Obstructive sleep apnea and influenza infection: a nationwide population-based cohort study

Obstructive Sleep Apnea and Risk of Respiratory Syncytial Viral Infection: A Retrospective Multi-Institution Cohort Study

This retrospective cohort study evaluated the association between obstructive sleep apnea (OSA) and the risk of respiratory syncytial virus (RSV) infection and its complications using data from the TriNetX US Collaborative Database. Patients diagnosed with OSA (n = 1 061 261) and matched controls (n = 3 479 494) were identified via ICD-10-CM codes. Propensity score matching adjusted for 19 covariates to balance baseline characteristics. Over a follow-up period ranging from 1 day to 1 year post-index, patients with OSA demonstrated a significantly higher incidence of RSV infection (0.18% vs. 0.08%; HR: 2.194, 95% CI: 2.025-2.378, p < 0.0001). Additionally, patients with OSA exhibited increased risks for severe RSV-related complications, including respiratory failure (HR: 1.291, 95% CI: 1.147-1.453), hospitalization (HR: 1.114, 95% CI: 1.026-1.210), and admission to critical care (HR: 1.329, 95% CI: 1.118-1.579). Sensitivity analyses confirmed the robustness of these findings across various observation periods, database subsets, study timelines, and inclusion criteria. Subgroup analyses stratified by age and gender also consistently supported the primary results. These findings suggest that OSA is associated with elevated risks of RSV infection and related severe outcomes, indicating the need for further studies to validate these results and potentially classify OSA patients as a high-risk group for RSV infection.

Sleep and Respiratory Infections

Sleep disorders that involve circadian rhythm disruption and sleep-disordered breathing (SDB) such as obstructive sleep apnea (OSA) are closely linked to respiratory infections. SDB leads to a proinflammatory state due to intermittent hypoxia, sleep fragmentation, increased oxidative stress, and elevation of inflammatory mediators such as tumor necrosis factor (TNF), interleukin-6 (IL-6), and C-reactive protein (CRP). Furthermore, inflammatory mediator levels correlate with SDB severity, especially in people with OSA. Nocturnal microaspiration, gastroesophageal reflux, and associated comorbidities (e.g., obesity) increase the risk of community-acquired pneumonia, viral infections such as SARS-CoV-2, respiratory complications, and death. OSA has been associated with post-COVID syndrome. It also increases the risk of postoperative complications in both adults and children. Circadian rhythm disorders such as insomnia predispose to immune disorders and increase the risk of infection. Chronic conditions such as bronchiectasis, with or without concomitant cystic fibrosis, can lead to structural sleep changes and increase the risk of OSA due to chronic cough, arousals, aspirations, hypoxia, upper airway edema, and overexpression of proinflammatory cytokines. The protective effect of treatment for sleep disorders against respiratory infection is currently unknown. However, in people presenting with respiratory infection, it is important to test for SDB to prevent complications.

Healthy sleep patterns and risk of hospitalization for infection: a large community-based cohort study

Sleep behaviours are potentially modifiable risk factors for infectious disease. However, little is known about the combined effects of multiple sleep factors on the risk of infections. We investigated the prospective associations of combined healthy sleep patterns with the risk of hospitalization for infection in 397,523 participants (mean (SD) age: 56.3 (8.1) years) from the UK Biobank. Healthy sleep patterns were defined by healthy sleep scores according to a combination of adequate sleep duration (7-8 h/day), early chronotype, no insomnia, and no excessive daytime sleepiness. During a median follow-up of 13.5 (interquartile range: 12.4-14.2) years, 60,377 cases of hospitalization for any infection were documented. A healthy sleep score was inversely associated with the risk of hospitalization for any infection and various infection subtypes in a dose-dependent manner (P for trend < 0.001). The associations between a one-point increment of healthy sleep score and hospitalization for infections ranged from a 9% lower risk for sepsis (HR = 0.91; 95% CI, 0.89-0.93) to a 20% lower risk for liver infection (HR = 0.80; 95% CI, 0.74-0.87). More than 10% of hospitalizations for any infection could have been prevented if all participants adhered to the four low-risk sleep behaviours. Adherence to a healthy sleep pattern was associated with a decreased risk of hospitalization for infections, especially for individuals <65 years of age and females (P for interaction < 0.00045). Our findings highlight the potential of sleep behaviour interventions for the primary prevention of infectious diseases.

UNVEILING THE CAUSAL ASSOCIATION BETWEEN NONINFECTIOUS RESPIRATORY DISORDERS AND SEPSIS THROUGH MENDELIAN RANDOMIZATION ANALYSIS

ABSTRACT

Background: The association between sepsis and noninfectious respiratory diseases is well-documented, yet the specific causal link between the two remains unclear. In order to explore this relationship further, we employed a Mendelian randomization (MR) analysis utilizing data from the UK Biobank and FinnGen Biobank. Methods: We analyzed the summary statistics of a genome-wide association study summary statistics for chronic obstructive pulmonary disease (COPD), asthma, pulmonary embolism (PE), idiopathic pulmonary fibrosis (IPF), obstructive sleep apnea (OSA), lung cancer, sepsis, and sepsis-related mortality. We employed the inverse-variance weighted (IVW) method and four additional MR methods. Heterogeneity and horizontal pleiotropy were assessed using the Cochrane's Q test, MR-Egger intercept, and MR-PRESSO test. A sensitivity analysis was also performed. Results: MR analysis showed associations between COPD and lung cancer with increased sepsis risk (odds ratio (OR)IVW 1.138, P = 0.006; (OR)IVW 1.123, P = 0.031; respectively) and sepsis mortality ((OR)IVW 1.350, P = 0.022; (OR)IVW 1.312, P = 0.022; respectively). Asthma exhibited a potential protective effect against sepsis mortality ((OR)IVW = 0.300, P = 0.039), while PE demonstrated a risk effect ((OR)IVW = 1.148, P = 0.032). No causal association was observed between asthma, PE, and sepsis ( P > 0.05). IPF and OSA were not significantly associated with sepsis or sepsis-related mortality ( P > 0.05). Heterogeneity and horizontal pleiotropy were not evident for asthma or lung cancer ( P > 0.05). However, horizontal pleiotropy was suggested for COPD by the MR-Egger regression ( P < 0.05), but not by the MR-PRESSO test ( P > 0.05). IPF and OSA were not significantly associated with sepsis or sepsis-related mortality ( P > 0.05). Conclusion: Our MR analysis offers new insights into potential links between noninfectious respiratory diseases and the risk of sepsis. However, additional investigation into the underlying mechanisms and clinical studies are necessary to confirm these findings.

Obstructive Sleep Apnea and Acute Lower Respiratory Tract Infections: A Narrative Literature Review

Both obstructive sleep apnea (OSA) and acute lower respiratory tract infections (LRTIs) are important global health issues. The pathophysiological links between OSA and LRTIs include altered immune responses due to chronic intermittent hypoxia and sleep fragmentation, increased aspiration risk, and a high burden of comorbidities. In this narrative review, we evaluated the current evidence on the association between OSA and the incidence and outcomes of acute LRTIs in adults, specifically community-acquired pneumonia and viral pneumonia caused by influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Studies have demonstrated that OSA patients are more likely to develop bacterial pneumonia and exhibit a higher risk of invasive pneumococcal disease. The risk intensifies with the severity of OSA, influencing hospitalization rates and the need for intensive care. OSA is also associated with an increased risk of contracting influenza and suffering more severe disease, potentially necessitating hospitalization. Similarly, OSA contributes to increased COVID-19 disease severity, reflected by higher rates of hospitalization, longer hospital stays, and a higher incidence of acute respiratory failure. The effect of OSA on mortality rates from these infections is, however, somewhat ambiguous. Finally, we explored antibiotic therapy for OSA patients with LRTIs, addressing care settings, empirical regimens, risks, and pharmacokinetic considerations. Given the substantial burden of OSA and its significant interplay with acute LRTIs, enhanced screening, targeted vaccinations, and optimized management strategies for OSA patients should be prioritized.

Impact of obstructive sleep apnea on clinical outcomes of hospitalization due to influenza in children: A propensity score-matched analysis of the US Nationwide Inpatient Sample 2005-2018

BACKGROUND

Previous studies have explored the association between obstructive sleep apnea (OSA) and clinical outcomes of influenza in adults, whereas limited research examined this relationship in pediatric populations. This study aimed to evaluate the clinical impact of OSA on the outcomes of pediatric influenza hospitalizations.

METHODS

This was a population-based, retrospective study. Data of children aged 1-19 years hospitalized for influenza infection were extracted from the United States (US) Nationwide Inpatient Sample Database 2005-2018. Univariable and multivariable regression analyses determined associations between OSA, length of stay (LOS), total hospital costs, pneumonia, and life-threatening events.

RESULTS

After propensity-score matching, a total of 2100 children were analyzed. The logistic analysis revealed that children with OSA had a significantly increased LOS (β = 2.29 days; 95% confidence interval, CI: 1.01-3.57, p < .001) and total hospital costs (β = 26.06 thousand dollars; 95% CI: 6.62-45.51, p = .009), and higher odds of pneumonia (aged 6-10 years: odds ratio [OR] = 1.52; 95% CI: 1.01-2.27, p = .043; aged ≥ 11 years: OR = 1.83; 95% CI: 1.33-2.53, p < .001).

CONCLUSIONS

During influenza admissions, children with OSA had longer LOS, higher hospital costs, and an increased risk of pneumonia compared to those without OSA. These findings underscore the importance of recognizing and managing OSA in influenza-related infections among children.

Effects of Obstructive Sleep Apnea on Airway Immunity and Susceptibility to Respiratory Infections

Obstructive sleep apnea is a prevalent sleep disorder characterized by recurrent episodes of partial or complete upper airway collapse during sleep, leading to disrupted breathing patterns and intermittent hypoxia. OSA results in systemic inflammation but also directly affects the upper and lower airways leading to upregulation of inflammatory pathways and alterations of the local microbiome. These changes result in increased susceptibility to respiratory infections such as influenza, COVID-19, and bacterial pneumonia. This relationship is more complex and bidirectional in individuals with chronic lung disease such as chronic obstructive lung disease, interstitial lung disease and bronchiectasis.

Excessive daytime sleepiness is associated with impaired antibody response to influenza vaccination in older male adults

Background

The reduced effectiveness of standard-dose influenza vaccines in persons ≥65 years of age led to the preferential recommendation to use high-dose (HDFlu) or MF59-adjuvanted (MF59Flu) vaccines for this age group. Sleep is an important modulator of immune responses to vaccines and poor sleep health is common in older adults. However, potential effects of poor sleep health on immune responses to influenza vaccination in older adults remain largely unknown.

Methods

We conducted a cohort study of 210 healthy participants age ≥65 years, who received either seasonal high-dose (HDFlu) or MF59-adjuvanted (MF59Flu) influenza vaccine. We assessed sleep characteristics in this cohort by standardized questionnaires and measured the antibody titer against influenza A/H3N2 virus in serum of study participants by hemagglutination inhibition assay on the day of immunization and 28 days thereafter. We then assessed the association between sleep characteristics and antibody titers.

Results

Our results demonstrated that male, but not female, study participants with excessive daytime sleepiness had an impaired influenza A/H3N2-specific antibody response at Day 28 post-vaccination. No other associations were found between antibody titer and other sleep characteristics, including sleep quality and obstructive sleep apnea.

Conclusion

Our results provide an additional and easily measured variable explaining poor vaccine effectiveness in older adults. Our results support that gaining sufficient sleep is a simple non-vaccine interventional approach to improve influenza immune responses in older adults. Our findings extend the literature on the negative influence of excessive daytime sleepiness on immune responses to influenza vaccination in older male adults.

Lower respiratory tract infections among newly diagnosed sleep apnea patients

BACKGROUND

Sleep apnea is associated with chronic comorbidities and acute complications. Existing data suggest that sleep apnea may predispose to an increased risk and severity of respiratory tract infections.

METHODS

We investigated the incidence of lower respiratory tract infections in the first and second year before and after diagnosis of sleep apnea in a Finnish nationwide, population-based, retrospective case-control study based on linking data from the national health care registers for primary and secondary care from 2015-2019. Controls were matched for age, sex, hospital district, and multimorbidity status. We furthermore analysed the independent effect of comorbidities and other patient characteristics on the risk of lower respiratory tract infections, and their recurrence.

RESULTS

Sleep apnea patients had a higher incidence of lower respiratory tract infections than their matched controls within one year before (hazard ratio 1.35, 95% confidence interval 1.16-1.57) and one year after (hazard ratio1.39, 95% confidence interval1.22-1.58) diagnosis of sleep apnea. However, we found no difference in the incidence of lower respiratory tract infections within the second year before or after diagnosis of sleep apnea in comparison with matched controls. In sleep apnea, history of lower respiratory tract infection prior to sleep apnea, multimorbidity, COPD, asthma, and age greater than 65 years increased the risk of incident and recurrent lower respiratory tract infections.

CONCLUSIONS

Sleep apnea patients are at increased risk of being diagnosed with a lower respiratory tract infection within but not beyond one year before and after diagnosis of sleep apnea. Among sleep apnea patients, chronic comorbidities had a significant impact on the risk of lower respiratory tract infections and their recurrence.

Development of a Deep Learning-Based Epiglottis Obstruction Ratio Calculation System

Surgeons determine the treatment method for patients with epiglottis obstruction based on its severity, often by estimating the obstruction severity (using three obstruction degrees) from the examination of drug-induced sleep endoscopy images. However, the use of obstruction degrees is inadequate and fails to correspond to changes in respiratory airflow. Current artificial intelligence image technologies can effectively address this issue. To enhance the accuracy of epiglottis obstruction assessment and replace obstruction degrees with obstruction ratios, this study developed a computer vision system with a deep learning-based method for calculating epiglottis obstruction ratios. The system employs a convolutional neural network, the YOLOv4 model, for epiglottis cartilage localization, a color quantization method to transform pixels into regions, and a region puzzle algorithm to calculate the range of a patient's epiglottis airway. This information is then utilized to compute the obstruction ratio of the patient's epiglottis site. Additionally, this system integrates web-based and PC-based programming technologies to realize its functionalities. Through experimental validation, this system was found to autonomously calculate obstruction ratios with a precision of 0.1% (ranging from 0% to 100%). It presents epiglottis obstruction levels as continuous data, providing crucial diagnostic insight for surgeons to assess the severity of epiglottis obstruction in patients.

Association of clinically significant obstructive sleep apnoea with risks of contracting COVID-19 and serious COVID-19 complications: a retrospective population-based study of health administrative data

RATIONALE/OBJECTIVES

Despite plausible pathophysiological mechanisms, more research is needed to confirm the relationship between obstructive sleep apnoea (OSA) and the risk of COVID-19 infection or COVID-19-related serious complications.

METHODS

We conducted a retrospective population-based cohort study using provincial health administrative data (Ontario, Canada). Adults with physician-diagnosed OSA who received positive airway pressure therapy in the 5 years prepandemic (OSA group) were propensity score matched by baseline characteristics to individuals in the general population at low risk of OSA (non-OSA group) using inverse probability of treatment weighting. Weighted HRs of (1) a positive COVID-19 test and (2) COVID-19-related emergency department (ED) visits, hospitalisations, intensive care unit (ICU) admissions and mortality, within 12 months of pandemic onset, were compared between groups. We also evaluated the impact of comorbid cardiometabolic or chronic airways disease.

RESULTS

We identified and matched 324 029 individuals in the OSA group to 4 588 200 individuals in the non-OSA group. Compared with the non-OSA group, those in the OSA group were at a greater hazard of testing positive for COVID-19 (HR=1.17, 95% CI 1.13 to 1.21), having a COVID-19-related ED visit (HR=1.62, 95% CI 1.51 to 1.73), hospitalisation (HR=1.50, 95% CI 1.37 to 1.65) or ICU admission (HR=1.53, 95% CI 1.27 to 1.84). COVID-19-related 30-day mortality was not different (HR=0.98, 95% CI 0.82 to 1.16).We found that for the OSA group, comorbid airways disease but not cardiometabolic conditions increased the hazards of COVID-19-related outcomes, including mortality.

CONCLUSION

In this large population-based study, we demonstrated that a recent diagnosis of OSA requiring treatment was associated with an increased hazard of testing positive for COVID-19 and serious COVID-19-related complications, particularly in those with co-existing chronic airways disease.

The public health impact of poor sleep on severe COVID-19, influenza and upper respiratory infections

BACKGROUND

Poor sleep is associated with an increased risk of infections and all-cause mortality but the causal direction between poor sleep and respiratory infections has remained unclear. We examined if poor sleep contributes as a causal risk factor to respiratory infections.

METHODS

We used data on insomnia, influenza and upper respiratory infections (URIs) from primary care and hospital records in the UK Biobank (N ≈ 231,000) and FinnGen (N ≈ 392,000). We computed logistic regression to assess association between poor sleep and infections, disease free survival hazard ratios, and performed Mendelian randomization analyses to assess causality.

FINDINGS

Utilizing 23 years of registry data and follow-up, we discovered that insomnia diagnosis associated with increased risk for infections (FinnGen influenza Cox's proportional hazard (CPH) HR = 4.34 [3.90, 4.83], P = 4.16 × 10-159, UK Biobank influenza CPH HR = 1.54 [1.37, 1.73], P = 2.49 × 10-13). Mendelian randomization indicated that insomnia causally predisposed to influenza (inverse-variance weighted (IVW) OR = 1.65, P = 5.86 × 10-7), URI (IVW OR = 1.94, P = 8.14 × 10-31), COVID-19 infection (IVW OR = 1.08, P = 0.037) and risk of hospitalization from COVID-19 (IVW OR = 1.47, P = 4.96 × 10-5).

INTERPRETATION

Our findings indicate that chronic poor sleep is a causal risk factor for contracting respiratory infections, and in addition contributes to the severity of respiratory infections. These findings highlight the role of sleep in maintaining sufficient immune response against pathogens.

FUNDING

Instrumentarium Science Foundation, Academy of Finland, Signe and Ane Gyllenberg Foundation, National Institutes of Health.

Adherence to CPAP in summer to autumn predicts self-reported common cold symptoms in patients with obstructive sleep apnea in winter: A prospective observational study

OBJECTIVE

We conducted a prospective observational study to determine the relationship between adherence to continuous positive airway pressure (CPAP) and susceptibility to the common cold in moderate-to-severe obstructive sleep apnea (OSA) patients.

METHODS

We prospectively investigated the number of days with common cold symptoms from November 2019 to February 2020. The rate of CPAP use for 4 h/night in the preceding four months (July to October 2019) was used as a measure of CPAP adherence. Multiple generalized linear models were used to evaluate the association to days of common cold symptoms after controlling for demographic variables, habitual short sleep duration, and insomnia severity.

RESULTS

We included 123 outpatients (median age 63 years) with moderate-to-severe OSA treated with CPAP. In the multivariate generalized linear model, better CPAP adherence was independently significantly associated with days with fewer common cold symptoms (β = -0.248, P = 0.031); meanwhile, the severity of insomnia and habitual short sleep duration was not significantly associated with it. Subgroup analyses revealed that the association between CPAP adherence and days with common cold symptoms was also significant in young to middle-aged (<65 years) participants (β = -0.407, P = 0.005). In contrast, the association was negligible in older (≥65 years) participants.

CONCLUSIONS

CPAP adherence may be protective against viral infections in patients with moderate-to-severe OSA. This effect appears to be more pronounced in young to middle-aged patients with OSA.

Risk Factors for Influenza-Induced Exacerbations and Mortality in Non-Cystic Fibrosis Bronchiectasis

Influenza infection is a cause of exacerbations in patients with chronic pulmonary diseases. The aim of this study was to investigate the clinical outcomes and identify risk factors associated with hospitalization and mortality following influenza infection in adult patients with bronchiectasis. Using the Chang Gung Research Database, we identified patients with bronchiectasis and influenza-related infection (ICD-9-CM 487 and anti-viral medicine) between 2008 and 2017. The main outcomes were influenza-related hospitalization and in-hospital mortality rate. Eight hundred sixty-five patients with bronchiectasis and influenza infection were identified. Five hundred thirty-six (62%) patients with bronchiectasis were hospitalized for influenza-related infection and 118 (22%) patients had respiratory failure. Compared to the group only seen in clinic, the hospitalization group was older, with more male patients, a lower FEV1, higher bronchiectasis aetiology comorbidity index (BACI), and more acute exacerbations in the previous year. Co-infections were evident in 55.6% of hospitalized patients, mainly caused by Pseudomonas aeruginosa (15%), fungus (7%), and Klebsiella pneumoniae (6%). The respiratory failure group developed acute kidney injury (36% vs. 16%; p < 0.001), and shock (47% vs. 6%; p < 0.001) more often than influenza patients without respiratory failure. The overall mortality rate was 10.8% and the respiratory failure group exhibited significantly higher in-hospital mortality rates (27.1% vs. 6.2%; p < 0.001). Age, BACI, and previous exacerbations were independently associated with influenza-related hospitalization. Age, presence of shock, and low platelet counts were associated with increased hospital mortality. Influenza virus caused severe exacerbation in bronchiectasis, especially in those who were older and who had high BACI scores and previous exacerbations. A high risk of respiratory failure and mortality were observed in influenza-related hospitalization in bronchiectasis. We highlight the importance of preventing or treating influenza infection in bronchiectasis.

The public health impact of poor sleep on severe COVID-19, influenza and upper respiratory infections

Background

Poor sleep is associated with an increased risk of infections and all-cause mortality, and acute sleep loss and disruption have been linked with inflammation and poorer immune control. Previous studies, however, have been unable to evidence causality between the chronic effects of poor sleep and respiratory infection risk. In light of the ongoing COVID-19 pandemic and potential future disease outbreaks, understanding the risk factors for these infections is of great importance.

Aim

Our goal was to understand if chronic poor sleep could be identified as a causal risk factor for respiratory infections including influenza, upper respiratory infections and COVID-19.

Methods

We used population cohorts from the UK Biobank (N ≈ 231,000) and FinnGen (N ≈ 327,000) with ICD-10 based electronic health records and obtained diagnoses of insomnia, influenza and upper respiratory infections (URIs) from primary care and hospital settings. We computed logistic regression to assess association between poor sleep and infections, disease free survival hazard ratios, and used summary statistics from genome-wide association studies of insomnia, influenza, URI and COVID-19 to perform Mendelian randomization analyses and assess causality.

Findings

Utilizing 23 years of registry data and follow-up, we saw that insomnia diagnosis associated with increased risk for infections in FinnGen and in UK Biobank (FinnGen influenza HR = 5.32 [4.09, 6.92], P = 1.02×10-35, UK Biobank influenza HR = 1.54 [1.37, 1.73], P = 2.49×10-13). Mendelian randomization indicated that insomnia causally predisposed to influenza (OR = 1.59, P = 6.23×10-4), upper respiratory infections (OR = 1.71, P = 7.60×10-13), COVID-19 infection (OR = 1.08, P = 0.037) and risk of hospitalization from COVID-19 (OR = 1.47, P = 4.96×10-5).

Conclusions

Our findings indicate that chronic poor sleep is a causal risk factor for contracting respiratory infections, and in addition contributes to the severity of respiratory infections. These findings highlight the role of sleep in maintaining sufficient immune response against pathogens as suggested by earlier work. As the current COVID-19 pandemic has increased the number of people suffering from poor sleep, safe interventions such as sleep management and treating individuals with insomnia could be promoted to reduce infections and save lives.

Sleep Apnea and Risk of Influenza-Associated Severe Acute Respiratory Infection: Real-World Evidence

PURPOSE

We executed the presented retrospective cohort study with the purpose of probing the risk of severe acute respiratory infection (SARI) following influenza in patients with sleep apnea.

MATERIALS AND METHODS

We executed this real-world study by gathering Taiwan National Health Insurance Research Database (NHIRD) data. From a database containing 1 million individuals sampled at random from the NHIRD, we identified all patients aged 20 years or older with a sleep apnea diagnosis between 1997 and 2013 as the study group. We established a comparison cohort of individuals without sleep apnea by randomly matching patients with respect to monthly income, gender, urbanization level, and age at a 1:4 ratio. Follow-up was performed until death or the end of 2015 for both groups. We determined the study outcome to be the occurrence of influenza-associated SARI.

RESULTS

We enrolled 6508 and 26,032 patients into the study and comparison groups, respectively. A significantly higher cumulative incidence of influenza-associated SARI was discovered in the study group (p < 0.001). In our multivariate analysis, sleep apnea, chronic obstructive pulmonary disease, and coronary artery disease were independent risk factors for influenza-associated SARI. The hazard ratio of sleep apnea for influenza-associated SARI was 1.98 (95% CI: 1.26-3.10) after adjustment for all comorbidities, gender, age, monthly income, and urbanization level.

CONCLUSION

Sleep apnea increased the risk of influenza-associated SARI. We suggest that physicians be cautious about the development of severe influenza illness in patients with sleep apnea. Vaccination and early oseltamivir administration should be actively considered in this group of patients.