Efficacy of cranial electrotherapy stimulation on mood and sense of well-being in people with subclinical insomnia.

Cranial electrotherapy stimulation is a non-invasive brain stimulation method characterised by using a microcurrent. The objective of the study was to investigate whether a novel device with a stable supplement of electronic stimulation would improve sleep and the accompanying mood symptoms in people with subclinical insomnia. People who had insomnia symptoms without meeting the criteria for chronic insomnia disorder were recruited and randomly assigned to an active or a sham device group. They were required to use the provided device for 30 min each time, twice a day for 2 weeks. Outcome measures included questionnaires for sleep, depression, anxiety, and quality of life, 4 day actigraphy, and 64-channel electroencephalography. Fifty-nine participants (male 35.6%) with a mean age of 41.1 ± 12.0 years were randomised. Improvement of depression (p = 0.032) and physical well-being (p = 0.041) were significant in the active device group compared with the sham device group. Anxiety was also improved in the active device group, although the improvement was not statistically significant (p = 0.090). Regarding sleep, both groups showed a significant improvement in subjective rating, showing no significant group difference. The change in electroencephalography after the 2 week intervention was significantly different between the two groups, especially for occipital delta (p = 0.008) and beta power (p = 0.012), and temporo-parieto-occipital theta (p = 0.022). In conclusion, cranial electrotherapy stimulation can serve as an adjunctive therapy to ameliorate psychological symptoms and to alter brain activity. The effects of the device in a clinical population and an optimal set of parameters of stimulation should be further investigated.

Modest Effects of Neurofeedback-Assisted Meditation Using a Wearable Device on Stress Reduction: A Randomized, Double-Blind, and Controlled Study.

BACKGROUND: To evaluate the therapeutic effectiveness and safety of a neurofeedback wearable device for stress reduction. METHODS: A randomized, double-blind, controlled study was designed. Participants had psychological stress with depression or sleep disturbances. They practiced either neurofeedback-assisted meditation (n = 20; female, 15 [75.0%]; age, 49.40 ± 11.76 years) or neurofeedback non-assisted meditation (n = 18; female, 11 [61.1%]; age, 48.67 ± 12.90 years) for 12 minutes twice a day for two weeks. Outcome variables were self-reported questionnaires, including the Korean version of the Perceived Stress Scale, Beck Depression Inventory-II, Insomnia Severity Index, Pittsburgh Sleep Quality Index, and State Trait Anxiety Index, quantitative electroencephalography (qEEG), and blood tests. Satisfaction with device use was measured at the final visit. RESULTS: The experimental group had a significant change in PSS score after two weeks of intervention compared with the control group (6.45 ± 0.95 vs. 3.00 ± 5.54, P = 0.037). State anxiety tended to have a greater effect in the experimental group than in the control group (P = 0.078). Depressive mood and sleep also improved in each group, with no significant difference between the two groups. There were no significant differences in stress-related physiological parameters, such as stress hormones or qEEG, between the two groups. Subjective device satisfaction was significantly higher in the experimental group than in the control group (P = 0.008). CONCLUSION: Neurofeedback-assisted meditation using a wearable device can help improve subjective stress reduction compared with non-assisted meditation. These results support neurofeedback as an effective adjunct to meditation for relieving stress. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0007413.

The Effect of Remimazolam on Seizure Profile, Hemodynamics, and Recovery in Patients With Electroconvulsive Therapy Comparison With Propofol and Etomidate: A Retrospective Study.

OBJECTIVES: To compare seizure-related, hemodynamic, and recovery outcomes when using remimazolam for ECT with those of other anesthetics, specifically propofol and etomidate. METHODS: A total of 49 patients who underwent 405 ECT treatment sessions under general anesthesia were retrospectively analyzed. Remimazolam, propofol, and etomidate were used for 93, 138, and 174 ECT sessions, respectively. The primary outcome was durations of motor and electroencephalogram (EEG) seizure activity, whereas secondary outcomes included hemodynamics (ie, mean arterial pressure [MAP] and heart rate [HR] at various time points from induction to postanesthesia care unit [PACU] discharge), antihypertensive drugs administration after electrical stimulus, and recovery profiles (ie, length of PACU stay and incidence of postictal confusion). RESULTS: Durations of motor and EEG seizures were shorter for remimazolam than etomidate (motor, P < 0.001; EEG, P = 0.003) but similar compared with propofol (motor, P = 0.191; EEG, P = 0.850). During seizure, remimazolam showed a comparable MAP and HR to etomidate (MAP: P = 0.806; HR: P = 0.116). The antihypertensive drug use was lowest for remimazolam (6.8%), followed by propofol (35.6%) and etomidate (65.6%), and the mean length of PACU stay was comparable for remimazolam (19.7 min), propofol (22.8 min), and etomidate (24.5 min). The occurrence of postictal confusion did not differ among the 3 agents (P > 0.050). CONCLUSIONS: Remimazolam is a promising anesthetic option for ECT because of its comparable seizure profiles, stable hemodynamics, and comparable PACU stay when compared with propofol and etomidate without additional adverse events.

Altered Brain Glymphatic Flow at Diffusion-Tensor MRI in Rapid Eye Movement Sleep Behavior Disorder.

Background Brain glymphatic dysfunction may contribute to the development of α-synucleinopathies. Yet, noninvasive imaging and quantification remain lacking. Purpose To examine glymphatic function of the brain in isolated rapid eye movement sleep behavior disorder (RBD) and its relevance to phenoconversion with use of diffusion-tensor imaging (DTI) analysis along the perivascular space (ALPS). Materials and Methods This prospective study included consecutive participants diagnosed with RBD, age- and sex-matched control participants, and participants with Parkinson disease (PD) who were enrolled and examined between May 2017 and April 2020. All study participants underwent 3.0-T brain MRI including DTI, susceptibility-weighted and susceptibility map-weighted imaging, and/or dopamine transporter imaging using iodine 123-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane SPECT at the time of participation. Phenoconversion status to α-synucleinopathies was unknown at the time of MRI. Participants were regularly followed up and monitored for any signs of α-synucleinopathies. The ALPS index reflecting glymphatic activity was calculated by a ratio of the diffusivities along the x-axis in the projection and association neural fibers to the diffusivities perpendicular to them and compared according to the groups with use of the Kruskal-Wallis and Mann-Whitney U tests. The phenoconversion risk in participants with RBD was evaluated according to the ALPS index with use of a Cox proportional hazards model. Results Twenty participants diagnosed with RBD (12 men; median age, 73 years [IQR, 66-76 years]), 20 control participants, and 20 participants with PD were included. The median ALPS index was lower in the group with RBD versus controls (1.53 vs 1.72; P = .001) but showed no evidence of a difference compared with the group with PD (1.49; P = .68). The conversion risk decreased with an increasing ALPS index (hazard ratio, 0.57 per 0.1 increase in the ALPS index [95% CI: 0.35, 0.93]; P = .03). Conclusion DTI-ALPS in RBD demonstrated a more severe reduction of glymphatic activity in individuals with phenoconversion to α-synucleinopathies. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Filippi and Balestrino in this issue.

Real-Time Detection of Sleep Apnea Based on Breathing Sounds and Prediction Reinforcement Using Home Noises: Algorithm Development and Validation.

BACKGROUND: Multinight monitoring can be helpful for the diagnosis and management of obstructive sleep apnea (OSA). For this purpose, it is necessary to be able to detect OSA in real time in a noisy home environment. Sound-based OSA assessment holds great potential since it can be integrated with smartphones to provide full noncontact monitoring of OSA at home. OBJECTIVE: The purpose of this study is to develop a predictive model that can detect OSA in real time, even in a home environment where various noises exist. METHODS: This study included 1018 polysomnography (PSG) audio data sets, 297 smartphone audio data sets synced with PSG, and a home noise data set containing 22,500 noises to train the model to predict breathing events, such as apneas and hypopneas, based on breathing sounds that occur during sleep. The whole breathing sound of each night was divided into 30-second epochs and labeled as "apnea," "hypopnea," or "no-event," and the home noises were used to make the model robust to a noisy home environment. The performance of the prediction model was assessed using epoch-by-epoch prediction accuracy and OSA severity classification based on the apnea-hypopnea index (AHI). RESULTS: Epoch-by-epoch OSA event detection showed an accuracy of 86% and a macro F1-score of 0.75 for the 3-class OSA event detection task. The model had an accuracy of 92% for "no-event," 84% for "apnea," and 51% for "hypopnea." Most misclassifications were made for "hypopnea," with 15% and 34% of "hypopnea" being wrongly predicted as "apnea" and "no-event," respectively. The sensitivity and specificity of the OSA severity classification (AHI≥15) were 0.85 and 0.84, respectively. CONCLUSIONS: Our study presents a real-time epoch-by-epoch OSA detector that works in a variety of noisy home environments. Based on this, additional research is needed to verify the usefulness of various multinight monitoring and real-time diagnostic technologies in the home environment.

Prediction of Sleep Stages Via Deep Learning Using Smartphone Audio Recordings in Home Environments: Model Development and Validation.

BACKGROUND: The growing public interest and awareness regarding the significance of sleep is driving the demand for sleep monitoring at home. In addition to various commercially available wearable and nearable devices, sound-based sleep staging via deep learning is emerging as a decent alternative for their convenience and potential accuracy. However, sound-based sleep staging has only been studied using in-laboratory sound data. In real-world sleep environments (homes), there is abundant background noise, in contrast to quiet, controlled environments such as laboratories. The use of sound-based sleep staging at homes has not been investigated while it is essential for practical use on a daily basis. Challenges are the lack of and the expected huge expense of acquiring a sufficient size of home data annotated with sleep stages to train a large-scale neural network. OBJECTIVE: This study aims to develop and validate a deep learning method to perform sound-based sleep staging using audio recordings achieved from various uncontrolled home environments. METHODS: To overcome the limitation of lacking home data with known sleep stages, we adopted advanced training techniques and combined home data with hospital data. The training of the model consisted of 3 components: (1) the original supervised learning using 812 pairs of hospital polysomnography (PSG) and audio recordings, and the 2 newly adopted components; (2) transfer learning from hospital to home sounds by adding 829 smartphone audio recordings at home; and (3) consistency training using augmented hospital sound data. Augmented data were created by adding 8255 home noise data to hospital audio recordings. Besides, an independent test set was built by collecting 45 pairs of overnight PSG and smartphone audio recording at homes to examine the performance of the trained model. RESULTS: The accuracy of the model was 76.2% (63.4% for wake, 64.9% for rapid-eye movement [REM], and 83.6% for non-REM) for our test set. The macro F1-score and mean per-class sensitivity were 0.714 and 0.706, respectively. The performance was robust across demographic groups such as age, gender, BMI, or sleep apnea severity (accuracy 73.4%-79.4%). In the ablation study, we evaluated the contribution of each component. While the supervised learning alone achieved accuracy of 69.2% on home sound data, adding consistency training to the supervised learning helped increase the accuracy to a larger degree (+4.3%) than adding transfer learning (+0.1%). The best performance was shown when both transfer learning and consistency training were adopted (+7.0%). CONCLUSIONS: This study shows that sound-based sleep staging is feasible for home use. By adopting 2 advanced techniques (transfer learning and consistency training) the deep learning model robustly predicts sleep stages using sounds recorded at various uncontrolled home environments, without using any special equipment but smartphones only.

Age of Diagnosis and Comorbid PLMD Predict Poor Response of REM Behavior Disorder to Clonazepam.

Previous studies have shown the therapeutic effects of clonazepam for rapid eye movement sleep behavior disorder (RBD), but they had several limitations such as the lack of clear definition of treatment outcomes and little information about adjuvant therapy. The aims of this study were to evaluate the treatment outcomes with clonazepam and to explore possible determinants of treatment response. We performed a retrospective medical chart review of 171 patients with RBD. All the participants underwent overnight polysomnography and completed questionnaires. The positive treatment response was defined as the absence of disruptive behaviors causing sleep-related injuries during the last year of follow-up. Among the 171 patients presented with disruptive behaviors, 155 (90.6%) experienced positive treatment responses. Of the responders, 18 (11.6%) received adjunctive medication due to insufficient therapeutic effect of clonazepam monotherapy. After adjusted analysis, an earlier age of diagnosis (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.64-0.86, P < .001) and comorbid periodic limb movement during sleep (OR = 4.96, 95% CI = 1.05-23.33, P = .043) were related to poor treatment response. Clinicians should recognize the predictors of poor treatment response and consider combination therapy for better prevention of sleep-related injuries in those who show unsatisfactory responses to clonazepam monotherapy.

Clinical Perspectives of Parkinson's Disease for Ophthalmologists, Otorhinolaryngologists, Cardiologists, Dentists, Gastroenterologists, Urologists, Physiatrists, and Psychiatrists.

Parkinson's disease (PD) is a multisystemic disorder characterized by various non-motor symptoms (NMS) in addition to motor dysfunction. NMS include sleep, ocular, olfactory, throat, cardiovascular, gastrointestinal, genitourinary, or musculoskeletal disorders. A range of NMS, particularly hyposmia, sleep disturbances, constipation, and depression, can even appear prior to the motor symptoms of PD. Because NMS can affect multiple organs and result in major disabilities, the recognition and multidisciplinary and collaborative management of NMS by physicians is essential for patients with PD. Therefore, the aim of this review article is to provide an overview of the organs that are affected by NMS in PD together with a brief review of pathophysiology and treatment options.

Minimal Effects of Binaural Auditory Beats for Subclinical Insomnia: A Randomized Double-Blind Controlled Study.

BACKGROUND: Auditory binaural beat (BB) stimulation is known to modulate electroencephalographic activity by brain entrainment, but few studies have established whether BB can affect the sleep state. We examined the effect of θ BB in improving sleep disturbances and daytime alertness. METHODS: We conducted double-blind and sham-controlled randomized trial. Subjects with subclinical insomnia were randomly assigned and listened to music for 2 weeks with or without θ BB for 30 minutes before going to sleep. RESULTS: There were 43 participants (32 female; mean age, 34.3 ± 10.4 years) who finished the trial. The insomnia severity decreased at 2 weeks in both groups without significant differences in Insomnia Severity Index score (4.41 ± 4.32 vs 2.71 ± 4.66, P = 0.656), although the effect was much stronger for the music with the BB group than for the music-only group (Cohen d = 1.02 vs 0.58). In awake electroencephalographic analysis, the relative ß power after 2 weeks was higher in the music with the BB group than in the music-only group (0.2 ± 7.02 vs -3.91 ± 6.97, P = 0.041). CONCLUSIONS: Auditory θ BB with music does not induce evident improvement of sleep disturbances more than does pure music, but could alter brain activity toward increasing daytime alertness in subclinical insomnia, which needs to be corroborated in a clinical population.

Implication of Fast Activities of Spectral Analysis in Subjective Sleep Complaints of Elderly Women.

OBJECTIVE: In elderly patients, women have better qualities of sleep than men in objective parameters; however, women subjectively complain more about sleep disturbances than men. We performed visual scoring and spectral analysis of sleep electroencephalograms to explain these gender differences in the degree of arousal, the most representative marker in insomnia. METHODS: A total of 354 participants (≥60 years old) were recruited from a Korean community underwent nocturnal polysomnography (NPSG). A Fast Fourier transform was used for the spectral analysis of the NPSG data. Relative power was calculated as absolute power of each band divided by total absolute power. Difference in total sleep time (D_TST) is obtained by subtracting the total sleep time reported in Pittsburgh Sleep Quality Index (PSQI) from the TST measured by the NPSG. RESULTS: A total of 75 participants (women, 51) were finally analyzed. Women had higher PSQI, longer sleep latencies, sleep inefficiencies, and daytime dysfunctions compared to men. The percentage of stage 1 sleep was higher in men versus in women, whereas percentage of stage 3 sleep was higher in women than in men ( P = .001; P = .001). Women had higher relative alpha and beta powers than men during nonrapid eye movement (NREM) sleep ( P = .017; P = .015). During NREM sleep, beta power was negatively correlated with D_TST ( R = -0.250, P = .033), and relative alpha power in stage 3 sleep was positively correlated with sleep latency in PSQI ( R = 0.267, P = .022). CONCLUSION: Spectral analysis showed that women had more disturbed sleep than men. The result from the spectral analysis may explain hyperarousal in elderly women.

A validation study on three screening questionnaires for obstructive sleep apnea in a Korean community sample.

PURPOSE: Obstructive sleep apnea (OSA) is highly prevalent and causes serious cardiovascular complications. Several screening questionnaires for OSA have been introduced, but only few validation studies have been conducted in general population. The aim of the present study was to assess the diagnostic value of three OSA screening questionnaires (Berlin Questionnaire, BQ; STOP-Bang Questionnaire, STOP-B; Four-Variable Screening Tool, Four-V) in a Korean community sample. METHODS: A total of 1148 community-dwelling participants completed the BQ, STOP-B, and Four-V. An overnight in-laboratory polysomnography (PSG) was conducted in randomly selected 116 participants. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, and area under the curve (AUC) were calculated. RESULTS: The Four-V with cutoff ≥ 8 showed high sensitivity for overall OSA (69.4%), and the Four-V with cutoff ≥ 9 showed high specificity for both overall OSA (81.5%) and moderate to severe OSA (69.0%). On the other hand, the STOP-B showed acceptable sensitivity and specificity for both overall OSA (61.3 and 79.6%, respectively) and moderate to severe OSA (72.4 and 67.8%, respectively). The STOP-Bang also showed the largest area under the receiver-operator characteristic curve for both overall OSA (0.752) and moderate to severe OSA (0.750). The BQ showed the lowest performance in predicting OSA. CONCLUSIONS: Among the three questionnaires, the STOP-B was revealed as the most useful screening tool for OSA in terms of sensitivity, specificity, and area under the receiver-operator characteristic curve in the population of South Korea.

Loss of Substantia Nigra Hyperintensity at 3.0-T MR Imaging in Idiopathic REM Sleep Behavior Disorder: Comparison with 123I-FP-CIT SPECT.

Purpose To examine whether the loss of nigral hyperintensity (NH) on 3.0-T susceptibility-weighted (SW) magnetic resonance (MR) images can help identify high synucleinopathy risk in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD). Materials and Methods Between March 2014 and April 2015, 18 consecutively recruited patients with iRBD were evaluated with 3.0-T SW imaging and iodine 123-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane (123I-FP-CIT) single photon emission computed tomography and compared with 18 healthy subjects and 18 patients with Parkinson disease (PD). Two readers blinded to clinical diagnosis independently assessed the images. 123I-FP-CIT uptake ratios were compared by using the Kruskal-Wallis test, and intra- and interobserver agreements were assessed with the Cohen κ. The synucleinopathy conversion according to NH status was evaluated in patients with iRBD after follow-up. Results NH was intact in seven patients with iRBD and lost in 11. The 123I-FP-CIT uptake ratios were comparable between those with intact NH (mean, 3.22 ± 0.47) and healthy subjects (mean, 3.37 ± 0.47) (P = .495). The 123I-FP-CIT uptake ratios in the 11 patients with iRBD and NH loss (mean, 2.48 ± 0.44) were significantly lower than those in healthy subjects (mean, 3.37 ± 0.47; P < .001) but higher than those in patients with PD (mean, 1.80 ± 0.33; P < .001). The intra- and interobserver agreements were excellent (κ > 0.9). Five patients with iRBD and NH loss developed symptoms of parkinsonism or dementia 18 months after neuroimaging. Conclusion NH loss at 3.0-T SW imaging may be a promising marker for short-term synucleinopathy risk in iRBD. © RSNA, 2017 Online supplemental material is available for this article.

Subjective memory complaints in an elderly population with poor sleep quality.

OBJECTIVES: The association between sleep disturbances and cognitive decline in the elderly has been putative and controversial. We evaluated the relation between subjective sleep quality and cognitive function in the Korean elderly. METHOD: Among 459 community-dwelling subjects, 352 subjects without depression or neurologic disorders (mean age 68.2 ± 6.1) were analyzed in this study. All the participants completed the Korean version of the consortium to establish a registry for Alzheimer's disease neuropsychological battery (CERAD-KN) as an objective cognitive measure and subjective memory complaints questionnaire (SMCQ). Based on the Pittsburgh sleep quality index, two types of sleepers were defined: 'good sleepers' and 'poor sleepers'. RESULTS: There were 192 good sleepers (92 men) and 160 poor sleepers (51 men). Poor sleepers reported more depressive symptoms and more use of sleep medication, and showed higher SMCQ scores than good sleepers, but there was no difference in any assessments of CERAD-KN. In the regression analysis, depressive symptoms and subjective sleep quality were associated with subjective memory complaints (ß = 0.312, p < 0.001; ß = 0.163, p = 0.005). CONCLUSION: In the elderly without depression, poor sleep quality was associated with subjective memory complaints, but not with objective cognitive measures. As subjective memory complaints might develop into cognitive disorders, poor sleep quality in the elderly needs to be adequately controlled.

Progression of cognitive impairments in idiopathic REM sleep behaviour disorder.

BACKGROUND: Idiopathic REM (rapid eye movement) sleep behaviour disorder (iRBD) has been implicated in cognitive impairments, but there is little evidence about progression of cognitive dysfunction in iRBD. METHODS: A retrospective follow-up study with patients with iRBD was performed. Conversion to neurodegenerative disorders was analysed by Kaplan-Meier survival analysis. Neuropsychological test results at baseline were compared between patients with iRBD and healthy controls. 57 patients with iRBD were successfully followed up for changes of cognitive performance over time (follow-up duration 50.84±25.38 months; range 12-108 months). Factors affecting cognitive decline were evaluated with multiple regression analysis and the subgroup analysis for groups with and without conversion was carried out. RESULTS: Among 84 patients with iRBD, conversion occurred in 18 patients and conversion rates were estimated to be 9%, 18% and 35% at 3, 5 and 6 years from diagnosis of iRBD. Individuals with iRBD showed lower z-scores at baseline than controls in Mini-Mental Status Examination, Trail Making Test A, constructional praxis and Executive Clock Drawing Task (CLOX2). Patients with non-converting iRBD showed significant performance decline in memory (p=0.003, Digit span forward) and a worsening tendency of executive functions (p=0.007, frontal assessment battery; p=0.012, Stroop test) at follow-up tests. Cognitive decline was associated with disease duration or follow-up duration, and lower executive function at baseline increased conversion risk (p=0.031). CONCLUSIONS: Patients with iRBD have cognitive impairments at baseline and progressive cognitive decline over time. Even in idiopathic cases without development of any neurodegenerative disease, degenerative changes in cognition seem to be under way.

Smoking Cessation and the Risk of Hyperactive Delirium in Hospitalized Patients: A Retrospective Study.

OBJECTIVES: The acute cessation of smoking often induces symptoms that are similar to those associated with delirium. We aimed to evaluate effects of sudden nicotine abstinence on the development of delirium and its motoric subtypes in hospitalized patients. METHODS: The present study included patients who were referred to psychiatrists by ward physicians due to confusion. The presence of delirium was defined using the Confusion Assessment Method and the Delirium Rating Scale Revised-98, which was also used to assess the severity of delirium. Outcome variables, including the length of hospital stay and 3-month mortality rate, were collected by a retrospective chart review. RESULTS: Delirium was confirmed in 210 of the 293 referred patients. Of the motoric subtypes of delirium, the hyperactive subtype was more common (68.1%) and was related to higher 3-month mortality (odds ratio [OR], 2.189; 95% confidence interval [CI], 1.07 to 4.49; P = 0.033) compared with hypoactive delirium. Patients undergoing sudden cessation of smoking (n = 55) were more likely to exhibit hyperactive delirium than were nonsmokers (P = 0.001). A multivariate analysis revealed that smoking cessation was an independent risk factor for hyperactive delirium (OR, 10.33; 95% CI, 2.31 to 46.09; P = 0.002). In addition, the amount of smoking was positively correlated with the severity of hyperactivity (r = 0.421, P = 0.003). Smoking status did not significantly influence overall delirium incidence. CONCLUSIONS: The present findings demonstrated that nicotine withdrawal was associated with hyperactive delirium, which suggests that they share common pathophysiologies that involve the dopamine, opioid, and cholinergic systems.

Erythrocyte sedimentation rate may help predict severity of obstructive sleep apnea.

PURPOSE: Previous studies have shown a relationship between obstructive sleep apnea (OSA) and erythrocyte sedimentation rate (ESR), a representative marker for inflammation. We aimed to elucidate the possible association between elevated ESR and OSA severity. METHODS: A total of 341 patients who visited a sleep center were retrospectively enrolled. Subjects underwent physical examination, overnight polysomnography (PSG), and blood sampling for ESR and high-sensitivity C-reactive protein (hs-CRP). We compared the ESR and hs-CRP level to OSA severity and measured their correlation with other PSG parameters. RESULTS: The ESR was significantly higher in patients with severe OSA (apnea-hypopnea index (AHI) ≥ 30) than those with simple snoring (AHI < 5; P = 0.016), mild OSA (5 ≤ AHI < 15; P = 0.010), and moderate OSA (15 ≤ AHI < 30; P = 0.042). Similarly, the hs-CRP level in patients with severe OSA was significantly higher than that in patients with simple snoring (P = 0.006) and mild OSA (P = 0.013). Multivariate analysis also showed that elevated ESR was associated with moderate and severe OSA (adjusted OR = 2.231 (P = 0.048) and 2.606 (P = 0.002), respectively) after adjusting for sex, age, body mass index, smoking, hypertension, diabetes mellitus, and hyperlipidemia. However, elevated hs-CRP was not associated with the OSA severity. CONCLUSIONS: ESR more closely correlated with PSG parameters recorded during sleep hypoxic episodes than hs-CRP. Moreover, the ESR may be useful to predict the OSA severity because moderate and severe OSA were independently associated with an elevated ESR.

Impacts of comorbidities on the association between arterial stiffness and obstructive sleep apnea in the elderly.

BACKGROUND: Although the impact of obstructive sleep apnea (OSA) on cardiovascular risk is reasonably well established in middle-aged patients, the debate persists as to whether OSA also increases this risk in the elderly. Arterial stiffness has been used as an early independent predictor of cardiovascular risk. STUDY OBJECTIVES: We sought to determine whether OSA has significant effects on the arterial stiffness in the elderly population and evaluate the impact of comorbidities on the association between arterial stiffness and OSA. METHODS: We performed a cross-sectional study in a university hospital. Elderly participants (≥60 years) were invited to participate in our study between November 2010 and January 2013. OSA was diagnosed using gold standard polysomnography and arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV), cardio-ankle vascular index (CAVI) and central systolic and diastolic blood pressure (cSBP and cDBP). The high-sensitivity C-reactive protein (hs-CRP) level was also measured. RESULTS: We found no significant association between the severity of OSA and the arterial stiffness-related parameters cSBP, cDBP, baPWV, CAVI and hs-CRP. However, in patients with no comorbid medical conditions or use of medications (n = 101), we showed a modest association between OSA and arterial stiffness-related parameters and hs-CRP. CONCLUSION: We conclude that OSA is associated with increased arterial stiffness in an otherwise healthy elderly population, although the association was obviated by comorbidities and medications perhaps due to ceiling effects.

The prevalence of and risk factors for sleep-disordered breathing in an elderly Korean population.

BACKGROUND: There are just a few epidemiological studies on sleep-disordered breathing (SDB) in the elderly, and the results are inconsistent. STUDY OBJECTIVES: We sought to investigate the prevalence of and risk factors for SDB in a representative elderly population with the use of attended nocturnal polysomnography (NPSG). METHODS: Among 6,959 individuals aged ≥ 60 years living in Yongin City, Korea, 696 subjects were selected using random sampling. All the subjects were invited to visit a hospital for NPSG, and SDB was defined as an apnea-hypopnea index ≥ 15. RESULTS: Of the 696 participants investigated, 348 participants completed the sleep study and clinical evaluation. SDB was observed in 127 of the 348 participants, and the prevalence of SDB was 36.5% (52.6% in males and 26.3% in females). A body mass index ≥ 25 was associated with SDB in both male and female subjects, particularly in males, whereas snoring was independently associated with SDB in female participants only. In male participants, SDB was a significant risk factor for hypertension (p = 0.025). CONCLUSIONS: SDB was found to be common among elderly Koreans, and it was more prevalent and severe in male than in female subjects. Health consequences of SDB in the elderly need to be further explored.

Influencing factors on the effect of mandibular advancement device in obstructive sleep apnea patients: analysis on cephalometric and polysomnographic parameters.

BACKGROUND: The purposes of this study were to evaluate clinical outcome of mandibular advancement device (MAD) for obstructive sleep apnea (OSA) patients and to estimate influencing factors on MAD effect. METHODS: From the patients who were diagnosed as OSA by polysomnography at Seoul National University Bundang Hospital from January 2007 to February 2009, the patients who chose MAD as initial treatment option were included. All the patients' data were collected by reviewing and analyzing medical record and radiograph retrospectively. RESULTS: Eighty-six patients (76 males and 10 females; mean age of 51.5 ± 9.8 years) with OSA were included in this study. Total success rate of MAD treatment was 47.7% (41/86 patients). Among cephalometric parameters, lower facial height (35.61 ± 4.26 vs. 38.19 ± 4.89) showed significant difference between success group and non-success group. From the polysomnographic parameters, apnea index (19.79 ± 17.32 vs. 30.08 ± 23.28), average oxygen saturation (95.03 ± 1.42 vs. 94.32 ± 1.56), lowest oxygen saturation (81.44 ± 6.64 vs. 76.87 ± 7.98), oxygen saturation under 90% (4.47 ± 5.90 vs. 9.01 ± 9.29), and oxygen desaturation index (23.58 ± 17.46 vs. 37.16 ± 22.35) showed significant difference between groups. CONCLUSIONS: From the results, it was proved that MAD was an effective treatment option for the OSA patients. Some cephalometric and polysomnographic parameters including posterior lower facial height, apnea index, average oxygen saturation, lowest oxygen saturation, oxygen saturation under 90 %, and oxygen desaturation index could be influencing factors on MAD effect.

Cardiopulmonary coupling analysis: changes before and after treatment with a mandibular advancement device.

PURPOSE: The aim of this study is to evaluate the changes of sleep quality in patients using a mandibular advancement device (MAD) for obstructive sleep apnea (OSA) based upon cardiopulmonary coupling (CPC). METHODS: A total of 52 patients (mean age 53.7±9.6 years, range 33-74 years) were included in this study. Of them, there were 47 males (90.4%). All subjects were diagnosed with OSA after in-laboratory full-night polysomnography and reevaluated after 3-month use of a MAD. At baseline, apnea-hypopnea index (AHI) was 33.6±17.0, Epworth sleepiness scale was 10.5±4.8, and Pittsburgh sleep quality index was 5.8±2.8. The CPC parameters were extracted from single-lead electrocardiography of polysomnography. We compared CPC parameters at baseline with those after 3-month use of a MAD. RESULTS: All respiratory indices improved with the use of MAD. However, there were no differences in the sleep architectures except N3 sleep (3.7±4.3 to 6.9±6.4%, p<0.001). The CPC parameters showed a significant improvement with the use of MAD. Low-frequency coupling (59.5±16.1 to 47.7±14.8%, p<0.001) and elevated low-frequency coupling (44.6±18.4 to 32.6±15.7%, p<0.001) significantly decreased. High-frequency coupling (28.6±16.0 to 36.5±15.7%, p=0.004) and very low frequency coupling (11.7±7.2 to 15.3±6.6%, p=0.028) significantly increased. The change of AHI significantly correlated with changes of the CPC parameters: negatively correlated with high-frequency coupling change (r=-0.572, p<0.001) and positively correlated with low-frequency and elevated low-frequency coupling changes (r=0.604 and 0.497, respectively; p<0.001 in both). However, the changes of Epworth sleepiness scale and Pittsburgh sleep quality index after MAD therapy showed no significant correlation with the changes in the CPC parameters. CONCLUSIONS: To our knowledge, this is the first study to evaluate the quality of sleep in patients using a MAD for their OSA based upon CPC analysis. Low-frequency coupling decreased as AHI improved, while high-frequency coupling increased as AHI improved. The CPC parameters showed that the sleep quality was improved by MAD therapy.