Mortality in sleep apnea patients: a multivariate analysis of risk factors

Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease Overlap Syndrome

The coexistence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) in the same patients is defined as COPD/OSA overlap syndrome (OVL). OSA and sleep complaints are quite common among COPD patients and contribute to an increase in the risk of COPD exacerbation and mortality. Patients with OVL are more likely to develop cardiometabolic disease than patients with OSA or COPD alone. We must consider OSA as a treatable trait since the use of positive pressure ventilation reduces severe exacerbations, all-cause hospitalizations, and mortality in patients with COPD.

My voyage in the enchanted world of sleep

In this paper, I describe my 45-year career in sleep research. I started my undergraduate studies at Tel Aviv University, where I was first introduced to the enchanted world of sleep, continued to my graduate studies with Wilse B. Webb at the University of Florida, and then to post-doctoral training with Dan Kripke at the University of California at San Diego. Then, I describe the evolution of my academic career at the Technion-Israel Institute of Technology, where I started in 1975 as an Assistant Professor and retired in 2019 as the President of the Institute. I describe the areas of research that I pursued and how the research developed, emphasizing unexpected results that guided me and my lab team in new directions. This includes my early studies on ultradian rhythms, inspired by Nathaniel Kleitman's Basic Rest Activity Cyle hypothesis, utilizing the ultrashort sleep-wake paradigm to chart the 24-hour sleep propensity function, and how these studies led us to explore the role of melatonin in sleep regulation. I also explain why we directed our attention to sleep apnea, and how clinical observations led to the provocative hypothesis that sleep apnea-typically seen as a disorder-may also play a protective role. Under the leadership of my research partner and wife, Lena, we confirmed this hypothesis. Also in this article, I describe my enthusiasm for the history of our field and, as derived from my experience as a Dean of Medicine and President of a university, I share my philosophy about the role of members of academia in society. I emphasize that none of my achievements could have been accomplished without the hard work and motivation of my students and research partners, who shared my enthusiasm and passion for the enchanted world of sleep. This paper is part of the Living Legends in Sleep Research series, which is sponsored by Idorsia Pharmaceuticals and Jazz Pharmaceuticals.

Obstructive sleep apnoea-hypopnoea syndrome: state of the art

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is an extremely common sleep-related breathing disorder (SRBD) characterised by complete or partial collapse of the upper airways. These nocturnal phenomena cause high-frequency hypoxemic desaturations (or intermittent hypoxia, IH) during sleep and alterations in gas exchange. The result of IH is the development or worsening of cerebro-cardio-vascular, metabolic and other diseases, which cause a high risk of death. Hence, OSAHS is a multifactorial disease affecting several organs and systems and presenting with various clinical manifestations involving different medical branches. Although it has been estimated that about one billion individuals worldwide are affected by OSAHS, this SRBD remains underestimated also due to misinformation regarding both patients and physicians. Therefore, this review aims to provide information on the main symptoms and risk factors for the detection of individuals at risk of OSAHS, as well as to present the diagnostic investigations to be performed and the different therapeutic approaches. The scientific evidence reported suggest that OSAHS is an extremely common and complex disorder that has a large impact on the health and quality of life of individuals, as well as on healthcare expenditure. Moreover, given its multifactorial nature, the design and implementation of diagnostic and therapeutic programmes through a multidisciplinary approach are necessary for a tailor-made therapy for each patient.

Sleep position, patient comfort, and technical performance with two established procedures for home sleep testing

Purpose

In patients with a high pre-test probability of suffering from obstructive sleep apnea (OSA), (cardio)-respiratory polygraphy (RP; level 3) is commonly used for home sleep testing (HST); however, testing based on peripheral arterial tonometry (PAT) is increasingly recognized as an alternative method. The aim of the study was to compare sleep position, patients’ comfort, and technical failure rates of HST with RP and PAT in patients with suspected OSA.

Methods

Sleep position, patients’ comfort, and technical failure rates of RP and PAT were compared in 56 patients receiving two nights of HST with either RP or PAT in a randomized fashion.

Results

Time in supine position with PAT was significantly lower (173.7±88 min) compared to RP (181.7±103.7 min; p < 0.001), although the absolute mean difference was not clinically significant. Patients reported to sleep better, feeling less disturbed when falling asleep, losing less sensors, and fewer nightly awakenings with PAT, but experienced more pain at the side of the finger probe. Forty-five out of 56 patients (80%) rated PAT as being the superior sleep test and 49 out of 56 (88%) would prefer PAT for further investigations (p<0.001). PAT testing was associated with less technical failures.

Conclusion

The results demonstrate that HST with PAT leads to less time in supine sleep positioning, which may be clinically relevant in selected patients. Moreover, PAT is associated with less technical failures and is perceived with less discomfort during testing and a reduced number of nocturnal awakenings in patient self-reports.

The Effect of Gender and Sex Hormones on Cardiovascular Disease, Heart Failure, Diabetes, and Atrial Fibrillation in Sleep Apnea

Sleep apnea is a highly prevalent disorder with increasing impact on healthcare systems worldwide. Previous studies have been conducted primarily with male subjects, and prevalence and severity of sleep apnea in women are underestimated. Recent clinical and basic science evidence increasingly points to different mechanisms in men and women with sleep-disordered breathing (SDB). SDB is associated with a variety of comorbidities, including cardiovascular disease, heart failure, diabetes, and atrial fibrillation. In this review, we discuss sex-dependent mechanisms of SDB in select associated conditions to sharpen our clinical understanding of these sex-dependent inherent differences.

Probable Change of Sleep Parameters after Resection and Reconstruction Surgeries in Patients with Oral Cavity or Oropharyngeal Cancers

In patients of oral cavity or oropharyngeal cancers, resection of the tumor and reconstruction of the defect may reduce the framework, add a bulky flap, alter the tissue flexibility, and contribute to postoperative obstructive sleep apnea (OSA). Postoperative OSA and the potential consequences may decrease the survival rate and reduce patients' quality of life. It is unclear whether the surgery is associated with postoperative OSA. Here, we compared the polysomnographies (PSGs) before and after the surgery in 15 patients of oral cavity or oropharyngeal cancers (out of 68 patients of head and neck cancers) without a chemo- or radio-therapy. Each patient received the second PSG before the start of any indicated adjuvant therapy to prevent its interference. There were 14 men and 1 woman, with a mean age and a standard deviation (SD, same in the following) of 56.2 ± 12.8 years. There were 6 tongue cancers, 5 buccal cancers, 2 tonsil cancer, 1 lower gum cancer, and 1 trigone cancer. The results show that the surgery changed sleep parameters insignificantly in apnea-hypopnea index (AHI), mean oxyhemoglobin saturation of pulse oximetry (SpO2), minimum SpO2, mean desaturation, and desaturation index but increased mean heart rate in the patients with free flaps. These results hint that the effect of surgery on developing OSA was small in this sample, with a longer plate or a larger framework for a bulkier free flap. It needs future studies with a large sample size to generalize this first observation.

Prevalence and factors related to sleep apnoea in ankylosing spondylitis

An increased prevalence of obstructive sleep apnoea (OSA) has been suggested in patients with ankylosing spondylitis (AS) in a few controlled studies. We aimed to study the prevalence of OSA compared to controls and to investigate if disease-related and non-disease-related factors were determinants of OSA in AS patients. One hundred and fifty-five patients with AS were included in the Backbone study, a cross-sectional study that investigates severity and comorbidities in AS. Controls were recruited from the Swedish CArdioPulmonary bioImage Study. To evaluate OSA, the participants were asked to undergo home sleep-monitoring during one night’s sleep. For each AS patient 45–70 years old, four controls were matched for sex, age, weight, and height. OSA was defined as an apnoea-hypopnoea index (AHI) ≥ 5 events/hour. Sixty-three patients with AS were examined with home sleep-monitoring, and 179 controls were matched with 46 patients, 45–70 years. Twenty-two out of 46 (47.8%) patients with AS vs. 91/179 (50.8%) controls had OSA (AHI ≥ 5 events/hour), P = 0.72. No differences in the sleep measurements were noted in AS patients vs. controls. In logistic regression analysis adjusted for age and sex, higher age, higher BMI, and lesser chest expansion were associated with the presence of OSA in the 63 AS patients. In the current study, patients with AS did not have a higher prevalence of OSA compared to matched controls. AS patients with OSA had higher BMI, were older, and had lesser chest expansion because of more severe AS compared to patients without OSA.

Key points
• Patients with ankylosing spondylitis did not have a higher prevalence of obstructive sleep apnoea versus matched controls.
• Patients with ankylosing spondylitis and obstructive sleep apnoea were older and had higher body mass index versus patients without obstructive sleep apnoea.
• Patients with ankylosing spondylitis and obstructive sleep apnoea had lesser chest expansion versus patients without obstructive sleep apnoea.

Top 100 influential manuscripts in obstructive sleep apnea: a bibliometric analysis

OBJECTIVE

This study aimed to explore the characteristics of the top 100 influential manuscripts on obstructive sleep apnea (OSA).

METHODS

All manuscripts in English were searched from the Thomson Reuters Web of Science database by using OSA-related terms and ranked based on citation frequency. The top 100 influential manuscripts were selected and further analyzed by author, subject, journal, year of publication, country of origin, and institution.

RESULTS

A total of 42,878 manuscripts were searched from the Web of Science. The top 100 influential manuscripts were published from 2005 to 2017, with a total citation frequency of 38,463 and a median citation frequency of 303 (range: from 210 to 2, 707). The American Journal of Respiratory and Critical Care Medicine published the largest number of manuscripts from the top 100 (n = 18; 5340 citations), followed by Sleep (n = 11; 3516 citations) and Chest (n = 7; 1784 citations). The most cited manuscript (Marin, J.M et al., Lancet 2005; 2707 citations) mainly analyzed long-term cardiovascular outcomes in men with OSA with/without continuous positive airway pressure. The most prevalent subject was associated diseases (n = 41), followed by treatments (n = 40). Most of the manuscripts were original articles (n = 63) based on observational clinical studies and published from American institutions (n = 60).

CONCLUSIONS

Our study identified the top 100 influential manuscripts on OSA and provides insights into the characteristics of the most highly cited manuscripts to improve our understanding and management of OSA.

A review of sleep research in patients with spinal cord injury

Study design: Systematic review. Objectives: Sleep disturbances are a common complaint among individuals with spinal cord injury (SCI) and were not usually present before the SCI. Their sleep disturbances, including disrupted sleep, spasms, and problems with initiating and sustaining sleep through the night, affect SCI individuals' overall quality of life due to excessive tiredness and low energy levels during the day. Despite the high prevalence of sleep complaints in this population, current knowledge about sleep in the SCI population has not been systematically assessed. Setting: Capital Region of Denmark. Methods: We systematically reviewed literature identified from the PubMed and EMBASE databases following PRISMA guidelines.Thirty-seven articles met our inclusion criteria, as only controlled studies were included. This could be a comparison of (1) SCI individuals and able-bodied controls, (2) cervical with thoracolumbar SCI individuals, or (3) cervical, thoracolumbar SCI individuals and able-bodied controls. Results: Individuals with SCI have a higher prevalence of sleep-disordered breathing and periodic leg movements during sleep (PLMS), lower heart rate, but no nocturnal lowering of blood pressure. 24-hour energy expenditure and sleeping metabolic rate were significantly lower, and bowel movements were altered. Endocrine alterations were found in investigations of melatonin, cortisol and antidiuretic hormone. Questionnaires revealed a high prevalence of subjectively poorer sleep quality in individuals with SCI compared with able-bodied controls. Conclusions: There are significant differences between groups with SCI and able-bodied controls. SCI objectively and subjectively markedly affects an individual's sleep.

Eight-Year Follow-up of Modified Uvulopalatopharyngoplasty in Patients With Obstructive Sleep Apnea

OBJECTIVE

To investigate whether modified uvulopalatopharyngoplasty (UPPP) for treatment of obstructive sleep apnea (OSA) remained effective after 8 years.

METHODS

Prospective intervention study. Sixty-five patients with OSA were offered re-evaluation with polysomnography and the Epworth Sleepiness Scale (ESS) 8 years after UPPP. Results were compared with baseline and with a previous 2-year follow-up. Baseline predictors were analyzed with regression analyses.

RESULTS

The dropout rate at the 8-year follow-up was 28%. The mean decrease in apnea-hypopnea index (AHI) between baseline and the 8-year follow-up was significant, 14.0 events/hour (from 52.9 to 38.9), 27% (P < .001). The mean increase in AHI between the 2-year and the 8-year follow-up was significant, 14.7 events/hour (from 24.2 to 38.9), 61% (P < .0001). Overweight at baseline predicted an AHI at the 8-year follow-up that was 22.9 events higher compared to patients with normal weight (P = .015). An increase in body mass index (BMI) of 1 kg/m² between baseline and the 8-year follow-up predicted a mean AHI increase of 3.8 events/hour (P = .015). The median decrease in ESS between baseline and the 8-year follow-up was significant, 7 (from 13.0 to 6.0), 54% (P < .0001). The median increase in ESS between the 2-year and the 8-year follow-up was not significant, 1.0 (from 5.0 to 6.0), 20%.

CONCLUSION

Modified UPPP was effective as a long-term treatment for OSA in selected patients, although the effect on AHI decreased over time. Daytime sleepiness remained improved even in the long term. High BMI at baseline and an increase in BMI predicted a reduced long-term respiratory outcome.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E307-E313, 2021.

Nightly Hypoxia Does Not Seem to Lead to Otolith Dysfunction in Patients With Obstructive Sleep Apnea

OBJECTIVES

Obstructive sleep apnea (OSA) is a common sleep disorder, which is associated with recurrent oxygen desaturation during sleep. It has already been shown that nocturnal hypoxia may lead to cochlear dysfunction in patients with OSA. Less is known whether hypoxia during sleep also impacts vestibular function in those patients. Thus, the aim of the presented study was to assess a potential vestibulotoxic effect of nightly desaturations with hypoxia in patients with OSA by investigating a possible correlation between respiratory parameters and vestibular function tests.

METHODS

A total of 56 patients were included in the study and underwent a fully attended cardiorespiratory polysomnography (PSG). Vestibular function was assessed using video head impulse test to evaluate horizontal semicircular canal function and cervical vestibular evoked myogenic potentials (cVEMPs) and ocular vestibular evoked myogenic potentials (oVEMPs) to measure otolith function. Descriptive data analysis was conducted and correlation analysis between selected PSG parameters and the results of vestibular testing was performed using Kendall τ coefficient.

RESULTS

A significant correlation between vestibular function and respiratory polysomnographic parameters could not be demonstrated in the study (P > .05) but cVEMP and oVEMP results showed a trend toward a correlation with oxygen desaturation indices and apnea-hypopnea index. Additionally, otolith hypofunction was more prevalent in patients with hypertension as well as OSA.

CONCLUSION

The results of our study show that there is no significant correlation between vestibular function and sleep apnea parameters, although otolith dysfunction might be more prevalent in patients with OSA and hypertension.

Improving Practices for Selecting a Subset of Important Predictors in Psychology: An Application to Predicting Pain

Frequently, researchers in psychology are faced with the challenge of narrowing down a large set of predictors to a smaller subset. There are a variety of ways to do this, but commonly it is done by choosing predictors with the strongest bivariate correlations with the outcome. However, when predictors are correlated, bivariate relationships may not translate into multivariate relationships. Further, any attempts to control for multiple testing are likely to result in extremely low power. Here we introduce a Bayesian variable-selection procedure frequently used in other disciplines, stochastic search variable selection (SSVS). We apply this technique to choosing the best set of predictors of the perceived unpleasantness of an experimental pain stimulus from among a large group of sociocultural, psychological, and neurobiological (functional MRI) individual-difference measures. Using SSVS provides information about which variables predict the outcome, controlling for uncertainty in the other variables of the model. This approach yields new, useful information to guide the choice of relevant predictors. We have provided Web-based open-source software for performing SSVS and visualizing the results.

Circulating P-Selectin and Its Glycoprotein Ligand in Nondiabetic Obstructive Sleep Apnea Patients

Selectins and their ligands play an important role in atherosclerosis. The role of these adhesion molecules in the pathogenesis of obstructive sleep apnea (OSA) may be of clinical relevance. Therefore, the aim of this study was to assess the serum content of platelet P-selectin (P-SEL) and P-selectin glycoprotein ligand 1 (PSGL-1) in different OSA stages. The study was performed in nondiabetic patients, aged 32-71, in whom OSA was verified by polysomnography. The apnea/hypopnea index (AHI) was used to stratify OSA stages: AHI <5, no sleep pathology (OSA-0); AHI 5-15, (OSA-1); AHI 16-30, (OSA-2); and AHI >30, (OSA-3). There were 16 patients in each group. P-SEL and PSGL-1 were assessed by ELISA kits. There were no appreciable differences in the patients' glucose or high-specificity C-reactive protein content. We found that P-SEL and PSGL-1 significantly increased from OSA-0 to OSA-3. There were the following positive associations in all OSA patients: P-SEL vs. AHI, PSGL-1 vs. AHI, and P-SEL vs. PSGL-1. In addition, the adhesion molecules are associated with the anthropometric parameters, oxygen saturation, and sleep architecture in the OSA-1 group. We conclude that the adhesion molecules consistently increase in the blood of nondiabetic OSA patients, along with progression of disorder severity.

Long term management of obstructive sleep apnea and its comorbidities

Obstructive sleep apnea (OSA) is a worldwide highly prevalent disease associated with systemic consequences, including excessive sleepiness, impairment of neurocognitive function and daytime performance, including driving ability. The long-term sequelae of OSA include and increase risk for cardiovascular, cerebrovascular and metabolic syndrome disorders that ultimately lead to premature death if untreated. To ensure optimal long-term outcomes, the assessment and management of OSA should be personalized with the involvement of the appropriate specialist. Most studies have demonstrated inmediate improvement in daytime somnolence and quality of life with CPAP and other therapies, but the effect of long-term treatment on mortality is still under debate. Currently, the long-term management of OSA should be based on a) identifying physiological or structural abnormalities that are treatable at the time of patient evaluation and b) comprehensive lifestyle interventions, especially weight-loss interventions, which are associated with improvements in OSA severity, cardiometabolic comorbidities, and quality of life. In long-term management, attention should be paid to the clinical changes related to a potential reoccurrence of OSA symptoms and it is also necessary to monitor throughout the follow up how the main associated comorbidities evolve.

Oxidative Stress Markers and Severity of Obstructive Sleep Apnea

Oxidative stress underlies both obstructive sleep apnea (OSA) and atherosclerosis. The aim of the study was to assess the markers of oxidative stress in plasma at different stages of OSA in non-smoking obese Caucasian males aged 41-60, with normal oral glucose tolerance test. All patients were subjected to clinical and polysomnographic examinations. The stage of OSA severity was set according to the following criteria of the apnea-hypopnea index (AHI): AHI < 5/h - no disease (OSA-0; n = 26), AHI 5-15/h - mild disease (OSA-1; n = 26), AHI 16-30/h - moderate disease (OSA-2: n = 27), and AHI > 30/h obstructive episodes per hour - severe disease (OSA-3; n = 27). Plasma total antioxidant status (TAS) and thiobarbituric acid-reacting substances (TBARS), reflecting the level of lipid peroxides, were determined spectrophotometrically. We found that TAS decreased and TBARS increased significantly from OSA-0 to OSA-3. We conclude that the oxidative stress markers are conducive to setting the severity of OSA in normoglycemic patients.

The Overlap Syndrome

The overlap syndrome (OS) was first coined by David C. Flenley in 1985 to describe the coexistence of obstructive sleep apnea (OSA) in patients with chronic obstructive pulmonary disease (COPD). Patients with OS experience more profound nocturnal oxygen desaturation (NOD) than patients with OSA or COPD alone. This underlying hypoxia in OS increases the risk of cardiovascular disease including atrial fibrillation, right heart failure, and pulmonary hypertension, thereby increasing the mortality associated with the disease. Keeping in mind the risk of mortality, it is crucial for clinicians to clinically evaluate the patients with OSA or COPD for the occurrence of OS and provide effective treatment options for the same. This review aims to highlight the pathophysiology and the risks associated with the OS along with early detection and appropriate management protocols to reduce the mortality associated with it.

Sleep Apnea and Sleep-Disordered Breathing

Older adults undergo gradual changes in their sleep patterns. It is important to differentiate normal age-related sleep changes from sleep disorders. Because sleep disorders can impact an older adult's day-to-day life and contribute to various comorbidities, these patients should be carefully screened by using a detailed medical history, combined with a detailed sleep history. There is a high prevalence of undiagnosed and untreated sleep apnea in the elderly. Early identification and appropriate management of this disorder may not only provide improvement in quality of life but also decrease disease-associated morbidity and mortality.

Recognition of Sleep Apnea Is Increasing. Analysis of Trends in Two Large, Representative Databases of Outpatient Practice

RATIONALE

Little is known about recent trends in physician reporting of sleep apnea during outpatient practice visits.

OBJECTIVES

To assess trends in the frequency of adult outpatient visits for sleep apnea in the United States, the clinicians who provided those visits, and the characteristics of patients reported to have sleep apnea; and to assess whether the reporting of a diagnosis of sleep apnea varies across regions of the country as a function of body weight and insurance status.

METHODS

We reviewed annual stratified samples of patients identified as having sleep apnea during physician office visits in the U.S. National Ambulatory Medical Care Survey database, and during visits to hospital outpatient practices in the U.S. National Hospital Ambulatory Medical Care Survey database, between 1993 and 2010. The aggregate data set included records of 838,000 ambulatory practice visits.

MEASUREMENTS AND MAIN RESULTS

During this 17-year period, survey reports of a diagnosis of sleep apnea increased 14.6- fold, from 420,000 to 6.37 million per year (P = 0.0002). Thirty-three percent were reported by primary care providers, 17% by pulmonologists, and 10% by otolaryngologists. Over the period of observation, reports of a diagnosis of sleep apnea by "other groups" increased considerably (P < 0.001). The per capita rate of sleep apnea diagnoses per 1,000 persons per year differed across regions of the United States (P < 0.0001). Regions that reported a higher rate of sleep apnea appeared to be influenced by obesity (P < 0.001) and health insurance status (P < 0.005).

CONCLUSIONS

Diagnoses of sleep apnea during outpatient visits to hospital-based and non-hospital-based practices in the United States were much more frequent in 2010 than in 1993, as reported by outpatient practice clinicians participating in national surveys. Although the majority of diagnoses of sleep apnea were reported by primary care providers, pulmonologists, and otolaryngologists (60%), there was a substantial increase in reports of sleep apnea by clinicians practicing other specialties during the study period. Reporting of a diagnosis of sleep apnea varied by obesity prevalence and health insurance status across U.S. geographic regions.

Chronic obstructive pulmonary disease and sleep related disorders

PURPOSE OF REVIEW

Sleep related disorders are common and under-recognized in the chronic obstructive pulmonary disease (COPD) population. COPD symptoms can disrupt sleep. Similarly, sleep disorders can affect COPD. This review highlights the common sleep disorders seen in COPD patients, their impact, and potential management.

RECENT FINDINGS

Treatment of sleep disorders may improve quality of life in COPD patients. Optimizing inhaler therapy improves sleep quality. Increased inflammatory markers are noted in patients with the overlap syndrome of COPD and obstructive sleep apnea versus COPD alone. There are potential benefits of noninvasive positive pressure ventilation therapy for overlap syndrome patients with hypercapnia. Nocturnal supplemental oxygen may be beneficial in certain COPD subtypes. Nonbenzodiazepine hypnotic therapy for insomnia has shown benefit without associated respiratory failure or worsening respiratory symptoms. Melatonin may provide mild hypnotic and antioxidant benefits.

SUMMARY

This article discusses the impact of sleep disorders on COPD patients and the potential benefits of managing sleep disorders on respiratory disease control and quality of life.

Comorbidities and risk of mortality in patients with sleep apnea

BACKGROUND

A variety of disorders, most notably cardiovascular diseases, was linked to sleep apnea (SA), but their impact on mortality of SA patients had not been systematically investigated. We aimed to develop a composite index based on the comorbidity burden to predict mortality risk.

METHODS

Using Taiwan National Health Insurance Research Database, 9853 adult SA patients were enrolled and their comorbidity profile at baseline was recorded. The subjects were followed from 1995 till death or the end of 2011. A Cox regression model was used for multivariable adjustment to identify independent predictors for mortality.

RESULTS

During an average follow-up period of 5.3 ± 3.1 years, 311 (3.2%) subjects died. SA patients with any comorbidity had a higher risk for death compared to those without comorbidity (HR: 11.01, 95% CI 4.00-30.33, p < 0.001). Age and 10 comorbidities related to increased overall mortality were identified, from which the CoSA (Comorbidities of Sleep Apnea) index was devised. The corresponding hazard ratios for patients with CoSA index scores of 0, 1-3, 4-6, and >6 were 1 (reference), 3.29 (95% CI, 2.04-5.28, p < 0.001), 13.56 (95% CI, 8.63-21.33, p < 0.001), and 38.47 (95% CI, 24.92-59.38, p < 0.001), respectively.

CONCLUSIONS

Based on the comorbidity burden, we developed an easy-to-use tool to evaluate mortality risk in SA. Key messages: Sleep apnea (SA) is linked to a variety of disorders, particularly cardiovascular diseases. SA patients with any comorbidity may experience a higher risk of death in comparison to those without comorbidity. Comorbidities related to increased mortality are identified and converted into a simple risk indicator, the CoSA (Comorbidities of Sleep Apnea) index scores, which may help to stratify risk of death in daily practice.

A pictorial Sleepiness and Sleep Apnoea Scale to recognize individuals with high risk for obstructive sleep apnea syndrome

PURPOSE

The aim of this study was to evaluate the validity of a new pictorial form of a screening test for obstructive sleep apnea syndrome (OSAS) - the pictorial Sleepiness and Sleep Apnoea Scale (pSSAS). Validation was performed in a sample of patients admitted to sleep clinics in the UK and Switzerland.

PATIENTS AND METHODS

All study participants were investigated with objective sleep tests such as full-night-attended polysomnography or polygraphy. The pSSAS was validated by taking into account the individual result of the sleep study, sleep-related questionnaires and objective parameters such as body mass index (BMI) or neck circumference. Different scoring schemes of the pSSAS were evaluated, and an internal validation was undertaken.

RESULTS

The full data set consisted of 431 individuals (234 patients from the UK, 197 patients from Switzerland). The pSSAS showed good predictive performance for OSAS with an area under the curve between 0.77 and 0.81 depending on which scoring scheme was used. The subscores of the pSSAS had a moderate-to-strong correlation with widely used screening questionnaires for OSAS or excessive daytime sleepiness as well as with BMI and neck circumference.

CONCLUSION

The pSSAS can be used to select patients with a high probability of having OSAS. Due to its simple pictorial design with short questions, it might be suitable for screening in populations with low health literacy and in non-native English or German speakers.

A daytime obstructive sleep apnea severity assessment framework

Obstructive sleep apnea (OSA) is a prevalent sleep disorder characterized by repeated episodes of complete or partial blockage of the upper airway. These episodes can interfere with sound sleep and have fatal health consequences. They can also reduce the flow of oxygen to vital organs, like the brain, and lead to brain damage. In this paper, we leverage the correlation between brain damage and OSA to design a prediction framework that can assess the severity level of the OSA condition, as well as estimate the Apnea-Hypopnea Index (AHI) using only features obtained during wakefulness. Our daytime severity screening tool can enable the prioritization of patients for PSG studies based on the severity of their condition and can enable a more timely perioperative risk stratification. The proposed framework has a two-layered design that first classifies patients into coarse-grained OSA severity categories, before proceeding with the fine-grained AHI estimation within the classified category in the second layer. The performance of this framework was evaluated using the PSG's AHI scores as a gold standard. Using the proposed framework, patients can be classified into the correct severity group with 99.6% accuracy and their AHI can be estimated within an error of 4.5 events/hour, making the proposed system a promising reliable, daytime alternative for OSA severity screening.

Intermittent hypoxia initiated plasticity in humans: A multipronged therapeutic approach to treat sleep apnea and overlapping co-morbidities

Over the past three decades exposure to intermittent hypoxia (IH) has generally been considered a stimulus associated with a number of detrimental outcomes. However, there is sufficient evidence to link IH to many beneficial outcomes but they have largely been ignored, particularly in the field of sleep medicine in the United States. Recent reviews have postulated that this apparent contradiction is related to the severity and duration of exposure to IH; mild forms of IH initiate beneficial outcomes while severe forms of IH are coupled to detrimental consequences. In the present review we explore the role that IH has in initiating respiratory plasticity and the potential this form of plasticity has to mitigate obstructive sleep apnea (OSA) in humans. In taking this approach, we address the possibility that IH could serve as an adjunct therapy coupled with continuous positive airway pressure (CPAP) to treat OSA. Our working hypothesis is that exposure to mild IH leads to respiratory plasticity that manifests in increased stability of the upper airway, which could ultimately reduce the CPAP required to treat OSA. In turn, this reduction could increase CPAP compliance and extend the length of treatment each night, which might improve the magnitude of outcome measures. Improved treatment compliance coupled with the direct effect that IH has on numerous overlapping conditions (i.e. asthma, chronic obstructive pulmonary disease, spinal cord injury) may well lead to substantial improvements that exceed outcomes following treatment with CPAP alone. Overall, this review will consider evidence from the published literature which suggests that IH could serve as an effective multipronged therapeutic approach to treat sleep apnea and its overlapping co-morbidities.

Waist circumference and postmenopause stages as the main associated factors for sleep apnea in women: a cross-sectional population-based study

OBJECTIVE

The current study aimed to investigate stages of reproductive aging as an associated factor for obstructive sleep apnea syndrome (OSAS) among women in a representative sample of Sao Paulo, Brazil.

METHODS

Four hundred seven women underwent clinical evaluation, polysomnography, and biochemical analysis. Stages of reproductive aging were defined as premenopause, early postmenopause, and late postmenopause.

RESULTS

OSAS was more frequent in the postmenopausal groups, with 68.4% of women affected by severe OSAS belonging to the late postmenopause group. After adjustment for potential confounding factors, associated factors for OSAS, regardless of its severity, were waist circumference, modified Mallampati score IV, and both postmenopause stages. For moderate to severe OSAS and severe OSAS, we found waist circumference and both postmenopause stages to be the main factors. We carried out a receiver operating characteristic curve analysis, which demonstrated that the cutoff value for waist circumference was 87.5 cm, with a maximum of 75.7% accuracy for the classification of women as OSAS or non-OSAS.

CONCLUSIONS

OSAS is prevalent in postmenopausal women, especially in late postmenopause. This study highlights the association between waist circumference, early postmenopause and late postmenopause, and severity of OSAS. Our findings suggest that postmenopause stages may potentially exacerbate the presence of sleep disturbance and that reducing waist circumference may be an important strategy for managing OSAS in women.

How has our interest in the airway changed over 100 years?

Since the beginning of our specialty, our understanding of the link between function and facial growth and development has progressively improved. Today, we know that children with sleep-related breathing problems will often develop distinctive facial characteristics. In adults, sleep apnea can result in serious morbidity and mortality. Orthodontists can ask sleep-related questions in the health history to help identify sleep breathing disorders. Treating these patients presents unique opportunities for orthodontists to collaborate with other medical specialties to improve a patient's health and treatment outcome. Research presented in our Journal in the next century may shed new light that will help us better identify the problem and aid the specialty in developing more effective evidence-based treatment. Additional efforts are needed to understand the physiology, neurology, and genetics of sleep breathing disorders.

Social and behavioral predictors of insufficient sleep among African Americans and Caucasians

BACKGROUND

Few studies have examined the social and behavioral predictors of insufficient sleep.

OBJECTIVE

To assess the social and behavioral predictors of insufficient sleep in the U.S.

METHODS

Data from the 2009 Behavioral Risk Factor Surveillance System (BRFSS) were analyzed. Telephone interviews were conducted in six representative states that completed the optional sleep module. A total of 31,059 respondents were included in the present analysis. BRFSS-provided weights were applied to analyses to adjust for the use of complex design.

RESULTS

The mean age for the sample was 56 ± 16 years, with 63% of the sample being female; 88% identified as non-Hispanic white and 12% identified as non-Hispanic black; 42% were not married and 8% did not have a high school degree. The prevalence of insufficient sleep (<7 hours) was 37%. Multivariate-adjusted logistic regression revealed associations of four important factors with insufficient sleep, which were: working more than 40 hours per week [OR = 1.65, p < 0.001, 95% CI = 1.65-1.66], black race/ethnicity [OR = 1.37, p < 0.001, 95% CI = 1.37-1.38], history of heart disease [OR = 1.26, p < 0.001, 95% CI = 1.25-1.28], care-giving to family/friends [OR = 1.50, p < 0.001, 95% CI = 1.49-1.51], and lack of social and emotional support [OR = 1.24, p < 0.001, 95% CI = 1. 23-1.25].

CONCLUSION

Social and behavioral predictors of health uniquely contribute to the report of insufficient sleep and should be considered when developing programs to increase awareness of the adverse effects of insufficient sleep.

A community-oriented framework to increase screening and treatment of obstructive sleep apnea among blacks

OBJECTIVE

Obstructive sleep apnea (OSA) is a leading sleep disorder that is disproportionately more prevalent in minority populations and is a major risk factor for cardiovascular disease (CVD) morbidity and mortality. OSA is associated with many chronic conditions including hypertension, diabetes, and obesity, all of which are disproportionately more prevalent among blacks (ie, peoples of African American, Caribbean, or African descent).

METHODS

This article reviews studies conducted in the United States (US) that investigated sleep screenings and adherence to treatment for OSA among blacks. In addition, guidelines are provided for implementing a practical framework to increase OSA screening and management among blacks.

RESULTS

Several studies have documented racial/ethnic disparities in adherence to treatment for OSA. However, despite its public health significance, there is a paucity of studies addressing these disparities. Further, there is a lack of health programs and policies to increase screening and treatment of OSA among blacks and other minority populations. A practical framework to increase the number of blacks who are screened for OSA and treated appropriately is warranted. Such a framework is timely and major importance, as early identification of OSA in this high-risk population could potentially lead to early treatment and prevention of CVD, thereby reducing racial and ethnic disparities in sleep-related CVD morbidity and mortality.

Is Mixed Apnea Associated with Non-Rapid Eye Movement Sleep a Reversible Compensatory Sign of Heart Failure?

Patient: Male, 24

Final Diagnosis: Dilated cardiomyopathy

Symptoms: Biventricular heart failure • sleep apnea

Medication: —

Clinical Procedure: Heart transplantation

Specialty: Cardiology

Obstructive sleep apnea is a common disorder in the population-a review on the epidemiology of sleep apnea

The prevalence of obstructive sleep apnea (OSA) defined at an apnea-hypopnea index (AHI) ≥5 was a mean of 22% (range, 9-37%) in men and 17% (range, 4-50%) in women in eleven published epidemiological studies published between 1993 and 2013. OSA with excessive daytime sleepiness occurred in 6% (range, 3-18%) of men and in 4% (range, 1-17%) of women. The prevalence increased with time and OSA was reported in 37% of men and in 50% of women in studies from 2008 and 2013 respectively. OSA is more prevalent in men than in women and increases with age and obesity. Smoking and alcohol consumption are also suggested as risk factors, but the results are conflicting. Excessive daytime sleepiness is suggested as the most important symptom of OSA, but only a fraction of subjects with AHI >5 report daytime sleepiness and one study did not find any relationship between daytime sleepiness and sleep apnea in women. Stroke and hypertension and coronary artery disease are associated with sleep apnea. Cross-sectional studies indicate an association between OSA and diabetes mellitus. Patients younger than 70 years run an increased risk of early death if they suffer from OSA. It is concluded that OSA is highly prevalent in the population. It is related to age and obesity. Only a part of subjects with OSA in the population have symptoms of daytime sleepiness. The prevalence of OSA has increased in epidemiological studies over time. Differences and the increase in prevalence of sleep apnea are probably due to different diagnostic equipment, definitions, study design and characteristics of included subjects including effects of the obesity epidemic. Cardiovascular disease, especially stroke is related to OSA, and subjects under the age of 70 run an increased risk of early death if they suffer from OSA.

On the cutting edge of obstructive sleep apnoea: where next?

Obstructive sleep apnoea is a common disease that is now more widely recognised because of the rise in prevalence and the increasingly compelling data that shows major neurocognitive and cardiovascular sequelae. At the same time, the clinical practice of sleep medicine is changing rapidly, with novel diagnostics and treatments that have established a home-based (rather than laboratory-based) management approach. We review the most recent insights and discoveries in obstructive sleep apnoea, with a focus on diagnostics and therapeutics. As will be discussed, management of obstructive sleep apnoea could soon transition from a so-called one size fits all approach to an individualised approach.

When obesity and chronic obstructive pulmonary disease collide. Physiological and clinical consequences

In many parts of the world, the prevalence of both chronic obstructive pulmonary disease (COPD) and obesity is increasing at an alarming rate. Such patients tend to have greater respiratory symptoms, more severe restriction of daily activities, poorer health-related quality of life, and greater health care use than their nonobese counterparts. Physiologically, increasing weight gain is associated with lung volume reduction effects in both health and disease, and this should be considered when interpreting common pulmonary function tests where lung volume is the denominator, such as FEV1/FVC and the ratio of diffusing capacity of carbon monoxide to alveolar volume, or indeed when evaluating the physiological consequences of emphysema in obese individuals. Contrary to expectation, the presence of mild to moderate obesity in COPD appears to have little deleterious effect on respiratory mechanics and muscle function, exertional dyspnea, and peak symptom-limited oxygen uptake during cardiopulmonary exercise testing. Thus, in evaluating obese patients with COPD reporting activity restriction, additional nonpulmonary factors, such as increased metabolic loading, cardiocirculatory impairment, and musculoskeletal abnormalities, should be considered. Care should be taken to recognize the presence of obstructive sleep apnea in obese patients with COPD, as effective treatment of the former condition likely conveys an important survival advantage. Finally, morbid obesity in COPD presents significant challenges to effective management, given the combined effects of erosion of the ventilatory reserve and serious metabolic and cardiovascular comorbidities that collectively predispose to an increased risk of death from respiratory failure.

Assessment of Snoring and obstructive sleep apnoea in a Nigerian university: Association with cardiovascular risk factors

BACKGROUND

Snoring remains under diagnosed in general population. It however has significant morbidity and mortality risk factors with multiple effects on the cardiovascular system. The Berlin questionnaire is a worldwide validated instrument to identify those at increased risk for obstructive sleep apnoea (OSA).

MATERIALS AND METHODS

In all, 206 workers of LAUTECH were invited to participate in the study. The Berlin questionnaire was used for this study. It was a cross-sectional study. Socio-demographic and clinical data were taken with a data form. Statistical Package for the Social Sciences software (SPSS 17.0) was used for statistical analysis. P < 0.05 was taken as statistically significant value.

RESULTS

The study participants consisted of 96 males (46.6%) and 110 (53.4%) females. The mean age was 45.3 ± 7.9 years. The mean body mass index was 28.5 ± 6.0 kg/m². The frequency of occurrence of snoring was 91 (44.2%) including 50 males (54.9% and 41 females (37.3 %, P <0.05). Using the Berlin score, 63 (30.6%) including 34 females (30.9%) were assessed to be at high risk for OSA. Snorers were more likely to be at higher risk of OSA compared to non snorers: odd risk was 113.8, relative risk was 3.3. Snoring was most likely to be associated with obesity, elevated blood pressure and male gender in this study.

CONCLUSION

We concluded that snoring and high risk for sleep apnoea is common among this unselected University population and they are closely related to many conventional cardiovascular risk factors. Appropriate interventional strategies are indicated to reduce the burden of the increased morbidity and mortality associated with sleep apnoea in our population.

Major factors affecting severity of obstructive sleep apnea

Computed tomography (CT) has become a common method for evaluating obstructive sleep apnea (OSA). The aim of this study was to analyze the relationships between CT parameters and clinical parameters in OSA patients to determine major factors affecting the severity of OSA. The records of 128 consecutive snoring patients (98 males, 30 females) diagnosed with OSA were retrospectively reviewed. Polysomnography was performed for each patient. On CT scans, airway areas were measured at the level of the hard palate, the soft palate, and the base of the tongue. Polysomnographic parameters were compared by gender and age using the Mann-Whitney U test. Pearson's correlation coefficient was used to analyze relationships between variables and the AHI in each age group. The women were significantly older than the men (p < 0.01). The AHI and apnea index were significantly higher in men than in women. Stage 1 sleep and rapid eye movement sleep were more frequent in men than in women. The area at the base of the tongue was significantly smaller in women than in men (p = 0.027). In the 50-60 age group, the AHI was significantly higher in men (41.47 ± 19.67) than in women (17.14 ± 15.63) (p = 0.001). OSA severity varies with age, gender, and upper airway area. The OSA prognosis could be improved by evaluating the major factors and treating OSA patients according to epidemiological characteristics and anatomical structures.

Attenuated macrophage cholesterol efflux function in patients with obstructive sleep apnea-hypopnea syndrome

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with premature atherosclerosis. However, the associated mechanism remains unknown. This study investigates the expression of adenosine triphosphate (ATP)-binding cassette transporter protein A1 (ABCA1) and cellular cholesterol efflux in cultured macrophages from OSAHS patients.

METHODS

Of the 18 subjects enrolled in this study, six subjects with apnea-hypopnea index (AHI) <5 were placed into the control group, and 12 subjects with AHI ≥5 were placed into the OSAHS group. Peripheral blood mononuclear cells (PBMCs) from each subject were isolated, purified, cultured, and differentiated into macrophages in vitro. ABCA1 mRNA and protein expression were evaluated by reverse transcription PCR and Western Blot, respectively. Both ABCA1-mediated and autologous serum induced cholesterol efflux were measured by isotopic cholesterol efflux assays.

RESULTS

The levels of AHI and high sensitivity C-reactive protein (hsCRP) were significantly higher in the OSAHS group than in the control group. ABCA1 mRNA and protein expressions in PBMCs-derived macrophages were significantly reduced in patients with OSAHS compared to that in controls (p < 0.05). Both ABCA1-mediated and autologous serum-induced cholesterol efflux were significantly lower in the OSAHS group than that in the control group (p = 0.033 and p = 0.01, respectively). Pearson's correlation analysis revealed a negative correlation between AHI and the mRNA (r = -0.7726, p = 0.0007) and protein (r = -0.8112, p = 0.0044) expression of ABCA1, a positive correlation between ABCA1-mediated cholesterol efflux and the minimum oxygen saturation (r = 0.7954, p < 0.0001), and a negative correlation between AHI and autologous serum induced cholesterol efflux (r = -0.7756, p = 0.0002).

CONCLUSION

ABCA1 expression and cellular cholesterol efflux in macrophages were significantly decreased in OSAHS patients, which closely correlated with the severity of disease. Our findings provide meaningful insights into the mechanism of atherogenesis in OSAHS patients.

Evaluation and validation of a method for determining platelet catecholamine in patients with obstructive sleep apnea and arterial hypertension

Background

Measurements of plasma and urinary catecholamine are susceptible to confounding factors that influence the results, complicating the interpretation of sympathetic nervous system (SNS) activity in the Obstructive sleep apnea (OSA) and arterial hypertension (HYP) conditions.

Objective

In this study, we validated a test for platelet catecholamine and compared the catecholamine levels (adrenaline and noradrenaline) in urine, plasma and platelets in patients with OSA and HYP compared with controls.

Methods

In the validation, 30 healthy, nonsmoking volunteers who were not currently undergoing treatment or medication were selected as the control group. One hundred fifty-four individuals (114 OSA, 40 non-OSA) were consecutively selected from the outpatient clinic of the Sleep Institute and underwent clinical, polysomnographic and laboratory evaluation, including the urinary, plasma and platelet levels of adrenaline (AD) and noradrenaline (NA). Patients were then allocated to groups according to the presence of OSA and/or hypertension.

Results

A logistic regression model, controlled for age and BMI, showed that urinary AD and urinary NA were risk factors in the OSA+HYP group and the HYP group; however, the model showed higher levels of platelet NA for OSA without HYP. After 1 year of CPAP (continuous upper airway pressure) treatment, patients (n = 9) presented lower levels of urinary NA (p = 0.04) and platelet NA (p = 0.05).

Conclusion

Urinary NA and AD levels were significantly associated with the condition of hypertension with and without OSA, whereas platelet NA with OSA without comorbidity. These findings suggest that platelet catecholamine levels might reflect nocturnal sympathetic activation in OSA patients without hypertension.

New insights into the management of rhythm and conduction disorders after acute myocardial infarction

PATIENT

Male, 53 FINAL DIAGNOSIS: Myocardial infarction Symptoms: Chest pain • tachycardia

MEDICATION

- Clinical Procedure: - Specialty: Cardiology.

OBJECTIVE

Challenging differential diagnosis.

BACKGROUND

Comorbidities, including obesity and sleep-breathing disorders, can adversely influence outcomes in acute myocardial infarction (AMI), and should be considered in diagnosis and treatment administration.

CASE REPORT

The case demonstrates the difficulties of treating a middle-aged Caucasian patient with multiple comorbidities that could be overcome by a personalized approach and evaluation of concomitant sleep-breathing disorders (by polysomnography study). Diagnosis and treatment of sleep apnea by positive airway pressure (PAP therapy) played a pivotal role in heart rate and rhythm control.

CONCLUSIONS

In this case, effective PAP therapy enabled titration of antiarrhythmic drugs (to maximal doses) to achieve heart rate control and to eliminate severe ventricular tachyarrhythmias and contributed to the better recovery in a post-AMI patient with left ventricular systolic dysfunction.

Sleep apnea and 20-year follow-up for all-cause mortality, stroke, and cancer incidence and mortality in the Busselton Health Study cohort

OBJECTIVE

To ascertain whether objectively measured obstructive sleep apnea (OSA) independently increases the risk of all cause death, cardiovascular disease (CVD), coronary heart disease (CHD), stroke or cancer.

DESIGN

Community-based cohort.

SETTING AND PARTICIPANTS

400 residents of the Western Australian town of Busselton.

MEASURES

OSA severity was quantified via the respiratory disturbance index (RDI) as measured by a single night recording in November-December 1990 using the MESAM IV device, along with a range of other risk factors. Follow-up for deaths and hospitalizations was ascertained via record linkage to the end of 2010.

RESULTS

We had follow-up data in 397 people and then removed those with a previous stroke (n = 4) from the mortality/ CVD/CHD/stroke analyses and those with cancer history from the cancer analyses (n = 7). There were 77 deaths, 103 cardiovascular events (31 strokes, 59 CHD) and 125 incident cases of cancer (39 cancer fatalities) during 20 years follow-up. In fully adjusted models, moderate-severe OSA was significantly associated with all-cause mortality (HR = 4.2; 95% CI 1.9, 9.2), cancer mortality (3.4; 1.1, 10.2), incident cancer (2.5; 1.2, 5.0), and stroke (3.7; 1.2, 11.8), but not significantly with CVD (1.9; 0.75, 4.6) or CHD incidence (1.1; 0.24, 4.6). Mild sleep apnea was associated with a halving in mortality (0.5; 0.27, 0.99), but no other outcome, after control for leading risk factors.

CONCLUSIONS

Moderate-to-severe sleep apnea is independently associated with a large increased risk of all-cause mortality, incident stroke, and cancer incidence and mortality in this community-based sample.

Update on obstructive sleep apnea and its relation to COPD

Chronic obstructive pulmonary disease (COPD) is a common and preventable lung disease that affects millions of people in the United States. Sleep disorders including obstructive sleep apnea (OSA) are also common. It is not surprising that many people with COPD also suffer from OSA. This relationship, however, puts people at risk for more nocturnal desaturations and potential complications related to this, including pulmonary hypertension and heart rhythm disturbances. This update focuses on the physiology of sleep disturbances in COPD as well as the clinical implications of OSA in COPD.