Obstructive sleep apnoea in the general population: highly prevalent but minimal symptoms

Verbal memory is linked to average oxygen saturation during sleep, not the apnea-hypopnea index nor novel hypoxic load variables

INTRODUCTION

The apnea-hypopnea index (AHI) is the current diagnostic parameter for diagnosing and estimating the severity of obstructive sleep apnea (OSA). It is, however, poorly associated with the main clinical symptom of OSA, excessive daytime sleepiness, and with the often-seen cognitive decline among OSA patients. To better evaluate OSA severity, novel hypoxic load parameters have been introduced that consider the duration and depth of oxygen saturation drops associated with apneas or hypopneas. The aim of this paper was to compare novel hypoxic load parameters and traditional OSA parameters to verbal memory and executive function in OSA patients.

METHOD

A total of 207 adults completed a one-night polysomnography at sleep laboratory and two neuropsychological assessments, the Rey Auditory Verbal Learning Test and Stroop test.

RESULTS

Simple linear regression analyses were used to evaluate independent associations between each OSA parameter and cognitive performance. Associations were found between immediate recall and arousal index, hypoxia <90 %, average SpO2 during sleep, and DesSev100+RevSev100. Total recall was associated with all OSA parameters, and no associations were found with the Stroop test. Subsequently, sex, age, and education were included as covariates in multiple linear regression analyses for each OSA parameter and cognitive performance. The main findings of the study were that average SpO2 during sleep was a significant predictor of total recall (p < .007, β = -.188) with the regression model explaining 21.2 % of performance variation. Average SpO2 during sleep was also a significant predictor of immediate recall (p < .022, β = -.171) with the regression model explaining 11.4 % of performance variation. Neither traditional OSA parameters nor novel hypoxic load parameters predicted cognitive performance after adjustment for sex, age, and education.

CONCLUSION

The findings validate that the AHI is not an effective indicator of cognitive performance in OSA and suggest that average oxygen saturation during sleep may be the strongest PSG predictor of cognitive decline seen in OSA. The results also underline the importance of considering age when choosing neurocognitive tests, the importance of including more than one test for each cognitive domain as most tests are not pure measures of a single cognitive factor, and the importance of including tests that cover all cognitive domains as OSA is likely to have diffuse cognitive effects.

Association between triglyceride glucose-body mass index and obstructive sleep apnea: a study from NHANES 2015-2018

Background

The association between TyG-BMI index and the risk of obstructive sleep apnea (OSA), a recently identified biomarker indicating insulin resistance, has yet to be elucidated. Therefore, this study aimed to investigate the association between TyG-BMI index and the risk of OSA using the NHANES database.

Methods

Analyses were performed on NHANES data conducted between 2015 and 2018. Logistic regression, stratified analyses, curve-fitting analyses, and threshold effects analyses were utilized to assess the association between TyG-BMI index and the risk of OSA.

Results

The study included 4,588 participants. Multifactorial logistic regression analyses found a significant association between TyG-BMI and increased risk of OSA [OR: 1.54 (CI:1.39-1.70)]. In stratified analyses, age interacted with the association, with TyG-BMI being associated with increased risk of OSA only in a subgroup of subjects younger than 60 years [1.31 (1.14-1.50)], but gender, smoking status, and alcohol use, did not influence the association. The presence of diabetes, hypertension, and cardiovascular diseases also modified the association, but the number of the included subjects with such conditions was significantly lower, therefore the significance of associations was not observed in those subgroups. Additionally, the risk was non-linearly associated, with the inflection point of TyG-BMI at 12.09, after which the lower slope in the risk was observed.

Conclusion

This study demonstrates that elevated levels of the TyG-BMI index are correlated with risk for OSA, underscoring the significance of these findings in facilitating early prevention or timely intervention for OSA.

Flow Limitation Is Associated with Excessive Daytime Sleepiness in Individuals without Moderate or Severe Obstructive Sleep Apnea

Rationale: Moderate-severe obstructive sleep apnea (OSA) (apnea-hypopnea index [AHI], >15 events/h) disturbs sleep through frequent bouts of apnea and is associated with daytime sleepiness. However, many individuals without moderate-severe OSA (i.e., AHI <15 events/h) also report sleepiness. Objectives: To test the hypothesis that sleepiness in the AHI <15 events/h group is a consequence of substantial flow limitation in the absence of overt reductions in airflow (i.e., apnea/hypopnea). Methods: A total of 1,886 participants from the MESA sleep cohort were analyzed for frequency of flow limitation from polysomnogram-recorded nasal airflow signal. Excessive daytime sleepiness (EDS) was defined by an Epworth Sleepiness Scale score ⩾11. Covariate-adjusted logistic regression assessed the association between EDS (binary dependent variable) and frequency of flow limitation (continuous) in individuals with an AHI <15 events/h. Results: A total of 772 individuals with an AHI <15 events/h were included in the primary analysis. Flow limitation was associated with EDS (odds ratio, 2.04; 95% confidence interval, 1.17-3.54; per 2-standard deviation increase in flow limitation frequency) after adjusting for age, sex, body mass index, race/ethnicity, and sleep duration. This effect size did not appreciably change after also adjusting for AHI. Conclusions: In individuals with an AHI <15 events/h, increasing flow limitation frequency by 2 standard deviations is associated with a twofold increase in the risk of EDS. Future studies should investigate addressing flow limitation in low-AHI individuals as a potential mechanism for ameliorating sleepiness.

Validation of Trøndelag Apnoea Score Proxy for Obstructive Sleep Apnoea in the General Population of Norway: The HUNT Study

The aim was to validate a new seven-item "TASC" (Trøndelag Apnoea Score) proxy for obstructive sleep apnoea (OSA) against polysomnography in the general population. Objectives included validation against different polysomnographic criteria, stratification by age and gender, and estimation of OSA prevalence. From the fourth wave of the Trøndelag Health Study (HUNT4), 1,201 participants were randomly invited to a substudy focusing on sleep and headaches, of whom 232 accepted and 84 (64% women, mean age 55.0 years, and standard deviation 11.5 years) underwent polysomnography. The TASC proxy sums seven binary items for snoring, observed breathing pauses, restricted daytime activities, hypertension, body mass index (≥30 kg/m2), age (≥50 years), and gender (male). A single night of ambulatory (home) polysomnography was analysed using both the recommended and optional hypopnoea criteria of the American Academy of Sleep Medicine (AASM). We found 65% sensitivity and 87% specificity (Cohen's κ = 0.53, 95% confidence interval 0.34-0.72) for TASC ≥ 3 against AHI ≥ 15 (recommended AASM criteria). Validity was similar against AHI ≥ 30 but lower against AHI ≥ 5 and against the optional AASM criteria. Sensitivity and overall validity were higher among men and those above 50 years of age. The prevalence of an apnoea-hypopnoea index (AHI) of at least 5, 15, or 30 using the recommended (and optional) AASM criteria was 73% (46%), 37% (18%), or 15% (5%). A seven-item TASC proxy for OSA showed good validity and may be useful in screening and epidemiological settings. Sensitivity, specificity, and validity vary considerably by cut-off, by polysomnographic scoring criteria, and by gender and age strata.

Elucidating the association of obstructive sleep apnea with brain structure and cognitive performance

BACKGROUND

Obstructive sleep apnea (OSA) is a pervasive, chronic sleep-related respiratory condition that causes brain structural alterations and cognitive impairments. However, the causal association of OSA with brain morphology and cognitive performance has not been determined.

METHODS

We conducted a two-sample bidirectional Mendelian randomization (MR) analysis to investigate the causal relationship between OSA and a range of neurocognitive characteristics, including brain cortical structure, brain subcortical structure, brain structural change across the lifespan, and cognitive performance. Summary-level GWAS data for OSA from the FinnGen consortium was used to identify genetically predicted OSA. Data regarding neurocognitive characteristics were obtained from published meta-analysis studies. Linkage disequilibrium score regression analysis was employed to reveal genetic correlations between OSA and related traits.

RESULTS

Our MR study provided evidence that OSA was found to significantly increase the volume of the hippocampus (IVW β (95% CI) = 158.997 (76.768 to 241.227), P = 1.51e-04), with no heterogeneity and pleiotropy detected. Nominally causal effects of OSA on brain structures, such as the thickness of the temporal pole with or without global weighted, amygdala structure change, and cerebellum white matter change covering lifespan, were observed. Bidirectional causal links were also detected between brain cortical structure, brain subcortical, cognitive performance, and OSA risk. LDSC regression analysis showed no significant correlation between OSA and hippocampus volume.

CONCLUSIONS

Overall, we observed a positive association between genetically predicted OSA and hippocampus volume. These findings may provide new insights into the bidirectional links between OSA and neurocognitive features, including brain morphology and cognitive performance.

Mild-to-moderate obstructive sleep apnea and mortality risk in a general population sample: The modifying effect of age and cardiovascular/cerebrovascular comorbidity

About 5.4%-45.7% of the general population has mild-to-moderate obstructive sleep apnea (mmOSA), which is highly comorbid with cardiovascular and/or cerebrovascular diseases (CBVD). We examined the association between mmOSA and all-cause mortality and the modifying effect of age and CBVD. A total of 1681 adults 20-88 years old from the Penn State Adult Cohort (PSAC) (41.9% male) were followed up for 20.1 ± 6.2 years for all-cause mortality. Mild and moderate OSA were defined as an apnea/hypopnea index (AHI) 5-14.9 and 15-29.9 events/hour, respectively. CBVD was defined as a report of a physician diagnosis or treatment for heart disease and/or stroke. Cox proportional hazards regression models were used to estimate all-cause mortality adjusted for confounders. All-cause mortality risk was significantly increased in the mmOSA group in young and middle-aged adults (<60 years) (HR = 1.59, 95%CI 1.08-2.04) but not in older adults (≥60 years) (HR = 1.05, 95%CI 0.80-1.39). A synergistic effect between mmOSA and CBVD was stronger in those <60 years (HR = 3.82, 95%CI 2.25-6.48 in <60 years vs 1.86 95%CI 1.14-3.04 in ≥60 years). There was an additive effect between moderate OSA and hypertension in <60 but not in those ≥60 years. Mild OSA was associated with all-cause mortality only in the presence of CBVD. Mortality risk is increased in young and middle-aged adults with moderate OSA, whereas the mortality risk associated with mild OSA is elevated only, regardless of age, in the presence of comorbid CBVD. AHI cut-offs warranting treatment of mmOSA may need to be adjusted based on age and comorbidities.

Polysomnographic characteristics of excessive daytime sleepiness phenotypes in obstructive sleep apnea: results from the international sleep apnea global interdisciplinary consortium

STUDY OBJECTIVES

Excessive daytime sleepiness (EDS) is a major symptom of obstructive sleep apnea (OSA). Traditional polysomnographic (PSG) measures only partially explain EDS in OSA. This study analyzed traditional and novel PSG characteristics of two different measures of EDS among patients with OSA.

METHODS

Sleepiness was assessed using the Epworth Sleepiness Scale (>10 points defined as "risk of dozing") and a measure of general sleepiness (feeling sleepy ≥ 3 times/week defined as "feeling sleepy"). Four sleepiness phenotypes were identified: "non-sleepy," "risk of dozing only," "feeling sleepy only," and "both at risk of dozing and feeling sleepy."

RESULTS

Altogether, 2083 patients with OSA (69% male) with an apnea-hypopnea index (AHI) ≥ 5 events/hour were studied; 46% were "non-sleepy," 26% at "risk of dozing only," 7% were "feeling sleepy only," and 21% reported both. The two phenotypes at "risk of dozing" had higher AHI, more severe hypoxemia (as measured by oxygen desaturation index, minimum and average oxygen saturation [SpO2], time spent < 90% SpO2, and hypoxic impacts) and they spent less time awake, had shorter sleep latency, and higher heart rate response to arousals than "non-sleepy" and "feeling sleepy only" phenotypes. While statistically significant, effect sizes were small. Sleep stages, frequency of arousals, wake after sleep onset and limb movement did not differ between sleepiness phenotypes after adjusting for confounders.

CONCLUSIONS

In a large international group of patients with OSA, PSG characteristics were weakly associated with EDS. The physiological measures differed among individuals characterized as "risk of dozing" or "non-sleepy," while "feeling sleepy only" did not differ from "non-sleepy" individuals.

Identifying clusters of patient comorbidities associated with obstructive sleep apnea using electronic health records

STUDY OBJECTIVES

The objectives of this study were to understand the relative comorbidity burden of obstructive sleep apnea (OSA), determine whether these relationships were modified by sex or age, and identify patient subtypes defined by common comorbidities.

METHODS

Cases with OSA and noncases (controls) were defined using a validated electronic health record (EHR)-based phenotype and matched for age, sex, and time period of follow-up in the EHR. We compared prevalence of the 20 most common comorbidities between matched cases and controls using conditional logistic regression with and without controlling for body mass index. Latent class analysis was used to identify subtypes of OSA cases defined by combinations of these comorbidities.

RESULTS

In total, 60,586 OSA cases were matched to 60,586 controls (from 1,226,755 total controls). Patients with OSA were more likely to have each of the 20 most common comorbidities compared with controls, with odds ratios ranging from 3.1 to 30.8 in the full matched set and 1.3 to 10.2 after body mass index adjustment. Associations between OSA and these comorbidities were generally stronger in females and patients with younger age at diagnosis. We identified 5 distinct subgroups based on EHR-defined comorbidities: High Comorbidity Burden, Low Comorbidity Burden, Cardiovascular Comorbidities, Inflammatory Conditions and Less Obesity, and Inflammatory Conditions and Obesity.

CONCLUSIONS

Our study demonstrates the power of leveraging the EHR to understand the relative health burden of OSA, as well as heterogeneity in these relationships based on age and sex. In addition to enrichment for comorbidities, we identified 5 novel OSA subtypes defined by combinations of comorbidities in the EHR, which may be informative for understanding disease outcomes and improving prevention and clinical care. Overall, this study adds more evidence that OSA is heterogeneous and requires personalized management.

CITATION

Te TT, Keenan BT, Veatch OJ, Boland MR, Hubbard RA, Pack AI. Identifying clusters of patient comorbidities associated with obstructive sleep apnea using electronic health records. J Clin Sleep Med. 2024;20(4):521-533.

Reaction time in psychomotor vigilance task is related to hypoxic load in males with sleep apnea

Oxygen saturation (SpO2 )-based parameters are more strongly linked to impaired daytime vigilance than the conventional diagnostic metrics in patients with obstructive sleep apnea (OSA). However, whether the association between SpO2 -based parameters and impaired daytime vigilance is modulated by sex, remains unknown. Hence, we investigated the interplay between sex and detailed SpO2 -based metrics and their association with impaired vigilance in patients with OSA. The study population consisted of 855 (473 males, 382 females) patients with suspected OSA who underwent overnight polysomnography and psychomotor vigilance task (PVT). The population was grouped by sex and divided into quartiles (Q1-Q4) based on median reaction times (RTs) in the PVT. In addition to conventional diagnostic metrics, desaturation severity (DesSev), fall severity (FallSev), and recovery severity (RecovSev) were compared between the sexes and between the best (Q1) and worst (Q4) performing quartiles by using cumulative distribution functions (CDFs). Additionally, sex-specific covariate-adjusted linear regression models were used to investigate the connection between the parameters and RTs. The CDFs showed significantly higher hypoxic load in Q4 in males compared to females. In addition, the DesSev (β = 8.05, p < 0.01), FallSev (β = 6.48, p = 0.02), RecovSev (β = 9.13, p < 0.01), and Oxygen Desaturation Index (β = 12.29, p < 0.01) were associated with increased RTs only in males. Conversely, the Arousal Index (β = 10.75-11.04, p < 0.01) was associated with impaired vigilance in females. The severity of intermittent hypoxaemia was strongly associated with longer RTs in males whereas the Arousal Index had the strongest association in females. Thus, the impact of hypoxic load on impaired vigilance seems to be stronger in males than females.

Nocturnal gastro-oesophageal reflux and respiratory symptoms are increased in sleep apnoea: comparison with the general population

AIM

To assess respiratory symptoms and nocturnal gastro-oesophageal reflux (nGER) among untreated obstructive sleep apnoea (OSA) patients, compared with the general population. Also, if nGER associates differently with respiratory symptoms among OSA patients.

METHODS

2 study cohorts were included: 822 newly diagnosed subjects with moderate-severe OSA and 738 Icelandic general population study participants. All participants answered the same questionnaires. Those reporting nGER symptoms at least once per week were defined as 'with nGER'; those without nGER symptoms and without nGER medication were defined as 'no nGER'; and other participants were defined as having 'possible nGER'. Propensity score-based weights were used to minimise confounding and selection bias and facilitate causal interpretations.

RESULTS

The prevalence of nGER among OSA patients was 14.1%, compared with 5.8% in the general population. This increased prevalence in OSA was not explained by differences in age, gender, body mass index, smoking, hypertension and diabetes (adjusted OR (95% CI)=3.79 (2.24 to 6.43)). OSA patients 'with nGER' and with 'possible nGER' reported more wheezing (44% and 44% vs 25%, respectively) and productive cough (47% and 42% vs 29%, respectively), compared with OSA patients with 'no nGER'. The same pattern was seen in the general population, although with a generally lower prevalence. The effect of nGER on respiratory symptoms was similar between the two cohorts.

CONCLUSION

nGER was more often reported among untreated moderate-severe OSA patients than in the general population. Participants with nGER had more wheezing and productive cough, both among untreated OSA patients and in the general population.

Patient-reported experience with hypoglossal nerve stimulation in the treatment of obstructive sleep apnea

BACKGROUND

Breathing-synchronized hypoglossal nerve stimulation (HNS) is routinely used as an alternative treatment for patients with obstructive sleep apnea (OSA). Significant and clinically relevant improvements in disease severity and OSA symptoms such as daytime sleepiness as well as overall quality of life have been reported in randomized-controlled trials and large real-world cohort studies. However, so far, few data exist on patient-reported experience with the treatment.

METHODS

A structured survey with 22 questions was constructed using five-level Likert scales (1 = no agreement, 5 = complete agreement) to evaluate patient experience with HNS and perception of the treatment in the domains "Overall experience with therapy," "Experience with treatment process," and "Side-effects from treatment." Additional data were collected on current symptom status, measured with Epworth sleepiness scale (ESS) questionnaire, and OSA disease history. Multiple linear regression analysis was conducted to test associations of medical variables and response behavior. Correlations between variables and domains, as well as individual items, were assessed using Spearman rank test.

RESULTS

A total of 75 patients from Germany who were treated with breathing-synchronized HNS were enrolled (mean age 57.3 years, 78% male), and 71 questionnaires with complete data were included for analysis. Two-thirds of participants (67%) had a history of OSA history for 5 years or longer. Of all patients, 76% had normalized OSA symptoms at time of the study (ESS: 6.4 ± 5.0) and 98% reported using stimulation therapy every night. Regression analysis revealed an association of current symptoms measured with ESS and response behavior. Hence, patients with normalized daytime sleepiness reported significantly more positive experience across all domains assessed, compared to patients with residual daytime sleepiness. Overall, only 2% of participants reported side effects that made them reduce or discontinue stimulation therapy. The rate of reported side effects was associated with current symptom control under therapy.

CONCLUSIONS

Overall patient-reported experience with breathing-synchronized HNS therapy was positive and high satisfaction with the treatment process was observed. Side effects occurred, but rarely affected subjective use of the therapy or satisfaction. Subjective experience and perception are influenced by residual daytime sleepiness with stimulation therapy.

Relationship of serum 25-hydroxyvitamin D, obesity with new-onset obstructive sleep apnea

OBJECTIVE

The prospective association between vitamin D and obstructive sleep apnea (OSA) remains uncertain. We aimed to assess the association between serum 25-hydroxyvitamin D (25(OH)D), a major circulating form of vitamin D, and new-onset OSA, and examine the modifying effect of obesity.

MATERIALS AND METHODS

This prospective cohort study included 444,975 participants from UK Biobank without prior OSA. The primary outcome was new-onset OSA.

RESULTS

During a median follow-up duration of 12.0 years, 6051 (1.4%) participants occurred new-onset OSA. Overall, there was an inverse relation of serum 25(OH)D concentrations with the risk of new-onset OSA (per SD increment, HR, 0.92; 95%CI: 0.89-0.95). In the analysis of the interactions of serum 25(OH)D with the combination of BMI (<25, 25- < 30, and ≥30 kg/m2) and waist circumference (WC) (<90 and ≥90 cm) categories on new-onset OSA, the significantly inverse association of serum 25(OH)D and new-onset OSA was mainly found in participants with both BMI ≥ 25 kg/m2 and WC ≥ 90 cm (BMI 25-30 kg/m2 and WC ≥ 90 cm: per SD increment, HR, 0.90; 95%CI: 0.84-0.95; BMI ≥ 30 kg/m2 and WC ≥ 90 cm: per SD increment, HR, 0.85; 95%CI: 0.81-0.88), but not in other four groups with BMI < 25 kg/m2 or WC < 90 cm (P -interaction = 0.004).

CONCLUSIONS

There was an inverse relation of serum 25(OH)D with the risk of new-onset OSA in participants with both BMI ≥ 25 kg/m2 and WC ≥ 90 cm. Our findings suggest the importance of maintaining a higher serum 25(OH)D concentration for primary prevention of OSA in a population with obesity.

Age-related differences in the association of mild-to-moderate sleep apnea with incident cardiovascular and cerebrovascular diseases

BACKGROUND

Mild-to-moderate obstructive sleep apnea (mmOSA) is highly prevalent in the general population. However, studies on its association with incident cardiovascular and/or cerebrovascular disease (CBVD) are limited. We examined the association between mild-to-moderate OSA and incident cardiovascular and/or cerebrovascular (CBVD) in a general population sample, and whether age modifies this association.

METHODS

A total of 1173 adults from the Penn State Adult Cohort (20-88 years) without CBVD or severe OSA at baseline were followed-up after 9.2 (±4.1) years. Incident CBVD was defined based on a self-report of a physician diagnosis or treatment for heart disease and/or stroke. Logistic regression examined the association of mild-to-moderate OSA (AHI 5-29.9) with incident CBVD and the combined effect of mmOSA and MetS on incident CBVD after adjusting for multiple confounders.

RESULTS

Age significantly modified the association between mmOSA with incident CBVD (p-interaction = 0.04). Mild-to-moderate OSA was significantly associated with incident CBVD in adults aged <60 years (OR = 1.74, 95%CI = 1.06-2.88, p = 0.029), but not in adults aged ≥60 years (OR = 0.71, 95%CI = 0.39-1.27, p = 0.247). Even mild OSA (AHI 5-14.9) carried a significant risk for incident CBDV in adults aged <60 years (OR = 1.86, 95%CI = 1.05-3.28, p = 0.032). An additive effect was found between mmOSA and MetS with incident CBVD in those aged <65 years (OR = 3.84, 95%CI = 1.95-7.56, p<0.001).

CONCLUSIONS

The risk of incident CBVD is increased in young and middle-aged but not older adults with mmOSA, which may affect the way we currently diagnose and treat this highly prevalent sleep-related breathing disorder.

Obstructive Sleep Apnea Among Patients with Mild Cognitive Impairment

Background

Obstructive sleep apnea (OSA) is associated with cognitive disorders, but little is known about prevalence of co-occurring OSA and mild cognitive impairment (MCI) as well as about co-occurring OSA and Alzheimer's disease (AD). Pathophysiological models integrating OSA, cognitive deficits and neurodegeneration remain speculative. Findings in this area could contribute to the knowledge about pathophysiological processes in cognitive disorders and neurodegenerative processes, be helpful for the diagnosis of cognitive disorders and provide approaches for the treatment of cognitive disorders.

Objective

Examining the prevalence of OSA and patterns of cognitive deficits as well as AD biomarker profiles associated with OSA in a cohort of 104 MCI patients.

Methods

Assessments used include: respiratory polygraphy, The Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD NB), Tau, phosphoTau181, amyloid-β-1-42/1-40, 18F-fluorodeoxyglucose positron emission tomography (F18-FDG-PET).

Results

Prevalence of OSA of any severity: 58,7% (Apnea Hypopnea Index (AHI)≥5/h), OSA in a moderate-to-severe extent (AHI≥15/h): 25%. Only 13.1% of MCI patients with OSA reported daytime sleepiness. MCI-OSA patients showed no specific neuropsychological pattern. Presence of OSA was not associated with specific AD biomarker profiles in the whole study group besides a positive association between AD positivity in an AD biomarker sub cohort.

Conclusions

OSA is highly prevalent in patients with MCI. It might often remain undiagnosed as only a small number of MCI-OSA patients report daytime sleepiness. OSA could contribute to MCI symptoms and even to AD pathology. Further research is needed to validate these findings and to investigate possible pathophysiological relationships between OSA and MCI as well as between OSA and AD.

Long-term health outcomes for patients with obstructive sleep apnea: placing the Agency for Healthcare Research and Quality report in context-a multisociety commentary

This multisociety commentary critically examines the Agency for Healthcare Research and Quality (AHRQ) final report and systematic review on long-term health outcomes in obstructive sleep apnea. The AHRQ report was commissioned by the Centers for Medicare & Medicaid Services and particularly focused on the long-term patient-centered outcomes of continuous positive airway pressure, the variability of sleep-disordered breathing metrics, and the validity of these metrics as surrogate outcomes. This commentary raises concerns regarding the AHRQ report conclusions and their potential implications for policy decisions. A major concern expressed in this commentary is that the AHRQ report inadequately acknowledges the benefits of continuous positive airway pressure for several established, long-term clinically important outcomes including excessive sleepiness, motor vehicle accidents, and blood pressure. While acknowledging the limited evidence for the long-term benefits of continuous positive airway pressure treatment, especially cardiovascular outcomes, as summarized by the AHRQ report, this commentary reviews the limitations of recent randomized controlled trials and nonrandomized controlled studies and the challenges of conducting future randomized controlled trials. A research agenda to address these challenges is proposed including study designs that may include both high quality randomized controlled trials and nonrandomized controlled studies. This commentary concludes by highlighting implications for the safety and quality of life for the millions of people living with obstructive sleep apnea if the AHRQ report alone was used by payers to limit coverage for the treatment of obstructive sleep apnea while not considering the totality of available evidence.

CITATION

Patil SP, Billings ME, Bourjeily G, et al. Long-term health outcomes for patients with obstructive sleep apnea: placing the Agency for Healthcare Research and Quality report in context-a multisociety commentary. J Clin Sleep Med. 2024;20(1):135-149.

The Baveno Classification as a Predictor of CPAP Titration Pressure in Obstructive Sleep Apnea Syndrome

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is a clinical condition characterised by repeated periods of partial or full obstruction of airflow throughout sleep, with impairment of the quality of life and increased mortality with socioeconomic impacts. CPAP therapy is a simple and effective treatment option for OSAS patients. To overcome the clinical and prognostic limitations of AHI-as a sole index of OSAS-the Baveno classification was recently set out and introduced into clinical practice. This study aims to analyse the effect of the Baveno classification on the optimum CPAP titration pressure.

METHODS

A retrospective analysis of the records of sleep studies in two centres between 2018 and 2021 was carried out. Patients diagnosed with OSAS and recruited for CPAP titration were included. Based on the Baveno classification, the patients were categorised into four groups (A, B, C, and D).

RESULTS

Consequently, 700 patients were analysed and 427 patients were included. A significant positive correlation was detected between the CPAP optimum titration pressure and OSAS severity, neck circumference, the oxygen desaturation index (ODI), mean oxygen saturation, the AHI, the BMI, and cumulative sleep time when the SpO2 was <90% (T90) on the other side (p: <0.0001). A non-significant correlation was seen between the Epworth Sleepiness Scale (ESS), symptom severity, end organ impact, and Baveno classification of the CPAP optimum titration pressure (p: 0.8, 0.4, 0.5, and 0.7, respectively).

CONCLUSIONS

The Baveno classification is not useful in the prediction of CPAP optimum titration pressure. However, the ODI and neck circumference were significant independent predictors of a higher CPAP titration pressure.

Causal relationship between levels of myeloperoxidase and obstructive sleep apnea: a bidirectional two-sample Mendelian randomization study

Background

Several observational studies have investigated the association between myeloperoxidase (MPO) and obstructive sleep apnea (OSA). However, the nature of this relationship remains uncertain due to potential selection and confounding biases. To resolve this, we conducted a bidirectional two-sample Mendelian randomization (MR) study to scrutinize the causal relationship between MPO and OSA.

Methods

Instrumental variables (IVs) for OSA were sourced from the publicly available FinnGen dataset, encompassing 38,998 OSA cases and 336,659 controls. Data on MPO were sourced from a study of 21,758 individuals conducted by the European Bioinformatics Institute (EBI). The primary MR analysis utilized the inverse-variance weighted (IVW) method, with MR-Egger intercept and leave-one-out methods assessing pleiotropy and Cochran's Q test determining heterogeneity.

Results

The IVW analysis indicated a causal relationship between heightened MPO levels and an increased incidence of OSA. Individuals with elevated MPO levels manifested a higher propensity to develop OSA, exhibiting an odds ratio (OR) of 1.075 and a 95% confidence interval (CI) of 1.011-1.143 (p = 0.021). Conversely, the reciprocal analysis unveiled no significant association between OSA and heightened MPO levels (p = 0.643). No directional pleiotropy was identified through the MR-Egger intercept test (p > 0.05).

Conclusion

Our study provides evidence of an association between elevated MPO levels and an increased incidence of OSA. However, OSA does not necessarily lead to elevated MPO levels. When patients present with high MPO levels, screening for OSA may be advisable, considering their clinical characteristics.

The economic cost of obstructive sleep apnea: A systematic review

Obstructive sleep apnea (OSA) is a common disease associated with a high prevalence of costly comorbidities and accidents that add to the disease's economic impact. Although more attention has been focused on OSA in recent years, no previous systematic reviews have synthesized findings from existing studies that provide estimates of the economic cost of OSA. This study aims to summarize the findings of existing studies that provide estimates of the cost of OSA. Two bibliographic databases, PubMed and Scopus, were used to identify articles on the costs of OSA. The systematic literature review identified 5,938 publications, of which 31 met the inclusion criteria. According to the results, adjusted for inflation and converted to euros, the annual cost per patient ranged from €236 (the incremental cost of OSA) for New Zealand to €28,267 for the United States. The total annual cost per patient in Europe ranged from €1,669 to €5,186. OSA causes a significant burden on society, and OSA-related costs increase many years before the diagnosis and remain elevated for a long time after the diagnosis. Despite some well-conducted studies, the cost estimates for OSA are uncertain and specific to the context in which the study was conducted.

Association between knowledge and attitudes towards pediatric obstructive sleep apnea and dental specialty

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Longitudinal risk factors for obstructive sleep apnea: A systematic review

Despite substantial disease burden, existing evidence on the risk factors for obstructive sleep apnea (OSA) have been derived primarily from cross-sectional studies without determining temporality. Therefore, we aimed to systematically synthesize the literature on longitudinal risk factors for sleep study-assessed OSA and questionnaire-assessed probable OSA from cohort studies in the general adult population settings. We systematically searched Embase and Medline (on OVID) databases. Eleven studies met the inclusion criteria. Meta-analyses were not conducted due to methodological heterogeneity of exposure and outcome measurements. There was consistent evidence that weight gain was associated with incident (n = 2) and greater severity (n = 2) of OSA. One study each observed an association of higher baseline body-mass index, male sex, asthma, a specific genetic polymorphism in rs12415421, and insulin resistance/hyperglycemia, with incident OSA. Long-term exposure to ambient air pollution (NO2, n = 1) was associated with OSA, and menopausal transitions (n = 1) with higher apnea-hypopnea index. There were no eligible studies on long-term smoking or alcohol use. In conclusion, approximately 10% increase in weight, especially in males, might alert clinicians to consider potential or worsening OSA. Large, well-designed longitudinal studies are needed to consolidate knowledge on other associations with OSA development, especially on potentially modifiable risk factors.

Unmasking Heterogeneity of Sleep Apnea

Sleep apnea is heterogeneous in multiple dimensions. There are different physiological risk factors that may have clinical relevance. However, assessing them is challenging. An approach to ascertain them using a simple model of ventilatory control has been proposed. It is based, however, on untenable assumptions. There are limited validation data and reproducibility is not stellar. There are also different symptom subtypes. They have been found in multiple population-based and clinical cohorts worldwide. Symptomatic benefit from therapy is most marked in the excessively sleepy subtype. This group may also be the group at increased CV risk from obstructive sleep apnea.

Assessment of Leptin Levels and Their Correlation With the Severity of Obstructive Sleep Apnea Syndrome: A Case-Control Study

Background Obstructive sleep apnea (OSA) is characterized by a combination of structural issues in the upper airway and imbalances in the respiratory control system. While numerous studies have linked OSA with obesity, it remains uncertain whether leptin, a hormone associated with fat, plays a role in the functional and anatomical defects that lead to OSA. Therefore, the aim of this study was to investigate whether leptin levels could be used as a predictor of OSA syndrome (OSAS). Methodology A case-control observational study was conducted, enrolling study participants who reported obesity (BMI > 30) within the range of >30 to <35 kg/m2, along with a short neck and a history of snoring, excessive daytime drowsiness, fatigue, or insomnia. Leptin levels and fasting blood sugar (FBS) were measured in all individuals. Additionally, the study evaluated the severity of OSAS using indicators such as the STOP BANG scores, apnea-hypopnea index, uvula grade score, and Epworth Sleepiness Scale scores. Results A total of 80 participants (40 cases and 40 controls) were included in the study. The mean leptin and FBS levels were significantly higher in cases compared to controls. Moreover, leptin levels exhibited a significant correlation with the severity indices of OSAS. Conclusion The study findings indicate that individuals with higher leptin levels tend to exhibit more severe OSAS symptoms. Furthermore, these elevated leptin levels contribute to the worsening of various OSA symptoms. Larger controlled studies have suggested that pharmacologically restoring the altered leptin levels may serve as a beneficial adjunct to treatment for alleviating OSAS symptoms.

Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a common breathing disorder in sleep in which the airways narrow or collapse during sleep, causing obstructive sleep apnea. The prevalence of OSAS continues to rise worldwide, particularly in middle-aged and elderly individuals. The mechanism of upper airway collapse is incompletely understood but is associated with several factors, including obesity, craniofacial changes, altered muscle function in the upper airway, pharyngeal neuropathy, and fluid shifts to the neck. The main characteristics of OSAS are recurrent pauses in respiration, which lead to intermittent hypoxia (IH) and hypercapnia, accompanied by blood oxygen desaturation and arousal during sleep, which sharply increases the risk of several diseases. This paper first briefly describes the epidemiology, incidence, and pathophysiological mechanisms of OSAS. Next, the alterations in relevant signaling pathways induced by IH are systematically reviewed and discussed. For example, IH can induce gut microbiota (GM) dysbiosis, impair the intestinal barrier, and alter intestinal metabolites. These mechanisms ultimately lead to secondary oxidative stress, systemic inflammation, and sympathetic activation. We then summarize the effects of IH on disease pathogenesis, including cardiocerebrovascular disorders, neurological disorders, metabolic diseases, cancer, reproductive disorders, and COVID-19. Finally, different therapeutic strategies for OSAS caused by different causes are proposed. Multidisciplinary approaches and shared decision-making are necessary for the successful treatment of OSAS in the future, but more randomized controlled trials are needed for further evaluation to define what treatments are best for specific OSAS patients.

Behavioral and cognitive outcomes of habitual snoring in children aged 2-14 years in Chengdu, Sichuan

PURPOSE

Habitual snoring is associated with cognitive, behavioral, and other physiological problems of children. Few studies have reported specifically on the relationships between snoring and those problems in children as noticed by their parents. We aimed to identify the cognitive, behavioral, and sleep-related nocturnal problems in children with HS as noted by their parents.

MATERIALS AND METHODS

A cross-sectional survey was performed in Chengdu, Sichuan, China. Children aged 2-14 years from four districts were randomly chosen to participate. Questionnaires were completed voluntarily by the children's parents/guardians.

RESULTS

A total of 1548 questionnaires were analyzed and classified those children as 463 habitual snorers (HS group, 30.4 %), 683 occasional snorers (OS group, 44.8 %), and 402 non-snorers (NS group, 26.4 %). The percentages of children with sleep-related nocturnal symptoms were 94.6 %, 87.3 %, and 66.9 % in the HS, OS, and NS groups. Percentages of children with cognitive problems were 76.2 %, 74.6 %, and 64.9 % in the HS, OS, and NS groups, respectively (P < 0.001). The frequencies of daytime behavioral problems were 68.3 %, 61.5 %, and 46.8%in the HS, OS, and NS groups, respectively (P < 0.001).The average number of sleep-related nocturnal symptoms, cognitive symptoms and daytime behavioral problems was higher in the HS group than in the OS and NS groups.

CONCLUSIONS

HS is a significant contributor to sleep-related nocturnal symptoms and daytime cognitive and behavioral problems in children, as reported by their parents/guardians. HS and OS are important contributors to poor sleep quality and daytime cognitive and behavioral problems in children.

The circadian variation of sleep and alertness of postmenopausal women

STUDY OBJECTIVES

Several factors may contribute to the high prevalence of sleep disturbances occurring in postmenopausal women. However, the contribution of the circadian timing system to their sleep disturbances remains unclear. In the present study, we aim to understand the impact of circadian factors on changes of sleep and alertness occurring after menopause.

METHODS

Eight healthy postmenopausal women and 12 healthy young women in their mid-follicular phase participated in an ultradian sleep-wake cycle procedure (USW). This protocol consisted of alternating 60-min wake periods and nap opportunities for ≥ 48 h in controlled laboratory conditions. Core body temperature (CBT), salivary melatonin, self-reported alertness, and polysomnographically recorded sleep were measured across this procedure.

RESULTS

In both groups, all measures displayed a circadian variation throughout the USW procedure. Compared to young women, postmenopausal women presented lower CBT values, more stage N1 and N2 sleep, and number of arousals. They also showed a reduced amplitude of the circadian variation of melatonin, total sleep time (TST), sleep onset latency (SOL), stage N3 sleep, and alertness levels. Postmenopausal women fell asleep faster and slept more during the biological day and presented higher alertness levels during the biological night than young women.

CONCLUSION

These results support the hypothesis of a weakened circadian signal promoting sleep and wakefulness in older women. Aging processes including hormonal changes may be main contributors to the increased sleep-wake disturbances after menopause.

Carotid Body-Mediated Chemoreflex Function in Aging and the Role of Receptor-Interacting Protein Kinase

Ventilatory impairment during aging has been linked to carotid body (CB) dysfunction. Anatomical/morphological studies evidenced CB degeneration and reductions in the number of CB chemoreceptor cells during aging. The mechanism(s) related to CB degeneration in aging remains elusive. Programmed cell death encompasses both apoptosis and necroptosis. Interestingly, necroptosis can be driven by molecular pathways related to low-grade inflammation, one hallmark of the aging process. Accordingly, we hypothesized that necrotic cell death dependent on receptor-interacting protein kinase-3 (RIPK3) may contribute, at least in part, to impair CB function during aging. Adult (3 months) and aged (24 months) wild type (WT) and RIPK3^-/- mice were used to study chemoreflex function. Aging results in significant reductions in both the hypoxic (HVR) and hypercapnic ventilatory responses (HCVR). Adult RIPK3^-/- mice showed normal HVR and HCVR compared to adult WT mice. Remarkable, aged RIPK3^-/- mice displayed no reductions in HVR nor in HCVR. Indeed, chemoreflex responses obtained in aged RIPK3^-/- KO mice were undistinguishable from the ones obtained in adult WT mice. Lastly, we found high prevalence of breathing disorders during aging and this was absent in aged RIPK3^-/- mice. Together our results support a role for RIPK3-mediated necroptosis in CB dysfunction during aging.

Frequency and evolution of sleep-wake disturbances after ischemic stroke: A 2-year prospective study of 437 patients

OBJECTIVE

In the absence of systematic and longitudinal data, this study prospectively assessed both frequency and evolution of sleep-wake disturbances (SWD) after stroke.

METHODS

In 437 consecutively recruited patients with ischemic stroke or transient ischemic attack (TIA), stroke characteristics and outcome were assessed within the 1^st week and 3.2 ± 0.3 years (M±SD) after the acute event. SWD were assessed by interview and questionnaires at 1 and 3 months as well as 1 and 2 years after the acute event. Sleep disordered breathing (SDB) was assessed by respirography in the acute phase and repeated in one fifth of the participants 3 months and 1 year later.

RESULTS

Patients (63.8% male, 87% ischemic stroke and mean age 65.1 ± 13.0 years) presented with mean NIHSS-score of 3.5 ± 4.5 at admission. In the acute phase, respiratory event index was >15/h in 34% and >30/h in 15% of patients. Over the entire observation period, the frequencies of excessive daytime sleepiness (EDS), fatigue and insomnia varied between 10-14%, 22-28% and 20-28%, respectively. Mean insomnia and EDS scores decreased from acute to chronic stroke, whereas restless legs syndrome (RLS) percentages (6-9%) and mean fatigue scores remained similar. Mean self-reported sleep duration was enhanced at acute stroke (month 1: 07:54 ± 01:27h) and decreased at chronic stage (year 2: 07:43 ± 01:20h).

CONCLUSIONS

This study documents a high frequency of SDB, insomnia, fatigue and a prolonged sleep duration after stroke/TIA, which can persist for years. Considering the negative effects of SWD on physical, brain and mental health these data suggest the need for a systematic assessment and management of post-stroke SWD.

Validity of a New Prediction Model to Identify Patients at Risk for Obstructive Sleep Apnea Hypopnea Syndrome

OBJECTIVES

To develop and validate a new clinical prediction model for screening patients at risk for obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

This study used 2 data sets to develop and validate the model. To build the model, the first data set comprised 892 patients who had diagnostic polysomnography (PSG); data were assessed by multivariate logistic regression analysis. To validate the new model, the second data set comprised 374 patients who were enrolled to undergo overnight PSG. Receiver operating characteristic analysis and all predictive parameters were validated.

RESULTS

In the model development phase, univariate analysis showed 6 parameters were significant for prediction apnea-hypopnea index ≥15 events/hour: male sex, choking or apnea, high blood pressure, neck circumference >16 inches (female) or 17 inches (male), waist circumference ≥80 (female) or 90 cm (male), and body mass index >25 kg/m². Estimated coefficients showed an area under the curve of 0.753. In the model validation phase, the sensitivity and specificity were approximately 93% and 26%, respectively, for identifying OSAHS. Comparison with the Epworth Sleepiness Scale score of ≥10 and STOP-Bang score ≥3 showed sensitivity of 42.26% and 56.23%, respectively, for detecting patients at risk.

CONCLUSIONS

This new prediction model gives a better result on identifying patients at risk for OSAHS than Epworth Sleepiness Scale and STOP-Bang in terms of sensitivity. Moreover, this model may play a role in clinical decision-making for a comprehensive sleep evaluation to prioritize patients for PSG.

Desaturation event scoring criteria affect the perceived severity of nocturnal hypoxic load

OBJECTIVES/BACKGROUND

Interest in using blood oxygen desaturations in the diagnostics of sleep apnea has risen in recent years. However, no standardized criteria for desaturation scoring exist which complicates the drawing of solid conclusions from literature.

PATIENTS/METHODS

We investigated how different desaturation scoring criteria affect the severity of nocturnal hypoxic load and the prediction of impaired daytime vigilance in 845 patients. Desaturations were scored based on three features: 1) minimum oxygen saturation drop during the event (2-20%, 1% interval), 2) minimum duration of the event (2-20s, 1s interval), and 3) maximum plateau duration within the event (5-60s, 5s interval), resulting in 4332 different scoring criteria. The hypoxic load was described with oxygen desaturation index (ODI), desaturation severity (DesSev), and desaturation duration (DesDur) parameters. Association between hypoxic load and impaired vigilance was investigated with covariate-adjusted area under curve (AUC) analyses by dividing patients into normal (≤5 lapses) and impaired (≥36 lapses) vigilance groups based on psychomotor vigilance task performance.

RESULTS

The severity of hypoxic load varied greatly between different scoring criteria. For example, median ODI ranged between 0.4 and 12.9 events/h, DesSev 0.01-0.23 %-point, and DesDur 0.3-9.6 %-point when the minimum transient drop criterion of 3% was used and other two features were altered. Overall, the minimum transient drop criterion had the largest effect on parameter values. All models with differently determined parameters predicted impaired vigilance moderately (AUC = 0.722-0.734).

CONCLUSIONS

Desaturation scoring criteria greatly affected the severity of hypoxic load. However, the difference in the prediction of impaired vigilance between different criteria was rather small.

Cancer Risk Associated with Continuous Positive Airway Pressure: A National Study

OBJECTIVE

In 2021 the U.S. FDA issued a Class 1 safety recall notice for specific devices due to a risk of carcinogen exposure. The objective of this study was to evaluate reports of cancer linked to CPAP devices to understand implications for the field of sleep medicine.

METHODS

Cases of cancer involving CPAP devices were retrieved from the MAUDE database from 2014 to 2021 and analyzed with descriptive statistics.

RESULTS

A total of 2571 patient injuries were associated with CPAP. Reports of cancer (n = 209; 4.62%) were the second most commonly documented patient problem associated with CPAP, although 1950 (43.13%) patients had a device problem without an associated injury. Of the 209 cancer cases associated with CPAP, 200 (95.7%) of the adverse event reports were received by the FDA in 2021. There were 174 (9.15%) descriptions of the CPAP polyurethane sound abatement foam degrading in association with a cancer diagnosis, but degradation was more commonly not associated with malignancy (n = 1728; 90.85%). Other frequently documented CPAP device problems included broken devices (n = 279; 6.92%), fire (n = 182; 4.51%), and patient-device incompatibility (n = 144; 3.57%).

CONCLUSION

Malignancy associated with CPAP devices has been reported; however, future studies are required to establish causation. Given 95.7% of those documented cases were reported in 2021, otolaryngologists should be prepared to discuss the risks of carcinogenesis associated with CPAP. The otolaryngology community should also be aware of the potential bandwagon effect and the implications for CPAP compliance.

LEVEL OF EVIDENCE

4 Laryngoscope, 132:2270-2274, 2022.

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

STUDY OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CITATION

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

Examining the impact of excessive daytime sleepiness on utility scores in patients with obstructive sleep apnoea and/or narcolepsy in five European countries

BACKGROUND

Excessive daytime sleepiness (EDS) is a cardinal symptom of narcolepsy and affects many patients with obstructive sleep apnoea (OSA). EDS is associated with reduced quality of life, increased accident risk, and poor workplace performance. Given the impact of EDS, the ability to predict health-related utility from sleepiness is valuable for examining the cost effectiveness of novel treatments. The aim of this study was to examine the association between EDS and EQ-5D in patients with OSA and/or narcolepsy by modelling EQ-5D utility scores from Epworth Sleepiness Scale (ESS) scores.

METHODS

Data were obtained from the Europe 2016/2017 National Health and Wellness Survey, an online, general population survey, designed to represent the age and gender composition of each country's adult population. Analyses included 2,348 patients self-reporting symptomatic and diagnosed OSA (n = 2,277), narcolepsy (n = 48), or both (n = 23). Multivariable models were used to examine ESS as a predictor of EQ-5D utility while adjusting for covariates of interest. Results were validated following the National Institute for Health and Care Excellence Decision Support Unit guidelines for predictive modelling.

RESULTS

Utility decreased as EDS severity increased (no EDS: 0.711 ± 0.251, mild: 0.685 ± 0.261, moderate: 0.643 ± 0.268, severe: 0.559 ± 0.323). Whereas participants with only OSA or only narcolepsy did not differ in utility, those with both conditions had lower scores (0.685 ± 0.266 and 0.627 ± 0.325 vs. 0.439 ± 0.340, respectively). Piecewise linear regression identified a single breakpoint at ESS score of 11.29. In the final model, for each point increase in ESS score, the corresponding decrease in EQ-5D utility was larger among patients with ESS scores ≥ 12 compared to patients with ESS scores ≤ 11 (model slopes: -0.0131 vs. -0.0026, respectively). Findings from the validation sample confirmed these results.

CONCLUSIONS

This study demonstrates the impact of sleepiness on quality of life (QoL) and its negative impact irrespective of sleep condition (OSA or narcolepsy). The breakpoint identified is relatively consistent with the established ESS cutoff score ≥ 11, which demarcates pathological sleepiness. Furthermore, as EDS severity worsens (increases) on the ESS, the impact on QoL is greater.

Association between early stage N2 sleep spindle burst characteristics and vigilance groups: an observational study on patients from a tertiary sleep centre

OBJECTIVE

Obstructive Sleep Apnoea (OSA) is associated with impaired vigilance. This paper examines the hypothesis that sleep spindle (Sp) characteristics during nocturnal sleep can be mapped to vigilance deficits measured by the Psychomotor Vigilance Task (PVT) in patients with OSA.

APPROACH

The PVT was performed prior to In-laboratory Polysomnography for 250 patients. PVT outcomes were clustered into three Vigilance Groups (VGs). Spindles were scored manually for a Training Cohort of 55 patients, (9491 Sps) across different blocks of NREM sleep (SBs) and validated in a Test Cohort (25 patients, 4867 Sps). We proposed a novel set of Sp features including a Spindle Burst Index (SBI), which quantifies the burst characteristics of spindles and constructed models mapping them to VGs. We also explored the performance of conventional Sp features (such as Sp number and density) in our modelling approach.

MAIN RESULTS

In the Training Cohort, we observed statistically significant differences in the SBI across VGs and SBs independent of OSA severity (1st Stage N2 SBI; p=<0.001 across VGs). In the Test Cohort, a Model based on the proposed SBI predicted VG membership with 88% accuracy. A model based on conventional Sp features mapped to VGs with 70.7% accuracy, and a model using mixed burst and conventional features reached an accuracy of 88%.

SIGNIFICANCE

Spindle features measured during diagnostic In-laboratory PSG can be mapped to PVT outcomes. The novel SBI proved useful for exploring the relationship between PVT outcomes and sleep. Further studies in larger populations are needed to verify these conclusions.

Current and Novel Treatment Options for OSA

Obstructive sleep apnoea is a challenging medical problem due to its prevalence, its impact on quality of life and performance in school and professionally, the implications for risk of accidents, and comorbidities and mortality. Current research has carved out a broad spectrum of clinical phenotypes and defined major pathophysiological components. These findings point to the concept of personalised therapy, oriented on both the distinct clinical presentation and the most relevant pathophysiology in the individual patient. This leads to questions of whether sufficient therapeutic options other than positive airway pressure (PAP) alone are available, for which patients they may be useful, if there are specific indications for single or combined treatment, and whether there is solid scientific evidence for recommendations. This review describes our knowledge on PAP and non-PAP therapies to address upper airway collapsibility, muscle responsiveness, arousability and respiratory drive. The spectrum is broad and heterogeneous, including technical and pharmaceutical options already in clinical use or at an advanced experimental stage. Although there is an obvious need for more research on single or combined therapies, the available data demonstrate the variety of effective options, which should replace the unidirectional focus on PAP therapy.

The analysis of individual pathophysiological composition opens new directions towards personalised treatment of OSA, focusing not only on pharyngeal dilation, but also on technical or pharmaceutical interventions on muscle function or breathing regulationhttps://bit.ly/3sayhkd

Berlin and Epworth Surveys to Predict Obstructive Sleep Apnea for Adults on Biomimetic Oral Appliance Therapy: A Nonrandomized Clinical Trial

Background

Two questionnaires (Berlin Questionnaire (BQ) and Epworth Sleepiness Scale (ESS)) are the widely used screening instruments for subjects suffering from sleep disorders. Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing. The biomimetic oral appliance therapy (BOAT) offers an alternative nonsurgical method, which can improve symptoms and indices of OSA on objective sleep testing.

Aim

To describe testing the ability of BQ and EES for prediction of BOAT outcomes during OSA.

Methods

Seventeen adults (9 males, 8 females; age, mean (SD): 45.76 (10.31), BMI mean (SD): 33.5(13.43)) who underwent an overnight sleep study were diagnosed by a sleep specialist physician. The BQ and EES were recorded before and after BOAT treatment. Subjects with mild-to-moderate OSA had 2 months of follow-up visits and underwent a final overnight sleep study to measure apnea-hypopnea index (AHI). The subjects were asked to wear the appliance for 10–12 hours/day and at night. Findings were analyzed statistically using paired t-tests.

Result

As per sleep test results, pre-BOAT AHI measures versus post-BOAT AHI measures showed significant improvement. Comparing the BQ before versus after treatment showed that at the pretreatment stage, 66.0% of patients had high-risk score, whereas 34% had low-risk score. After treatment, 66.0% of patient had low-risk scores, whereas 34% had high-risk scores. As for the ESS, treatment resulted in significant reduction of total score from 10.43 ± 6.32 to 5.00 ± 5.20 (P < 0.01, paired t-test). Finally, there was a mild negative correlation between AHI and each of the BQ and ESS scores that was not statistically significant (r = −0.420, N = 26, P > 0.05, and r = −0.41, N = 26, P > 0.05, respectively).

Conclusion

The BOAT device may provide a useful form of therapy to improve OSA-related PSG parameters such as AHI. Both BQ and ESS were predictive to improvements detected by the sleep study during BOAT device use.

Effect of modified genioglosuss advancement on hyoid bone position: Cephalometric study

OBJECTIVE

To assess Hyoid bone position and retrolingual airway space after Modified Genioglossus Advancement Surgery by cephalometry in patients with obstructive sleep apnea (OSA).

STUDY DESIGN

Prospective study.

SETTING

Zagazig University Hospital.

METHODS

Eighteen patients with moderate to severe OSA having multilevel airway obstruction confirmed by fiberoptic endoscopy during Muller's maneuver and DISE. All patients underwent modified genioglossus advancement surgery associated with antrolateral advancement pharyngoplasty. Beside Polysomnography and Drug induced sleep endoscopy, Cephalometry was done preoperatively and 6 months postoperative.

RESULTS

Improved Polysomnography parameters as Postoperative mean ± SD apnea hypopnea index decreased from 52 ± 17.1 to 17 ± 3 (P < 0.001, 95% confidence interval 27.71 to 42.41). LOS increased from 79.89 ± 4.43% to 83 ± 4.05% (P 0.07, 95% confidence interval -0.31 to 6.97). Cephalometry analysis showed a significant difference between preoperative and postoperative findings, including: Retrolingual airway space at three levels significantly increased; Level 1 from 6.1 ± 1.6 to 8.5 ± 1.7, Level 2 from 10.5 ± 2.4 to 13.9 ± 2.1, Level 3 from 15.7 ± 3.1 to 21 ± 4, H-GN decreased from 51 ± 7 to 39 ± 8, H-MP decreased from 31.6 ± 7.7 to 24.9 ± 7.3, HS decreased from 121 ± 15 to 102 ± 12, H-PH increased from 29 ± 8 to 43 ± 9. With a success rate defined as AHI <20 and a 50% decrease in AHI of the preoperative value, the surgical success rate was 83.33%.

CONCLUSION

This study showed that Modified genioglossus advancement procedures done for OSA patients significantly changed the position of hyoid bone into a more anterior and superior position and this was reflected in the postoperative Polysomnography.

Higher HEI-2015 Scores Are Associated with Lower Risk of Sleep Disorder: Results from a Nationally Representative Survey of United States Adults

Whether there is an association between dietary quality and sleep disorder in American adults is unclear. We conducted this study to analyze whether dietary quality, using the Healthy Eating Index-2015 (HEI-2015) scores as the measure, was associated with self-reported sleep disorders. Data came from the National Health and Nutrition Examination Survey (2005–2014). Step-weighted logistic regression models were performed to explore the relationships between the HEI-2015 scores and sleep disorder. Weighted quantile sum regression model was used to identify the HEI-2015 components most strongly associated with sleep disorders. According to quartiles, HEI scores were categorized into inadequate (<25%), average (25–75%), and optimal (>75%). Compared to inadequate HEI status, average HEI status (OR: 0.961, 95%CI: 0.959–0.962) and optimal HEI status (OR: 0.913, 95% CI: 0.912–0.915) were associated with reduced risk of sleep disorder after multivariable adjustments. Greens and beans, added sugars, saturated fats, total vegetables and total protein foods were the top five important components for sleep disorders. Our results suggest that there is a statistically significant association between better dietary quality and reduced risk of sleep disorder among United States adults.

Silencing MR-1 Protects against Myocardial Injury Induced by Chronic Intermittent Hypoxia by Targeting Nrf2 through Antioxidant Stress and Anti-Inflammation Pathways

BACKGROUND

Patients with obstructive sleep apnea hypopnea syndrome (OSAHS) often have cardiac insufficiency mainly due to hypoxia/reperfusion injury caused by chronic intermittent hypoxia (CIH). Inflammation and oxidative stress are involved in the cardiovascular events of OSAHS patients. Studies have found that myofibrillation regulator-1 (MR-1) participates in the pathological process of OSAHS-induced myocardial injury, but the specific mechanism is still unclear.

METHODS

We used a CIH-induced rat model to simulate the process of OSAHS disease. Indices of myocardial injury, inflammation, and oxidative stress were detected using quantitative PCR and enzyme-linked immunosorbent assay (ELISA). After administration of adenoassociated viral vector (AAV) encoding silencing RNA against MR-1, we examined expression of the classic antioxidant stress pathway protein NF-E2-related factor 2 (Nrf2) using western blotting.

RESULTS

We found that levels of serum inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 were increased, and we further observed disturbance of the oxidative stress system, in which the content of reactive oxygen species (ROS), superoxide dismutase (SOD), reduced glutathione (GSH), and malondialdehyde (MDA) was enhanced in CIH-induced rats. Subsequently, we detected that expression of Nrf2 and heme oxygenase-1 (HO-1) was slightly increased, while the expression of Kelch-like ECH-associated protein 1 (Keap-1) was significantly increased in the CIH model. Interestingly, after administration of silencing MR-1 AAV, the elevated levels of inflammatory factors were reduced, and the disordered oxidative stress system was corrected. Additionally, the expression of Nrf2 and HO-1 was distinctly increased, but the high expression of Keap-1 was decreased.

CONCLUSIONS

Our research results demonstrate that silencing MR-1 rescued the myocardium the injury from inflammatory and oxidative stress in CIH-induced rats by administration of the Nrf2 signaling pathway.

Effect of Obstructive Sleep Apnea on the Risk of Injuries-A Nationwide Population-Based Cohort Study

Obstructive sleep apnea (OSA) has been reported to increase the risk of motor vehicle accidents. However, only few studies have investigated the effects of OSA on overall risk injury. The aim of study is to investigate whether OSA increases the risk of overall injury. The data were collected during 2000–2015 from Taiwan’s National Health Insurance Research Database. A total of 8901 individuals diagnosed with OSA were inpatients, or outpatients at least three times were enrolled. Finally, 6915 participants with OSA were included as the study cohort. We matched the study cohort with a comparison cohort, at a ratio of 1:4. Cox proportional hazards regression was used to analyse the association between OSA and overall injury. Patients with OSA had 83.1% increased risk of overall injury, compared to non-OSA individuals [adjusted hazards ratio (HR) = 1.831, confidence interval (CI) = 1.674–2.020, p < 0.001]. In the stratified age group, patients aged ≧65 years had the highest risk of injury (adjusted HR= 2.014; CI = 1.842–2.222, p < 0.001). Patients with OSA were at a higher risk of falls, traffic injury, poisoning, suffocation, suicide, and abuse or homicide than non-OSA individuals, with falls and traffic injury as the leading causes of injuries. The data demonstrated that patients with OSA have a higher risk of overall injury. The study results can be a reference for developing injury prevention strategies in the future. The general population and clinicians should have more awareness regarding OSA and its negative effects on injury development.

Phenotypes of obstructive sleep apnea in the Hispanic Community Health Study/Study of Latinos

STUDY OBJECTIVES

Recent work on US Whites from clinical samples used obstructive sleep apnea (OSA) symptoms to generate phenotypes for individuals with moderate-severe OSA which suggested 3 to 5 symptom classes. However, it is unknown whether similar classes generalize to diverse Hispanics/Latino adults. Therefore, we sought to fill this gap by empirically deriving sleep phenotypes among a large sample of diverse Hispanics/Latinos.

METHODS

We used data from The Hispanic Community Health Study/Study of Latinos (HCHS/SOL; 2008-2011), a prospective cohort study designed using a multisite multistage probability sample of adults 18-74 years old. The subpopulation of interest included participants with moderate-severe OSA symptoms (≥15 respiratory event index (REI) events per hour; n = 1,605). We performed latent class analysis for complex survey data using 15 common OSA symptoms (e.g. Epworth Sleepiness Scale) and 4 comorbidities to identify phenotype classes.

RESULTS

Average age was 52.4 ± 13.9 years and 34.0% were female. Mean REI was 33.8 ± 22.5 events per hour. Fit statistics and clinical significance suggested that a three-class solution provided the best fit to the data. The three phenotypes were: (1) Minimally Symptomatic (47.7%), (2) Excessive sleepiness (37.1%), and (3) Disturbed Sleep (15.2%). Sensitivity models were consistent with the main proposed solution.

CONCLUSIONS

Derived sleep phenotypes among diverse Hispanic/Latinos were consistent with recent findings from the Sleep Apnea Global Interdisciplinary Consortium, but we found notable differences in class prevalence relative to Whites. Further research is needed to link derived sleep phenotypes to health comorbidities in diverse populations.

Different components of excessive daytime sleepiness and the change with positive airway pressure treatment in patients with obstructive sleep apnea: Results from the Icelandic Sleep Apnea Cohort (ISAC)

Excessive daytime sleepiness includes both an inability to stay awake during the day and a general feeling of sleepiness. We describe different dimensions of daytime sleepiness in adults with moderate-severe obstructive sleep apnea (OSA) before and after 2 years of positive airway pressure (PAP) treatment. Using the Epworth Sleepiness Scale (score >10 defined as "risk of dozing") and Basic Nordic Sleep Questionnaire (feeling sleepy ≥3 times/week defined as "feeling sleepy"), participants were categorised into sleepiness phenotypes labelled non-sleepy, risk of dozing only, feeling sleepy only, or both symptoms. Participants repeated baseline assessments and PAP adherence was evaluated after 2 years. PAP-adherent subjects with sleepiness symptoms at both baseline and follow-up were considered persistently sleepy. Of the 810 participants, 722 (89%) returned for follow-up. At baseline, 17.7% were non-sleepy, 7.7% were at risk of dozing only, 24.7% were feeling sleepy only, and 49.9% had both symptoms. PAP adherence did not differ by baseline sleepiness phenotype. Patients with risk of dozing demonstrated greater PAP benefits for sleepiness symptoms than non-sleepy and feeling sleepy only phenotypes. Using these phenotypes, 42.3% of PAP users had persistent sleepiness; they had less severe OSA (p < 0.001), more persistent OSA symptoms and more often had symptoms of insomnia than patients in whom sleepiness resolved. Our present results, therefore, suggest that measuring the risk of dozing and the feeling of sleepiness reflect different sleepiness components and may respond differently to PAP. Patients feeling sleepy without risk of dozing may need more thorough evaluation for factors contributing to sleepiness before initiating treatment.