Validation of a sleep staging classification model for healthy adults based on two combinations of a single-channel EEG headband and wrist actigraphy.

STUDY OBJECTIVES: The aim of this study was to develop a sleep staging classification model capable of accurately performing on different wearable devices. METHODS: Twenty-three healthy subjects underwent a full-night type I polysomnography and used two devices' combinations: (A) flexible single-channel electroencephalogram headband+actigraphy (N=12) and (B) rigid single-channel electroencephalogram headband+actigraphy (N=11). The signals were segmented into 30-second epochs according to polysomnographic stages (scored by a board-certified sleep technologist) (model ground truth) and 18 frequency and time features were extracted. The model consisted of an ensemble of bagged decision trees. Bagging refers to bootstrap aggregation to reduce overfitting and improve generalization. To evaluate the model, a training dataset under 5-fold cross-validation and an 80-20% dataset split was used. The headbands were also evaluated without the actigraphy feature. Subjects also completed a usability evaluation (comfort, pain while sleeping, and sleep disturbance). RESULTS: Combination A had an F1-score of 98.4% and the flexible headband alone of 97.7% (error rate for N1: combination A=9.8%; flexible headband alone=15.7%). Combination B had an F1-score of 96.9% and the rigid headband alone of 95.3% (error rate for N1: combination B=17.0%; rigid headband alone=27.7%); in both, N1 was more confounded with N2. CONCLUSIONS: We developed an accurate sleep classification model based on a single-channel EEG device, and actigraphy was not an important feature of the model. Both headbands were found to be useful, with the rigid one being more disruptive to sleep. Future research can improve our results by applying the developed model in a population with sleep disorders. CLINICAL TRIAL REGISTRATION: Actigraphy, Wearable EEG Band and Smartphone for Sleep Staging (ID NCT04943562).

Guidelines for the development, performance evaluation and validation of new sleep technologies (DEVSleepTech guidelines) - a protocol for a Delphi consensus study.

New sleep technologies are being developed, refined and delivered at a fast pace. However, there are serious concerns about the validation and accuracy of new sleep-related technologies being made available, as many of them, especially consumer-sleep technologies, have not been tested in comparison with gold-standard methods or have been approved by health regulatory agencies. The importance of proper validation and performance evaluation of new sleep technologies has already been discussed in previous studies and some recommendations have already been published, but most of them do not employ standardized methodology and are not able to cover all aspects of new sleep technologies. The current protocol describes the methods of a Delphi consensus study to create guidelines for the development, performance evaluation and validation of new sleep devices and technologies. The resulting recommendations are not intended to be used as a quality assessment tool to evaluate individual articles, but rather to evaluate the overall procedures, studies and experiments performed to develop, evaluate performance and validate new technologies. We hope these guidelines can be helpful for researchers who work with new sleep technologies on the appraisal of their reliability and validation, for companies who are working on the development and refinement of new sleep technologies, and by regulatory agencies to evaluate new technologies that are looking for registration, approval or inclusion on health systems.

A cross-sectional analysis of the association between sleep disorders and cancer using data from the National Health and Nutrition Examination Survey (NHANES) 2005-2014.

STUDY OBJECTIVES: Cancer is one of the main causes of death in the world, while sleep disorders are a serious public health problem, especially in large cities, insomnia and obstructive sleep apnea (OSA) being the most common. In the last decade, studies have pointed to a possible association between sleep disorders and cancer. The aim of this study is to evaluate whether there is any association between sleep disorders and cancer diagnosis. METHODS: Five National Health and Nutrition Examination Surveys (NHANES) (2005-2014) from the United States were combined in order to obtain the sample. Two main sleep variables were assessed: having trouble sleeping and/or ever telling a doctor you had a sleep problem. The odds ratio of ever having a cancer diagnosis was the main outcome. Data was analyzed by binary logistic regression models in Jamovi. RESULTS: The final sample comprised 26,821 participants. Individuals who reported having trouble sleeping had an odds ratio (OR)=1.48 (95% CI=[1.336-1.646]; p<0.001) of having been diagnosed with cancer, and those who had already been diagnosed with a sleep disorder presented an OR=1.21 (95% CI=[1.046-1.415]; p=0.011), showing an increased chance of having been diagnosed with cancer. In men, these values were even greater, presenting an OR=1.56 (95% CI=[1.321-1.843]; p<0.001) and an OR=1.26 (95% CI=[1.013-1.582]; p=0.037), respectively, for having trouble sleeping and for having been diagnosed with a sleep disorders, in relation to having been diagnosed with cancer. CONCLUSIONS: Individuals who had trouble sleeping or who had been diagnosed with a sleep disorder at any time in their life were more likely to have been diagnosed with cancer.

Methods for REM Sleep Density Analysis: A Scoping Review.

Rapid eye movements (REM) sleep density is the parameter proposed to explain the variability in the amount of eye movements during REM sleep. Alterations in REM sleep density have been proposed as a screening criterion for individuals with depression and other mental health conditions, but its accuracy has not been properly evaluated. The lack of consensus and the variability of the methods used to score it reduces the external validity of the results, hindering an adequate analysis of its diagnostic accuracy and clinical applicability. This scoping review aimed to identify and quantify the methods used to score REM sleep density, describing their main characteristics. A literature search was conducted in PubMed, Scopus, PsycInfo, and Web of Science. Only studies with objective measures for REM sleep density analysis in individuals with depression were considered eligible. The final sample comprised 57 articles, covering 64 analyses of REM sleep density. The relative frequency methods were the predominant measurement parameter for analyzing REM sleep density across studies. The most frequently adopted REM estimation unit was the number of REM events followed by mini-epochs containing REM. The most common unit of measurement were frequency/time measures. The results demonstrate that there is no consistency in the methods used to calculate REM sleep density in the literature, and a high percentage of studies do not describe their methods in sufficient detail. The most used method was the number of REM episodes per minute of REM sleep, but its use is neither unanimous nor consensual. The methodological inconsistencies and omissions among studies limit the replicability, comparability, and clinical applicability of REM sleep density. Future guidelines should discuss and include a specific methodology for the scoring of REM sleep density, so it can be consensually implemented in clinical services and research.

Impact of the early months of the COVID-19 pandemic on the sleep patterns of a Brazilian population sample.

Humanitarian and health crisis have drastic effects on the physical and mental well-being of people. The COVID-19 pandemic forced many countries to impose containment measures on its population to halt the spread of the new coronavirus (SARS-CoV-2). This aim of this study was to explore self-reported sleep quality and insomnia symptoms in a sample of the Brazilian population before and during the COVID-19 quarantine period. Our data was collected through online questionnaires, including the Pittsburgh Sleep Quality Index, the Insomnia Severity Index, and the Sleep Hygiene Index. The final sample comprised 1,109 volunteers. Generalized estimating equations (GEE) revealed that during the initial months of the COVID-19 pandemic, alterations in self-reported sleep parameters were observed in the participants. Sleep efficiency and sleep duration increased, but there was a worsening in sleep quality and an increase in symptoms related to insomnia.

Perspective: Systematic review and meta-analysis in obstructive sleep apnea - What is lacking?

Obstructive sleep apnea (OSA) affects nearly one billion of the global adult population. It is associated with substantial burden in terms of quality of life, cognitive function, and cardiovascular health. Positive airway pressure (PAP) therapy, commonly considered the first-line treatment, is limited by low compliance and lacking efficacy on long-term cardiovascular outcomes. A substantial body of research has been produced investigating (novel) non-PAP treatments. With increased understanding of OSA pathogenesis, promising therapeutic approaches are emerging. There is an imperative need of high-quality synthesis of evidence; however, current systematic reviews and meta-analyses (SR/MA) on the topic demonstrate important methodological limitations and are seldom based on research questions that fully reflect the complex intricacies of OSA management. Here, we discuss the current challenges in management of OSA, the need of treatable traits based OSA treatment, the methodological limitations of existing SR/MA in the field, potential remedies, as well as future perspectives.

Exploring the potential relationships among obstructive sleep apnea, erectile dysfunction, and gut microbiota: a narrative review.

INTRODUCTION: Poor sleep quality is closely associated with comorbidities affecting a multitude of organ systems. Among the sleep disorders in the population, there has recently been an increase in the prevalence of obstructive sleep apnea (OSA), which has particularly affected men. The intermittent hypoxia and sleep fragmentation associated with OSA can result in the manifestation or aggravation of a number of pathophysiologic conditions, including the impairment of reproductive function in men and women. In this context, erectile dysfunction (ED) is of particular concern. Other consequences of OSA are changes in the gastrointestinal microbiota, with the resultant dysbiosis having potentially harmful consequences that promote downstream exacerbation of various comorbidities. OBJECTIVES: This narrative review aims to explore the potential relationships among ED, gut microbiota, and OSA. METHODS: A search of the relevant literature was performed in the PubMed, Embase, Medline, and Web of Science databases. RESULTS: Sleep is important for regulating the body's functions, and sleep deprivation can negatively affect health. OSA can damage organic functions, including reproductive function, and can lead to ED. Restoring the microbiota and improving sleep can help to improve sexual function or reverse ED and enhance other associated conditions mediated through the gut-brain axis relationship. Probiotics and prebiotics can be used as supportive strategies in the prevention and treatment of OSA, as they help to reduce systemic inflammation and improve intestinal barrier function. CONCLUSION: A good diet, a healthy lifestyle, and proper bowel function are essential in controlling depression and several other pathologies. Modulating the gut microbiota through probiotics and prebiotics can provide a viable strategy for developing new therapeutic options in treating many conditions. A better understanding of these a priori unrelated phenomena would foster our understanding of the effects of OSA on human fertility and how changes in gut microbiota may play a role.

Consumer sleep technology for the screening of obstructive sleep apnea and snoring: current status and a protocol for a systematic review and meta-analysis of diagnostic test accuracy.

There are concerns about the validation and accuracy of currently available consumer sleep technology for sleep-disordered breathing. The present report provides a background review of existing consumer sleep technologies and discloses the methods and procedures for a systematic review and meta-analysis of diagnostic test accuracy of these devices and apps for the detection of obstructive sleep apnea and snoring in comparison with polysomnography. The search will be performed in four databases (PubMed, Scopus, Web of Science, and the Cochrane Library). Studies will be selected in two steps, first by an analysis of abstracts followed by full-text analysis, and two independent reviewers will perform both phases. Primary outcomes include apnea-hypopnea index, respiratory disturbance index, respiratory event index, oxygen desaturation index, and snoring duration for both index and reference tests, as well as the number of true positives, false positives, true negatives, and false negatives for each threshold, as well as for epoch-by-epoch and event-by-event results, which will be considered for the calculation of surrogate measures (including sensitivity, specificity, and accuracy). Diagnostic test accuracy meta-analyses will be performed using the Chu and Cole bivariate binomial model. Mean difference meta-analysis will be performed for continuous outcomes using the DerSimonian and Laird random-effects model. Analyses will be performed independently for each outcome. Subgroup and sensitivity analyses will evaluate the effects of the types (wearables, nearables, bed sensors, smartphone applications), technologies (e.g., oximeter, microphone, arterial tonometry, accelerometer), the role of manufacturers, and the representativeness of the samples.

The effects of hormonal contraceptive use on sleep in women: A systematic review and meta-analysis.

Hormonal contraceptives are some of the most widely used medications worldwide, but studies on their effects on sleep are contradictory, with some reporting a sleep-promoting effect, while others a sleep-inhibiting effect. Our objective was, therefore, to undertake a systematic review and meta-analysis of the literature on this subject to try to clarify their effects. A search was conducted in three databases (PubMed, Scopus and Web of Science). Only studies evaluating hormonal contraception use were considered eligible, and both objective and subjective sleep-related outcomes were considered. Individual effect size was calculated for each article, and meta-analyses were performed using a DerSimonian and Laird random effects method. The initial search identified 2076 articles, of which 13 met the criteria for the study after full text evaluation. A total of 33 meta-analyses were performed, three of them related to subjective measures and 30 considering data from polysomnography. The only statistically significant result between contraceptive users and non-contraceptive users was observed in respect of wake after sleep onset, which was 7 min shorter among contraceptive users (-7.12 [-12.80; -1.44]; I2  = 65%; p = 0.01). In conclusion, hormonal contraceptives are not associated with clinically relevant changes in sleep patterns in women.

The Effects of Hormonal Contraceptives on the Sleep of Women of Reproductive Age.

Research about the effects of hormonal contraceptives on sleep has been performed but is subjected to important levels of methodological heterogeneity. Hormonal contraceptives impact sleep, but the direction of this association is not clear. Most studies describe a negative sleep profile among contraceptive users, including increased sleepiness, insomnia symptoms, decreased sleep efficiency, and a reduced overall sleep quality. Hormonal intrauterine contraceptives are associated with less negative effects. More research on the field, especially randomized controlled trials, is needed to increase the level and certainty of evidence about the effects of hormonal contraceptives on sleep.

The Impact of Maternity and Working Demands in Women's Sleep Pattern.

This literature review seeks to understand how motherhood and profession affect women's sleep. After the birth of a child, there is an increase in dissatisfaction with the quantity and quality of sleep. Awakenings and sleep disturbances are more frequent and can lead to increased fatigue and stress to reconcile household activities and work demands. These changes in sleep can lead to physical and/or psychological health problems. Sleep hygiene and social support become fundamental for the performance of the maternal tasks, reducing risks and increasing prevention of future problems, both for women and children.

An Overview of the Methods Used to Measure the Impact of Mindfulness-Based Interventions in Sleep-Related Outcomes.

Introduction Systematic reviews and metanalyses have shown that mindfulness-based interventions can have positive effects on health, such as reducing anxiety, depression, and chronic pain. However, their effect on sleep-related outcomes is not yet well established. Sleep can be assessed subjectively (questionnaires, sleep logs, self-reporting) and/or objectively (actigraphy, polysomnography, biological markers), and outcomes may differ depending on which type of assessment is used. Objective In this study, we present a literature overview on mindfulness and sleep, innovatively presenting and discussing studies that address sleep subjectively and objectively. Methods The search was undertaken using four databases (Pubmed Medline, Scopus, Web of Science, Psychinfo) in September 2019, and repeated in May 2021. Studies were analyzed through a two-step process: (1) reading titles and abstracts, and (2) full text analysis that met the review's eligibility criteria, with the final sample comprising 193 articles. We observed a growth in the number of studies published, particularly since 2005. However, this was mostly due to an increase in studies based on subjective research. There is a moderate to nonexistent agreement between objective and subjective sleep measures, with results of subjective measures having higher variability and uncertainty.We identified 151 articles (78%) using an exclusively subjective sleep evaluation, which can cause a misperception about mindfulness effects on sleep. Conclusion Future studies should place greater emphasis on objective measurements to accurately investigate the effects of mindfulness practices on sleep, although subjective measures also have a role to play in respect of some aspects of this relationship.

Brazilian Consensus on Sleep-Focused Speech-Language-Hearing Sciences - 2023 Brazilian Sleep Association.

Introduction This consensus aimed to develop a structured document presenting the role of sleep-focused Speech-Language-Hearing (SPH) Sciences (SPHS). The recommendations were based on the expertise of specialists and on evidence in the literature, aiming to guide the coverage of this area and the consequent improvement in the quality of the professionals' approach. Methods A Delphi method was conducted with 49 SLH pathologists (SLHP), four sleep physicians, one dentist, one physical therapist, and one methodologist. Four Delphi panel rounds were conducted in Google Forms. The items were analyzed based on the panelists' percentage of agreement; consensuses were reached when ⅔ (66.6%) of valid responses were on a same on a same answer (either "agree" or "disagree"). Results Participants voted on 102 items. The mean consensus rate was 89.9% ± 10.9%. The essential topics were the importance of professional training, the SLH diagnosis, and the SLH treatment of sleep disorders. It was verified that all fields of the SLHS are related to the area of sleep; that sleep-focused SLH pathologists (SLHP) are the responsible for assessing, indicating, and conducting specific orofacial myofunctional therapy for sleep-disordered breathing alone or in combination with other treatments; that SLHP are included in interdisciplinary teams in the area of sleep in public and private services. Discussion The Brazilian consensus on sleep-focused SLHS is a landmark in this area. This consensus described the scope of action of sleep-focused SLHP and systematized recommendations being useful as a reference for the professional practice in the area of sleep.

2023 Guidelines on the Diagnosis and Treatment of Insomnia in Adults - Brazilian Sleep Association.

Chronic insomnia disorder (simplified in this document as insomnia) is an increasingly common clinical condition in society and a frequent complaint at the offices of different areas of health practice (particularly Medicine and Psychology). This scenario has been accompanied by a significant evolution in treatment, as well as challenges in approaching patients in an appropriately way. This clinical guideline, coordinated by the Brazilian Sleep Association and the Brazilian Association of Sleep Medicine and counting on the active participation of various specialists in the area, encompasses an update on the diagnosis and treatment of insomnia in adults. To this end, it followed a structured methodology. Topics of interest related to diagnosis were written based on theoretical framework, evidence in the literature, and professional experience. As for the topics related to the treatment of insomnia, a series of questions were developed based on the PICO acronym (P - Patient, problem, or population; I - Intervention; C - Comparison, control, or comparator; O - Outcome). The work groups defined the eligible options within each of these parameters. Regarding pharmacological interventions, only the ones currently available in Brazil or possibly becoming available in the upcoming years were considered eligible. Systematic reviews were conducted to help prepare the texts and define the level of evidence for each intervention. The final result is an objective and practical document providing recommendations with the best scientific support available to professionals involved in the management of insomnia.

Interest Groups as an Alternative for Medical Education in Sleep Medicine: Experience Report at a Brazilian Medical School.

Sleep medicine classes and teachings are usually deficient and insufficient during undergraduate medical education. In order to circumvent the educational deficits in sleep medicine, students at a Brazilian Medical School created a sleep medicine interest group-an academic organization for teaching purposes whose administration is carried out by the undergraduate students themselves. This study aims to describe the establishment of a sleep medicine interest group, as well as to evaluate the results of its first edition on the knowledge about sleep medicine among undergraduate medical students. Classes were taken biweekly and consisted of lectures by invited professors, presentation of clinical cases, and discussion with the students. By the end of the course, both attendees and non-attendees were invited to fill out a questionnaire including an objective assessment of knowledge (15 multiple choice questions). The questionnaire was filled out by 32 participants, of which 18 were attendees and 14 were non-attendees. The average result on the final exam was significantly higher among the attendees (6.1 ± 1.2) in comparison with non-attendees (4.9 ± 1.3-p = 0.015). The results demonstrate that an interest group proved to be feasible as a source of complementary information to undergraduate medical students and a valid alternative to circumvent the educational deficits.

Effects of Progesterone on Preclinical Animal Models of Traumatic Brain Injury: Systematic Review and Meta-analysis.

Since the publication of two phase III clinical trials not supporting the use of progesterone in patients with traumatic brain injury (TBI), several possible explanations have been postulated, including limitations in the analysis of results from preclinical evidence. Therefore, to address this question, a systematic review and meta-analysis was performed to evaluate the effects of progesterone as a neuroprotective agent in preclinical animal models of TBI. A total of 48 studies were included for review: 29 evaluated brain edema, 21 evaluated lesion size, and 0 studies reported the survival rate. In the meta-analysis, it was found that progesterone reduced brain edema (effect size - 1.73 [- 2.02, - 1.44], p < 0.0001) and lesion volume (effect size - 0.40 [- 0.65, - 0.14], p = 0.002). Lack of details in the studies hindered the assessment of risk of bias (through the SYRCLE tool). A funnel plot asymmetry was detected, suggesting a possible publication bias. In conclusion, preclinical studies show that progesterone has an anti-edema effect in animal models of TBI, decreasing lesion volume or increasing remaining tissue. However, more studies are needed using assessing methods with lower risk of histological artifacts.

The prevalence and severity of insomnia symptoms during COVID-19: A global systematic review and individual participant data meta-analysis.

INTRODUCTION: There have been no previous meta-analytic studies that have looked at the prevalence of insomnia symptoms in different COVID-19 groups using a single assessment instrument to evaluate insomnia symptoms while maintaining data homogeneity. The current review's associated goal is to undertake an individual participant data (IPD) analysis to further investigate past meta-analyses, a method that has been shown to be more robust than standard meta-analyses. MEETHODS: Only studies that used the Insomnia Severity Index (ISI) to assess insomnia are used in this analysis. The IPDMA was performed and registered in PROSPERO in compliance with the PRISMA IPD Statement (CRD42021275817). From November 2019 to August 2021, researchers explored seventeen databases and six preprint services for relevant studies. RESULTS: The pooled estimate of insomnia symptoms (subthreshold and clinically significant) was 52.57%. An estimated 16.66% of the population suffered from clinically significant insomnia, of which 13.75% suffered from moderate insomnia, and 2.50% suffered from severe insomnia. The different populations' grouping had no statistically significant differences in the prevalence of insomnia symptoms. Insomnia symptoms did not appear to be associated with age or sex. CONCLUSION: Our findings imply that the COVID-19 pandemic is linked to a significant rise in subthreshold insomnia symptoms, but not to moderate or severe insomnia. Educating people from all walks of life about the importance of sleep and the risk of acquiring insomnia symptoms during this or future pandemics should be a top concern.

Effects of Obstructive Sleep Apnea on SARS-CoV-2 Antibody Response After Vaccination Against COVID-19 in Older Adults.

Introduction: Previous studies have linked sleep disturbances (including sleep deprivation and obstructive sleep apnea) to an impairment in immune response after vaccination for several diseases, although it has not yet been tested for COVID-19. This study sought to evaluate the effects of obstructive sleep apnea on anti-SARS-CoV-2 IgG levels after vaccination against COVID-19 among older adults. Methods: The study was based on a convenience sample of inpatients who underwent full night type-I polysomnography. Inclusion criteria included being ≥60 years with full COVID-19 vaccination schedule. Exclusion criteria included previous COVID-19 diagnosis (assessed via self-report), less than 15 days between last dose and IgG testing, self-report of continuous positive air pressure (CPAP) use in the last three months, having undergone CPAP or split-night polysomnography, or incomplete/invalid data. Results: Out of 122 included patients (no/mild OSA: 35; moderate: 31; severe: 56), 9.8% were considered seronegative for the IgG anti-SARS-CoV-2 test (IgG count<50.0 AU/mL), and the median IgG levels for the whole sample was 273 AU/mL (IQR: 744), with no statistically significant differences among OSA severity groups. There was neither association between OSA severity and IgG serostatus nor correlation between IgG levels and apnea-hypopnea index. A linear regression model to predict IgG levels was built, produced an R2 value of 0.066 and the only significant predictor was time from vaccination to testing; while OSA severity was considered non-significant. Discussion: Our results demonstrate that the severity of OSA is not correlated with a decrease in anti-SARS-CoV-2 IgG levels among older adults, and that the efficiency of COVID-19 vaccinations are not reduced from mild to severe OSA.