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Objective: This longitudinal study investigated potential positive impact of CPAP treatment on brain health in individuals with obstructive sleep Apnea (OSA). To allow this, we aimed to employ sleep electroencephalogram (EEG)-derived brain age index (BAI) to quantify CPAP's impact on brain health and identify individually varying CPAP effects on brain aging using machine learning approaches., Methods: We retrospectively analyzed CPAP-treated (n = 98) and untreated OSA patients (n = 88) with a minimum 12-month follow-up of polysomnography. BAI was calculated by subtracting chronological age from the predicted brain age. To investigate BAI changes before and after CPAP treatment, we compared annual ΔBAI between CPAP-treated and untreated OSA patients. To identify individually varying CPAP effectiveness and factors influencing CPAP effectiveness, machine learning approaches were employed to predict which patient displayed positive outcomes (negative annual ΔBAI) based on their baseline clinical features., Results: CPAP-treated group showed lower annual ΔBAI than untreated (-0.6 ± 2.7 vs. 0.3 ± 2.6 years, p < 0.05). This BAI reduction with CPAP was reproduced independently in the Apnea, Bariatric surgery, and CPAP study cohort. Patients with more severe OSA at baseline displayed more positive annual ΔBAI (=accelerated brain aging) when untreated and displayed more negative annual ΔBAI (=decelerated brain aging) when CPAP-treated. Machine learning models achieved high accuracy (up to 86%) in predicting CPAP outcomes., Interpretation: CPAP treatment can alleviate brain aging in OSA, especially in severe cases. Sleep EEG-derived BAI has potential to assess CPAP's impact on brain health. The study provides insights into CPAP's effects and underscores BAI-based predictive modeling's utility in OSA management., (© 2024 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Background: Obstructive sleep apnoea (OSA) is a common sleep disorder characterized by repetitive episodes of upper airway collapse during sleep associated with arousals with or without oxygen desaturation., Objective: This study aims to assess and analyse the morphological and neurological factors associated with obstructive sleep apnoea using polysomnography study data and two-dimensional cephalometric analysis of airway and skeletal parameters and their correlation in the patients with varying severities of obstructive sleep apnoea., Methods: This study included 892 patients who underwent a complete work up, including a thorough history, clinical examination, standard polysomnography study and 2D cephalometric analysis to diagnose obstructive sleep apnoea. This study divided the participants into two groups based on the AHI score from the PSG study: AHI < 15 and AHI > 15 groups. The groups were further divided into male and female groups to study the prevalence of OSA. The analysis involved 13 cephalometric parameters: Seven linear and six angular measurements. The airway parameters measured in this study were minimum posterior airway space (PAS&#95;min), hyoid bone to the mandibular plane (H&#95;MNP) and soft palate length (SPL). All the subjects in this study underwent a standard overnight polysomnography study at the sleep centre in Samsung Medical Center., Results: A total of 892 adult participants (M: F = 727:165, mean age: 50.6 ± 13.2 years and age range: 18-85 years). AHI >15 group was significantly older with higher BMI, NC and WC compared to the AHI < 15 groups in both male and female groups. There was statistical significance observed in N1, N3, AI, ODI, lowest saturation (%) and apnoea max length between the groups (p < .001). The arousal index (AI), especially the respiratory arousal index was considerably higher in the male group. There were significantly higher values in all the PSG parameters in the male group. In the airway parameters, hyoid bone position and soft palate length showed significant differences (p < .001), whereas the PAS did not show any differences (p = .225) between the AHI <15 and AHI >15 groups. The overall skeletal cephalometric parameters showed no significant differences between the groups, whereas the gonial angle and AB to mandibular plane angle showed significant differences in the female group (p = .028, p = .041 respectively)., Conclusion: The partial correlation of cephalometric parameters with AHI showed a stronger correlation between the H&#95;MNP and AHI in both men and women. The position of the hyoid bone and the soft palate length influences the progression of OSA, especially in male patients. This study found no direct association between the minimum PAS and varying severities of OSA in men and women. We speculate that more than the craniofacial morphological factors such as the sagittal and vertical position of the maxilla and the mandible, the position of the hyoid bone might be more responsible for the severity of OSA., (© 2023 John Wiley & Sons Ltd.)

Background: /Objective: Automatic apnea/hypopnea events classification, crucial for clinical applications, often faces challenges, particularly in hypopnea detection. This study aimed to evaluate the efficiency of a combined approach using nasal respiration flow (RF), peripheral oxygen saturation (SpO2), and ECG signals during polysomnography (PSG) for improved sleep apnea/hypopnea detection and obstructive sleep apnea (OSA) severity screening., Methods: An Xception network was trained using main features from RF, SpO2, and ECG signals obtained during PSG. In addition, we incorporated demographic data for enhanced performance. The detection of apnea/hypopnea events was based on RF and SpO2 feature sets, while the screening and severity categorization of OSA utilized predicted apnea/hypopnea events in conjunction with demographic data., Results: Using RF and SpO2 feature sets, our model achieved an accuracy of 94 % in detecting apnea/hypopnea events. For OSA screening, an exceptional accuracy of 99 % and an AUC of 0.99 were achieved. OSA severity categorization yielded an accuracy of 93 % and an AUC of 0.91, with no misclassification between normal and mild OSA versus moderate and severe OSA. However, classification errors predominantly arose in cases with hypopnea-prevalent participants., Conclusions: The proposed method offers a robust automatic detection system for apnea/hypopnea events, requiring fewer sensors than traditional PSG, and demonstrates exceptional performance. Additionally, the classification algorithms for OSA screening and severity categorization exhibit significant discriminatory capacity., Competing Interests: Declaration of competing interest We know of no conflicts of interest associated with this publication, and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Sleep disorders, such as obstructive sleep apnea (OSA), comorbid insomnia and sleep apnea (COMISA), and insomnia are common and can have serious health consequences. However, accurately diagnosing these conditions can be challenging as a result of the underrecognition of these diseases, the time-intensive nature of sleep monitoring necessary for a proper diagnosis, and patients' hesitancy to undergo demanding and costly overnight polysomnography tests., Objective: We aim to develop a machine learning algorithm that can accurately predict the risk of OSA, COMISA, and insomnia with a simple set of questions, without the need for a polysomnography test., Methods: We applied extreme gradient boosting to the data from 2 medical centers (n=4257 from Samsung Medical Center and n=365 from Ewha Womans University Medical Center Seoul Hospital). Features were selected based on feature importance calculated by the Shapley additive explanations (SHAP) method. We applied extreme gradient boosting using selected features to develop a simple questionnaire predicting sleep disorders (SLEEPS). The accuracy of the algorithm was evaluated using the area under the receiver operating characteristics curve., Results: In total, 9 features were selected to construct SLEEPS. SLEEPS showed high accuracy, with an area under the receiver operating characteristics curve of greater than 0.897 for all 3 sleep disorders, and consistent performance across both sets of data. We found that the distinction between COMISA and OSA was critical for accurate prediction. A publicly accessible website was created based on the algorithm that provides predictions for the risk of the 3 sleep disorders and shows how the risk changes with changes in weight or age., Conclusions: SLEEPS has the potential to improve the diagnosis and treatment of sleep disorders by providing more accessibility and convenience. The creation of a publicly accessible website based on the algorithm provides a user-friendly tool for assessing the risk of OSA, COMISA, and insomnia., (©Seokmin Ha, Su Jung Choi, Sujin Lee, Reinatt Hansel Wijaya, Jee Hyun Kim, Eun Yeon Joo, Jae Kyoung Kim. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 21.09.2023.)

Obstructive sleep apnea (OSA) may lead to white mater (WM) disruptions and cognitive deficits. However, no studies have investigated the full extent of the brain WM, and its associations with cognitive deficits in OSA remain unclear. We thus applied diffusion tensor imaging (DTI) tractography with multi-fiber models and used atlas-based bundle-specific approach to investigate the WM abnormalities for various tracts of the cerebral cortex, thalamus, brainstem, and cerebellum in patients with untreated OSA. We enrolled 100 OSA patients and 63 healthy controls. Fractional anisotropy (FA) and mean diffusivity (MD) values mapped on 33 regions of interest including WM tracts of cortex, thalamus, brainstem, and cerebellum were obtained from tractography-based reconstructions. We compared FA/MD values between groups and correlated FA/MD with clinical data in the OSA group after controlling for age and body mass index. OSA patients showed significantly lower FA values in multiple WM fibers including corpus callosum, inferior fronto-occipital fasciculus, middle/superior longitudinal fasciculi, thalamic radiations, and uncinate (FDR <0.05). Higher FA values were found in medial lemniscus of patients compared to controls (FDR <0.05). Lower FA values of rostrum of corpus callosum correlated with lower visual memory performance in OSA group (p < .005). Our quantitative DTI analysis demonstrated that untreated OSA could negatively impact the integrity of pathways more broadly, including brainstem structures such as medial lemniscus, in comparison to previous findings. Fiber tract abnormalities of the rostral corpus callosum were associated with impaired visual memory in untreated OSA may provide insights into the related pathomechanism., (© 2023 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.)

Objectives: Many patients with obstructive sleep apnea syndrome (OSAS) have nocturia. However, the predictive index of nocturia in patients with OSAS is currently not well known. We aimed to investigate the prevalence of nocturia in patients with OSAS and determine the factors that could predict nocturia in these patients., Methods: In this retrospective cross-sectional study, we enrolled 1,264 untreated patients with OSAS (Apnea-Hypopnea Index, AHI ≥5/h on polysomnography [PSG]) from January 2017 to January 2020. Participants completed the Beck Depression Inventory-II (BDI-II), Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Epworth Sleepiness Scale. Participants were divided by sex and then subdivided into nocturia and non-nocturia groups according to the following question, "Do you go to the bathroom two times or more during your sleep?" Participants' characteristics and underlying disease were investigated, and all information, including PSG data, was compared between the two groups using the t-test or chi-square test., Results: Overall, 35.2% (337/958) of male participants with OSAS and 59.8% (183/306) of female participants with OSAS had nocturia. The nocturia group was older; scored higher on the BDI-II, PSQI, and ISI; and had more underlying disease in both sexes. There was no difference in the AHI between the two groups among both sexes, but the hypoxia-related PSG parameters and sleep quality parameters, such as higher 90% oxygen desaturation index (90% ODI), lesser N3 sleep, and higher wakefulness after sleep onset, were worse among male participants with OSAS in the nocturia group than in the non-nocturia group. In multivariate logistic analysis, 90% ODI was an independent risk factor associated with nocturia in male participants with OSAS., Conclusions: Considerable number of patients with OSAS had nocturia and poor sleep quality. Nocturia should be evaluated in male OSAS patients with severe hypoxia observed during sleep., Competing Interests: The authors have declared that no competing interests exist.

Study Objectives: Previous functional MRI studies have reported altered brain networks in patients with obstructive sleep apnea (OSA). However, the extent and pattern of abnormal connectivity were inconsistent across studies, and cerebrocerebellar connections have been rarely assessed. We investigated functional network changes in cerebral and cerebellar cortices of OSA patients., Methods: Resting-state functional MRI, polysomnography, and neuropsychological (NP) test data were acquired from 74 OSA patients (age: 45.8 ± 10.7 years) and 33 healthy subjects (39.6 ± 9.3 years). Connectivity matrices were extracted by computing correlation coefficients from various regions of interest, and Fisher r-to-z transformations. In the functional connections that showed significant group differences, linear regression was conducted to examine the association between connectivity and clinical characteristics., Results: Patients with OSA showed reduced functional connectivity (FC) in cerebrocerebellar connections linking different functional networks, and greater FC in cortical between-network connections in prefrontal regions involving the default mode network (DMN) and the control network. For OSA group, we found no correlation between FC and sleep parameters including lowest SaO2 and arousal index in the connections where significant associations were observed in healthy subjects. FC changes in DMN areas were related to reduced verbal fluency in OSA. Lower local efficiency and lower clustering coefficient of the salience network in the left cerebellum were also observed in OSA., Conclusions: OSA affects mainly the cerebrocerebellar pathway. The disruption of function in these connections are related to sleep fragmentation and hypoxia during sleep. These abnormal network functions, especially DMN, are suggested to participate in cognitive decline of OSA., (© Sleep Research Society 2021. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Altered cerebral perfusion has been reported in obstructive sleep apnea (OSA). Using dynamic susceptibility contrast MRI, we compared cerebral perfusion between male OSA patients and male healthy reference subjects and assessed correlations of perfusion abnormalities of OSA patients with sleep parameters and neuropsychological deficits at 3 T MRI, polysomnography and neuropsychological tests in 68 patients with OSA and 21 reference subjects. We found lower global and regional cerebral blood flow and cerebral blood volume, localized mainly in bilateral parietal and prefrontal cortices, as well as multiple focal cortical and deep structures related to the default mode network and attention network. In the correlation analysis between regional hypoperfusion and parameters of polysomnography, different patterns of regional hypoperfusion were distinctively associated with parameters of intermittent hypoxia and sleep fragmentation, which involved mainly parietal and orbitofrontal cortices, respectively. There was no association between brain perfusion and cognition in OSA patients in areas where significant association was observed in reference subjects, largely overlapping with nodes of the default mode network and attention network. Our results suggest that impaired cerebral perfusion in important areas of functional networks could be an important pathomechanism of neurocognitive deficits in OSA.

Purpose: The aim of this study is to determine the impact of myofunctional therapy support program (MTSP) based on self-efficacy theory compared to no support during myofunctional therapy (MT) in patients with obstructive sleep apnea (OSA)., Methods: Thirty-one patients with OSA were randomized into two groups: 12 weeks of treatment with the MTSP developed in this study (experimental group) and one education session of MT (control group). Patients were evaluated at the beginning and the end of the study using questionnaires (self-efficacy scale, Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, snoring intensity and frequency, dry mouth) and polysomnography., Results: The control (n = 15) and experimental (n = 16) groups had similar results for all variables at study entry. The control group showed no significant change in any variables during the study period. In contrast, the experimental group showed a significant increase in self-efficacy 61.38 ± 9.50 to 65.56 ± 10.89 (p = 0.020) and a significant decrease in apnea-hypopnea index (AHI) 19.51 ± 11.41 to 14.11 ± 9.13 (p = 0.039), daytime sleepiness 9.88 ± 3.84 to 7.56 ± 3.42 (p = 0.028), snoring intensity 5.57 ± 3.13 to 4.44 ± 2.68 (p = 0.008), and dry mouth 6.44 ± 3.14 to 3.63 ± 2.33 (p = 0.005), compared to the baseline. No significant change in lowest SaO2 (p = 0.969), sleep quality (p = 0.307), and snoring frequency (p = 0.321) during the study period., Conclusions: The intensive and interactive intervention of MTSP improved the self-efficacy of OSA patients, and consequently, resulted in sign and symptom relief, such as AHI, daytime sleepiness, snoring and dry mouth. The MTSP was dedicated to the nurse practitioner to improve the way to dispense the MT. This research has implications for the successful treatment of OSA.

Study Objectives: Neurocognitive impairment is one of the daytime symptoms of obstructive sleep apnea (OSA). We proposed to use tract-specific statistical analysis (TSSA) to investigate whether there are fiber tract abnormalities in OSA, which may be undiscovered using voxel-based approaches, and whether such tract-specific disruptions in brain connectivity are associated with neuropsychological deficits in patients with untreated OSA., Methods: We enrolled 38 patients with OSA diagnosed by overnight polysomnography, and 41 healthy sleepers. Fractional anisotropy (FA) and mean diffusivity (MD) maps were obtained from whole-brain diffusion tensor imaging, and TSSA were used to assess regional deficits of white matter tracts. All participants underwent a battery of neuropsychological tests. To evaluate the association between FA values and clinical, polysomnographic, and neuropsychological parameters in the OSA group, permutation-based tests for correlation were performed preceding cluster-based statistics., Results: Compared to healthy controls, patients with OSA showed decreased values of FA in the left and right anterior thalamic radiations, and right uncinate fasciculus (UNC) (p < 0.001, p = 0.005, and p = 0.008, respectively). A lower score of digit span backward was associated with lower FA values of right UNC in the OSA group (p = 0.023). The Rey Complex Figure Test copy score revealed a positive correlation with FA values in the right UNC (p = 0.010)., Conclusions: The TSSA method indeed identified previously unrevealed tract-specific disruptions in OSA. Furthermore, reduced FA values in the frontal lobe portion of the right UNC which has been known to be involved in working memory function were significantly associated with lower cognitive performance in patients with untreated OSA., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: The objectives of this study were to investigate the relationship between a low libido and objective sleep parameters as well as mood disturbances in patients with obstructive sleep apnea syndrome (OSA)., Methods: We enrolled 436 untreated patients who were newly diagnosed with OSA (all male, mean age 42.8 years). Patients completed the Symptom checklist-90-Revised (SCL-90-R), Epworth Sleepiness Scale (ESS), Beck Depression Inventory-II (BDI), and Beck Anxiety Inventory (BAI). Patients were divided into low-libido and normal-libido groups according to their response to the statement "Loss of sexual interest or pleasure" on the SCL-90-R., Results: Approximately 23% of patients reported a low libido. Patients with a low libido were older (47.5 ± 9.0 vs. 41.4 ± 11.1 years; p < 0.001), had more nocturia (33.3% vs. 16.6%; p < 0.001), higher BDI (9.0 (5.0-14.0) vs. 5.0 (2.0-9.0); p < 0.001) and BAI score (11.0 (6.3-16.8) vs. 5.0 (2.0-10.0); p < 0.001). These patients had a lower non-REM sleep stage 3 (N3) % (0.1 (0-4.0) vs. 2.3 (0.1-7.9); p < 0.001). Multivariate analysis revealed that older age and higher BDI score were independent factors associated with a low libido., Conclusions: Men with untreated OSA suffered from a low libido. Older age and depressed mood were the most important factors of low libido in middle-aged men with OSA., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this study, we propose a method for the automated detection of obstructive sleep apnea (OSA) from a single-lead electrocardiogram (ECG) using a convolutional neural network (CNN). A CNN model was designed with six optimized convolution layers including activation, pooling, and dropout layers. One-dimensional (1D) convolution, rectified linear units (ReLU), and max pooling were applied to the convolution, activation, and pooling layers, respectively. For training and evaluation of the CNN model, a single-lead ECG dataset was collected from 82 subjects with OSA and was divided into training (including data from 63 patients with 34,281 events) and testing (including data from 19 patients with 8571 events) datasets. Using this CNN model, a precision of 0.99%, a recall of 0.99%, and an F 1 -score of 0.99% were attained with the training dataset; these values were all 0.96% when the CNN was applied to the testing dataset. These results show that the proposed CNN model can be used to detect OSA accurately on the basis of a single-lead ECG. Ultimately, this CNN model may be used as a screening tool for those suspected to suffer from OSA.

Study Objectives: This retrospective study was conducted to evaluate the associations and interactions among obstructive sleep apnea (OSA), chronic kidney disease (CKD), and metabolic syndrome (MS)., Methods: This study included 1,732 subjects (1,482 male and 250 female) in whom OSA was diagnosed by polysomnography. The severity of OSA was defined as mild, moderate, or severe with an apnea-hypopnea index (AHI) score of 5 to < 15, 15 to < 30, and ≥ 30 events/h, respectively. CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m 2 or albuminuria., Results: The prevalence of MS was 29.2% (n = 505). One hundred twenty-nine subjects (7.4%) had CKD. In subjects with MS, CKD prevalence increased progressively with OSA severity: 7.4%, 12.5%, and 15.8% in those with mild, moderate, or severe OSA, respectively ( P = .025). Each 10-point increment in AHI score was independently associated with a 1.15-fold higher prevalence of CKD [95% confidence interval (CI), 1.036-1.280; P = .009] after adjustment for all individual components of MS. On the contrary, in those without MS, AHI was not associated with increased odds for CKD [odds ratio, 1.054; 95% CI, 0.930-1.195]., Conclusions: The independent association between OSA severity and CKD prevalence was observed only in subjects with MS. Further studies are needed to ascertain if OSA contributes to the development of CKD in subjects with MS., (© 2017 American Academy of Sleep Medicine)

Objectives: Obstructive sleep apnea (OSA) is commonly associated with neural and cognitive deficits induced by recurrent hypoxemia and sleep fragment. The aims of this study were to use statistical parametric mapping (SPM) to analyze changes in regional cerebral blood flow (rCBF) in untreated patients with severe OSA before and after nasal continuous positive airway pressure (CPAP) treatment, examine the impact of OSA-related variables on rCBF, and assess the therapeutic effect of nasal CPAP treatment., Methods: Thirty male patients with severe OSA underwent brain single photon emission computed tomography (SPECT) scans twice before and after nasal CPAP treatment for ≥6 months, whereas 26 healthy controls underwent a single SPECT scan. The rCBF differences were compared between two OSA sub-groups (untreated and treated) and the control group, and correlations between rCBF differences and clinical parameters were analyzed., Results: Compared with the controls, the untreated OSA patients showed a significantly lower rCBF in multiple brain areas. After the treatment, partial reversal of the rCBF decreases was observed in the limbic and prefrontal areas. Moreover, complete reversal of the rCBF decreases was observed in the medial orbitofrontal, angular and cerebellar areas. Significant improvements in some clinical and polysomnographic variables (Epworth Sleepiness Scale, apnea-hypopnea index, CPAP duration, and arousal index) paralleled the rCBF changes after the treatment., Conclusions: Decreased rCBF in severe OSA was significantly reversible by CPAP treatment and correlated with the improvements in the apnea-hypopnea index, arousal index, CPAP duration and Epworth Sleepiness Scale. These results suggest that long-term CPAP treatment improves rCBF in areas responsible for executive, affective, and memory function., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Study Objectives: To investigate whether sleep perception (SP), defined by the ratio of subjective and objective total sleep time, and habitual sleep time in various sleep disorders may be based on comorbid insomnia status., Methods: We enrolled 420 patients (age 20-79 y) who underwent polysomnography (PSG). They were divided into three groups based on chief complaints: chronic insomnia (CI, n = 69), patients with both obstructive sleep apnea and insomnia (OSA-I, n = 49) or OSA only (OSA, n = 149). Healthy volunteers were also recruited (normal controls [NC], n = 80). We compared differences in PSG parameters and habitual sleep duration and investigated the discrepancy between objective and subjective total sleep time (TST) and sleep latency among four groups. Subjective TST was defined as sleep time perceived by participants the next morning of PSG., Results: SP for TST was highest in the OSA group (median 92.9%), and lowest in the CI group (80.3%). SP of the NC group (91.4%) was higher than the CI, but there was no difference between OSA-I and OSA groups. OSA-I had higher depressive mood compared to the OSA group (p < 0.001). SP was positively associated with the presence of OSA and habitual sleep duration and negatively related to the presence of insomnia and arousal index of PSG. Insomnia patients with (OSA-I) or without OSA (CI) reported the smallest discrepancy between habitual sleep duration and objective TST., Conclusions: Patients with OSA with or without insomnia have different PSG profiles, which suggests that objective measures of sleep are an important consideration for differentiating subtypes of insomnia and tailoring proper treatment., Commentary: A commentary on this articles appears in this issue on page 1437., (© 2016 American Academy of Sleep Medicine)

Objective: Insomnia symptoms are prevalent in subjects with obstructive sleep apnea syndrome (OSA) and are important risk factors for suicidal ideation (SI). However, the significance of SI has not been clearly demonstrated in persons with both OSA and insomnia. We aimed to investigate the prevalence of SI and its relationship with insomnia symptoms, mood, and other relevant factors., Methods: A total of 117 consecutive subjects with untreated OSA (apnea-hypopnea index ≥5/h) participated in the study. They completed questionnaires regarding SI ([BDI-II], item 9), insomnia symptoms (Insomnia Severity Index [ISI]), depressive mood (modified BDI-II [mBDI-II], which excluded items on SI and sleep disturbances), dysfunctional beliefs and attitudes about sleep (DBAS), social support, and quality of life., Results: The overall prevalence of SI was 20.5% in subjects with OSA. A total of 32 subjects (27.4%) reported significant insomnia symptoms (ISI ≥ 15). Higher SI was associated with higher scores on ISI, DBAS, and mBDI-II and lower scores on social support and quality of life questionnaires. The severity of insomnia was positively correlated with depressive mood. The relationship between SI and insomnia severity was insignificant after adjusting for depressive symptom severity., Conclusion: Patients with OSA may have SI and insomnia symptoms. Collinearity was observed between sleep and mood disturbances. Yet, it is remarkable to find a significant association between OSA and SI, which are additional contributions to insomnia. This study suggests the necessity of integrated approaches to SI and related factors for the comprehensive treatment of OSA., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Study Objectives: To investigate differences in cortical thickness in patients with obstructive sleep apnea (OSA) syndrome and healthy controls., Design: Cortical thickness was measured using a three-dimensional surface-based method that enabled more accurate measurement in deep sulci and localized regional mapping., Setting: University hospital., Patients: Thirty-eight male patients with severe OSA (mean apnea-hypopnea index > 30/h) and 36 age-matched male healthy controls were enrolled., Interventions: Cortical thickness was obtained at 81,924 vertices across the entire brain by reconstructing inner and outer cortical surfaces using an automated anatomical pipeline., Measurements: Group difference in cortical thickness and correlation between patients' data and thickness were analyzed by a general linear model., Results: Localized cortical thinning in patients was found in the orbitorectal gyri, dorsolateral/ventromedial prefrontal regions, pericentral gyri, anterior cingulate, insula, inferior parietal lobule, uncus, and basolateral temporal regions at corrected P < 0.05. Patients with OSA showed impaired attention and learning difficulty in memory tests compared to healthy controls. Higher number of respiratory arousals was related to cortical thinning of the anterior cingulate and inferior parietal lobule. A significant correlation was observed between the longer apnea maximum duration and the cortical thinning of the dorsolateral prefrontal regions, pericentral gyri, and insula. Retention scores in visual memory tests were associated with cortical thickness of parahippocampal gyrus and uncus., Conclusions: Brain regions with cortical thinning may provide elucidations for prefrontal cognitive dysfunction, upper airway sensorimotor dysregulation, and cardiovascular disturbances in OSA patients, that experience sleep disruption including sleep fragmentation and oxygen desaturation.

Objective: To investigate cortical excitability in patients with obstructive sleep apnea syndrome (OSAS) during wakefulness., Methods: The authors recruited 45 untreated severe OSAS (all males, mean age 47.2 years, mean apnea-hypopnea index=44.6h(-1)) patients and 44 age-matched healthy male volunteers (mean apnea-hypopnea index=3.4h(-1)). The TMS parameters measured were resting motor threshold (RMT), motor evoked potential (MEP) amplitude, cortical silent period (CSP), and short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). These parameters were measured in the morning (9-10 am) more than 2h after arising and the parameters of patients and controls were compared. The Epworth Sleepiness Scale (ESS) and the Stanford Sleepiness Scale (SSS) were also measured before the TMS study., Results: OSAS patients had a significantly higher RMT and a longer CSP duration (t-test, p<0.001) compared to healthy volunteers. No significant difference was observed between MEP amplitudes at any stimulus intensity or between the SICI (2, 3, 5ms) and ICF (10, 15, 20ms) values of OSAS patients and healthy volunteers (p>0.05)., Conclusions: This TMS-based study suggests that untreated severe OSAS patients have imbalanced cortical excitabilities that enhanced inhibition or decreased brain excitability when awake during the day.

Adiponectin, an adipose tissue-derived hormone, has been negatively related to obstructive sleep apnea syndrome. Besides sleep apnea, children with Prader-Willi syndrome (PWS) may have excessive daytime sleepiness and rapid eye movement (REM) sleep abnormality. The aim of this study is to determine whether changes in sleep structures are related to plasma adiponectin levels in PWS. Correlations between adiponectin level and sleep variables were analyzed in 28 children with PWS and 18 controls. Overnight polysomnography was performed. The fasting plasma adiponectin levels were higher in the children with PWS than in the controls (P = 0.0006). In the PWS, Epworth sleepiness scale was significantly higher (P = 0.002); sleep latency (P = 0.003) and REM latency (P = 0.001) were significantly shortened; the apnea-hypopnea index (AHI) was significantly increased (P = 0.0001); and the duration of non-rapid eye movement (NREM) sleep stages 3 and 4 was decreased (P = 0.005). Multiple regression analysis revealed correlations between the adiponectin level and the total sleep time (beta = 0.688, P = 0.009), AHI (beta = 1.274, P = 0.010), REM latency (beta = -0.637, P = 0.021) and the percentage of NREM sleep (beta = -7.648, P = 0.002) in PWS. In children with PWS, higher plasma adiponectin levels were independently associated with several sleep variables, which was not observed in the control group. These results suggest a potential influence of elevated adiponectin level on the sleep structures in PWS.

Study Objectives: To investigate differences in brain gray matter concentrations or volumes in patients with obstructive sleep apnea syndrome (OSA) and healthy volunteers., Designs: Optimized voxel-based morphometry, an automated processing technique for MRI, was used to characterize structural differences in gray matter in newly diagnosed male patients., Setting: University hospital., Patients and Participants: The study consisted of 36 male OSA and 31 non-apneic male healthy volunteers matched for age (mean age, 44.8 years)., Interventions: Using the t-test, gray matter differences were identified. The statistical significance level was set to a false discovery rate P < 0.05 with an extent threshold of k(E) > 200 voxels., Measurements and Results: The mean apnea-hypopnea index (AHI) of patients was 52.5/h. On visual inspection of MRI, no structural abnormalities were observed. Compared to healthy volunteers, the gray matter concentrations of OSA patients were significantly decreased in the left gyrus rectus, bilateral superior frontal gyri, left precentral gyrus, bilateral frontomarginal gyri, bilateral anterior cingulate gyri, right insular gyrus, bilateral caudate nuclei, bilateral thalami, bilateral amygdalo-hippocampi, bilateral inferior temporal gyri, and bilateral quadrangular and biventer lobules in the cerebellum (false discovery rate P < 0.05). Gray matter volume was not different between OSA patients and healthy volunteers., Conclusions: The brain gray matter deficits may suggest that memory impairment, affective and cardiovascular disturbances, executive dysfunctions, and dysregulation of autonomic and respiratory control frequently found in OSA patients might be related to morphological differences in the brain gray matter areas.

Study Objectives: To investigate changes in regional cerebral blood flow (rCBF) in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS)., Design: We compared the 99mTc-ethylcysteinate dimer (ECD) single photon emission computed tomography (SPECT) images of patients with OSAHS with those of age- and sex-matched healthy volunteers., Setting: University hospital., Patients and Participants: Twenty-seven patients with severe OSAHS and 27 healthy volunteers underwent 99mTc-ECD brain SPECT studies., Intervention: For statistical parametric mapping analysis, all SPECT images were spatially normalized to the standard SPECT template and then smoothed using a 14-mm full-width at half-maximum Gaussian kernel. The Student t test was used for the statistical analysis., Measurements and Results: The mean age of patients and subjects was 44.3 years (range 31-58). All patients underwent overnight polysomnography. The mean apnea-hypopnea index of patients was 60.4 +/- 17.6 per hour (range 33 -104), indicating severe OSAHS. All patients snored heavily and had daytime sleepiness (mean Epworth Sleepiness Scale score, 10.7 +/- 3.7, range 6-12). Statistical parametric mapping analysis showed that rCBF in patients with OSAHS was significantly reduced in bilateral parahippocampal gyri and in the right lingual gyrus, as compared with that of healthy volunteers (P < 0.05 with false discovery rate correction). Moreover, apnea-hypopnea indexes of patients were negatively correlated with rCBF in the right pericentral gyrus and right cuneus at uncorrected P < 0.001., Conclusions: Our results show the altered rCBF pattern in bilateral parahippocampal gyri, right lingual gyrus, pericentral gyrus, and cuneus in patients with severe OSAHS. These findings may partly explain the deficit in memory, spatial learning, executive function, and attention, which are frequently found in patients with OSAHS.