The overlaps of asthma or COPD with OSA: A focused review

Sleep disordered breathing: OSA-COPD overlap

INTRODUCTION

Sleep has important effects on breathing and gas exchange that may have negative consequences in patients with chronic obstructive pulmonary disease (COPD). COPD and obstructive sleep apnea (OSA) are highly prevalent and may coexist, which is referred to as the overlap syndrome.

AREAS COVERED

The probability of OSA-COPD overlap represents the balance of protective and promoting factors such as hyperinflation and fluid retention; thus, different clinical COPD phenotypes influence the likelihood of comorbid OSA. The clinical presentation of OSA-COPD overlap is nonspecific, and the diagnosis requires clinical awareness to identify patients needing overnight studies. Both COPD and OSA are associated with a range of overlapping physiological and biological disturbances including hypoxia and inflammation that contribute to cardiovascular comorbidities. The management of OSA-COPD overlap patients differs from those with COPD alone and the survival of overlap patients treated with positive airway pressure (PAP) is superior to those untreated.

EXPERT OPINION

The recognition of OSA-COPD overlap has important clinical relevance because of its impact on outcomes and management. Management of the overlap should address both sleep quality and disordered gas exchange. PAP therapy has demonstrated reductions in COPD exacerbations, hospitalizations, healthcare costs and mortality in overlap patients.

Intermittent Versus Sustained Hypoxemia from Sleep-disordered Breathing: Outcomes in Patients with Chronic Lung Disease and High Altitude

In a variety of physiologic and pathologic states, people may experience both chronic sustained hypoxemia and intermittent hypoxemia ("combined" or "overlap" hypoxemia). In general, hypoxemia in such instances predicts a variety of maladaptive outcomes, including excess cardiovascular disease or mortality. However, hypoxemia may be one of the myriad phenotypic effects in such states, making it difficult to ascertain whether adverse outcomes are primarily driven by hypoxemia, and if so, whether these effects are due to intermittent versus sustained hypoxemia.

A pilot study to assess the effects of preventing fluid retention in the legs by wearing compression stockings on overnight airway narrowing in mild asthma

PURPOSE

Nocturnal asthma is a sign of asthma worsening and could be partially due to more fluid drawn into the thorax during sleep by gravitational force and/or pharyngeal collapse in those with obstructive sleep apnea. Wearing compression stockings during the day reduces fluid shift from the legs to the neck overnight. However, the potential effect of wearing compression stockings to reduce fluid accumulation in the leg and to improve nocturnal small airway narrowing in patients with asthma has not been investigated. This study investigates whether reducing leg fluid volume by wearing compression stockings during the day would attenuate small airway narrowing in patients with asthma before and after sleep.

METHODS

We enrolled 11 participants with asthma. All participants underwent overnight polysomnography with or without wearing compression stockings for 2 weeks. Before and after sleep, leg fluid volume (LFV) was measured by bioelectrical impedance, and airway narrowing was primarily assessed by respiratory system resistance and reactance at 5 Hz (R5 and X5 respectively) using oscillometry.

RESULTS

After 2 weeks of wearing compression stockings, the LFV measured in the evening was reduced (∆ =  - 192.6 ± 248.3 ml, p = 0.02), and R5 and X5 improved (∆ =  - 0.7 ± 0.9 cmH2O/L/s, p = 0.03 and 0.2 ± 1.4 cmH2O/L/s, p = 0.05 respectively). No changes were observed in the morning.

CONCLUSIONS

Preventing fluid retention in the legs by wearing compression stockings for 2 weeks during the day, reduced LFV and airway narrowing in the evening in all participants with asthma, but not in the morning after sleep.

The clinical and hemodynamic characteristics of pulmonary hypertension in patients with OSA-COPD overlap syndrome

BACKGROUND

Our study aimed to assess the clinical and hemodynamic characteristics of pulmonary hypertension (PH) in patients with overlapping obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD), referred to OSA-COPD overlap syndrome (OS).

METHODS

We enrolled a total of 116 patients with OS, COPD, or OSA who underwent right heart catheterization (RHC) due to suspected PH. We conducted a retrospective analysis of the clinical and hemodynamic characteristics of these patients.

RESULTS

Among the three groups (OS group, n = 26; COPD group, n = 36; OSA group, n = 54), the prevalence of PH was higher in the OS group (n = 17, 65.4%)compared to OSA group (n = 26,48.1%) and COPD group (n = 20,55.6 %). Among three groups with PH, the superior vena cava pressure (CVP) and right ventricular pressure (RAP) were higher in the OS group than in the OSA group (P < 0.05). Patients in the OS and COPD groups had higher pulmonary artery wedge pressure (PAWP) than in the OSA group (14.88 ± 4.79 mmHg, 13.45 ± 3.68 mmHg vs. 11.00 ± 3.51 mmHg, respectively, P < 0.05). OS patients with PH exhibited higher respiratory event index (REI), time spent with SpO2 <90%, oxygen desaturation index (ODI), minimal SpO2 (MinSpO2) and mean SpO2 (MSpO2) compared to OS patients without PH. After adjusting for potential covariates, we found that MinSpO2 (OR 0.937, 95 % CI 0.882-0.994, P = 0.032), MSpO2 (OR 0.805, 95% CI 0.682-0.949, P = 0.010), time spent with SpO2 <90% (OR 1.422, 95% CI 1.137-1.780, P = 0.002), and FEV1 % pred (OR 0.977, 95 % CI 0.962-0.993, P = 0.005) were related to the development of PH.

CONCLUSIONS

Patients with OS showed higher prevalence of PH, along with higher PAWP, CVP and RAP. Worse nocturnal hypoxemia was found in OS patients with PH.

Increased blood eosinophils and airflow obstruction as new-onset asthma predictors in the elderly: The Nagahama study

BACKGROUND

Asthma in the elderly needs more attention in an aging society. However, it is likely to remain underdiagnosed and undertreated. This study aimed to clarify clinical characteristics of new-onset asthma in the elderly, describing the prevalence, predictive factors, and comorbidities after asthma diagnosis of new-onset asthma in the elderly in the general population.

METHODS

This community-based prospective cohort study enrolled 9804 generally healthy participants (30-74 years old) in Nagahama City, and conducted a follow-up assessment after 5 years. Elderly participants were those aged ≥65 years at baseline. Patients with new-onset asthma were defined as participants without asthma at baseline assessment and with asthma at the follow-up assessment.

RESULTS

Among the 7948 participants analyzed in this study, 28 (1.4%) elderly and 130 (2.2%) non-elderly had new-onset asthma. Multiple logistic regression analysis revealed low forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and high blood eosinophil counts at baseline as predicting factors for new-onset asthma in the elderly. Additionally, subsequent incidence of new-onset asthma was higher in elderly participants with both predictors (high blood eosinophil counts and low FEV1/FVC at baseline) than those with none or one of the predictors before asthma diagnosis. Lastly, elderly patients with new-onset asthma had more frequent comorbidity of moderate to severe sleep disordered breathing than those non-elderly.

CONCLUSIONS

Eosinophilic inflammation and airflow obstruction may predict subsequent new-onset asthma after the age of 65 years. Revealing the characteristics of new-onset asthma in the elderly can aid in the prevention of underdiagnosed asthma.

The pathogenesis of OSA-related hypertension: what are the determining factors?

Sleep-disordered breathing has a relatively high prevalence, which varies from 3-7% in males and from 2-5% in females in the adult population. Studies published in the literature have shown that sleep apnea is closely related to an increased risk of developing various pathologies, among which arterial hypertension stands out. The prevalence of hypertension in patients suffering from obstructive sleep apnea (OSA) ranges from 35-80% and appears to be related to OSA severity. Approximately 40-50% of patients affected by hypertension are also affected by OSA and this association seems to be stronger in young and middle-aged adults (<50 years of age). The primary objective of this narrative review is to provide an update on what are the main contributing comorbidities to the development of a hypertensive state in patients suffering from OSA, an independent risk factor for diurnal hypertension, implicated as a risk factor for the first stroke, recurrent stroke, and post-stroke mortality. There are a lot of factors that contribute to developing a hypertensive state in OSA patients, some more decisive, others less. More evidence from longitudinal studies is needed on the impact of OSA on cardiovascular risk in females, on the causal link between OSA and arterial hypertension or metabolic diseases, like diabetes and glucose intolerance, and the effect of different kinds of OSA treatment.

Revisiting Asthma Obstructive Sleep Apnea Overlap: Current Knowledge and Future Needs

Asthma and obstructive sleep apnea are highly prevalent conditions with a high cost burden. In addition to shared risk factors, existing data suggest a bidirectional relationship between asthma and OSA, where each condition can impact the other. Patients with asthma often complain of sleep fragmentation, nocturnal asthma symptoms, daytime sleepiness, and snoring. The prevalence of OSA increases with asthma severity, as evidenced by multiple large studies. Asthma may lower the threshold for arousal in OSA, resulting in the hypopnea with arousal phenotype. Epidemiologic studies in adults have shown that OSA is associated with worse asthma severity, increased frequency of exacerbation, and poor quality of life. The current literature assessing the relationship among OSA, asthma, and CPAP therapy is heavily dependent on observational studies. There is a need for randomized controlled trials to minimize the interference of confounding shared risk factors.

Association of clinically significant obstructive sleep apnoea with risks of contracting COVID-19 and serious COVID-19 complications: a retrospective population-based study of health administrative data

RATIONALE/OBJECTIVES

Despite plausible pathophysiological mechanisms, more research is needed to confirm the relationship between obstructive sleep apnoea (OSA) and the risk of COVID-19 infection or COVID-19-related serious complications.

METHODS

We conducted a retrospective population-based cohort study using provincial health administrative data (Ontario, Canada). Adults with physician-diagnosed OSA who received positive airway pressure therapy in the 5 years prepandemic (OSA group) were propensity score matched by baseline characteristics to individuals in the general population at low risk of OSA (non-OSA group) using inverse probability of treatment weighting. Weighted HRs of (1) a positive COVID-19 test and (2) COVID-19-related emergency department (ED) visits, hospitalisations, intensive care unit (ICU) admissions and mortality, within 12 months of pandemic onset, were compared between groups. We also evaluated the impact of comorbid cardiometabolic or chronic airways disease.

RESULTS

We identified and matched 324 029 individuals in the OSA group to 4 588 200 individuals in the non-OSA group. Compared with the non-OSA group, those in the OSA group were at a greater hazard of testing positive for COVID-19 (HR=1.17, 95% CI 1.13 to 1.21), having a COVID-19-related ED visit (HR=1.62, 95% CI 1.51 to 1.73), hospitalisation (HR=1.50, 95% CI 1.37 to 1.65) or ICU admission (HR=1.53, 95% CI 1.27 to 1.84). COVID-19-related 30-day mortality was not different (HR=0.98, 95% CI 0.82 to 1.16).We found that for the OSA group, comorbid airways disease but not cardiometabolic conditions increased the hazards of COVID-19-related outcomes, including mortality.

CONCLUSION

In this large population-based study, we demonstrated that a recent diagnosis of OSA requiring treatment was associated with an increased hazard of testing positive for COVID-19 and serious COVID-19-related complications, particularly in those with co-existing chronic airways disease.

Fractional Dynamics Foster Deep Learning of COPD Stage Prediction

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. Current COPD diagnosis (i.e., spirometry) could be unreliable because the test depends on an adequate effort from the tester and testee. Moreover, the early diagnosis of COPD is challenging. The authors address COPD detection by constructing two novel physiological signals datasets (4432 records from 54 patients in the WestRo COPD dataset and 13824 medical records from 534 patients in the WestRo Porti COPD dataset). The authors demonstrate their complex coupled fractal dynamical characteristics and perform a fractional-order dynamics deep learning analysis to diagnose COPD. The authors found that the fractional-order dynamical modeling can extract distinguishing signatures from the physiological signals across patients with all COPD stages-from stage 0 (healthy) to stage 4 (very severe). They use the fractional signatures to develop and train a deep neural network that predicts COPD stages based on the input features (such as thorax breathing effort, respiratory rate, or oxygen saturation). The authors show that the fractional dynamic deep learning model (FDDLM) achieves a COPD prediction accuracy of 98.66% and can serve as a robust alternative to spirometry. The FDDLM also has high accuracy when validated on a dataset with different physiological signals.

A review of upper airway physiology relevant to the delivery and deposition of inhalation aerosols

Developing effective oral inhaled drug delivery treatment strategies for respiratory diseases necessitates a thorough knowledge of the respiratory system physiology, such as the differences in the airway channel's structure and geometry in health and diseases, their surface properties, and mechanisms that maintain their patency. While respiratory diseases, such as chronic obstructive pulmonary disease (COPD) and asthma and their implications on the lower airways have been the core focus of most of the current research, the role of the upper airway in these diseases is less known, especially in the context of inhaled drug delivery. This is despite the fact that the upper airway is the passageway for inhaled drugs to be delivered to the lower airways, and their replicas are indispensable in current standards, such as the cascade impactor experiments for testing inhaled drug delivery technology. This review provides an overview of upper airway collapsibility and their mechanical properties, the effects of age and gender on upper airway geometry, and surface properties. The review also discusses how COPD and asthma affect the upper airway and the typical inhalation flow characteristics exhibited by the patients with these diseases.

Evaluating the Relationship of Airflow Obstruction in COPD with Severity of OSA Among Patients with Overlap Syndrome

Background

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are common diseases affecting millions worldwide. These two diseases have a complex relationship that is not well understood. Previous small studies suggest an inverse relationship of disease severity of OSA with COPD airflow obstruction.

Objective

The aim of this study was to determine if a relationship exists between severity of airflow obstruction in COPD and severity of OSA via apnea hypopnea index obtained during an in-lab baseline polysomnogram using a large quaternary care center cohort.

Methods

From November 2015 through December 2018, 273 patients with confirmed COPD via spirometry and OSA via in-lab baseline polysomnogram were included.

Conclusion

No associations were noted between severity of airflow obstruction in COPD and disease severity of OSA. Given the heterogeneity of these diseases, further exploration of a relationship within disease subtypes is warranted.

Sleep Deficiency, Sleep Apnea, and Chronic Lung Disease

With sleep occupying up to one-third of every adult's life, addressing sleep is essential to overall health. Sleep disturbance and deficiency are common in patients with chronic lung diseases and associated with worse clinical outcomes and poor quality of life. A detailed history incorporating nocturnal respiratory symptoms, symptoms of obstructive sleep apnea (OSA) and restless legs syndrome, symptoms of anxiety and depression, and medications is the first step in identifying and addressing the multiple factors often contributing to sleep deficiency in chronic lung disease. Additional research is needed to better understand the relationship between sleep deficiency and the spectrum of chronic lung diseases.

Review of the prevalence, pathogenesis and management of OSA-COPD overlap

PURPOSE

OSA-COPD overlap is an important and prevalent condition yet remains under-recognised among the vast majority of respiratory health professionals. Patients with OSA-COPD overlap experience more severe respiratory symptoms and worse quality of life, and the relative risk of exacerbations, hospitalisations, and mortality is higher than in either disease state alone.

METHODS

Electronic databases PUBMED and Google Scholar were searched for studies and academic papers that discussed OSA-COPD overlap. Relevant papers that discussed prevalence, pathophysiology, microbiome studies, treatment regimens and outcomes were included in this paper.

RESULTS

High-risk patients with either COPD or OSA should be screened for overlap syndrome as part of routine clinical practice. Screening questionnaires can identify high-risk patients with COPD who may benefit from formal polysomnography. Patients with OSA who are aged over 40 with a significant smoking history or environmental exposures have an increased pre-test probability of obstructive airway disease. The potential roles of gastro-oesophageal reflux disease and lung-gut microbiome are evolving and merit further investigation. A tailored approach to reach a timely diagnosis and thus optimisation of both conditions are key to management. CPAP is the primary therapy for OSA; however, patients with more advanced COPD, with daytime hypercapnia or severe nocturnal desaturations, may benefit from bilevel positive airway pressure.

CONCLUSION

Increased awareness, access to timely investigations and initiation of therapy will improve overall outcomes in OSA-COPD overlap by reducing hospitalisations for exacerbations of COPD and improve mortality rates.

Sleep disorders in elderly population suffering from TB and respiratory diseases

Sleep disorders (SD) are more frequent in the elderly population than younger counterparts. The underlying SD has a more severe impact on cardiorespiratory fitness. In elderly population with respiratory disorders, incidence and baneful influence of sleep disorders are extremely high. Insomnia in elderly is very common probably due to age related changes, underlying co morbidities and multiple medications. With aging there is decrease in duration of slow wave sleep and increase in NREM stage 1 and 2 sleep, which increases number of spontaneous arousals. Compared to younger people, elderly individuals tend to sleep earlier and wake up earlier due to changes in their normal circadian rhythm. Poor sleep quality and restless leg syndrome are higher in Tuberculosis patients. Disturbances in immune regulation due to chronic insomnia may exacerbate chronic infections like TB. Because many respiratory diseases and medications are known to cause sleep disturbances, it is important to assess treatable medical conditions and insomnia inducing medications before initiating hypnotics. Diagnosing sleep disordered breathing (SDB) in ILD patients is particularly important as nocturnal oxygen desaturation is associated with poor prognosis and could possibly be a cause of pulmonary hypertension. In patients with pulmonary hypertension (PH) and underlying obstructive sleep apnoea, CPAP therapy may help to reduce the PH. Addressing sleep disorders will be highly beneficial in elderly COPD patients with sleep disorders. This article reviews different SD, its effects and the treatment benefits in improving the quality of life and reducing the risk of progression of respiratory dysfunction in elderly population with TB and respiratory diseases.

Association of Obstructive Apnea with Thoracic Fluid Shift and Small Airways Narrowing in Asthma During Sleep

RATIONALE

Obstructive sleep apnea (OSA) is highly prevalent among patients with asthma, suggesting a pathophysiological link between the two, but a mechanism for this has not been identified.

HYPOTHESIS

Among patients with asthma, those with OSA will have greater overnight increases in thoracic fluid volume and small airways narrowing than those without OSA.

METHODS

We enrolled 19 participants with asthma: 9 with OSA (apnea-hypopnea index (AHI) ≥10) and 10 without OSA (AHI <10). All participants underwent overnight polysomnography. Before and after sleep, thoracic fluid volume was measured by bioelectrical impedance and small airways narrowing was primarily assessed by respiratory system reactance at 5Hz using oscillometry.

RESULTS

Patients with asthma and OSA (OSA group) had a greater overnight increase in thoracic fluid volume by 120.5 mL than patients without OSA (non-OSA group) (164.4 ± 44.0 vs 43.9 ± 47.3 mL, p=0.006). Compared to the non-OSA group, the OSA group had greater overnight decrease in reactance at 5Hz (-1.08 ± 0.75 vs 0.21 ± 0.27 cmH₂O/L/s, p=0.02), and overnight increase in reactance area (14.81 ± 11.09 vs -1.20 ± 2.46 cmH₂O/L, p=0.04), frequency dependence of resistance (1.02 ± 0.68 vs 0.05 ± 0.18 cmH₂O/L/s, p=0.04), and resonance frequency (2.80 ± 4.14 vs -1.42 ± 2.13 cmH₂O/L/s, p=0.04).

CONCLUSION

Patients with asthma and co-existing OSA had greater overnight accumulation of fluid in the thorax in association with greater small airways narrowing than those without OSA. This suggests OSA could contribute to worsening of asthma at night by increasing fluid accumulation in the thorax.

Additive effects of orchiectomy and intermittent hypoxia on lung mechanics and inflammation in C57BL/6J male mice

NEW FINDINGS

What is the central question of this study? Does endogenous testosterone modulate the consequences of intermittent hypoxia (IH) in the lungs of male mice? What is the main finding and its importance? Orchiectomized mice exposed to IH develop a pattern that is similar to emphysema or obstructive lung disease with elevated lung volumes, low pulmonary elastance during a methacholine challenge test and high counts of lymphocytes in bronchoalveolar lavages. Since low testosterone levels and other respiratory diseases are common in sleep apnoea, there is a clear clinical relevance to these results.

ABSTRACT

We tested the hypothesis that low testosterone levels modulate the pulmonary responses to intermittent hypoxia (IH; used as a model of sleep apnoea (SA)) in male mice. We used intact (SHAM) or orchiectomized (ORX) mice exposed to IH for 14 days (12 h/day, 10 cycles/h, 6% oxygen) or to normoxia (Nx). We first measured ventilation and metabolic rates in freely behaving mice (whole-body plethysmography) and then respiratory mechanics in tracheotomized mice (flexiVent). We assessed the respiratory system resistance and elastance (E_rs ), Newtonian resistance (resistance of the large airways), tissue damping and tissue elastance (H) under baseline conditions and during a methacholine challenge test. We also measured the quasi-static compliance and inspiratory capacity with partial pressure-volume loops. Finally, inflammatory cells were counted in the broncho-alveolar lavage (BAL) and we measured lung volume by water displacement. ORX-IH mice had higher tidal volume, inspiratory capacity and lung volume compared to the other groups, but showed signs of low efficiency of O₂ exchange rate relative to minute ventilation. During the methacholine challenge, orchiectomy decreased the values of most mechanical parameters and IH reduced E_rs and H leading to very low values in ORX-IH mice. Finally, the total number of cells and the number of lymphocytes in BAL were both increased by IH in ORX mice. Since reduced lung elasticity, low O₂ extraction, increased lung volumes and inflammation are signs of emphysematous lung disease, we conclude that testosterone might prevent lung emphysema during IH exposures.

Romanian clinical guideline for diagnosis and treatment of COPD

Chronic obstructive pulmonary disease (COPD) is a disease with increasing prevalence and burden for health systems worldwide. Every country collects its own epidemiological data regarding COPD prevalence, morbidity and mortality while taking steps to educate the population and medical community to improve early detection and treatment. The rising COPD prevalence creates a need for comprehensive guidelines. In 2012 and 2017–2018, the Romanian Society of Pneumology (SRP) organised national inquiries for COPD, while lung physicians in Romania began receiving education regarding the correct algorithms for COPD diagnosis and therapy. During 2019, a Romanian clinical guideline for diagnosis and treatment of COPD was published, and a condensed version of key points from this guideline are presented herein. COPD is diagnosed based on the presence of three major components: relevant exposure history, respiratory symptoms, and airway limitation that is not fully reversible. Clinical evaluation of patients diagnosed with COPD should include the level of symptoms, exacerbation rate, the presence of comorbidities and determination of phenotypes. The present abridged guideline is designed to be accessible and practical for assessing and managing patients with COPD. The application of up-to-date COPD guidelines may enhance the optimism of physicians and patients in managing this disease.

Biologic Treatments for Asthma and Chronic Obstructive Pulmonary Disorder

The global COVID-19 pandemic has brought respiratory disease to the forefront of public health, but asthma prevalence has been rising globally for decades. Asthma is mediated by errant immune activation and airway remodeling, but the influences of environment, nutrition, and comorbidities (e.g., asthma-chronic obstructive pulmonary disorder-overlap [ACO]) are still poorly understood. Even as a new generation of biologic-based treatments offer better airway control and reductions in mortality, a lack of prophylactic treatments and mechanistic understanding complicates efforts to prevent pathogenesis. This review will explicate and synthesize current knowledge on the effect of ACO and biologics (omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab) on pathogenesis, treatment, and prognosis.

Neurological and Psychiatric Comorbidities in Chronic Obstructive Pulmonary Disease

Background and Purpose

Chronic obstructive pulmonary disease (COPD) is often accompanied by different neurological and psychiatric comorbidities. The purpose of this study was to examine which of them are the most frequent and to explore whether their manifestation can be explained by underlying latent variables.

Methods

Data about patients with COPD and their neurological and psychiatric comorbidities were extracted from an electronic database of the National Health Insurance Fund of Lithuania for the period between January 1, 2012, and June 30, 2014. Exploratory factor analysis (EFA) was used to investigate comorbidity patterns.

Results

A study sample of 4834 patients with COPD was obtained from the database, 3338 (69.1%) of who were male. The most frequent neurological and psychiatric comorbidities were nerve, nerve root and plexus disorders (n=1439, 29.8%), sleep disorders (n=666, 13.8%), transient ischemic attack (n=545, 11.3%), depression (n=364, 7.5%) and ischemic stroke (n=349, 7.2%). The prevalence of ischemic stroke, transient ischemic attack, Parkinson’s disease, dementia and sleep disorders increased with age. One latent variable outlined during EFA grouped neurological disorders, namely ischemic stroke, transient ischemic attack, epilepsy, dementia and Parkinson’s disease. The second encompassed depression, anxiety, somatoform and sleep disorders. While similar patterns emerged in data from male patients, no clear comorbidity profiles among women with COPD were obtained.

Conclusion

Our study provides novel insights into the neurological and psychiatric comorbidities in COPD by outlining an association among cerebrovascular, neurodegenerative disorders and epilepsy, and psychiatric and sleep disorders. Future studies could substantiate the discrete pathological mechanism that underlie these comorbidity groups.

Impact of the COVID-19 pandemic on obstructive sleep apnea: recommendations for symptom management

STUDY OBJECTIVES

In the context of the current COVID-19 pandemic situation, we address the following important questions: (1) How can patients be identified for possible OSA while sleep clinic testing is temporarily unavailable or limited? and (2) What measures can be suggested to improve sleep health until proper diagnosis and treatment become safe and available again?

METHODS

As a proxy for home or in-laboratory testing, validation of a symptom-based measure of OSA risk is presented, based on an ongoing larger prospective study of 156 family medicine patients with OSA (88 women, 68 men; mean age, 57 years) and 60 control participants (36 women, 24 men; mean age, 54 years) recruited from the community. Participants completed the Sleep Symptom Checklist (SSC) and a range of other self-report measures; primary care patients also underwent a polysomnographic sleep study.

RESULTS

Results showed that (1) individuals with OSA reported more symptoms on the SSC related to insomnia, daytime symptoms, sleep disorders, and psychological maladjustment than did the control group (all P < .001), and (2) their sleep-related symptoms were significantly more severe than those of the control patients. In addition, several polysomnographic indices in recently diagnosed untreated individuals with OSA were significantly correlated with SSC measured sleep disorder symptoms, and SSC scores significantly distinguished participants with OSA from control participants.

CONCLUSIONS

Our findings suggest that family practitioners can effectively prescreen patients for possible OSA by inquiring about 5 items that form the SSC sleep disorders subscale. If OSA is suspected, then we can recommend a range of behavioral techniques to improve symptoms. The current pandemic causes us to reflect that the provisional targeting of symptoms and guidance regarding mitigation strategies while waiting for specialist care could serve patients well at any time.

Lung oxidative stress and transcriptional regulations induced by estradiol and intermittent hypoxia

We determined the effects of chronic intermittent hypoxia (CIH) and estradiol (E₂) on oxidative stress and gene expression in the lungs. Female Sprague-Dawley rats were left intact (sham) or ovariectomized (OVX) and implanted with pumps delivering vehicle or E₂ (0.5 mg/kg/day). Two weeks following surgery, the rats were exposed to room air (RA) or CIH for 7 days (10% O₂, 10 cycles/hour, 8 h/day). Lung samples were used to measure the activities of pro- (NADPH and xanthine oxidases) and antioxidant (superoxide dismutase, catalase and glutathione peroxidase) enzymes, and concentrations of advanced oxidation of protein products (AOPP). We determined gene expression with an RNA microarray and enrichment analysis of differentially expressed genes. In rats exposed to RA, OVX and E₂ supplementation increased pro- and antioxidant activities and AOPP concentration. In rats exposed to CIH, AOPP concentration, pro- and antioxidant enzymes activities increased in sham, did not changed in OVX-Veh rats, and were reduced in OVX-E₂ rats. In rats exposed to RA, genes involved in extracellular matrix were up-regulated by OVX and down-regulated by E₂, while E₂ up-regulated genes involved in cell mobility/adherence and leukocytes migration. OVX downregulated expression of roughly 200 olfactory receptor genes without effect of E₂. CIH altered gene expression in sham and OVX-E₂, but not in OVX-Veh rats. Enrichment analysis confirmed the antioxidant effects of E₂ under CIH. There are important interactions between ovarian hormones and CIH that can be relevant to better understand the consequences of sleep apnea (i.e. CIH) on the occurrence of lung pathologies in women.

Non-Contact Measurements of Electrocardiogram and Cough-Associated Electromyogram from the Neck Using In-Pillow Common Cloth Electrodes: A Proof-of-Concept Study

Asthma and chronic obstructive pulmonary disease are associated with nocturnal cough and changes in heart rate. In this work, the authors propose a proof-of-concept non-contact system for performing capacitive electrocardiogram (cECG) and cough-associated capacitive electromyogram (cEMG) measurements using cloth electrodes under a pillowcase. Two electrodes were located along with the approximate vector of lead II ECG and were used for both cECG and cEMG measurements. A signature voltage follower was introduced after each electrode to detect biopotentials with amplitudes of approximately 100 µV. A bootstrapping technique and nonlinear electrical component were combined and implemented in the voltage follower to attain a high input impedance and rapid static discharge. The measurement system was evaluated in a laboratory experiment for seven adult males and one female (average age: 22.5 ± 1.3 yr). The accuracy of R-wave detection for 2-min resting periods was 100% in six subjects, with an overall average of 87.5% ± 30.0%. Clearly visible cEMGs were obtained for each cough motion for all subjects, synchronized with reference EMGs from submental muscle. Although there remains room for improvement in practical use, the proposed system is promising for unobtrusive detection of heart rate and cough over a prolonged period of time.

Gender and Polysomnographic Profiles Findings in Obstructive Sleep Apnea Syndrome Patients Living in High Altitude

PURPOSE

Obstructive sleep apnea (OSA) is a common sleep disorder which prevalence is 22% in men and 17% in women. It is well described that females presented different clinical and polysomnographic characteristics compared with men. Those studies were performed in plain areas. We described the analysis by gender and clinical profiles of a sample of patients with diagnostic of OSA and living at high altitude.

PATIENTS AND METHODS

It is an observational study that describes differences between clinical and polysomnographic characteristics by gender in patients with OSA. Additionally, an unsupervised cluster algorithm was used to find groups of patients with similar clinical and polysomnographic characteristics.

RESULTS

We included 709 patients, 51.6% were females and 48.3% were males with mean age of 64 and 62 years old, respectively, in which 90.97% presented OSA. Men presented a higher apnea and hypopnea index than women (p=0.002), besides presented more sleep polysomnographic alterations. Meanwhile, women evidenced better sleep quality based on parameters. Additionally, in the sample of patients, we found four separated clinical profiles characterized mainly by differences in the severity of polysomnographic parameters.

CONCLUSION

The patients were more obese, older, and had lower SpO₂ values than most of those previously reported. Men had greater severity in most of the parameters measured by polysomnography. Polysomnographic variables were different both in the OSA patient profiles and in the gender comparison. However, the REM sleep apnea hypopnea index did not differ between sexes, indicating the importance of this variable in the evaluation of OSA severity in women. In contrast to previous reports, clinical and demographic characteristics showed few differences in both analyses. This result suggests that the behavior of OSA at high altitudes may have particularities with respect to low altitudes.

The deleterious effects of chronic obstructive pulmonary disease and obstructive sleep apnea: pathophysiology and implications on treatment

Background

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are both common in the adult population. The coexistence and association of both COPD and OSA have been described as the overlap syndrome. The scope of the present review is to address the magnitude, pathophysiology, clinical presentations, and the deleterious consequences of the coexistence of COPD and OSA in the same patient as well as the current management and treatment options of this association.

Main body of abstract

Epidemiological studies showed a prevalence of the overlap syndrome of up to 1% of the adult population. However, various studies agreed that this association is due to the fact that both COPD and OSA are common rather than an interaction of pathophysiology between the two affections. Nevertheless, sleep may cause adverse effects on breathing and lung functions. While these effects can be neglected in otherwise healthy individuals, they can lead in contrast to disastrous clinical outcomes particularly in vulnerable patients with the overlap syndrome leading to increased risk of cardiovascular diseases, acute COPD exacerbations, increased rates of hospitalizations, and nocturnal deaths. Current guidelines recommend polysomnography (PSG) as the gold standard investigation to diagnose sleep disorders and overlap syndrome. Treatment may include pulmonary rehabilitation, supplemental oxygen therapy, and non-invasive ventilation. Currently, continuous positive airway pressure (CPAP) therapy is the treatment of choice for the overlap syndrome. CPAP effects include improved respiratory mechanics; sleep quality, exercise tolerance, and prolonged survival.

Conclusion

Both COPD and OSA are common in the general population and present a significant risk of increased morbidity and mortality when they coexist in the same patient. Clinicians must carefully evaluate the clinical outcomes and the high risk of cardiovascular complications related to the overlap syndrome. Current data indicate that CPAP treatment leads to amelioration of the health-related quality of life and improve survival in patients with the overlap syndrome.

Dampness and mold at home and at work and onset of insomnia symptoms, snoring and excessive daytime sleepiness

AIM

To investigate whether exposure to dampness and mold at home and at work induce sleep disturbances and daytime sleepiness among adults.

MATERIALS AND METHODS

Associations between onset of sleep disturbances and dampness, mold and mold odor at home and at work were investigated in a cohort of 11,318 adults from the population in Iceland, Norway, Sweden, Denmark and Estonia. The participants answered a questionnaire at baseline and 10 years later, with questions on sleep disturbances, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), insomnia symptoms, snoring and excessive daytime sleepiness (EDS). Multiple logistic regression models were applied to estimate associations adjusting for potential confounders including gender, age, smoking habit at baseline, change of smoking habit from baseline to follow up, BMI at baseline, change of BMI from baseline to follow up, education level at follow up, allergic rhinitis at baseline, doctor diagnosed asthma at baseline and chronic bronchitis at baseline.

RESULTS

Baseline floor dampness, visible mold and mold odor at home increased onset of DIS, DMS, EMA, insomnia symptoms and snoring during follow up (OR 1.29-1.87). Any sign of dampness at baseline increased onset of DIS (OR 1.28, 95%CI 1.06-1.55), DMS (OR 1.17, 95%CI 1.02-1.34) and insomnia symptoms (OR 1.18, 95%CI 1.03-1.36). Dampness at home during follow up increased onset of DIS, DMS, EMA, insomnia symptoms and EDS (OR 1.17-1.36). Dampness at work during follow up increased onset of DIS, EMA, insomnia symptoms and EDS (OR 1.16-1.34). Combined dampness at home and at work during follow up increased the risk of onset of DIS, DMS, EMA, insomnia symptoms and EDS (OR 1.29-1.74).

CONCLUSIONS

Dampness and mold at home and at work can increase the development of insomnia symptoms, snoring and EDS among adults.

The Bronchiectasis in COPD-OSA Overlap Syndrome Patients

Purpose

COPD-OSA (chronic obstructive pulmonary disease–obstructive sleep apnea) overlap syndrome is associated with more frequent COPD acute exacerbations than COPD without OSA. With the application of high-resolution computed tomography (HRCT) in COPD, bronchiectasis is commonly detected and is associated with disease severity. Sleep respiratory disease is also associated with bronchiectasis; however, the correlation between OSA and coexisted bronchiectasis in COPD (COPD-Bx) has not been reported yet.

Patients and Methods

A total of 124 consecutive patients with stable COPD were enrolled. All subjects completed the chest HRCT and nocturnal polysomnography (PSG). The scores of extent and severity in bronchiectasis were assessed based on the Smith method and the Bhalla scoring system. Clinical data, questionnaire, routine blood test data, blood levels of C-reactive protein (CRP) and Immunoglobulin E, and the lymphocyte subtype were collected.

Results

Among all enrolled patients, 56.45% (70/124) were diagnosed as COPD-OSA based on the results of PSG screening. Bronchiectasis was detected in 42.86% (30/70) of the patients with COPD-OSA, but in 18.52% (10/54) of the patients without OSA (χ2=8.264, p=0.004). PSG screening revealed that COPD with OSA had a significantly higher apnea-hypopnea index and percent of time spent with oxygen saturation below 90% (T90). Higher values of CRP, T90, and lower CD4/CD8 in the COPD-Bx with OSA were detected compared to COPD-Bx without OSA. Correlation analysis showed that the Bhalla severity score was related to CD8 cell count (r=0.446, p<0.05) and CD4/CD8 (r=−0.357, p<0.05) in all the COPD-Bx patients. The Smith extent score was also associated with the values of CD8 count (r=0.388, p<0.05) and CD4/CD8 (r=−0.381, p<0.05).

Conclusion

The comorbid bronchiectasis was more common in COPD-OSA overlap syndrome patient and may be related to more severe hypoxia and increased systemic inflammation.

Evidence of Possible Irritable Larynx Syndrome in Obstructive Sleep Apnea: An Epidemiologic Approach

OBJECTIVE

"Irritable larynx syndrome" (ILS) often refers to a constellation of laryngeal-based symptoms including chronic cough (CC), diurnal dyspnea, and dysphonia. In patients with OSA, we examined: (1) the frequency, severity, comorbidity, risks and triggers of each problem, (2) whether these symptoms were compatible with stereotypic ILS and (3) the role of CPAP in their expression.

STUDY DESIGN

Cross-sectional, descriptive epidemiology study.

SETTING

Sleep-Wake Center at University of Utah Health Care, Salt Lake City, UT.

SUBJECTS AND METHODS

Ninety-four individuals with OSA (53 men, 41 women; mean age 54.7 ± 12.8 yrs.) underwent an extensive telephone interview that addressed study objectives.

RESULTS

Long-term CC, daytime breathing and voice problems were common, especially among women despite less severe OSA. Women, more than men, reported all three chronic conditions alone or in combination: CC (44% vs 11.3%), diurnal dyspnea (41.5% vs 13.2%) and voice disorders (41.5% vs 13.2%). Symptoms were not associated with age, BMI or Apnea Hypopnea Index after adjusting for sex. Although evidence supporting stereotypic ILS symptomatology was inconsistent, those participants with a voice disorder were 3.3 (95% CI = 1.8-6.0) times more likely to report CC and 2.4 (95% CI = 1.3-4.4) times more likely to experience diurnal dyspnea. Esophageal reflux, post-nasal drip, and frequent sinus infections were significantly associated with all three conditions. Triggers that provoked or made symptoms worse varied by condition and sex. Nightly, humidified CPAP use was associated with fewer symptoms overall and improved quality of life.

CONCLUSIONS

Symptoms suggestive of possible ILS are common in OSA, especially among women, and lessened by nightly CPAP use.

Effects of inhaled fluticasone propionate on extrinsic tongue muscles in rats

Obstructive sleep apnea (OSA) is more common in patients with asthma, and inhaled corticosteroids may contribute to OSA pathogenesis in these patients. This study tested the effects of orally inhaled fluticasone propionate (FP) on extrinsic tongue muscles. Unanesthetized rats were treated with FP or placebo for 28 days. On day 29, tongue retrusive and protrusive functions were tested via hypoglossal nerve stimulation under a state of anesthesia, followed by genioglossus (GG), styloglossus (SG) and hyoglossus (HG) muscle extraction, after euthanasia, for histology [myosin heavy chain (MHC) fibers and laminin content reflecting extracellular matrix (ECM)]. On protrusive testing, FP increased percent maximum tetanic force at 40 Hz (P = 0.03 vs. placebo) and endurance index (P = 0.029 vs. placebo). On retrusive testing, FP increased maximum twitch (P = 0.026 vs. placebo) and tetanic forces (P = 0.02 vs. placebo) with no effect on endurance index. On histology, FP increased GG cross-sectional area of MHC type IIa (P = 0.036 vs. placebo) and tended to increase type IIb (P = 0.057 vs. placebo) fibers and HG MHC IIx fibers (P = 0.065). The FP group had significantly increased laminin-stained areas, of greatest magnitude in the HG muscle. FP affects tongue protrusive and retrusive functions differently, concurrent with a shift in MHC fibers and increased ECM accumulation. These differential alterations may destabilize the tongue's "muscle hydrostat" during sleep and promote collapse.NEW & NOTEWORTHY The effects of inhaled corticosteroid on upper airway may contribute to OSA pathogenesis in asthma. In this study, we tested the effects of orally inhaled fluticasone propionate on tongue protrusive and retrusive functions and on tongue extrinsic muscle fiber composition and molecular properties. We found that fluticasone treatment: 1) increased protrusive endurance and retrusive maximum twitch and tetanic force; and 2) on histology, increased cross-sectional area of myosin heavy chain (MHC) type IIa fibers and tended to increase cross-sectional area of MHC type IIb fibers in the protrusive muscle and of MHC IIx fibers in the retrusors. It also increased laminin-stained areas, across extrinsic tongue muscles, of greatest magnitude in the retrusors; and 3) reduced protein degradation and activated pathways associated with increased protein synthesis in the protrusor. These differential effects on the protrusors and retrusors may destabilize the tongue's "muscle hydrostat" properties during sleep and promote collapse.

Phenotypic Subtypes of OSA: A Challenge and Opportunity for Precision Medicine

Current strategies for the management of OSA reflect a one-size-fits-all approach. Diagnosis and severity of OSA are based on the apnea-hypopnea index and treatment initiated with CPAP, followed by trials of alternatives (eg, oral appliances) if CPAP "fails." This approach does not consider the heterogeneity of individuals with OSA, reflected by varying risk factors, pathophysiological causes, clinical manifestations, and consequences. Recently, studies using analytic approaches such as cluster analysis have taken advantage of this heterogeneity to identify OSA phenotypes, or subtypes of patients with unique characteristics, that may enable more personalized approaches to prognostication and treatment. Examples include symptom-based subtypes such as "excessively sleepy" and "disturbed sleep" with differing impact of CPAP on symptoms and health-related quality of life. Polysomnographic subtypes, distinguished by respiratory event association with hypoxemia, arousals, or both, exhibit varying risks of cardiovascular disease and response to therapy. This review summarizes the findings from recent cluster analysis studies in sleep apnea and synthesizes common themes to describe the potential role (and limitations) of phenotypic subtypes in precision medicine for OSA. It also highlights future directions, including linking of phenotypes to clinically relevant outcomes, rigorous and transparent assessment of phenotype reproducibility, and need for tools that categorize patients into subtypes, to prospectively validate phenotype-based prognostication and treatment approaches. Finally, we highlight the critical need to include women and more racially/ethnically diverse populations in this area of research if we are to leverage the heterogeneity of OSA to improve patient lives.

Obstructive Lung Disease and Obstructive Sleep Apnea (OLDOSA) cohort study: 10-year assessment

STUDY OBJECTIVES

Asthma, chronic obstructive pulmonary disease (COPD), and obstructive sleep apnea (OSA) are very prevalent disorders. Their coexistence in the same individual has an unclear effect on natural history and long-term outcomes.

METHODS

The OLDOSA (Obstructive Lung Disease and Obstructive Sleep Apnea) cohort enrolled 4,980 veterans with an acute hospitalization and in whom asthma, COPD, OSA, overlapping conditions, or none of these disorders at baseline had been diagnosed. Pulmonary function, polysomnography, positive airway pressure (PAP) recommendations and adherence, and vital status were collected and analyzed. Various proportional hazards models were built for patients with OSA to test the effect of PAP therapy on survival.

RESULTS

Ten-year all-cause cumulative mortality rate was 52.8%; median time to death was 2.7 years. In nonoverlapping asthma, OSA and COPD, mortality rates were 54.2%, 60.4%, and 63.0%, respectively. The overlap syndromes had the following mortality: COPD-OSA 53.2%, asthma-COPD 62.1%, asthma-OSA 63.5%, and triple overlap asthma-COPD-OSA 67.8%. In patients with OSA not on PAP therapy, after adjustment for age, comorbidities, and lung function, risk of death was 1.34 (1.05-1.71) times higher than those undergoing treatment. Similarly, in patients with OSA nonadherent to PAP therapy the adjusted risk of death was 1.78 (1.13-2.82) times higher versus those using it at least 70% of nights and more than 4 hours nightly.

CONCLUSIONS

In this large longitudinal cohort of hospitalized veterans with high comorbid burden, asthma, COPD, OSA and their overlap syndromes had very high long-term mortality. In patients with OSA, PAP initiation and superior therapeutic adherence were associated with significantly better survival.

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.

A Wake-up Call for Human Immunodeficiency Virus (HIV) Providers: Obstructive Sleep Apnea in People Living With HIV

Obstructive sleep apnea (OSA) is defined by repetitive collapse of the upper airway during sleep leading to transient hypoxemia and arousals from sleep. Surges in sympathetic activity, repeated oxygen desaturation, and sleep fragmentation can lead to cardiovascular (eg, myocardial infarction) and neurocognitive (eg, excessive daytime sleepiness) consequences. Emerging data suggest that OSA is common in people living with human immunodeficiency virus (PLWH) and that traditional risk factors for OSA, such as obesity, are not highly predictive of OSA in PLWH. Untreated OSA is associated with increased fatigue and levels of inflammation. Despite these data, most PLWH with OSA remain undiagnosed and untreated. Improved awareness of OSA among healthcare providers and greater use of OSA diagnostic approaches have the potential to substantially improve quality of life and outcomes in PLWH.

Sleep Pharmacotherapy for Common Sleep Disorders in Pregnancy and Lactation

Sleep disturbances are common in pregnancy, and sleep disorders may worsen or present de novo in the course of gestation. Managing a pregnant patient is complicated by the risk of teratogenicity, pharmacokinetic changes, and the dynamic nature of pregnancy. Although nonpharmacologic interventions are likely safest, they are often ineffective, and a patient is left dealing with frustrations of the sleep disturbance, as well as the negative outcomes of poor sleep in pregnancy. As with any other condition in pregnancy, management requires an understanding of pregnancy physiology, knowledge of the impact of a given condition on pregnancy or fetal and neonatal outcomes, and an ability to weigh the risk of the exposure to an untreated, or poorly treated condition, against the risk of a given drug. In partnership with the pregnant patient or couple, options for therapy should be reviewed in the context of the impact of the condition on pregnancy and offspring outcomes, while understanding that data (positive or negative) on the impact of therapy on perinatal outcomes are lacking. This article reviews the epidemiology of sleep disorders in pregnancy, general principles of prescribing in pregnancy and lactation, and safety surrounding therapeutic options in pregnancy.

Prevalence and clinical impact of snoring in older community-dwelling adults

AIM

The prevalence and clinical impact of snoring in the independent older adult population is unknown. To address this, we carried out this cross-sectional epidemiological study of community-dwelling independent older adults.

METHODS

The study data were collected by the Japan Gerontological Evaluation Study 2013, a postal survey distributed to a large cohort of independent community-dwelling older adults (aged ≥65 years) in 2013, across 30 municipalities of 14 prefectures. We used data for 24 837 participants (13 135 women, mean age 73.5 years, and 11 702 men, mean age 73.3 years). The association of snoring with airway symptoms and history of hypertension, diabetes and heart disease were investigated using Poisson regression models.

RESULTS

The prevalence ratio (95% confidence intervals) for wheezing according to snoring frequency in men was 1.87 (1.45-2.43) among those who snored on 1-6 nights a week, and 2.95 (2.15-4.05) among those who snored every night. Similar relationships were observed for women. Expectoration, another airway symptom, was also associated with snoring frequency. Furthermore, snoring frequency was associated with a higher prevalence of hypertension, diabetes and heart disease. Both diabetes and heart disease were associated with snoring frequency in women independent of body mass index, but the association was only observed in men with a normal or lower body mass index.

CONCLUSIONS

Snoring is a highly prevalent and pathogenic symptom in adults aged ≥65 years. Geriatr Gerontol Int 2019; 19: 1165-1171.

Sleep in chronic respiratory disease: COPD and hypoventilation disorders

COPD and obstructive sleep apnoea (OSA) are highly prevalent and different clinical COPD phenotypes that influence the likelihood of comorbid OSA. The increased lung volumes and low body mass index (BMI) associated with the predominant emphysema phenotype protects against OSA whereas the peripheral oedema and higher BMI often associated with the predominant chronic bronchitis phenotype promote OSA. The diagnosis of OSA in COPD patients requires clinical awareness and screening questionnaires which may help identify patients for overnight study. Management of OSA-COPD overlap patients differs from COPD alone and the survival of overlap patients treated with nocturnal positive airway pressure is superior to those untreated. Sleep-related hypoventilation is common in neuromuscular disease and skeletal disorders because of the effects of normal sleep on ventilation and additional challenges imposed by the underlying disorders. Hypoventilation is first seen during rapid eye movement (REM) sleep before progressing to involve non-REM sleep and wakefulness. Clinical presentation is nonspecific and daytime respiratory function measures poorly predict nocturnal hypoventilation. Monitoring of respiration and carbon dioxide levels during sleep should be incorporated in the evaluation of high-risk patient populations and treatment with noninvasive ventilation improves outcomes.

IL-33 Mediated Inflammation in Chronic Respiratory Diseases-Understanding the Role of the Member of IL-1 Superfamily

Interleukin 33 (IL-33) is an alarmin cytokine from the IL-1 family. IL-33 is localized in the nucleus and acts there as a gene regulator. Following injury, stress or cell death, it is released from the nucleus, and exerts its pro-inflammatory biological functions via the transmembrane form of the ST2 receptor, which is present mainly as attached to immune cells. In recent years, IL-33 became a focus of many studies due to its possible role in inflammatory disorders. Among respiratory disorders, the contribution of IL-33 to the development of asthma, in particular, has been most identified. Increased level of IL-33 in lung epithelial cells and blood serum has been observed in asthma patients. The IL-33/ST2 interaction activated the Th2 mediated immune response and further production of many pro-inflammatory cytokines. Single nucleotide polymorphisms in the IL-33 gene cause a predisposition to the development of asthma. Similarly, in chronic pulmonary obstructive disease (COPD), both increased expression of IL-33 and the ST2 receptor has been observed. Interestingly, cigarette smoke, a key inducer of COPD, not only activates IL-33 production by epithelial and endothelial cells, but also induces the expression of IL-33 in peripheral blood mononuclear cells. Knowledge regarding its contribution in other respiratory disorders, such as obstructive sleep apnea, remains greatly limited. Recently it was shown that IL-33 is one of the inflammatory mediators by which levels in blood serum are increased in OSA patients, compared to healthy control patients. This mini review summarizes current knowledge on IL-33 involvement in chosen chronic respiratory disorders and proposes this interleukin as a possible link in the pathogenesis of these diseases.

Polysomnographic variables in Alternate overlap syndrome: data from sleep heart health study

Objective: To evaluate influence of asthma on polysomnographic variables of patients with obstructive sleep apnea (OSA).Methods: A longitudinal retrospective study using data collected from the Sleep Heart Health Study (SHHS).Results: All 2822 patients included had OSA, 2599 were non-asthmatic whereas 223 were asthmatics. Average BMI for non-asthmatics was 28.8 kg/m² whereas asthmatics had 29.5 kg/m². Median pack-years of smoking was 1.42 vs. 1.98 in non-asthmatic and asthmatic groups, respectively. Sex distribution, age (in years), BMI, FEV₁, FVC, AHI ≥ 4% (all apneas, hypopneas with ≥4% oxygen desaturation or arousal per hour of sleep), RDI ≥ 3% (overall respiratory distribution index at ≥3% oxygen desaturation or arousal), sleep latency, percentage of sleep time in apnea/hypopnea and Epworth sleep scale score were all statistically significant. Non-asthmatics had greater AHI (12.63/hr) compared to asthmatics (11.34/hour), p = 0.0015. RDI in non-asthmatics and asthmatics was (23.07 vs 20.53; p = 0.009). Sleep latency was found to be longer in asthmatics 19.8 minutes vs. 16 minutes (p = 0.008). Epworth sleepiness scale score was high in asthmatics (9 vs. 8, p = 0.002).Conclusion: OSA was found more severe in non-asthmatic subgroup, but asthmatics had statistically significant higher Epworth sleepiness scale score and sleep latency. Clinicians should be vigilant and keep low threshold to rule out OSA particularly on patients with difficult to control asthma, smoker, GERD, obese and nasal disease.

Associations of variants In the hexokinase 1 and interleukin 18 receptor regions with oxyhemoglobin saturation during sleep

Sleep disordered breathing (SDB)-related overnight hypoxemia is associated with cardiometabolic disease and other comorbidities. Understanding the genetic bases for variations in nocturnal hypoxemia may help understand mechanisms influencing oxygenation and SDB-related mortality. We conducted genome-wide association tests across 10 cohorts and 4 populations to identify genetic variants associated with three correlated measures of overnight oxyhemoglobin saturation: average and minimum oxyhemoglobin saturation during sleep and the percent of sleep with oxyhemoglobin saturation under 90%. The discovery sample consisted of 8,326 individuals. Variants with p < 1 × 10(-6) were analyzed in a replication group of 14,410 individuals. We identified 3 significantly associated regions, including 2 regions in multi-ethnic analyses (2q12, 10q22). SNPs in the 2q12 region associated with minimum SpO2 (rs78136548 p = 2.70 × 10(-10)). SNPs at 10q22 were associated with all three traits including average SpO2 (rs72805692 p = 4.58 × 10(-8)). SNPs in both regions were associated in over 20,000 individuals and are supported by prior associations or functional evidence. Four additional significant regions were detected in secondary sex-stratified and combined discovery and replication analyses, including a region overlapping Reelin, a known marker of respiratory complex neurons.These are the first genome-wide significant findings reported for oxyhemoglobin saturation during sleep, a phenotype of high clinical interest. Our replicated associations with HK1 and IL18R1 suggest that variants in inflammatory pathways, such as the biologically-plausible NLRP3 inflammasome, may contribute to nocturnal hypoxemia.

Impact of PAP therapy on hospitalization rates in Medicare beneficiaries with COPD and coexisting OSA

OBJECTIVE

Growing evidence supports that patients with chronic obstructive pulmonary disease (COPD) and coexisting obstructive sleep apnea (OSA) have poor prognosis. This association is described as overlap syndrome. Positive airway pressure (PAP) therapy is now the preferred treatment for OSA. We hypothesized that use of PAP therapy in elderly patients with overlap syndrome would be associated with lower healthcare utilization.

METHODS

In this retrospective cohort study, we analyzed data from 5% national sample of fee-for-service Medicare beneficiaries with a diagnosis of COPD who were newly started on PAP therapy in 2011. We examined the effect of PAP therapy on emergency room (ER) visits and hospitalizations for all-cause and COPD-related conditions in the 1 year pre- and 1 year post-initiation of PAP therapy.

RESULTS

In year 2011, we identified 319 patients with overlap syndrome who were new users of PAP therapy. In this cohort of patients, hospitalization rates for COPD-related conditions were significantly lower in the 1 year post-initiation of PAP therapy compared to the 1-year pre-initiation period (19.4 vs 25.4%, P value = 0.03). However, ER visits (for any cause or COPD-related conditions) and hospitalization rates for any cause did not differ significantly in the pre- and post-initiation periods. PAP therapy was more beneficial in older adults, those with higher COPD complexity, and those with three or more comorbidities.

CONCLUSION

Initiation of PAP therapy in elderly patients with overlap syndrome is associated with a reduction in hospitalization for COPD-related conditions, but not for all-cause hospitalizations and ER visits.

Polysomnographic features of low arousal threshold in overlap syndrome involving obstructive sleep apnea and chronic obstructive pulmonary disease

PURPOSE

In patients with overlap syndrome (OVS), the pathophysiologies of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease can interact with one another. Focusing on low arousal threshold, the authors evaluated polysomnographic features of OVS patients.

METHODS

This retrospective, multicenter study was conducted at three hospitals in Japan. Patients aged ≥ 60 years who underwent polysomnography and pulmonary function testing were reviewed. Severity of airflow limitation (AFL) was classified according to the Global Initiative for Chronic Obstructive Lung Disease criteria. Low arousal threshold was predicted based on the following polysomnography features: lower apnea-hypopnea index (AHI); higher nadir oxygen saturation, and larger hypopnea fraction of total respiratory events. These features were compared among patients with only OSA (n = 126), OVS with mild AFL (n = 16), and OVS with moderate/severe AFL (n = 22).

RESULTS

A low arousal threshold was more frequently exhibited by OVS patients with moderate/severe AFL than by those with OSA only (p = 0.016) and OVS with mild AFL (p = 0.026). As forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) decreased in OVS patients, the mean length of apnea decreased (r = 0.388, p = 0.016), hypopnea fractions increased (r = - 0.337, p = 0.039), and AHI decreased (r = 0.424, p = 0.008). FEV₁/FVC contributed to low arousal threshold independent of age, sex, smoking history, hospital, or body mass index in all subjects (OR 0.946 [95% CI 0.909-0.984]) and in OVS patients (OR 0.799 [95% CI 0.679-0.940]).

CONCLUSIONS

This study first described peculiar polysomnographic features in OVS patients with moderate/severe AFL, suggesting a high prevalence of low arousal threshold.

Poor Outcomes Among Patients With Chronic Obstructive Pulmonary Disease With Higher Risk for Undiagnosed Obstructive Sleep Apnea in the LOTT Cohort

STUDY OBJECTIVES

Evaluate consequences of intermediate to high risk of undiagnosed obstructive sleep apnea (OSA) among individuals with chronic obstructive pulmonary disease (COPD).

METHODS

Using data from the Long Term Oxygen Treatment Trial (LOTT), we assessed OSA risk at study entry among patients with COPD. We compared outcomes among those at intermediate to high risk (modified STOP-BANG score ≥ 3) relative to low risk (score < 3) for OSA. We compared risk of mortality or first hospitalization with proportional hazard models, and incidence of COPD exacerbations using negative binomial regression. We adjusted analyses for demographics, body mass index, and comorbidities. Last, we compared St. George Respiratory Questionnaire and Quality of Well-Being Scale results between OSA risk groups.

RESULTS

Of the 222 participants studied, 164 (74%) were at intermediate to high risk for OSA based on the modified STOP-BANG score. Relative to the 58 low-risk individuals, the adjusted hazard ratio of mortality or first hospitalization was 1.61 (95% confidence interval 1.01-2.58) for those at intermediate to high risk of OSA. Risk for OSA was also associated with increased frequency of COPD exacerbations (adjusted incidence rate ratio: 1.78, 95% confidence interval 1.10-2.89). Respiratory symptoms by St. George Respiratory Questionnaire were 5.5 points greater (P = .05), and Quality of Well-Being Scale scores were .05 points lower (P < .01) among those at intermediate to high risk for OSA, indicating more severe respiratory symptoms and lower quality of life.

CONCLUSIONS

Among individuals with COPD, greater risk for undiagnosed OSA is associated with poor outcomes. Increased recognition and management of OSA in this group could improve outcomes.

Differentiation of adult severe asthma from difficult-to-treat asthma - Outcomes of a systematic assessment protocol

BACKGROUND

Guidelines recommend a differentiation of difficult-to-treat asthma from severe asthma. However, this might be complex and to which extent this distinction is achievable in clinical practice remains unknown.

OBJECTIVE

To evaluate to which degree a systematic evaluation protocol enables a differentiation between severe versus difficult-to-treat asthma in patients in specialist care on high intensity asthma treatment, i.e. potentially severe asthma.

METHODS

All adult asthma patients seen in four respiratory clinics over one year were screened prospectively for asthma severity. Patients with difficult-to-control asthma according to ERS/ATS criteria (high-dose inhaled corticosteroids/oral corticosteroids) underwent systematic assessment to differentiate severe asthma patients from those with other causes of poor asthma control: objective confirmation of the asthma diagnosis as well as assessment of treatment barriers and comorbidities.

RESULTS

Overall, 1034 asthma patients were screened, of whom 175 (16.9%) had difficult-to-control asthma. 117 of these accepted inclusion, and completed systematic assessment. Asthma diagnosis was objectively confirmed in 88%. Sub-optimal adherence (42.5%), inhaler errors (31.5%) and unmanaged comorbidities (66.7%) were common. After primary assessment, 12% (14/117) fulfilled strict criteria for severe asthma. Moreover, 56% (66/117) were instantly classified as difficult-to-treat asthma due to poor adherence/inhaler technique. Finally, an ´overlap' group of 32% (37/117) were identified with patients being adherent and displaying correct inhaler technique, but had unmanaged comorbidities -potentially fitting into both the difficult-to-treat and severe group.

CONCLUSION

Only a minority of patients with difficult-to-control asthma were found to have severe asthma after primary systematic assessment. Nevertheless, strict categorisation of severe vs. difficult-to-treat asthma seems to pose a challenge.