Sleep Structure Research Articles

Pharmacotherapy of insomnia in patients with occupational chronic mercury intoxication

Introduction. Among occupational poisoning, chronic mercury intoxication (CMI) in the Irkutsk region occupies a leading position. Objective. To give a comparative analysis of the methods of pharmacotherapy of sleep disorders in patients in the long-term CRI. Material and methods. The study included 60 patients with long-term CRI, divided into two equal groups of 30 cases: in the first, the average age was 56.0 ± 0.7, in the second, the average age was 57.1 ± 3.0. Questionnaires were conducted using the hospital scale of anxiety and depression, electroencephalographic, polysomnographic studies before and after treatment. During the study, two treatment regimens for sleep disorders were implemented: the first regimen included the administration of an antidepressant (trazodone) and the chemical analog of melatonin (melaxen), and the second regimen was zolpidem. Statistical processing of the research results was carried out using the software package “Statistica 6.0”. Results. After treatment, in the first group there was an increase in the duration of the total sleep time (p = 0.0008), a decrease in the time of falling asleep (p = 0.004), a decrease in the total number of activations (p = 0.00005), and the time of wakefulness in bed (p = 0.0018), an increase in the representation of delta sleep (p = 0.03), and REM sleep (p = 0.004), an increase in the sleep efficiency index (p = 0.0008), and a decrease in the integrative sleep quality index (p = 0.001). In the second group, only a decrease in the latent period of stage 1 (time of falling asleep) was established (p = 0.05). Discussion. After treatment with trazodone in combination with melaxen, a decrease in the severity of presomnic and intrasomnic disorders was found, and in patients taking zolpidem, only the severity of presomnic disorders was reduced. The results confirm the hypothesized cause of dissominal disorders in CRI (changes in the activity of the limbic-reticular complex). Conclusion. The use of trazodone in combination with melaxen proves the improvement of the qualitative and quantitative indices of the structure of night sleep in patients in the long-term postexposure period of CRI.

Ramelteon modulates gamma oscillations in the rat primary motor cortex during non-REM sleep

Sleep disorders adversely affect daily activities and cause physiological and psychiatric problems. The shortcomings of benzodiazepine hypnotics have led to the development of ramelteon, a melatonin MT1 and MT2 agonist. Although the sleep-promoting effects of ramelteon have been documented, few studies have precisely investigated the structure of sleep and neural oscillatory activities. In this study, we recorded electrocorticograms in the primary motor cortex, the primary somatosensory cortex and the olfactory bulb as well as electromyograms in unrestrained rats treated with either ramelteon or vehicle. A neural-oscillation-based algorithm was used to classify the behavior of the rats into three vigilance states (e.g., awake, rapid eye movement (REM) sleep, and non-REM (NREM) sleep). Moreover, we investigated the region-, frequency- and state-specific modulation of extracellular oscillations in the ramelteon-treated rats. We demonstrated that in contrast to benzodiazepine treatment, ramelteon treatment promoted NREM sleep and enhanced fast gamma power in the primary motor cortex during NREM sleep, while REM sleep was unaffected. Gamma oscillations locally coordinate neuronal firing, and thus, ramelteon modulates neural oscillations in sleep states in a unique manner and may contribute to off-line information processing during sleep.

Budgerigars have complex sleep structure similar to that of mammals.

Birds and mammals share specialized forms of sleep including slow wave sleep (SWS) and rapid eye movement sleep (REM), raising the question of why and how specialized sleep evolved. Extensive prior studies concluded that avian sleep lacked many features characteristic of mammalian sleep, and therefore that specialized sleep must have evolved independently in birds and mammals. This has been challenged by evidence of more complex sleep in multiple songbird species. To extend this analysis beyond songbirds, we examined a species of parrot, the sister taxon to songbirds. We implanted adult budgerigars (Melopsittacus undulatus) with electroencephalogram (EEG) and electrooculogram (EOG) electrodes to evaluate sleep architecture, and video monitored birds during sleep. Sleep was scored with manual and automated techniques, including automated detection of slow waves and eye movements. This can help define a new standard for how to score sleep in birds. Budgerigars exhibited consolidated sleep, a pattern also observed in songbirds, and many mammalian species, including humans. We found that REM constituted 26.5% of total sleep, comparable to humans and an order of magnitude greater than previously reported. Although we observed no spindles, we found a clear state of intermediate sleep (IS) similar to non-REM (NREM) stage 2. Across the night, SWS decreased and REM increased, as observed in mammals and songbirds. Slow wave activity (SWA) fluctuated with a 29-min ultradian rhythm, indicating a tendency to move systematically through sleep states as observed in other species with consolidated sleep. These results are at variance with numerous older sleep studies, including for budgerigars. Here, we demonstrated that lighting conditions used in the prior budgerigar study-and commonly used in older bird studies-dramatically disrupted budgerigar sleep structure, explaining the prior results. Thus, it is likely that more complex sleep has been overlooked in a broad range of bird species. The similarities in sleep architecture observed in mammals, songbirds, and now budgerigars, alongside recent work in reptiles and basal birds, provide support for the hypothesis that a common amniote ancestor possessed the precursors that gave rise to REM and SWS at one or more loci in the parallel evolution of sleep in higher vertebrates. We discuss this hypothesis in terms of the common plan of forebrain organization shared by reptiles, birds, and mammals.

An algorithm for actigraphy-based sleep/wake scoring: Comparison with polysomnography

ObjectiveTo evaluate the accuracy of actigraphy against polysomnography (PSG) as gold standard using a newly developed algorithm for sleep/wake discrimination that explicitly models the temporal structure of sleep. MethodsPSG was recorded in 11 men and 9 women (age 71.1±5.0) to evaluate suspected neuropsychiatric sleep disturbances. Simultaneously, wrist actigraphy was recorded, from which 37 features were computed for each 1-min epoch. We compared prediction of PSG-derived sleep/wake states for each of these features between our newly developed algorithm, and four state-of-the-art algorithms. The algorithms were evaluated using a leave-one-subject out cross validation. ResultsThe new algorithm classified 84.9% of sleep epochs (sensitivity) and 74.2% of wake epochs correctly (specificity), leading to a sleep/wake scoring accuracy of 79.0%. Four out of five sleep parameters were estimated more accurately by the new algorithm than by state-of-the-art algorithms. ConclusionThe proposed algorithm achieved a significantly higher specificity than state-of-the-art algorithm, with only minor decrease in sensitivity for patients with sleep disorders. We assume this reflects the capability of the algorithm to explicitly model sleep architecture. SignificanceThe unobtrusive assessment of sleep/wake cycles is particularly relevant for patients with neuropsychiatric diseases that are associated with sleep disturbances, such as depression or dementia.

Characteristics of Sleep Structure Assessed by Objective Measurements in Patients With Amnestic Mild Cognitive Impairment: A Meta-Analysis

Objectives: This study aims to explore the differences of sleep structure between patients with amnestic mild cognitive impairment (aMCI) and elderly people with normal cognition, which will help to provide evidence for the relationship between sleep disturbances and cognitive impairment.Methods: A systematic review and meta-analysis were conducted on the literature on sleep parameters obtained by polysomnography or actigraphy in patients with aMCI. The PubMed and EMBASE databases were searched up to April 2020. Inclusion and exclusion criteria were established according to evidence-based medicine methods, and data of all eligible studies were meta-analyzed using the Review Manager 5.3 software.Results: Among the 1,171 literature articles on sleep structure of patients with MCI, eight case-control studies met the inclusion criteria and were included in this meta-analysis. A total of 278 subjects were included, of which 103 were patients with aMCI and 175 were elderly people with normal cognition. The results showed that sleep efficiency (SE) and slow wave sleep (SWS) of patients with aMCI were significantly lower than those of healthy elderly people. Compared with the control group, the percentage of stage 1 of non-rapid eye movement (N1%) in the aMCI patients group increased, and the percentage of stage 2 of non-rapid eye movement (N2%) decreased.Conclusions: Patients with aMCI may experience more severe sleep disturbances than normal cognitive elderly people. There were specific changes, especially in SE and SWS, in the sleep structure of patients with aMCI when compared to those with normal cognition.

Insomnia is frequent in amyotrophic lateral sclerosis at the time of diagnosis

Sleep-disordered breathing and sleep-related symptoms are frequent in patients with severe amyotrophic lateral sclerosis (ALS). We aimed to describe sleep quality, sleep structure, and the occurrence of sleep-disordered breathing in patients with early ALS, at the time of initial evaluation in a tertiary care center. Sleep-related symptoms were collected using questionnaires, the Pittsburgh Sleep quality Index (PSQI), and the Epworth Sleepiness Scale. Sleep was studied by inpatient overnight polysomnography. Fourteen men and 13 women (age 66 ± 12 years, ALSFRS-R 39 ± 6) were included, among which 12 patients had disease with bulbar onset. Eighteen (69%) patients complained of insomnia, fifteen of which (55%) reported poor sleep quality (PSQI > 5). No patient had an Epworth Sleepiness Scale > 10. Respiratory and polysomnography characteristics were similar between patients with poor or good sleep quality. Sleep efficiency and REM sleep duration were normal relative to normative values, while wake after sleep onset was increased. Fifteen patients had obstructive sleep apnea syndrome (8 mild, 3 moderate, and 4 severe). No patient had central apnea syndrome. Insomnia was highly prevalent in patients with early ALS, independent of respiratory impairment. Poor sleep quality was strongly associated with insomnia.

Differentiating Oneiric Stupor in Agrypnia Excitata From Dreaming Disorders

Oneiric Stupor (OS) in Agrypnia Excitata represents a peculiar condition characterized by the recurrence of stereotyped gestures such as mimicking daily-life activities associated with the reporting of a dream mentation consisting in a single oneiric scene. It arises in the context of a completely disorganized sleep structure lacking any physiological cyclic organization, thus, going beyond the concept of abnormal dream. However, a proper differential diagnosis of OS, in the complex world of the “disorders of dreaming” can become quite challenging. The aim of this review is to provide useful clinical and videopolygraphic data on OS to differentiate it from other dreaming disorders. Each entity will be clinically evaluated among the areas of dream mentation and abnormal sleep behaviors and its polygraphic features will be analyzed and distinguished from OS.

Jak infekcje i cytokiny wpływają na sen i zachowanie człowieka i zwierząt?

Produkowane podczas reakcji zapalnej cytokiny pro-zapalne (IL-1b, IL-6, TNFa) i prostagandyny (np. PGE2) regulują aktywność leukocytów i pobudzają produkcję białek ostrej fazy np. CRP. Oddziałują także na na różne struktury mózgu i wywołują szereg zmian behawioralnych łącznie opisywanych jako zachowania chorobowe (ang. sickness behavior). Składa się ma nie między innymi gorączka, zaburzenia łaknienia, aktywności lokomotorycznej i poznawczej oraz zaburzenia struktury i długości snu. Najczęściej ich działanie powoduje skrócenie fazy zasypiania i fazy snu paradoksalnego (REM) oraz wydłużenie fazy snu wolnofalowego (SWS). Podobne działanie mają także IL-2 i cytokiny należące do rodziny interferonów, w tym najważniejsze dla odpowiedzi przeciwirusowej ? interferony typu I (IFN I). Kierunek i nasilenie tych zmian zależą od fazy i nasilenia infekcji.
 Indukowane przez cytokiny pro-zapalne zmiany behawioralne są wysoce adaptacyjne i konserwatywne ewolucyjnie.

Clinical characteristics of Asian patients withsleep apnea with low arousal threshold and sleep structure change with continuous positive airway pressure.

Low respiratory arousal threshold (ArTH) has been observed to be prevalent in patients withobstructive sleep apnea (OSA), and is associated with poor adherence to continuous positive airway pressure (CPAP) treatment. This study aimed to examine the associations between low ArTH and clinical characteristics. The second aim was to examine sleep structure changes between diagnostic polysomnography (PSG) and CPAP titration studies. PSG data for 3718 adults who had an apnea-hypopnea index (AHI) ≥ 5 were reviewed retrospectively, as well as 206 CPAP titration studies among these participants. Participants were dichotomized into low- and high-ArTH groups according to their PSG parameters. The associations between low ArTH and clinical characteristics were examined by multivariate logistic regressions. The sleep structure changes between PSG and CPAP titration studies were examined by repeated measures ANOVA. Fifty percent of patients withOSA had low ArTH. Compared with high-ArTH patients, low-ArTH patients were less obese and composed of a higher percentage of women. In logistic regression models, low ArTH was associated with bruxism and nocturia, but not with illnesses after adjusting for AHI and body mass index. Compared with diagnostic PSG studies, low-ArTH patients had significantly decreased stage changes and increased percentage of rapid eye movement sleep during CPAP titration studies. Low ArTH was prevalent in this large sample of patients withOSA. Arousal threshold was not associated with an increased risk of physical illnesses but was with certain clinical complaints. Low-ArTH patients benefited from CPAP titration study for improved sleep structure.

Inhibiting Epileptiform Activity in Cognitive Disorders: Possibilities for a Novel Therapeutic Approach.

Cognitive impairment is a common and seriously debilitating symptom of various mental and neurological disorders including autism, attention deficit hyperactivity disorder, multiple sclerosis, epilepsy, and neurodegenerative diseases, like Alzheimer’s disease. In these conditions, high prevalence of epileptiform activity emerges as a common pathophysiological hallmark. Growing body of evidence suggests that this discrete but abnormal activity might have a long-term negative impact on cognitive performance due to neuronal circuitries’ remodeling, altered sleep structure, pathological hippocampo–cortical coupling, and even progressive neuronal loss. In animal models, epileptiform activity was shown to enhance the formation of pathological amyloid and tau proteins that in turn trigger network hyperexcitability. Abolishing epileptiform discharges might slow down the cognitive deterioration. These findings might provide basis for therapeutic use of antiepileptic drugs in neurodegenerative cognitive disorders. The aim of our review is to describe the data on the prevalence of epileptiform activity in various cognitive disorders, to summarize the current knowledge of the mechanisms of epileptic activity in relation to cognitive impairment, and to explore the utility of antiepileptic drugs in the therapy of cognitive disorders. We also propose future directions for drug development and novel therapeutic interventions targeting epileptiform discharges in these disorders.

Sleep changes and epileptiform discharges in Parkinson's and Alzheimer's disease: 24-hour EEG study

Objective: Sleep changes are common but the occurrence of epilepsy is not known in Parkinson's disease (PD), while increasing amount of data suggests that Alzheimer's disease (AD) may be associated with higher risk of epileptic seizures. We aimed to investigate the sleep structure, cognitive dysfunction, prevalence of epileptiform discharges and their relationship in PD and AD patients.

Sleep problems in Rett syndrome animal models: A systematic review.

Due to the discovery of Rett Syndrome (RTT) genetic mutations, animal models have been developed. Sleep research in RTT animal models may unravel novel neural mechanisms for this severe neurodevelopmental heritable rare disease. In this systematic literature review we summarize the findings on sleep research of 13 studies in animal models of RTT. We found disturbed efficacy and continuity of sleep in all genetically mutated models of mice, cynomolgus monkeys, and Drosophila. Models presented highly fragmented sleep with distinct differences in 24-hr sleep/wake cyclicity and circadian arrhythmicity. Overall, animal models mimic sleep complaints reported in individuals with RTT. However, contrary to human studies, in mutant mice, attenuated sleep delta waves, and sleep apneas in non-rapid eye movement sleep were reported. Future studies may focus on sleep structure and EEG alterations, potential central mechanisms involved in sleep fragmentation and the occurrence of sleep apnea across different sleep stages. Given that locomotor dysfunction is characteristic of individuals with RTT, studies may consider to integrate its potential impact on the behavioral analysis of sleep.

Association between sleep structure and amnesic mild cognitive impairment in patients with insomnia disorder: a case-control study.

To examine the association between sleep structure and amnesic mild cognitive impairment (aMCI) in patients with insomnia disorder. A total of 256 patients with insomnia disorder were diagnosed by neurologists, 45 of whom were diagnosed with aMCI according to the Petersen criteria, and 45 participants with intact cognition were chosen as controls matched for age and education. A case-control study was conducted to compare sleep structure between aMCI and control patients with insomnia disorder. We evaluated self-reported sleep problems by the Insomnia Severity Index and objective sleep features by polysomnography. Logistic regression models were used to estimate the associations between sleep parameters and aMCI in patients with insomnia disorder. There was no significant difference in Insomnia Severity Index scores between the aMCI and control groups. In the logistic regression after adjustment for covariates, people with a longer sleep duration (adjusted odds ratio [aOR] = 0.56, 95% confidence interval [CI]: 0.36-0.89), greater sleep efficiency (aOR = 0.50, 95% CI: 0.32-0.77), and a higher percentage of total sleep time in stage 3 of non-rapid eye movement sleep (N3%) (aOR = 0.02, 95% CI: 0.01-0.15) have a lower relative probability of having aMCI. By contrast, higher N1% (aOR = 2.28, 95% CI: 1.36-3.82) and wake after sleep onset (aOR = 1.31, 95% CI: 1.11-1.55) may be risk factors for aMCI in patients with insomnia. In patients with insomnia disorder, sleep duration, sleep fragmentation, sleep efficiency, N1% and N3% were independently associated with the presence of aMCI. In the clinical setting, if patients with insomnia show much more serious abnormalities in these sleep indices, clinicians should pay attention to their cognitive function. In-depth research would also be worthwhile to elaborate the causality between sleep and cognitive decline.

Sleep Disturbances in Patients with Asperger Syndrome Related to the Severity of their Symptoms

Patients with Asperger syndrome (AS) usually report sleep problems. The objective of this study was to compare the general sleep structure of children with Asperger syndrome to that displayed by healthy children through polysomnographic study. Sleep characteristics were compared to severity of AS symptoms. Two groups of children aged 8–12 years were studied, one group with AS patients and the other with healthy children. Results show that patients with AS had a significant increase in sleep latency, REM latency and a decrease in the number of REM sleep episodes. It was also observed that the AS patients exhibit a correlation between the fragmentation of sleep and the increase in the intensity of the AS symptoms. It is concluded that sleep latency, REM latency and number of episodes are affected in AS patients and the AS symptoms are related to sleep disturbances in patients.

Sleep Disturbance Forecasts β-Amyloid Accumulation across Subsequent Years

Experimental sleep-wake disruption in rodents and humans causally modulates β-amyloid (Aβ) dynamics (e.g., [1-3]). This leads to the hypothesis that, beyond cross-sectional associations, impaired sleep structure and physiology could represent prospective biomarkers of the speed with which Aβ accumulates over time. Here, we test the hypothesis that initial baseline measures of non-rapid eye movement (NREM) sleep slow-wave activity (SWA) and sleep quality (efficiency) provide future forecasting sensitivity to the rate of Aβ accumulation over subsequent years. A cohort of clinically normal older adults was assessed using objective sleep polysomnography in combination with longitudinal tracking of Aβ accumulation with [11C]PiB positron emission tomography (PET) imaging. Both the proportion of NREM SWA below 1Hz and the measure of sleep efficiency predicted the speed (slope) of subsequent Aβ deposition over time, and these associations remained robust when taking into account additional cofactors of interest (e.g., age, sex, sleep apnea). Moreover, these measures were specific, such that no other macro- and microphysiological architecture metrics of sleep demonstrated such sensitivity. Our data support the proposal that objective sleep markers could be part of a set of biomarkers that statistically forecast the longitudinal trajectory of cortical Aβ deposition in the human brain. Sleep may therefore represent a potentially affordable, scalable, repeatable, and non-invasive tool for quantifying of Aβ pathological progression, prior to cognitive symptoms of Alzheimer's disease (AD).

Sleep Quality, Sleep Structure, and PER3 Genotype Mediate Chronotype Effects on Depressive Symptoms in Young Adults.

Depression and its related mood disorders are a major global health issue that disproportionately affects young adults. A number of factors that influence depressive symptoms are particularly relevant to the young adult developmental stage, including sleep loss, poor sleep quality, and the tendency toward eveningness in circadian preferences. However, relatively few studies have examined the relationship between sleep and circadian phenotypes, and their respective influences on mood, or considered potential molecular mechanisms driving these associations. Here, we use a multi-year, cross-sectional study of 806 primarily undergraduates to examine the relationships between sleep-wake chronotype, sleep disturbance, depression and genotypes associated with the PER3 variable number of tandom repeats (VNTR) polymorphism—circadian gene variants associated with both chronotype and sleep homeostatic drive. In addition, we use objective, Fitbit-generated sleep structure data on a subset of these participants (n = 67) to examine the relationships between chronotype, depression scores, actual measures of sleep duration, social jetlag, and the percent of deep and rapid eye movement (REM) sleep per night. In this population, chronotype is weakly associated with depressive symptoms and moderately correlated with self-reported sleep disturbance. Sleep disturbance is significantly associated with depression scores, but objective sleep parameters are not directly correlated with Beck Depression Inventory (BDI-II) scores, with the exceptions of a moderate correlation between social jetlag and depression scores in females and a marginal correlation between sleep duration and depression scores. Multiple regression and path analyses reveal that chronotype effects on depressive symptoms in this population are mediated largely by sleep disturbance. The PER3 VNTR genotype significantly predicts depressive symptoms in a model with objective sleep parameters, but it does not significantly predict depressive symptoms in a model with chronotype or subjective sleep disturbance. Interestingly, PER35,5 genotypes, in males only, are independently related to chronotype and depression scores. Our results support hypotheses linking subjective sleep quality and chronotype and provide a first step in understanding how objective sleep structure may be linked to chronotype and depressive symptoms. Our results also suggest that circadian gene variants may show sex-specific effects linking sleep duration and sleep structure to depression.

Juvenile hormone affects the development and strength of circadian rhythms in young bumble bee (Bombus terrestris) workers

The circadian and endocrine systems influence many physiological processes in animals, but little is known on the ways they interact in insects. We tested the hypothesis that juvenile hormone (JH) influences circadian rhythms in the social bumble bee Bombus terrestris. JH is the major gonadotropin in this species coordinating processes such as vitellogenesis, oogenesis, wax production, and behaviors associated with reproduction. It is unknown however, whether it also influences circadian processes. We topically treated newly-emerged bees with the allatoxin Precocene-I (P-I) to reduce circulating JH titers and applied the natural JH (JH-III) for replacement therapy. We repeated this experiment in three trials, each with bees from different source colonies. Measurements of ovarian activity suggest that our JH manipulations were effective; bees treated with P-I had inactive ovaries, and this effect was fully recovered by subsequent JH treatment. We found that JH augments the strength of circadian rhythms and the pace of rhythm development in individually isolated newly emerged worker bees. JH manipulation did not affect the free-running circadian period, overall level of locomotor activity, sleep amount, or sleep structure. Given that acute manipulation at an early age produced relatively long-lasting effects, we propose that JH effects on circadian rhythms are mostly organizational, accelerating the development or integration of the circadian system.

Cyclic alternating pattern estimation based on a probabilistic model over an EEG signal

A probabilistic model for sleep analysis is proposed in this work, modeling the temporal relation between the sleep structure and the presence of the electroencephalogram (EEG) Cyclic Alternating Pattern (CAP) with a Hidden Markov Model (HMM). Sleep scoring is frequently performed by assigning a state to each thirty second epoch. However, this approach does not provide enough time resolution to efficiently detect the CAP since, by definition, the CAP cycles are assessed by applying the scoring rules to one second epochs of the EEG signal. Thus, a clustering analysis was employed, with a one second epoch, over the EEG signal to create clusters that were then encoded using symbolic dynamics to produce words. Two algorithms for clustering were analyzed, specifically the self-organizing map and the Gaussian Mixture Model (GMM). The words were then fed to the HMM to determine the presence of the CAP. Both single-channel and multi-channel (based on sensor fusion) approaches were tested. The best results were attained using the GMM with three Gaussians, achieving an average accuracy, sensitivity, specificity and area under the receiver operating characteristic curve of, respectively, 72%, 66%, 75% and 0.71 for single-channel and 76%, 61%, 85% and 0.73 for multi-channel. This results are in the specialist agreement range with visual analysis. Therefore, the proposed model is capable of providing a new view over the CAP cycles by simplifying the complex EEG signal to a simple sequence of symbols. Such analysis can be significantly challenging to perform in more abstract models.

The effect of nocturnal “meat” versus “vegetarian” dinners on sleep quality and daily functioning

Sleep and nutrition are central to an organism's continued physiological existence. Moreover, both of these functions include significant social-behavioral, educational, and cultural elements. This study examined the effects of two types of nocturnal dinners ("vegetarian" versus "meat") on the quality and quantity of sleep, as well as on subjective sleepiness and attention levels the following morning. 20 healthy subjects (10 men and 10 women) participated in a lab polysomnography study for two non-consecutive nights at the Sleep Institute at Tel-Hai College. They completed questionnaires (Karolinska Sleepiness Scale (KSS) and Brief Symptom Inventory Questionnaire (BSI)), as well as a computerized attention and concentration test (Conner's Continuous Performance Test-III (CPT-III)), on the mornings after each night of polysomnography. On the first night, subjects consumed a vegetarian meal made up of non-animal ingredients (vegetables and vegetable proteins). On the second night, they were given a meat meal composed of carbohydrates, fats, and animal proteins. No significant differences were measured in the various sleep parameters: efficacy, structure, and quality of sleep. There were also no significant differences found in the behavioral measures examined: subjective sleepiness (KSS), mood (BSI), and attention and concentration abilities (CPT-III). The findings of this study indicate that, contrary to popular belief, consuming a meat dinner may not affect a person's quality of sleep, or their ability to function the morning after, differently than a vegetarian dinner. Future studies should further examine the relationship between sleep and nutrition. The clinical trial is registered under the number 0010-18ASMC.

Non-contact home-adapted device estimates sleep stages in middle-aged men: A preliminary study.

Sleep monitoring is essential to maintain a healthy life, especially for the elderly who want to age well. Among various forms of sleep devices, the non-wearable and home-adapted device might be preferred because it can be easily used. In this study, we evaluated the performance of a non-contact home-adapted device compared to polysomnography (PSG), a gold standard method. As a preliminary study, eight subjects were recorded over fourteen nights through PSG. The non-contact home-adapted device comprised a microwave sensor, passive infrared sensor, and smartphone application. Through the device, heart rate, respiratory rate, and body movement were collected and used to estimate sleep stages. Sleep structure was labeled in four classes: wake, REM, light, and deep sleep, and were classified using a weighted k-nearest neighbor algorithm. The device correctly estimated sleep structures with an overall epoch-by-epoch accuracy of 98.65% ± 0.05% based on leave-one-out cross-validation. The device showed significantly positive correlations with PSG in sleep indices including total sleep time, sleep efficiency, and wake after sleep onset. Our findings demonstrate a good performance of this non-contact and home-adapted device and suggest its suitability for sleep monitoring.