Asthma and obstructive sleep apnea: Unveiling correlations and treatable traits for comprehensive care.

Asthma and obstructive sleep apnea (OSA) are common respiratory disorders. They share characteristics such as airway obstruction, poor sleep quality, and low quality of life. They are often present as comorbidities, along with obesity, gastroesophageal reflux disease (GERD), and allergic rhinitis (AR), which impacts the disease's control. In recent years, there has been discussion about the association between these conditions and their pathophysiological and clinical consequences, resulting in worse health outcomes, increased healthcare resource consumption, prolonged hospital stays, and increased morbidity and mortality. Some studies demonstrate that treatment with continuous positive airway pressure (CPAP) can have a beneficial effect on both pathologies. This review summarizes the existing evidence of the association between asthma and OSA at their pathophysiological, epidemiological, clinical, and therapeutic levels. It intends to raise awareness among healthcare professionals about these conditions and the need for further research.

Is sleep bruxism in obstructive sleep apnea only an oral health related problem?

BACKGROUND: The etiology of sleep bruxism in obstructive sleep apnea (OSA) patients is not yet fully clarified. This prospective clinical study aimed to investigate the connection between probable sleep bruxism, electromyographic muscle tone, and respiratory sleep patterns recorded during polysomnography. METHODS: 106 patients with OSA (74 males, 31 females, mean age: 56.1 ± 11.4 years) were divided into two groups (sleep bruxism: SB; no sleep bruxism: NSB). Probable SB were based on the AASM criteria: self-report of clenching/grinding, orofacial symptoms upon awakening, abnormal tooth wear and hypertrophy of the masseter muscle. Both groups underwent clinical examination for painful muscle symptoms aligned with Temporomandibular Disorders Diagnostic Criteria (DC/TMD), such as myalgia, myofascial pain, and headache attributed to temporomandibular disorder. Additionally, non-complaint positive muscle palpation and orofacial-related limitations (Jaw Functional Limited Scale-20: JFLS-20) were assessed. A one-night polysomnography with electromyographic masseter muscle tone (EMG) measurement was performed. Descriptive data, inter-group comparisons and multivariate logistic regression were calculated. RESULTS: OSA patients had a 37.1% prevalence of SB. EMG muscle tone (N1-N3, REM; P = 0.001) and the number of hypopneas (P = 0.042) were significantly higher in the sleep bruxism group. While measures like apnea-hypopnea-index (AHI), respiratory-disturbance-index (RDI), apnea index (AI), hypopnea-index (HI), number of arousals, and heart rate (1/min) were elevated in sleep bruxers, the differences were not statistically significant. There was no difference in sleep efficiency (SE; P = 0.403). Non-complaint masseter muscle palpation (61.5%; P = 0.015) and myalgia (41%; P = 0.010) were significant higher in SB patients. Multivariate logistic regression showed a significant contribution of EMG muscle tone and JFLS-20 to bruxism risk. CONCLUSION: Increased EMG muscle tone and orofacial limitations can predict sleep bruxism in OSA patients. Besides, SB patients suffer more from sleep disorder breathing. Thus, sleep bruxism seems to be not only an oral health related problem in obstructive apnea. Consequently, interdisciplinary interventions are crucial for effectively treating these patients. TRIAL REGISTRATION: The study was approved by the Ethics Committee of Philipps-University Marburg (reg. no. 13/22-2022) and registered at the "German Clinical Trial Register, DRKS" (DRKS0002959).

Elucidating the association of obstructive sleep apnea with brain structure and cognitive performance.

BACKGROUND: Obstructive sleep apnea (OSA) is a pervasive, chronic sleep-related respiratory condition that causes brain structural alterations and cognitive impairments. However, the causal association of OSA with brain morphology and cognitive performance has not been determined. METHODS: We conducted a two-sample bidirectional Mendelian randomization (MR) analysis to investigate the causal relationship between OSA and a range of neurocognitive characteristics, including brain cortical structure, brain subcortical structure, brain structural change across the lifespan, and cognitive performance. Summary-level GWAS data for OSA from the FinnGen consortium was used to identify genetically predicted OSA. Data regarding neurocognitive characteristics were obtained from published meta-analysis studies. Linkage disequilibrium score regression analysis was employed to reveal genetic correlations between OSA and related traits. RESULTS: Our MR study provided evidence that OSA was found to significantly increase the volume of the hippocampus (IVW ß (95% CI) = 158.997 (76.768 to 241.227), P = 1.51e-04), with no heterogeneity and pleiotropy detected. Nominally causal effects of OSA on brain structures, such as the thickness of the temporal pole with or without global weighted, amygdala structure change, and cerebellum white matter change covering lifespan, were observed. Bidirectional causal links were also detected between brain cortical structure, brain subcortical, cognitive performance, and OSA risk. LDSC regression analysis showed no significant correlation between OSA and hippocampus volume. CONCLUSIONS: Overall, we observed a positive association between genetically predicted OSA and hippocampus volume. These findings may provide new insights into the bidirectional links between OSA and neurocognitive features, including brain morphology and cognitive performance.

Sleep Disorders and Traffic Accidents: Unveiling the Hidden Risks.

BACKGROUND Numerous countries, Vietnam included, have persistently high annual rates of traffic accidents. Despite concerted government efforts to reduce the annual traffic accident rate, the toll of fatalities and consequential injuries from these accidents rises each year. Various factors contribute to these incidents, notably including alcohol consumption while driving, inadequate awareness of traffic regulations, and substandard traffic infrastructure. However, an under-recognized risk in developing nations such as Vietnam is the prevalence of sleep disorders. Conditions such as obstructive sleep apnea syndrome and obesity hypoventilation syndrome, while prevalent, remain inadequately assessed and treated. These disorders represent significant yet largely unaddressed contributors to the heightened risk of traffic accidents. CASE REPORT We describe the case of a 55-year-old Vietnamese man hospitalized due to long-standing respiratory complications and profound daytime sleepiness. Over the past 2 years, the patient gained 10 kg. Consequently, he frequently experienced drowsiness, leading to 4 traffic accidents. Despite previous hospitalizations, this sleep disorder had gone undiagnosed and untreated. Diagnostic assessments confirmed concurrent obstructive sleep apnea and obesity hypoventilation syndrome through polysomnography and blood gas analyses. Treatment involving non-invasive positive airway pressure therapy notably alleviated symptoms and substantially improved his quality of life within a concise 3-month period. CONCLUSIONS Obstructive sleep apnea and obesity hypoventilation syndrome are contributory factors to excessive daytime somnolence, significantly increasing vulnerability to traffic accidents. Regrettably, this critical intersection remains inadequately addressed. Addressing these concerns comprehensively through dedicated research initiatives should be imperative before considering the universal issuance of driver's licenses to all road users in Vietnam.

Reconsidering screening thresholds in health assessments for obstructive sleep apnea using operational and safety incident data.

The rail industry in Australia screens workers for probable obstructive sleep apnea (OSA) due to known safety risks. However, existing criteria to trigger screening only identify a small proportion of workers with OSA. The current study sought to examine the relationship between OSA risk and rail incidents in real-world data from Australian train drivers, and conducted a proof of concept analysis to determine whether more conservative screening criteria are justified. Health assessment (2016-2018) and subsequent rail incident data (2016-2020) were collected from two passenger rail service providers. Predictors included OSA status (confirmed no OSA with a sleep study, controlled OSA, unknown OSA [no recorded sleep assessment data] and confirmed OSA with no indication of treatment); OSA risk according to the current Standard, and OSA risk according to more conservative clinical markers (BMI threshold and cardiometabolic burden). Coded rail safety incidents involving the train driver were included. Data were analysed using zero-inflated negative binomial models to account for over-dispersion with high 0 counts, and rail safety incidents are reported using Incidence Risk Ratios (IRRs). A total of 751 train drivers, typically middle-aged, overweight to obese and mostly men, were included in analyses. There were 43 (5.7%) drivers with confirmed OSA, 62 (8.2%) with controlled OSA, 13 (1.7%) with confirmed no OSA and 633 (84.4%) drivers with unknown OSA. Of the 633 train drivers with unknown OSA status, 21 (3.3%) met 'at risk' criteria for OSA according to the Standard, and incidents were 61% greater (IRR: 1.61, 95% Confidence Interval (CI) 1.02-2.56) in the years following their health assessment compared to drivers who did not meet 'at risk' criteria. A more conservative OSA risk status using lower BMI threshold and cardiometabolic burden identified an additional 30 'at risk' train drivers who had 46% greater incidents compared to drivers who did not meet risk criteria (IRR (95% CI) 1.46 (1.00-2.13)). Our more conservative OSA risk criteria identified more workers, with greater prospective incidents. These findings suggest that existing validated tools could be considered in future iterations of the Standard in order to more sensitively screen for OSA.

Predictors of moderate to severe obstructive sleep apnea in patients with lung cancer.

BACKGROUND AND OBJECTIVES: OSA is a known medical condition that is associated with several comorbidities and affect patients' quality of life. The association between OSA and lung cancer remains debated. Some studies reported increased prevalence of OSA in patients with lung cancer. We aimed to assess predictors of moderate-to-severe OSA in patients with lung cancer. METHODS: We enrolled 153 adult patients who were newly diagnosed with lung cancer. Cardiorespiratory monitoring was performed using home sleep apnea device. We carried out Univariate and multivariate logistic regression analysis on multiple parameters including age, gender, smoking status, neck circumference, waist circumference, BMI, stage and histopathology of lung cancer, presence of superior vena cava obstruction, and performance status to find out the factors that are independently associated with a diagnosis of moderate-to-severe OSA. RESULTS: Our results suggest that poor performance status is the most significant predictor of moderate to severe OSA in patients with lung cancer after controlling for important confounders. CONCLUSION: Performance status is a predictor of moderate to severe OSA in patients with lung cancer in our population of middle eastern ethnicity.

The Role of Obstructive Sleep Apnea in Hypercapnic Respiratory Failure Identified in Critical Care, Inpatient, and Outpatient Settings.

An emerging body of literature describes the prevalence and consequences of hypercapnic respiratory failure. While device qualifications, documentation practices, and previously performed clinical studies often encourage conceptualizing patients as having a single "cause" of hypercapnia, many patients encountered in practice have several contributing conditions. Physiologic and epidemiologic data suggest that sleep-disordered breathing-particularly obstructive sleep apnea (OSA)-often contributes to the development of hypercapnia. In this review, the authors summarize the frequency of contributing conditions to hypercapnic respiratory failure among patients identified in critical care, emergency, and inpatient settings with an aim toward understanding the contribution of OSA to the development of hypercapnia.

Evaluation of airway responsiveness and pulmonary function test results among obese and non-obese patients with obstructive sleep apnea syndrome.

OBJECTIVE: In this research, we aimed to elucidate the effect of obstructive sleep apnea syndrome (OSAS) and obesity on pulmonary volumes and bronchial hyperreactivity, and particularly the effect of supine position on pulmonary volume and functions. PATIENTS AND METHODS: This was a prospective, cross-sectional study with a total of 96 patients (age range, 20-65 years). Based on the body mass index (BMI) and Apnea-Hypopnea Index (AHI) scores, the patients were divided into four groups: Group 1: AHI≥15/h, BMI≥30 kg/m2 (n=24), Group 2: AHI≥15/h, BMI<30 kg/m2 (n=24), Group 3: AHI<15/h, BMI≥30 kg/m2 (n=24), and Group 4: AHI<15/h, BMI<30 kg/m2 (n=24). All patients first had static and dynamic pulmonary function tests and carbon monoxide diffusion tests (TLco and Kco) in the sitting and supine positions. A bronchial provocation test with methacholine was applied to all patients in the sitting position one day later. Analysis of variance (ANOVA) and multivariate linear regression was used in the statistical analysis. RESULTS: Airway responsiveness was observed in 4 of the patients included in the study, and there was no statistically significant difference between the groups. A statistically significant decrease was observed in forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), total lung capacity (TLC) and functional residual capacity (FRC), especially in  Group 1 in sitting position compared to Group 4 (p=0.001, p=0.001, p=0.025, p=0.043, and p=0.001, respectively). Changes in pulmonary functions in the transition from sitting to a supine position did not show any significant difference in the study groups (p<0.05). We observed no difference in the diffusion capacity in the sitting and supine positions among the groups (p<0.05). CONCLUSIONS: The severity of AHI and BMI particularly affect the lower airway, but changes in the position did not show any significant difference in the study groups.

Mechanical Interactions Between the Upper Airway and the Lungs that Affect the Propensity to Obstructive Sleep Apnea in Health and Chronic Lung Disease.

Obstructive sleep apnea (OSA) is a common disorder characterized by repetitive narrowing and collapse of the upper airways during sleep. It is caused by multiple anatomic and nonanatomic factors but end-expiratory lung volume (EELV) is an important factor as increased EELV can stabilize the upper airway via caudal traction forces. EELV is impacted by changes in sleep stages, body position, weight, and chronic lung diseases, and this article reviews the mechanical interactions between the lungs and upper airway that affect the propensity to OSA. In doing so, it highlights the need for additional research in this area.

Association between the triglyceride glucose index and obstructive sleep apnea and its symptoms: results from the NHANES.

BACKGROUND: Certain studies have indicated a link between obstructive sleep apnea and insulin resistance in specific populations. To gain more clarity, extensive research involving a broad sample of the overall population is essential. The primary objective of this study was to investigate this correlation by utilizing data from the National Health and Nutrition Examination Survey database. METHODS: The analysis incorporated data from the National Health and Nutrition Examination Survey database spanning the time periods from 2005 to 2008 and from 2015 to 2018, with a focus on American adults aged 18 years and older after applying weight adjustments. Key variables such as obstructive sleep apnea, triglyceride glucose index, and various confounding factors were considered. A generalized linear logistic regression model was used to investigate the association between obstructive sleep apnea and the triglyceride glucose index, with additional exploration of the consistency of the results through hierarchical analysis and other techniques. RESULTS: The study included participants aged between 18 and 90 years, with an average age of 46.75 years. Among the total sample, 50.76% were male. The triglyceride glucose index demonstrated a diagnostic capability for obstructive sleep apnea, with an AUC of 0.701 (95% CI: 0.6619-0.688). According to the fully adjusted model, individuals in the fourth quartile of the triglyceride glucose index showed an increased likelihood of having obstructive sleep apnea compared to those in the first quartile (OR: 1.45; 95% CI: 1.02-2.06; P < 0.05). Subgroup analysis indicated that male sex (OR: 2.09; 95% CI: 1.76-2.45; P < 0.05), younger age (OR: 2.83; 95% CI: 2.02-3.96; P < 0.05), white ethnicity (OR: 2.29; 95% CI: 1.93-2.73; P < 0.05), and obesity (OR: 1.54; 95% CI: 1.28-1.85; P < 0.05) were correlated with an elevated risk of OSA. CONCLUSIONS: This study demonstrated a strong association between an elevated TG index and OSA. Additionally, the triglyceride glucose index could serve as an independent predictor of obstructive sleep apnea.

Association Between Sleep Apnea Treatment and Health Care Resource Use in Patients With Atrial Fibrillation.

BACKGROUND: Obstructive sleep apnea (OSA) contributes to the generation, recurrence, and perpetuation of atrial fibrillation, and it is associated with worse outcomes. Little is known about the economic impact of OSA therapy in atrial fibrillation. This retrospective cohort study assessed the impact of positive airway pressure (PAP) therapy adherence on health care resource use and costs in patients with OSA and atrial fibrillation. METHODS AND RESULTS: Insurance claims data for ≥1 year before sleep testing and 2 years after device setup were linked with objective PAP therapy use data. PAP adherence was defined from an extension of the US Medicare 90-day definition. Inverse probability of treatment weighting was used to create covariate-balanced PAP adherence groups to mitigate confounding. Of 5867 patients (32% women; mean age, 62.7 years), 41% were adherent, 38% were intermediate, and 21% were nonadherent. Mean±SD number of all-cause emergency department visits (0.61±1.21 versus 0.77±1.55 [P=0.023] versus 0.95±1.90 [P<0.001]), all-cause hospitalizations (0.19±0.69 versus 0.24±0.72 [P=0.002] versus 0.34±1.16 [P<0.001]), and cardiac-related hospitalizations (0.06±0.26 versus 0.09±0.41 [P=0.023] versus 0.10±0.44 [P=0.004]) were significantly lower in adherent versus intermediate and nonadherent patients, as were all-cause inpatient costs ($2200±$8054 versus $3274±$12 065 [P=0.002] versus $4483±$16 499 [P<0.001]). All-cause emergency department costs were significantly lower in adherent and intermediate versus nonadherent patients ($499±$1229 and $563±$1292 versus $691±$1652 [P<0.001 and P=0.002], respectively). CONCLUSIONS: These data suggest clinical and economic benefits of PAP therapy in patients with concomitant OSA and atrial fibrillation. This supports the value of diagnosing and managing OSA and highlights the need for strategies to enhance PAP adherence in this population.

Effects of Obstructive Sleep Apnea on Airway Immunity and Susceptibility to Respiratory Infections.

Obstructive sleep apnea is a prevalent sleep disorder characterized by recurrent episodes of partial or complete upper airway collapse during sleep, leading to disrupted breathing patterns and intermittent hypoxia. OSA results in systemic inflammation but also directly affects the upper and lower airways leading to upregulation of inflammatory pathways and alterations of the local microbiome. These changes result in increased susceptibility to respiratory infections such as influenza, COVID-19, and bacterial pneumonia. This relationship is more complex and bidirectional in individuals with chronic lung disease such as chronic obstructive lung disease, interstitial lung disease and bronchiectasis.

Hypoxic and Autonomic Mechanisms from Sleep-Disordered Breathing Leading to Cardiopulmonary Dysfunction.

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder. Its prevalence has increased due to increasing obesity and improved screening and diagnostic strategies. OSA overlaps with cardiopulmonary diseases to promote intermittent hypoxia and autonomic dysfunction. Intermittent hypoxia increases the risk for oxidative stress and inflammation, which promotes endothelial dysfunction and predisposes to atherosclerosis and other cardiovascular complications. OSA is associated with an increased sympathetic nervous system drive resulting in autonomic dysfunction leading to worsening of cardiopulmonary diseases. Cardiovascular diseases are observed in 40% to 80% of OSA patients. Therefore, it is essential to screen and treat cardiovascular diseases.

Does Obstructive Sleep Apnea Lead to Progression of Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) have important bidirectional relationships that influence the pathophysiology of each disorder. The slim hyperinflated "pink puffer" phenotype of COPD protects against OSA, whereas the heavier "blue bloater" phenotype predisposes to OSA by fluid retention. OSA may aggravate COPD by promoting airway inflammation. COPD-OSA overlap patients have lower quality of life and are at higher risk of cardiovascular comorbidity than either disorder alone due to greater nocturnal oxygen desaturation and sympathetic activation. Management of OSA with positive airway pressure improves COPD outcomes that include lower exacerbation rates compared to untreated patients.

Obstructive Sleep Apnea Effects on Chronic Airway Disease Exacerbations-Missed Opportunities for Improving Outcomes in Chronic Obstructive Pulmonary Disease and Asthma.

In patients with chronic obstructive pulmonary disease (COPD) and asthma, exacerbations determine the natural history of both diseases. Patients with both respiratory diseases who suffer from obstructive sleep apnea (OSA) as a comorbidity (overlap syndromes) have a higher risk of exacerbations and hospitalization. In cases of OSA/COPD and OSA/asthma, continuous positive airway pressure treatment is indicated. Adequate adherence to therapy appears to reduce exacerbations and their severity, especially in OSA/COPD overlap. However, there is a lack of randomized trials that definitively demonstrate this evidence.

Contribution of Obstructive Sleep Apnea to Asthmatic Airway Inflammation and Impact of Its Treatment on the Course of Asthma.

Asthma and obstructive sleep apnea (OSA) are very common respiratory disorders in the general population. Beyond their high prevalence, shared risk factors, and genetic linkages, bidirectional relationships between asthma and OSA exist, each disorder affecting the other's presence and severity. The author reviews here some of the salient links between constituents of the alternative overlap syndrome, that is, OSA comorbid with asthma, with an emphasis on the effects of OSA or its treatment on inflammation in asthma. In the directional relationship from OSA toward asthma, beyond direct influences, multiple factors and comorbidities seem to contribute.

Untreated Obstructive Sleep Apnea in Interstitial Lung Disease and Impact on Interstitial Lung Disease Outcomes.

Subjects with interstitial lung disease (ILD) often suffer from nocturnal cough, insomnia, and poor sleep quality. Subjects with ILD and obstructive sleep apnea (OSA) seem to have relatively mild symptoms from sleep fragmentation compared to subjects with only ILD. The overlap of ILD, OSA, and sleeping hypoxemia may be associated with poor outcome, even though there is no agreement on which sleep parameter is mostly associated with worsening ILD prognosis. Randomized controlled trials are needed to understand when positive airway pressure (PAP) treatment is required in subjects with ILD and OSA and the impact of PAP treatment on ILD progression.