Moderate-to-Severe Obstructive Sleep Apnea and Cognitive Function Impairment in Patients with COPD

Chronic Obstructive Pulmonary Disease and Obstructive Sleep Apnea Overlap Syndrome: An Update on the Epidemiology, Pathophysiology, and Management

This review provides an up-to-date summary of the prevalence, pathophysiology, diagnosis, and treatment of the chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) overlap syndrome (OVS). The presence of OVS is high in patients with COPD and in patients with OSA and is associated with profound nocturnal oxygen desaturation and systemic inflammation. There is a high prevalence of cardiovascular disease among patients with OVS and this likely contributes to increased mortality. Observational studies suggest that positive airway pressure therapy improves survival and reduces COPD exacerbations; however, randomized controlled trials will be required to confirm these findings.

Sleep disordered breathing: OSA-COPD overlap

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Evaluation of nocturnal apnea and airflow limitation as indicators for cognitive dysfunction in patients with chronic obstructive pulmonary disease/obstructive sleep apnea hypopnea syndrome overlap syndrome

OBJECTIVE

The aim of this study is to investigate how much intermittent hypoxemia and airflow limitation contribute to cognitive impairment in overlap syndrome (OS), which is the coexistence of two common diseases, obstructive sleep apnea hypopnea syndrome (OSAHS) and chronic obstructive pulmonary disease (COPD).

METHODS

We conducted a cross-sectional study of patients with OSAHS, COPD or OS, compared with normal controls, to determine the association between sleep apnea/pulmonary function-related indicators and cognitive dysfunction in individuals with OSAHS, COPD or OS.

RESULTS

A total of 157 participants were recruited. Both OSAHS and OS presented lower adjusted Montreal cognitive assessment (MoCA) scores compared with COPD group. In addition, the MoCA score was significantly lower in COPD group compared with control group. The incidence of cognitive impairment was 57.4% in OSAHS group, and 78% in OS group, which were significantly higher than COPD group (29%) and control group (8.8%). Furthermore, a broader range of cognitive domains were affected in OS group compared with OSAHS group. Elevated levels of oxygen desaturation index (ODI) and/or apnea hypopnea index (AHI) were positively correlated with increased Epworth sleeping scale (ESS) in OSAHS and OS. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) were positively correlated with cognitive scores in OSAHS but not in OS. Serum level of hypoxia-inducible factor-1α (HIF-1α) was significantly higher in OS. Logistic regression identified ODI as an independent risk factor for cognitive impairment in OS, while severity of snoring and PEF were independent risk factors in OSAHS.

DISCUSSION

This study revealed significant cognitive impairment in OS, OSAHS and COPD. Sleep-related indicators are warranted in OS patients for detection, differentiation and grading of cognitive impairment, whereas pulmonary functions are warranted in OSAHS patients for detection and early intervention of cognitive impairment.

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.

Association between cardiopulmonary function, health-related quality of life and cognitive impairment among the older nursing home residents in Shanghai, China

BACKGROUND

This study aimed to examine the association between cardiopulmonary function, health-related quality of life (HRQOL) and cognitive function among nursing home residents aged 80 years and over.

METHODS

A nursing home-based, cross-sectional study was implemented among 677 aged over 80 years in Shanghai, China. A total of 197 participants underwent effective cardiopulmonary function examinations. Mini-Mental Status Examination (MMSE) and Short Form-36 scales (SF-36) were used to assess cognitive function and HRQOL, respectively.

RESULTS

Decline in left ventricular ejection fractions (LVEF) [adjusted odds ratio (AOR), 1.98; 95% confidential interval (CI), 1.03-3.81)] and vital capacity (VC) (AOR, 2.08; 95%CI, 1.07-4.04) was associated with cognitive impairment. After adjusting confounding factors, relationships between cognitive function and physical functioning (PF) (AOR, 0.98; 95%CI, 0.97-0.99) still existed.

CONCLUSIONS

Healthcare professionals should pay more attention to cardiopulmonary health and HRQOL in the nursing home residents. Actions of public health strategies focus on the improvement of cardiopulmonary function, and PF among older nursing home residents with cognitive impairment is required.

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

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are common diseases that strongly impact the quality and length of life. Their coexistence is determined by overlap syndrome (OS). This systematic review aims to define the significance of these comorbidities according to the current state of knowledge. For this systematic review, we searched PubMed, Scopus, and Cochrane for studies published between 2018 and 26 October 2022, to find original, observational, human studies published in English, where the diagnosis of COPD was according to the Global Initiative for Obstructive Lung Disease guidelines and the diagnosis of OSA was based on polysomnography. The quality of studies was assessed using the Newcastle-Ottawa quality assessment tool for cohort and case-control studies, as well as its modification for cross-sectional studies. Of the 1548 records identified, 38 were eligible and included in this systematic review. The included studies covered a total population of 27,064 participants. This paper summarizes the most important, up-to-date information regarding OS, including the prevalence, meaning of age/gender/body mass index, polysomnography findings, pulmonary function, comorbidities, predicting OSA among COPD patients, and treatment of this syndrome.

Effect of Sleep Disturbance on Cognitive Function in Elderly Individuals: A Prospective Cohort Study

Many epidemiologic and clinical studies have shown significant links between the degree of sleep disturbance and severity of impairment of selective cognitive functions, including the risk of neurodegenerative diseases. However, the sleep parameters that affect cognitive function in old age are unclear. Therefore, we investigated the association between sleep parameters and cognitive function in older patients. Patients aged above 65 years who complained of sleep-disordered breathing were enrolled consecutively. The Mini-Mental-State Examination tool was used to evaluate cognitive function. Eighty patients (normal cognitive function, n = 32 and cognitive impairment, n = 42) were included in this study. Multiple linear regression and binary logistic regression analyses were performed to explain the relationship between sleep parameters and cognitive function. We found that the body mass index (BMI) was significantly lower in the cognitive impairment group than in the normal cognitive function group. Additionally, the cognitive impairment group showed significantly decreased sleep efficiency and an increased apnea index compared with normal subjects. Moreover, lower BMI, reduced sleep efficiency, and high frequency of apnea events during sleep were associated with an increased risk of cognitive impairment.

Assessment of the cognitive function in adult Egyptian patients with obstructive sleep apnea using the Montreal Cognitive Assessment: a retrospective large-scale study

STUDY OBJECTIVES

Sleep apnea is a chronic disorder associated with multiple recognized comorbidities. Only a few studies focus on evaluating the cognitive profile in patients diagnosed with sleep apnea. The aim of the study was to assess the cognitive functions in this population using the Montreal Cognitive Assessment.

METHODS

The study cohort was 1,445 adult patients who were referred for overnight polysomnography, 764 cases and 681 healthy controls. All participants' clinical data and comorbidities were taken, and they all performed overnight polysomnography and Montreal Cognitive Assessment.

RESULTS

A significantly higher proportion (57.5%) of sleep apnea groups were males; 15.7% were illiterate compared to the non-sleep apnea group. Hypertension and diabetes mellitus were significantly more prevalent among studied patients with sleep apnea, and the mean total score for the Montreal Cognitive Assessment scale was significantly lower among those with sleep apnea at P < .001. Those with no sleep apnea showed a significantly higher function in all attributes compared to patients with sleep apnea-namely, language, orientation, abstraction, naming, attention, and recall (P < .05).

CONCLUSIONS

Logistic regression analysis was conducted to investigate predictors for occurrence of cognitive impairment (Montreal Cognitive Assessment score < 26) among the studied sample (n = 1,445). The overall model was significant at P < .001. Variables that showed significance in univariate analysis were entered in the model. Significant predictors for cognitive impairment were being male, older age, diabetic, hypertensive, and with a lower level of education and having sleep apnea.

CITATION

Mekky JF, Yousof S, Elsayed I, Elsemelawy R, Mahmoud H, Elweshahi H. Assessment of the cognitive functions in adult Egyptian patients with obstructive sleep apnea using the Montreal Cognitive Assessment: a retrospective large-scale study. J Clin Sleep Med. 2022;18(3):721-729.

Diagnostic and therapeutic challenges of chronic obstructive pulmonary disease in the elderly

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) imposes a large burden on the global population and even more so for the elderly who face significant obstacles in the diagnosis, management, and psychosocial effects of the disease. This review describes the current challenges and key points in the management of COPD in the elderly.

RECENT FINDINGS

Lower limit rather than fixed cut off of the FEV1/FVC ratio can improve the diagnosis and better predict COPD mortality. High relative to standard dose influenza vaccination reduces confirmed cases of influenza overall and reduces hospitalizations in older nursing home residents. Simple interventions that include electronic health record tracking can significantly improve vaccination rates. Although many inhaler and nebulized medications are available for the elderly, the final regimen is usually determined by a combination of expense, issues with proper device use (from difficulty with coordination, hand grip, inspiratory flows or cognitive function) and the side effect profile. Fortunately, the switch to cheaper or better covered alternatives can be well tolerated with improvement in adherence and exacerbations of COPD. Finally, caution should be made against ageism, which may be a factor in the recommendation of rehabilitation or palliative care in the elderly COPD patient, as both are underused despite evidence of benefit.

SUMMARY

Although care for the elderly COPD patient can be difficult, we summarize key points that the physician should be cognizant of to provide comprehensive care.

Oxygen desaturation during flexible bronchoscopy with propofol sedation is associated with sleep apnea: the PROSA-Study

BACKGROUND

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial obstruction of the upper airways during sleep. Conscious sedation for flexible bronchoscopy (FB) places patients in a sleep-like condition. We hypothesize that oxygen desaturation during flexible bronchoscopy may help to detect undiagnosed sleep apnea.

METHODS

Single-centre, investigator-initiated and driven study including consecutive patients undergoing FB for clinical indication. Patients completed the Epworth Sleepiness Scale (ESS), Lausanne NoSAS score, STOP-BANG questionnaire and the Berlin questionnaire and underwent polygraphy within 7 days of FB. FB was performed under conscious sedation with propofol. Oxygen desaturation during bronchoscopy was measured with continuous monitoring of peripheral oxygen saturation with ixTrend (ixellence GmbH, Germany).

RESULTS

145 patients were included in the study, 62% were male, and the average age was 65.8 ± 1.1 years. The vast majority of patients (n = 131, 90%) proved to fulfill OSA criteria based on polygraphy results: 52/131 patients (40%) had mild sleep apnea, 49/131 patients (37%) moderate sleep apnea and 30/131 patients (23%) severe sleep apnea. Patients with no oxygen desaturation had a significantly lower apnea-hypopnea index than patients with oxygen desaturation during bronchoscopy (AHI 11.94/h vs 21.02/h, p = 0.011). This association remained significant when adjusting for the duration of bronchoscopy and propofol dose (p = 0.023; 95% CI 1.382; 18.243) but did not hold when also adjusting for age and BMI.

CONCLUSION

The severity of sleep apnea was associated to oxygen desaturation during flexible bronchoscopy under conscious sedation. Patients with oxygen desaturation during bronchoscopy might be considered for sleep apnea screening.

TRIAL REGISTRATION

The Study was approved by the Ethics Committee northwest/central Switzerland, EKNZ (EK 16/13) and was carried out according to the Declaration of Helsinki and Good Clinical Practice guidelines. Due to its observational character, the study did not require registration at a clinical trial registry.