Sleep disorders in chronic obstructive pulmonary disease: etiology, impact, and management

Identification of sleep phenotypes in COPD using machine learning-based cluster analysis

BACKGROUND

Disturbed sleep in patients with COPD impact quality of life and predict adverse outcomes.

RESEARCH QUESTION

To identify distinct phenotypic clusters of patients with COPD using objective sleep parameters and evaluate the associations between clusters and all-cause mortality to inform risk stratification.

STUDY DESIGN AND METHODS

A longitudinal observational cohort study using nationwide Veterans Health Administration data of patients with COPD investigated for sleep disorders. Sleep parameters were extracted from polysomnography physician interpretation using a validated natural language processing algorithm. We performed cluster analysis using an unsupervised machine learning algorithm (K-means) and examined the association between clusters and mortality using Cox regression analysis, adjusted for potential confounders, and visualized with Kaplan-Meier estimates.

RESULTS

Among 9992 patients with COPD and a clinically indicated baseline polysomnogram, we identified five distinct clusters based on age, comorbidity burden and sleep parameters. Overall mortality increased from 9.4 % to 42 % and short-term mortality (<5.3 years) ranged from 3.4 % to 24.3 % in Cluster 1 to 5. In Cluster 1 younger age, in 5 high comorbidity burden and in the other three clusters, total sleep time and sleep efficiency had significant associations with mortality.

INTERPRETATION

We identified five distinct clinical clusters and highlighted the significant association between total sleep time and sleep efficiency on mortality. The identified clusters highlight the importance of objective sleep parameters in determining mortality risk and phenotypic characterization in this population.

Prevalence and Characteristics of Patients with Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease: Overlap Syndrome

Overlap syndrome (OVS) is a distinct clinical entity that seems to result in potential cardiovascular consequences. We aimed to estimate the prevalence and risk factors for OVS in OSA patients and analyze clinical and PSG characteristics associated with OVS. In this cross-sectional study, 2616 patients evaluated for OSA underwent type-1 polysomnography (PSG). They were grouped as pure OSA (AHI > 15/h) and OVS patients. Demographics, PSG data, pulmonary function tests and arterial blood gases (ABGs) were compared between groups after adjustments for confounders. OSA was diagnosed in 2108 out of 2616 patients. Of those, 398 (19%) had OVS. Independent predictors of OVS were older age [OR: 5.386 (4.153-6.987)], current/former smoking [OR: 11.577 (7.232-18.532)], BMI [OR: 2.901 (2.082-4.044)] and ABG measurements [PaCO2 ≥ 45 OR: 4.648 (3.078-7.019), PO2 [OR: 0.934 (0.920-0.949)], HCO3- [OR: 1.196 (1.133-1.263), all p < 0.001]. OVS was also associated with prevalent hypertension [OR: 1.345 (1.030-1.758), p = 0.03] and cardiovascular disease [OR: 1.617 (1.229-2.126), p < 0.001], depressive symptoms [OR: 1.741 (1.230-2.465), p = 0.002] and nocturia [OR: 1.944 (1.378-2.742), p < 0.001], as well as with indices of OSA severity. Disturbances in sleep architecture were more prominent in OVS expressed by lower %N3 and REM% and higher arousal index. Our data suggest that OVS is prevalent among OSA patients, with distinct clinical and PSG characteristics. These characteristics could be utilized as predictive factors for early identification and further evaluation of these patients towards desirable patient-reported outcomes.

Assessment of Obstructive Sleep Apnea Among Patients With Chronic Obstructive Pulmonary Disease in Primary Care

Study Objectives

Observational studies link untreated obstructive sleep apnea (OSA) with adverse outcomes in chronic obstructive pulmonary disease (COPD). The first step in addressing OSA is a clinical assessment. However, given competing demands and a lack of high-quality evidence, it is unclear how often such assessments occur. We explored the documentation of OSA assessment among patients with COPD in primary care, and the patient and provider characteristics associated with these assessments.

Methods

We conducted a cross-sectional study of patients with clinically diagnosed COPD at 2 primary care practices. We abstracted charts to determine whether providers assessed OSA, defined as documentation of symptoms, treatment, or a referral to sleep medicine. We performed multivariable mixed-effects logistic regression to assess the associations of patient and provider characteristics with OSA assessment.

Results

Among 641 patients with clinically diagnosed COPD, 146 (23%) had OSA assessed over a 1-year period. Positive associations with OSA assessment included body mass index ≥ 30 (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.8-7.0), pulmonary subspecialist visits (OR 3.9, 95%CI 2.4-6.3), and a prior sleep study demonstrating OSA documented within the electronic medical record (OR 18.0, 95%CI 9.0-35.8). Notably, patients identifying as Black were less likely to have OSA assessed than those identifying as White (OR 0.5, 95%CI 0.2-0.9).

Conclusions

Providers document an assessment of OSA among a quarter of patients with COPD. Our findings highlight the importance of future work to rigorously test the impact of assessment on important health outcomes. Our findings also reinforce that additional strategies are needed to improve the equitable delivery of care.

Sex-differences in COPD: from biological mechanisms to therapeutic considerations

Chronic obstructive pulmonary disease (COPD) is a heterogeneous respiratory condition characterized by symptoms of dyspnea, cough, and sputum production. We review sex-differences in disease mechanisms, structure-function-symptom relationships, responses to therapies, and clinical outcomes in COPD with a specific focus on dyspnea. Females with COPD experience greater dyspnea and higher morbidity compared to males. Imaging studies using chest computed tomography scans have demonstrated that females with COPD tend to have smaller airways than males as well as a lower burden of emphysema. Sex-differences in lung and airway structure lead to critical respiratory mechanical constraints during exercise at a lower absolute ventilation in females compared to males, which is largely explained by sex differences in maximum ventilatory capacity. Females experience similar benefit with respect to inhaled COPD therapies, pulmonary rehabilitation, and smoking cessation compared to males. Ongoing re-assessment of potential sex-differences in COPD may offer insights into the evolution of patterns of care and clinical outcomes in COPD patients over time.

Postural balance in COPD with obstructive sleep apnoea: a cross-sectional study

Objective

The aim of this study was to assess the postural balance in COPD patients with obstructive sleep apnoea (OSA). Physical activity, anxiety and depression symptoms, mood, and falls were also assessed in this population.

Methods

Moderate to severe COPD patients were assessed for laboratory and clinical postural balance (force platform and mini-balance evaluation systems test (Mini-BESTest)), physical activity (accelerometry), OSA (polysomnography), sleep quality (Pittsburgh Sleep Quality Index), sleepiness (Epworth Sleepiness Scale), anxiety and depression symptoms (Hospital Anxiety and Depression Scale), dyspnoea (modified Medical Research Council), clinical status (COPD Assessment Test) and mood (Brunel Mood Scale). Self-reported falls were recorded for 6 months via phone calls.

Results

COPD patients (n=70) were divided according to the polysomnography findings into the no OSA (n=30), mild OSA (n=25), and moderate to severe OSA (n=15) groups. Compared to patients with no OSA, those with moderate to severe OSA (msOSA group) presented median (interquartile range) increased path length (30.5 (23.9-34.5) cm versus 39.0 (30.6-52.6) cm, anteroposterior displacement (1.89 (1.39-2.31) cm versus 2.54 (2.06-2.83) cm and postural adjustment velocity (1.02 (0.80-1.15) cm·s-1 versus 1.30 (1.02-1.76) cm·s-1) (p<0.05). No differences were observed in the Mini-BESTest scores among the groups. The msOSA group presented a greater number of recurrent fallers in the first follow-up trimester. No association was observed between postural balance and age and pulmonary function.

Conclusion

Individuals with COPD and moderate to severe OSA present changes in postural balance, including broader oscillation, faster postural adjustments and a greater risk of falls than those with no OSA. Physical activity, anxiety and depression symptoms, and mood are similar between COPD patients with and without OSA.

The Six Pillars of Lifestyle Medicine in Managing Noncommunicable Diseases - The Gaps in Current Guidelines

BACKGROUND

Noncommunicable diseases (NCDs), also known as chronic diseases that are long-lasting, are considered the major cause of death and disability worldwide, and the six pillars of lifestyle medicine (nutrition, exercise, toxic control, stress management, restorative sleep, and social connection) play an important role in a holistic management of their prevention and treatment. In addition, medical guidelines are the most accepted documents with recommendations to manage NCDs.

OBJECTIVE

The present study aims to analyze the lack of lifestyle pillars concerning the major Brazilian medical guidelines for NCDs and identify evidence in the literature that could justify their inclusion in the documents.

METHOD

Brazilian guidelines were selected according to the most relevant causes of death in Brazil, given by the Mortality Information System, published by the Brazilian Ministry of Health in 2019. Journals were screened in the PUBMED library according to the disease and non-mentioned pillars of lifestyle.

RESULTS

Relevant causes of deaths in Brazil are acute myocardial infarction (AMI), diabetes mellitus (DM), and chronic obstructive pulmonary diseases (COPD). Six guidelines related to these NCDs were identified, and all address aspects of lifestyle, but only one, regarding cardiovascular prevention, highlights all six pillars. Despite this, a literature search involving over 50 articles showed that there is evidence that all the pillars can help control each of these NCDs.

CONCLUSION

Rarely are the six pillars of lifestyle contemplated in Brazilian guidelines for AMI, DM, and COPD. The literature review identified evidence of all lifestyle pillars to offer a holistic approach for the management and prevention of NCDs.

The Overlap Syndrome: A Combination of Chronic Obstructive Pulmonary Disease and Obstructive Sleep Apnea

Chronic obstructive pulmonary disease (COPD) is a severe lung disease that results in persistent and progressively worsening airflow obstruction due to abnormalities in the airway and alveoli. Obstructive sleep apnea (OSA) is a critical condition characterized by obstructive apneas, hypopneas, and respiratory effort-related arousals. These events occur due to the repetitive collapse of the upper airway during sleep, and it is essential to address this condition. These two conditions, when co-occur, are known as overlap syndrome (OS), which is associated with a higher likelihood of morbidity and mortality compared to either condition alone. Effective management of overlap syndrome is critical to maintain normal oxygen levels during sleep and reduce the incidence of hypoxemia and hypoventilation while improving sleep quality. Positive pressure ventilation is a standard technique used to effectively lower hospitalizations, emergency room visits, moderate and severe exacerbations, and related healthcare expenses in patients diagnosed with COPD and OSA. Despite the lack of literature on overlap syndrome, it is imperative to understand that this condition requires prompt and effective management to prevent further complications. Therefore, this review provides a detailed discussion highlighting the importance of proactive measures to manage overlap syndrome.

Risks of Zolpidem among Patients with Chronic Obstructive Pulmonary Disease

Rationale: Nonbenzodiazepine benzodiazepine receptor agonists (NBZRA, e.g., zolpidem) are frequently used to treat insomnia among patients with chronic obstructive pulmonary disease (COPD). However, multiple observational studies find that patients with COPD who are prescribed NBZRAs have greater risks for mortality and respiratory complications than patients without such prescriptions. Without an active comparator, these studies are susceptible to confounding by indication. Objectives: Compare the risk of death or inpatient COPD exacerbation among patients receiving zolpidem relative to patients receiving other hypnotics. Methods: Using nationwide Veterans Health Administration (VA) data, we identified patients with clinically diagnosed COPD and new receipt of zolpidem or another hypnotic available on VA formulary without prior authorization (melatonin, trazodone, doxepin). We excluded those receiving traditional benzodiazepines or multiple concurrent hypnotics. We propensity-matched patients receiving zolpidem to other hypnotics on 32 variables, including demographics, comorbidities, and markers of COPD severity. We compared risk of the primary composite outcome of death or inpatient COPD exacerbation over 1 year. In secondary analyses, we propensity-matched patients receiving zolpidem to those without hypnotic receipt. Results: Among 283,740 patients meeting inclusion criteria, 1,126 (0.4%) received zolpidem and 3,057 (1.1%) received other hypnotics. We propensity-matched patients receiving zolpidem 1:1 to peers receiving other hypnotics. We did not find a difference in the primary composite outcome of death or inpatient exacerbation (hazard ratio, 0.97; 95% confidence interval [CI], 0.77-1.23). In secondary analyses comparing patients receiving zolpidem to matched peers without hypnotic receipt, we observed greater risk of death or inpatient exacerbation with zolpidem (hazard ratio, 1.40; 95% CI, 1.09-1.81). Conclusions: Among patients with COPD, we did not observe greater risks after new receipt of zolpidem relative to other hypnotics. However, we did observe greater risks relative to those without hypnotic receipt. This latter finding may reflect: 1) residual, unmeasured confounding related to insomnia; or 2) true adverse effects of hypnotics across classes. Future work is needed to better understand the risks of hypnotics in COPD.

Co-existence of OSA and respiratory diseases and the influence of gender

INTRODUCTION

Sleep-disordered breathing (SDB), especially obstructive sleep apnea (OSA), is commonly associated with respiratory diseases, such as COPD, asthma and interstitial lung disease.

AREAS COVERED

This narrative review aims to comprehensively synthesize the existing information on SDB in respiratory diseases, investigate the role of gender in this association, and highlight the importance of OSA management in improving sleep, quality of life, and disease prognosis in these specific patient populations.

EXPERT OPINION

Research indicates a synergistic link between OSA and chronic respiratory diseases, which leads to greater morbidity and mortality compared to each disorder alone. Given the lack of an optimal OSA screening tool for these patients, a comprehensive patient approach and overnight diagnostic sleep study are imperative. Despite the limited evidence available, it seems that gender has an impact on the prevalence, severity, and susceptibility of this coexistence. Recognizing the role of gender in the coexistence of OSA and other respiratory diseases can enhance everyday medical practice and enable clinicians to adopt a more personalized approach toward optimal screening and diagnosis of these patients.

Sleep Hypoventilation is Common in Diurnal Normocapnic COPD Patients with Severe or Very Severe Obstruction and is Not Associated with Body Mass Index

Sleep hypoventilation (SH) is common in COPD patients with diurnal hypercapnia, however there are little data on the presence of SH in COPD patients with diurnal normocapnia. In this study the prevalence of SH in stable normocapnic COPD patients with severe or very severe obstruction (GOLD stages III and IV) was evaluated across body mass index (BMI) classes and associations between SH and body composition measures were explored. A total of 56 diurnal normocapnic COPD patients, of whom 17 normal-weight (COPD_NW), 18 overweight (COPD_OW) and 21 obese (COPD_OB), underwent polysomnography to objectify SH and bioelectrical impedance analysis to assess body composition. The overall prevalence of SH was 66.1% and was not different across BMI classes. Logistic regression models indicated that SH was not associated with waist-to-hip ratio, body fat percentage and fat-free mass index. Our data indicate that SH is common in diurnal normocapnic COPD patients with severe or very severe obstruction and is not associated with BMI or body composition.

Mortality in obstructive sleep apnea syndrome (OSAS) and overlap syndrome (OS): The role of nocturnal hypoxemia and CPAP compliance

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD) are two chronic diseases that afflict many individuals worldwide with negative effects on health that may overlap in Overlap Syndrome (OS). The aim of our study was to investigate the differences in mortality between OSAS alone and OS and the risk factors involved.

METHODS

The study was conducted on patients with OSAS or OS diagnosis that completed 15-year follow-up between 2005 and 2023. Of these, the clinical, functional, sleep and survival data were registered and analysed. Risk factors were found by regression analysis.

RESULTS

501 patients (428 OSAS and 73 OS) were enrolled. Patients with OS had higher mortality than OSAS (p < 0,001). The morality risk factors for the overall population found were age >65 years (odds ratio (OR) = 10.69 (95%CI 3,85-29,69), p < 0,001) and low forced-expiratory volume in 1-s (FEV1) (OR = 10.18 (95%CI 2,32-44,68), p = 0,002). In patients with OSAS, age and nocturnal hypoxemia (NH) (OR = 2.41 (95%CI 1,07-5,41), p = 0,03) were risk factors, while adherence to nighttime positive airway pressure (PAP) reduced mortality (OR = 0,36 (95%CI 0,15-0,83), p = 0,017). Multivariate analysis confirmed age and FEV1 as risk factors in OS. Conversely, the risk factors for the overall population under 65 years were NH, which is confirmed in patients with OSAS alone (OR = 4,72 (95%CI 1,07-20,77), p = 0,04) in whom, on the other hand, PAP compliance reduced the mortality risk.

CONCLUSIONS

The study suggests that NH is a risk factor for all-cause mortality in sleep disorders by excluding the age; conversely, nighttime PAP improves the survival.

Reliability generalization meta-analysis of the Athens Insomnia Scale and its translations: Examining internal consistency and test-retest validity

The Athens Insomnia Scale (AIS) is a widely used self-report measure to evaluate insomnia symptoms based on the International Classification of Diseases criteria version 10 (ICD-10). Despite its extensive use in clinical and research settings, the reliability of the AIS has not been systematically investigated. This systematic review reports a reliability generalization meta-analysis study to assess the internal consistency and the test-retest reliability of the AIS across various populations and settings. A systematic literature search was conducted to identify studies reporting Cronbach's alpha and test-retest coefficients for the AIS. Pooled estimates of reliability, along with moderator analyses, were calculated. The AIS has an excellent internal consistency of 0.84 (95% CI: 0.81 to 0.86), and re-test reliability of 0.86 (95% CI: 0.80 to 0.92). The significant heterogeneity levels support the recommendation that future studies using the AIS include and discuss reliability estimates based on their own data.

The Impact of Lung Function Parameters on Sleep Among Aboriginal Australians - A Polysomnography and Spirometry Relationship Study

Background

Sleep disorders such as obstructive sleep apnoea (OSA) are known to overlap significantly with airway diseases in various populations. This study assessed the relationship between lung function parameters against polysomnography (PSG) and continuous positive airway pressure (CPAP) adherence data amongst an Aboriginal Australian population.

Methods

Patients who undertook both a diagnostic PSG and spirometry were included. Restrictive, obstructive, and mixed impairments were assessed via global lung function initiative (GLI-2012, ATS/ERS) criteria/guidelines. PSG and CPAP data were evaluated between patients with or without spirometry impairments.

Results

Of the total 771 patients, 248 had PSG and spirometry data available (52% female, 44% remote residents, 78% obese). The majority (89%) had OSA (51% severe), 95 (38%) were observed to have a restrictive impairment, and 31 (13%) had an obstructive or mixed impairment on spirometry. Compared to patients with no spirometric impairment, those with restrictive or obstructive/mixed impairments demonstrated significantly lower sleep efficiency (median 84% vs 79% and 78%), higher apnoea-hypopnea index (AHI) during rapid eye movement (REM) sleep (median 32 vs 52 and 55 events/hour), reduced REM oxygen saturation (SpO₂) (median 94.0% vs 92.0% and 92.5%) and reduced adherence to CPAP therapy (median 39% vs 22% and 17%). Differences in sleep efficiency, REM AHI, and NREM SpO₂ held for patients with obstructive/mixed impairments in multivariate modelling.

Conclusion

Aboriginal Australian patients with OSA have a higher concurrent lung function' impairment. Spirometric impairment appears to negatively influence sleep efficiency, nocturnal SpO₂ and CPAP adherence. This may have substantial implications for OSA management among Aboriginal Australians.

Insomnia in chronic obstructive pulmonary disease and associations with healthcare utilization and costs

Insomnia has been linked to adverse chronic obstructive pulmonary disease (COPD) outcomes including exacerbations, yet its impact on COPD-related healthcare utilization and costs is unknown. In this study, we investigated the associations between insomnia and healthcare utilization and costs in patients with COPD. A retrospective cohort of veterans with COPD were identified from national Veterans Affairs administration data for fiscal years 2012-2017. Insomnia was operationalized as having an insomnia diagnosis based on International Classification of Disease codes or having a prescription of > 30 doses of a sedative-hypnotic medication in a given fiscal year. The index date for insomnia was the first date when dual criteria for COPD and insomnia was met. The index date for those without insomnia was set as the COPD index date. Our primary outcomes were 1-year healthcare utilization and costs related to outpatient visits and hospitalizations after index date. COPD-related healthcare utilization variables included number of prescription fills of corticosteroids and/or antibiotics and outpatient visits and hospitalizations with a primary diagnosis of COPD. Out of 1,011,646 patients (96% men, mean age 68.4 years) diagnosed with COPD, 407,363 (38.8%) had insomnia. After adjustment for confounders, insomnia was associated with higher rates of outpatient visits, hospitalizations, and fills for corticosteroids and/or antibiotics, longer hospital length of stay, and $10,344 higher hospitalization costs in the 12 months after index date. These findings highlight the importance of insomnia as a potentially modifiable target for reducing the burden of COPD on patients and healthcare systems.

Sleep Quality and Self-Reported Symptoms of Anxiety and Depression Are Associated with Physical Activity in Patients with Severe COPD

Sleep quantity, quality and symptoms of depression or anxiety potentially affect the level of daily physical activity (PAL) and plausibly counteracts benefits from pulmonary rehabilitation programs. Their collective impact on PAL is sparsely investigated, particularly in patients with severely progressed chronic obstructive pulmonary disease (COPD). Aim: To investigate if sleep quantity, quality and symptoms from self-reported hospital anxiety and depression scores (HADS) are associated with PAL. Methods: In this exploratory cross-sectional study data were analysed from 148 participants with COPD; GOLD grade II-IV; GOLD group B to D (52% female, mean 69.7 ± SD of 8.4 years, FEV1% predicted 33.6 ± 10.9, 6MWD 327 ± 122 m, CAT 20 ± 7 points), eligible for conventional outpatient hospital-based pulmonary rehabilitation. Participants had sleep and PAL measured 24 h per day for five consecutive days with an activPAL monitor. Adjusted negative binomial regression was applied to investigate the associations with PAL. Results: Participants walked median (25th, 75th percentile) of 2358 (1325.75; 3822.25) steps per day and 14% walked >5000 steps per day on average. Time in bed (TIB) were a median (25th, 75th percentile) of 8.3 (7.1; 9.7) hours and numbers of nocturnal sleeping bouts (NSB) were 1.5 (0.8; 3), Anxiety (HADS-A) and depression (HADS-D) scores were median (25th, 75th percentile) of 5 (3; 8) points and 3 (2; 6) points, respectively, whereof 29% (HADS-A) and 15% (HADS-D) reported scores ≥8 points indicating significant symptoms. The fully adjusted rate ratio (RR) for steps per day for TIB (hours) [RR 0.97 (95% CI: 0.92; 1.02)], NSB (numbers) [RR 1.02 (95% CI: 0.97; 1.07)] were not significantly associated with number of steps per day, while there was a significantly association with number of steps per day for HADS-A [RR 1.04 (95% CI: 1.01; 1.07)] and HADS-D [RR 0.95 (95% CI: 0.91; 0.99)]. Conclusion: This exploratory cross-sectional study found a statistically significant association between HADS-A and HADS-D with numbers of steps per day in patients with severe COPD.

Impact of Positive Airway Pressure Therapy Adherence on Outcomes in Patients with Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease

Rationale: The co-occurrence of obstructive sleep apnea and chronic obstructive pulmonary disease, termed overlap syndrome, has a poor prognosis. However, data on positive airway pressure (PAP) treatments and their impact on outcomes and costs are lacking. Objectives: This retrospective observational study investigated the effects of PAP on health outcomes, resource usage, and costs in patients with overlap syndrome. Methods: Deidentified adjudicated claims data for patients with overlap syndrome in the United States were linked to objectively measured PAP user data. Patients were considered adherent to PAP therapy if they met Centers for Medicare and Medicaid Services criteria for eight 90-day timeframes from device setup through 2-year follow-up. Propensity score matching was used to create comparable groups of adherent and nonadherent patients. Healthcare resource usage was based on the number of doctor visits, all-cause emergency room visits, all-cause hospitalizations, and PAP equipment and supplies, and proxy costs were obtained. Measurements and Main Results: A total of 6,810 patients were included (mean age, 60.8 yr; 56% female); 2,328 were nonadherent. Compared with the year before therapy, there were significant reductions in the number of emergency room visits, hospitalizations, and severe acute exacerbations during 2 years of PAP therapy in patients who were versus were not adherent (all P < 0.001). This improvement in health status was paralleled by a significant reduction in the associated healthcare costs. Conclusions: PAP usage by patients with overlap syndrome was associated with reduced all-cause hospitalizations and emergency room visits, severe acute exacerbations, and healthcare costs.

Prevalence, risk factors and effects of restless legs syndrome in COPD patients

Restless legs syndrome (RLS), a sensory motor disorder, is commonly seen amongst chronic obstructive pulmonary disease (COPD) patients. We conducted a study to know its prevalence in COPD and analyse the possible cause and effect of RLS. It is an analytical cross-sectional study conducted between July 2016-December 2020.The prevalence of RLS was evaluated in patients of COPD using RLS diagnostic criteria. Spirometry, iron profile and arterial blood gas analysis was performed in all the patients to evaluate the cause of RLS. The effect was evaluated with diagnostic criteria for insomnia and patient health questionnaire (PHQ2) for depression. There were 205 participants with a mean age of 59±8 years, 182 (88.7%) men and 23 (11.2%) women. The mean body mass index (BMI) was 29±3.9 kg/m2. The prevalence of RLS was 31.2%. RLS was more common amongst women compared to men (60.8% vs 27.4%). RLS was more prevalent among hypoxemic (PaO2<60 mm Hg) and hypercapnic (PaCO2>45 mm Hg) patients (p<0.016; p<0.017). The ROC curve plotted between PaO2 and RLS occurrence showed that the patients having PaO2 less than 76 mm of Hg were more prone to develop RLS. RLS patients had a higher incidence of insomnia as compared to those without RLS (68.8% vs 36.8%, p<0.001). COPD with RLS patients had more depressive symptoms with a higher patient health questionnaire 2 (PHQ2) score (35.9% vs 14.2%, p<0.001) compared to non-RLS COPD patients. The multiple regression analysis also confirmed that RLS led to insomnia and depressive symptoms in COPD patients. To conclude, RLS is common in COPD patients. RLS leads to insomnia and depression, thus should be identified and treated.

Association of self-reported sleep problems with morbidities and multimorbidities according to sex: National Health Survey 2019

OBJECTIVE

To evaluate the association between self-reported sleep problems and the presence of non-communicable diseases (NCDs) and multimorbidity, and whether these associations differ by sex.

METHODS

This is a cross sectional study performed with data from the Brazilian National Health Survey, 2019. Prevalence ratios between morbidities, the number of NCDs, and the self-report of sleep problems were estimated by Poisson regression with robust variance, according to sex.

RESULTS

This study analysed data from 85,531 Brazilians age ≥ 18 years. The self-reported sleep problems were associated with all the herein studied morbidities and multimorbidities. The prevalence of sleep problems was higher in those who stated one or two (PR = 2.37; 95%CI 2.22;2.54) and three or more NCDs (PR = 4.73; 95%CI 4.37;5.11). Prevalence ratios of the association with diabetes, lung disease, mental disease, renal disease and multimorbidities were higher among males.

CONCLUSION

NCDs significantly impacted sleep quality, with a particularly stronger association in both, males and females.

Adding Insult to Injury: Sleep Deficiency in Hospitalized Patients

Sleep deficiency is a common problem in the hospital setting. Contributing factors include preexisting medical conditions, illness severity, the hospital environment, and treatment-related effects. Hospitalized patients are particularly vulnerable to the negative health effects of sleep deficiency that impact multiple organ systems. Objective sleep measurement is difficult to achieve in the hospital setting, posing a barrier to linking improvements in hospital outcomes with sleep promotion protocols. Key next steps in hospital sleep promotion include improvement in sleep measurement techniques and harmonization of study protocols and outcomes to strengthen existing evidence and facilitate data interpretation across studies.

Is obstructive sleep apnea associated with increased arterial stiffness in patients with COPD?

PURPOSE

To evaluate arterial stiffness, a predictor of vascular damage was assessed by means of pulse wave velocity (PWV) in patients with chronic obstructive pulmonary disease (COPD) and comorbid obstructive sleep apnea (OSA), namely overlap syndrome (OS).

METHODS

Consecutive stable patients with COPD were evaluated for OSA by means of overnight polysomnography in the laboratory. A clinical assessment was performed according to a strict protocol, including two COPD questionnaires: the COPD assessment test and the modified Medical Research Council scale. COPD severity was graded according to the guidelines of the Global Initiative for Chronic Obstructive Lung Disease. Arterial stiffness was assessed by means of PWV, using a standard technique.

RESULTS

Of 102 patients with COPD, 51 had associated OSA. The OS group had more men than the COPD group (73% vs. 47%, respectively; p < 0.01). Both groups had similar ages (66.2 ± 9.2 years vs. 69.6 ± 10.7, p = 0.09) and airflow limitation (p = 0.37). Hypertension was found in 22% of COPD patients, as opposed to 17% patients in the OS group (p = 0.29). High PWV values were present in 42% of the patients. Patients with COPD and OS had the same PWV values (9.8 vs. 10.5 m/s, p = 0.34). There were no differences in central blood pressure, peripheral blood pressure, and augmentation index between the two groups (p > 0.05).

CONCLUSION

High PWV values were frequently observed in patients with COPD. However, there was no difference in PWV between patients with OS and those with COPD alone.

Sleep quality in COPD patients: correlation with disease severity and health status

Objective:

To evaluate clinical predictors of poor sleep quality in COPD patients with and without obstructive sleep apnea (OSA).

Methods:

Consecutive stable patients with COPD were evaluated for OSA by means of overnight polysomnography; for sleep quality by means of the Pittsburgh Sleep Quality Index (PSQI); and for disease impact by means of the COPD Assessment Test. COPD severity was graded in accordance with the 2020 GOLD guidelines. Predictors of poor sleep quality were evaluated by multivariate logistic regression analysis.

Results:

We studied 51 patients with COPD alone and 51 patients with COPD and OSA. Both groups had similar age (66.2 ± 9.2 years vs. 69.6 ± 10.7, p = 0.09) and airflow limitation (p = 0.37). Poor sleep quality was present in 74.8% of the study participants, with no significant difference between COPD patients with and without OSA regarding PSQI scores (p = 0.73). Polysomnography showed increased stage 1 non-rapid eye movement sleep and arousal index, as well as reduced sleep efficiency and stage 3 non-rapid eye movement sleep, in the group of patients with COPD and OSA (p < 0.05). Independent predictors of poor sleep quality were GOLD grade C/D COPD (OR = 6.4; 95% CI, 1.79-23.3; p < 0.01), a COPD Assessment Test score ≥ 10 (OR = 12.3; 95% CI, 4.1-36.5; p < 0.01), and lowest SaO₂ < 80% (p < 0.0001).

Conclusions:

Poor sleep quality is quite common in patients with COPD and is associated with severe COPD and poor health status, having a negative impact on overall quality of life. Despite changes in polysomnography, OSA appears to have no impact on subjective sleep quality in COPD patients.

Synergistic Impact of the Symptom Cluster on Health-Related Quality of Life in Patients With Chronic Obstructive Pulmonary Disease: A Secondary Data Analysis

This study aimed to quantify the synergistic impact of symptom clusters on health-related quality of life (HRQoL) among patients with chronic obstructive pulmonary disease (COPD). We conducted a secondary analysis of a cross-sectional data collected via convenience sampling from patients with COPD. Multiple linear regressions were used to quantify the relationships between symptom clusters and HRQoL. The sample included 106 COPD patients from whom three symptom clusters were identified comprising of dyspnea depression, anxiety-sleep, and depression-anxiety. Depression-anxiety (psychological symptom cluster) was significantly associated with poorer HRQoL (β = 13.88, 95% CI [7.94, 19.82]), while no significant associations were detected with HRQoL for either depression or anxiety alone (β = 6.66, 95% CI [-2.99, 16.31]; β = 7.29, 95% CI [-0.78, 15.35]). Assessment and early intervention led by nurses targeting the psychological symptom cluster may represent an initial approach to improve HRQoL. Understanding the phenomenon of symptom clusters that are present in patients with COPD provides a breakthrough insight to devise strategies for their management.

Sleep-Related Breathing Complaints in Chronic Obstructive Pulmonary Disease

This review presents the normal physiologic changes in ventilation during sleep and how they can be detrimental to chronic obstructive pulmonary disease (COPD). Sleep-related breathing disorders (SRBDs) in COPD lead to higher morbidity and mortality if left unrecognized and untreated. The diagnosis of SRBDs requires a high index of suspicion, as symptoms may overlap with other sleep disorders. Mortality risk is improved when patients with COPD with OSA (overlap syndrome) are treated with positive airway pressure and when long-term nocturnal noninvasive ventilation is started on chronic stable hypercapnic COPD. Treatment of isolated nocturnal oxygen desaturation has not been associated with improved survival.

Sleep, substance misuse and addictions: a nationwide observational survey on smoking, alcohol, cannabis and sleep in 12,637 adults

For a good night's sleep, we consensually recommend avoiding alcohol, smoking and drugs. However, these addictions are highly prevalent in the general population, and it is difficult to estimate their real impact on sleep. The aim of this study is to clarify the association between sleep habits and disorders, and addictions. The design was a telephone crossover national recurrent health poll survey (Santé publique France, Baromètre santé, 2017; Questionnaire, pp. 53; Saint Maurice) in a representative sample of French adults. There were 12,367 subjects (18-75 years old) who answered the survey. Sleep log items assessed sleep schedules (total sleep time) on work and leisure days: at night, while napping, and over 24 hr using a sleep log. Retained items include: (1) short sleep (≤ 6 hr/24 hr); (2) chronic insomnia (International Classification of Sleep Disorders, 3^rd edition criteria); and (3) chronotype (evening-morning-neutral). Psychoactive substances retained included tobacco (current or former users), alcohol (daily consumption and weekly binge drinking), cannabis (Cannabis Abuse Screening Test), and other drugs (consumption during the past year). We found that: (1) daily smokers (lightly or heavily dependent) were more frequently short sleepers than occasional smokers and non-smokers; (2) heavily dependent daily smokers were more likely to suffer from insomnia than other smokers or non-smokers; (3) short sleep and insomnia were not significantly associated with the consumption of alcohol, cannabis or any other drug; (4) the evening chronotype was significantly associated with the consumption of tobacco, alcohol and cannabis. In conclusion, our study highlights significant relationships between the use of psychoactive substances and sleep characteristics among adults, emphasizing the need to take into account each subject individually.

Impact of sleep-related hypoventilation in patients with pleuroparenchymal fibroelastosis

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) is a rare fibrosing lung disease with a predilection for the upper lobe and its progression causes hypoventilation, resulting in hypercapnia. Even though the association between sleep-related hypoventilation (SRH) and chronic obstructive pulmonary disease was well documented, its impact in patients with PPFE was not evaluated. The aim of this study is to clarify the impact of SRH on prognosis in PPFE.

METHODS

A retrospective review of the medical records of 52 patients with PPFE who underwent transcutaneous carbon dioxide monitoring during sleep was done. Patients were stratified into SRH (n = 28) and non-SRH (n = 24) groups based on American Academy of Sleep Medicine criteria. The impact of SRH on the prognosis of PPFE, as well as the clinical factors and comorbidities of PPFE associated with SRH, were evaluated.

RESULTS

Forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), total lung capacity (TLC), and carbon monoxide diffusing capacity (DLco) in the SRH group were significantly lower than the non-SRH group (P < .01). Chronic pulmonary aspergillosis (CPA) was found at a higher rate in the SRH group (P = .02). The median survival time for SRH patients was 330 days, whereas roughly 80% of non-SRH patients were alive during the 3-year observation period (P < .01). Body mass index was a significant prognostic factor in PPFE patients with SRH (HR .78; 95% CI; .64-.94; P < .01). Home oxygen therapy (HOT) during the day and noninvasive positive pressure ventilation (NPPV) at night while sleeping tended to improve prognosis in the SRH group, as indicated by HR of .25 (P = .07).

CONCLUSIONS

SRH may be a poor prognostic factor for PPFE. Additionally, SRH may modify susceptibility to Aspergillosis in patients with PPFE. HOT plus NPPV may improve the disease outcomes in patients with SRH.

Sleep Duration and Bedtime in the PURE Poland Cohort Study and the Link with Noncommunicable Diseases

(1) Background: The objective was to investigate the association between sleep duration, bedtime, and noncommunicable diseases in the PURE Poland cohort study. (2) Methods: The baseline study was conducted in 2007-2010. The study group comprised 2023 adult inhabitants of urban and rural areas in Lower Silesia, Poland. The study protocol included questionnaires, blood pressure measurements, blood draws, and anthropometric measurements. Sleep duration and bedtime were self-reported. (3) Results: The median sleep duration of women was 30 min longer than men (8 h vs. 7.5 h; p = 0.001). The average time of sleep increased along with the age of the participants. A sleep duration of >8 h was more common in rural than in urban participants (40.2% vs. 27.1%; respectively; p < 0.001). The relative risk of diabetes, stroke, hypertension, cardiovascular diseases (CVD), and obesity was significantly higher in participants who went to bed between 6 p.m. and 10 p.m. in comparison to those who went to bed between 10 p.m. and 12 a.m. (RR 2.23, 95% CI 1.06-4.67; RR 2.52, 95% CI 1.28 to 4.97; RR 1.12, 95% CI 1.04-1.20; RR 1.36; 95% CI 1.1-1.68; RR 1.38; 95% CI 1.15-1.66, respectively). The relative risk of respiratory diseases was two-fold higher in those who went to bed after midnight in comparison to those who went to bed between 10 p.m. and 12 a.m. (RR 2.24; 95% CI 1.19-4.22). (4) Conclusions: In our study, an earlier bedtime was associated with a higher risk of diabetes, stroke, obesity, hypertension, and CVD.

COPD sleep phenotypes: Genesis of respiratory failure in COPD

The chronic obstructive pulmonary disease (COPD) patients could have respiratory failure during sleep without daytime overt arterial blood gas (ABG) abnormality. We undertook a study first of its kind to attempt in distinguishing the underlying pathophysiological mechanisms.  It was a prospective observational study in stable COPD patients. The inclusion criterion was presence of day time PaO2>60 mmHg and PaCO2<45 mmHg. Twenty five out of 110 patients were excluded because of the ABG abnormality. The remaining 85 patients were subjected to overnight pulse oximetry and end-tidal (ET)-CO2 monitoring. The nocturnal oxygen desaturation was defined as per Fletcher's criteria. The nocturnal hypoventilation was defined as per American academy of sleep medicine (AASM) guidelines. Patients having saw-tooth pattern on pulse oximetry and/or snoring were subjected to polysomnography. 38/85(44.8%) patients had nocturnal gas exchange abnormality in absence of daytime respiratory failure and were identified into 3 different phenotypes: obstructive sleep apnoea (OSA), nocturnal hypoventilation and nocturnal oxygen desaturation. The isolated abnormality was seen in 24 patients: 10 patients had OSA, 9 had nocturnal hypoventilation and 5 had nocturnal oxygen desaturation. Overlap of two or more phenotypes was seen in 14 patients. As compared to the nocturnal hypoventilation and desaturation phenotypes, the OSA phenotype had a significantly higher BMI & FEV1. The nocturnal hypoventilation and the desaturation phenotypes did not have significant difference in FEV1 and BMI, but the daytime SpO2 and PaO2 differed significantly.  Such parameters could help in identifying the three distinct COPD-sleep phenotypes (OSA, nocturnal hypoventilation and nocturnal oxygen desaturation). A phenotype based nocturnal management may help in delaying the process of overt respiratory failure in COPD.

Restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder characterized by an urge to move that appears during rest or is exacerbated by rest, that occurs in the evening or night and that disappears during movement or is improved by movement. Symptoms vary considerably in age at onset, frequency and severity, with severe forms affecting sleep, quality of life and mood. Patients with RLS often display periodic leg movements during sleep or resting wakefulness. RLS is considered to be a complex condition in which predisposing genetic factors, environmental factors and comorbidities contribute to the expression of the disorder. RLS occurs alone or with comorbidities, for example, iron deficiency and kidney disease, but also with cardiovascular diseases, diabetes mellitus and neurological, rheumatological and respiratory disorders. The pathophysiology is still unclear, with the involvement of brain iron deficiency, dysfunction in the dopaminergic and nociceptive systems and altered adenosine and glutamatergic pathways as hypotheses being investigated. RLS is poorly recognized by physicians and it is accordingly often incorrectly diagnosed and managed. Treatment guidelines recommend initiation of therapy with low doses of dopamine agonists or α₂δ ligands in severe forms. Although dopaminergic treatment is initially highly effective, its long-term use can result in a serious worsening of symptoms known as augmentation. Other treatments include opioids and iron preparations.

Characteristics of the nocturnal desaturation waveform pattern of SpO2 in COPD patients: an observational study

BACKGROUND

Nocturnal desaturation is common in patients with chronic obstructive pulmonary disease (COPD) and impacts disease exacerbation and prognosis. In our previous study, we developed a diagnostic algorithm to classify nocturnal desaturation from SpO₂ waveform patterns based on data from patients receiving home oxygen therapy. In this study, we aimed to investigate nocturnal desaturation in patients with COPD based on SpO₂ waveform patterns and the associations between the waveforms and clinical data.

METHODS

We investigated patients diagnosed with COPD and measured SpO₂ and nasal airflow with a type 4 portable long-term recordable pulse oximeter. Then, we classified the SpO₂ waveforms with the algorithm and compared the clinical data.

RESULTS

One hundred fifty-three patients (136 male and 17 female) were analysed. One hundred twenty-eight of the 153 (83.7%) patients had nocturnal desaturation, with an intermittent pattern (70.6%), sustained pattern (13.1%) and periodic pattern (68.0%). Intriguingly, desaturation with an intermittent pattern was associated with the apnoea-hypopnea index obtained with the portable monitor, and desaturation with a sustained pattern was associated with the cumulative percentage of time at a SpO₂ below 90%.

CONCLUSIONS

We found that nocturnal desaturation was frequently observed in patients with COPD and could be classified into 3 types of waveform patterns.

Was Sleep a Problem for the Elderly During COVID-19?

Over the past few decades, the population of geriatrics has seen an exponential rise and it is well known that the prevalence of chronic diseases and other associated comorbidities is higher among them which in turn, has an established association with sleep disorders. During these unprecedented circumstances, geriatrics are predisposed to be at an increased risk of sleep disorders due to the social isolation and loneliness imposed on them by the lockdowns. The fact that older adults are at a greater risk of contracting the virus due to the presence of comorbidities and the high virulence adds on to the existing risk of sleep disturbances. A lack of sleep in these circumstances has the potential to add on to the vicious cycle of sleep disorders predisposed by chronic disease and vice versa. Mental health, sleep and the presence of comorbidities are closely interlinked and they often tend to overlap. Research in sleep has established insomnia to be the most commonly diagnosed sleep disorder affecting almost 50% of the older adults which can subsequently, elevate their risk of falls. This prevalence of sleep disorders is hypothesized to increase during the second wave of the COVID-19 pandemic and a good sleep routine needs to be advocated for to improve the quality of life of this population. However, scientific evidence concerning this is scarce and this review aims to highlight the significance of sleep and urges its readers to undertake studies that investigate the architecture of sleep amongst older adults during the pandemic.

Association Between Sleep Quality and Pain Intensity in Mild Patients with COPD: A Community Study

Purpose

Poor sleep quality and pain were common and had been proved as an important influenced factor of quality of life for patients with COPD. The association of sleep quality with pain has been observed in other population but remains unclear in mild patients with COPD from a community setting.

Methods

A cross-sectional study was conducted to include eligible mild patients with COPD in Pudong New District of Shanghai. A structured questionnaire was used to collect general and clinical information for the patients. The Chinese version of Pittsburgh Sleep Quality Index (PSQI) and the short form of McGill Pain Questionnaire (SF-MPQ) was used to assess sleep quality and intensity of pain. Logistic regression was performed to test the association between sleeping quality and pain intensity.

Results

Two hundred and sixty-four patients with COPD, with an average age of 64 years (SD 5.78 years), were enrolled, and of 52% were women. Seventy-one (26.9%) participants reported at least one exacerbation during the past year. About 28.2% of the patients were classified as having poor sleep quality. Sleep quality was significantly associated with PRI score (adjusted odds ratio (ORad)=2.16, 95% CI: 1.16–4.00) and PPI rank (ORad=1.90, 95% CI: 1.08–3.34). People with daytime disturbance were more likely to have pain (ORad =2.03, 95% CI: 1.18–3.50).

Conclusion

Poor sleep quality was common in mild patients with COPD in community and was associated with higher pain intensity. Pain may involve an impairment of sleep quality.

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

Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are common chronic diseases. These two noncommunicable diseases (NCDs) are prevalent among approximately 10% of the general population. Approximately 1% of the population is affected by the co-existence of both conditions, known as the overlap syndrome (OS). OS patients suffer from greater degrees of nocturnal oxygen desaturation and cardiovascular consequences than those with either condition in isolation. Besides OS, patients with COPD may suffer from a spectrum of sleep-related breathing disorders, including hypoventilation and central sleep apnea. The article provides an overview of the pathogenesis, associated risk factors, prevalence, and management of sleep-related breathing disorders in COPD. It examines respiratory changes during sleep caused by COPD and OSA. It elaborates upon the factors that link the two conditions together to lead to OS. It also discusses the clinical evaluation and diagnosis of these patients. Subsequently, it reviews the pathophysiological basis and the current evidence for three potential therapies: positive airway pressure therapy [including continuous positive airway pressure (CPAP) and bilevel positive airway pressure], oxygen therapy, and pharmacological therapy. It also proposes a phenotypic approach toward the diagnosis and treatment of OS and the entire spectrum of sleep-related breathing disorders in COPD. It concludes with the current evidence gaps and future areas of research in the management of OS.

Comorbidities Associated With Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease or COPD is characterized by airflow obstruction, causing respiratory symptoms. There are treatments available for COPD; however, COPD has significant extrapulmonary effects, including well-recognized ones as cardiovascular disease and often underdiagnosed ones as osteoporosis. It is imperative to be aware of these comorbidities to optimize COPD patient care.

Symptomatic response to CPAP in obstructive sleep apnea versus COPD- obstructive sleep apnea overlap syndrome: Insights from a large national registry

Background

The symptomatic response to continuous positive airway pressure (CPAP) therapy in COPD-obstructive sleep apnea overlap syndrome (OVS) compared to OSA syndrome (OSA) alone has not been well studied so far. The aim of this study is to explore main differences in the clinical response to CPAP treatment in OVS compared to OSA alone.

Study design and methods

Using prospective data from the French National Sleep Apnea Registry, we conducted an observational study among 6320 patients with moderate-to-severe OSA, available spirometry, and at least one follow-up visit under CPAP therapy.

Results

CPAP efficacy measured on the residual apnea-hypopnea index and median adherence were similar between OVS and OSA patients. In both groups, the overall burden of symptoms related to sleep apnea improved with CPAP treatment. In a multivariable model adjusted for age, gender, body mass index, adherence to treatment and residual apnea-hypopnea index, OVS was associated with higher odds for persistent morning headaches (OR: 1.37 [95% CI; 1.04; 1.79]; P = 0.02), morning tiredness (OR: 1.33 [95% CI: 1.12; 1.59]; P<0.01), daytime sleepiness (OR; 1.24 [95% CI: 1.4; 1.46]: P<0.01) and exertional dyspnea (OR: 1.26 [95% CI: 1.00;1.58]; P = 0.04) when compared with OSA alone.

Interpretation

CPAP therapy was effective in normalizing the apnea-hypopnea index and significantly improved OSA-related symptoms, regardless of COPD status. CPAP should be offered to patients with OVS on a trial basis as a significant improvement in OSA-related symptoms can be expected, although the range of response may be less dramatic than in OSA alone.

The association between sleep quality, health status and disability due to breathlessness in chronic obstructive pulmonary disease patients

BACKGROUND

Chronic obstructive pulmonary disease (COPD) increases susceptibility to sleep disturbances. This study aimed to evaluate the association between COPD severity criteria with sleep quality.

METHODS

One hundred fifty-eight patients in Rasul Akram Hospital of Iran University of Medical Sciences, Tehran, Iran, from April 2019 to March 2021 diagnosed with COPD were examined using the Pittsburgh Sleep Quality Index (PSQI), COPD Assessment Test (CAT), modified Medical Research Council (mMRC) dyspnoea scale, spirometry and pulse oximetry.

RESULTS

Of 158 subjects, 125 patients were male (79%), and 33 were female (21%). The mean subject's age and FEV1/FVC ratio were 62.6 ± 11.5 and 65.6 ± 14.9%, respectively. The mean CAT scoring and Spo2 saturation reported 16.2 ± 7 and 91.5 ± 10.8%, respectively. The mean PSQI score was 8.2 ± 3.8. The association between PSQI score with FEV1 and FEV1/FVC ratio was not statistically significant (p = 0.64 and 0.58, respectively), whereas the association between PSQI scores with CAT score (p ˂ 0.0001, r²  = 0.51) and dyspnoea severity (p ˂ 0.0001, r²  = 0.29) were statistically significant. The patients with higher CAT score demonstrated poor sleep quality, particularly in longer sleep latency (p = 0.001, r²  = 0.056), bad subjective sleep quality (p ˂ 0.0001, r²  = 0.286), lower sleep efficiency (p = 0.002, r²  = 0.077), higher sleep disturbance (p ˂ 0.0001, r²  = 0.225), daytime dysfunction (p ˂ 0.0001, r²  = 0.259) and sleep medication intake times a week (p = 0.01, r²  = 0.069). Dyspnoea severity was attributed to bad subjective sleep quality (p ˂ 0.0001, r²  = 0.069), higher sleep disturbances (p = 0.005, r²  = 0.08), and daytime dysfunction (p ˂ 0.0001, r²  = 0.108).

CONCLUSION

The PSQI has a significant association with the CAT and mMRC for COPD patients and is linked to the disease's severity.

Sleep quality and architecture in COPD: the relationship with lung function abnormalities

OBJECTIVE

Impaired respiratory mechanics and gas exchange may contribute to sleep disturbance in patients with COPD. We aimed to assess putative associations of different domains of lung function (airflow limitation, lung volumes, and gas exchange efficiency) with polysomnography (PSG)-derived parameters of sleep quality and architecture in COPD.

METHODS

We retrospectively assessed data from COPD 181 patients ≥ 40 years of age who underwent spirometry, plethysmography, and overnight PSG. Univariate and multivariate linear regression models predicted sleep efficiency (total sleep time/total recording time) and other PSG-derived parameters that reflect sleep quality.

RESULTS

The severity of COPD was widely distributed in the sample (post-bronchodilator FEV1 ranging from 25% to 128% of predicted): mild COPD (40.3%), moderate COPD (43.1%), and severe-very severe COPD (16.6%). PSG unveiled a high proportion of obstructive sleep apnea (64.1%) and significant nocturnal desaturation (mean pulse oximetry nadir = 82.2% ± 6.9%). After controlling for age, sex, BMI, apnea-hypopnea index, nocturnal desaturation, comorbidities, and psychotropic drug prescription, FEV1/FVC was associated with sleep efficiency (β = 25.366; R2 = 14%; p < 0.001), whereas DLCO predicted sleep onset latency (β = -0.314; R2 = 13%; p < 0.001) and rapid eye movement sleep time/total sleep time in % (β = 0.085; R2 = 15%; p = 0.001).

CONCLUSIONS

Pulmonary function variables reflecting severity of airflow and gas exchange impairment, adjusted for some potential confounders, were weakly related to PSG outcomes in COPD patients. The direct contribution of the pathophysiological hallmarks of COPD to objectively measured parameters of sleep quality seems to be less important than it was previously assumed.

Machine learning for nocturnal diagnosis of chronic obstructive pulmonary disease using digital oximetry biomarkers

Objective.Chronic obstructive pulmonary disease (COPD) is a highly prevalent chronic condition. COPD is a major cause of morbidity, mortality and healthcare costs globally. Spirometry is the gold standard test for a definitive diagnosis and severity grading of COPD. However, a large proportion of individuals with COPD are undiagnosed and untreated. Given the high prevalence of COPD and its clinical importance, it is critical to develop new algorithms to identify undiagnosed COPD. This is particularly true in specific disease groups in which the presence of concomitant COPD increases overall morbidity/mortality such as those with sleep-disordered breathing. To our knowledge, no research has looked at the feasibility of automated COPD diagnosis using a data-driven analysis of the nocturnal continuous oximetry time series. We hypothesize that patients with COPD will exert certain patterns and/or dynamics of their overnight oximetry time series that are unique to this condition and that may be captured using a data-driven approach.Approach.We introduce a novel approach to nocturnal COPD diagnosis using 44 oximetry digital biomarkers and five demographic features and assess its performance in a population sample at risk of sleep-disordered breathing. A total ofn=350 unique patients' polysomnography (PSG) recordings were used. A random forest (RF) classifier was trained using these features and evaluated using nested cross-validation.Main results.The RF classifier obtainedF1 = 0.86 ± 0.02 and AUROC = 0.93 ± 0.02 on the test sets. A total of 8 COPD individuals out of 70 were misclassified. No severe cases (GOLD 3-4) were misdiagnosed. Including additional non-oximetry derived PSG biomarkers resulted in minimal performance increase.Significance.We demonstrated for the first time, the feasibility of COPD diagnosis from nocturnal oximetry time series for a population sample at risk of sleep-disordered breathing. We also highlighted what set of digital oximetry biomarkers best reflect how COPD manifests overnight. The results motivate that overnight single channel oximetry can be a valuable modality for COPD diagnosis, in a population sample at risk of sleep-disordered breathing. Further data is needed to validate this approach on other population samples.

Sleep Disturbance, Sleep Disorders and Co-Morbidities in the Care of the Older Person

Sleep complaints can be both common and complex in the older patient. Their consideration is an important aspect of holistic care, and may have an impact on quality of life, mortality, falls and disease risk. Sleep assessment should form part of the comprehensive geriatric assessment. If sleep disturbance is brought to light, consideration of sleep disorders, co-morbidity and medication management should form part of a multifaceted approach. Appreciation of the bi-directional relationship and complex interplay between co-morbidity and sleep in older patients is an important element of patient care. This article provides a brief overview of sleep disturbance and sleep disorders in older patients, in addition to their association with specific co-morbidities including depression, heart failure, respiratory disorders, gastro-oesophageal reflux disease, nocturia, pain, Parkinson's disease, dementia, polypharmacy and falls. A potential systematic multidomain approach to assessment and management is outlined, with an emphasis on non-pharmacological treatment where possible.

Physiological sleep measures predict time to 15-year mortality in community adults: Application of a novel machine learning framework

Clarifying whether physiological sleep measures predict mortality could inform risk screening; however, such investigations should account for complex and potentially non-linear relationships among health risk factors. We aimed to establish the predictive utility of polysomnography (PSG)-assessed sleep measures for mortality using a novel permutation random forest (PRF) machine learning framework. Data collected from the years 1995 to present are from the Sleep Heart Health Study (SHHS; n = 5,734) and the Wisconsin Sleep Cohort Study (WSCS; n = 1,015), and include initial assessments of sleep and health, and up to 15 years of follow-up for all-cause mortality. We applied PRF models to quantify the predictive abilities of 24 measures grouped into five domains: PSG-assessed sleep (four measures), self-reported sleep (three), health (eight), health behaviours (four), and sociodemographic factors (five). A 10-fold repeated internal validation (WSCS and SHHS combined) and external validation (training in SHHS; testing in WSCS) were used to compute unbiased variable importance metrics and associated p values. We observed that health, sociodemographic factors, and PSG-assessed sleep domains predicted mortality using both external validation and repeated internal validation. The PSG-assessed sleep efficiency and the percentage of sleep time with oxygen saturation <90% were among the most predictive individual measures. Multivariable Cox regression also revealed the PSG-assessed sleep domain to be predictive, with very low sleep efficiency and high hypoxaemia conferring the highest risk. These findings, coupled with the emergence of new low-burden technologies for objectively assessing sleep and overnight oxygen saturation, suggest that consideration of physiological sleep measures may improve risk screening.

The prevalence and impact of pre-existing sleep disorder diagnoses and objective sleep parameters in patients hospitalized for COVID-19

STUDY OBJECTIVES

Obstructive sleep apnea and other sleep disorders overlap with comorbidities associated with poor outcomes related to severe acute respiratory syndrome coronavirus 2 infection. However, the prevalence of obstructive sleep apnea among patients hospitalized for COVID-19 and relationship to outcomes is poorly characterized, and the relevance of other sleep disorders remains unknown. The objective of this study was to identify the prevalence of pre-existing sleep disorders and association with outcomes related to severe COVID-19 illness.

METHODS

Patients with severe acute respiratory syndrome coronavirus 2 infection admitted to the University of Michigan Hospital System were included. Electronic medical records were queried for sleep disorders diagnostic codes. Data were extracted from polysomnography and home sleep testing in a subgroup with previous diagnostic testing at our center. Logistic regression was used to examine the association of sleep disorders with mechanical ventilation requirement, treatment with vasopressors, and death and Cox proportional hazards regression for time to discharge.

RESULTS

Among n = 572 adult patients hospitalized for COVID-19, 113 (19.8%) patients had obstructive sleep apnea, 4 patients had central sleep apnea (0.7%), 5 had hypoventilation (0.9%), 63 had insomnia (11.0%), and 22 had restless legs syndrome or periodic limb movements disorder (3.9%). After adjusting for age, sex, body mass index, and race, no significant relationship was apparent between sleep disorders diagnoses or indices of sleep-disordered breathing severity and outcomes.

CONCLUSIONS

This is the first study to determine the prevalence of obstructive sleep apnea and other sleep disorders in a well-characterized cohort of patients hospitalized for COVID-19. Once hospitalized, a significant contribution of sleep disorders to outcomes was not identified. Therefore, future evaluations should focus on earlier outcomes, such as infection or clinical manifestations after exposure to severe acute respiratory syndrome coronavirus 2.

The Maugeri daily activity profile: a tool to assess physical activity in patients with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) report reduced physical activity (PA). There are only few tools available to assess PA and sedentary behavior in these patients, and none of them aims to differentiate between sedentary and active patterns. The aim of the study was to evaluate an easy tool to profile daily activity time in a cohort of patients with COPD, compared to healthy subjects; the study was set at the Istituti Clinici Scientifici Maugeri (ICS), IRCCS of Tradate and Lumezzane, Italy, and at the Ente Ospedaliero Cantonale Novaggio, Switzerland (Italian Speaking). The populations were inpatients with COPD, healthy subjects. The items of the Maugeri Daily Activity (MaDA) profile were chosen based on literature, interviews with patients and health professionals. Time spent during sleep (ST), when awake (AT), active (ACT) or in sedentary behavior (SET) were recorded. Lung function tests, arterial blood gases, the modified Medical Research Council (mMRC), the six-minute walking distance test (6MWD), the COPD Assessment Test (CAT), and the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index were also assessed in patients. Sixty patients with COPD and 60 healthy controls filled in the questionnaire. As compared to controls, patients showed longer AT and SET. Active time of patients was significantly correlated with mMRC, CAT, Bode Index and 6MWD, but not with demographics, anthropometrics or stages of disease. Using this tool, we found that patients with COPD spent longer time awake and in sedentary behavior. The MaDA may be useful to evaluate PA in patients with COPD.

Effect of chronic non-communicable diseases (CNCDs) on the sleep of Brazilians during the COVID-19 pandemic

This study aimed to investigate the effect of Chronic Noncommunicable Diseases (CNCDs) on the onset or increase in sleep problems during the COVID-19 pandemic period. The role of the report of sadness or nervousness during the pandemic was also evaluated as a mediator of this association. Data from a behavior survey during COVID-19, conducted in Brazil with 45,161 people (18 years old or older), from April 24 to May 24, 2020, were used. The outcome variable was the onset or increase in sleep problems, and the exposure variable was the presence of CNCDs. The adjusted Odds Ratio of the association between CNCDs and sleep was estimated, and a mediation analysis was performed to test the effect of the report of sadness or nervousness on this association, using the Karlson Holm Breen method. The increase in sleep problems was reported by 44.9% of the population, and 33.9% reported at least one CNCD. The chance of sleep problems was higher among people with diabetes (1.34; 1.05–1.71), hypertension (1.26; 1.06–1.50), and with coronary heart diseases (1.36; 1.13–1.65) or respiratory diseases (1.42; 1.04–1.93). Compared to people without CNCDs, individuals with at least one CNCD had a 36% greater chance of impaired sleep (1.36; 1.19–1.55). The report of sadness or nervousness explained 45.1% of the association between CNCD and sleep. Our findings alert us to care for the emotional state and sleep of chronic patients during the waves of the COVID-19 pandemic, and indicate the need for sleep monitoring in this population.

Impact of insomnia and obstructive sleep apnea on the risk of acute exacerbation of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major health burden worldwide. Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is characterized by worsening of patients' respiratory symptoms that requires a modification in medication. This event could accelerate disease progression and increase the risk of hospital admissions and mortality. Both insomnia and obstructive sleep apnea (OSA) are prevalent in patients with COPD, and are linked to increased susceptibility to AECOPD. Improper treatment of insomnia may increase the risk of adverse respiratory outcomes for patients with COPD, while effective continuous positive airway pressure (CPAP) treatment may reduce the risk of AECOPD and mortality in patients with overlap syndrome. Sleep disorders should be considered in clinical management for COPD.