Sleep Center Research Articles

FlexSleepTransformer: a transformer-based sleep staging model with flexible input channel configurations

Clinical sleep diagnosis traditionally relies on polysomnography (PSG) and expert manual classification of sleep stages. Recent advancements in deep learning have shown promise in automating sleep stage classification using a single PSG channel. However, variations in PSG acquisition devices and environments mean that the number of PSG channels can differ across sleep centers. To integrate a sleep staging method into clinical practice effectively, it must accommodate a flexible number of PSG channels. In this paper, we proposed FlexSleepTransformer, a transformer-based model designed to handle varying number of input channels, making it adaptable to diverse sleep staging datasets. We evaluated FlexSleepTransformer using two distinct datasets: the public SleepEDF-78 dataset and the local SleepUHS dataset. Notably, FlexSleepTransformer is the first model capable of simultaneously training on datasets with differing number of PSG channels. Our experiments showed that FlexSleepTransformer trained on both datasets together achieved 98% of the accuracy compared to models trained on each dataset individually. Furthermore, it outperformed models trained exclusively on one dataset when tested on the other dataset. Additionally, FlexSleepTransformer surpassed state-of-the-art CNN and RNN-based models on both datasets. Due to its adaptability with varying channels numbers, FlexSleepTransformer holds significant potential for clinical adoption, especially when trained with data from a wide range of sleep centers.

Do pregnant women with restless legs syndrome experience better sleep with physical activity?

Pregnant women benefit greatly from exercise due to its powerful impact on maternal and perinatal outcomes. The purpose of our study was to assess whether exercise improves objective sleep quality in pregnant women suffering from restless legs syndrome. This cross-sectional study is based on data from a large, naturalistic, consecutive cohort study in pregnant women recruited by four sleep centres, in Bologna, Milan and Turin (Italy), and Lugano (Switzerland), named the Life-ON study. Objective sleep parameters of 316 pregnant women were measured using polysomnographic recordings during the second trimester of pregnancy, and a self-reported assessment was used to evaluate physical activity. Pregnant women with restless legs syndrome (n = 91) who engaged in physical activity (n = 28) experienced better sleep efficiency (84.20% versus 82.10%, p = 0.01), less stage 1 sleep (10.50% versus 11.40%, p = 0.04) and wake after sleep onset (52.20 min versus 76.40 min, p ≤ 0.001), as well as reduced periodic leg movements during sleep (5.50 per hr versus 16.40 per hr, p < 0.001) when compared with the sedentary restless legs syndrome group (n = 63). Sleep structure was also better conserved in physically active pregnant women without restless legs syndrome compared with the inactive restless legs syndrome negative group. Overall, this study provides further evidence of the benefits of physical activity in pregnant women by illustrating its positive impact on sleep structure.

Treated obstructive sleep apnoea and incident arrhythmias

Abstract Background Obstructive sleep apnoea (OSA) is prevalent in approximately 15% of western populations. Cardiovascular disease and arrhythmia are extremely common in this group with significant morbidity overlap. Whilst treatment of OSA with continuous positive airways pressure (CPAP) appears to reduce hypertension, bradycardia and recurrence of atrial fibrillation (AF), large randomised control trials and meta-analyses do not demonstrate a significant reduction of incident tachyarrhythmias such as atrial fibrillation or sudden cardiac death. Some smaller studies suggest that AF may have up to 20% incidence. Analysis of these studies suggest that there may be significant heterogeneity in both CPAP usage and OSA phenotype, confounding the results. Furthermore, standard arrhythmia detection often underestimates paroxysmal arrhythmias. This on-going trial investigates a treated OSA population using CPAP monitoring and implantable loop recorders (ILR). Purpose This study aims to identify the incidence of arrhythmia in a treated OSA population with comprehensive arrhythmia monitoring and CPAP usage. It also explores the mechanisms linking OSA and arrhythmia such as heart rate variability and turbulence and cardiac biomarkers in order to identify at risk sub populations. Methods Continuous moderate-to-severe OSA patients were recruited from a major UK sleep centre after ECG and medical history confirmed the absence of arrhythmia. Each patient was then randomised to receive either standard-care or standard-care with an ILR with 24-hour heart rate variability/turbulence measurements, echocardiography (where possible) and cardiac biomarkers at baseline and 12 months. All patients had remote CPAP usage monitoring (where possible). The trial ended at 36 months after enrolment. Results 200 patients were recruited to the trial. Current mean average follow-up is 28 months in this on-going trial. Mean age and apnoea hypopnea index at enrolment was 53 years and 43.8 respectively. To date we have diagnosed atrial fibrillation in 15% of the ILR group compared to 2% in the standard care group. Other arrhythmias detected in the ILR group include two with supraventricular tachycardia and 2 with significant pauses but not requiring further treatment. Final analysis of arrhythmia incidence with CPAP usage and heart rate variability/turbulence, and cardiac biomarkers is ongoing with final results due by the time of final submission. Conclusion Arrhythmias, particularly AF, are highly incident in OSA despite CPAP treatment. This study may determine if heterogenous CPAP usage confounds the above observation and whether there may be predictors of arrhythmia that may indicate a need for arrhythmia screening in the OSA population.

Clinical predictors of moderate-to-severe pediatric obstructive sleep apnea.

Children with moderate-to-severe obstructive sleep apnea (OSA) require specific management. However, the risk factors associated with this level of severity in pediatric OSA remain poorly defined. This study aimed to identify clinical predictors of moderate-to-severe pediatric OSA. This retrospective study enrolled children aged 1-18 years who underwent respiratory polygraphy or nocturnal oximetry between January 2013 and December 2017. Patient history, demographics, and sleep study data were analyzed. Logistic regression analysis was conducted to assess risk factors associated with moderate-to-severe pediatric OSA. The STROBE checklist was followed in reporting this research. Among 818 children with a median age of 5 years (IQR: 3, 9), 69.4% were male, and 96.7% were diagnosed with OSA. Of those diagnosed, 542 (66.3%) had moderate-to-severe cases. Independent predictors of moderate-to-severe OSA, with their adjusted odds ratios (95% CI), included: age 1-5 years; 6.16 (3.98-9.53), obesity; 2.08 (1.35-3.19), adenotonsillar hypertrophy; 1.58 (1.05-2.36), frequent snoring (>5 nights/week); 6.86 (4.40-10.67), stopped breathing during sleep; 2.34 (1.50-3.63), awakening during sleep; 2.04 (1.32-3.12), and excessive daytime somnolence; 2.10 (1.28-3.43). Children referred to a sleep center demonstrated an increased risk of being diagnosed with moderate-to-severe OSA. Key clinical predictors of moderate-to-severe OSA included age 1-5 years, frequent snoring, episodes of stopped breathing or awakening during sleep, excessive daytime somnolence, obesity, and adenotonsillar hypertrophy. Prioritizing early sleep investigations and appropriate management for children exhibiting these predictors may enhance clinical outcomes and mitigate the risk of long-term complications.

Study on cerebral oxygen saturation in children with sleep-disordered breathing.

To explore the association between the severity of sleep-disordered breathing, different types of respiratory events, peripheral oxygen saturation (SpO2), age and sleep stage on cerebral oxygen saturation (rSO2) in children. We enrolled children aged 4-14 years who were treated for snoring or mouth breathing at the Sleep Center of Beijing Children's Hospital, from February 2022 to July 2022. All children completed polysomnography, and SpO2, rSO2, and heart rate (HR) were recorded synchronously. A total of 70 children were included, including 16 (22.9%) with primary snoring, 38 (54.3%) with mild obstructive sleep apnea (OSA), and 16 (22.9%) with moderate-to-severe OSA. There were no significant differences in the mean rSO2 or minimum rSO2 among the primary snoring, mild OSA, and moderate-to-severe OSA groups (all p > 0.05). A total of 1119 respiratory events were included in the analysis. Regardless of the type of respiratory event, rSO2 and HR changes occur prior to fluctuations in SpO2. A mixed-effects model showed that ΔrSO2 was positively correlated with ΔSpO2, duration of respiratory event, mixed and obstructive apnea, central apnea, while negatively correlated with age and rapid eye movement (REM) sleep stage (all p < 0.05). Larger rSO2 fluctuations were impacted by a greater ΔSpO2, longer duration of respiratory events, younger age, apnea-related respiratory events and non-REM sleep stage. Thus, sleep disordered breathing in younger children warrants more attention. More research is needed to determine whether REM sleep has special protective effects on rSO2.

Probabilistic Sleep Staging in MSLTs across Hypersomnia Disorders.

This study aimed to identify novel markers of narcolepsy type 1 (NT1) using between-nap opportunity periods ('Lights On') and in-nap opportunity periods ('Lights Off') features of Multiple Sleep Latency Test (MSLT) recordings. We hypothesized that NT1 could be identified both from sleep-wake instability and patterns of sleepiness during wakefulness. Further, we explored if MSLTs from NT1 and narcolepsy type 2 (NT2) patients could be distinguished despite having the same diagnostic thresholds. We analyzed 'Lights On' and 'Lights Off' periods of the MSLT, extracting 163 features describing sleepiness, microsleep, and sleep stage mixing using data from 177 patients with NT1, NT2, Idiopathic Hypersomnia (IH), and Subjective Hypersomnia (sH) from three sleep centers. These features were based on automated probabilistic sleep staging, also denoted as hypnodensities, using U-Sleep. Hypersomnias were differentiated using either or both features from 'Lights On' and 'Lights Off'. Patients with NT1 could be distinguished from NT2, IH, and sH using features solely from 'Lights On' periods with a sensitivity of 0.76 and specificity of 0.71. When using features from all periods of the MSLT, NT1 was distinguished from NT2 alone with a sensitivity of 0.77 and a specificity of 0.84. The findings of this study demonstrate microsleeps and sleep stage mixing as potential markers of the sleep attacks and unstable sleep-wake states common in NT1. Further, NT1 and NT2 could be frequently distinguished using 'Lights Off' features.

Polysomnographic and clinical characteristics of sleep apnea headache patients.

Sleep apnea headache can be defined as a persistent, widespread, throbbing headache that occurs recurrently, is not accompanied by any additional symptoms after waking up, and usually resolves within four hours. Diagnosis of the condition requires confirmation through polysomnography with an apnea-hypopnea index of at least 5, indicating the presence of obstructive sleep apnea syndrome (OSAS). While sleep apnea headaches are common in 10-15% of individuals with OSAS, morning headaches are experienced by 5% of this population. The aim of this study is to examine both polysomnographic and clinical features associated with sleep apnea headache in individuals confirmed to have OSAS by polysomnography. The study was conducted in the sleep center of University of Health Science, Erenköy Mental and Nervous Disease Training and Research Hospital. We have examined the clinical and polysomnographic data of the patients with sleep apnea headache (SAH) diagnosed according to IHS-3 criteria retrospectively and grouped the patients as mild, moderate and severe OSAS. Patients with morning headache except sleep apnea headache and under PAP titration treatment were excluded. The differences between the sleep macro structures of patients with (WSAH) and without sleep apnea headache (WOSAH) were examined. The WSAH group consisted of 384 participants and the control group (WOSAH) consisted of 294 participants The mean age was 46.29 ± 12.18 and 45.08 ± 12.62 years, respectively. Patients in the WSAH group had significantly higher scores on the Epworth Sleepiness Scale (ESS) (p = 0.004) and higher periodic limb movement index (PLMI) (p = 0.014) compared to the WOSAH group. WSAH patients exhibited shorter wake times after sleep onset (WASO) and lower scores on the sleep quality index, in contrast to WOSAH patients. Additionally, within the WSAH group, there was a negative correlation between age and several sleep parameters, including total sleep parameters. A positive correlation was observed between sleep duration (p = 0.009), waking up after sleep (p = 0.043), sleep efficiency (p = 0.001) and apnea-hypopnea index (AHI) (p = 0.018). Additionally, ESS scores were positively correlated with AHI and total awake time (p = 0.000 and p = 0.008, respectively), while negatively correlated with stage N3 sleep percentage and mean minimum oxygen level (p = 0.001 and p = 0.020, respectively) in the WSAH group. The causes and possible mechanisms of sleep apnea headache are not fully clarified and the underlying processes are not fully understood. Sleep apnea headaches appear to be related to disturbances in nocturnal sleep. Dysregulation in regions that modulate sleep and nociception may be one possible mechanism.

The Swedish sleep apnea registry (SESAR) cohort – “Real world data” on a national level

IntroductionThe Swedish Sleep Apnea Registry (SESAR) collects clinical data from individual obstructive sleep apnea (OSA) patients since 2010. SESAR has recently been integrated with additional national healthcare data. The current analysis presents the SESAR structure and representative clinical data of a national sleep apnea cohort. MethodsClinical data from unselected patients with a diagnosis of OSA are submitted to the SESAR registry. 48 sleep centers report data from diagnosis, treatment starts with Continuous Positive Airway Pressure (CPAP), oral devices (OD), and Upper Airway Surgery (UAS). Data from follow-up are included. SESAR is linked to mandatory national healthcare data (mortality, comorbidities, procedures, prescriptions) and diagnosis-specific quality registries (e.g. stroke, heart failure, diabetes) within the DISCOVERY project. Results83,404 OSA patients have been reported during the diagnostic workup (age 55.4 ± 14.1 years, BMI 30.8 ± 6.5 kg/m2, AHI 25.8 ± 21.6n/h, respectively). At least one cardiometabolic and respiratory comorbidity is recognized in 57 % of female and 53 % of male OSA patients with a linear increase across OSA severity. In 54,468, 7,797, and 390 patients, start of CPAP, OD or UAS treatment is reported, respectively. OD patients have 4 units lower BMI and 10 units lower AHI compared to patients started on CPAP. UAS patients are characterized by 10 years lower age. The degree of daytime sleepiness is comparable between treatment groups with mean Epworth Sleepiness Scale Scores between 9 and 10. ConclusionSESAR is introduced as a large national registry of OSA patients. SESAR provides a useful tool to highlight OSA management and to perform relevant outcome research.

Validation of the International REM Sleep Behavior Disorder Study Group Symptoms Severity Scale (IRBD-SSS): a new tool to assess RBD clinical severity.

Currently, no standard scale has been validated to assess overall severity of RBD symptoms in the home environment. We aimed to evaluate the psychometric properties of the International RBD Severity Scale (IRBD-SSS), a new tool designed by the International RBD Study Group. Two versions of the IRBD-SSS were created, one for the patient (IRBD-SSS-PT) and another for the bedpartner (IRBD-SSS-BP), both consisting of 3 components, namely vocalizations, body movements and injury, with a fourth component (patient version only) evaluating dream content. To score each dimension, the frequency and severity/impact of behaviors during the previous month are multiplied. Psychometric properties of the IRBD-SSS were assessed, including reproducibility. A total of 188 subjects including n = 132 RBD patients (n = 94 isolated RBD and n = 38 symptomatic RBD) and n = 52 bedpartners were enrolled from eight Sleep centers across France and Italy. Participants completed the scale at baseline and after one week. Acceptability of the scale was excellent in patients (97%) and bedpartners (98%). Internal consistency was acceptable for IRBD-SSS-PT (Cronbach α = 0.75) while slightly low for IRBD-SSS-BP (Cronbach α = 0.49). Concurrent validity was good for both patient (r = 0.70;p < 0.001, see Figure) and bedpartner (r = 0.69;p < 0.001) IRBD-SSS. Reproducibility was high for IRBD-SSS-PT (Lin's coefficient of agreement = 0.85 [0.81;0.90]) and good for the IRBD-SSS-BP (0.79 [0.68;0.90] (p < 0.001). Both the patient and bedpartner versions of the IRBD-SSS showed excellent acceptability, acceptable internal consistency, good external validity and high reproducibility. IRBD-SSS is a useful tool to test the severity of RBD symptoms in clinical settings and clinical trials. NCT04071899.

Orthodontic perspectives of obstructive sleep apnea

OSA is defined as a condition in which there is repetitive partial or complete collapse of the pharynx during sleep. An apnea is defined as an almost complete (at least 90%) cessation of airflow, and hypopnea is defined as a reduction in nasal pressure amplitude of at least 50% and/ or a reduction in thoracoabdominal movement of 50% or more for a minimum of 10 seconds. Often, patients first seek an otorhinolaryngologic (ENT) evaluation rather than presenting to a sleep center. Normal sleep involves air passing through and going directly down to the lungs. With an obstructed airway, the structures in the back of the throat (the tongue, the tonsils, and/or adenoids) occlude the airway due to an inadequate motor tone of the tongue and/or airway dilator muscles, and thus, prevent the air from passing. The aetiology is multifactorial, and the main risk factors in children include adenotonsillar hypertrophy, obesity, neuromuscular disorders and craniofacial anomalies. Adenotonsillar hypertrophy is the most commonly reported aetiological factor. Therefore, the treatment of choice for paediatric OSA is adenotonsillectomy. In adulthood, the use of oral appliances is a treatment option in the management of OSA

Central Sleep Apnea in Children-10 Years Experience at a Tertiary Sleep Laboratory.

Central sleep apnea (CSA) is a rare condition in children; however, it can cause significant morbidity if not diagnosed early. We aimed to increase the knowledge about CSA in children by describing the clinical characteristics of children diagnosed with CSA at our sleep center. We retrospectively reviewed 1263 polysomnographies (PSG) performed between 2012 and 2023 at our tertiary sleep center and evaluated the clinical characteristics of the patients with CSA. Underlying diseases, clinical symptoms, sleep parameters, and short-term management of the patients were recorded. Of the 1263 patients aged between 1 month and 18 years, 122 (9.65%) had CSA, with 54.9 % (n = 67) of them being female. Only 56.6% (n = 69) of the patients' parents had reported a symptom indicating sleep-disordered breathing. The most common underlying disease was genetic, including Down and Prader-Willi syndromes, followed by neurological diseases . Obstructive sleep apnea was detected in addition to CSA in 103 of the patients (84.4%). Bi-level positive airway pressure with a backup rate was the most common treatment modality. While CSA is a rare clinical condition in children, it occurs more commonly in those with an underlying disease. Awareness of the disease and timely referral of the patients for sleep studies are critical to prevent long-term sequelae.

Overnight Sleep Staging Using Chest-Worn Accelerometry.

Overnight sleep staging is an important part of the diagnosis of various sleep disorders. Polysomnography is the gold standard for sleep staging, but less-obtrusive sensing modalities are of emerging interest. Here, we developed and validated an algorithm to perform "proxy" sleep staging using cardiac and respiratory signals derived from a chest-worn accelerometer. We collected data in two sleep centers, using a chest-worn accelerometer in combination with full PSG. A total of 323 participants were analyzed, aged 13-83 years, with BMI 18-47 kg/m2. We derived cardiac and respiratory features from the accelerometer and then applied a previously developed method for automatic cardio-respiratory sleep staging. We compared the estimated sleep stages against those derived from PSG and determined performance. Epoch-by-epoch agreement with four-class scoring (Wake, REM, N1+N2, N3) reached a Cohen's kappa coefficient of agreement of 0.68 and an accuracy of 80.8%. For Wake vs. Sleep classification, an accuracy of 93.3% was obtained, with a sensitivity of 78.7% and a specificity of 96.6%. We showed that cardiorespiratory signals obtained from a chest-worn accelerometer can be used to estimate sleep stages among a population that is diverse in age, BMI, and prevalence of sleep disorders. This opens up the path towards various clinical applications in sleep medicine.

Phase-Amplitude Coupling in Theta and Beta Bands: A Potential Electrophysiological Marker for Obstructive Sleep Apnea.

Phase-amplitude coupling (PAC) between the phase of low-frequency signals and the amplitude of high-frequency activities plays many physiological roles and is involved in the pathological processed of various neurological disorders. However, how low-frequency and high-frequency neural oscillations or information synchronization activities change under chronic central hypoxia in OSA patients and whether these changes are closely associated with OSA remains largely unexplored. This study arm to elucidate the long-term consequences of OSA-related oxygen deprivation on central nervous system function. : We screened 521 patients who were clinically suspected of having OSA at our neurology and sleep centers. Through polysomnography (PSG) and other clinical examinations, 103 patients were ultimately included in the study and classified into mild, moderate, and severe OSA groups based on the severity of hypoxia determined by PSG. We utilized the phase-amplitude coupling (PAC) method to analyze the modulation index (MI) trends between different frequency bands during NREM (N1/N2/N3), REM, and wakefulness stages in OSA patients with varying severity levels. We also examined the correlation between the MI index and OSA hypoxia indices. Apart from reduced N2 sleep duration and increased microarousal index, the sleep architecture remained largely unchanged among OSA patients with varying severity levels. Compared to the mild OSA group, patients with moderate and severe OSA exhibited higher MI values of PAC in the low-frequency theta phase and high-frequency beta amplitude in the frontal and occipital regions during N1 sleep and wakefulness. No significant differences in the MI of phase-amplitude coupling were observed during N2/3 and REM sleep. Moreover, the MI of phase-amplitude coupling in theta and beta bands positively correlated with hypoxia-related indices, including the apnea-hypopnea index (AHI) and oxygenation desaturation index (ODI), and the percentage of oxygen saturation below 90% (SaO2<90%). OSA patients demonstrated increased MI values of theta phase and beta amplitude in the frontal and occipital regions during N1 sleep and wakefulness. This suggests that cortical coupling is prevalent and exhibits sleep-stage-specific patterns in OSA. Theta-beta PAC during N1 and wakefulness was positively correlated with hypoxia-related indices, suggesting a potential relationship between these neural oscillations and OSA severity. The present study provides new insights into the relationship between neural oscillations and respiratory hypoxia in OSA patients.

Associations between self-reported parasomnias and psychiatric illness in 370,000 patients with sleep disorders.

To assess self-reported parasomnias in patients with sleep disorders and explore relationships with psychiatric illness, comorbidities, subjective sleep assessments, and polysomnographic study results. Results from intake questionnaires and polysomnographic assessments, collected from 240 sleep centers across 30 US states between 2004 and 2019, were analyzed retrospectively. Of 540,000 total patients, 371,889 who answered parasomnia-specific questions were included. Patients responding "often" or "always" to parasomnia-specific questions were considered "symptom-positive," whereas a "few times" or "never" were considered "symptom-negative" (controls). The study sample was 54.5% male with mean age 54 years (range, 2-107 years). Frequencies for the different parasomnias were 16.0% for any parasomnia, 8.8% for somniloquy, 6.0% for hypnagogic hallucinations, 4.8% for sleep-related eating disorder, 2.1% for sleep paralysis, and 1.7% for somnambulism. Frequent parasomnias were highly associated with diagnosed depression (odds ratio = 2.72). All parasomnias were associated with being younger and female and with symptoms of depression, anxiety, insomnia, restless legs, pain, medical conditions, fatigue, and sleepiness. Associations with objective sleep metrics showed characteristics of consolidated sleep and differentiated weakly between nonrapid eye movement sleep and rapid eye movement sleep parasomnias. Machine learning accurately classified patients with parasomnia versus controls (balanced accuracies between 71% and 79%). Benzodiazepines, antipsychotics, and opioids increased the odds of experiencing parasomnias, while antihistamines and melatonin reduced the odds. Z-drugs were found to increase the likelihood of a sleep-related eating disorder. Our findings suggest that parasomnias may be clinically relevant, yet understudied, symptoms of depression and anxiety. Further investigation is needed to quantify the nature of multimorbidity, including causality and implications for diagnosis and treatment.

Co-morbid Insomnia and Sleep Apnea (COMISA) in a large sample of Iranian: prevalence and associations in a sleep clinic population.

Sleep apnea (SA) and insomnia (INS) are prevalent sleep disorders among referrals to sleep clinics. People with comorbid insomnia and sleep apnea (COMISA) suffer both disorders simultaneously. The epidemiology of COMISA is not well known in the Middle East including Iran. We hypothesized that COMISA is prevalent in metropolitan sleep clinic cohorts in Iran. The records of patients aged < 95 years referred to sleep disorders centers in four large metropolitan areas including Kermanshah, Tabriz, Shiraz, and Ahvaz were examined. Polysomnography (PSG) was performed in all these patients in specialized centers and the results were scored by a trained technician and interpreted by a sleep specialist. SA was defined as an Apnea-Hypopnea Index (AHI ≥ 5), INS was defined by psychiatrists according to self-report and clinical interviews, and COMISA was defined if both disorders were present. Participants with neither condition were included in as comparator group. One-way ANOVAs, correlation, and linear/logistic regression analyses were used. This study included 1807 patients (Mean age 49.3, SE ± 13.7; 38.8% Female). Comparator, INS, SA and COMISA made up 7.2%, 16%, 50.2% and 26.6% of the sample, respectively. Logistic regression analyses showed that male gender, older age, and increasing neck circumference, but not BMI, were associated with COMISA. Epworth Sleepiness Scale scores were lower in INS (5.39 ± 5.78) compared to the other three groups. COMISA is a prevalent condition in metropolitan sleep centers in Iran among participants referred to sleep centers. The data showed that male gender and age were associated significantly with COMISA.

A Survey Study of the 3D Facial Landmark Detection Techniques Used as a Screening Tool for Diagnosis of the Obstructive Sleep Apnea Syndrome.

Obstructive Sleep Apnea (OSA) is a common disorder affecting both adults and children. It is characterized by repeated episodes of apnea (stopped breathing) and hypopnea (reduced breathing), which result in intermittent hypoxia. We recognize pediatric and adult OSA, and this paper focuses on pediatric OSA. While adults often suffer from daytime sleepiness, children are more likely to develop behavioral abnormalities. Early diagnosis and treatment are important to prevent negative effects on children's development. Without the treatment, children may be at increased risk of developing high blood pressure or other heart problems. The gold standard for OSA diagnosis is the polysomnography (sleep study) PSG performed at a sleep center. Not only is it an expensive procedure, but it can also be very stressful, especially for children. Patients have to stay at the sleep center during the night. Therefore, screening tools are very important. Multiple studies have shown that OSA screening tools can be based on facial anatomical landmarks. Anatomical landmarks are landmarks located at specific anatomical locations. For the purpose of the screening tool, a specific list of anatomical locations needs to be identified. We are presenting a survey study of the automatic identification of these landmarks on 3D scans of the patient's head. We are considering and comparing both knowledge-based and AI-based identification techniques, with a focus on the development of the automatic OSA screening tool.

Sex-specific Age-Related Worsening of Pathological Endotypic Traits in Patients with Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is more prevalent in men and older adults. Few studies have explored variations in pathological endotypic traits by age and sex using a large patient sample, offering insights into the development of the disease. Our study aims to examine how endotype characteristics of obstructive sleep apnea vary across age in different sex. A cross-sectional study was conducted, enrolling 2296 adult patients referred for in-laboratory diagnostic polysomnography at a single sleep center in Taiwan. Among them, 1374 had an apnea-hypopnea index ≥ 5. Using the "Phenotyping Using Polysomnography" method, we estimated four endotypic traits-arousal threshold, upper airway collapsibility, loop gain, and upper airway muscle compensation. Demographic and polysomnographic characteristics were compared between sexes and age groups. Generalized linear regression and generalized additive models were employed to explore the associations of sex and age with endotypic traits. Men with OSA exhibited higher collapsibility and lower compensation than women (difference: 4.32 %eupnea and 4.49 %eupnea, respectively). Younger patients with OSA had a higher prevalence of obesity, more snoring symptoms, and lower loop gain compared to older patients. For men, age was correlated with increased collapsibility, increased loop gain, and decreased arousal threshold after 37 years old. Whereas in women, endotypic traits were not associated with age, except for an increase in loop gain with advancing age. Personalized treatment options for OSA should take into consideration age and sex. Reducing loop gain could be a treatment objective for older patients with OSA.

Triglyceride-glucose index and combined indicators: effective indicators for screening NAFLD in snoring patients

AimsNonalcoholic fatty liver disease (NAFLD) is a common complication in snoring patients, especially in patients with obstructive sleep apnea syndrome (OSA). Triglyceride-glucose (TyG) index was a simple indicator of metabolic status and a surrogate marker of insulin resistance. This study aimed to explore the relationship between NAFLD and TyG index in snoring patients.MethodsA retrospective study was conducted. The successive snoring patients enrolled in the Sleep Center of the First Affiliated Hospital of Fujian Medical University and had abdominal ultrasonography were included. The clinical characteristics of patients in different quartile TyG groups were compared. The relationship of the TyG index and NAFLD were valued via logistic regression models and restricted cubic spline analysis. The value of TyG index in predicting NAFLD was determined by receiver operating characteristic curve (ROC curve).ResultsA total of 463 NAFLD cases were found among the 654 snoring patients. TyG index was a risk factor of NAFLD in snoring patients (OR = 2.38, 95% CI = 1.71–3.36). The risk of NAFLD was much higher in patients with the highest quartile of TyG index (OR = 5.12, 95% CI = 2.85–9.22), compared with the lowest quartile group. Restricted cubic spline (RCS) analysis showed a significant dose-response relationship between TyG index and risk of NAFLD (p for non-linearity < 0.001). A combination of TyG, neck circumference and ESS score presented the acceptable AUC for the detection of NAFLD in snoring patients (0.746, 95% CI 0.701–0.790, p < 0.001).ConclusionThe TyG index was a risk factor of NAFLD in snoring patients. A combination of TyG, neck circumferences and ESS score could act as a convenient and effective indicator for screening NAFLD in snoring patients.

Novel physiologic predictors of positive airway pressure effectiveness (NICEPAP) study: rationale, design and methods.

Continuous positive airway pressure (CPAP) is the primary therapy for obstructive sleep apnea (OSA); however the effectiveness of CPAP remains suboptimal. We describe the Novel PhysIologiC prEdictors of Positive Airway Pressure Effectiveness (NICEPAP) study. Its purpose is to determine whether physiological traits of OSA contribute to CPAP effectiveness. NICEPAP (NCT05067088) is a prospective, observational cohort study conducted at an academic sleep center. Adults newly diagnosed with OSA (n = 267) are assessed for OSA traits of loop gain, arousal threshold, pharyngeal collapsibility, and muscle compensation from baseline polysomnography. We perform a comprehensive assessment of covariates relevant to CPAP adherence, efficacy, and patient-centered outcomes. Participants are followed for 12 months. Primary outcomes include (1) CPAP adherence (hours/night), (2) CPAP efficacy (apneas-hypopneas/hour), and (3) quality of life at six months measured by objective CPAP data and Functional Outcomes of Sleep Questionnaire. Secondary outcomes include sleep quality, sleepiness, insomnia, and neurocognitive function. Data on covariates, including demographics, sleep symptoms, medical history, medications, sleep quality, OSA and treatment self-efficacy, decisional balance, and socio-economic and social and partner support, are collected using validated instruments. The analysis for primary outcomes includes a generalized linear mixed model for an outcome (e.g., CPAP adherence) with OSA traits as exposures followed by the addition of relevant covariates. The findings of the NICEPAP study will inform research aimed to enhance CPAP effectiveness. Understanding the role of physiological OSA traits in CPAP effectiveness is a crucial step toward a precision medicine approach to OSA.

Performing polysomnography in pre-school aged children: challenging parts of the procedure and risk factors for lead intolerance.

Pediatric sleep apnea begins in toddlerhood when sleep is vital for neurocognitive development and rapid somatic growth. As polysomnography (PSG) can be challenging in this age group, this study described the first PSG for children aged 2 to 6 years old in regards to completion and risk-factors for intolerance. Single center chart review in a pediatric-only hospital-based sleep center. Of the 342 children age 2 to 6 years old, 99.5% completed the study and 56% cooperated with the full hook-up; the nasal monitors were the least tolerated. Children who did not achieve a full hook-up slept 0.7h fewer (p = 0.04), woke up more often (p = 0.015), and took 15min longer to fall asleep (p = 0.012). Younger age and having autism were independent risk factors for poor tolerance. The majority of pre-schoolers tolerated their first PSG. Interventional trials to increase PSG success in this population should prepare those under 3-years-old and with sensory processing issues to cooperate with nasal monitors.