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Objective: Occupational stress and the serotonin receptor (5-HTR) play a key role in the regulation of sleep quality. Previous studies on the relationship between work-related stress, 5-HTR2A polymorphism, and sleep complaints found that 5-HTR2A modulates the response of the hypothalamic-pituitary-adrenal axis to stress and the maintenance of circadian rhythm. However, the effect of 5-HTR2A polymorphism and occupational stress on sleep quality has not been reported. The present study investigated the effects of 5-HTR2A genotypes, occupational stress, and gene-environment interactions on the sleep quality.Methods: Using a three-stage stratified sampling method, 1181 participants were recruited. Then, according to the study exclusion criteria, 810 subjects remained eligible. Finally, because some of subjects did not agree to being involved in this study, 700 workers were included. Of 700 workers finally included in the study, 251 had poor sleep quality based on the Pittsburgh Sleep Quality Index. The 5-HTR2A genotypes were determined with the SNaPshot single nucleotide polymorphism assay. Occupational stress was assessed with the Occupational Stress Inventory-Revised questionnaire.Results: 5-HTR2A genotype was significantly associated with sleep quality. The CT genotype of rs1923884 was detected at a higher frequency among individuals with low sleep efficiency; the AA genotype of rs2070040 was associated with long sleep duration and more daytime dysfunction; and the CC genotype of rs6313 was linked to long sleep latency and duration and poor sleep quality. A high level of occupational stress was linked to higher risk of poor sleep quality than low or moderate levels (odds ratio [OR] = 12.55, 95% confidence interval [CI]: 7.02-22.43). A crossover analysis demonstrated an occupational stress × 5-HTR2A interaction. Compared to participants with low occupational stress and a CT/TT genotype, those with high occupational stress and a CC genotype had a higher risk of poor sleep quality (OR = 7.93, 95% CI: 3.41-18.43), whereas those with low occupational stress and a CC genotype had a lower risk of poor sleep quality (OR = 1.53, 95% CI: 1.07-2.19).Conclusions: Occupational stress and 5-HTR2A genotypes in workers are associated both independently and in combination with increased risk of poor sleep quality. Our data provide evidence that occupational stress contributes to the risk of poor sleep quality through interaction with 5-HTR2A gene polymorphism. [ABSTRACT FROM AUTHOR]

Objective: Sudden infant death syndrome (SIDS) is a major cause of death among children aged <1 year. Campaigns to educate physicians have been effective to reduce its incidence. We assessed the knowledge of Brazilian pediatricians' regarding risk factors for SIDS, their familiarity with the first Brazilian SIDS campaign launched in 2009, and self-reported changes in practices following this campaign.Methods: Active members of the Brazilian Society for Pediatrics who had been in practice for at least two years at the time of the campaign were invited. Pediatricians answered an online survey including eight multiple-choice questions and one open-ended question. Invitees were chosen by chance draw to reflect the geographic distribution of pediatricians in the five regions of the country.Results: The survey was answered by 1654 pediatricians (mean [SD] age: 46 [11.5] years; mean [SD] professional practice time: 20.2 [11.52] years). Bedding items (77.7%), prone sleeping position (72.9%), bed sharing (66.3%), and smoking (59.2%) were recognized as risk factors for SIDS. Most pediatricians (88.2%) were familiar with the campaign, and 84.7% were aware of the current recommendation of supine sleeping position to prevent SIDS. The effectiveness of the first Brazilian SIDS campaign could be measured by a change in practice; before the campaign, 67.5% recommended lateral position and 23.1% the supine, and after the campaign, 76.2% recommended supine and 10.4% lateral. However, 12.8% still recommend prone position.Conclusions: The majority of pediatricians changed their advice to parents after the educational campaign and became familiar with risk factors for SIDS. Continuous educational campaigns focusing on physicians resistant to changing practices should be provided. [ABSTRACT FROM AUTHOR]

Study Objectives: The objective of this study was to investigate whether nightmare (NM) sufferers exhibit an abnormal network of emotional semantic associations as measured by a recently developed, rapid eye movement (REM) sleep-sensitive, associational breadth (AB) task.Design: NM sufferers were compared to healthy controls (CTL) for their performance on an emotional AB task containing positive and negative cue words both before and after a nap with REM sleep. AB was assessed in both a priming condition, where cue words were explicitly memorized before sleep, and a non-priming condition, where cue words were not memorized. Performance was assessed again 1 week later.Setting: The study was conducted in a sleep laboratory with polysomnographic recording at the Hôpital du Sacré-Coeur de MontréalParticipants: Twenty-eight participants between the ages of 18 and 35 years (Mage = 23.3 ± 3.4) were included in the study.Measurements and Results: The NM group scored higher than the CTL group on both positive and negative AB, with group differences persisting at the 1-week retest. However, the two groups did not differ as expected in the AB priming effect following REM sleep. Both groups showed decreased REM sleep-related AB priming for negative cue words and increased AB priming for positive cue words. However, the NM group maintained these effects 1 week later, whereas the CTL group did not.Conclusions: NM sufferers may access broader than normal emotional semantic networks in the wake state, a difference that may lead to this group being perceived as more creative. The fact that the AB priming effect is maintained at the 1-week retest for NM sufferers suggests that the presence of frequent NMs may alter REM sleep-dependent emotional processes over time. [ABSTRACT FROM AUTHOR]

Objectives: Acoustic stimulation synchronized to slow waves (SWs) can enhance these sleep features and facilitate memory consolidation during nocturnal sleep. Here, we investigated whether a similar benefit could be accrued following stimulation during an afternoon nap. We also evaluated the event-related dynamics of associated EEG spectral changes and their correlation with memory performance.Methods: Sixteen healthy young adults (mean age: 22 ± 1.4 years; nine males) were studied under two conditions: stimulation (STIM) and no stimulation (SHAM), in counter-balanced order. In the STIM condition, acoustic stimulation was delivered using blocks of five tones, each phase-locked to the SW up-state during a 90-min nap opportunity. In the SHAM condition, these time points were marked, but tones were not presented. Prior to the nap, participants learned 40 semantically related word pairs and immediate recall was tested. A delayed recall test was administered 45 min after awakening.Results: Compared to the SHAM condition, acoustic stimulation increased SW amplitude, theta, and fast spindle activity and attenuated the forgetting of word pairs (p values < 0.05).Conclusion: Phase-locked acoustic stimulation can promote sleep-dependent declarative memory during a daytime nap. This can be achieved by stimulation in Stage 2 and SWS without a requirement for high-amplitude slow wave detection. [ABSTRACT FROM AUTHOR]

Study Objectives: This study involves the analysis of a secondary outcome of a trial examining whether cognitive behavior therapy for insomnia (CBT-I), a wake-promoting medication (armodafinil), or both results in greater improvement in prospectively assessed sleep continuity and daytime sleepiness than a placebo-alone group among a heterogeneous group of cancer survivors. Whether or not armodafinil alone, and/or when combined with CBT-I, affected adherence with CBT-I was evaluated.Design: This study is a randomized, placebo-controlled, clinical trial.Setting: This study was conducted at two northeastern academic medical centers.Participants: Eighty-eight cancer survivors with chronic insomnia were recruited between October 2008 and November 2012. Participants were assigned to one of four conditions: 1) CBT-I and placebo (CBT-I+P); 2) CBT-I and armodafinil (CBT-I + A); 2) armodafinil alone (ARM); or 4) placebo alone (PLA).Interventions: CBT-I was delivered in seven weekly individual therapy sessions (three in person, four via telephone). The armodafinil dosage was 50 mg BID.Measurements and Results: Sleep continuity was measured with daily sleep diaries assessing sleep latency (SL), wake after sleep onset (WASO), and total sleep time (TST). The Epworth Sleepiness Scale (ESS) measured daytime sleepiness. Compared to the PLA group, the CBT-I+P and CBT-I+A groups reported a significant reduction in SL with effect sizes of 0.67 and 0.58, respectively. A significant reduction was observed in WASO in the CBT-I+A group with an effect size of 0.64. An increasing trend of TST was observed in the CBT-I+P, CBT-I+A, and PLA groups, but not in the ARM group. No statistically significant reductions in daytime sleepiness (ESS) were observed for any of the groups.Conclusion: CBT-I alone and in combination with armodafinil caused significant improvement in sleep continuity. The addition of armodafinil did not appear to improve daytime sleepiness or enhance adherence to CBT-I. [ABSTRACT FROM AUTHOR]

Objective: Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular disease because of its associated autonomic nervous and vascular regulatory dysfunctions. We tested the hypothesis that the multiscale entropy (MSE) approach to heart rate variability analysis may be used for evaluating OSA severity through simultaneous assessment of these abnormalities.Methods: A total of 147 subjects were divided into four groups according to apnea-hypopnea index (AHI) from polysomnography (PSG): Snoring without OSA (5 > AHI, n = 31), mild (5 ≤ AHI < 15, n = 31), moderate (15 ≤ AHI < 30, n = 41), and severe (AHI ≥ 30, n = 44) OSA. Of the patients, 41 receiving continuous positive airway pressure (CPAP) treatment were included for comparison. For each subject, two segments of electrocardiographic (ECG) signals (both at stage N2) were used for R-R interval (RRI) analysis, including a 10-minute recording 10 minutes after falling asleep (ie, early phase) and another 10-minute segment at 3 hours (ie, late phase). Heart rate variability as reflected in changes in RRI between the two segments was assessed with small-scale multiscale entropy index (MEISS, sum of sample entropy from time scale from 1 to 5) and large-scale multiscale entropy index (MEILS, scale from 6 to 10).Results: Increase in MEILS in the late phase of sleep was noted in both the normal snoring and CPAP groups (P <0.01). Although the moderate OSA group exhibited MEISS drop in the late phase (P < 0.02), both MEISS and MEILS decreased in the late phase in the severe OSA group (P < 0.001, P < 0.02). However, no differences were noted in mild OSA subjects in both parameters.Conclusion: The results demonstrated significant severity-dependent deterioration in autonomic and vascular regulatory function in patients with OSA as reflected in the reductions in MEISS and MEILS, respectively, and notable improvement after CPAP treatment. The MEI obtainable through PSG may indicate not only OSA severity and physiological status but also therapeutic outcome for OSA patients. [ABSTRACT FROM AUTHOR]

Learning leads to rapid microstructural changes in gray (GM) and white (WM) matter. Do these changes continue to accumulate if task training continues, and can they be reverted by sleep? We addressed these questions by combining structural and diffusion weighted MRI and high-density EEG in 16 subjects studied during the physiological sleep/wake cycle, after 12 h and 24 h of intense practice in two different tasks, and after post-training sleep. Compared to baseline wake, 12 h of training led to a decline in cortical mean diffusivity. The decrease became even more significant after 24 h of task practice combined with sleep deprivation. Prolonged practice also resulted in decreased ventricular volume and increased GM and WM subcortical volumes. All changes reverted after recovery sleep. Moreover, these structural alterations predicted cognitive performance at the individual level, suggesting that sleep's ability to counteract performance deficits is linked to its effects on the brain microstructure. The cellular mechanisms that account for the structural effects of sleep are unknown, but they may be linked to its role in promoting the production of cerebrospinal fluid and the decrease in synapse size and strength, as well as to its recently discovered ability to enhance the extracellular space and the clearance of brain metabolites. [ABSTRACT FROM AUTHOR]

Although numerous studies have convincingly demonstrated that sleep plays a critical role in motor sequence learning (MSL) consolidation, the specific contribution of the different sleep stages in this type of memory consolidation is still contentious. To probe the role of stage 2 non-REM sleep (NREM2) in this process, we used a conditioning protocol in three different groups of participants who either received an odor during initial training on a motor sequence learning task and were re-exposed to this odor during different sleep stages of the post-training night (i.e., NREM2 sleep [Cond-NREM2], REM sleep [Cond-REM], or were not conditioned during learning but exposed to the odor during NREM2 [NoCond]). Results show that the Cond-NREM2 group had significantly higher gains in performance at retest than both the Cond-REM and NoCond groups. Also, only the Cond-NREM2 group yielded significant changes in sleep spindle characteristics during cueing. Finally, we found that a change in frequency of sleep spindles during cued-memory reactivation mediated the relationship between the experimental groups and gains in performance the next day. These findings strongly suggest that cued-memory reactivation during NREM2 sleep triggers an increase in sleep spindle activity that is then related to the consolidation of motor sequence memories. [ABSTRACT FROM AUTHOR]

Background: Obstructive sleep apnea (OSA) is severely affected by visceral adiposity (VA) that correlates to another disorder-metabolic syndrome (MetS). However, little is known concerning the relation of visceral adiposity index (VAI)-a novel and simple indicator of VA, with OSA and MetS. The objective of the study was to analyze the association of VAI with both disorders and applicability to identify OSA patients at risk of MetS.Methods: Consecutive individuals undergoing polysomnography and biochemical tests were enrolled, and differences in all subjects grouped by apnea-hypopnea index (AHI) were analyzed. Spearman correlation was performed for assessing the relationship between VAI, OSA-related indices and metabolic score-total number of the positive diagnostic criteria of MetS. Receiver operating characteristic (ROC) curve was conducted to obtain a cut-off value of VAI for predicting incident MetS by sex. Then, the risk of MetS in OSA patients according to the cut-offs was attained by logistic regression.Results: A total of 411 individuals were enrolled. Of whom, 361 subjects were diagnosed OSA (mild in 67 patients, moderate in 89 and severe in 205, respectively). A significant increasing trend based on AHI was observed in the variables of blood pressure, triglycerides, fasting glucose, incident MetS, metabolic score and VAI (all p < 0.05). Irrespective of gender, VAI was all significantly correlated with PSG characteristics as AHI, mean nocturnal oxygen saturation, the lowest oxygen saturation, metabolic score(all p < 0.05). A VAI of 2.282, 2.105, 2.511 (for all subjects, males and females, separately) were calculated to determine the occurrence of MetS. According to the cut-offs, OSA patients tended to suffer from greater risk in MetS (odds ratio [OR] = 10.237, p = 0.000; OR = 13.556, p = 0.000; OR = 21.458, p = 0.000).Conclusions: The present study suggested that VAI was significantly associated with MetS and OSA. As a simple and alternative approach obtained in everyday practice, it may offer a powerful tool to identify patients with OSA at risk of MetS. [ABSTRACT FROM AUTHOR]

Background: Sleep disordered breathing (SDB) such as sleep apnea is associated with cardiovascular disease in the general population. However, little is known about the cardiovascular risks of SDB in patients with end-stage renal disease (ESRD).Methods: We identified Medicare fee-for-service beneficiaries aged ≥67 years initiating dialysis between 2004 and 2009. Outcomes of interest included all-cause mortality, incident myocardial infarction, ischemic stroke, and atrial fibrillation. We compared patients with and without diagnosed SDB using Cox proportional hazards regression.Results: Between 2004 and 2009, 184,217 older patients developed ESRD, of whom 15,121 (8.2 %) were previously diagnosed with SDB. Patients diagnosed with SDB were younger, more likely to be male and Caucasian, less Medicaid eligible, had more non-Nephrology clinic visits, higher body mass index, and more comorbidity. In analyses adjusting for demographics and BMI, diagnosed SDB was associated with higher risk of death and atrial fibrillation, but not associated with myocardial infarction or ischemic stroke risk. After further adjustment for all baseline characteristics, diagnosed SDB was associated with slightly lower risks of death (hazard ratio [HR]: 0.93, 95 % confidence interval [CI]: 0.91-0.96), myocardial infarction (HR: 0.92, CI: 0.87-0.98), and ischemic stroke (HR: 0.90, 95 % CI: 0.82-0.98), and not associated with atrial fibrillation (HR: 1.02, CI: 0.98-1.07).Conclusions: In older patients initiating dialysis in the U.S., diagnosed SDB was weakly associated with lower risks of death and important cardiovascular outcomes, thus adding to the list of established risk factors that are paradoxically associated with cardiovascular outcomes in the ESRD population. [ABSTRACT FROM AUTHOR]

Cholinergic projections from the basal forebrain and brainstem are thought to play important roles in rapid eye movement (REM) sleep and arousal. Using transgenic mice in which channelrhdopsin-2 is selectively expressed in cholinergic neurons, we show that optical stimulation of cholinergic inputs to the thalamic reticular nucleus (TRN) activates local GABAergic neurons to promote sleep and protect non-rapid eye movement (NREM) sleep. It does not affect REM sleep. Instead, direct activation of cholinergic input to the TRN shortens the time to sleep onset and generates spindle oscillations that correlate with NREM sleep. It does so by evoking excitatory postsynaptic currents via α7-containing nicotinic acetylcholine receptors and inducing bursts of action potentials in local GABAergic neurons. These findings stand in sharp contrast to previous reports of cholinergic activity driving arousal. Our results provide new insight into the mechanisms controlling sleep. [ABSTRACT FROM AUTHOR]

The Ca2+ modulation in the dorsal raphe nucleus ( DRN) plays an important role in sleep-wake regulation. Calmodulin-dependent kinase II (Ca MKII) is an important signal-transducing molecule that is activated by Ca2+. This study investigated the effects of intracellular Ca2+/Ca MKII signaling in the DRN on sleep-wake states in rats. Maximum and minimum Ca MKII phosphorylation was detected at Zeitgeber time 21 ( ZT 21; wakefulness state) and ZT 3 (sleep state), respectively, across the light-dark rhythm in the DRN in rats. Six-hour sleep deprivation significantly reduced Ca MKII phosphorylation in the DRN. Microinjection of the CAMKII activation inhibitor KN-93 (5 or 10 nmol) into the DRN suppressed wakefulness and enhanced rapid-eye-movement sleep ( REMS) and non- REM sleep ( NREMS). Application of a high dose of KN-93 (10 nmol) increased slow-wave sleep ( SWS) time, SWS bouts, the mean duration of SWS, the percentage of SWS relative to total sleep, and delta power density during NREMS. Microinjection of CaCl2 (50 nmol) in the DRN increased Ca MKII phosphorylation and decreased NREMS, SWS, and REMS. KN-93 abolished the inhibitory effects of CaCl2 on NREMS, SWS, and REMS. These data indicate a novel wake-promoting and sleep-suppressing role for the Ca2+/Ca MKII signaling pathway in DRN neurons. [ABSTRACT FROM AUTHOR]

Background: Theoretical models of Bipolar Disorder (BD) highlight that sleep disturbances may be a marker of underlying circadian dysregulation. However, few studies of sleep in BD have reported on the most prevalent circadian sleep abnormality, namely Delayed Sleep Phase (DSP).Methods: A cross-sectional study of 404 adults with BD who met published clinical criteria for insomnia, hypersomnia or DSP, and who had previously participated in a study of sleep in BD using a comprehensive structured interview assessment.Results: About 10% of BD cases with a sleep problem met criteria for a DSP profile. The DSP group was younger and had a higher mean Body Mass Index (BMI) than the other groups. Also, DSP cases were significantly more likely to be prescribed mood stabilizers and antidepressant than insomnia cases. An exploratory analysis of selected symptom item ratings indicated that DSP was significantly more likely to be associated with impaired energy and activity levels.Limitations: The cross-sectional design precludes examination of longitudinal changes. DSP is identified by sleep profile, not by diagnostic criteria or objective sleep records such as actigraphy. The study uses data from a previous study to identify and examine the DSP group.Conclusions: The DSP group identified in this study can be differentiated from hypersomnia and insomnia groups on the basis of clinical and demographic features. The association of DSP with younger age, higher BMI and impaired energy and activity also suggest that this clinical profile may be a good proxy for underlying circadian dysregulation. [ABSTRACT FROM AUTHOR]

The transition from wakefulness into sleep is accompanied by modified activity in the brain's thalamocortical network. Sleep-related decreases in thalamocortical functional connectivity (FC) have previously been reported, but the extent to which these changes differ between thalamocortical pathways, and patterns of intra-thalamic FC during sleep remain untested. To non-invasively investigate thalamocortical and intra-thalamic FC as a function of sleep stage we recorded simultaneous EEG–fMRI data in 13 healthy participants during their descent into light sleep. Visual scoring of EEG data permitted sleep staging. We derived a functional thalamic parcellation during wakefulness by computing seed-based FC, measured between thalamic voxels and a set of pre-defined cortical regions. Sleep differentially affected FC between these distinct thalamic subdivisions and their associated cortical projections, with significant increases in FC during sleep restricted to sensorimotor connections. In contrast, intra-thalamic FC, both within and between functional thalamic subdivisions, showed significant increases with advancement into sleep. This work demonstrates the complexity and state-specific nature of functional thalamic relationships – both with the cortex and internally – over the sleep/wake cycle, and further highlights the importance of a thalamocortical focus in the study of sleep mechanisms. [ABSTRACT FROM AUTHOR]

Objective Endogenous neurosteroids that potentiate the gamma-aminobutyric acid type A (GABAA) receptor are thought to enhance the generation of sleep spindles. This study tested the hypothesis that the 5α-reductase inhibitor finasteride, an agent associated with reductions in neurosteroids, would be associated with reduced sleep spindles in men referred for polysomnography. Methods Spectral analysis and spindle waveform detection were performed on electroencephalographic (EEG) sleep data in the 11-16 Hz sigma band, as well as several subranges, from 27 men taking finasteride and 27 matched comparison patients (ages 18 to 81 years). Results No significant differences between groups were observed for spectral power or sleep spindle morphology measures, including spindle density, amplitude, duration, and integrated spindle activity. Conclusions Contrary to our hypothesis, these findings demonstrate that finasteride is not associated with alterations in sleep spindle range activity or spindle morphology parameters. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Risk factors for obstructive sleep apnea (OSA) are common in people with schizophrenia. Identification and treatment of OSA may improve physical health in this population; however there are no guidelines to inform screening and management.Objectives: Systematic review to determine, in people with schizophrenia and related disorders: the prevalence of OSA; the prevalence of OSA compared to general population controls; the physical and psychiatric correlates of OSA, associations between antipsychotic medications and OSA; the impact of treatment of OSA on psychiatric and physical health; and the diagnostic validity of OSA screening tools.Data Sources: Medline, EMBASE, ISI Web of Science and PsycINFO electronic databases. Cohort, case-control and cross-sectional studies and RCTs reporting on prevalence of OSA in subjects with schizophrenia and related disorders were reviewed.Results: The prevalence of OSA varied between 1.6% and 52%. The prevalence of OSA was similar between people with schizophrenia and population controls in two studies. Diagnosis of OSA was associated with larger neck circumference, BMI>25, male sex and age>50years. There were no data on physical or psychiatric outcomes following treatment of OSA. The diagnostic utility of OSA screening tools had not been investigated.Conclusion: OSA may be prevalent and potentially under-recognized in people with schizophrenia. Further research is required to determine utility of OSA screening tools, the relationships between antipsychotic medications and OSA and any benefits of treating OSA. We propose a strategy for the identification of OSA in people with schizophrenia and related disorders. [ABSTRACT FROM AUTHOR]

This study investigated the feasibility, safety and efficacy of Coblation endoscopic lingual lightening (CELL) surgery for obstructive sleep apnea (OSA). This study was a retrospective case series in a tertiary referral sleep center. Twenty-five adults with moderate to severe OSA and determined to have retropalatal and tongue base obstruction based on Friedman tongue position III and fiberoptic endoscopy underwent CELL in combination with modified uvulopalatopharyngoplasty, known as relocation pharyngoplasty. CELL involves transoral resection of tongue base muscle tissue and lingual tonsil using Coblation under endoscopic guidance. The mean operation time for CELL was 42.6 ± 13.7 min. Total blood loss for CELL plus relocation pharyngoplasty was <50 ml in all patients. Mean postoperative pain score (sum of total pain scores/sum of total hospitalization day, visual analog scale, 0-10) was 2.6 ± 0.6. Postoperative bleeding and taste disturbance extending beyond 3 months occurred in one patient (4 %) individually. No patients reported tongue weakness or speech dysfunction. Epworth sleepiness scale improved from 9.6 ± 4.9 to 7.5 ± 4.3 ( p = 0.023). Apnea-hypopnea index decreased from 45.7 ± 21.7 to 12.8 ± 8.2 events/hour ( p < 0.001) 6 months after surgery. The overall response rate was 80 %. CELL is feasible, safe and effective in treating tongue base obstruction in OSA patients who underwent simultaneous relocation pharyngoplasty. [ABSTRACT FROM AUTHOR]

Background: The brain's continuous neural activity during sleep can be monitored by electroencephalogram (EEG) signals. The EEG wave pattern and frequency vary during five stages of sleep. These subtle variations in sleep EEG signals cannot be easily detected through visual inspection. Summary: A range of time, frequency, time-frequency and nonlinear analysis methods can be applied to understand the complex physiological signals and their chaotic behavior. This paper presents a comprehensive comparative review and analysis of 29 nonlinear dynamics measures for EEG-based sleep stage detection. Key Messages: The characteristic ranges of these features are reported for the five different sleep stages. All nonlinear measures produce clinically significant results, that is, they can discriminate the individual sleep stages. Feature ranking based on the statistical F-value, however, shows that the third order cumulant of higher order spectra yields the most discriminative result. The distinct value ranges for each sleep stage and the discriminative power of the features can be used for sleep disorder diagnosis, treatment monitoring, and drug efficacy assessment. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Sleep participates in the regulation of body weight. The amount of sleep and synchronization of the biological clock are both necessary to achieve the energy balance and the secretion of hormones that contribute to weight regulation. In this review, we first reconsider what normal physiological sleep is and what the normative values of sleep are in the general population. Second, we explain how the biological clock regulates the hormones that may be involved in weight control. Third, we provide some recent data on how sleep may be disturbed by sleep disorders or reduced by sleep debt with consequences on weight. Finally, we explore the relationships between sleep debt and obesity. [ABSTRACT FROM AUTHOR]

Genetic underpinnings for sleep disorders in humans remain poorly identified, investigated and understood. This is due to the inherent complexity of sleep and a disruption of normal sleep parameters in a number of neurological disorders. On the other hand, there have been steady and remarkable developments in the investigation of sleep using model organisms such as Drosophila . These studies have illuminated conserved genetic pathways, neural circuits and intra-cellular signaling modules in the regulation of sleep. Additionally, work in model systems is beginning to clarify the role of the circadian clock and basal sleep need in this process. There have also been initial efforts to directly model sleep disorders in flies in a few instances where a genetic basis has been suspected. Here, we discuss the opportunities and limitations of studying sleep disorders in Drosophila and propose that a greater convergence of basic sleep research in model organisms and human genetics should catalyze better understanding of sleep disorders and generate viable therapeutic options. [ABSTRACT FROM AUTHOR]

Sleep is disrupted during active use of methamphetamine (MA), during withdrawal from the drug, and during abstinence from its use. However, relatively little is known about possible mediatory functions of disrupted sleep in the emergence, manifestation, and maintenance of cognitive and affective symptoms of MA abuse. We hypothesise that sleep functions as a mediator for stimulant drug effects. Specifically, we propose that objectively-measured sleep parameters can be used to explain some of the variability in the experience and presentation of memory deficits and emotion dysregulation in MA abusers. After describing how important healthy sleep is to unimpaired cognitive and affective functioning, we review literature describing how sleep is disrupted in MA abuse. Then, we provide a conceptual framework for our hypothesis by explaining the relationship between MA abuse, sleep disruption, memory deficits, emotion dysregulation, and changes in reward-related brain networks. We conclude by discussing implications of the hypothesis for research and treatment. [ABSTRACT FROM AUTHOR]

Electroencephalography (EEG) is typically viewed through the lens of spectral analysis. Recently, multiple lines of evidence have demonstrated that the underlying neuronal dynamics are characterized by scale-free avalanches. These results suggest that techniques from statistical physics may be used to analyze EEG signals. We utilized a publicly available database of fourteen subjects with waking and sleep stage 2 EEG tracings per subject, and observe that power-law dynamics of critical-state neuronal avalanches are not sufficient to fully describe essential features of EEG signals. We hypothesized that this could reflect the phenomenon of discrete scale invariance (DSI) in EEG large voltage deflections (LVDs) as being more prominent in waking consciousness. We isolated LVDs, and analyzed logarithmically transformed LVD size probability density functions (PDF) to assess for DSI. We find evidence of increased DSI in waking, as opposed to sleep stage 2 consciousness. We also show that the signatures of DSI are specific for EEG LVDs, and not a general feature of fractal simulations with similar statistical properties to EEG. Removing only LVDs from waking EEG produces a reduction in power in the alpha and beta frequency bands. These findings may represent a new insight into the understanding of the cortical dynamics underlying consciousness. [ABSTRACT FROM AUTHOR]

Objectives We determined whether sleep hygiene is directly related to mood and quality of life (QoL) in people with epilepsy and, if not, documented the indirect effects of sleep hygiene through sleep quality. Methods Data were collected from 150 adults with epilepsy. The Sleep Hygiene Index (SHI), Quality of Life in Epilepsy—10 (QOLIE-10), Hospital Anxiety and Depression Scale (HADS), Sleep Problems Index—2 (SPI-2) of the Medical Outcomes Study—Sleep Scale, and Epworth Sleepiness Scale (ESS) were used. To determine the direct and indirect associations between SHI, mood, and QoL, multiple linear regression analyses and the Sobel test were performed. Results Inadequate sleep hygiene behaviors were answered affirmatively by ≥ 15% of the participants represented by 6 out of 13 items of the SHI. A younger age was independently related to higher SHI scores (p = 0.013). The higher SHI scores were directly related to lower QoL independent of sleep quality, anxiety, and depressive symptoms (p < 0.05) but not independently related to anxiety and depressive symptoms. The Sobel test confirmed that the SHI scores were associated with anxiety and depressive symptoms through sleep quality (p < 0.001). Conclusions Inadequate sleep hygiene is independently related to low QoL but indirectly related to anxiety and depressive symptoms through sleep quality. Patients of a younger age are at risk of poorer sleep hygiene. [ABSTRACT FROM AUTHOR]

Rationale Impaired consciousness during seizures may be mediated by ictal propagation to the thalamus. Functions of individual thalamic nuclei with respect to consciousness, however, are largely unknown. The dorsomedial (DM) nucleus of the thalamus likely plays a role in arousal and cognition. We propose that alterations of firing patterns within the DM nucleus contribute to impaired arousal during focal seizures. Methods Electroencephalograph data were collected from electrodes within the left DM thalamus and midcingulate cortex (MCC) in a patient undergoing seizure monitoring. Spectral power was computed across ictal states (preictal, ictal, and postictal) and level of consciousness (stupor/sleep vs. awake) in the DM nucleus and MCC. Results Eighty-seven seizures of multifocal left frontal and temporal onsets were analyzed, characterized by loss of consciousness. At baseline, the left DM nucleus demonstrated rhythmic bursts of gamma activity, most frequently and with greatest amplitude during wakefulness. This activity ceased as ictal discharges spread to the MCC, and consciousness was impaired, and it recurred at the end of each seizure as awareness was regained. The analysis of gamma (30–40 Hz) power demonstrated that when seizures occurred during wakefulness, there was lower DM ictal power (p < 0.0001) and higher DM postictal power (p < 0.0001) relative to the preictal epoch. This spectral pattern was not evident within the MCC or when seizures occurred during sleep. Conclusions Data revealed a characteristic pattern of DM gamma bursts during wakefulness, which disappeared during partial seizures associated with impaired consciousness. The findings are consistent with studies suggesting that the DM nucleus participates in cognition and arousal. [ABSTRACT FROM AUTHOR]

Psychiatric disorders and obstructive sleep apnea (OSA) are often comorbid. However, there is limited information on the impact of psychotropic medications on OSA symptoms, on how to manage psychiatric pharmacotherapy in patients presenting with OSA, or on the effectiveness and challenges of OSA treatments in patients with comorbid mental illness. As such, the objective of this article is to provide an overview of some epidemiological aspects of OSA and treatment considerations in the management of OSA in individuals with comorbid psychiatric disorders. Predefined keywords were used to search for relevant literature in electronic databases. Data show that OSA is particularly prevalent in patients with psychiatric disorders. The medical care that patients with these comorbidities require can be challenging, as some of the psychiatric medications used by these patients may exacerbate OSA symptoms. As such, continuous positive airway pressure continues to be the first-line treatment, even in patients with psychiatric comorbidity. However, more controlled studies are required, particularly to determine continuous positive airway pressure compliance in patients with mental illness, the impact of treating OSA on psychiatric symptoms, and the impact of the use of psychotropic medications on OSA symptoms. [ABSTRACT FROM AUTHOR]

In recent years, evidence has emerged for a bidirectional relationship between sleep and neurological and psychiatric disorders. First, sleep−wake disorders ( SWDs) are very common and may be the first/main manifestation of underlying neurological and psychiatric disorders. Secondly, SWDs may represent an independent risk factor for neuropsychiatric morbidities. Thirdly, sleep−wake function ( SWF) may influence the course and outcome of neurological and psychiatric disorders. This review summarizes the most important research and clinical findings in the fields of neuropsychiatric sleep and circadian research and medicine, and discusses the promise they bear for the next decade. The findings herein summarize discussions conducted in a workshop with 26 European experts in these fields, and formulate specific future priorities for clinical practice and translational research. More generally, the conclusion emerging from this workshop is the recognition of a tremendous opportunity offered by our knowledge of SWF and SWDs that has unfortunately not yet entered as an important key factor in clinical practice, particularly in Europe. Strengthening pre-graduate and postgraduate teaching, creating academic multidisciplinary sleep−wake centres and simplifying diagnostic approaches of SWDs coupled with targeted treatment strategies yield enormous clinical benefits for these diseases. [ABSTRACT FROM AUTHOR]

Many types of positive airway pressure (PAP) devices are used to treat sleepdisordered breathing including obstructive sleep apnea, central sleep apnea, and sleep-related hypoventilation. These include continuous PAP, autoadjusting CPAP, bilevel PAP, adaptive servoventilation, and volume-assured pressure support. Noninvasive PAP has significant leak by design, which these devices adjust for in different manners. Algorithms to provide pressure, detect events, and respond to events vary greatly between the types of devices, and vary among the same category between companies and different models by the same company. Many devices include features designed to improve effectiveness and patient comfort. Data collection systems can track compliance, pressure, leak, and efficacy. Understanding how each device works allows the clinician to better select the best device and settings for a given patient. This paper reviews PAP devices, including their algorithms, settings, and features. [ABSTRACT FROM AUTHOR]

Objective: Sudden infant death syndrome (SIDS) remains the leading cause of death in the postnatal period. Accidental suffocation and strangulation in bed deaths have quadrupled. The American Academy of Pediatrics (AAP) expanded its back to sleep recommendations to include a safe sleep environment. The AAP makes recommendations to healthcare professionals to model safe sleep practices and educate families on SIDS reduction strategies. The dual aims of this project were to develop a safe sleep educational model for our neonatal intensive care unit (NICU), and to increase the percentage of eligible infants in a safe sleep environment. Method: The NICU Safe Sleep policy was revised to include AAP updated recommendations. Educational updates were provided to staff. A safe sleep packet with a video was created for and shared with families. Wearable blankets were implemented. A safe sleep observation checklist was created. Baseline data and post-education random observations data were collected and shared with staff. Results: At baseline, 21% of eligible infants were in a safe sleep environment. After education and reported observation, safe sleep compliance increased to 88%. Conclusions: With formal staff and family education, optional wearable blanket, and data sharing, safe sleep compliance increased and patient safety improved. [ABSTRACT FROM PUBLISHER]

Background: Continuous Positive Airway Pressure (CPAP) remains the reference treatment for moderate to severe forms of the Sleep Apnea/Hypopnea Syndrome (SAHS). Compliance to the treatment appears to be a key factor to improving health status of these patients.Methods: We conducted a multicenter, prospective, randomized, controlled, parallel group trial of standard support completed or not within 3 months of coaching sessions for newly diagnosed SAHS patients starting CPAP therapy. This study has been recorded by AFSSAPS with the RCB number: 2009-A01127-50 and received favourably by the Human Studies Committee in France. The coaching session consisted of 5 sessions of telephone-based counselling by competent staff. The primary outcome was the proportion of patients using CPAP more than 3 h per night for 4 months; the secondary outcome was mean hours of CPAP usage in the 2 groups.Results: Three hundred and seventy-nine patients fulfilled the inclusion criteria and were randomized. The percentage of patients using CPAP more than 3 h per night for 4 months was 65 % for the standard support group and 75 % for the coached group. This difference reached a statistical significance (χ2 = 3.97). The mean CPAP usage was increased in the coached group versus standard group. A difference of 26 min was observed (4 h34+/-2 h17 and 4 h08+/-2 h25 respectively, p = 0.04).Conclusion: This study shows that SAHS patients who benefit from phone coaching are statistically more compliant to CPAP than a standard support group is. A simple phone coaching procedure based on knowledge of the disease and reinforcement messages about treatment benefits helps to improve CPAP adherence in SAHS patients.Trial Registration: NCT02435355. [ABSTRACT FROM AUTHOR]

Spontaneous eye-closures that herald sleep onset become more frequent when we are sleep deprived. Although these are typically associated with decreased responsiveness to external stimuli, it is less clear what occurs in the brain at these transitions to drowsiness and light sleep. To investigate this, task-free fMRI of sleep-deprived participants was acquired. BOLD activity associated with periods of spontaneously occurring eye closures were marked and analyzed. We observed concurrent and extensive hypnagogic co-activation of the extrastriate visual, auditory, and somatosensory cortices as well as the default mode network, consistent with internal sensory activity without external stimulation. Co-activation of fronto-parietal areas known to mediate attentional control could correspond with participants resisting sleep or additional engagement of mental imagery. This constellation of signal changes differed from those elicited by cued eye closures of similar duration and distribution in the same, rested participants. They also differ from signal changes associated with mind-wandering and consolidated light sleep. Concurrent with the observed event-related changes, eye closures elicited additional reduction in functional connectivity within nodes of the DMN and DAN, superposed on already reduced connectivity associated with sleep deprivation. There was concurrent deactivation of the thalamus during eye-closure during the sleep-deprived state but almost similar changes occurred in the well-rested state that may also be relevant. These findings highlight the dynamic shifts in brain activity and connectivity at border between wakefulness and sleep. [ABSTRACT FROM AUTHOR]

Purpose: While fatigue, sleep disturbance, and depression often co-occur in breast cancer patients, treatment efficacy for this symptom cluster is unknown. A systematic review was conducted to determine whether there are specific interventions (ie, medical, pharmacological, behavioral, psychological, and complementary medicine approaches) that are effective in mitigating the fatigue-sleep disturbance-depression symptom cluster in breast cancer patients, using the Rapid Evidence Assessment of the Literature (REAL©) process. Methods: Peer-reviewed literature was searched across multiple databases; from database inception - October 2011, using keywords pre-identified to capture randomized controlled trials (RCT) relevant to the research question. Methodological bias was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) 50 checklist. Confidence in the estimate of effect and assessment of safety were also evaluated across the categories of included interventions via the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) methodology. Results: The initial search yielded 531 citations, of which 41 met the inclusion criteria. Of these, twelve RCTs reported on all three symptoms, and eight of these were able to be included in the GRADE analysis. The remaining 29 RCTs reported on two symptoms. Studies were of mixed quality and many were underpowered. Overall, results suggest that there is: 1) promising evidence for the effectiveness of various treatment types in mitigating sleep disturbance in breast cancer patients; 2) mixed evidence for fatigue; 3) little evidence for treating depression; and 4) no clear evidence that treatment of one symptom results in effective treatment for other symptoms. Conclusion: More high-quality studies are needed to determine the impact of varied treatments in mitigating the fatigue-sleep disturbance-depression symptom cluster in breast cancer patients. Furthermore, we encourage future studies to examine the psychometric and clinical validity of the hypothesized relationship between the symptoms in the fatigue-sleep disturbance- depression symptom cluster. [ABSTRACT FROM AUTHOR]

This is a large cross-sectional study which aimed to investigate comorbidity rate, degree of sleep-related breathing disorder, polysomnigraphically diagnosible rapid eye movement sleep behavior disorder/rapid eye movement sleep without atonia and periodic limb movements during sleep in Japanese drug-naïve patients with narcolepsy-spectrum disorders. A total of 158 consecutive drug naïve patients with narcolepsy with cataplexy, 295 patients with narcolepsy without cataplexy and 395 patients with idiopathic hypersomnia without long sleep time were enrolled. From retrospectively analyzed data of nocturnal polysomnography and multiple sleep latency test, higher rates of periodic limb movements during sleep (> = 15 h-1) (10.2%) and polysomnographically diagnosable rapid eye movement sleep behavior disorder (1.9%) were found in patients with narcolepsy with cataplexy. They had more severe periodic limb movements during sleep especially during rapid eye movement sleep and higher percentages of rapid eye movement sleep without atonia than the other two patient groups. In the present large sample study, Japanese drug naïve patients with narcolepsy with cataplexy showed the highest comorbidity rates of periodic limb movements during sleep, polysomnographically diagnosable rapid eye movement sleep behavior disorder and rapid eye movement sleep without atonia among those with the other narcolepsy-spectrum disorders; the rates were lower than those for Western patients. [ABSTRACT FROM AUTHOR]

Snoring detection is important for diagnosing obstructive sleep apnea syndrome (OSAS) and other respiratory sleep disorders. In general, audio signal processing such as snoring sound analysis uses the frequency characteristics of the signal. Recently, a correlational filter Multilayer Perceptron neural network (f-MLP) has been proposed, which has the first hidden layer of correlational filter operations in frequency domain. It demonstrated a superior classification performance for the pattern sets; of these, frequency information is the dominant feature for classification. The first hidden layer is implemented with the correlational filter operation; its output is the power spectrum of the filter output, while the other layers are the same as the ordinary multilayer Perceptron (o-MLP). By using the back-propagation learning algorithm for the correlational filter layer, f-MLP was able to self-adapt the filter coefficients to produce its output with more discrimination power for classification in the higher layer. In this research, this f-MLP was applied for sleep snoring signal detection. As a result, the f-MLP achieved an average detection rate of 96% for the test patterns, compared to the conventional multilayer neural network that demonstrates an 82% average detection rate. [ABSTRACT FROM AUTHOR]

Objective: We examined the relationship between chronotype and sleep disturbance, and assessed various factors that might be associated with sleep disturbance in Korean firefighters. Methods: Self-administered questionnaires assessing chronotype, depression, alcohol use, posttraumatic stress disorder (PTSD), stress response and sleep quality were examined in 515 firefighters. Results: Evening type firefighters more reported depression, alcohol use, PTSD, stress response and sleep disturbance. Also evening chronotype was the most significant risk factor for poor sleep quality (odds ratio [OR], 4.812; 95% confidence interval [CI], 2.448-9.459), even after controlling for all other variables (OR, 3.996; 95% CI, 1.806-8.841). Conclusion: Chronotype was the factor most strongly associated with sleep disturbance, and therefore should be considered an important variable in sleep quality, particularly in occupations involving stressful activities, such as firefighting. [ABSTRACT FROM AUTHOR]

Sleep Slow Oscillations (SSOs), paradigmatic EEG markers of cortical bistability (alternation between cellular downstates and upstates), and sleep spindles, paradigmatic EEG markers of thalamic rhythm, are two hallmarks of sleeping brain. Selective thalamic lesions are reportedly associated to reductions of spindle activity and its spectrum ~ 14 Hz (sigma), and to alterations of SSO features. This apparent, parallel behavior suggests that thalamo-cortical entrainment favors cortical bistability. Here we investigate temporally-causal associations between thalamic sigma activity and shape, topology, and dynamics of SSOs. We recorded sleep EEG and studied whether spatio-temporal variability of SSO amplitude, negative slope (synchronization in downstate falling) and detection rate are driven by cortical-sigma-activity expression (12–18 Hz), in 3 consecutive 1 s-EEG-epochs preceding each SSO event (Baselines). We analyzed: (i) spatial variability, comparing maps of baseline sigma power and of SSO features, averaged over the first sleep cycle; (ii) event-by-event shape variability, computing for each electrode correlations between baseline sigma power and amplitude/slope of related SSOs; (iii) event-by-event spreading variability, comparing baseline sigma power in electrodes showing an SSO event with the homologous ones, spared by the event. The scalp distribution of baseline sigma power mirrored those of SSO amplitude and slope; event-by-event variability in baseline sigma power was associated with that in SSO amplitude in fronto-central areas; within each SSO event, electrodes involved in cortical bistability presented higher baseline sigma activity than those free of SSO. In conclusion, spatio-temporal variability of thalamocortical entrainment, measured by background sigma activity, is a reliable estimate of the cortical proneness to bistability. [ABSTRACT FROM AUTHOR]

Learning and memory for extinction of conditioned fear is a basic mammalian mechanism for regulating negative emotion. Sleep promotes both the consolidation of memory and the regulation of emotion. Sleep can influence consolidation and modification of memories associated with both fear and its extinction. After brief overviews of the behavior and neural circuitry associated with fear conditioning, extinction learning, and extinction memory in the rodent and human, interactions of sleep with these processes will be examined. Animal and human studies suggest that sleep can serve to consolidate both fear and extinction memory. In humans, sleep also promotes generalization of extinction memory. Time-of-day effects on extinction learning and generalization are also seen. Rapid eye movement (REM) may be a sleep stage of particular importance for the consolidation of both fear and extinction memory as evidenced by selective REM deprivation experiments. REM sleep is accompanied by selective activation of the same limbic structures implicated in the learning and memory of fear and extinction. Preliminary evidence also suggests extinction learning can take place during slow wave sleep. Study of low-level processes such as conditioning, extinction, and habituation may allow sleep effects on emotional memory to be identified and inform study of sleep's effects on more complex, emotionally salient declarative memories. Anxiety disorders are marked by impairments of both sleep and extinction memory. Improving sleep quality may ameliorate anxiety disorders by strengthening naturally acquired extinction. Strategically timed sleep may be used to enhance treatment of anxiety by strengthening therapeutic extinction learned via exposure therapy. [ABSTRACT FROM AUTHOR]

Few studies have examined the effects of total sleep deprivation (TSD) on cognitive performance and brain activation using functional MRI (fMRI) in older adults. The current study examines blood oxygen level-dependent (BOLD) activation in older adults and younger adults during the sustained attention (GO) and response inhibition (NOGO) portions of a GO-NOGO cognitive task following 36 hr of total sleep deprivation. No significant performance differences were observed between the groups on the behavioral outcome measures of total hits and false alarms. Neuroimaging results, however, revealed a significant interaction between age-group and sleep-deprivation status. Specifically, older adults showed greater BOLD activation as compared to younger adults after 36 hours total sleep deprivation in brain regions typically associated with attention and inhibitory processes. These results suggest in order for older adults to perform the GO-NOGO task effectively after sleep deprivation, they rely on compensatory recruitment of brain regions that aide in the maintenance of cognitive performance. [ABSTRACT FROM PUBLISHER]

An important developmental task for adolescents is to become increasingly responsible for their own health behaviors. Establishing healthy sleep routines and controlling media use before bedtime are important for adequate, quality sleep so adolescents are alert during the day and perform well at school. Despite the prevalence of adolescent social media use and the large percentage of computers and cell phones in adolescents' bedrooms, no studies to date have investigated the link between problematic adolescent investment in social networking, their sleep practices, and associated experiences at school. A sample of 1,886 students in Australia aged between 12 and 18 years of age completed self-report data on problematic social networking use, sleep disturbances, sleep quality, and school satisfaction. Structural equation modeling (SEM) substantiated the serial mediation hypothesis: for adolescents, problematic social networking use significantly increased sleep disturbances, which adversely affected perceptions of sleep quality that, in turn, lowered adolescents' appraisals of their school satisfaction. This significant pattern was largely driven by the indirect effect of sleep disturbances. These findings suggest that adolescents are vulnerable to negative consequences from social networking use. Specifically, problematic social networking is associated with poor school experiences, which result from poor sleep habits. Promoting better sleep routines by minimizing sleep disturbances from social media use could improve school experiences for adolescents with enhanced emotional engagement and improved subjective well-being. [ABSTRACT FROM AUTHOR]

Background and aims: The usage of smartphones has increased rapidly in recent years, and this has brought about addiction. The aim of the current study was to investigate the relationship between smartphone use severity and sleep quality, depression, and anxiety in university students. Methods: In total, 319 university students (203 females and 116 males; mean age = 20.5 ± 2.45) were included in the study. Participants were divided into the following three groups: a smartphone non-user group (n = 71, 22.3%), a low smartphone use group (n = 121, 37.9%), and a high smartphone use group (n = 127, 39.8%). All participants were evaluated using the Pittsburgh Sleep Quality Index, Beck Depression Inventory, Beck Anxiety Inventory; moreover, participants other than those in the smartphone non-user group were also assessed with the Smartphone Addiction Scale. Results: The findings revealed that the Smartphone Addiction Scale scores of females were significantly higher than those of males. Depression, anxiety, and daytime dysfunction scores were higher in the high smartphone use group than in the low smartphone use group. Positive correlations were found between the Smartphone Addiction Scale scores and depression levels, anxiety levels, and some sleep quality scores. Conclusion: The results indicate that depression, anxiety, and sleep quality may be associated with smartphone overuse. Such overuse may lead to depression and/or anxiety, which can in turn result in sleep problems. University students with high depression and anxiety scores should be carefully monitored for smartphone addiction. [ABSTRACT FROM AUTHOR]

This study investigates the extent to which sleep characteristics serve as predictor variables for inflammatory, hypothalamic-pituitary-adrenal and autonomic systems markers. Twenty-nine participants with a diagnosis of insomnia disorder based on the Diagnostic Statistical Manual of Mental Disorders, Fifth Edition (age 25.3 ± 1.6 years, insomnia duration 6.6 ± 0.8 years) and 19 healthy control sleepers (age 25.4 ± 1.4 years) underwent a 2-week at-home evaluation keeping a sleep diary and wearing an actigraph, followed by a visit to the Research Center to measure blood pressure, and collect blood and urine samples. The actigraphy- and diary-based variables of sleep duration, sleep-onset latency, wake after sleep onset and sleep fragmentation/number of night-time awakenings were averaged and entered as dependent variables in regression analyses. Composite scores were calculated for the autonomic (blood pressure, norepinephrine), inflammatory (monocyte counts, interleukin-6, C-reactive protein) and hypothalamic-pituitary-adrenal systems (cortisol), and used as predictor variables in regression models. Compared with controls, individuals with insomnia had a shorter sleep duration ( P < 0.05), and a higher hypothalamic-pituitary-adrenal and inflammatory composite score ( P < 0.05). The higher inflammatory score was mainly due to higher circulating monocytes ( P < 0.05), rather than differences in interleukin-6 or C-reactive protein. In persistent insomnia disorder, cortisol is upregulated and associated with actigraphy- and diary-based wake after sleep onset, suggesting that wake after sleep onset may serve as a marker to identify individuals at increased risks for disorders associated with a hyperactive hypothalamic-pituitary-adrenal system. The absence of autonomic and pro-inflammatory changes (interleukin-6, C-reactive protein), despite a substantial decrease in actigraphic sleep duration, may relate to a higher resilience to the adverse biological consequences of insomnia in this young age group. [ABSTRACT FROM AUTHOR]

Humans display a trait-like response to sleep loss. However, it is not known whether this trait-like response can be captured by a mathematical model from only one sleep-loss condition to facilitate neurobehavioural performance prediction of the same individual during a different sleep-loss condition. In this paper, we investigated the extent to which the recently developed unified mathematical model of performance ( UMP) captured such trait-like features for different sleep-loss conditions. We used the UMP to develop two sets of individual-specific models for 15 healthy adults who underwent two different sleep-loss challenges (order counterbalanced; separated by 2-4 weeks): (i) 64 h of total sleep deprivation ( TSD) and (ii) chronic sleep restriction ( CSR) of 7 days of 3 h nightly time in bed. We then quantified the extent to which models developed using psychomotor vigilance task data under TSD predicted performance data under CSR, and vice versa. The results showed that the models customized to an individual under one sleep-loss condition accurately predicted performance of the same individual under the other condition, yielding, on average, up to 50% improvement over non-individualized, group-average model predictions. This finding supports the notion that the UMP captures an individual's trait-like response to different sleep-loss conditions. [ABSTRACT FROM AUTHOR]

The lack of timely access to diagnosis and treatment for sleep disorders is well described, but little attention has been paid to understanding how multiple system constraints contribute to long waiting times. The objectives of this study were to identify system constraints leading to long waiting times at a multidisciplinary sleep centre, and to use patient flow simulation modelling to test solutions that could improve access. Discrete-event simulation models of patient flow were constructed using historical data from 150 patients referred to the sleep centre, and used to both examine reasons for access delays and to test alternative system configurations that were predicted by administrators to reduce waiting times. Four possible solutions were modelled and compared with baseline, including addition of capacity to different areas at the sleep centre and elimination of prioritization by urgency. Within the model, adding physician capacity improved time from patient referral to initial physician appointment, but worsened time from polysomnography requisition to test completion, and had no effect on time from patient referral to treatment initiation. Adding respiratory therapist did not improve model performance compared with baseline. Eliminating triage prioritization worsened time to physician assessment and treatment initiation for urgent patients without improving waiting times overall. This study demonstrates that discrete-event simulation can identify multiple constraints in access-limited healthcare systems and allow suggested solutions to be tested before implementation. The model of this sleep centre predicted that investments in capacity expansion proposed by administrators would not reduce the time to a clinically meaningful patient outcome. [ABSTRACT FROM AUTHOR]

Dyslipidaemia and increased oxidative stress have been reported in severe obstructive sleep apnea, and both may be related to the development of cardiovascular disease. We have previously shown in a randomized crossover study in patients with moderate to severe obstructive sleep apnea that therapeutic continuous positive airway pressure treatment for 8 weeks improved postprandial triglycerides and total cholesterol when compared with sham continuous positive airway pressure. From this study we have now compared the effect of 8 weeks of therapeutic continuous positive airway pressure and sham continuous positive airway pressure on oxidative lipid damage and plasma lipophilic antioxidant levels. Unesterified cholesterol, esterified unsaturated fatty acids (cholesteryl linoleate: C18:2; and cholesteryl arachidonate: C20:4; the major unsaturated and oxidizable lipids in low-density lipoproteins), their corresponding oxidized products [cholesteryl ester-derived lipid hydroperoxides and hydroxides (CE-O(O)H)] and antioxidant vitamin E were assessed at 20:30 hours before sleep, and at 06:00 and 08:30 hours after sleep. Amongst the 29 patients completing the study, three had incomplete or missing [CE-O(O)H] data. The mean apnea -hypopnoea index, age and body mass index were 38 per hour, 49 years and 32 kg m−2, respectively. No differences in lipid-based oxidative markers or lipophilic antioxidant levels were observed between the continuous positive airway pressure and sham continuous positive airway pressure arms at any of the three time-points [unesterified cholesterol 0.01 m m, P > 0.05; cholesteryl linoleate: C18:2 0.05 m m, P > 0.05; cholesteryl arachidonate: C20:4 0.02 m m, P = 0.05; CE-O(O)H 2.5 n m, P > 0.05; and lipid-soluble antioxidant vitamin E 0.03 μ m, P > 0.05]. In this study, accumulating CE-O(O)H, a marker of lipid oxidation, does not appear to play a role in oxidative stress in obstructive sleep apnea. [ABSTRACT FROM AUTHOR]

Short sleep duration has been found recently to be a predictor of proteinuria. However, population-based investigations addressing the association between self-reported sleep duration and glomerular filtration rate ( GFR) among hypertensive patients are lacking. We therefore sought to investigate the extent to which self-reported sleep duration might be associated with reduced GFR in a large hypertensive population in rural northeast China. A total of 5555 hypertensive participants, aged ≥35 years, in rural areas of Liaoning Province, China, were screened between January 2012 and August 2013, using a stratified, cluster multi-stage sampling scheme. Anthropometric measurements, self-reported sleep duration, blood biochemical indexes and other health-related variables were collected by medically trained personnel. Reduced GFR was defined as the estimated GFR (e GFR) < 60 mL min−1 1.73 m2. On average, participants slept for 6.9 ± 1.6 h per night. Mean self-reported sleep duration decreased with e GFR ( P < 0.001). For both genders, a lower prevalence of reduced GFR was observed among participants who slept ≤6 h per night in total. In the multivariable regression model, after adjustments for age, gender, ethnicity, lifestyle factors, clinical correlates, depressive symptoms and general quality of life, participants who slept for 6 h or less per night were associated with a higher risk of reduced GFR [odds ratio ( OR: 1.70, 95% confidence interval ( CI): 1.05-2.73] compared with the reference group (self-reported sleep duration >7 and ≤8 h day−1). We concluded that short self-reported sleep duration (≤6 h per night) was related significantly to an increased risk of reduced GFR in a hypertensive population. This novel risk factor should be taken into consideration during daily management of hypertension to prevent chronic kidney disease. [ABSTRACT FROM AUTHOR]