combined-sex sample. Among males (85% of participants), Q100 significantly benefited GSRH versus placebo and versus Q300, providing emphasis on Q100. Physical function (summary performance score, SPS) improved on Q100 versus placebo. A rise in CoQ10 approached significance as a predictor of improvement in GSRH and significantly predicted SPS improvement. Among 20 symptoms each present in half or more of the enrolled veterans, direction-of-difference on Q100 versus placebo was favorable for all except sleep problems; sign test 19:1, p=0.00004) with several symptoms individually significant. Significance for these symptoms despite the small sample underscores large effect sizes, and an apparent relation of key outcomes to CoQ10 change increases prospects for causality. In conclusion, Q100 conferred benefit to physical function and symptoms in veterans with Gulf War illness. Examination in a larger sample is warranted, and findings from this study can inform the conduct of a larger trial.

Sleep in patients with restrictive lung disease

Restrictive lung disease leads to ventilatory defects and diffusion impairments. These changes may contribute to abnormal nocturnal pathophysiology, including sleep architecture disruption and impaired ventilation and oxygenation. Patients with restrictive lung disease may suffer significant daytime fatigue and dysfunction. Hypercarbia and hypoxemia during sleep may impact progression of lung disease and related symptoms. Little is known about the impact of treatment of sleep disruption on sleep quality and overall prognosis in restrictive lung disease. This review discusses the pathophysiology of sleep and comorbid sleep disorders in restrictive lung diseases including interstitial lung disease, neuromuscular disease, and obesity hypoventilation syndrome.

Systematic review: relationships between sleep and gastro-oesophageal reflux

BACKGROUND

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

AIM

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

METHODS

Studies identified by systematic literature searches were assessed.

RESULTS

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

CONCLUSIONS

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

Sleep-disordered breathing

PURPOSE OF REVIEW

This article introduces readers to the clinical presentation, diagnosis, and treatment of sleep-disordered breathing and reviews the associated risk factors and health consequences.

RECENT FINDINGS

Sleep-disordered breathing is associated with significant impairments in daytime alertness and cognitive function as well as adverse health outcomes. The initial treatment of choice is positive airway pressure. Improvements in technology and mask delivery systems have helped to make this treatment more comfortable and convenient for many patients.

SUMMARY

Sleep-disordered breathing, particularly in the form of obstructive sleep apnea, is highly prevalent in the general population and has important implications for neurology patients. Sleep-disordered breathing is characterized by repetitive periods of cessation in breathing, termed apneas, or reductions in the amplitude of a breath, known as hypopneas, that occur during sleep. These events are frequently associated with fragmentation of sleep, declines in oxygen saturation, and sympathetic nervous system activation with heart rate and blood pressure elevation. Obstructive sleep apnea, which represents cessation of airflow, develops because of factors such as anatomic obstruction of the upper airway related to obesity, excess tissue bulk in the pharynx, and changes in muscle tone and nerve activity during sleep. Central sleep apnea represents cessation of airflow along with absence or significant reduction in respiratory effort during sleep and is more commonly found in the setting of congestive heart failure, neurologic disorders, or cardiopulmonary disease.

Anti-acid treatment and disease progression in idiopathic pulmonary fibrosis: an analysis of data from three randomised controlled trials

BACKGROUND

Abnormal acid gastro-oesophageal reflux is common in patients with idiopathic pulmonary fibrosis (IPF) and is considered a risk factor for development of IPF. Retrospective studies have shown improved outcomes in patients given anti-acid treatment. The aim of this study was to investigate the association between anti-acid treatment and disease progression in IPF.

METHODS

In an analysis of data from three randomised controlled trials, we identified patients with IPF assigned to receive placebo. Case report forms had been designed to prospectively obtain data about diagnosis and treatment of abnormal acid gastro-oesophageal reflux in each trial. The primary outcome was estimated change in forced vital capacity (FVC) at 30 weeks (mean follow-up) in patients who were and were not using a proton-pump inhibitor or histamine-receptor-2 (H2) blocker.

FINDINGS

Of the 242 patients randomly assigned to the placebo groups of the three trials, 124 (51%) were taking a proton-pump inhibitor or H2 blocker at enrolment. After adjustment for sex, baseline FVC as a percentage of predicted, and baseline diffusing capacity of the lung for carbon monoxide as a percentage of predicted, patients taking anti-acid treatment at baseline had a smaller decrease in FVC at 30 weeks (-0·06 L, 95% CI -0·11 to -0·01) than did those not taking anti-acid treatment (-0·12 L, -0·17 to -0·08; difference 0·07 L, 95% CI 0-0·14; p=0·05).

INTERPRETATION

Anti-acid treatment could be beneficial in patients with IPF, and abnormal acid gastro-oesophageal reflux seems to contribute to disease progression. Controlled clinical trials of anti-acid treatments are now needed.

FUNDING

National Institutes of Health.

Barrett's esophagus and the risk of obstructive sleep apnea: a case-control study

BACKGROUND

Prior studies suggest that obstructive sleep apnea may be associated with gastroesophageal reflux disease, a strong risk factor for Barrett's esophagus. The goals of this pilot case-control study were to determine whether Barrett's esophagus patients have an increased likelihood of obstructive sleep apnea and to determine whether nocturnal gastroesophageal reflux symptoms affect the relationship between Barrett's esophagus and obstructive sleep apnea risk.

METHODS

Patients with Barrett's esophagus completed the Berlin Questionnaire, a validated survey instrument identifying subjects at high risk for obstructive sleep apnea. Two outpatient control groups were recruited: 1) EGD Group, subjects matched to Barrett's esophagus cases by age, race, and gender with esophagogastroduodenoscopy negative for Barrett's esophagus; and 2) Colonoscopy Group, patients getting colonoscopy. Rates of scoring at high risk for obstructive sleep apnea were compared. Respondents were also questioned regarding severity of their typical gastroesophageal reflux symptoms and presence of nocturnal gastroesophageal reflux symptoms.

RESULTS

The study included 287 patients (54 Barrett's esophagus, 62 EGD, and 171 colonoscopy subjects). Barrett's esophagus patients were slightly older than colonoscopy patients and more obese. 56% (n = 30) of Barrett's esophagus subjects scored at high risk for obstructive sleep apnea, compared with 42% (n = 26) of EGD subjects (OR 1.73, 95% CI [0.83, 3.62]) and 37% (n = 64) of colonoscopy patients (OR 2.08, 95% CI [1.12, 3.88]). The association between Barrett's esophagus and scoring at high risk for obstructive sleep apnea compared with colonoscopy patients disappeared after adjusting for age. Barrett's esophagus patients reported more severe typical heartburn and regurgitation symptoms than either control group. Among all subjects, patients with nocturnal reflux symptoms were more likely to score at high risk for obstructive sleep apnea than patients without nocturnal reflux.

CONCLUSIONS

In this pilot study, a high proportion of Barrett's esophagus subjects scored at high risk for obstructive sleep apnea. Having Barrett's esophagus was associated with more severe gastroesophageal reflux symptoms, and nocturnal reflux symptoms were associated with scoring at high risk for obstructive sleep apnea. The need for obstructive sleep apnea screening in Barrett's esophagus patients with nocturnal gastroesophageal reflux symptoms should be further evaluated.

Gastroesophageal and laryngopharyngeal reflux profiles in patients with obstructive sleep apnea/hypopnea syndrome as determined by combined multichannel intraluminal impedance-pH monitoring

BACKGROUND

The profiles of gastroesophageal reflux (GER) and laryngopharyngeal reflux (LPR) in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) have never been explored. The aim of the study was to investigate the reflux profile in OSAHS patients.

METHODS

Consecutive snoring out-patients suspected with having OSAHS and 20 healthy volunteers were included. All subjects underwent simultaneous 24-h combined multichannel intraluminal impedance-pH (MII-pH) monitoring and polysomnography. Obstructive sleep apnea/hypopnea syndrome was defined when the apnea/hypopnea index was over 5. Stepwise multiple logistic regression analysis was performed to determine the predictor for OSAHS.

KEY RESULTS

Fifty-three patients were included, 37 with and 16 without OSAHS. The prevalence of reflux symptoms was similar between OSAHS (35.1%) and non-OSHAS (37.5%) patients. More OSAHS patients, compared with non-OSAHS patients and healthy volunteers, had pathologic acid GER, nocturnal acid GER, and prolonged acid clearance (P < 0.001). However, no difference in non-acid reflux episodes was observed among the three groups. Laryngopharyngeal reflux was detected in 51.4%, 43.8%, and 35.0% of OSAHS, non-OSAHS, and healthy volunteers, respectively (P = 0.034). In OSAHS patients, there was no difference in the sleep parameters between patients with and without LPR. Body mass index was the only predictor of OSAHS in the regression analysis.

CONCLUSIONS & INFERENCES

OSAHS patients have more pathologic acid GER and prolonged acid clearance than non-OSAHS patients whereas non-acid reflux was similar between the two groups. However, BMI, not GER, is the only independent predictor for OSAHS. Laryngopharyngeal reflux occurs in more than half of OSAHS patients despite no significant association with OSAHS.

Chronic cough and OSA: a new association?

Chronic cough is defined as cough lasting more than 2 months. Common causes for chronic cough in nonsmokers with normal chest radiographs and pulmonary functions include gastroesophageal reflux disease (GERD), cough-variant asthma (CVA), and upper airway cough syndrome (UACS). Current guidelines recommend diagnosing the etiology of chronic cough based upon the results of therapy for suspected GERD, CVA, and UACS. Despite following current recommendations for diagnosis and treatment, the cause for a significant proportion of chronic cough remains unexplained.Recent reports indicate the resolution of chronic cough following treatment of concomitantly diagnosed obstructive sleep apnea (OSA). Whether this represents a co-occurrence of two commonly prevalent disorders or a pathophysiologic relationship between OSA and cough remains unknown. This review offers insights into a pathophysiologic link between OSA and the commonly purported etiologies for cough, namely, GERD, UACS, and CVA. In addition, evidence for a relationship between airway inflammation that can trigger or perpetuate cough and OSA is discussed. This review explores mechanisms by which nocturnal continuous positive airway therapy resolves cough by improving underlying airway inflammation secondary to OSA and impacts upon GERD, CVA, and UACS.