Association between obstructive sleep apnea and gastroesophageal reflux disease: A systematic review and meta-analysis

The Lung Microbiome and Its Impact on Obstructive Sleep Apnea: A Diagnostic Frontier

Obstructive sleep apnea (OSA), a prevalent disorder characterized by recurrent upper airway collapse, is increasingly recognized as a systemic inflammatory condition influenced by microbial dysregulation. Emerging evidence underscores the lung microbiome as a mediator in OSA pathophysiology, where dysbiotic shifts driven by intermittent hypoxia, oxidative stress and mechanical airway trauma amplify inflammatory cascades and perpetuate respiratory instability. This review synthesizes current knowledge on the bidirectional interplay between OSA and lung microbial communities. It aims to highlight how hypoxia-induced alterations in microbial ecology disrupt immune homeostasis, while inflammation-driven mucosal injury fosters pathogenic colonization. Clinical correlations between specific taxa like Streptococcus and Prevotella, and disease severity, suggest microbial signatures as novel biomarkers for OSA progression and treatment response. Furthermore, oxidative stress markers and pro-inflammatory cytokines emerge as potential diagnostic tools that bridge microbial dysbiosis with sleep-related outcomes. However, challenges persist in sampling standardization of the low-biomass lower airways, as well as in causative mechanisms linking microbial dysbiosis to OSA pathophysiology. By integrating microbial ecology with precision sleep medicine, this paradigm shift promises to transform OSA management from mechanical stabilization to holistic ecosystem restoration.

A high arousal threshold is associated with nocturnal gastroesophageal reflux in obstructive sleep apnea

OBJECTIVE

Nocturnal gastroesophageal reflux (nGER) was reported to be associated with obstructive sleep apnea (OSA). However, pathophysiological traits in OSA patients with nGER were poorly understood, and arousal threshold (ArTH) might play an important role in this relationship. This study aimed to identify the clinical characteristics of patients with OSA comorbid with nGER, and investigate the association between ArTH and nGER in patients with OSA.

METHODS

482 adult patients with OSA diagnosed by polysomnography (PSG) at Peking University People's Hospital were recruited in this cross-sectional study. nGER presence was defined as typical nGER symptoms (heartburn or acid regurgitation occurring at night which affects sleep, with or without medication treatment) at least once a week in the past four weeks. A low ArTH was predicted based on the following PSG features: a total score of 2 or more, with one point assigned for each of the following criteria: apnea-hypopnea index (AHI) < 30/h, nadir oxygen saturation > 82.5 %, the proportion of hypopneas > 58.3 %, otherwise the ArTH was classified as high. Demographic and anthropometric characteristics, PSG parameters, and questionnaires related to clinical symptoms and comorbidities were obtained. The associations between nGER and clinical features were examined by multivariate logistic regressions.

RESULTS

The prevalence of typical nGER symptoms in patients with OSA was 17.8 %. High ArTH (P = 0.006), BMI ≥28 kg/m2 (P = 0.023), the Epworth Sleepiness Scale (ESS) Scores >16 (P = 0.006), and age over 60 years old (P = 0.002) were associated with a markedly increased risk of nGER in patients with OSA. Notably, in non-obese patients with OSA, a high ArTH not only significantly added to the presence of nGER (OR = 2.905, 95 % CI: 1.352-6.241, P < 0.01) after controlling for age, sex, ESS scores, comorbidities (including hypertension, diabetes mellitus, hyperlipidemia, coronary artery disease, and stroke) and total arousal index, but also associated with nGER symptom frequencies (OR = 2.856, 95 % CI = 1.118-7.294, P = 0.028) after adjusting for age, ESS scores, and medication use.

CONCLUSIONS

A high ArTH is independently associated with nGER in patients with OSA. For non-obese patients with OSA, a high ArTH is not only associated with the presence of nGER but also correlated with nGER symptom frequencies.

Sleep and Respiratory Infections

Sleep disorders that involve circadian rhythm disruption and sleep-disordered breathing (SDB) such as obstructive sleep apnea (OSA) are closely linked to respiratory infections. SDB leads to a proinflammatory state due to intermittent hypoxia, sleep fragmentation, increased oxidative stress, and elevation of inflammatory mediators such as tumor necrosis factor (TNF), interleukin-6 (IL-6), and C-reactive protein (CRP). Furthermore, inflammatory mediator levels correlate with SDB severity, especially in people with OSA. Nocturnal microaspiration, gastroesophageal reflux, and associated comorbidities (e.g., obesity) increase the risk of community-acquired pneumonia, viral infections such as SARS-CoV-2, respiratory complications, and death. OSA has been associated with post-COVID syndrome. It also increases the risk of postoperative complications in both adults and children. Circadian rhythm disorders such as insomnia predispose to immune disorders and increase the risk of infection. Chronic conditions such as bronchiectasis, with or without concomitant cystic fibrosis, can lead to structural sleep changes and increase the risk of OSA due to chronic cough, arousals, aspirations, hypoxia, upper airway edema, and overexpression of proinflammatory cytokines. The protective effect of treatment for sleep disorders against respiratory infection is currently unknown. However, in people presenting with respiratory infection, it is important to test for SDB to prevent complications.

Association between obstructive sleep apnea and multiple adverse clinical outcomes: evidence from an umbrella review

Background and objective

In recent years, there has been a notable rise in awareness regarding obstructive sleep apnea (OSA), and a significant number of potential OSA cases have been identified. Numerous studies have established associations between OSA and various adverse clinical outcomes. This umbrella review aims to summarize and evaluate the available evidence on the relationship between OSA and multiple adverse clinical outcomes.

Methods

PubMed, Embase, and Web of Science databases were systematically searched from inception to September 2023. The AMSTAR and GRADE were used to evaluate the quality of meta-analysis literature and classify the quality of literature evidence. Furthermore, the size of the effect size of the association between OSA and adverse clinical outcomes were assessed by using either a random or fixed-effect model and 95% confidence interval (CI).

Results

A total of 27 meta-analyses were enrolled with 43 adverse clinical outcomes. The umbrella review primarily reported the associations between sleep apnea syndrome and thyroid cancer (HR = 2.32,95%CI:1.35-3.98), kidney cancer (RR = 1.81, 95% CI: 1.20-2.74), liver cancer (RR = 1.19, 95% CI: 1.10-1.29), GERD (Gastroesophageal reflux disease)(OR = 1.53, 95% CI: 1.23-1.91), Atrial fibrillation (AF) (OR = 2.54, 95% CI: 2.20-2.92), osteoporosis (OR = 2.03, 95% CI: 1.26-3.27), and diabetes (OR = 1.40, 95% CI: 1.32-1.48). Overall, the AMSTAR rating scale and GRADE quality assessment included in the meta-analysis were generally low.

Conclusion

Our study shows that OSA is significantly associated with a variety of adverse clinical outcomes, especially an increased risk of certain malignancies, and some adverse clinical outcomes are closely related to OSA severity.

Associations between gastroesophageal reflux disease and otolaryngological diseases

In this study, we conducted a 2-sample Mendelian randomization (MR) analysis to explore the relationship between gastroesophageal reflux disease (GERD) and 16 common otolaryngological diseases. Single-nucleotide polymorphisms that are strongly associated with GERD were used as instrumental variables. The primary estimation of the causal effect utilized the inverse variance weighting method, supplemented by MR Egger, weighted median, simple mode, and weighted mode as alternative methods for estimating the causal effect. Then, sensitivity analyses, including heterogeneity, pleiotropy, and leave-one-out analyses, were performed to verify the robustness of the results. The analysis of MR showed that genetically predicted GERD was associated with an increased risk of acute upper respiratory infection (odds ratios [OR] = 1.1418, 95% confidence intervals [CI] = 1.0664-1.2225, P = 1.00 × 10-4), chronic pharyngitis (OR = 1.483, 95% CI = 1.1495-1.9132, P = 2.40 × 10-3), vocal cord dysfunction (OR = 2.2963, 95% CI = 1.4174-3.7201, P = 7.00 × 10-4), sleep apnea (OR = 1.0022, 95% CI = 1.0009-1.0035, P = 8.00 × 10-4), acute sinusitis (OR = 1.3247, 95% CI = 1.1774-1.4905, P = 2.94 × 10-6), chronic sinusitis (OR = 1.3649, 95% CI = 1.1854-1.5715, P = 1.52 × 10-6), chronic suppurative otitis media (OR = 2.085, 95% CI = 1.3292-3.2704, P = 1.40 × 10-3). Further sensitivity analyses showed no evidence of pleiotropy. The results of this study indicate that GERD may contribute to the development of some otolaryngological diseases. Further research and mechanistic investigations are warranted to elucidate the underlying connections and potential therapeutic implications.

Exploring the silent connection: unveiling the intricate relationship between gastroesophageal reflux disease and sleep apnea syndrome

BACKGROUND

Gastroesophageal reflux disease (GERD) and Sleep Apnea Syndrome (SAS) are two prevalent medical conditions that significantly affect health and quality of life. GERD involves stomach content reflux into the esophagus, while SAS causes recurrent upper airway obstruction during sleep. Despite recent studies hinting at a link, the precise relationship and causality between GERD and SAS remain unclear. Our research uses bidirectional Mendelian randomization to explore this intricate relationship. Additionally, given SAS's high prevalence in cardiovascular patients (40-80%, as highlighted by the American Heart Association), we also investigated its potential association with various cardiovascular diseases to gain new insights into prevention and treatment.

METHODS

This study employed genetic data from large-scale genome-wide association studies (GWAS) on GERD (129,080 cases, 473,524 controls) and SAS (25,008 cases, 391,473 controls) for two-sample Mendelian randomization (MR) analysis to estimate the causal effects of GERD on the risk of SAS. All SNPs were selected using a strict clump window (r2 = 0.001 and kb = 10,000). We initially applied the inverse variance weighted (IVW) method and measured horizontal pleiotropy using MR-Egger, weighted median, and weighted mode methods. I2 index and Cochran Q statistics were used for sensitivity analysis. Funnel plot symmetry of IVW MR estimates versus 1/standard error (1/SEIV) was examined to exclude SNPs potentially causing heterogeneity. Additionally, to exclude reverse causality, bidirectional MR was employed to investigate whether genetic susceptibility to SAS causally influenced the risk of GERD.

RESULTS

GERD was associated with an elevated risk of SAS, demonstrating an odds ratio (OR) of 1.750 (95% CI 1.590-1.930; P < 0.001). Conversely, there was no compelling evidence to indicate a causal link between SAS and the risk of developing GERD, with an OR of 1.000 (95% CI 0.989-1.011; P = 0.964). In addition to the primary findings, our study also revealed significant risks associated with SAS for several cardiovascular conditions, including coronary heart disease, atrial fibrillation, coronary artery disease, heart failure, intracerebral hemorrhage, and ischemic stroke.

CONCLUSION

We discovered compelling evidence indicating an elevated risk of SAS in individuals with GERD, but no significant evidence supporting an increased risk of GERD in those with SAS. Future investigations into SAS risk should take into account the potential therapeutic targeting of GERD. PPI and histamine antagonists can effectively reduce reflux and airway secretions, preventing airway damage and collapse. Furthermore, it is necessary to investigate the underlying mechanisms by which GERD affects SAS. For example, the inflammatory stimulation caused by gastric acid and pepsin in refluxed fluid, as well as the increased tension of bronchial smooth muscle caused by vagus nerve reflex. Thus, early preventive measures can be implemented for potential complications related to SAS.

Risk of Obstructive Sleep Apnea in Patients With Muscle Tension Dysphonia: A Prospective Pilot Study

OBJECTIVE

To investigate the risk of obstructive sleep apnea (OSA) in patients with muscle tension dysphonia (MTD) in comparison to subjects with no dysphonia.

STUDY DESIGN

Prospective cohort study.

METHODS

Patients who were diagnosed with MTD at a tertiary referral center between October 2022 and October 2023 were invited to participate in this study, alongside a healthy control group matched by age and gender, with no history of dysphonia. The risk of OSA was evaluated using the STOP-BANG and Epworth Sleepiness Scale (ESS) questionnaires. Demographic data included age, gender, history of smoking, history of allergy, and history of reflux disease.

RESULTS

A total of 55 patients who had filled the STOP-BANG and ESS questionnaires were enrolled in this study, including 31 patients diagnosed with MTD and 24 healthy subjects. Using the STOP-BANG, two-thirds of the study group had an intermediate-to-high risk of having OSA as compared to 25% of the control group (P = 0.002). The odds of having OSA was 6.3 times among patients with MTD in comparison to controls (OR = 6.3; 95% CI [1.91-20.75]. When using the ESS, nine patients of the study group (29%) exhibited excessive daytime sleepiness compared to none in the control group (P = 0.007).

CONCLUSION

The results of this investigation indicate that the risk of OSA is significantly higher in patients with MTD vs. controls. Patients with MTD were 6.3 times more likely to have an increased risk of OSA in comparison to subjects with no dysphonia. A longitudinal study using objective tests for OSA is needed to establish a cause-effect relationship between OSA and MTD.

Investigating the causal links between obstructive sleep apnea and gastrointestinal diseases mediated by metabolic syndrome through mendelian randomization

Previous studies have pointed to a potential link between Obstructive Sleep Apnea (OSA) and gastrointestinal diseases, suggesting that this relationship might be influenced by the presence of Metabolic Syndrome. However, the exact role of these factors in determining gastrointestinal diseases has not been thoroughly explored. In our study, we utilized data from the Genome-wide Association Studies (GWAS) database, focusing on OSA, metabolic syndrome characteristics such as Body Mass Index (BMI), waist circumference, triglycerides, cholesterol, hypertension, type 2 diabetes, and common gastrointestinal diseases including chronic gastritis, gastric ulcers, irritable bowel syndrome, colorectal cancer, inflammatory bowel disease, cholecystitis, nonalcoholic fatty liver, and dyspepsia. By applying Single-variable and Multi-variable Mendelian randomization methods, we aimed to assess the correlation between OSA and gastrointestinal diseases and investigate whether this correlation is influenced by metabolic syndrome. Our findings revealed a strong association between OSA and an increased risk of chronic gastritis, gastric ulcers, inflammatory bowel disease, and nonalcoholic fatty liver disease. No significant connections were found with irritable bowel syndrome, colorectal cancer, cholecystitis, or dyspepsia. Additionally, OSA was linked to metabolic syndrome traits like BMI, waist circumference, triglycerides, hypertension, and type 2 diabetes. Further analysis showed that BMI, triglycerides, and hypertension were causally related to inflammatory bowel disease; BMI, waist circumference, hypertension, and type 2 diabetes to nonalcoholic fatty liver disease; and triglycerides, hypertension, and type 2 diabetes to chronic gastritis. The multivariable analysis indicated that hypertension mediates the relationship between OSA and chronic gastritis; BMI, triglycerides, and hypertension mediate the link between OSA and inflammatory bowel disease; and waist circumference mediates the connection between OSA and nonalcoholic fatty liver disease. To wrap up, this finding helps us understand how these issues might be related and stresses the role of metabolic syndrome in preventing them, which could lessen their effect on health.

Obstructive Sleep Apnea and Serotoninergic Signalling Pathway: Pathomechanism and Therapeutic Potential

Obstructive Sleep Apnea (OSA) is a disorder characterized by repeated upper airway collapse during sleep, leading to apneas and/or hypopneas, with associated symptoms like intermittent hypoxia and sleep fragmentation. One of the agents contributing to OSA occurrence and development seems to be serotonin (5-HT). Currently, the research focuses on establishing and interlinking OSA pathogenesis and the severity of the disease on the molecular neurotransmitter omnipresent in the human body-serotonin, its pathway, products, receptors, drugs affecting the levels of serotonin, or genetic predisposition. The 5-HT system is associated with numerous physiological processes such as digestion, circulation, sleep, respiration, and muscle tone-all of which are considered factors promoting and influencing the course of OSA because of correlations with comorbid conditions. Comorbidities include obesity, physiological and behavioral disorders as well as cardiovascular diseases. Additionally, both serotonin imbalance and OSA are connected with psychiatric comorbidities, such as depression, anxiety, or cognitive dysfunction. Pharmacological agents that target 5-HT receptors have shown varying degrees of efficacy in reducing the Apnea-Hypopnea Index and improving OSA symptoms. The potential role of the 5-HT signaling pathway in modulating OSA provides a promising avenue for new therapeutic interventions that could accompany the primary treatment of OSA-continuous positive airway pressure. Thus, this review aims to elucidate the complex role of 5-HT and its regulatory mechanisms in OSA pathophysiology, evaluating its potential as a therapeutic target. We also summarize the relationship between 5-HT signaling and various physiological functions, as well as its correlations with comorbid conditions.

Obstructive sleep apnea and 19 gastrointestinal diseases: a Mendelian randomization study

Background

Alterations gastrointestinal diseases (GDs) were reported in individuals with obstructive sleep apnea (OSA), however, the genetic background between OSA and GDs is still unclear.

Methods

This investigation employed Mendelian randomization (MR) analyses to evaluate the causal effect between OSA and 19 types of GDs (gastroesophageal reflux disease (GERD), ulcerative colitis, celiac disease, Crohn's disease, chronic gastritis, irritable bowel syndrome, primary biliary cholangitis, diverticular disease, gastroduodenal ulcer, acute pancreatitis, non-alcoholic fatty liver disease, primary sclerosing cholangitis, cirrhosis, calculus of bile duct, calculus of gallbladder, pancreatic cancer, gastric cancer, colorectal cancer, and esophageal cancer). The inverse-variance weighted (IVW) method was used to evaluate the main effects model of causality.

Results

This MR study suggests that OSA may play a causal role inflammation-related GDs (GERD, PIVW=5.94×10-9; gastroduodenal ulcer, PIVW=1×10-4; chronic gastritis, PIVW=0.0214; ulcerative colitis, PIVW=0.0296), and gallstones (calculi of the gallbladder, PIVW=0.0429; calculi of the bile duct, PIVW=0.0068). After accounting for obesity, type 2 diabetes, smoking, and alcohol consumption, the multivariate MR (MVMR) analysis identified that OSA is an independent risk factor for GERD, gastroduodenal ulcer, and calculus of the bile duct. The reverse MVMR analysis showed a causal effect of GERD on OSA. Besides, we did not find that the predisposition to OSA was associated with 4 cancers.

Conclusion

This MR analysis provides compelling evidence of an independent causal relationship between genetically predicted OSA and an elevated risk of inflammation-related GDs. Besides, no causal association was observed between OSA and cancers. Further studies should be carried out to verify our findings.

Relationship between obstructive sleep apnoea syndrome and gastrointestinal diseases: a systematic review and Meta-analysis

Studies exploring the association between obstructive sleep apnoea syndrome (OSA) and gastrointestinal diseases (GID) are important for enhancing clinical outcomes. This study aimed to systematically assess the association between these two diseases. Adhering to PRISMA guidelines, a comprehensive literature search was conducted across databases including PubMed, Web of Science, Willey Library, Cochrane Library and Scopus. This search focused on English literature published up to January 2024. Literature screening, quality assessment (using the NOS scale) and data extraction were performed by two independent researchers. Statistical analyses were performed using the meta-package of the R.4.2.2 software. An initial screening of 2178 papers was conducted and 11 studies were included. Meta-analysis results showed a significant association between OSA and GID (p < 0.01). Subgroup analyses further indicated a stronger association between OSA and GID in Asian populations compared to Europe and the United States. In addition, both benign and malignant GID were significantly associated with OSA, with a pronounced association for malignant GID than for benign GID. The results of publication bias analysis revealed no significant bias (Begg's test p = 0.45, Egger's test p = 0.60). This study uncovers a notable association between OSA and GID, especially in Asian populations, suggesting that clinicians should consider the potential connection between these two diseases during diagnosis and treatment. However, due to the heterogeneity and limitations of the study, these conclusions need to be further validated through more comprehensive research.

Bidirectional correlation between gastroesophageal reflux disease and sleep problems: a systematic review and meta-analysis

Objectives

Gastroesophageal reflux disease (GERD) and sleep problems are highly prevalent among the general population. Both them are associated with a variety of psychiatric disorders such as depression and anxiety, which is highlighting an underexplored connection between them. This meta-analysis aims to explore the association between sleep problems and GERD.

Methods

We conducted a comprehensive search on PubMed, Cochrane Library, Embase, and Web of Science, using Medical Subject Headings (MeSH) and keywords, covering articles from the inception of the databases until August 2023. Stata statistical software, version 14.0, was utilized for all statistical analyses. A fixed-effects model was applied when p > 0.1 and I2 ≤ 50%, while a random-effects model was employed for high heterogeneity (p < 0.1 and I2 > 50%). Funnel plots and Egger's test were used to assess publication bias.

Results

Involving 22 studies, our meta-analysis revealed that insomnia, sleep disturbance, or short sleep duration significantly increased the risk of GERD (OR = 2.02, 95% CI [1.64-2.49], p < 0.001; I2 = 66.4%; OR = 1.98, 95% CI [1.58-2.50], p < 0.001, I2 = 50.1%; OR = 2.66, 95% CI [2.02-3.15], p < 0.001; I2 = 62.5%, respectively). GERD was associated with an elevated risk of poor sleep quality (OR = 1.47, 95% CI [1.47-1.79], p < 0.001, I2 = 72.4%), sleep disturbance (OR = 1.47, 95% CI [1.24-1.74], p < 0.001, I2 = 71.6%), or short sleep duration (OR = 1.17, 95% CI [1.12-1.21], p < 0.001, I2 = 0).

Conclusion

This meta-analysis establishes a bidirectional relationship between four distinct types of sleep problems and GERD. The findings offer insights for the development of innovative approaches in the treatment of both GERD and sleep problems.

Exploring predictors of dysphagia in survivors of head and neck cancer: A cross-sectional study

PURPOSE

To evaluate the prevalence of dysphagia in survivors of head and neck cancer (sHNC) and to identify the predictors contributing to the development of dysphagia.

METHODS

We enrolled 62 sHNC in a cross-sectional study to check the prevalence of dysphagia in sHNC and to evaluate which factors were influencing the presence of this side effect. Besides dysphagia, sociodemographic and clinical characteristics, oral symptoms, maximal mouth opening (MMO), sleep quality and physical condition were evaluated, and a linear regression analysis was performed to verify which of these outcomes impact dysphagia.

RESULTS

Among all the sHNC, 85.5% presented dysphagia. The linear regression analysis confirmed that 44.9% of the variance in dysphagia was determined by coughing, MMO and sleep quality, being MMO the most powerful predictor, followed by coughing and sleep quality.

CONCLUSION

Dysphagia affected the great majority of sHNC. Moreover, symptoms as coughing, reduced MMO and sleep disorders may act as predictors contributing to the development of dysphagia. Our results emphasize the importance of an early and proper identification of the symptoms as well as an adequate treatment strategy to address the cluster of symptoms that sHNC undergo.