Sleep quality, short-term and long-term CPAP adherence

The Beginning of the AI-Enabled Preventative PAP Therapy Era: A First-in-Human Proof of Concept Interventional Study

Positive Airway Pressure (PAP) therapy is the most common and efficacious treatment for Obstructive Sleep Apnea (OSA). However, it suffers from poor patient adherence due to discomfort and may not fully alleviate all adverse consequences of OSA. Identifying abnormal respiratory events before they have occurred may allow for improved management of PAP levels, leading to improved adherence and better patient outcomes. Our previous work has resulted in the successful development of a Machine-Learning (ML) algorithm for the prediction of future apneic events using existing airflow and air pressure sensors available internally to PAP devices. Although researchers have studied the use of ML for the prediction of apneas, research to date has focused primarily on using external polysomnography sensors that add to patient discomfort and has not investigated the use of internal-to-PAP sensors such as air pressure and airflow to predict and prevent respiratory events. We hypothesized that by using our predictive software, OSA events could be proactively prevented while maintaining patients' sleep quality. An intervention protocol was developed and applied to all patients to prevent OSA events. Although the protocol's cool-down period limited the number of prevention attempts, analysis of 11 participants revealed that our system improved many sleep parameters, which included a statistically significant 31.6% reduction in Apnea-Hypopnea Index, while maintaining sleep quality. Most importantly, our findings indicate the feasibility of unobtrusive identification and unique prevention of each respiratory event as well as paving the path to future truly personalized PAP therapy by further training of ML models on individual patients.

Improvement of sleep parameters by titration polysomnography could predict adherence to positive airway pressure therapy in obstructive sleep apnea

STUDY OBJECTIVES

Poor adherence to continuous positive airway pressure (CPAP) has been a critical issue in treating obstructive sleep apnea. Because long-term CPAP adherence may be established shortly after treatment begins, early intervention is essential. This study aimed to identify the potential factors affecting CPAP therapy adherence during diagnostic polysomnography and auto CPAP titration polysomnography.

METHODS

This retrospective observational study included 463 patients with obstructive sleep apnea who underwent consecutive diagnostic polysomnography and titration polysomnography. We recorded their demographic, anthropometric, and lifestyle factors and obtained self-reported comments regarding their sleep status following both polysomnography evaluations. CPAP adherence was evaluated following 3 months of treatment.

RESULTS

A total of 312 patients (67.4%) fulfilled the criteria for good adherence. Each patient's CPAP adherence was categorized as "poor" (< 4 hours/night or <70% of nights), "good" (≥ 4 hours/night and ≥ 70% of nights), or "excellent" (≥ 6 hours/night and ≥ 80% of nights). There were no significant differences in arterial oxyhemoglobin saturation measured by pulse oximetry and apnea-hypopnea index during diagnostic polysomnography among 3 groups. The polysomnographic evaluations indicated that patients with better adherence displayed more significant improvements in sleep parameters, including apnea-hypopnea index, sleep efficacy, sleep latency, and sleep architecture, which were correlated with an improvement in self-reported sleep quality.

CONCLUSIONS

Polysomnographic evaluations enabled CPAP adherence prediction and a comparison of self-reported sleep quality with and without CPAP; CPAP adherence led to improvements in polysomnographic parameters. Our findings suggest that titration polysomnography and self-reported sleep improvement with CPAP could be used for adherence prediction in clinical practice.

CITATION

Shirahata T, Uchida Y, Uchida T, et al. Improvement of sleep parameters by titration polysomnography could predict adherence to positive airway pressure therapy in obstructive sleep apnea. J Clin Sleep Med. 2023;19(8):1465-1473.

Identifying longitudinal patterns of CPAP treatment in OSA using growth mixture modeling: Disease characteristics and psychological determinants

In this study, we aim to identify the distinct subtypes of continuous positive airway pressure (CPAP) user profiles based on the telemedicine management platform and to determine clinical and psychological predictors of various patterns of adherence. A total of 301 patients used auto-CPAP (Autoset 10, Resmed Inc.) during the treatment period. Four categories of potential predictors for CPAP adherence were examined: (1) demographic and clinical characteristics, (2) disease severity and comorbidities, (3) sleep-related health issues, and (4) psychological evaluation. Then, growth mixture modeling was conducted using Mplus 8.0 to identify the unique trajectories of adherence over time. Adherence data were collected from the telemedicine management platform (Airview, Resmed Inc.) during the treatment. Three novel subgroups were identified and labeled “adherers” (53.8% of samples, intercept = 385, slope = −51, high mean value, negative slope and moderate decline), “Improvers” (18.6%, intercept = 256, slope = 50, moderate mean value, positive slope and moderate growth) and “non-adherers” (27.6%, intercept = 176, slope = −31, low mean value, negative slope and slight decline). The comorbidities associated with OSA and the apnea–hypopnea index (AHI), which reflects the objective severity of the disease, did not differ significantly among the subgroups. However, “improvers” showed higher levels of daytime sleepiness (8.1 ± 6.0 vs. 12.1 ± 7.0 vs. 8.0 ± 6.1 in SWIFT, p = 0.01), reduced daytime function (4.6 ± 1.6 vs. 3.8 ± 1.6 vs. 4.2 ± 1.8 in QSQ daytime symptoms, p = 0.02), and characteristics of positive coping style (1.8 ± 0.5 vs. 1.9 ± 0.5 vs. 1.7 ± 0.5 in SCSQ positive coping index, p = 0.02). Negative emotion was more pronounced in patients with “non-adherers” (12.9 ± 3.8 vs. 13.7 ± 3.3 vs. 14.6 ± 3.5, p = 0.02 in the HADS depression dimension; 9.0 ± 6.1 vs. 9.8 ± 5.1 vs. 11.5 ± 6.3, p = 0.01 with Negative Affectivity in DS14, and 9.3 ± 6.1 vs. 10.3 ± 5.1 vs. 11.7 ± 6.5, p = 0.01 with Social Inhibition in DS14). Overall, our study demonstrated that CPAP therapy may present distinct trajectories of adherence over time in addition to the traditional binary classification. Self-reported sleep health issues (diurnal sleepiness and daytime dysfunction) as well as psychological characteristics (negative emotions and coping style) were predictors of different adherence subtypes in patients with OSA. Understanding CPAP use profiles and their predictors enable the identification of those who may require additional intervention to improve adherence and further enhance the therapeutic effect in OSA patients.

Quality measures for the care of adult patients with obstructive sleep apnea: 2022 update after measure maintenance

Obstructive sleep apnea (OSA) remains a highly prevalent disorder that can lead to multiple adverse outcomes when undiagnosed and/or when left untreated. There continue to be gaps and variations in the provision of care for the adult patient population with OSA, which emphasizes the importance of the measure maintenance initiative for The Quality Measures for the Care of Adult Patients with Obstructive Sleep Apnea (originally developed in 2015). The American Academy of Sleep Medicine (AASM) convened the Quality Measures Task Force in 2018 to review the current medical literature, other existing quality measures focused on the same patient population, and any performance data or data in the medical literature that show gaps or variations in care, to inform potential revisions to the quality measure set. These revised quality measures will be implemented in the AASM Sleep Clinical Data Registry (Sleep CDR) to capture performance data and encourage continuous improvement in outcomes associated with diagnosing and managing OSA in the adult population.

CITATION

Lloyd R, Morgenthaler TI, Donald R, et al. Quality measures for the care of adult patients with obstructive sleep apnea: 2022 update after measure maintenance. J Clin Sleep Med. 2022;18(11):2673-2680.

Does race-ethnicity affect upper airway stimulation adherence and treatment outcome of obstructive sleep apnea?

STUDY OBJECTIVES

Untreated obstructive sleep apnea (OSA) is associated with excessive daytime sleepiness, decreased quality of life, and cardiovascular disease. Positive airway pressure is the first-line therapy for OSA; however, adherence is difficult. Upper airway stimulation is a Food and Drug Administration-approved treatment of OSA. The objective of this study was to evaluate for a difference in treatment efficacy and adherence of upper airway stimulation therapy for OSA between individuals who are White and non-White using data from the ADHERE registry.

METHODS

ADHERE registry is a multicenter prospective study of real-world experience of upper airway stimulation for treatment of OSA in the United States and Europe. Propensity score matching was used to create a balanced dataset between the White and non-White groups. t-Tests at a significance level of 5% were used to compare numeric values between groups.

RESULTS

There were 2,755 participants of the ADHERE registry: 27 were excluded due to not having a race identified, 125 participants identified as non-White, 2,603 identify as White, and 27 did not provide race information. Propensity score matching was used to select 110 participants, with 55 White and 55 non-White for the noninferiority analysis. We did not find a difference in adherence, treatment apnea-hypopnea index, changes in Epworth Sleepiness Scale score, or clinical global impression after intervention score between White and non-White individuals.

CONCLUSIONS

Our study found that there was no statistically significant difference in adherence or efficacy with upper airway stimulation therapy between White and non-White individuals. However, the percent of non-White people implanted is low, which suggests a need to expand access to this therapy for non-White populations with OSA who cannot tolerate positive airway pressure therapy.

CITATION

Khan M, Stone A, Soose RJ, et al. Does race-ethnicity affect upper airway stimulation adherence and treatment outcome of obstructive sleep apnea? J Clin Sleep Med. 2022;18(9):2167-2172.

Adherence Index: sleep depth and nocturnal hypoventilation predict long-term adherence with positive airway pressure therapy in severe obstructive sleep apnea

STUDY OBJECTIVES

Treatment of obstructive sleep apnea with positive airway pressure (PAP) devices is limited by poor long-term adherence. Early identification of individual patients' probability of long-term PAP adherence would help in their management. We determined whether conventional polysomnogram (PSG) scoring and measures of sleep depth based on the odds ratio product would predict adherence with PAP therapy 12 months after it was started.

METHODS

Patients with obstructive sleep apnea referred to an academic sleep center had split-night PSG, arterial blood gases, and a sleep questionnaire. Multiple linear regression analysis of conventional PSG scoring and the odds ratio product both during diagnostic PSG and PAP titration provided an "Adherence Index," which was correlated with PAP use 12 months later.

RESULTS

Patients with obstructive sleep apnea (n = 236, apnea-hypopnea index 72.2 ± 34.1 events/h) were prescribed PAP therapy (82% received continuous PAP, 18% received bilevel PAP). Each patient's adherence with PAP therapy 12 months later was categorized as "never used," "quit using," "poor adherence," and "good adherence." PSG measures that were most strongly correlated with PAP adherence were apnea-hypopnea index and odds ratio product during nonrapid eye movement sleep; the additional contribution of nocturnal hypoxemia to this correlation was confined to those with chronic hypoventilation treated with bilevel PAP. The Adherence Index derived from these measures, during both diagnostic PSG and PAP titration, was strongly correlated with PAP adherence 12 months later.

CONCLUSIONS

Long-term adherence with PAP therapy can be predicted from diagnostic PSG in patients with severe obstructive sleep apnea, which may facilitate a precision-based approach to PAP management.

CITATION

Younes MK, Beaudin AE, Raneri JK, Gerardy BJ, Hanly PJ. Adherence Index: sleep depth and nocturnal hypoventilation predict long-term adherence with positive airway pressure therapy in severe obstructive sleep apnea. J Clin Sleep Med. 2022:18(8):1933-1944.

Low arousal threshold is associated with unfavorable shift of PAP compliance over time in patients with OSA

PURPOSE

To determine the predictive factors of initial and long-term adherence to positive airway pressure (PAP) therapy and factors leading to an unfavorable shift of PAP compliance.

METHODS

This follow-up study was comprised of newly diagnosed patients with obstructive sleep apnea (OSA) amenable to PAP therapy from January 2017 to April 2019. Information on basic demographics, comorbidities, and sleep-related symptoms were collected. PAP adherence data were collected at the end of the first week and the third month.

RESULTS

Of 166 patients enrolled, data from 142 (86%) were in the final analysis. Overall PAP usage was worse at 3 months declining from the first week. After adjusting for age and gender, multinomial logistic regression analysis showed that a small number of sleep-related symptoms (OR, 0.69; 95% CI, 0.52-0.91) and low arousal threshold (ArTH) (OR, 4.44; 95% CI, 1.52-12.98) were associated with higher odds of noncompliance. Low ArTH (OR, 2.87; 95% CI, 1.09-7.57) and lower body mass index (BMI) (OR, 0.88; 95% CI, 0.78-0.99) increased the risk of compliance-to-noncompliance shift. Sixty-two patients with polysomnography were analyzed separately. After adjustment for age and gender, poor sleep efficiency (OR, 0.80; 95% CI, 0.68-0.94) was associated with higher odds of consistent noncompliance. Low ArTH (OR, 15.36; 95% CI, 1.44-164.24) increased the risk of compliance-to-noncompliance shift in this subgroup.

CONCLUSIONS

Lower BMI and low ArTH were associated with an unfavorable shift of PAP compliance over time in patients with OSA, which was different from the predictors of consistent PAP noncompliance of patients with OSA.

Low arousal threshold is associated with unfavorable shift of PAP compliance over time in patients with OSA

PURPOSE

To determine the predictive factors of initial and long-term adherence to positive airway pressure (PAP) therapy and factors leading to an unfavorable shift of PAP compliance.

METHODS

This follow-up study was comprised of newly diagnosed patients with obstructive sleep apnea (OSA) amenable to PAP therapy from January 2017 to April 2019. Information on basic demographics, comorbidities, and sleep-related symptoms were collected. PAP adherence data were collected at the end of the first week and the third month.

RESULTS

Of 166 patients enrolled, data from 142 (86%) were in the final analysis. Overall PAP usage was worse at 3 months declining from the first week. After adjusting for age and gender, multinomial logistic regression analysis showed that a small number of sleep-related symptoms (OR, 0.69; 95% CI, 0.52-0.91) and low arousal threshold (ArTH) (OR, 4.44; 95% CI, 1.52-12.98) were associated with higher odds of noncompliance. Low ArTH (OR, 2.87; 95% CI, 1.09-7.57) and lower body mass index (BMI) (OR, 0.88; 95% CI, 0.78-0.99) increased the risk of compliance-to-noncompliance shift. Sixty-two patients with polysomnography were analyzed separately. After adjustment for age and gender, poor sleep efficiency (OR, 0.80; 95% CI, 0.68-0.94) was associated with higher odds of consistent noncompliance. Low ArTH (OR, 15.36; 95% CI, 1.44-164.24) increased the risk of compliance-to-noncompliance shift in this subgroup.

CONCLUSIONS

Lower BMI and low ArTH were associated with an unfavorable shift of PAP compliance over time in patients with OSA, which was different from the predictors of consistent PAP noncompliance of patients with OSA.

Adaptive servo-ventilation in patients with chronic heart failure and sleep disordered breathing: predictors of usage

PURPOSE

Adaptive servo-ventilation (ASV) is a therapy designed for patients with central sleep apnea (CSA) and Cheyne Stokes respiration. The aim of this study was to find predictors of ASV usage in patients with CSA in a routine sleep clinic cohort.

METHODS

In this retrospective study, consecutive patients in whom ASV therapy was initiated at the University Hospital Regensburg between 2011 and 2015, were analyzed. Analysis included polysomnographies of diagnostic and ASV initiation nights, a phone questionnaire on ASV usage, readout of the ASV device 1 month after initiation ("early ASV usage," 1 month after ASV initiation), and the readout of the last month before a reappointment date set in 2015 ("late ASV usage," median 17 months after ASV initiation).

RESULTS

In 69 consecutive patients, the mean early and late ASV usage per night was 4.8 ± 2.5 h and 4.1 ± 3.0 h, respectively. Seventeen months after initiation, 57% of patients used the device ≥ 4 h per night, and of those 91% reported a subjective benefit from ASV therapy. Early ASV usage was significantly associated with late ASV usage (univariable regression: Beta 0.8, 95%CI [0.6; 1.0] p < 0.001). In multivariable regression analysis, short duration of slow wave sleep (N3) during diagnostic polysomnography (Beta - 6.2, 95%CI [- 11.0; - 1.5]; p = 0.011) and subjective benefit from ASV (Beta 174.0, 95%CI [68.6; 279.5]; p = 0.002) were significantly associated with longer late ASV usage.

CONCLUSION

Early ASV usage predicts late ASV usage. In addition, low slow wave sleep before ASV initiation and subjective benefit from ASV may contribute to higher late ASV usage.

Practical and rapidly-implemented parameters for assessing APAP titration failure

BACKGROUND

This study aimed to show the predictive value of simple polysomnographic parameters including latency of deep sleep (nREM3), latency of rapid eye movement sleep (REM), and minimum oxygen saturation (SpO₂) for predicting failure of autoadjusting positive airway pressure (APAP) titration.

METHODS

Out of 1470 patients with moderate to severe obstructive sleep apnea syndrome (OSAS) who underwent APAP titration between July 1, 2016, and December 31, 2017, 22 patients with titration failure were enrolled in the study. The demographic and polysomnographic characteristics of this group were compared with 44 patients with an adequate APAP titration who were matched with the titration failure group by age, sex, and OSAS severity. The periods between the start of sleep and the start of REM and nREM3 stages were noted as REM latency and nREM3 latency, respectively.

RESULTS

The between group differences in the parameters including nREM3 latency, REM latency, and minimum SpO₂ during the titration test were statistically significant (p = 0.004, p = 0.008, p <0.001 respectively). Possible threshold values to predict failure of APAP titration were found as 40 min and 135 min for nREM3 and REM latencies, respectively. The best threshold for minimum SpO₂ was 86% with an 86.4% of sensitivity. Despite the high negative predictive values (81% for nREM3 latency, 75% for REM latency), the sensitivities (63.6% for nREM3 latency, 54.5% for REM latency) of the prior parameters in determining titration failure were relatively low.

CONCLUSION

The minimum SpO₂ < 86% can be used as a readily available indicator of APAP titration failure. nREM3 and REM latencies may be regarded as supplementary indicators in detecting the patients who may need an advanced PAP device.

Quantifying statistical uncertainty in metrics of sleep disordered breathing

BACKGROUND

The apnea-hypopnea index (AHI) (or one of its derivatives) is the primary clinical metric for characterizing sleep disordered breathing-the value of which with respect to a threshold determines severity of diagnosis and eligibility for treatment reimbursement. The index value, however, is taken as a perfect point estimate, with no measure of statistical uncertainty. Thus, current practice does not robustly account for variability in diagnosis/eligibility due to chance. In this paper, we quantify the statistical uncertainty associated with respiratory event indices for sleep disordered breathing and the effect of uncertainty on treatment eligibility.

METHODS

We develop an empirical estimate of uncertainty using a non-parametric bootstrap on the interevent times, as well as a theoretical Poisson estimate reflecting the current formulation of the AHI. We then apply these methods to estimate AHI uncertainty for 2049 subjects (954/1095 M/F, age: mean 69 ± 9.1) from the Multi-Ethnic Study of Atherosclerosis (MESA).

RESULTS AND CONCLUSIONS

The mean 95% empirical confidence interval width was 11.500 ± 6.208 events per hour and the mean 95% theoretical Poisson confidence interval width was 5.998 ± 2.897 events per hour, suggesting that uncertainty is likely a major confounding factor within the current diagnostic framework. Of the 278 subjects in the symptomatic population (ESS>10), 27% (76/278) had uncertain diagnoses given the 95% empirical confidence interval. Of the 2049 subjects in the full population, 43% (880/2049) had uncertain diagnoses given the 95% empirical confidence interval. The inclusion of subjects with uncertain diagnoses increases the number of eligible patients by 21.3% for the symptomatic population and by 84.8% for the full population. The exclusion of subjects with uncertain diagnoses given the 95% empirical confidence interval decreases the number of eligible patients by 12.4% for the symptomatic population and by 34.8% for full population. Additional analyses suggest that it is practically infeasible to gain diagnostic statistical significance through additional testing for a broad range of borderline cases. Overall, these results suggest that AHI uncertainty is a vital additional piece of information that would greatly benefit clinical practice, and that the inclusion of uncertainty in epidemiological analysis might help improve the ability for researchers to robustly link AHI with co-morbidities and long-term outcomes.

Mindfulness may be a novel factor associated with CPAP adherence in OSAHS patients

BACKGROUND

Poor adherence to continuous positive airway pressure (CPAP) remains the greatest obstacle to effective treatment of obstructive sleep apnea-hypopnea syndrome (OSAHS). The purpose of the present study was to identify if mindfulness is associated with CPAP adherence of OSAHS patients.

METHODS

Newly diagnosed patients with OSAHS completed questionnaires including the Epworth Sleepiness Scale (ESS), the Mindful Attention Awareness Scale (MAAS), and the Hospital Anxiety and Depression Scale (HADS) and had experienced an overnight CPAP titration. Participants returned to the sleep center for a scheduled research visit after 30-day CPAP treatment at home. Demographics, disease severity, and device-related variables were collected. Multiple linear regression analysis was performed to build a multivariate predictive model for the outcome variable, mean daily CPAP use over 30 days.

RESULTS

Mean CPAP use was 4.7 ± 2.4 h/night for the study sample of 100 patients and 67% were classified as CPAP adherent. MAAS scale was 45.2 ± 18.8, whereas only 13% of patients expressed anxiety or depression. MAAS scales were significantly higher in the CPAP adherent group compared to the non-adherent group (49.5 ± 14.5 vs 40.8 ± 14.2, p < 0.001) with mean hours of daily CPAP use over 30 days for the adherent group (5.7 ± 1.4 h/night) compared to the non-adherence group (3.0 ± 1.7 h/night). There were differences between the two groups in HADS depression, AHI, lowest SaO₂, optimal CPAP pressure, residual AHI, mean days over 30 days, and mean daily CPAP use in the first week. Univariate analyses identified an unadjusted association between mean daily CPAP use over 30 days and HADS depression, MAAS, AHI, lowest SaO₂, optimal pressure, and mean daily CPAP use in the first week. Multiple linear regression analysis demonstrated only MAAS and AHI were associated (p < 0.05) with mean daily CPAP use. MAAS and AHI uniquely explained 10.1% (p < 0.001) and 8.7% (p < 0.001) of mean daily CPAP use respectively.

CONCLUSIONS

This study found a significant independent association of dispositional mindfulness with CPAP adherence. As a novel factor, mindfulness may play an important role in CPAP adherence.

Sleep Disorders and Adherence to Inhalation Therapy in Patients with Chronic Obstructive Pulmonary Disease

Sleep disorders are common in patients with chronic obstructive pulmonary disease (COPD) and are associated with greater disease severity, more frequent exacerbations, greater use of emergency health care, and higher mortality. They may contribute to worsening of COPD course by reducing patients' adherence to treatment. The aim of this study was to evaluate quality of sleep in COPD patients and to assess the relationship between impaired sleep and adherence to inhalation therapy. The study included 106 COPD patients who were asked to answer the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Adherence to Refills and Medications Scale (ARMS). Clinical and demographic data were also collected. We found that over 60% of patients presented with sleep disorders (PSQI ≥5) and 75% with daytime sleepiness. None of the patients presented with optimal adherence to pharmacotherapy. Worse adherence was correlated with greater sleep disorders (r = 0.56; p < 0.001). ARMS questionnaire proved to be of high overall internal consistency (Cronbach's alpha = 0.85). In conclusion, poor quality of sleep coexists with poor adherence to treatment among COPD patients. ARMS was proved to be a reliable tool for the assessment of adherence. Interventions aimed at improving sleep quality may be helpful to improve adherence to inhalation therapy in COPD patients.

Sleep architecture, insulin resistance and the nasal cycle: Implications for positive airway pressure therapy

Background: The global pandemic of metabolic disease is worsening. The metabolic theory of obesity proposes that hormonal changes, especially hyperinsulinaemia, precede metabolic disease development. Although quality sleep is recognised as a key factor for good health, less is known about disrupted sleep as a risk factor for hyperinsulinaemia. Aim: To explore the relationship between sleep, especially sleep architecture and the nasal cycle, on insulin secretion in obstructive sleep apnoea (OSA) with comorbid metabolic disease. This review includes a discussion of the potential role of Rest-Activity-Cycler positive airway pressure (RACer-PAP), a novel non-pharmacological OSA treatment strategy. Methods: A narrative review of all the relevant papers known to the authors was conducted. This review also included results from a polysomnographic sleep clinic pilot study (n = 3) comparing sleep efficiency of RACer-PAP to nasal continuous positive airways pressure (n-CPAP) in OSA patients.  Results: Metabolic disease is strongly associated with disturbed sleep. Sleep architecture influences cerebral hormonal secretion, lateral shifts in the autonomic nervous system and nasal airflow dominance. Disturbed sleep shortens short-wave sleep periods, decreasing insulin sensitivity and glucose tolerance. Improvements to metabolic function during n-CPAP treatment are inconsistent. If RACer-PAP demonstrates superior effects on sleep architecture and autonomic function, it may offer advantages in OSA patients with comorbid metabolic disease. Conclusion: Improving sleep architecture by maintaining the nasal cycle proposes a novel non-pharmacological treatment paradigm for treating OSA with comorbid metabolic disease. Research is required to demonstrate if RACer-PAP therapy influences whole night sleep architecture, sympathovagal balance and markers of metabolic disease.

Associations Between Sleep Quality, Sleep Architecture and Sleep Disordered Breathing and Memory After Continuous Positive Airway Pressure in Patients with Obstructive Sleep Apnea in the Apnea Positive Pressure Long-term Efficacy Study (APPLES)

Objective

The role of sleep architecture in consolidation of memory has not been extensively investigated. In this study, the association of continuous positive airway pressure (CPAP) and sleep architecture and quality, and sleep disordered breathing on changes in memory are explored during the course of a 6 month clinical trial of CPAP or sham CPAP (APPLES).

Methods

848 participants had polysomnographic and memory assessments (Buschke Selective Reminding Test [Buschke] and Digit Symbol Substitution Test [DSST]) at baseline, CPAP/Sham CPAP titration, and the 2 and 6 month time points. Half were assigned to the CPAP and Sham CPAP groups respectively. Changes in performance on the Buschke and the DSST were analyzed over the course of the study between CPAP and Sham CPAP as well as in relationship to changes in sleep architecture, sleep quality and sleep disordered breathing (SDB).

Results

Sleep architecture, sleep quality and SDB improved in the CPAP group at 6 months; performance on the Buschke and DSST improved equally in both CPAP and Sham CPAP groups. There also were no significant correlations between changes in the amount or percentage of sleep stages between baseline and the 6 months, and corresponding changes in either the Buschke or the DSST. However, when stratified by the upper quartile and lower 3 quartiles, greater changes in the Buschke occurred over 6 months in the top quartile of total sleep time (5.7±7.3 vs. 4.0±6.8, p≤0.01) and amount of N3 sleep (55.9±7.7 vs. 53.6±8.9 min, p≤0.01). Those with more %N3 at 6 months scored better on the Buschke as well (55.9±7.8 vs. 53.6±8.9, p≤0.01). Borderline improvement in the DSST over 6 months was observed in the top quartiles of amount of N3 and %N3. Those in the top quartile of the amount of REM and %REM also showed greater improvement in the Buschke after 6 months. No differences were observed for the AHI, but those in the top quartile of oxygen desaturation had worse scores on the Buschke at 6 months. CPAP/Sham CPAP adherence did not impact 6 month Buschke or DSST performance.

Conclusions

CPAP improved long-term sleep duration, quality and architecture, but did not memory. However, large changes in REM and N3 sleep as well as moderate amounts of nocturnal hypoxemia are associated with changes in assessments of memory.

Sleep apnea: a review of diagnostic sensors, algorithms, and therapies

While public awareness of sleep related disorders is growing, sleep apnea syndrome (SAS) remains a public health and economic challenge. Over the last two decades, extensive controlled epidemiologic research has clarified the incidence, risk factors including the obesity epidemic, and global prevalence of obstructive sleep apnea (OSA), as well as establishing a growing body of literature linking OSA with cardiovascular morbidity, mortality, metabolic dysregulation, and neurocognitive impairment. The US Institute of Medicine Committee on Sleep Medicine estimates that 50-70 million US adults have sleep or wakefulness disorders. Furthermore, the American Academy of Sleep Medicine (AASM) estimates that more than 29 million US adults suffer from moderate to severe OSA, with an estimated 80% of those individuals living unaware and undiagnosed, contributing to more than $149.6 billion in healthcare and other costs in 2015. Although various devices have been used to measure physiological signals, detect apneic events, and help treat sleep apnea, significant opportunities remain to improve the quality, efficiency, and affordability of sleep apnea care. As our understanding of respiratory and neurophysiological signals and sleep apnea physiological mechanisms continues to grow, and our ability to detect and process biomedical signals improves, novel diagnostic and treatment modalities emerge.

OBJECTIVE

This article reviews the current engineering approaches for the detection and treatment of sleep apnea.

APPROACH

It discusses signal acquisition and processing, highlights the current nonsurgical and nonpharmacological treatments, and discusses potential new therapeutic approaches.

MAIN RESULTS

This work has led to an array of validated signal and sensor modalities for acquiring, storing and viewing sleep data; a broad class of computational and signal processing approaches to detect and classify SAS disease patterns; and a set of distinctive therapeutic technologies whose use cases span the continuum of disease severity.

SIGNIFICANCE

This review provides a current perspective of the classes of tools at hand, along with a sense of their relative strengths and areas for further improvement.

Restoration of Sleep Architecture after Maxillomandibular Advancement: Success Beyond the Apnea-Hypopnea Index

While effects of maxillomandibular advancement (MMA) on respiratory parameters for patients with obstructive sleep apnea (OSA) are well described, effects on sleep architecture before and after MMA are not. A retrospective cohort analysis on sleep architecture was examined in 10 OSA patients who underwent MMA surgery between July 2013 and November 2014, and had prespecified complete polysomnography (PSG) datasets. Sleep stages were examined relative to a Western European population-based control group. All of the respiratory parameters improved significantly post MMA. Rapid eye movement (REM) latency decreased from 178.0±142.8 to 96.6±64.5min (P=0.035). %NREM (non-rapid eye movement)1 (P=0.045) and %WASO (wakefulness after sleep onset) (P=0.006) decreased, while %REM increased (P=0.002) after MMA. WASO decreased from 64.2±57min to 22.4±15.4min (P=0.017). Preoperatively, OSA subjects showed significantly lower sleep efficiency (P=0.016), sleep onset latency (P=0.015), and % REM (P<0.001) than the normative population dataset, while post MMA there was a significant decrease in %NREM1 sleep (P<0.001) and in %WASO (P<0.001). MMA results in a marked decrease in WASO and increase in REM, and to a lesser extent NREM sleep. Patients after MMA show values similar to population controls except for a lower WASO.

Effects of upper-airway stimulation on sleep architecture in patients with obstructive sleep apnea

PURPOSE

Selective upper-airway stimulation (UAS) is a novel therapy for patients with obstructive sleep apnea (OSA). The aim of this study was to compare changes in sleep architecture during the diagnostic polysomnography and the post-implantation polysomnography in UAS in patients with OSA.

METHODS

Twenty-six patients who received a UAS device (Inspire Medical Systems) were included. Treatment outcome was evaluated 2 and 3 months after surgery. Data collection included demographics, body mass index (BMI), apnea hypopnea index (AHI), oxygen saturation and desaturation index (ODI), Epworth sleepiness score (ESS), arousal parameter, and sleep patterns.

RESULTS

The mean age was 60.2 years, 25 patients were male, 1 patient was female. Mean BMI was 29.0 kg/m². The mean pre-implantation AHI of 33.9/h could be reduced to 9.1/h at 2 months post-implantation (p < 0.001). The amount of time spent in N1-sleep could be reduced from 23.2% at baseline to 16.0% at month 3 post-implantation. The amount of time spent in N2- and N3-sleep did not change during the observation period. A significant increase of the amount of REM sleep at month 2 (15.7%) compared to baseline (9.5%; p = 0.010) could be observed. A reduction of the number of arousals and the arousal index could be observed.

CONCLUSION

In conclusion, significant changes in sleep architecture of patients with OSA and sufficient treatment with UAS could be observed. A reduction of the amount of time spent in N1-sleep could be caused by treatment with UAS and the rebound of REM sleep, observed for the first time in a study on UAS, is also a potential marker of the efficacy of UAS on sleep architecture.

TRIAL REGISTRATION

NCT02293746.

Adherence to positive airway pressure treatment among minority populations in the US: A scoping review

Minority individuals in the United States (US) have an increased prevalence of obstructive sleep apnea (OSA) compared to their white/Caucasian counterparts. In general, adherence to positive airway pressure (PAP) therapy is poor and some studies suggest that PAP use among minority individuals is inferior to that of whites. However, there has not been a review of the evidence that addresses racial-ethnic disparities for PAP adherence in the treatment of OSA, and no review has systematically examined the contributing factors to poor adherence among minority individuals compared to whites. We searched the literature for studies published between January 1990 to July 2016 that included objective PAP use comparisons between adult US minority individuals and whites. Twenty-two studies met the inclusion criteria. All studies compared the PAP adherence of blacks to whites. Seven studies compared the PAP adherence of additional minority groups to that of whites. Sixteen of the 22 studies (73%) showed worse PAP adherence in blacks compared to whites. Four studies found equivalent PAP use in US Hispanics compared to whites. Little is known about the PAP adherence of other US minority groups. We present a framework and research agenda for understanding PAP use barriers among US minority individuals.

Sleep continuity is positively correlated with sleep duration in laboratory nighttime sleep recordings

Sleep duration varies widely across individuals and appears to be trait-like. Differences in the stability of underlying sleep processes may underlie this phenomenon. To investigate underlying mechanisms, we examined the relationship between sleep duration and sleep continuity in baseline polysomnography (PSG) recordings from three independently collected datasets: 1) 134 healthy controls (ages 37 ± 13 years) from the São Paulo Epidemiologic Sleep Study, who spent one night in a sleep laboratory, 2) 21 obstructive sleep apnea (OSA) patients who were treated with continuous positive airway pressure for at least 2 months (45 ± 12 years, respiratory disturbance index <15), who spent one night in a sleep laboratory with previous experience of multiple PSG studies, and 3) 62 healthy controls (28 ± 6 years) who, as part of larger experiments, spent 2 consecutive nights in a sleep laboratory. For each dataset, we used total sleep time (TST) to separate subjects into those with shorter sleep (S-TST) and those with longer sleep (L-TST). In all three datasets, survival curves of continuous sleep segments showed greater sleep continuity in L-TST than in S-TST. Correlation analyses with TST as a continuous variable corroborated the results; and the results also held true after controlling for age. There were no significant differences in baseline waking performance and sleepiness between S-TST and L-TST. In conclusion, in both healthy controls and treated OSA patients, sleep continuity was positively correlated with sleep duration. These findings suggest that S-TST may differ from L-TST in processes underlying sleep continuity, shedding new light on mechanisms underlying individual differences in sleep duration.

Immediate effect of CPAP titration on perceived health related quality of life: a prospective observational study

BACKGROUND

Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). This study examines changes in HRQoL aspects occurring immediately after CPAP titration. Furthermore, we analyzed variations in each gender and in patients undergoing home or laboratory-based CPAP titration pathways.

METHODS

Twohundredfive outpatients (151 M) (56.7 ± 10.3 years) were evaluated, before first visit and nocturnal diagnostic examination (T0), and the morning after CPAP titration (T1). Two self-reported HRQoL questionnaires were administered: Psychological General Well-Being Index (PGWBI), composed by six subscales, and 12-Item Short-Form Health Survey (SF-12), including Physical (PCS) and Mental Component Summaries (MCS). CPAP titration was performed using auto-adjusting CPAP units at patients' home or in the sleep laboratory.

RESULTS

PGWBI scores at T1 improved compared to T0 (p < 0.0001). A similar improvement was observed in SF-12 MCS (p = 0.0011), but not in SF-12 PCS. Changes were independent from anthropometric parameters, OSA severity and excessive daytime sleepiness. Gender comparisons showed better HRQoL in males at both times. At T0, patients who received home or laboratory CPAP titration pathways did not show any differences in PGWBI and SF-12 scores. At T1, PGWBI and SF-12 MCS improved in both home and laboratory groups.

CONCLUSIONS

This study gives evidence that first time CPAP application for titration can lead to a general increase in perceived well-being. Gender comparisons showed better perceived HRQoL with more subscales improvements in males after CPAP titration. The improvement was similar with both home and laboratory CPAP titration pathways.

In patients with minimally symptomatic OSA can baseline characteristics and early patterns of CPAP usage predict those who are likely to be longer-term users of CPAP

BACKGROUND

Long-term continuous positive airway pressure (CPAP) usage varies between individuals. It would be of value to be able to identify those who are likely to benefit from CPAP (and use it long term), versus those who would not, and might therefore benefit from additional help early on. First, we explored whether baseline characteristics predicted CPAP usage in minimally symptomatic obstructive sleep apnoea (OSA) patients, a group who would be expected to have low usage. Second, we explored if early CPAP usage was predictive of longer-term usage, as has been shown in more symptomatic OSA patients.

METHODS

The MOSAIC trial was a multi-centre randomised controlled trial where minimally symptomatic OSA patients were randomised to CPAP, or standard care, for 6 months. Here we have studied only those patients randomised to CPAP treatment. Baseline characteristics including symptoms, questionnaires [including the Epworth sleepiness score (ESS)] and sleep study parameters were recorded. CPAP usage was recorded at 2-4 weeks after initiation and after 6 months. The correlation and association between baseline characteristics and 6 months CPAP usage was assessed, as was the correlation between 2 and 4 weeks CPAP usage and 6 months CPAP usage.

RESULTS

One hundred and ninety-five patients randomised to CPAP therapy had median [interquartile range (IQR)] CPAP usage of 2:49 (0:44, 5:13) h:min/night (h/n) at the 2-4 weeks visit, and 2:17 (0:08, 4:54) h/n at the 6 months follow-up visit. Only male gender was associated with increased long-term CPAP use (male usage 2:56 h/n, female 1:57 h/n; P=0.02). There was a moderate correlation between the usage of CPAP at 2-4 weeks and 6 months, with about 50% of the variability in long-term use being predicted by the short-term use.

CONCLUSIONS

In patients with minimally symptomatic OSA, our study has shown that male gender (and not OSA severity or symptom burden) is associated with increased long-term use of CPAP at 6 months. Although, in general, early patterns of CPAP usage predicted longer term use, there are patients in whom this is not the case, and patients with low initial usage may need to extend their CPAP trial before a decision about longer-term use is made.

Obstructive sleep apnea and fatigue in head and neck cancer patients

There is a systematic relationship between fatigue, sleep, and decreased quality of life in cancer patients, with notably poor sleep quality among many head and neck cancer patients during and after treatment. An often overlooked cause of sleep disturbance in this patient population is obstructive sleep apnea (OSA). This review explores the current literature on the prevalence and clinical correlates of OSA, management outcomes, and data on cytokine-mediated fatigue in OSA. OSA appears to be prevalent in head and neck cancer patients, both at baseline and after treatment, especially with multimodality therapy including radiation therapy. Predictors of developing OSA include larger tumor size and hypopharynx or larynx primary site. There is evidence that the level of fatigue seen in these patients is not necessarily correlated with the severity of their OSA. Current research highlights the role of proinflammatory cytokines, which can also be synergistically activated by radiation therapy, as mediators of fatigue. Primary management of OSA consists of continuous positive airway pressure. Although continuous positive airway pressure has been shown to improve clinical symptoms, compliance with its use remains a problem and will be an area of future research.

A comparison of CPAP and CPAPFLEX in the treatment of obstructive sleep apnea in World Trade Center responders: study protocol for a randomized controlled trial

Background

Following the World Trade Center disaster, a large number of individuals involved in rescue and recovery activity were exposed to significant amounts of dust, and reported symptoms of chronic nasal and sinus inflammation. An unusually high prevalence of obstructive sleep apnea (OSA) has also been observed in this World Trade Center Responder population. This project aims to examine the relationship between nasal pathology and OSA. Our hypothesis is that increased nasal resistance due to nasal inflammation predisposes to OSA in this population. Continuous Positive Airway Pressure (CPAP) is the standard therapy for OSA but despite its efficacy has poor adherence. Subjects with high nasal resistance may have greater difficulty in tolerating this therapy than those who do not have high nasal resistance. Reduction of excess expiratory positive pressure by the modality known as Cflex™ during Continuous Positive Airway Pressure therapy (CPAP_Flex) has been suggested to improve comfort without compromising efficacy. We will compare CPAP to CPAP_Flex in subjects with OSA.

Study Design

Subjects with new onset habitual snoring will be screened for OSA using home sleep studies and rhinomanometry will be used to determine nasal resistance. In 400 subjects with OSA we will perform a randomized double blind cross-over study comparing CPAP to CPAP_flex, and relate nasal resistance to adherence to CPAP therapy.

Discussion

This is the first multicenter trial designed to test the hypothesis that adherence to CPAP therapy relates to nasal resistance and CPAP_Flex will improve adherence to CPAP in those subjects with high nasal resistance.

We anticipate the following results from this trial: 1. Increased nasal resistance is associated with decreased adherence to CPAP therapy. 2. Use of CPAP_Flex improves adherence with CPAP therapy in subjects with high nasal resistance, but not in those with low nasal resistance. 3. The benefit of CPAP_Flex on adherence is greatest when offered at CPAP therapy initiation rather than as a “rescue” therapy in subjects with high nasal resistance.

Trial Registration

ClinicalTrials.gov Identifier: NCT01753999, Date: 12 December 2012

Positive airway pressure and electrical stimulation methods for obstructive sleep apnea treatment: a patent review (2005 - 2014)

INTRODUCTION

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a major health problem with significant negative effects on the health and quality of life. Continuous positive airway pressure (CPAP) is currently the primary treatment option and it is considered the most effective therapy for OSAHS. Nevertheless, comfort issues due to improper fit to patient's changing needs and breathing gas leakage limit the patient's adherence to treatment.

AREAS COVERED

The present patent review describes recent innovations in the treatment of OSAHS related to optimization of the positive pressure delivered to the patient, methods and systems for continuous self-adjusting pressure during inspiration and expiration phases, and techniques for electrical stimulation of nerves and muscles responsible for the airway patency.

EXPERT OPINION

In the last few years, CPAP-related inventions have mainly focused on obtaining an optimal self-adjusting pressure according to patient's needs. Despite intensive research carried out, treatment compliance is still a major issue. Hypoglossal electrical nerve stimulation could be an effective secondary treatment option when CPAP primary therapy fails. Several patents have been granted focused on selective stimulation techniques and parameter optimization of the stimulating pulse waveform. Nevertheless, there remain important issues to address, like effectiveness and adverse events due to improper stimulation.

Pre- and in-therapy predictive score models of adult OSAS patients with poor adherence pattern on nCPAP therapy

OBJECTIVES

To identify patterns of adherence to nasal continuous positive airway pressure (nCPAP) use in the first 3 months of therapy among newly diagnosed adult patients with obstructive sleep apnea/hypopnea syndrome (OSAS) and their predictors. To develop pretherapy and in-therapy scores to predict adherence pattern.

METHODS

Newly diagnosed adult OSAS patients were consecutively recruited from March to August 2013. Baseline clinical information and measures such as Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), Zung's Self-Rating Depression Scale (SDS), and The Pittsburgh Sleep Quality Index (PSQI) at baseline and at the end of 3rd-week therapy were collected. Twelve weeks' adherence data were collected from the nCPAP memory card, and K-means cluster analysis was used to explore adherence patterns. Predictive scores were developed from the coefficients of cumulative logit models of adherence patterns using variables available at baseline and after 3 weeks of therapy. Performance of the score was validated using 500 bootstrap resamples.

RESULTS

Seventy six patients completed a 12-week follow-up. Three patterns were revealed. Patients were identified as developing an adherence pattern that was poor (n=14, mean ± SD, 2.3±0.9 hours per night), moderate (n=19, 5.3±0.6 hours per night), or good (n=43, 6.8±0.3 hours per night). Cumulative logit regression models (good → moderate → poor) revealed independent baseline predictors to be ESS (per unit increase) (OR [95% CI], 0.763 [0.651, 0.893]), SDS (1.461 [1.238, 1.724]), and PSQI (2.261 [1.427, 3.584]); and 3-week therapy predictors to be ESS (0.554 [0.331, 0.926]), PSQI (2.548 [1.454, 4.465]), and the changes (3rd week-baseline data) in ESS (0.459 [0.243, 0.868]), FSS (3.556 [1.788, 7.070]), and PSQI (2.937 [1.273, 6.773]). Two predictive score formulas for poor adherence were developed. The area under the curve (AUC) of the receiver operating characteristics (ROC) curves for baseline and 3-week formulas were 0.989 and 0.999, respectively. Bootstrap analysis indicated positive predictive values of baseline and 3-week predictive scores in our patient population of 0.82 (95% CI [0.82, 0.83]) and 0.94 (95% CI [0.93, 0.94]), respectively.

CONCLUSION

A high level of prediction of poor adherence pattern is possible both before and at the first 3 weeks of therapy. The predictive scores should be further evaluated for external validity.

A visit to Absurdistan: a nightmare of a sleep specialist

During a nocturnal dream, the authors discover a strange and unknown country, Absurdistan. Absurdistanis main concern appears to be sleep, whether nocturnal or diurnal, rather than wakefulness. They are fond of sleeping in any form, and devote much time to this activity. The authors follow a guide that shows them all kinds of strange sleep habits and keeps explaining the complex as well as the obvious. As the journey evolves, the explanations turn more and more confusing, becoming also amazingly surrealistic. The dream ends with a welcome wakefulness leaving the authors unsure of which is the waking state and which the dream.