Impact of obstructive sleep apnea on severe asthma exacerbations

Association of obstructive sleep apnea risk with allergic asthma: A systematic review and meta-analysis

BACKGROUND

There is a close relationship between asthma and obstructive sleep apnea (OSA), and the mechanisms of these 2 diseases are overlapped. However, the relationship between OSA and allergic asthma remains to be analyzed through systematic review and meta-analysis.

METHODS

A systematic search was conducted using Scopus, PubMed, ISI, Google Scholar, and Cochrane Library by utilizing the keywords Allergic asthma, Obstructive sleep apnea, and OSA. Hazard ratio, odds ratio (OR), and risk ratio with 95% confidence interval, fixed and Mantel-Haenszel methods were calculated. Statistical software Stata was used for the evaluation of this meta-analysis.

RESULTS

Finally, 19 articles were included in this study. The prevalence of OSA in allergic asthma patients was 35.25% (19.92%, 50.57%), which was statistically significant, and pooled analysis of ORs observed in individual studies showed that the odds of OSA prevalence were 2.24 (1.32, 3.12) (P < 0.001). Also, the prevalence of OSA risk in allergic asthma patients was 30.08% (19.73%, 40.43%), which was statistically significant, and pooled analysis of ORs observed in individual studies showed that the odds of OSA risk were 3.46 (2.96, 4.94) (P < 0.001).

CONCLUSION

The present meta-analysis showed that the prevalence of OSA as well as the OSA risk in patients with asthma were significantly higher compared with healthy people.

Sleep Deficiency, Sleep Apnea, and Chronic Lung Disease

With sleep occupying up to one-third of every adult's life, addressing sleep is essential to overall health. Sleep disturbance and deficiency are common in patients with chronic lung diseases and associated with worse clinical outcomes and poor quality of life. A detailed history incorporating nocturnal respiratory symptoms, symptoms of obstructive sleep apnea (OSA) and restless legs syndrome, symptoms of anxiety and depression, and medications is the first step in identifying and addressing the multiple factors often contributing to sleep deficiency in chronic lung disease. Additional research is needed to better understand the relationship between sleep deficiency and the spectrum of chronic lung diseases.

State of the art: Alternative overlap syndrome-asthma and obstructive sleep apnea

In the general population, Bronchial Asthma (BA) and Obstructive Sleep Apnea (OSA) are among the most prevalent chronic respiratory disorders. Significant epidemiologic connections and complex pathogenetic pathways link these disorders via complex interactions at genetic, epigenetic, and environmental levels. The coexistence of BA and OSA in an individual likely represents a distinct syndrome, that is, a collection of clinical manifestations attributable to several mechanisms and pathobiological signatures. To avoid terminological confusion, this association has been named alternative overlap syndrome (vs overlap syndrome represented by the chronic obstructive pulmonary disease-OSA association). This comprehensive review summarizes the complex, often bidirectional links between the constituents of the alternative overlap syndrome. Cross-sectional, population, or clinic-based studies are unlikely to elucidate causality or directionality in these relationships. Even longitudinal epidemiological evaluations in BA cohorts developing over time OSA, or OSA cohorts developing BA during follow-up cannot exclude time factors or causal influence of other known or unknown mediators. As such, a lot of pathophysiological interactions described here have suggestive evidence, biological plausibility, potential or actual directionality. By showcasing existing evidence and current knowledge gaps, the hope is that deliberate, focused, and collaborative efforts in the near-future will be geared toward opportunities to shine light on the unknowns and accelerate discovery in this field of health, clinical care, education, research, and scholarly endeavors.

Mutual Influence Between Allergic Rhinitis and Sleep: Factors, Mechanisms, and interventions-A Narrative Review

Patients with allergic rhinitis (AR) have a high incidence of sleep disorders, such as insomnia, which can easily exacerbate nasal symptoms. The aggravation of nasal symptoms further promotes the deterioration of sleep disorders, forming a vicious cycle. Severe cases may even trigger psychological and neurological issues, such as anxiety, depression, and cognitive impairment, causing significant distress to patients, making clinical diagnosis and treatment difficult, and increasing costs. Furthermore, satisfactory therapeutics remain lacking. As the pathogenesis of AR-associated sleep disorders is not clear and research is still insufficient, paying attention to and understanding AR-related sleep disorders is crucial in clinical practice. Multiple studies have shown that the most crucial issues in current research on AR and sleep are analyzing the relationship between AR and sleep disorders, searching for the influencing factors, and investigating potential targets for diagnosis and treatment. This review aimed to identify and summarize the results of relevant studies using "AR" and "sleep disorders" as search terms. In addition, we evaluated the correlation between AR and sleep disorders and examined their interaction and potential mechanisms, offering a foundation for additional screening of potential diagnostic biomarkers and therapeutic targets.

Obstructive Sleep Apnea Is Associated with Worsened Hospital Outcomes in Children Hospitalized with Asthma

BACKGROUND

Studies have shown a bidirectional relationship between asthma and obstructive sleep apnea (OSA). However, there is a paucity of national-level data evaluating the impact of OSA on hospital outcomes in pediatric hospitalizations for asthma.

METHODS

We analyzed the National Inpatient Sample and Kids Inpatient Database to include all pediatric hospitalizations with a primary diagnosis of asthma between 2003-2016. Using ICD codes, the pediatric asthma cohort was divided into two groups: those with and those without a concomitant diagnosis of OSA. The primary outcomes were in-hospital mortality and the need for mechanical ventilation. The secondary outcomes were the lengths of each hospital stay and total hospitalization charges.

RESULTS

We analyzed 1,606,248 hospitalizations during the 14-year study period. The overall prevalence rate of OSA was 0.7%. Patients with asthma and OSA were significantly older (8.2 versus 5.9 years) and were more often male, p < 0.001. The OSA group had several increased comorbidities. The overall mortality rate was 0.03%, and multivariate regression analysis showed that OSA was associated with 4.3 times higher odds of in-hospital mortality (95% CI: 2.4 to 7.6, p < 0.001). Furthermore, OSA was associated with a 5.2 times greater need for mechanical ventilation (95% CI: 4.8 to 5.5, p < 0.001). Linear regression analyses demonstrated that OSA independently contributed an additional 0.82 days to the hospital stay length (95% CI: 0.79 to 0.86, p < 0.001) and an extra 10,479 USD (95% CI: 10,110 to 10,848, p < 0.001) in hospitalization charges.

CONCLUSION

OSA in children admitted with asthma is associated with poor hospital outcomes such as increased mortality risk, the need for mechanical ventilation, and increased healthcare utilization.

Association of Obesity and Severe Asthma in Adults

The incidence of obesity and asthma continues to enhance, significantly impacting global public health. Adipose tissue is an organ that secretes hormones and cytokines, causes meta-inflammation, and contributes to the intensification of bronchial hyperreactivity, oxidative stress, and consequently affects the different phenotypes of asthma in obese people. As body weight increases, the risk of severe asthma increases, as well as more frequent exacerbations requiring the use of glucocorticoids and hospitalization, which consequently leads to a deterioration of the quality of life. This review discusses the relationship between obesity and severe asthma, the underlying molecular mechanisms, changes in respiratory function tests in obese people, its impact on the occurrence of comorbidities, and consequently, a different response to conventional asthma treatment. The article also reviews research on possible future therapies for severe asthma. The manuscript is a narrative review of clinical trials in severe asthma and comorbid obesity. The articles were found in the PubMed database using the keywords asthma and obesity. Studies on severe asthma were then selected for inclusion in the article. The sections: 'The classification connected with asthma and obesity', 'Obesity-related changes in pulmonary functional tests', and 'Obesity and inflammation', include studies on subjects without asthma or non-severe asthma, which, according to the authors, familiarize the reader with the pathophysiology of obesity-related asthma.

Obstructive Sleep Apnea Effects on Chronic Airway Disease Exacerbations-Missed Opportunities for Improving Outcomes in Chronic Obstructive Pulmonary Disease and Asthma

In patients with chronic obstructive pulmonary disease (COPD) and asthma, exacerbations determine the natural history of both diseases. Patients with both respiratory diseases who suffer from obstructive sleep apnea (OSA) as a comorbidity (overlap syndromes) have a higher risk of exacerbations and hospitalization. In cases of OSA/COPD and OSA/asthma, continuous positive airway pressure treatment is indicated. Adequate adherence to therapy appears to reduce exacerbations and their severity, especially in OSA/COPD overlap. However, there is a lack of randomized trials that definitively demonstrate this evidence.

Contribution of Obstructive Sleep Apnea to Asthmatic Airway Inflammation and Impact of Its Treatment on the Course of Asthma

Asthma and obstructive sleep apnea (OSA) are very common respiratory disorders in the general population. Beyond their high prevalence, shared risk factors, and genetic linkages, bidirectional relationships between asthma and OSA exist, each disorder affecting the other's presence and severity. The author reviews here some of the salient links between constituents of the alternative overlap syndrome, that is, OSA comorbid with asthma, with an emphasis on the effects of OSA or its treatment on inflammation in asthma. In the directional relationship from OSA toward asthma, beyond direct influences, multiple factors and comorbidities seem to contribute.

Comorbidity of patients with noncommunicable diseases in general practice. Eurasian guidelines

Создание руководства поддержано Советом по терапевтическим наукам отделения клинической медицины Российской академии наук.

The prevalence of obstructive sleep apnea in Japanese asthma patients

BACKGROUND

Obstructive sleep apnea (OSA) occurs more commonly in asthma patients than in the general population because these conditions share some comorbidities. In Japan, the prevalence of OSA in the general population is reported to be approximately 20%; however, few reports have described the prevalence of OSA in asthma patients. Furthermore, the characteristics of Japanese patients with OSA and asthma are not clear.

METHODS

Adult asthma patients were recruited from the outpatient departments of our institution between August 31, 2017, and March 31, 2019. In all included patients, the presence and severity of OSA were evaluated by the Epworth Sleepiness Scale (ESS) and a home sleep test (HST) using portable polysomnography (PSG). The rate of coexisting OSA in asthma patients and the characteristics of those patients according to the severity of OSA were investigated.

RESULTS

Fifty-three patients were included. OSA was detected in 36 (67.9%) patients (mild, n = 15; moderate, n = 14; and severe, n = 7). Patients with OSA had significantly higher body mass index, Brinkman index, apnea-hypopnea index (AHI), and 3% oxygen desaturation index (ODI) values in comparison to those without OSA, while the percentage of the predicted value of forced vital capacity (%FVC) and lowest SpO2 levels were significantly lower. As the severity of OSA increased, age, brain natriuretic peptide level, AHI, and 3%ODI increased, and in contrast, FVC, %FVC, forced expiratory volume in one second (FEV1), percentage of the predicted value of FEV1 (%FEV1), Epworth Sleepiness Scale (ESS), 3%ODI, and lowest SpO2 levels decreased. In particular, the fact that the ESS value was inversely correlated with the severity of OSA in our patients was different from the general characteristics of OSA. Moreover, the AHI value was negatively correlated with FVC, %FVC, FEV1, and %FEV1. BMI was the only independent factor for the presence of OSA, and for asthma severity (FEV1, % of predicted), there was a weak correlation with smoking history.

CONCLUSIONS

This is the first report to investigate the prevalence of OSA in Japanese asthma patients, using an HST. This study suggests that an HST should be performed in addition to the sleep interview for asthma patients with refractory disease, a low pulmonary function, advanced age, and high BMI because the more severe the OSA, the lower the ESS value may be.

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.

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.

Brain response in asthma: the role of "lung-brain" axis mediated by neuroimmune crosstalk

In addition to typical respiratory symptoms, patients with asthma are frequently accompanied by cognitive decline, mood disorders (anxiety and depression), sleep disorders, olfactory disorders, and other brain response manifestations, all of which worsen asthma symptoms, form a vicious cycle, and exacerbate the burden on families and society. Therefore, studying the mechanism of neurological symptoms in patients with asthma is necessary to identify the appropriate preventative and therapeutic measures. In order to provide a comprehensive reference for related research, we compiled the pertinent literature, systematically summarized the latest research progress of asthma and its brain response, and attempted to reveal the possible "lung-brain" crosstalk mechanism and treatment methods at the onset of asthma, which will promote more related research to provide asthmatic patients with neurological symptoms new hope.

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.

Obstructive sleep apnea: The key for a better asthma control?

INTRODUCTION

Obstructive sleep apnea (OSA) is an important risk factor for poor asthma control. The objective of this study is to analyze the symptomatic control in asthmatic patients with OSA after using continuous positive airway pressure (CPAP).

METHODS

Patients were collected in a monographic asthma consult and a polygraphy was performed due to clinical suspicion or poor disease control. Asthma associated pathologies, as well as clinical and patient-perceived asthma control parameters were evaluated before and after the initiation of CPAP.

RESULTS

A hundred patients were included, 59% were women and 41% men. From them, 54% had severe OSA, 33% moderate OSA and 13% mild OSA, and 10% could not tolerate CPAP. Eighty four percent had a moderate or severe degree of asthma with fractional exhaled nitric oxide (FENO) 32 ± 24.6 ppm and an asthma control test (ACT) before CPAP of 19 ± 4. Asthma control before CPAP was good in 41% of patients, partial in 29%, and bad in 30%. After three or more months of CPAP, clinical asthma control was good in 70% (p < 0.001), perceived control by ACT after CPAP was 21 ± 4 (p < 0.001). When asked for their opinion, 51.5% referred clinical improvement after CPAP, no change in 46.5%.

CONCLUSIONS

The use of CPAP in asthmatic patients with OSA improves both clinical and perceived asthma control in a statistically significant way. Most patients had good adaptation to CPAP (90%) and 51.5% had clinical improvement.

Optimal follow-up period after switching to another inhaled corticosteroid/long-acting β2 agonist in patients with asthma: A retrospective study using Japanese administrative claims data

Switching inhalation devices is a reasonable option if problems with control, adherence, or inhalation technique occur in patients with asthma treated with inhaled corticosteroid (ICS)/long-acting β2 agonist (LABA). However, evidence to determine the extent to which the carefully monitored period persists after switching is insufficient. In this study, we aimed to investigate the duration of the carefully monitored period after switching to another ICS/LABA. This retrospective study used claims data from Japanese health insurance associations from May 2014 to April 2019. A total of 1,951 patients who switched to another ICS/LABA during the study period were selected for analysis. The relative risk of the first exacerbation after switching was calculated for each four-week interval after the switch compared with that before the switch in a self-controlled case series design. We further assessed patient background associated with exacerbations during the follow-up period. In the primary analysis, the risk of asthma exacerbation compared to the control period was derived from a conditional logistic regression model, which showed a significant decrease immediately after the switch (1 to 4 weeks, Odds ratio [OR] 0.37, 95% confidence interval [CI] 0.26–0.54). Subsequently, the risk increased again and was not significantly different from the control period until week 32 (OR 0.55, 95% CI 0.29–1.04). In a sensitivity analysis among patients with a history of exacerbations, up to week 20 was the period of no continuous risk reduction (OR 0.84, 95% CI 0.41–1.70). In the secondary analysis, chronic rhinosinusitis, sleep disorders, and a history of asthma exacerbation were significantly associated with asthma exacerbation. The incidence of exacerbation remained high for approximately 4 to 7 months after patients with asthma switched to another ICS/LABA. Therefore, these patients should be carefully monitored for at least 4 to 7 months and should be re-assessed at an earlier point in time, if necessary.

Differences in L-arginine metabolism and asthma morbidity among asthma patients with and without obstructive sleep apnea

BACKGROUND

Imbalance in L-arginine and nitric oxide (NO) metabolism has been implicated in the pathophysiology of asthma and obstructive sleep apnea (OSA), and both diseases impact the other's morbidity. We sought to determine whether L-arginine/NO metabolism differs between adults with asthma with or without comorbid OSA, and its association with asthma morbidity.

METHODS

This is a cross-sectional study of 322 adults with asthma recruited in Denver, CO and New York City, NY. Data were collected on OSA status, spirometry, and metrics of asthma control and morbidity. L-Arginine metabolites were quantified in patient serum. Bivariate analyses and multiple regression were performed to determine differences between L-arginine metabolism, OSA and association with asthma morbidity.

RESULTS

Among the 322 participants, 92 (28.5%) had OSA. The cohort was 81.6% female, 23.4% identified as Black and 30.6% as Latino. Patients with asthma and OSA had significantly higher serum concentrations of NO synthase inhibitor asymmetric dimethylarginine (ADMA) (p-value = 0.019), lower L-arginine to ornithine ratios (p-value = 0.003), and increased ornithine (p-value = 0.001) and proline levels (p-value < 0.001) compared to those without OSA. In adjusted models, OSA was associated with worse asthma control, adjusted mean difference in asthma control questionnaire of 0.36 (95% confidence interval [CI]: 0.06 to 0.65), and asthma quality of life questionnaire, adjusted mean difference: - 0.53 (95% CI: - 0.85 to - 0.21), after adjusting for relevant covariates including body mass index and L-arginine metabolites.

CONCLUSIONS

Adults with asthma and OSA had increased ADMA, an inhibitor of nitric oxide synthase, and greater metabolism of L-arginine via the arginase pathway compared to those with asthma alone, indicating a possible shared pathophysiological mechanism of these diseases.

The relationship between teen-reported nocturnal asthma symptoms and daily functioning

OBJECTIVE

This study aims to identify associations between nocturnal asthma awakenings and functional health outcomes in a cohort of teenagers with asthma.

METHODS

We analyzed baseline data from teenagers enrolled in SB-ACT, an NIH-funded RCT. During an at-home baseline survey, teenagers with asthma answered questions about demographics, recent asthma symptoms, and functional health outcomes. We conducted regression analyses to explore the relationship between persistent nocturnal asthma symptoms (≥2 nights of nocturnal asthma awakenings in the past 14 days) and functional health measures.

RESULTS

Of the 430 teens enrolled (Participation rate = 79%, Mean Age = 13.4), 30% reported persistent nocturnal asthma symptoms. Compared to teens with intermittent nocturnal asthma symptoms, teens with persistent nocturnal asthma symptoms were more likely to report physical limitation during strenuous activities (OR = 1.9, 1.3-3.0), moderate activities (OR = 1.9, 1.2-3.1), and school gym (OR = 2.4, 1.5-3.8). They were also more likely to report depressive symptoms (OR = 2.3, 1.5-3.6), more asthma-related school absenteeism in the past 14 days (0.81 vs 0.12, p < 0.01) and poorer quality of life (4.6 vs 5.9, p < 0.01). These findings remained significant when controlling for daytime asthma symptoms, weight status, race, ethnicity, gender, age, and smoke exposure.

CONCLUSIONS

In this cross-sectional study, persistent nighttime asthma symptoms were associated with poor functional health outcomes among teens, independent of day-time symptoms. Identifying nighttime symptoms and improving asthma control at night may positively impact daily functioning for these teens.

Sleep Deficiency, Sleep Apnea, and Chronic Lung Disease

With sleep occupying up to one-third of every adult's life, addressing sleep is essential to overall health. Sleep disturbance and deficiency are common in patients with chronic lung diseases and associated with worse clinical outcomes and poor quality of life. A detailed history incorporating nocturnal respiratory symptoms, symptoms of obstructive sleep apnea (OSA) and restless legs syndrome, symptoms of anxiety and depression, and medications is the first step in identifying and addressing the multiple factors often contributing to sleep deficiency in chronic lung disease. Additional research is needed to better understand the relationship between sleep deficiency and the spectrum of chronic lung diseases.

The Role of Comorbidities in Difficult-to-Control Asthma in Adults and Children

Assessment of asthma comorbidities, conditions that adversely affect the pathobiology of asthma or impair its response to therapies, is a fundamental step in the evaluation and management of patients with difficult-to-treat asthma. Identifying and effectively treating asthma comorbidities, such as obesity, obstructive sleep apnea, and chronic sinusitis with nasal polyps, may improve asthma control and reduce exacerbations. In addition, identifying comorbid T2 inflammatory conditions may help guide optimal selection of biologic therapies. Here, we describe common comorbid conditions found in adult and pediatric difficult-to-control asthma, discuss evidence for the association with asthma morbidity and treatment benefit, and provide information on how and when to assess comorbidities.

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.

Obstructive sleep apnea in patients with severe asthma: Prevalence and association between severity and asthma control

INTRODUCTION:

Asthma and obstructive sleep apnea (OSA) are common respiratory disorders that can coexist and cause sleep disturbances. The strength of this association and the impact of OSA on asthma severity and control remain unclear. The study aims to estimate the prevalence of OSA in patients with severe asthma in Oman and to examine whether the severity of OSA contributed to the level of asthma control.

METHODS:

Adult patients with confirmed diagnosis of severe asthma who attended the respiratory clinic in a tertiary hospital in Oman over a period of 19 months were enrolled in the study. Eligible participants were screened by asthma control test (ACT) and Berlin questionnaire (BQ). Patients with high risk for OSA were subjected further to level 3 sleep study. The prevalence of OSA in patients with severe asthma and the associations between the severity of OSA and asthma control were calculated.

RESULTS:

We identified 312 adult asthma patients on Global Initiative for Asthma step 4 or 5 management out of 550 who were screened. The mean age of the study population was 56.59 ± 12.40 years and the mean body mass index (BMI) 40.30 ± 12.24 kg/m². The prevalence of OSA in asthma patients with severe asthma was found to be 32.4%. Out of the 138 well-controlled asthma patients (ACT ≥20), 35 had high risk of OSA based on BQ, and 32 were confirmed to have OSA (23%). Of the 174 uncontrolled patients, 80 patients had high risk of OSA and 69 patients were confirmed to have OSA (39.65%). Severe OSA was seen in 63.8% and 9.4% in uncontrolled and controlled asthma patients, respectively (P = 0.002). The median respiratory event index in the uncontrolled group was 43, and it was significantly higher than 12.5 in the controlled group (P < 0.001).

CONCLUSIONS:

The prevalence of OSA was high (32.37%) in patients with severe asthma. Uncontrolled severe asthma was significantly associated with severe OSA.

2021 Brazilian Thoracic Association recommendations for the management of severe asthma

Advances in the understanding that severe asthma is a complex and heterogeneous disease and in the knowledge of the pathophysiology of asthma, with the identification of different phenotypes and endotypes, have allowed new approaches for the diagnosis and characterization of the disease and have resulted in relevant changes in pharmacological management. In this context, the definition of severe asthma has been established, being differentiated from difficult-to-control asthma. These recommendations address this topic and review advances in phenotyping, use of biomarkers, and new treatments for severe asthma. Emphasis is given to topics regarding personalized management of the patient and selection of biologicals, as well as the importance of evaluating the response to treatment. These recommendations apply to adults and children with severe asthma and are targeted at physicians involved in asthma treatment. A panel of 17 Brazilian pulmonologists was invited to review recent evidence on the diagnosis and management of severe asthma, adapting it to the Brazilian reality. Each of the experts was responsible for reviewing a topic or question relevant to the topic. In a second phase, four experts discussed and structured the texts produced, and, in the last phase, all experts reviewed and approved the present manuscript and its recommendations.

Obstructive Sleep Apnea in Patients with Head and Neck Cancer—More than Just a Comorbidity?

Obstructive sleep apnea is the most common type of sleep-disordered breathing with growing prevalence. Its presence has been associated with poor quality of life and serious comorbidities. There is increasing evidence for coexisting obstructive sleep apnea in patients suffering from head and neck cancer, a condition that ranks among the top ten most common types of cancer worldwide. Routinely, patients with head and neck cancer are treated with surgery, radiation therapy, chemotherapy, immunotherapy or a combination of these, all possibly interfering with the anatomy of the oral cavity, pharynx or larynx. Thus, cancer treatment might worsen already existing obstructive sleep apnea or trigger its occurrence. Hypoxia, the hallmark feature of obstructive sleep apnea, has an impact on cancer biology and its cure. Early diagnosis and sufficient treatment of coexisting obstructive sleep apnea in patients with head and neck cancer may improve quality of life and could also potentially improve oncological outcomes.

Asthma and Three Colinear Comorbidities: Obesity, OSA, and GERD

Asthma is a complex disease with heterogeneous phenotypes and endotypes that are incompletely understood. Obesity, obstructive sleep apnea, and gastroesophageal reflux disease co-occur in patients with asthma at higher rates than in those without asthma. Although these diseases share risk factors, there are some data suggesting that these comorbidities have shared inflammatory pathways, drive the development of asthma, or worsen asthma control. This review discusses the epidemiology, pathophysiology, management recommendations, and key knowledge gaps of these common comorbidities.

Interrelationship Between Obstructive Sleep Apnea Syndrome and Severe Asthma: From Endo-Phenotype to Clinical Aspects

Sleep-related breathing disorders (SBDs) are characterized by abnormal respiration during sleep. Obstructive sleep apnea (OSA), a common SBD increasingly recognized by physicians, is characterized by recurrent episodes of partial or complete closure of the upper airway resulting in disturbed breathing during sleep. OSA syndrome (OSAS) is associated with decreased patients' quality of life (QoL) and the presence of significant comorbidities, such as daytime sleepiness. Similarly to what seen for OSAS, the prevalence of asthma has been steadily rising in recent years. Interestingly, severe asthma (SA) patients are also affected by poor sleep quality—often attributed to nocturnal worsening of their asthma—and increased daytime sleepiness and snoring compared to the general population. The fact that such symptoms are also found in OSAS, and that these two conditions share common risk factors, such as obesity, rhinitis, and gastroesophageal reflux, has led many to postulate an association between these two conditions. Specifically, it has been proposed a bidirectional correlation between SA and OSAS, with a mutual negative effect in term of disease severity. According to this model, OSAS not only acts as an independent risk factor of asthma exacerbations, but its co-existence can also worsen asthma symptoms, and the same is true for asthma with respect to OSAS. In this comprehensive review, we summarize past and present studies on the interrelationship between OSAS and SA, from endo-phenotype to clinical aspects, highlighting possible implications for clinical practice and future research directions.

[Obstructive sleep apnea and asthma: Clinical implications]

Obstructive sleep apnea (OSA) and asthma are common respiratory diseases that can coexist in the same patient. Epidemiological and pathophysiological data suggest an independent link between these two diseases. Specially, OSA is frequently associated with non-eosinophilic and with poorly-controlled asthma. Common comorbidities including obesity, gastroesophageal reflux and rhinitis may promote this association. The impact of OSA treatment on the clinical and functional control of asthma has been extensively investigated. Numerous non-randomized studies suggest that continuous positive pressure treatment is likely to improve asthma symptoms, the control of the disease and quality of life in asthmatics with OSA. However, this impact has not been confirmed in the limited randomized trial available. To date, the optimal treatment approach in asthmatics with OSA is the best treatment of each disease separately and the recognition and treatment of comorbidities. When indicated, obesity surgery has a major impact on both diseases.

Association Between Sleep Characteristics and Asthma Control in Middle-Aged and Older Adults: A Prospective Cohort Study

Background

Nocturnal asthma symptoms are a well-known feature of sleep disturbance. However, there are few reports on the association between sleep-related characteristics and asthma exacerbation. The aim of the current prospective observational study was to explore the factors while sleeping associated with future asthma exacerbation.

Materials and Methods

At baseline, adult asthmatics underwent home sleep monitoring by a Watch-PAT instrument and then they were prospectively followed-up for the occurrence of exacerbations. The number of asthma exacerbation was observed over a period of one year, and multivariable analyses of the factors associated with asthma exacerbation were performed.

Results

A total of 62 asthmatic subjects were enrolled (mean age 62.1 years), 59 of whom were finally included in the prospective observational study. Obstructive sleep apnea (defined by an apnea-hypopnea index based on peripheral arterial tone more than 5 times/hour) were observed in 81% of the subjects. During the one-year monitoring period, 14 of the 59 subjects (24%) used occasional systemic corticosteroids for their exacerbation asthma (worsened group) while the other 45 subjects did not experience asthma exacerbation (stable group). A comparison of the baseline clinical characteristics and sleep-related data between the two groups, mean forced expiratory volume one second percent (FEV₁/FVC), mean baseline Asthma Control Test (ACT) score, median pAHI value, and median oxygen desaturation index value were significantly lower in the worsened group than those in the stable group. Additionally, mean prevalence of the left lateral decubitus (LLD) position in sleep monitoring were significantly higher in the worsened group than that in the stable group. Among the independent variables, baseline asthma severity, ACT score, and the LLD position showed significant associations with asthma exacerbation.

Discussion/Conclusion

The present study identified that sleeping in the LLD position was also associated with asthma exacerbation.

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.

Obstructive sleep apnea is a determinant of asthma control independent of smoking, reflux, and rhinitis

Background: Asthma control is defined as to what extent manifestations of asthma can be observed in a patient or have been reduced or removed by treatment. Regular use of asthma treatments, correct inhaler technique, adequate information provided about the patient's diseases and medicines, and patient-clinician collaboration aid asthma control. Asthma shares risk factors and links in the pathogenesis with obstructive sleep apnea (OSA), and OSA may aggravate asthma symptoms. Objective: To assess the risk of OSA for asthma control. Methods: The study was carried out in subjects with asthma who were followed up at specific time points and who used asthma medication regularly and with an appropriate inhaler technique. An asthma control test and a questionnaire were used to determine the asthma control levels and OSA risk of the subjects. Results: With regard to the questionnaire scoring, 77 of 137 subjects with asthma had a low OSA risk and 60 had a high OSA risk. The proportion of the subjects with a high OSA risk (p < 0.001) and were smokers (p = 0.020) were significantly higher in the subjects with uncontrolled asthma than in those with controlled asthma. Logistic regression analysis showed that the variables that affect asthma control status were the risk of OSA and obesity. The subjects with a low OSA risk were more likely to have controlled asthma than those with a high OSA risk (odds ratio 7.896 [95% confidence interval, 2.902-21.487]; p < 0.001). Conclusion: In the subjects with asthma and who adhered to therapy and used inhalers with the correct technique, a high risk of OSA was associated with poor control of their asthma. This association was independent of other factors, including rhinitis, gastroesophageal reflux, and smoking.

Asthma and Obstructive Sleep Apnea Overlap: What Has the Evidence Taught Us?

Obstructive sleep apnea (OSA) and asthma are highly prevalent chronic respiratory disorders. Beyond their frequent coexistence arising from their high prevalence and shared risk factors, these disorders feature a reciprocal interaction whereby each disease impacts the severity of the other. Emerging evidence implicates airway and systemic inflammation, neuroimmune interactions, and effects of asthma-controlling medications (corticosteroids) as factors that predispose patients with asthma to OSA. Conversely, undiagnosed or inadequately treated OSA adversely affects asthma control, partly via effects of intermittent hypoxia on airway inflammation and tissue remodeling. In this article, we review multiple lines of recently published evidence supporting this interaction. We provide a set of recommendations for clinicians involved in the care of adults with asthma, and identify critical gaps in our knowledge about this overlap.

Clinical features and risk factors in patients with asthma complicated with obstructive sleep apnea-hypopnea syndrome: a hospital-based study

PURPOSE

The current study was conducted to explore the clinical features and risk factors of patients with asthma complicated by obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

Patients with asthma who underwent polysomnography in our hospital from August 2017 to December 2019 were enrolled in the study. Data on demographics, pulmonary function testing, polysomnography, blood gases, mean pulmonary artery pressure, and vascular endothelial growth factor (VEGF) were compared between the two groups.

RESULTS

Of 238 patients with asthma, 93 who also had OSAHS formed the observation group and were subclassified into mild (n = 33), moderate (n = 41), and severe (n = 19) categories, while 145 patients with asthma alone were assigned to the control group. No significant differences were found in sex, age, course of disease, or pulmonary function between the two groups (P > 0.05), while the observation group showed more frequent allergic rhinitis and had greater BMI, neck circumference, mean pulmonary artery pressure (mPAP), and VEGF than those in the control group (P < 0.001). The peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and FEV₁/FVC in the mild group and the moderate group were higher than those in the severe group (P < 0.001). The durations of AHI and SaO₂ < 90% in the mild group and the moderate group were shorter than that in the severe group, and the lowest level of SaO₂ in the mild group and the moderate group was higher than that in the severe group (P <  0.05). The mPAP and VEGF of the mild and moderate groups were lower than those of severe group (P < 0.001), with mild group lower than moderate group (P < 0.001).

CONCLUSION

Significant differences in allergic rhinitis, BMI, neck circumference, AHI, SaO2, mPAP, and VEGF were observed in patients with asthma complicated by OSAHS. These parameters are risk factors associated with asthma complicated by OSAHS.

Association of obstructive sleep apnea with severity of patients hospitalized for acute asthma

BACKGROUND

Studies suggest that obstructive sleep apnea (OSA) is associated with suboptimal disease control and worse chronic severity of asthma. However, little is known about the relations of OSA with acute asthma severity in hospitalized patients.

OBJECTIVE

To investigate the association of OSA with acute asthma severity.

METHODS

This is a retrospective cohort study (2010-2013) using State Inpatient Databases from 8 geographically diverse states in the United States. The outcomes were markers of acute severity, including mechanical ventilation use, hospital length of stay, and in-hospital mortality. To determine the association of interest, we fit multivariable logistic regression models, adjusting for age, sex, race/ethnicity, primary insurance, household income, patient residence, comorbidities, hospital state, and hospitalization year. We repeated the analysis for children aged 6 to 17 years.

RESULTS

Among 73,408 adult patients hospitalized for acute asthma, 10.3% had OSA. Coexistent OSA was associated with a significantly higher risk of noninvasive positive pressure ventilation use (14.9% vs 3.1%; unadjusted odds ratio, 6.48; 95% CI, 5.88-7.13; adjusted odds ratio, 5.20; 95% CI, 4.65-5.80), whereas coexistent OSA was not significantly associated with the risk of invasive mechanical ventilation use. Patients with OSA had 37% longer hospital length of stay (unadjusted incidence rate ratio, 1.37; 95% CI, 1.33-1.40); this significant association persisted in the multivariable model (incidence rate ratio, 1.13; 95% CI, 1.10-1.17). The in-hospital mortality did not significantly differ between groups. These findings were consistent in both obesity and nonobesity groups and in 27,935 children.

CONCLUSION

Among patients hospitalized for acute asthma, OSA was associated with a higher risk of noninvasive positive pressure ventilation use and longer length of stay compared with those without OSA.

Comorbidities associated with severe asthma

Background:

Severe asthma can be a challenging disease to manage by the provider and by the patient, supported by evidence of increased health-care utilization by this population. Patients with severe asthma should be screened for comorbidities because these often contribute to poorly controlled asthma. The impact of comorbidities, however, are not completely understood.

Objective:

To review common comorbidities and their impact on severe asthma.

Methods:

A review of relevant clinical research studies that examined comorbidities in severe or difficult-to-treat asthma.

Results:

A number of comorbid diseases, including rhinitis, rhinosinusitis, gastroesophageal reflux, and obstructive sleep apnea, are associated with severe or difficult-to-treat asthma. If present and untreated, these conditions may adversely affect asthma control, quality of life, and/or lung function, despite adequate treatment with step-up asthma controller therapy.

Conclusion:

Treatable comorbidities are associated with severe and difficult-to-control asthma. Failure to recognize these comorbidities may divert appropriate care and increase disease burden. Assessment and management of these risk factors may contribute to improved asthma outcome; however, more investigation is needed to understand the relationship of comorbidities and asthma due to inconsistency in the findings.

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.

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.

IL-33 Mediated Inflammation in Chronic Respiratory Diseases-Understanding the Role of the Member of IL-1 Superfamily

Interleukin 33 (IL-33) is an alarmin cytokine from the IL-1 family. IL-33 is localized in the nucleus and acts there as a gene regulator. Following injury, stress or cell death, it is released from the nucleus, and exerts its pro-inflammatory biological functions via the transmembrane form of the ST2 receptor, which is present mainly as attached to immune cells. In recent years, IL-33 became a focus of many studies due to its possible role in inflammatory disorders. Among respiratory disorders, the contribution of IL-33 to the development of asthma, in particular, has been most identified. Increased level of IL-33 in lung epithelial cells and blood serum has been observed in asthma patients. The IL-33/ST2 interaction activated the Th2 mediated immune response and further production of many pro-inflammatory cytokines. Single nucleotide polymorphisms in the IL-33 gene cause a predisposition to the development of asthma. Similarly, in chronic pulmonary obstructive disease (COPD), both increased expression of IL-33 and the ST2 receptor has been observed. Interestingly, cigarette smoke, a key inducer of COPD, not only activates IL-33 production by epithelial and endothelial cells, but also induces the expression of IL-33 in peripheral blood mononuclear cells. Knowledge regarding its contribution in other respiratory disorders, such as obstructive sleep apnea, remains greatly limited. Recently it was shown that IL-33 is one of the inflammatory mediators by which levels in blood serum are increased in OSA patients, compared to healthy control patients. This mini review summarizes current knowledge on IL-33 involvement in chosen chronic respiratory disorders and proposes this interleukin as a possible link in the pathogenesis of these diseases.

Obesity and severe asthma

Obesity is an important global health issue for both children and adults. Obesity increases the prevalence and incidence of asthma and also increases the risk for severe asthma. Here we describe the features of severe asthma phenotypes for which obesity is a defining characteristic, including steroid resistance, airway inflammation, and co-morbidities. We also review current concepts regarding the mechanistic basis for the impact of obesity in severe asthma, including possible roles for vitamin D deficiency, systemic inflammation, and the microbiome. Finally, we describe data indicating a role for diet, weight loss, and exercise in the treatment of severe asthma with obesity. Better understanding of the mechanistic basis for the role of obesity in severe asthma could lead to new therapeutic options for this population.

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.

Nonallergic Triggers and Comorbidities in Asthma Exacerbations and Disease Severity

Asthma triggers are exogenous or endogenous factors that could worsen asthma acutely to cause an exacerbation, or perpetuate chronic symptoms and airflow limitation. Because it is well known that recent asthma exacerbations and poor symptom control are strong predictors of future disease activity, it is not surprising that the number of (allergic or nonallergic) asthma triggers in the environment correlates with the disease-related quality of life. There is a need to identify and avoid specific triggers as the centerpiece of disease management, especially in those with heightened sensitivity to certain factors.

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.

A proposed scheme to cope with comorbidities in asthma

The prevalence of non-communicable chronic diseases has been on the rise and the co-occurrence of morbidities is becoming more common. Multimorbidities are found more frequently among women, those with a history of mental disorders, lower level of schooling, and unfavorable socioeconomic condition. Physical inactivity, smoking and obesity are also associated with multimorbidities. Its occurrence is directly related to the age, affecting the majority of the individuals with more than 50 years old. It is important to consider the possibility of comorbid conditions that aggravate, complicate or simulate the symptoms of the disease in the face of a patient with asthma and poor response to treatment. Among subjects with asthma, some conditions stand out as the most frequent: chronic rhinitis or rhinosinusitis, gastroesophageal reflux disease, obstructive sleep apnea syndrome, obesity, and cardiovascular disorders. Comorbidities reduce the chances of optimal asthma control. It is essential to assess and manage properly these complex situations, choosing wisely preventive strategies and treatment options to avoid adverse events and optimize outcomes. Medications for asthma have the potential to worsen cardiovascular conditions, while beta-adrenergic receptor blockers and angiotensin conversion enzyme inhibitors used for cardiovascular conditions, can worsen asthma. Handling properly these cases will save lives and resources. However, there are multiple gaps in knowledge requiring investigation in this field to inform integrated care pathways and policies. It is likely information may be obtained from real life studies and electronic medical databases. Communications between the providers and patients may be facilitated by electronic technology, opening a large window for guided self-management.

Clinical presentation of patients with suspected obstructive sleep apnea and self-reported physician-diagnosed asthma in the ESADA cohort

Obstructive sleep apnea (OSA) and asthma are often associated and several studies suggest a bidirectional relationship between asthma and OSA. This study analyzed the characteristics of patients with suspected OSA from the European Sleep Apnea Database according to presence/absence of physician-diagnosed asthma. Cross-sectional data in 16,236 patients (29.1% female) referred for suspected OSA were analyzed according to occurrence of physician-diagnosed asthma for anthropometrics, OSA severity and sleepiness. Sleep structure was assessed in patients studied by polysomnography (i.e. 48% of the sample). The prevalence of physician-diagnosed asthma in the entire cohort was 4.8% (7.9% in women, 3.7% in men, p < 0.0001), and decreased from subjects without OSA to patients with mild-moderate and severe OSA (p = 0.02). Obesity was highly prevalent in asthmatic women, whereas BMI distribution was similar in men with and without physician-diagnosed asthma. Distribution of OSA severity was similar in patients with and without physician-diagnosed asthma, and unaffected by treatment for asthma or gastroesophageal reflux. Asthma was associated with poor sleep quality and sleepiness. Physician-diagnosed asthma was less common in a sleep clinic population than expected from the results of studies in the general population. Obesity appears as the major factor raising suspicion of OSA in asthmatic women, whereas complaints of poor sleep quality were the likely reason for referral in asthmatic men.

The association between asthma and obstructive sleep apnea (OSA): A systematic review

OBJECTIVE

Bronchial asthma and obstructive sleep apnoea (OSA) are common respiratory disorders that can co-exist. The strength of this association, and also the impact of OSA on asthma-related clinical outcomes remain unclear.

DATA SOURCES

Literature review was performed in EMBASE and MEDLINE databases. Studies up to and including 2016 were selected.

STUDY SELECTION

Studies were included if they contained; 1) a population with asthma AND 2) a prevalence of OSA reported using either polysomnography or validated questionnaires such as the Sleep Apnoea Scale of the Sleep Disorders Questionnaire (SA-SDQ), STOP BANG or the Berlin questionnaire.

RESULTS

Nineteen studies were identified. Thirteen questionnaire-based studies met the inclusion/exclusion criteria and twelve of these demonstrated a prevalence of OSA in asthma of 8-52.6%, with one study showing no association between the two conditions. Six studies using polysomnography demonstrated a high prevalence of 19.2-60%; which was higher at 50-95% in severe asthma. Two polysomnography and four questionnaire studies found worse asthma-related clinical outcomes with co-existing OSA. One polysomnography and two questionnaire studies showed no difference.

CONCLUSION

This systematic review suggests that there is a high prevalence of OSA in asthma, particularly within severe asthma populations and that co-diagnosis of OSA in asthma patients is associated with worse clinical outcomes. However this outcome was not uniform and the number of studies using polysomnography to confirm OSA was small. This weakens the conclusions that can be drawn and prompts the need for adequately powered and well-designed studies to confirm or refute these findings.

Screening for obstructive sleep apnea syndrome in asthma patients: a prospective study based on Berlin and STOP-Bang questionnaires

BACKGROUND

The bidirectional relationship of asthma and obstructive sleep apnea (OSA) has been confirmed in recent years. However, in the clinical practice, majority of asthma patients did not pay adequate attention to their sleep apnea condition. Berlin questionnaire (BQ) and STOP-Bang questionnaire (SBQ) are two most common OSA screening questionnaires to screen high-risk patients for OSA. This study aimed at evaluating the predictive performance of BQ and SBQ for OSA in asthma patients.

METHODS

Asthma outpatients of Zhongshan Hospital were enrolled into the study. All patients were asked to fill in the BQ and SBQ and clinical characteristics and asthma characteristics were recorded. Univariate and multivariate logistic regression analyses were applied to identify risk factors of OSA in asthma patients. With the gold standard of laboratory-based overnight polysomnography (PSG), the predictive performance of SBQ and BQ was evaluated and compared. The probability of OSA severity was predicted by various SBQ scores in asthma patients.

RESULTS

A total of 123 asthma patients (average age 47.56±12.12 years; 57.72% males) were enrolled and underwent PSG diagnosis overnight at Sleep Center. Logistic regression analyses showed that rhinitis (adjusted OR =4.30; 95% CI: 1.50-12.37, P=0.007) and dyslipidemia (adjusted OR =2.75; 95% CI: 1.16-6.51, P=0.021) were associated with OSA in asthma patients after adjusting for known OSA risk factors. No asthma functional characteristic differences were found to be associated with OSA severity in the study. The prevalence of moderate-to-severe OSA (AHI ≥15) in the asthmatic population sample was 36.59% (45/123). Questionnaires predictive results showed that compared with BQ, SBQ has higher diagnostic sensitivity (84.4% vs. 60%), lower specificity (79.5% vs. 91%) lower positive predictive value (PPV): (70.4% vs. 79.4%) and higher negative predictive value (NPV) (90% vs. 80%) to detect moderate-to-severe OSA at the cut-off as AHI of 15/h. OSA probability results showed that with the increasing of the questionnaire scores, the moderate and severe OSA probability of SBQ rose significantly.

CONCLUSIONS

SBQ is a preferable sleep questionnaire better than BQ for detecting moderate and severe OSA in asthma patients which should be validated in larger population sample.