Overlap syndrome of COPD and OSA in Koreans

Estimating the prevalence and clinical significance of chronic obstructive pulmonary disease-obstructive sleep apnea overlap in South Korea

INTRODUCTION

Concurrent obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are referred to as COPD-OSA overlap. We investigated the prevalence and clinical significance of COPD-OSA overlap in the general population of South Korea.

METHODS

Data were obtained from the 2019 Korea National Health and Nutrition Examination Survey. Participants ≥40 years of age with complete STOP-Bang questionnaire and spirometry data were included. OSA was presumed in individuals with a STOP-Bang score of ≥3. COPD was determined using forced expiratory volume at 1 s/forced vital capacity <0.7. Participants were classified on the basis of the STOP-Bang score and spirometry findings. Clinical characteristics, comorbidities, and quality of life (using the EuroQoL 5-dimension instrument) were compared between the overlap group and COPD-alone or OSA-alone groups.

RESULTS

Among the 3157 participants, 6.9 % demonstrated COPD-OSA overlap. Individuals with OSA alone and COPD alone were 31.8 % and 5.2 %, respectively. The overlap group included more males, ever smokers, and frequent alcohol drinkers than the COPD- or OSA-alone groups. The overlap group had more diagnoses of hypertension, diabetes, and stroke than the COPD-alone group. The risk of anxiety/depression was approximately 2.5 times higher in the overlap group than in the COPD-alone group. COPD-OSA overlap was a significant risk factor for anxiety/depression after adjusting for age, sex, household income, and education levels.

CONCLUSION

COPD-OSA overlap is not rare within the general population of South Korea. Patients with overlap showed more comorbidities and higher levels of anxiety/depression than those in the COPD-alone group.

30-Day Postoperative Outcomes in Adults with Obstructive Sleep Apnea Undergoing Upper Airway Surgery

Background: Obstructive sleep apnea (OSA) is a chronic disorder of the upper airway. OSA surgery has oftentimes been researched based on the outcomes of single-institutional facilities. We retrospectively analyzed a multi-institutional national database to investigate the outcomes of OSA surgery and identify risk factors for complications. Methods: We reviewed the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2008−2020) to identify patients who underwent OSA surgery. The postoperative outcomes of interest included 30-day surgical and medical complications, reoperation, readmission, and mortality. Additionally, we assessed risk-associated factors for complications, including comorbidities and preoperative blood values. Results: The study population included 4662 patients. Obesity (n = 2909; 63%) and hypertension (n = 1435; 31%) were the most frequent comorbidities. While two (0.04%) deaths were reported within the 30-day postoperative period, the total complication rate was 6.3% (n = 292). Increased BMI (p = 0.01), male sex (p = 0.03), history of diabetes (p = 0.002), hypertension requiring treatment (p = 0.03), inpatient setting (p < 0.0001), and American Society of Anesthesiology (ASA) physical status classification scores ≥ 4 (p < 0.0001) were identified as risk-associated factors for any postoperative complications. Increased alkaline phosphatase (ALP) was identified as a risk-associated factor for the occurrence of any complications (p = 0.02) and medical complications (p = 0.001). Conclusions: OSA surgery outcomes were analyzed at the national level, with complications shown to depend on AP levels, male gender, extreme BMI, and diabetes mellitus. While OSA surgery has demonstrated an overall positive safety profile, the implementation of these novel risk-associated variables into the perioperative workflow may further enhance patient care.

Mortality prediction in chronic obstructive pulmonary disease and obstructive sleep apnea

BACKGROUND

We aimed to assess mortality in chronic obstructive pulmonary disease (COPD), obstructive sleep apnea (OSA), and overlap syndrome, and evaluate which polysomnographic indices-apnea-hypopnea index (AHI) or hypoxemic load measurements-better predict mortality within 10 years.

METHODS

Adults with symptoms suggestive of sleep apnea and airway disease who underwent both polysomnography and spirometry plus bronchodilator response tests between 2000 and 2018 were included and divided into four groups according to presence of COPD and moderate-to-severe OSA (AHI ≥15/h). We estimated mortality using a Cox model adjusted for demographic/anthropometric covariates and comorbidities; this was called clinical model. To evaluate prognostic performance, we compared the concordance index (C-index) between clinical model and extended models, which incorporated one of polysomnographic indices-AHI, sleep time spent with SpO₂ < 90% (TS90), and mean and lowest SpO₂.

RESULTS

Among 355 participants, patients with COPD alone (57/355, 16.1%) and COPD-OSA overlap syndrome (37/355, 10.4%) had increased all-cause mortality than those who had neither disease (152/355, 42.8%) (adjusted HR, 2.98 and 3.19, respectively). The C-indices of extended models with TS90 (%) and mean SpO₂ were significantly higher than that of clinical model (0.765 vs. 0.737 and 0.756 vs. 0.737, respectively; all P < 0.05); however, the C-index of extended model with AHI was not (0.739 vs. 0.737; P = 0.15).

CONCLUSIONS

In this cohort with symptoms of sleep apnea and airway disease, patients with overlap syndrome had increased mortality, but not higher than in those with COPD alone. The measurement of hypoxemic load, not AHI, better predicted mortality.

Co-existing obstructive sleep apnea among patients with chronic obstructive pulmonary disease

Background and Objectives:

Chronic obstructive pulmonary disease (COPD) is a common airway disease that is frequently associated with comorbidities. In this study, we assessed the co-existence of obstructive sleep apnea (OSA) among patients with stable COPD.

Methodology:

This cross-sectional study included patients with stable COPD who were screened with Epworth's Sleepiness Scale (ESS). Those with ESS score of >10 were subjected to in-lab polysomnography (PSG). PSG was manually analyzed and reported. Patients with apnea–hypopnea index of >5/h were diagnosed as OSA.

Results:

This study included 301 patients (78.1% male, 76.4% smokers, age 59.6 ± 10 years) with stable COPD. ESS score of >10 was observed in 47 (15.6%) patients. Among patients with ESS score of >10, OSA was observed in 34 (72.3%) patients. The overall prevalence of OSA among patients with COPD was 10.9%. Patients with co-existing OSA were older and had thicker neck and higher body mass index (BMI) as compared to COPD alone. In addition, patients with associated OSA had worse health-related quality of life (QOL) as shown by higher St. George's Respiratory Questionnaire score (42.42 ± 7.22 vs. 25.22 ± 8.66; P < 0.001).

Conclusions:

Co-existing OSA is common among patients with COPD and has a significant adverse effect on the QOL. Among COPD patients, older age, thick neck, and high BMI may predict co-existing OSA and require PSG for the confirmation.

Obstructive Sleep Apnea Increases the Prevalence of Hypertension in Patients with Chronic Obstructive Disease

Whether there are increased rates of chronic diseases associated with the combination of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) overlap syndrome (OVS) has not been determined. The purpose of this study was to assess the prevalence of five comorbidities in COPD and OVS patients. A total of 968 patients with confirmed COPD were included in this study. Participants were requested to fill out a questionnaire involving their basic information and medical history. All subjects underwent one overnight polysomnography and were then divided into an OVS group or a COPD only group according to their apnea-hypopnea index. The prevalence of hypertension, diabetes, cardiovascular disease, arrhythmia and cerebrovascular disease were compared and risk factors for comorbidities in COPD patients were identified. Compared with the COPD only group, the prevalence of hypertension was significantly higher in the OVS group, however, the prevalence rates of the other four kinds of diseases were not statistically different between the two groups. In COPD patients, the prevalence of hypertension increased with the severity of OSA and the prevalence of arrhythmia increased with airflow limitation severity. Risk factors for OSA in patients with COPD included BMI, FEV₁%, Epworth Sleepiness Scale score and the Sleep Apnea Clinical Score. OSA was an independent risk factor for hypertension. The other risk factors for hypertension in COPD patients included age, BMI, CAT score and alcohol consumption. Age, lower FEV₁% may be risk factors for arrhythmia. OVS patients were associated with a high prevalence rate of hypertension, while OSA was an independent risk factor for hypertension.

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

Background

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

Main body of abstract

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

Conclusion

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

Oropharyngeal Microbiome in Obstructive Sleep Apnea: Decreased Diversity and Abundance

STUDY OBJECTIVES

To explore and analyze diversity and abundance of oropharyngeal microbiota in patients with obstructive sleep apnea (OSA).

METHODS

This was a cross-sectional study. Middle-aged men, suspected to have OSA, referred to full-night polysomnography, and willing to provide oropharyngeal swab samples, were consecutively enrolled. OSA severity was assessed by apnea-hypopnea index (AHI) as non-OSA (AHI < 5 events/h) and OSA (AHI ≥ 15 events/h). Bacterial DNA of oropharyngeal samples was extracted and quality test performed. Oropharyngeal microbiota was analyzed using 16S ribosomal DNA (rDNA) sequencing, and bioinformatic analysis carried out after sequencing.

RESULTS

Samples from 51 men (25 in the non-OSA group and 26 in the OSA group) were sent for examination. Of these, 40 samples were found to have sufficient concentration of DNA and were analyzed for bioinformatics. In alpha diversity analysis, the OSA group exhibited significantly lower sobs (198.33 ± 21.71 versus 216.57 ± 26.21, P = .022), chao (221.30 ± 26.62 versus 243.86 ± 26.20, P = .014), ace (222.17 ± 27.15 versus 242.42 ± 25.81, P = .028) and shannon index (3.14 ± 0.23 versus 3.31 ± 0.26, P = .035), suggesting a reduction in microbial species diversity. We further divided participants into non-OSA, moderate OSA, and severe OSA groups and observed a significant decrease in the bacterial biodiversity of OSA groups compared with the non-OSA group, with the most significant decrease occurring in the moderate OSA group. Principal coordinate analysis showed two extremely different oropharyngeal microbial communities in non-OSA and OSA groups. More interestingly, proportion of Neisseria was slightly higher in the severe OSA group (20.64%), followed by the moderate OSA and non-OSA groups (12.57% and 9.69%, respectively). Glaciecola was not detected in the OSA groups compared to the non-OSA group (0 versus 0.772 ± 0.4754, P < .001).

CONCLUSIONS

Middle-aged men with OSA showed less oropharyngeal species diversity and altered abundance, on which further confirmation is warranted.