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MedRxiv : the Preprint Server For... Apr 2024Understanding the function of sleep requires studying the dynamics of brain activity across whole-night sleep and their transitions. However, current gold standard...
Understanding the function of sleep requires studying the dynamics of brain activity across whole-night sleep and their transitions. However, current gold standard polysomnography (PSG) has limited spatial resolution to track brain activity. Additionally, previous fMRI studies were too short to capture full sleep stages and their cycling. To study whole-brain dynamics and transitions across whole-night sleep, we used an unsupervised learning approach, the Hidden Markov model (HMM), on two-night, 16-hour fMRI recordings of 12 non-sleep-deprived participants who reached all PSG-based sleep stages. This method identified 21 recurring brain states and their transition probabilities, beyond PSG-defined sleep stages. The HMM trained on one night accurately predicted the other, demonstrating unprecedented reproducibility. We also found functionally relevant subdivisions within rapid eye movement (REM) and within non-REM 2 stages. This study provides new insights into brain dynamics and transitions during sleep, aiding our understanding of sleep disorders that impact sleep transitions.
PubMed: 38903093
DOI: 10.1101/2024.04.24.24306208 -
Computers in Biology and Medicine Jun 2024Sleep apnea is a common sleep disorder. The availability of an easy-to-use sleep apnea predictor would provide a public health benefit by promoting early diagnosis and...
Sleep apnea is a common sleep disorder. The availability of an easy-to-use sleep apnea predictor would provide a public health benefit by promoting early diagnosis and treatment. Our goal was to develop a prediction tool that used commonly available variables and was accessible to the public through a web site. Using data from polysomnography (PSG) studies that measured the apnea-hypopnea index (AHI), we built a machine learning tool to predict the presence of moderate to severe obstructive sleep apnea (OSA) (defined as AHI ≥15). Our tool employs only seven widely available predictor variables: age, sex, weight, height, pulse oxygen saturation, heart rate and respiratory rate. As a preliminary step, we used 16,958 PSG studies to examine eight machine learning algorithms via five-fold cross validation and determined that XGBoost exhibited superior predictive performance. We then refined the XGBoost predictor by randomly partitioning the data into a training and a test set (13,566 and 3392 PSGs, respectively) and repeatedly subsampling from the training set to construct 1000 training subsets. We evaluated each of the resulting 1000 XGBoost models on the single set-aside test set. The resulting classification tool correctly identified 72.5 % of those with moderate to severe OSA as having the condition (sensitivity) and 62.8 % of those without moderate to-severe OSA as not having it (specificity); overall accuracy was 66 %. We developed a user-friendly publicly available website (https://manticore.niehs.nih.gov/OSApredictor). We hope that our easy-to-use tool will serve as a screening vehicle that enables more patients to be clinically diagnosed and treated for OSA.
PubMed: 38901189
DOI: 10.1016/j.compbiomed.2024.108777 -
Clinical and Experimental... Jun 2024Supine sleep position and rapid eye movement (REM) stage are widely known to aggravate the severity of obstructive sleep apnea (OSA). In general, position-dependent OSA...
OBJECTIVE
Supine sleep position and rapid eye movement (REM) stage are widely known to aggravate the severity of obstructive sleep apnea (OSA). In general, position-dependent OSA is defined as an apnea-hypopnea index (AHI) at least twice as high in the supine position as in other sleep positions, but it can be misdiagnosed if a certain sleep stage, REM or NREM, is dominant in a specific sleep position. In this study, we investigated the influences of the sleep stages on positional dependency.
METHODS
The polysomnographic data from 111 OSA patients aged ≥ 18 years (AHI > five events/hour) who slept in both supine and non-supine positions (each ≥ 5% of the total sleep time) were retrospectively analyzed. The overall ratio of non-supine AHI/supine AHI (NS/S AHI ratio) during the entire sleep was compared between specific sleep stages, i.e., REM or NREM sleep. Additionally, the weighted NS/S AHI ratio reflecting the proportion of each sleep time was created and compared with the original NS/S AHI ratio.
RESULTS
The mean value of the NS/S AHI ratio did not differ between the entire sleep and the specific sleep stages. However, those ratios in the individual patients showed poor agreement of the NS/S AHI ratios between the entire sleep and the specific sleep stages. The weighted NS/S AHI ratio also demonstrated poor agreement with the original NS/S AHI ratio, mainly due to the discrepancy in mild to moderate OSA patients.
CONCLUSION
The weighted NS/S AHI ratio might help assess precise positional dependency.
PubMed: 38898811
DOI: 10.21053/ceo.2023.00037 -
BMC Psychiatry Jun 2024Tinnitus affects approximately 740 million adults globally, involving hearing, emotion, and sleep systems. However, studies using polysomnography and pure-tone...
BACKGROUND
Tinnitus affects approximately 740 million adults globally, involving hearing, emotion, and sleep systems. However, studies using polysomnography and pure-tone audiometry (PTA) are limited. We aimed to assess the correlation between tinnitus and hearing, sleep quality, characteristics, and depression using polysomnography and PTA.
METHODS
In this cross-sectional study, we divided participants into tinnitus and non-tinnitus groups. We included 100 outpatients (65 with tinnitus, 35 without) from a medical center in Taiwan, who underwent polysomnography and completed rating scales including the Patient Health Questionnaire-9 (PHQ-9), Chinese version of the Pittsburgh Sleep Quality Index (PSQI), and Chinese-Mandarin version of the Tinnitus Handicap Inventory (THI-CM). We analyzed correlations, conducted group comparisons, assessed factors related to THI-CM scores, constructed ROC curves to predict depression in the tinnitus group, and performed multinomial and logistic regression to explore associations.
RESULTS
Descriptive statistics identified a cohort with mean age 53.9 ± 12.80 years, 63% exhibited PHQ-9 scores ≥ 10, and 66% had Apnea-Hypopnea Index (AHI) > 5. The ratio of rapid eye movement and deep sleep to stage 1 + 2 sleep was relatively low and non-significant. Likewise, leg movements was higher in the tinnitus group but not statistically significant. In the tinnitus group, 63.08% had depression, and 81.54% had AHI > 5. Univariate logistic regression linked tinnitus to AHI > 5 (Odds ratio (OR) 2.67, p = 0.026) and male sex (OR 2.49, p = 0.034). A moderate positive correlation was found between the THI-CM score and PHQ-9 score (rs = 0.50, p < 0.001). Further adjustment for obstructive sleep apnea showed associations between PHQ-9 (total score) or depression and THI-CM Grade 3-5 (OR = 1.28; OR = 8.68). Single- and multifactor regression analyses highlighted significant associations of PSQI scores > 13 (OR 7.06, p = 0.018) and THI-CM scores > 47 (OR 7.43, p = 0.002) with depression.
CONCLUSIONS
Our study recruited tinnitus participants with slight or mild hearing loss and mild tinnitus handicap. Depression was identified as a predominant factor in tinnitus-related handicap. The mild tinnitus handicap in tinnitus participants may explain the lack of significant differences in depression, sleep quality, and polysomnographic sleep characteristics between tinnitus and non-tinnitus groups. Further extensive and prospective studies are needed to elucidate the complex links among depression, sleep, and tinnitus.
Topics: Humans; Male; Female; Tinnitus; Middle Aged; Polysomnography; Cross-Sectional Studies; Audiometry, Pure-Tone; Adult; Sleep Quality; Aged; Taiwan; Depression
PubMed: 38898451
DOI: 10.1186/s12888-024-05912-y -
BMJ Paediatrics Open Jun 2024Awareness of the need for early identification and treatment of sleep disordered breathing (SDB) in neonates is increasing but is challenging. Unrecognised SDB can have...
OBJECTIVE
Awareness of the need for early identification and treatment of sleep disordered breathing (SDB) in neonates is increasing but is challenging. Unrecognised SDB can have negative neurodevelopmental consequences. Our study aims to describe the clinical profile, risk factors, diagnostic modalities and interventions that can be used to manage neonates with SDB to facilitate early recognition and improved management.
METHODS
A single-centre retrospective study of neonates referred for assessment of suspected SDB to a tertiary newborn intensive care unit in New South Wales Australia over a 2-year period. Electronic records were reviewed. Outcome measures included demographic data, clinical characteristics, comorbidities, reason for referral, polysomnography (PSG) data, interventions targeted to treat SDB and hospital outcome. Descriptive analysis was performed and reported.
RESULTS
Eighty neonates were included. Increased work of breathing, or apnoea with oxygen desaturation being the most common reasons (46% and 31%, respectively) for referral. Most neonates had significant comorbidities requiring involvement of multiple specialists (mean 3.3) in management. The majority had moderate to severe SDB based on PSG parameters of very high mean apnoea-hypopnoea index (62.5/hour) with a mean obstructive apnoea index (38.7/hour). Ten per cent of patients required airway surgery. The majority of neonates (70%) were discharged home on non-invasive ventilation.
CONCLUSION
SDB is a serious problem in high-risk neonates and it is associated with significant multisystem comorbidities necessitating a multidisciplinary team approach to optimise management. This study shows that PSG is useful in neonates to diagnose and guide management of SDB.
Topics: Humans; Retrospective Studies; Infant, Newborn; Sleep Apnea Syndromes; Male; Female; Comorbidity; Polysomnography; New South Wales; Risk Factors; Intensive Care Units, Neonatal
PubMed: 38897623
DOI: 10.1136/bmjpo-2024-002639 -
Sensors (Basel, Switzerland) May 2024Vital sign monitoring is dominated by precise but costly contact-based sensors. Contactless devices such as radars provide a promising alternative. In this article, the...
Vital sign monitoring is dominated by precise but costly contact-based sensors. Contactless devices such as radars provide a promising alternative. In this article, the effects of lateral radar positions on breathing and heartbeat extraction are evaluated based on a sleep study. A lateral radar position is a radar placement from which multiple human body zones are mapped onto different radar range sections. These body zones can be used to extract breathing and heartbeat motions independently from one another via these different range sections. Radars were positioned above the bed as a conventional approach and on a bedside table as well as at the foot end of the bed as lateral positions. These positions were evaluated based on six nights of sleep collected from healthy volunteers with polysomnography (PSG) as a reference system. For breathing extraction, comparable results were observed for all three radar positions. For heartbeat extraction, a higher level of agreement between the radar foot end position and the PSG was found. An example of the distinction between thoracic and abdominal breathing using a lateral radar position is shown. Lateral radar positions could lead to a more detailed analysis of movements along the body, with the potential for diagnostic applications.
Topics: Humans; Radar; Vital Signs; Monitoring, Physiologic; Heart Rate; Respiration; Adult; Male; Polysomnography; Female
PubMed: 38894339
DOI: 10.3390/s24113548 -
Journal of Clinical Medicine May 2024Repetitive episodes of apnea and hypopnea during sleep in patients with obstructive sleep apnea (OSA) are known to increase the risk of atherosclerosis. Underlying...
Repetitive episodes of apnea and hypopnea during sleep in patients with obstructive sleep apnea (OSA) are known to increase the risk of atherosclerosis. Underlying obesity and related disorders, such as insulin resistance, are indirectly related to the development of atherosclerosis. In addition, OSA is independently associated with insulin resistance; however, data regarding this relationship are scarce in Japanese populations. This study aimed to examine the relationship between the severity of OSA and insulin resistance in a Japanese population. We analyzed the data of consecutive patients who were referred for polysomnography under clinical suspicion of developing OSA and who did not have diabetes mellitus or any cardiovascular disease. Multiple regression analyses were performed to determine the relationship between the severity of OSA and insulin resistance. The data from a total of 483 consecutive patients were analyzed. The median apnea-hypopnea index (AHI) was 40.9/h (interquartile range: 26.5, 59.1) and the median homeostasis model assessment for insulin resistance (HOMA-IR) was 2.00 (interquartile range: 1.25, 3.50). Multiple regression analyses revealed that the AHI, the lowest oxyhemoglobin saturation (SO), and the percentage of time spent on SO < 90% were independently correlated with HOMA-IR (an adjusted R-squared value of 0.01278821, = 0.014; an adjusted R-squared value of -0.01481952, = 0.009; and an adjusted R-squared value of 0.018456581, = 0.003, respectively). The severity of OSA is associated with insulin resistance assessed by HOMA-IR in a Japanese population.
PubMed: 38892846
DOI: 10.3390/jcm13113135 -
Respiratory Research Jun 2024Sleep-disordered breathing (SDB) is a major comorbidity in idiopathic pulmonary fibrosis (IPF) and is associated with a poor outcome. There is a lack of knowledge...
Treating sleep-disordered breathing of idiopathic pulmonary fibrosis patients with CPAP and nocturnal oxygen treatment. A pilot study : Sleep-disordered breathing treatment in IPF.
INTRODUCTION
Sleep-disordered breathing (SDB) is a major comorbidity in idiopathic pulmonary fibrosis (IPF) and is associated with a poor outcome. There is a lack of knowledge regarding the impact of SDB treatment on IPF. We assessed at one year: (1) the effect of CPAP and/or nocturnal oxygen therapy on IPF regarding lung function, blood mediators, and quality of life; (2) adherence to SDB treatment and SDB changes.
METHODOLOGY
This is a prospective study of consecutive newly diagnosed IPF patients initiating anti-fibrotic treatment. Lung function, polysomnography, blood tests and quality of life questionnaires were performed at inclusion and after one year. Patients were classified as obstructive sleep apnoea (OSA), central sleep apnoea (CSA), and sleep-sustained hypoxemia (SSH). SDB therapy (CPAP and/or nocturnal oxygen therapy) was initiated if needed.
RESULTS
Fifty patients were enrolled (36% had OSA, 22% CSA, and 12% SSH). CPAP was started in 54% of patients and nocturnal oxygen therapy in 16%. At one-year, polysomnography found improved parameters, though 17% of patients had to add nocturnal oxygen therapy or CPAP, while 33% presented SDB onset at this second polysomnography. CPAP compliance at one year was 6.74 h/night (SD 0.74). After one year, matrix metalloproteinase-1 decreased in OSA and CSA (p = 0.029; p = 0.027), C-reactive protein in OSA (p = 0.045), and surfactant protein D in CSA group (p = 0.074). There was no significant change in lung function.
CONCLUSIONS
Treatment of SBD with CPAP and NOT can be well tolerated with a high compliance. IPF patients may exhibit SDB progression and require periodic re-assessment. Further studies to evaluate the impact of SDB treatment on lung function and serological mediators are needed.
Topics: Humans; Continuous Positive Airway Pressure; Female; Male; Idiopathic Pulmonary Fibrosis; Pilot Projects; Aged; Prospective Studies; Sleep Apnea Syndromes; Oxygen Inhalation Therapy; Middle Aged; Treatment Outcome; Polysomnography; Quality of Life
PubMed: 38890648
DOI: 10.1186/s12931-024-02871-6 -
Sleep & Breathing = Schlaf & Atmung Jun 2024Obstructive sleep apnea (OSA) is associated with metabolic, cardiovascular, and cerebrovascular comorbidities. Appropriate diagnosis and treatment of OSA might mitigate...
PURPOSE
Obstructive sleep apnea (OSA) is associated with metabolic, cardiovascular, and cerebrovascular comorbidities. Appropriate diagnosis and treatment of OSA might mitigate these comorbidities. This retrospective review sought to assess the impact of sex, age, race, ethnicity, and insurance status on polysomnography (PSG) referral rates.
METHODS
An institutional STOP-Bang database of 299,320 patients was filtered for patients admitted to the hospital with an acute cardiac diagnosis between 2015-2020. A cohort of 4,735 patients were risk stratified by STOP-Bang (SB) score and correlations were made between PSG referrals and demographic and clinical variables (sex, age, race, ethnicity, and insurance status).
RESULTS
Of the 25.3% of the cohort with high SB scores (5-8) only 21.3% were referred for PSG. Age and female sex were negatively associated with sleep study referrals (p < 0.001). No correlation was found between sleep study referral rates and race or ethnicity. No correlation was found between sleep study referrals and insurance provider. Admitting cardiac diagnosis significantly influenced sleep study referrals with diagnoses of arrhythmias and myocardial infarction being associated with an increased rate of PSG referrals compared to heart failure patients (p < 0.002).
CONCLUSIONS
Our study found no significant correlation between PSG referral rates and race, ethnicity, or insurance provider. However, we found low overall rates of PSG referral, with negative correlations between older age and female sex and a high-risk cardiac population. This represents a substantial missed opportunity to identify patients at risk for OSA, obtain a diagnosis, and provider adequate treatment.
PubMed: 38890269
DOI: 10.1007/s11325-024-03051-y -
Respiratory Care Jun 2024Sleep-disordered breathing (SDB) is frequent in patients with spinal-cord injury (SCI). However, SDB is frequently underdiagnosed due to limited access to diagnostic...
BACKGROUND
Sleep-disordered breathing (SDB) is frequent in patients with spinal-cord injury (SCI). However, SDB is frequently underdiagnosed due to limited access to diagnostic testing and knowledge about the condition. Moreover, SDB heterogeneity (sleep apnea, obstructive sleep apnea or central sleep apnea and nocturnal alveolar hypoventilation) implies complex evaluation of both nocturnal respiratory effort and hypercapnia. The aim of this study was to compare different screening strategies for an SDB diagnosis in patients with SCI.
METHODS
This was a retrospective analysis of data from subjects with SCI followed up in a tertiary-care rehabilitation center with a specialized sleep unit. Subjective (questionnaires) and objective data (polysomnography [PSG]), S extracted from the PSG, morning blood gases, and nocturnal transcutaneous CO (P ) were collected and analyzed. A retrospective comparison of different strategies for SDB screening was carried out. Each strategy was compared (alone and in combination) with the standard of care for sleep apnea (PSG) and nocturnal alveolar hypoventilation (P ) diagnosis. The performance of the usual cutoff and visual analysis was studied.
RESULTS
Among 190 subjects with SCI who underwent a full night's PSG, data were available for 104 questionnaires and 162 with oximetry. Nocturnal alveolar hypoventilation was screened by P and blood gases in 52 subjects with SCI. Questionnaires (the modified Screening for Obstructive Sleep Apnea in Tetraplegia and the Epworth Sleepiness Scale) had poor performance for identifying sleep apnea and did not identify nocturnal alveolar hypoventilation. S (oxygen desaturation index score ≥ 13) and visual analysis of S were good at identifying sleep apnea but insufficient to identify nocturnal alveolar hypoventilation. Diurnal blood gases were poor predictors of nocturnal alveolar hypoventilation.
CONCLUSIONS
Questionnaires were of limited use in subjects with SCI, but the oxygen desaturation index derived from oximetry performed well for sleep apnea screening. Both diurnal blood gases and oximetry visual analysis were insufficient for nocturnal alveolar hypoventilation screening. P monitoring should be mandatory and ideally combined with PSG given the heterogeneity of SDB phenotypes and associated sleep comorbidities of patients with SCI.
PubMed: 38889927
DOI: 10.4187/respcare.11726