Effects of Coexisting Asthma and Obstructive Sleep Apnea on Sleep Architecture, Oxygen Saturation, and Systemic Inflammation in Women

Do nocturnal asthma attacks influence sleep parameters and inflammatory markers? A cross-sectional population-based study

PURPOSE

To evaluate the effects of nocturnal asthma on sleep parameters and inflammatory markers according to the severity of the condition in participants in the São Paulo Epidemiologic Sleep Study (EPISONO).

METHODS

Data from the 2007 and 2018 editions of the EPISONO study were utilized. Subjects completed validated sleep and respiratory questionnaires, underwent nocturnal polysomnography and spirometry tests, and provided blood samples for the assessment of inflammatory parameters.

RESULTS

Of 72 participants (67% women), 53% (n = 38) had intermittent nocturnal asthma symptoms and 47% (n = 34) had persistent asthma (mild, moderate, and severe). Individuals with persistent nocturnal symptoms had a higher body mass index (BMI), were more likely to have respiratory symptoms, and had worse lung function, a higher apnea-hypopnea index (AHI), and higher desaturation index than individuals with intermittent nocturnal symptoms. Positive associations were identified between nocturnal asthma and obstructive sleep apnea (OSA). A higher frequency of OSA was observed in participants with persistent asthma and participants with OSA were more likely to have persistent than intermittent asthma. However, there were no significant differences between the immunological parameters of those with intermittent or persistent asthma.

CONCLUSIONS

This study highlights the relevance of nocturnal symptoms as a valuable indicator of asthma severity. The findings also add to the existing body of evidence linking nocturnal asthma and OSA.

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 knowledge and attitudes towards pediatric obstructive sleep apnea and dental specialty

OBJECTIVE

To associate the knowledge and attitudes about Pediatric Obstructive Sleep Apnea (POSA) with the specialty of dentists in Metropolitan Lima, Peru.

METHODS

A cross-sectional, analytical observational study was carried out during 2021-2022. Two hundred and ten orthodontists and pediatric dentists were surveyed using the adapted and validated Spanish translation of the OSAKA-KIDS questionnaire and additional sociodemographic questions.

RESULTS

The data indicated an association between dental specialty and the professional's knowledge about POSA. Orthodontists were 59% less likely to have acceptable knowledge, compared to pediatric dentists (p = .013, IC 95% 0.21-0.83). The study revealed an association between the professional's attitudes and three intervening variables: age (p = .025), clinical experience (p = .049) and sector of practice (p = .020).

CONCLUSION

Knowledge was associated with the dental specialty of professionals in the sample included, whilst attitudes were not.

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

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

The relationship between obstructive sleep apnea and asthma severity and vice versa: a systematic review and meta-analysis

BACKGROUND

There is a great association between the prevalence of obstructive sleep apnea (OSA) and asthma. Nonetheless, whether OSA impacts lung function, symptoms, and control in asthma and whether asthma increases the respiratory events in OSA are unknown. This meta-analysis aimed to examine the relationship between obstructive sleep apnea and asthma severity and vice versa.

METHODS

We carried out a systematic search of PubMed, EMBASE, and Scopus from inception to September 2022. Primary outcomes were lung function, parameters of polysomnography, the risk of OSA in more severe or difficult-to-control asthmatic patients, and the risk of asthma in patients with more severe OSA. Heterogeneity was examined with the Q test and I² statistics. We also performed subgroup analysis, Meta-regression, and Egger's test for bias analysis.

RESULTS

34 studies with 27,912 subjects were totally included. The results showed that the comorbidity of OSA aggravated lung function in asthmatic patients with a consequent decreased forced expiratory volume in one second %predicted (%FEV1) and the effect was particularly evident in children. %FEV1 tended to decrease in adult asthma patients complicated with OSA, but did not reach statistical significance. Interestingly, the risk of asthma seemed to be slightly lower in patients with more severe OSA (OR = 0.87, 95%CI 0.763-0.998). Asthma had no significant effect on polysomnography, but increased daytime sleepiness assessed by the Epworth Sleepiness Scale in OSA patients (WMD = 0.60, 95%CI 0.16-1.04). More severe asthma or difficult-to-control asthma was independently associated with OSA (odds ratio (OR) = 4.36, 95%CI 2.49-7.64).

CONCLUSION

OSA was associated with more severe or difficult-to-control asthma with decreased %FEV₁ in children. The effect of OSA on lung function in adult patients should be further confirmed. Asthma increased daytime sleepiness in OSA patients. More studies are warranted to investigate the effect of asthma on OSA severity and the impact of different OSA severity on the prevalence of asthma. It is strongly recommended that people with moderate-to-severe or difficult-to-control asthma screen for OSA and get the appropriate treatment.

Asthma and asthma-related comorbidity: effects on nocturnal oxygen saturation

STUDY OBJECTIVES

Nocturnal symptoms are very common in asthma, which is associated with worse sleep quality. The nocturnal oxygen saturation may be decreased in asthma; however, whether this association is dependent on nocturnal asthma symptoms, lung function, coexisting obstructive sleep apnea (OSA), or other asthma-related comorbidities is unknown. The objective of this study was to examine the effects of asthma, OSA, lung function, airway symptoms, and asthma-related comorbidities on the nocturnal oxygen saturation in a cross-sectional community-based population study.

METHODS

In total, 395 women and 392 men underwent overnight polysomnography, performed spirometry, and completed questionnaires on airway symptoms and asthma-related comorbidities.

RESULTS

Participants with asthma (n = 88) had a lower nocturnal oxygen saturation than those without asthma (93.8% vs 94.3%, P = .01) also after adjusting for comorbidity, age, body mass index, and smoking status (coefficient -0.38; CI -0.67, -0.10; P < .01). The nocturnal oxygen saturation was lower among participants with wheezing, nocturnal chest tightness, fixed airflow limitation, gastroesophageal reflux, obesity, and OSA than in those without these conditions. The associations between lower oxygen saturation and wheezing, forced expiratory volume in 1 second, gastroesophageal reflux, and apnea-hypopnea index were significant also after adjusting for age, sex, body mass index, and smoking status. Participants with both wheezing and OSA had a significantly lower nocturnal oxygen saturation (92.5 ± 0.5%) than participants with wheezing only (94.3 ± 0.3%) and OSA only (93.6 ± 0.2% %) (P < .01).

CONCLUSIONS

Participants with asthma displayed a lower mean oxygen saturation during sleep, which could not be explained only by coexisting OSA or obesity. Also, asthma symptoms and lung function were associated with lower nocturnal oxygen saturation. The lower oxygen saturation seen in asthma is hence multifactorial in origin and is a result of the combination of symptoms, lung function, and comorbidity.

CITATION

Sundbom F, Janson C, Ljunggren M, Lindberg E. Asthma and asthma-related comorbidity: effects on nocturnal oxygen saturation. J Clin Sleep Med. 2022;18(11):2635-2641.

The Association between Asthma and OSA in Children

Obstructive sleep apnea (OSA) and asthma are two of the most prevalent and commonly co-existing respiratory conditions seen in the pediatric population. Studies linking asthma and OSA in children are limited but indicate that there is a bi-directional relationship between them with significant overlap in the symptoms, risk factors, pathophysiology, comorbidities, and management. It is suggested that there is a reciprocal association between asthma predisposing to OSA, and OSA worsening symptom control and outcomes from asthma. It stands to reason that inflammation in the upper and/or lower airways can influence each other. Most of the pediatric literature that is available evaluates each aspect of this relationship independently such as risk factors, mechanisms, and treatment indications. This article highlights the relationship between OSA and asthma in the context of shared risk factors, pathophysiology, and available management recommendations in the pediatric population. Early recognition of the co-existence and association between OSA and asthma could ideally improve the treatment outcomes for these two conditions. Gaining a better understanding of the mechanism of this relationship can help identify nuances for medical management, optimize treatment and protect this population at risk from associated morbidity.

Asthma and obstructive sleep apnoea in adults and children - an up-to-date review

Obstructive sleep apnoea (OSA) and asthma are two common respiratory disorders in children and adults. Apart from common risk factors, such as obesity, gastroesophageal reflux disease and allergic rhinitis, emerging evidence suggest that the two diseases may complicate the clinical course of each other. On one hand, OSA modifies asthmatic airway inflammation and is associated with poor asthma control. On the other hand, asthma and its medications increase the collapsibility of the upper airways contributing to the development and worsening of OSA. The overnight respiratory symptoms of OSA and asthma are often similar, and an inpatient polysomnography is often necessary for a proper diagnosis, especially in children. Continuous positive pressure, the gold standard treatment for OSA can improve asthma control in patients suffering from both diseases. However, there is limited evidence how anti-asthma medications act in the same patients. Nevertheless, adenotonsillectomy seems to be effective in children with concomitant asthma and OSA. This review summarises the evidence for the bidirectional link between asthma and OSA, focuses on diagnostic and therapeutic challenges and highlights the need for further research.

Characteristics of airway resistance in obstructive sleep apnea patients with asthma on oscillometry

BACKGROUND

Asthma and obstructive sleep apnea (OSA) are prevalent chronic respiratory disorders with a high tendency to coexist. Both diseases involve increased airway resistance in the upright position because of narrow upper or lower airways. Moreover, there is a marked increase in airway resistance in the supine position in patients with OSA. We verified the characteristics of OSA in combination with asthma.

METHODS

Airway resistance was measured by oscillometry in the upright and supine position in 11 healthy participants (control), 59 patients with OSA alone, and 33 OSA patients with asthma (coexistence) in the hospital between April 2014 and July 2020. We compared the differences in airway resistance between the upright and supine positions among the three groups. In addition, we performed cephalometry to evaluate the upper airway structure in patients with OSA alone and in patients with both OSA and asthma.

RESULTS

A marked increase in airway resistance due to postural change was observed in the "OSA alone" group compared to that in the control group. However, this was not observed in the "coexistence" and control groups. Moreover, the "coexistence" group had fewer structural abnormalities in the upper airway than the "OSA alone" group on cephalometry.

CONCLUSIONS

The airway resistance of patients with OSA alone markedly increased with posture change because of upper airway abnormalities. However, there was a smaller increase with postural changes in OSA patients with asthma, suggesting the possibility of a smaller degree of upper airway abnormality compared to patients with OSA alone.

CLINICAL TRIAL REGISTRATION NUMBER

This study is approved by the research ethics committee of the Shinshu University School of Medicine (permission number: 4272).

The negative health effects of having a combination of snoring and insomnia

STUDY OBJECTIVES

Insomnia and snoring are common sleep disorders. The aim was to investigate the association of having a combination of insomnia symptoms and snoring with comorbidity and daytime sleepiness.

METHODS

The study population comprised 25,901 participants (16-75 years, 54.4% women) from four Swedish cities, who answered a postal questionnaire that contained questions on snoring, insomnia symptoms (difficulties initiating and/or maintaining sleep and/or early morning awakening), smoking, educational level, and respiratory and non-respiratory disorders.

RESULTS

Snoring was reported by 4,221 (16.2%), while 9,872 (38.1%) reported ≥ 1 insomnia symptom. A total of 2,150 (8.3%) participants reported both insomnia symptoms and snoring. The association with hypertension (adj. OR 1.4, 95% CI: 1.2-1.6), chronic obstructive pulmonary disease (COPD) (adj. OR 1.8, 95% CI: 1.3-2.4), asthma (adj. OR 1.9; 95% CI: 1.6-2.3), daytime sleepiness (adj. OR 7.9, 95% CI 7.1-8.8) and the use of hypnotics (adj. OR 7.5, 95% CI: 6.1-9.1) was highest for the group with both insomnia symptoms and snoring.

CONCLUSIONS

Participants with both snoring and insomnia run an increased risk of hypertension, COPD, asthma, daytime sleepiness and the use of hypnotics. It is important to consider snoring in patients seeking medical assistance for insomnia and, vice versa, in patients with snoring inquiring about insomnia.

Obstructive Sleep Apnea and Asthma: More Than Chance?

Purpose of Review

To discuss the current evidence regarding the association and mechanistic interaction between asthma and obstructive sleep apnea (OSA).

Recent Findings

The co-existence of OSA is highly prevalent in asthmatics and significantly associated with increased severity, decreased control, more frequent exacerbations, and hospitalizations despite medical management. Pre-existing asthma may also be a risk factor for new onset OSA. Rhinitis, obesity, and gastro-esophageal reflux are risk factors in both conditions. The obese asthmatic with OSA may present a unique phenotype. Positive airway pressure in severe asthma improves outcomes.

Summary

Pathophysiologic mechanisms and co-morbidities overlap between OSA and asthma, but the exact link has yet to be confirmed. Screening for OSA is recommended in those with severe asthma. Further investigations are needed to delineate the cellular processes with therapeutic targets. Similarly, prospective investigations are needed to evaluate the longitudinal relationship in pre-existing asthma and the development of OSA.

Comparing the effects of supplemental oxygen therapy and continuous positive airway pressure on patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) is associated with hypertension, psychological impairment, neurocognitive dysfunction, and poor quality of sleep. Continuous positive airway pressure (CPAP) has been confirmed to effectively improve OSA, while the effects of supplemental oxygen therapy on OSA have still remained controversial. This meta-analysis aimed to compare the effects of supplemental oxygen therapy and CPAP on patients with OSA.

METHODS

PubMed, Cochrane library, EMBASE, and Web of Science databases were systematically searched from inception until April 2020. Randomized controlled trials (RCTs) that compared the effects of supplemental oxygen therapy and CPAP on patients with OSA were selected without language restriction.

RESULTS

In this meta-analysis, 8 RCTs that involved 887 patients were found eligible for further analyses. Pooled data showed that there was no significant difference in improving nocturnal oxygen saturation (SpO₂) level (95% confidence interval (CI) = - 1.17 to 1.53) or symptoms of depression (95%CI = - 0.69 to 1.19) between supplemental oxygen therapy and CPAP. Supplemental oxygen therapy was found less effective in reducing apnea-hypopnea index (AHI), time of SpO₂ < 90%, blood pressure, and improving quality of sleep compared with CPAP. A subgroup analysis based on flow rate of oxygen indicated that the effects of supplemental oxygen therapy on blood pressure significantly differed. Furthermore, an improvement in overall time of SpO₂ < 90% was correlated to duration of supplemental oxygen therapy.

CONCLUSIONS

CPAP is clinically effective for the treatment of patients with OSA. However, supplemental oxygen therapy can be cautiously used for improving nocturnal hypoxia and symptoms of depression when CPAP is not acceptable or not tolerated. Supplemental oxygen therapy is a promising option to alleviate partial disorders of OSA. Further studies need to focus on flow rate of oxygen and duration of supplemental oxygen therapy.

Association between tumor necrosis factor alpha and obstructive sleep apnea in adults: a meta-analysis update

BACKGROUND

Tumor necrosis factor-α (TNF-α) has been reported to play a part in the development of obstructive sleep apnea (OSA) and its complications. However, the relationship between TNF-α and OSA still remains inconclusive. We aimed to systematically review and synthesize studies published to date on association between the two in adults.

METHODS

We searched for English-language articles containing original human data from case-control study studies in adults≥18 years of age. The selection criteria were set according to the PICOS framework. Articles were independently reviewed by three investigators. Data regarding demographics, clinical characteristics, and TNF-α levels were obtained. A random-effects model was applied to evaluate the overall effect sizes by calculating standard mean difference (SMD) and its 95% confidence intervals (CIs).

RESULTS

Of 393 identified abstracts, 50 articles (3503 OSA patients and 3379 health controls) were ultimately included in this meta-analysis. The results indicated that the TNF-α level in patients with OSA was 1.77 (95%CI, 1.37 to 2.17, I² = 97.8%, P < 0.0001) times higher than in the control group. Subgroup analyses showed a positive correlation between the level of TNF-α and OSA severity. According to meta-regression, we noted that aging significantly predicted an increased effect size of TNF-α level in OSA patients (P < 0.007).

CONCLUSION

This study identified a significant association between OSA and elevated TNF-α level in adults. Meanwhile, TNF-α levels were consistently correlated with severity of OSA, which indicated it might be a promising biomarker for the development of OSA. However, well-designed, large-scale, case-control cohorts are needed to better understand the relationship of TNF-α in the context of adult OSA.

Evaluation of Serum and Plasma Interleukin-6 Levels in Obstructive Sleep Apnea Syndrome: A Meta-Analysis and Meta-Regression

Obstructive sleep apnea syndrome (OSAS) is considered a low-grade chronic inflammatory disease. Interleukin-6 (IL-6) is one of the most significant inflammatory markers and an excellent proxy for the inflammatory/immune system. The present meta-analysis and meta-regression aimed at comparing plasma and serum levels of IL-6 between individuals (children and adults) with OSAS and healthy controls. Four databases, PubMed/Medline, Scopus, Cochrane Library, and Web of Science, were comprehensively searched to retrieve articles published up to December, 2019, with no further restrictions. RevMan 5.3 software was used to calculate the crude mean difference (MD) and 95% confidence interval (CI). The results of funnel plots and meta-regression were analyzed by the CMA 2.0 software. Sixty-three studies (57 with adults; six with children) were included in the present meta-analysis. For adults, 37 studies reported significantly higher serum IL-6 levels and 20 reported significantly higher plasma IL-6 levels for those with OSAS than for healthy controls [pooled MD of 2.89 pg/ml (P < 0.00001) and pooled MD of 2.89 pg/ml (P < 0.00001), respectively]. The pooled analysis of serum and plasma IL-6 levels in children with OSAS compared with controls revealed that only the MD of plasma IL-6 levels was significant (MD = 0.84 pg/ml, P = 0.004). Results of the meta-regression showed that greater age was associated with higher serum IL-6 levels. Egger's test revealed a publication bias across the studies for serum and plasma IL-6 levels (P = 0.00044 and P = 0.01445, respectively). In summary, the meta-analysis and meta-regression confirmed that, compared to healthy controls, individuals with OSAS (children and adults) had higher serum/plasma IL-6 levels.

Association between lung function decline and obstructive sleep apnoea: the ALEC study

Purpose

To study changes in lung function among individuals with a risk of obstructive sleep apnoea (OSA), and if asthma affected this relationship.

Methods

We used data from the European Community Respiratory Health Survey II and III, a multicentre general population study. Participants answered questionnaires and performed spirometry at baseline and 10-year follow-up (n = 4,329 attended both visits). Subjects with high risk for OSA were identified from the multivariable apnoea prediction (MAP) index, calculated from BMI, age, gender, and OSA symptoms at follow-up. Asthma was defined as having doctor’s diagnosed asthma at follow-up. Primary outcomes were changes in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) from baseline to follow-up.

Results

Among 5108 participants at follow-up, 991 (19%) had a high risk of OSA based on the MAP index. Participants with high OSA risk more often had wheeze, cough, chest tightness, and breathlessness at follow-up than those with low OSA risk. Lung function declined more rapidly in subjects with high OSA risk (low vs high OSA risk [mean ± SD]: FEV1 = − 41.3 ± 24.3 ml/year vs − 50.8 ± 30.1 ml/year; FVC = − 30.5 ± 31.2 ml/year vs − 45.2 ± 36.3 ml/year). Lung function decline was primarily associated with higher BMI and OSA symptoms. OSA symptoms had a stronger association with lung function decline among asthmatics, compared to non-asthmatics.

Conclusion

In the general population, a high probability of obstructive sleep apnoea was related to faster lung function decline in the previous decade. This was driven by a higher BMI and more OSA symptoms among these subjects. The association between OSA symptoms and lung function decline was stronger among asthmatics.

Electronic supplementary material

The online version of this article (10.1007/s11325-020-02086-1) contains supplementary material, which is available to authorized users.

Update in Pediatric Asthma: Selected Issues

Asthma is a complex condition that affects 14% of the world's children and the approach to management includes both pharmacologic as well as non-pharmacologic strategies including attention to complex socioeconomic status phenomena. After an historical consideration of asthma, allergic and immunologic aspects of asthma in children and adolescents are presented. Concepts of socioeconomic aspects of asthma are considered along with environmental features and complications of asthma disparities. Also reviewed are links of asthma with mental health disorders, sleep disturbances and other comorbidities. A stepwise approach to asthma management is discussed that includes pharmacologic and non-pharmacologic strategies in the pediatric population. The role of immunotherapy and use of various immunomodulators are considered as well.

Τhe Co-Existence of Obstructive Sleep Apnea and Bronchial Asthma: Revelation of a New Asthma Phenotype?

Bronchial asthma (BA) and obstructive sleep apnea (OSA) are common respiratory obstructive diseases that may coexist. It would be interesting to study the possible influence of that coexistence on both diseases. Until now, reviews focused mainly on epidemiology. The aim of this study was to review the literature in relation to epidemiology, pathophysiology, consequences, screening of patients, and treatment of the coexistence of OSA and BA. We pooled studies from the PubMed database from 1986 to 2019. OSA prevalence in asthmatics was found to be high, ranging from19% to 60% in non-severe BA, reaching up to 95% in severe asthma. Prevalence was correlated with the duration and severity of BA, and increased dosage of steroids taken orally or by inhalation. This high prevalence of the coexistence of OSA and BA diseases could not be a result of just chance. It seems that this coexistence is based on the pathophysiology of the diseases. In most studies, OSA seems to deteriorate asthma outcomes, and mainly exacerbates them. CPAP (continuous positive airway pressure) treatment is likely to improve symptoms, the control of the disease, and the quality of life in asthmatics with OSA. However, almost all studies are observational, involving a small number of patients with a short period of follow up. Although treatment guidelines cannot be released, we could recommend periodic screening of asthmatics for OSA for the optimal treatment of both the diseases.

Complicating effects of obstructive sleep apnea syndrome on the severity of adult asthma

Introduction: Bronchial asthma (BA) and obstructive sleep apnea syndrome (OSAS) are common causes of respiratory disturbance. Many cases of patients with both conditions have been reported, and BA and OSAS may exacerbate each other, but information remains sparse.Methods:We retrospectively evaluated 60 patients under treatment for BA in our department between April 2016 and March 2018 who also underwent portable polysomnography (PSG) for suspected OSAS to assess potential association between PSG results and asthma treatment or respiratory function. BA was diagnosed and treated according to the Asthma Prevention and Management Guideline 2015.Results: We found that BA treatment intensity step was significantly higher for patients with BA who had concurrent moderate or severe OSAS (p = 0.0016). However, neither respiratory function, fraction of exhaled nitric oxide (FeNO), nor forced oscillation technique (FOT) differed significantly between patients with and without OSAS, and apnea hypopnea index was not significantly correlated with respiratory function, FeNO or FOT parameters.Conclusion:We conclude that even though BA patients with OSAS had good respiratory function, their BA was more severe than that of patients without OSAS, suggesting that OSAS may exacerbate BA. Background factors and asthma parameters were not predictive of PSG results, and patients with suspected OSAS should be evaluated proactively by using PSG.

Snoring and nocturnal reflux: association with lung function decline and respiratory symptoms

Introduction

The study aim was to examine the association of snoring and nocturnal gastro-oesophageal reflux (nGOR) with respiratory symptoms and lung function, and if snoring and/or nGOR associated with a steeper decline in lung function.

Methods

Data from the third visit of the European Community Respiratory Health Survey (ECRHS) was used for cross-sectional analysis. Pre- and post-bronchodilator spirometry was performed, and information on sleep, nGOR and respiratory symptoms was collected (n=5715). Habitual snoring and nGOR were assessed by questionnaire reports. Pre-bronchodilator spirometry from ECRHS I, II and III (20 years follow-up) were used to analyse lung function changes by multivariate regression analysis.

Results

Snoring and nGOR were independently associated with a higher prevalence of wheeze, chest tightness, breathlessness, cough and phlegm. The prevalence of any respiratory symptom was 79% in subjects with both snoring and nGOR versus 56% in those with neither (p<0.001). Subjects with both snoring and nGOR had more frequent exacerbations (adjusted prevalence 32% versus 19% among "no snoring, no nGOR", p=0.003). Snoring but not nGOR was associated with a steeper decline in forced expiratory volume in 1 s over 10 years after adjusting for confounding factors (change in % predicted -5.53, versus -4.58 among "no snoring", p=0.04) and forced vital capacity (change in % predicted -1.94, versus -0.99 among "no snoring", p=0.03).

Conclusions

Adults reporting both habitual snoring and nGOR had more respiratory symptoms and more frequent exacerbations of these symptoms. Habitual snoring was associated with a steeper decline in lung function over time.

Obstructive sleep apnea and comorbidities: a dangerous liaison

Obstructive sleep apnea (OSA) is a highly prevalent disease, and is traditionally associated with increased cardiovascular risk. The role of comorbidities in OSA patients has emerged recently, and new conditions significantly associated with OSA are increasingly reported. A high comorbidity burden worsens prognosis, but some data suggest that CPAP might be protective especially in patients with comorbidities. Aim of this narrative review is to provide an update on recent studies, with special attention to cardiovascular and cerebrovascular comorbidities, the metabolic syndrome and type 2 diabetes, asthma, COPD and cancer. Better phenotypic characterization of OSA patients, including comorbidities, will help to provide better individualized care. The unsatisfactory adherence to CPAP in patients without daytime sleepiness should prompt clinicians to examine the overall risk profile of each patient in order to identify subjects at high risk for worse prognosis and provide the optimal treatment not only for OSA, but also for comorbidities.

Current opinions for the management of asthma associated with ear, nose and throat comorbidities

Ear, nose and throat (ENT) comorbidities are common in patients with asthma and are frequently associated with poorer asthma outcomes. All these comorbidities are "treatable traits" in asthma. Identification and management of these disorders may spare medication usage and contribute to improved asthma control and quality of life, and a decrease in exacerbation rates.This review summarises recent data about the prevalence, clinical impact and treatment effects of ENT comorbidities in asthma including allergic rhinitis, chronic rhinosinusitis with and without nasal polyposis, aspirin-exacerbated respiratory disease, obstructive sleep apnoea and vocal cord dysfunction.Many of these comorbidities are possible to be managed by the pulmonologist, but the collaboration with the ENT specialist is essential for patients with chronic rhinosinusitis or vocal cord dysfunction. Further rigorous research is needed to study the efficacy of comorbidity treatment to improve asthma outcomes, in particular with the development of biotherapies in severe asthma that can also be beneficial in some ENT diseases.

Continuous positive airway pressure for obstructive sleep apnoea does not improve asthma control

BACKGROUND AND OBJECTIVE

Unrecognized obstructive sleep apnoea syndrome (OSAS) may lead to poor asthma control despite optimal therapy. We assessed asthma control, airway responsiveness, daytime sleepiness and health status at baseline and 3 months after continuous positive airway pressure (CPAP) treatment among asthma patients with nocturnal symptoms and OSAS.

METHODS

Patients with nocturnal asthma symptoms despite receiving at least moderate-dose inhaled corticosteroid and long-acting bronchodilators underwent a home sleep study using 'Embletta' portable diagnostic system. Patients with significant OSAS (apnoea-hypopnoea index (AHI) ≥10/h) were randomized to receive either CPAP or conservative treatment for 3 months.

RESULTS

Among 145 patients recruited, 122 underwent sleep study with 41 (33.6%) having AHI ≥10/h. Patients with significant OSAS had higher BMI (27.4 (5.1) vs 25.1 (4.5) kg/m² , P = 0.016), bigger neck circumference (36.6 (3.1) vs 34.8 (3.6) cm, P = 0.006) and lower minimum SaO₂ (80.7 (6.6) vs 87.2 (3.9) %, P < 0.001). Using intention-to-treat analysis among 37 patients with AHI ≥10/h (CPAP group (n = 17) vs control group (n = 20)), there was no significant difference in Asthma Control Test score (CPAP 3.2 (2.7) vs control 2.4 (5.7), P = 0.568) but the CPAP group had a greater improvement in Epworth Sleepiness Scale (-3.0 (4.5) vs 0.5(3.8), P = 0.014), Asthma Quality of Life Questionnaire (0.6 (0.8) vs 0.02 (0.7), P = 0.022) and vitality domain in the SF-36 questionnaire (14.7 (16.8) vs 0.3 (16.2), P = 0.012) after 3 months. Data are presented as mean (SD) unless otherwise stated.

CONCLUSION

A high prevalence of OSAS was found among patients with asthma and snoring. CPAP therapy for 3 months did not enhance asthma control but improved daytime sleepiness, quality of life and vitality.