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)

Surgical treatment for obstructive sleep apnea: effect on sleep architecture

PURPOSE

Investigate the effect of surgical treatment of obstructive sleep apnea syndrome (OSA) on sleep architecture.

METHODS

Observational retrospective analysis of polysomnographic data of adults diagnosed with OSA, submitted to surgical treatment. Median (25-75th percentile) was used to present the data.

RESULTS

Data were available for 76 adults, 55 men and 21 women, with median age of 49.0 years (41.0-62.0), body mass index of 27.3 kg/m2 (25.3-29.3) and AHI of 17.4 per hour (11.3-22.9) before surgeries. Preoperatively, 93.4% of patients had an abnormal distribution of at least one of the sleep phases. After surgical treatment, we found a significant increase in median N3 sleep percent from 16.9% (8.3-22-7) to 18.9% (15.5-25.4) (p = 0.003). Postoperatively, 18.6% patients that had an abnormal preoperative N1 sleep phase distribution had a normalization of this sleep phase, as also occurred to N2, N3 and REM sleep phases in 44.0%, 23.3% and 63.6% of patients, respectively.

CONCLUSION

This study aims to show the impact of OSA treatment, not only on respiratory events but also on other polysomnographic data often underestimated. Upper airway surgeries have shown to be effective in sleep architecture improvements. There is a trend for sleep distribution normalization, with increase of time spend in profound sleep.

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.

The Effect of Obstructive Sleep Apnea on Sleep-dependent Emotional Memory Consolidation

Rationale: A growing body of evidence suggests that sleep is critical for the adaptive processing and consolidation of emotional information into long-term memory. Previous research has indicated that emotional components of scenes particularly benefit from sleep in healthy groups, yet sleep-dependent emotional memory processes remain unexplored in clinical cohorts, including those with obstructive sleep apnea (OSA). This line of research is important as it will add to the understanding of how disrupted sleep in OSA contributes to both impaired cognition and emotion dysregulation. Objectives: To test the hypothesis that individuals with OSA will have impaired sleep-dependent memory consolidation, with the greatest impact being on memory for emotional content. Methods: In this study, a group of newly diagnosed patients with OSA (n = 26; 10 female; average age, 42.5 years) and a matched group of healthy control subjects (n = 24; 13 female; average age, 37 years) were enrolled in the study at Beth Israel Deaconess Medical Center. Participants encoded scenes with negative or neutral foreground objects placed on neutral backgrounds before a night of polysomnographically recorded sleep. In the morning, they completed a recognition test in which old and new scene objects and backgrounds, presented separately and one at a time, were judged as old, new, or similar compared with what had been previously viewed. Results: Patients with OSA had a deficit in recognition memory for the scenes. Overall recognition (the ability to recognize old items as either old or similar) was impaired across all scene elements, both negative and neutral objects and backgrounds, whereas specific recognition (correctly identifying old items as old) was impaired only for negative objects. Across all participants, successful overall recognition correlated positively with sleep efficiency and rapid eye movement (REM) sleep, whereas successful specific memory recognition correlated only with REM sleep. Conclusions: Our findings indicate that fragmented sleep and reduced REM sleep, both hallmarks of OSA, are associated with disruptions in general memory impairment and veridical memory for emotional content, which could alter emotional regulation and contribute to comorbid emotional distress in OSA.

Effects of CPAP treatment on electroencephalographic activity in patients with obstructive sleep apnea syndrome during deep sleep: Preliminary findings of a cross-sectional study

Study objectives: To investigate whether electroencephalographic (EEG) activities during non-rapid eye movement sleep stage 3 (N3) in obstructive sleep apnea syndrome (OSAS) patients were changed with continuous positive airway pressure (CPAP) treatment.Methods: A cross-sectional study of EEG activity during N3 sleep was conducted in 15 patients with moderate to severe OSAS without and with CPAP treatment compared to 15 normal controls. The amplitude, and absolute and relative power of delta, theta, alpha and beta waves as well as the absolute power ratio of slow to fast EEG waves (i.e., absolute power of delta and theta waves/absolute power of alpha and beta waves) and the spectral power density of 0-30 Hz EEG activities were analyzed.Results: CPAP significantly increased N3 sleep, the absolute and relative powers, amplitudes of delta and theta waves, and absolute power ratio of slow to fast EEG waves, but decreased relative alpha and beta powers during N3 sleep. However, there were no significant differences in those parameters between the OSAS patients with CPAP treatment and normal controls.Conclusions: CPAP prolongs N3 sleep and increases the power and amplitude of slow EEG waves during N3 sleep, which indicates an improvement in sleep quality and further provides evidence for recommendation of CPAP treatment for OSAS patients.

Effects of continuous positive airway pressure treatment on sleep architecture in adults with obstructive sleep apnea and type 2 diabetes

Obstructive sleep apnea (OSA) severely impacts sleep and has long-term health consequences. Treating sleep apnea with continuous positive airway pressure (CPAP) not only relieves obstructed breathing, but also improves sleep. CPAP improves sleep by reducing apnea-induced awakenings. CPAP may also improve sleep by enhancing features of sleep architecture assessed with electroencephalography (EEG) that maximize sleep depth and neuronal homeostasis, such as the slow oscillation and spindle EEG activity, and by reducing neurophysiological arousal during sleep (i.e., beta EEG activity). We examined cross-sectional differences in quantitative EEG characteristics of sleep, assessed with power spectral analysis, in 29 adults with type 2 diabetes treated with CPAP and 24 adults undergoing SHAM CPAP treatment (total n = 53). We then examined changes in spectral characteristics of sleep as the SHAM group crossed over to active CPAP treatment (n = 19). Polysomnography (PSG) from the CPAP titration night was used for the current analyses. Analyses focused on EEG frequencies associated with sleep maintenance and arousal. These included the slow oscillation (0.5–1 Hz), sigma activity (12–16 Hz, spindle activity), and beta activity (16–20 Hz) in F3, F4, C3, and C4 EEG channels. Whole night non-rapid eye movement (NREM) sleep and the first period of NREM spectral activity were examined. Age and sex were included as covariates. There were no group differences between CPAP and SHAM in spectral characteristics of sleep architecture. However, SHAM cross-over to active CPAP was associated with an increase in relative 12–16 Hz sigma activity across the whole night and a decrease in average beta activity across the whole night. Relative slow oscillation power within the first NREM period decreased with CPAP, particularly for frontal channels. Sigma and beta activity effects did not differ by channel. These findings suggest that CPAP may preferentially enhance spindle activity and mitigate neurophysiological arousal. These findings inform the neurophysiological mechanisms of improved sleep with CPAP and the utility of quantitative EEG measures of sleep as a treatment probe of improvements in neurological and physical health with CPAP.

Six Months of Inspiratory Muscle Training to Lower Blood Pressure and Improve Endothelial Function in Middle-Aged and Older Adults With Above-Normal Blood Pressure and Obstructive Sleep Apnea: Protocol for the CHART Clinical Trial

Background: Cardiovascular disease is a major global health concern and prevalence is high in adults with obstructive sleep apnea (OSA). Lowering blood pressure (BP) can greatly reduce cardiovascular disease risk and physical activity is routinely prescribed to achieve this goal. Unfortunately, many adults with OSA suffer from fatigue, daytime sleepiness, and exercise intolerance—due to poor sleep quality and nocturnal hypoxemia—and have difficulty initiating and maintaining an exercise program. High-resistance inspiratory muscle strength training (IMST) is a simple, time-efficient breathing exercise consistently reported to reduce BP in small, selective groups of both healthy and at-risk adults. Herein we present the study protocol for a randomized clinical trial to determine the long-term efficacy of IMST performed regularly for 24 weeks in middle-aged and older adults with OSA. The primary outcome is casual systolic BP. Secondary outcomes are 24-h systolic BP and circulating plasma norepinephrine concentration. Other outcomes include vascular endothelial function (endothelial-dependent and -independent dilation), aortic stiffness, casual and 24-h diastolic BP, and the influence of circulating factors on endothelial cell nitric oxide and reactive oxygen species production. Overall, this trial will establish efficacy of high-resistance IMST for lowering BP and improving cardiovascular health in middle-aged and older adults with OSA.

Methods: This is a single-site, double-blind, randomized clinical trial. A minimum of 92 and maximum of 122 male and female adults aged 50–80 years with OSA and above-normal BP will be enrolled. After completion of baseline assessments, subjects will be randomized in a 1:1 ratio to participate in either high-resistance or sham (low-resistance) control IMST, performed at home, 5 min/day, 5 days/week, for 24 weeks. Repeat assessments will be taken after the 24-week intervention, and after 4 and 12 weeks of free living.

Discussion: This study is designed to assess the effects of 24 weeks of IMST on BP and vascular function. The results will characterize the extent to which IMST can reduce BP when performed over longer periods (i.e., 6 months) than have been assessed previously. Additionally, this study will help to determine underlying mechanisms driving IMST-induced BP reductions that have been reported previously.

Clinical Trial Registration: This trial is registered with ClinicalTrials.gov (Registration Number: NCT04932447; Date of registration June 21, 2021).

Health outcomes of continuous positive airway pressure versus mandibular advancement device for the treatment of severe obstructive sleep apnea: an individual participant data meta-analysis

STUDY OBJECTIVES

The impact of therapy with continuous positive airway pressure (CPAP) and mandibular advancement device (MAD) has not been directly compared in patients with severe obstructive sleep apnea (OSA). The purpose of this individual participant data meta-analysis was to compare the treatment effects of CPAP and titratable MAD on sleepiness, quality of life, sleep-disordered breathing severity, and sleep structure in patients with severe OSA.

METHODS

Randomized controlled trials (RCTs) that included severe OSA patients were identified in order to compare the impact of the two treatments. Individual data from severe OSA patients were extracted from the databases and pooled for analysis.

RESULTS

Of the seven studies identified, three crossover RCT and one parallel-group RCT corresponding to 151 patients and 249 observations (125 in the CPAP treatment arm and 124 in the MAD treatment arm) were included in the analysis. Titratable MAD had a similar impact to CPAP on major patient-centered outcomes (sleepiness and quality of life). CPAP was more effective in reducing AHI and ODI. However, the two treatments had a similar impact on sleep structure with an increase of N3 and REM sleep. Finally, treatment adherence and preference were largely in favor of MAD.

CONCLUSION

This meta-analysis suggests that MAD represents an effective alternative treatment in severe OSA patients intolerant to CPAP or who prefer alternate therapy.

When Traumatic Memories Affect Your Health: A Clinical Case Study

Obstructive sleep apnea hypopnea (OSA) is the most common breathing-related sleep disorder and affects more than 20% of older individuals. Furthermore, risk of OSA increases in postmenopausal women. OSA is effectively treated using continuous positive airway pressure (CPAP). However, Mary, a 74-year-old White woman with OSA, severe, refused to obtain a CPAP machine because the sound of the machine elicited memories of her late husband’s suicide. Intervention focused on reducing Mary’s fear of CPAP sounds. Treatment involved imaginal exposure, in vivo exposure, sleep hygiene strategies, and relaxation strategies. Although evidence-based treatments for OSA and trauma separately exist, there are no treatment protocols designed to address the specific combination of the conditions. Treatment gains included a reduction in trauma-related symptoms and an increase in CPAP compliance. Quantity and quality of patient’s sleep did not improve despite sleep hygiene and CPAP use. At 3-week follow-up, treatment gains and CPAP compliance were maintained.

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.