A review of therapies for the overlap syndrome of obstructive sleep apnea and chronic obstructive pulmonary disease

Association between lung function and sleep disorder symptoms in a community-based multi-site case-finding study

Obstructive airway disease is associated with sleep disturbances. We aimed to assess the relationship between lung function and sleep disorder symptoms using cross-sectionally collected data between March 2017 and August 2021 from the Undiagnosed Chronic Obstructive Pulmonary Disease and Asthma Population study, a prospective community-based multi-site case-finding study. Undiagnosed Chronic Obstructive Pulmonary Disease and Asthma Population study participants with respiratory symptoms but without diagnosed lung disease who completed spirometry and the Global Sleep Assessment Questionnaire were included. We conducted multivariate linear regression models for forced expiratory volume in 1 s, forced vital capacity and forced expiratory volume in 1 s/forced vital capacity by Global Sleep Assessment Questionnaire responses adjusted for confounders. The same models were employed to examine respiratory symptoms, as reported on the St George's Respiratory Questionnaire and Chronic Obstructive Pulmonary Disease Assessment Test, by Global Sleep Assessment Questionnaire responses. Logistic regression models were used to assess the association of undiagnosed obstructive airway disease with sleep symptoms. Amongst 2093 adults included in the study, 48.3% were female and the median age was 63 years (interquartile range 53-72). Two-hundred and five (9.79%) subjects met spirometry criteria for undiagnosed chronic obstructive pulmonary disease, and 191 (9.13%) for undiagnosed asthma. There were no significant associations between spirometry measures and sleep symptoms (p > 0.5), controlling for age, sex, body mass index, smoking and comorbidities. Those with undiagnosed asthma were more likely to report insomnia "at least sometimes" versus "never" (odds ratio 2.58, 95% confidence interval: 1.27-6.19, p = 0.02). Respiratory symptoms were associated with sleep symptoms, with significant (p < 0.05) increases in St George's Respiratory Questionnaire and Chronic Obstructive Pulmonary Disease Assessment Test scores in those reporting most sleep symptoms. Overall, we found an association between undiagnosed asthma and insomnia, and between respiratory and sleep disorder symptoms.

Diagnosis and management of comorbid disease in COPD

COPD is one of the most common chronic respiratory conditions and is associated with high healthcare use, morbidity and mortality. Multimorbidity in COPD is common and confers a worse prognosis. Despite this, there is delayed and often under-diagnosis of comorbid diseases in COPD. Knowledge of the respiratory and non-respiratory pathologies that can coexist with COPD is essential to ensure early detection and appropriate management. This review provides an overview of the comorbidities that have been described in COPD. We discuss their pathogenesis, pitfalls in their diagnosis, and strategies for their prevention and treatment.

COPD overlap conditions: Clinical and therapeutic implications

Chronic Obstructive Pulmonary Disease (COPD) is a complex pulmonary condition characterized by chronic airflow limitation. Within the spectrum of COPD, distinct overlap conditions exist, including Asthma-COPD Overlap (ACO), COPD-Obstructive Sleep Apnea (COPD-OSA), Combined Pulmonary Fibrosis and Emphysema (CPFE), and Bronchiectasis-COPD Overlap (BCO). This review provides a comprehensive overview of the clinical and therapeutic implications of these conditions, highlighting the differences in complications compared with COPD alone in addition to the diagnostic challenges of identifying these conditions. Therapeutically tailored approaches are necessary for COPD overlap conditions considering the unique complications that may arise. Optimal pharmacological management, disease-specific interventions, and comprehensive patient-centered care are crucial components of treatment strategies. This review provides insights for healthcare professionals by enhancing their understanding and management of these conditions. This emphasizes the importance of accurate diagnosis and individualized treatment plans, considering the specific complications associated with each COPD overlap condition.

Defining a phenotype of severe COPD patients who develop chronic hypercapnia

INTRODUCTION

Chronic hypercapnia, defined by elevated blood CO2 levels, is a serious complication most prevalent in severe COPD. It negatively impacts quality of life, increases hospitalization rates, and elevates mortality risks. However, not all severe COPD patients develop chronic hypercapnia, and its underlying mechanisms remain unclear. Identifying clinical and pathophysiological predictors of hypercapnia is essential for tailored treatment strategies. This study investigates the relationship between hypercapnia and patient characteristics, lung function, and CT scan features to identify potential therapeutic targets.

METHODS

This cross-sectional study included 1526 COPD patients from three cohorts: a standard care cohort and two research cohorts (NCT04023409; NCT03053973). Data collected included demographic and clinical information, blood gases, lung function (FEV1, FVC, TLC, RV, DLCOc), and high-resolution CT scans (lung volumes, air trapping, emphysema scores, airway wall thickness (Pi10), and diaphragm indices).

RESULTS

Hypercapnia prevalence increased with COPD severity. Hypercapnic patients were older, more likely to smoke, and had more comorbidities. They exhibited lower FEV1 and FVC, and higher RV/TLC ratios, with CT scans showing lower emphysema scores and greater Pi10. Multivariate analysis identified lower PaO2, FEV1% predicted, and emphysema scores, along with higher RV/TLC ratios and NT-proBNP levels, as independent predictors of PaCO2, collectively explaining 46.3 % of the variance.

CONCLUSION

COPD patients with chronic hypercapnia are characterized by higher smoking rates, lower PaO2 levels, poorer lung function, less emphysema, and increased airway pathology. These findings underscore the multifactorial nature of hypercapnia in COPD, highlighting the need for personalized therapeutic strategies targeting these factors to improve outcomes.

Insights into the Overlap of Chronic Obstructive Pulmonary Disease and Sleep Apnea: Experience from the Clinic of Pneumology, Târgu Mureș

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) has a severe impact on patients' health and can lead to multiple complications.

MATERIAL AND METHODS

We analyzed the co-occurrence of obstructive sleep apnea (OSA) in COPD patients hospitalized in the Pneumology Clinic of Târgu Mureș, Romania.

RESULTS

A total of 150 COPD patients were investigated by clinical examination, STOP-BANG and Epworth questionnaires, ventilatory polygraphy (PG), EKG, cardiac ultrasound, blood lipids, and sugar. Sixty-eight patients (45.3%) had OSA associated with COPD. A total of 61.7% were COPD gr. E, and 30.8% were gr. B. Frequently shown symptoms were snoring and nonrestorative sleep (100%), somnolence (73.5%), nocturnal awakenings (41.17%), morning headache (32.3%), and aggravated dyspnea. Types of OSA included obstructive (97.05%), central (2.5%), and associated obesity-hypoventilation (39.7%). A total of 76.4% were recently diagnosed with OSA. Men predominated at 70.5%, 76.4% were smokers, and 61.7% had experienced alcohol abuse. A total of 25% were overweight, and 71% had obesity. A total of 13.2% belonged to the category of 38-50-year-olds, 55.8% were in the 51-65-year-old category, 17.6% were in the 66-70-year-old category, and roughly 13.2% were in the 71-year-old category. Overlap syndrome (OS) comorbidities and complications were frequently present: 41% experienced respiratory failure, 66.1% experienced blood hypertension, 58.8% experienced ischemic cardiac disease, 32.35% experienced diabetes mellitus, 50% experienced dyslipidemia, and 29.4% experienced cor pulmonale.

CONCLUSIONS

OS conferred gravity or directly contributed to cardiovascular, respiratory, and metabolic complications. OS was associated with more severe COPD and obesity. The prevalence of smoking in OS patients was higher than the national/European average.

Dyspnea and Quality of Life Improvements with Management of Comorbid Obstructive Sleep Apnea in Chronic Lung Disease

Obstructive sleep apnea (OSA) has emerged as a significant and prevalent comorbidity associated with chronic lung diseases, including chronic obstructive pulmonary disease, asthma, and interstitial lung diseases. These overlap syndromes are associated with worse patient-reported outcomes (sleep quality, quality of life measures, mental health) than each condition independently. Observational studies suggest that patients with overlap syndrome who are adherent to positive airway pressure therapy report improved quality of life, sleep quality, depression, and daytime symptoms. Screening for and management of OSA in patients with overlap syndrome should emphasize the interconnected nature of these 2 conditions and the positive impact that OSA management can have on patients' well-being and overall health.

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.

Comorbidities in COPD: Current and Future Treatment Challenges

Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung condition, primarily characterized by the presence of a limited airflow, due to abnormalities of the airways and/or alveoli, that often coexists with other chronic diseases such as lung cancer, cardiovascular diseases, and metabolic disorders. Comorbidities are known to pose a challenge in the assessment and effective management of COPD and are also acknowledged to have an important health and economic burden. Local and systemic inflammation have been proposed as having a potential role in explaining the association between COPD and these comorbidities. Considering that the number of patients with COPD is expected to rise, understanding the mechanisms linking COPD with its comorbidities may help to identify new targets for therapeutic purposes based on multi-dimensional assessments.

Comments on "Comparison of immediate withdrawal and stepwise reduction in duration of non-invasive ventilation in chronic obstructive pulmonary disease patients presenting with acute hypercapnic respiratory failure"

Dear Editor,  The recent study published by Purohit et al. provides new evidence on the safety of immediate withdrawal of non-invasive ventilation in chronic obstructive pulmonary disease patients admitted with acute hypercapnic respiratory failure after recovery...

Nocturnal nasal high-flow oxygen therapy in elderly patients with concomitant chronic obstructive pulmonary disease and obstructive sleep apnea

PURPOSE

The coexistence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) is known as "overlap syndrome" (OS). Patients with OS are usually older than patients with OSA alone, suffer from more profound oxygen desaturation during the obstructive events often accompanied by sustained nocturnal hypoventilation. Although oxygen-enriched positive airway pressure (PAP) is the treatment of choice in these patients, this therapy is often poorly tolerated particularly by the elderly. The aim of this study was to assess the usefulness of nocturnal oxygen therapy via nasal high flow (NHF-OT) as a possible alternative to PAP in patients with OS.

METHODS

Patients > 65 years old with OS and nocturnal respiratory failure (time spent below SaO2 90% (T90) > 30%) had cardio-respiratory monitoring performed at baseline, during NHF-OT, or during conventional oxygen therapy (COT).

RESULTS

A total of 40 patients were enrolled in the study. NHF-OT significantly reduced the apnea-hypopnea index (AHI) in all patients compared to baseline and COT. The mean basal AHI was 25.4 ± 8.6. During COT and NHF-OT, the AHI was 19.4 ± 7 and 5.4 ± 4.6, respectively (P < 0.001) and 19 patients reached an AHI < 5 during NHF-OT. The mean nocturnal SaO2% was 86.2 ± 2.6 at baseline and at equivalent FiO2 it significantly increased to 91.8 ± 2.4 during COT and to 93.9 ± 2.5 during NHF-OT (P < 0.001). The T90% was 48.7 ± 20.1 at baseline, 16.8 ± 11.7 during COT, and 8.8 ± 8.0 during NHF-OT (P < 0.001).

CONCLUSIONS

In elderly patients with OS, nocturnal treatment with NHF-OT significantly reduces obstructive episodes and improves oxygenation. As the treatment is generally well tolerated compared to PAP, NHF-OT may be a possible alternative therapy in this subgroup of patients.

A risk-predictive model for obstructive sleep apnea in patients with chronic obstructive pulmonary disease

Background

Obstructive sleep apnea syndrome (OSA) is increasingly reported in patients with chronic obstructive pulmonary disease (COPD). Our research aimed to analyze the clinical characteristics of patients with overlap syndrome (OS) and develop a nomogram for predicting OSA in patients with COPD.

Methods

We retroactively collected data on 330 patients with COPD treated at Wuhan Union Hospital (Wuhan, China) from March 2017 to March 2022. Multivariate logistic regression was used to select predictors applied to develop a simple nomogram. The area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA) were used to assess the value of the model.

Results

A total of 330 consecutive patients with COPD were enrolled in this study, with 96 patients (29.1%) confirmed with OSA. Patients were randomly divided into the training group (70%, n = 230) and the validation group (30%, n = 100). Age [odds ratio (OR): 1.062, 1.003–1.124], type 2 diabetes (OR: 3.166, 1.263–7.939), neck circumference (NC) (OR: 1.370, 1.098–1,709), modified Medical Research Council (mMRC) dyspnea scale (OR: 0.503, 0.325–0.777), Sleep Apnea Clinical Score (SACS) (OR: 1.083, 1.004–1.168), and C-reactive protein (CRP) (OR: 0.977, 0.962–0.993) were identified as valuable predictors used for developing a nomogram. The prediction model performed good discrimination [AUC: 0.928, 95% confidence interval (CI): 0.873–0.984] and calibration in the validation group. The DCA showed excellent clinical practicability.

Conclusion

We established a concise and practical nomogram that will benefit the advanced diagnosis of OSA in patients with COPD.

[Long-term stenting as an option to ensure the stability of the respiratory tract in a patient with rhonchopathy and overlap syndrome]

Rhonchopathy is a major problem of both a medical and social nature, it is detected in about 33% of the adult population. It should be noted that snoring is often accompanied by a more formidable disease - obstructive sleep apnea (OSA) syndrome, which, in turn, is considered a life-threatening condition. It is known that in severe forms of OSA syndrome, up to 400-500 respiratory stops per night with a total duration of up to 3-4 hours can occur, which leads to acute and chronic lack of oxygen during sleep. In turn, chronic obstructive pulmonary disease (COPD) is one of the most common diseases and one of the leading causes of death worldwide. The association of OSA syndrome and COPD, which is designated by the term overlap syndrome, is characterized by the summation of the negative effect of these pathological conditions on the parameters of blood oxygen saturation during night sleep. Diagnosis, treatment and prognosis in patients with overlap syndrome should be based on an interdisciplinary approach, including the use of modern and highly informative methods of functional diagnosis. To date, many methods of treatment (conservative, surgical, combined) of rhonchopathy and OSA syndrome are known. In most cases, preference is given to minimally invasive methods, creating constant positive pressure in the respiratory tract. Tracheostomy is an absolutely effective method of treating OSA syndrome, however, it is very traumatic, but in exceptional cases it is necessary. This paper describes a clinical case of installing a T-shaped stent not only for the treatment of chronic cicatricial stenosis, but also to compensate for OSA syndrome and restore vocal function.

Overlaps between obstructive sleep apnoea and other respiratory diseases, including COPD, asthma and interstitial lung disease

In the past, there was limited research relating to the role of sleep in respiratory diseases. Physicians treating these patients tended to focus mainly on the daily disabling symptoms, overlooking the possible significant role of coexisting sleep disorders such as obstructive sleep apnoea (OSA). Nowadays, OSA has been recognised as an important, highly prevalent comorbidity for respiratory diseases such as COPD, asthma and interstitial lung diseases (ILDs). Overlap syndrome refers to the coexistence of chronic respiratory disease and OSA in the same patient. Although, in the past, overlap syndromes have been poorly studied, recent data underline that they result in increased morbidity and mortality compared with either underlying disorder alone. OSA and respiratory disease may be of different severity, and this, along with the existence of various clinical phenotypes, points to the necessity of an individualised therapeutic plan. Early recognition and OSA management could offer key benefits, such as improved sleep, quality of life and disease outcomes.

Educational aims

Describe pathophysiological aspects of OSA in chronic respiratory diseases such as COPD, asthma and ILDs.Understand the bidirectional clinical importance when OSA coexists in chronic respiratory diseases.Review current knowledge of treatment strategies towards an individualised therapeutic plan resulting in patient-centric outcomes.

Dysregulation of the Nitric Oxide/Dimethylarginine Pathway in Hypoxic Pulmonary Vasoconstriction—Molecular Mechanisms and Clinical Significance

The pulmonary circulation responds to hypoxia with vasoconstriction, a mechanism that helps to adapt to short-lived hypoxic episodes. When sustained, hypoxic pulmonary vasoconstriction (HPV) may become deleterious, causing right ventricular hypertrophy and failure, and contributing to morbidity and mortality in the late stages of several chronic pulmonary diseases. Nitric oxide (NO) is an important endothelial vasodilator. Its release is regulated, amongst other mechanisms, by the presence of endogenous inhibitors like asymmetric dimethylarginine (ADMA). Evidence has accumulated in recent years that elevated ADMA may be implicated in the pathogenesis of HPV and in its clinical sequelae, like pulmonary arterial hypertension (PAH). PAH is one phenotypic trait in experimental models with disrupted ADMA metabolism. In high altitude, elevation of ADMA occurs during long-term exposure to chronic or chronic intermittent hypobaric hypoxia; ADMA is significantly associated with high altitude pulmonary hypertension. High ADMA concentration was also reported in patients with chronic obstructive lung disease, obstructive sleep apnoea syndrome, and overlap syndrome, suggesting a pathophysiological role for ADMA-mediated impairment of endothelium-dependent, NO-mediated pulmonary vasodilation in these clinically relevant conditions. Improved understanding of the molecular (dys-)regulation of pathways controlling ADMA concentration may help to dissect the pathophysiology and find novel therapeutic options for these diseases.

Elevated Monocytic Interleukin-8 Expression under Intermittent Hypoxia Condition and in Obstructive Sleep Apnea Patients

Obstructive sleep apnea (OSA) is a disease with great cardiovascular risk. Interleukin-8 (IL-8), an important chemokine for monocyte chemotactic migration, was studied under intermittent hypoxia condition and in OSA patients. Monocytic THP-1 cells were used to investigate the effect of intermittent hypoxia on the regulation of IL-8 by an intermittent hypoxic culture system. The secreted protein and mRNA levels were studied by means of enzyme-linked immunosorbent assay and RT/real-time PCR. The chemotactic migration of monocytes toward a conditioned medium containing IL-8 was performed by means of the transwell filter migration assay. Peripheral venous blood was collected from 31 adult OSA patients and RNA was extracted from the monocytes for the analysis of IL-8 expression. The result revealed that intermittent hypoxia enhanced the monocytic THP-1 cells to actively express IL-8 at both the secreted protein and mRNA levels, which subsequently increased the migration ability of monocytes toward IL-8. The ERK, PI3K and PKC pathways were demonstrated to contribute to the activation of IL-8 expression by intermittent hypoxia. In addition, increased monocytic IL-8 expression was found in OSA patients, with disease severity dependence and diurnal changes. This study concluded the monocytic IL-8 gene expression can be activated by intermittent hypoxia and increased in OSA patients.