Circadian Rhythm Sleep Disorder: Irregular Sleep Wake Rhythm Type

Circadian oscillation in primary cilium length by clock genes regulates fibroblast cell migration

Various mammalian cells have autonomous cellular clocks that are produced by the transcriptional cycle of clock genes. Cellular clocks provide circadian rhythms for cellular functions via transcriptional and cytoskeletal regulation. The vast majority of mammalian cells possess a primary cilium, an organelle protruding from the cell surface. Here, we investigated the little-known relationship between circadian rhythm and primary cilia. The length and number of primary cilia showed circadian dynamics both in vitro and in vivo. The circadian rhythm of primary cilium length was abolished by SR9011 and Bmal1 knockout. A centrosomal protein, pericentrin, transiently accumulates in centriolar satellites, the base of primary cilia at the shortest cilia phase, and induces elongation of primary cilia at the longest cilia phase in the circadian rhythm of primary cilia. In addition, rhythmic cell migration during wound healing depends on the length of primary cilia and affects the rate of wound healing. Our findings demonstrate that the circadian dynamics of primary cilium length by clock genes control fibroblast migration and could provide new insights into chronobiology.

Sleep regularity and mortality: a prospective analysis in the UK Biobank

Background

Irregular sleep-wake timing may cause circadian disruption leading to several chronic age-related diseases. We examined the relationship between sleep regularity and risk of all-cause, cardiovascular disease (CVD), and cancer mortality in 88,975 participants from the prospective UK Biobank cohort.

Methods

The sleep regularity index (SRI) was calculated as the probability of an individual being in the same state (asleep or awake) at any two time points 24 hr apart, averaged over 7 days of accelerometry (range 0-100, with 100 being perfectly regular). The SRI was related to the risk of mortality in time-to-event models.

Results

The mean sample age was 62 years (standard deviation [SD], 8), 56% were women, and the median SRI was 60 (SD, 10). There were 3010 deaths during a mean follow-up of 7.1 years. Following adjustments for demographic and clinical variables, we identified a non-linear relationship between the SRI and all-cause mortality hazard (p [global test of spline term]<0.001). Hazard ratios, relative to the median SRI, were 1.53 (95% confidence interval [CI]: 1.41, 1.66) for participants with SRI at the 5th percentile (SRI = 41) and 0.90 (95% CI: 0.81, 1.00) for those with SRI at the 95th percentile (SRI = 75), respectively. Findings for CVD mortality and cancer mortality followed a similar pattern.

Conclusions

Irregular sleep-wake patterns are associated with higher mortality risk.

Funding

National Health and Medical Research Council of Australia (GTN2009264; GTN1158384), National Institute on Aging (AG062531), Alzheimer's Association (2018-AARG-591358), and the Banting Fellowship Program (#454104).

Images: Irregular sleep-wake rhythm disorder in transgender individuals

Growing evidence suggests that transgender individuals face a significant health disparity and are particularly vulnerable to sleep disorders. We present two patients who developed irregular sleep-wake rhythm disorder after gender reassignment and hormone replacement therapy. The growing interest in transgender health warrants further evaluation of the effects and frequency of all sleep disorders in this population. Efforts to address sleep disorders should consider assessing sleep disturbance in terms of sleep/wake patterns and schedules.

CITATION

Kokash A, Vendrame M. Images: irregular sleep-wake rhythm disorder in transgender individuals. J Clin Sleep Med. 2023;19(11):1981-1984.

Sleep Regularity and Mortality: A Prospective Analysis in the UK Biobank

Background

Irregular sleep-wake timing may cause circadian disruption leading to several chronic age-related diseases. We examined the relationship between sleep regularity and risk of all-cause, cardiovascular disease (CVD), and cancer mortality in 88,975 participants from the prospective UK Biobank cohort.

Methods

The sleep regularity index (SRI) was calculated as the probability of an individual being in the same state (asleep or awake) at any two time points 24 hours apart, averaged over 7-days of accelerometry (range 0-100, with 100 being perfectly regular). The SRI was related to the risk of mortality in time-to-event models.

Findings

The mean sample age was 62 years (SD, 8), 56% were women, and the median SRI was 60 (SD, 10). There were 3010 deaths during a mean follow-up of 7.1 years. Following adjustments for demographic and clinical variables, we identified a non-linear relationship between the SRI and all-cause mortality hazard (p [global test of spline term] < 0·001). Hazard Ratios, relative to the median SRI, were 1·53 (95% confidence interval [CI]: 1·41, 1·66) for participants with SRI at the 5th percentile (SRI = 41) and 0·90 (95% CI: 0·81, 1·00) for those with SRI at the 95th percentile (SRI = 75), respectively. Findings for CVD mortality and cancer mortality followed a similar pattern.

Conclusions

Irregular sleep-wake patterns are associated with higher mortality risk.

Funding

National Health and Medical Research Council of Australia (GTN2009264; GTN1158384), National Institute on Aging (AG062531), Alzheimer's Association (2018-AARG-591358), and the Banting Fellowship Program (#454104).

Tailored Music Listening in Persons With Dementia: A Feasibility Randomized Clinical Trial

Introduction: This study examined the feasibility, acceptability, and preliminary efficacy of tailored music listening intervention on sleep disturbances in older adults with dementia and their caregivers. Methods: We randomly assigned 33 older adults with dementia (mean age 71.7 [SD: 7.1], 72.7% female, 81.8% African American/Black) and their caregivers (mean age 58.4 [SD: 16.7], 72.7% female, 84.8% African American/Black) to a wait-list control or intervention group (NCT04157244). Results: The music intervention was feasible as evidenced by high study measure completion and retention rates (>90%). Recruitment was stopped prematurely due to the COVID-19 pandemic. We found mixed acceptability results from the survey and qualitative interviews with the participants. Both groups improved on objective sleep outcomes of sleep latency and wake sleep after onset. We found a small effect size for sleep duration post-intervention. Discussion: The findings provide preliminary evidence for the feasibility of a tailored music intervention and identified ways to improve its acceptability.

A review of automated sleep disorder detection

Automated sleep disorder detection is challenging because physiological symptoms can vary widely. These variations make it difficult to create effective sleep disorder detection models which support hu-man experts during diagnosis and treatment monitoring. From 2010 to 2021, authors of 95 scientific papers have taken up the challenge of automating sleep disorder detection. This paper provides an expert review of this work. We investigated whether digital technology and Artificial Intelligence (AI) can provide automated diagnosis support for sleep disorders. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines during the content discovery phase. We compared the performance of proposed sleep disorder detection methods, involving differ-ent datasets or signals. During the review, we found eight sleep disorders, of which sleep apnea and insomnia were the most studied. These disorders can be diagnosed using several kinds of biomedical signals, such as Electrocardiogram (ECG), Polysomnography (PSG), Electroencephalogram (EEG), Electromyogram (EMG), and snore sound. Subsequently, we established areas of commonality and distinctiveness. Common to all reviewed papers was that AI models were trained and tested with labelled physiological signals. Looking deeper, we discovered that 24 distinct algorithms were used for the detection task. The nature of these algorithms evolved, before 2017 only traditional Machine Learning (ML) was used. From 2018 onward, both ML and Deep Learning (DL) methods were used for sleep disorder detection. The strong emergence of DL algorithms has considerable implications for future detection systems because these algorithms demand significantly more data for training and testing when compared with ML. Based on our review results, we suggest that both type and amount of labelled data is crucial for the design of future sleep disorder detection systems because this will steer the choice of AI algorithm which establishes the desired decision support. As a guiding principle, more labelled data will help to represent the variations in symptoms. DL algorithms can extract information from these larger data quantities more effectively, therefore; we predict that the role of these algorithms will continue to expand.

Circadian Rhythm Sleep-Wake Disorders in Older Adults

The timing, duration, and consolidation of sleep result from the interaction of the circadian timing system with a sleep-wake homeostatic process. When aligned and functioning optimally, this allows for wakefulness throughout the day and a long consolidated sleep episode at night. Changes to either the sleep regulatory process or how they interact can result in an inability to fall asleep at the desired time, difficulty remaining asleep, waking too early, and/or difficulty remaining awake throughout the day. This mismatch between the desired timing of sleep and the ability to fall asleep and remain asleep is a hallmark of a class of sleep disorders called the circadian rhythm sleep-wake disorders. In this updated article, we discuss typical changes in the circadian regulation of sleep with aging; how age influences the prevalence, diagnosis, and treatment of circadian rhythm sleep disorders; and how neurologic diseases in older patient impact circadian rhythms and sleep.

Treatment of Circadian Rhythm Sleep-Wake Disorders

Circadian rhythm sleep-wake disorders (CRSWDs) are a distinct class of sleep disorders caused by alterations to the circadian time-keeping system, its entrainment mechanisms, or a mismatch between the endogenous circadian rhythm and the external environment. The main clinical manifestations are insomnia and excessive daytime sleepiness that often lead to clinically meaningful distress or cause mental, physical, social, occupational, educational, or other functional impairment. CRSWDs are easily mistaken for insomnia or early waking up, resulting in inappropriate treatment. CRSWDs can be roughly divided into two categories, namely, intrinsic CRSWDs, in which sleep disturbances are caused by alterations to the endogenous circadian rhythm system due to chronic changes in the regulation or capture mechanism of the biological clock, and extrinsic circadian rhythm sleep-wake disorders, in which sleep disorders, such as jet lag or shift-work disorder, result from environmental changes that cause a mismatch between sleep-wakefulness times and internal circadian rhythms. Sleep diaries, actigraphy, and determination of day and night phase markers (dim light melatonin onset and core body temperature minimum) have all become routine diagnostic methods for CRSWDs. Common treatments for CRSWD currently include sleep health education, time therapy, light therapy, melatonin, and hypnotic drug therapy. Here, we review the progress in the epidemiology, etiology, diagnostic evaluation, diagnostic criteria, and treatment of intrinsic CRSWD, with emphasis on the latter, in the hope of bolstering the clinical diagnosis and treatment of CRSWDs.

It's About Time: The Circadian Network as Time-Keeper for Cognitive Functioning, Locomotor Activity and Mental Health

A variety of organisms including mammals have evolved a 24h, self-sustained timekeeping machinery known as the circadian clock (biological clock), which enables to anticipate, respond, and adapt to environmental influences such as the daily light and dark cycles. Proper functioning of the clock plays a pivotal role in the temporal regulation of a wide range of cellular, physiological, and behavioural processes. The disruption of circadian rhythms was found to be associated with the onset and progression of several pathologies including sleep and mental disorders, cancer, and neurodegeneration. Thus, the role of the circadian clock in health and disease, and its clinical applications, have gained increasing attention, but the exact mechanisms underlying temporal regulation require further work and the integration of evidence from different research fields. In this review, we address the current knowledge regarding the functioning of molecular circuits as generators of circadian rhythms and the essential role of circadian synchrony in a healthy organism. In particular, we discuss the role of circadian regulation in the context of behaviour and cognitive functioning, delineating how the loss of this tight interplay is linked to pathological development with a focus on mental disorders and neurodegeneration. We further describe emerging new aspects on the link between the circadian clock and physical exercise-induced cognitive functioning, and its current usage as circadian activator with a positive impact in delaying the progression of certain pathologies including neurodegeneration and brain-related disorders. Finally, we discuss recent epidemiological evidence pointing to an important role of the circadian clock in mental health.

Human circadian variations

Circadian rhythms, present in most phyla across life, are biological oscillations occurring on a daily cycle. Since the discovery of their molecular foundations in model organisms, many inputs that modify this tightly controlled system in humans have been identified. Polygenic variations and environmental factors influence each person's circadian rhythm, contributing to the trait known as chronotype, which manifests as the degree of morning or evening preference in an individual. Despite normal variation in chronotype, much of society operates on a "one size fits all" schedule that can be difficult to adjust to, especially for certain individuals whose endogenous circadian phase is extremely advanced or delayed. This is a public health concern, as phase misalignment in humans is associated with a number of adverse health outcomes. Additionally, modern technology (such as electric lights and computer, tablet, and phone screens that emit blue light) and lifestyles (such as shift or irregular work schedules) are disrupting circadian consistency in an increasing number of people. Though medical and lifestyle interventions can alleviate some of these issues, growing research on endogenous circadian variability and sensitivity suggests that broader social changes may be necessary to minimize the impact of circadian misalignment on health.

Sunlight exposure and eye disorders in an economically active population: data from the KNHANES 2008-2012

BACKGROUND

Sunlight exposure is a major risk factor for eye disorders. Most outdoor workers cannot avoid sunlight exposure. This study aimed to analyze the relationship between outdoor sunlight exposure and eye disorders in an economically active population.

METHODS

This study analyzed the 2008-2012 Korea National Health and Nutritional Examination Survey data. Sunlight exposure was categorized as < 5 hours and > 5 hours. We also analyzed the dose-dependent relationship between exposure to sunlight and eye disorders (cataracts, pterygium, and age-related macular degeneration [AMD]) using data from 2010 to 2012 by subdividing the exposure groups into < 2 hours, 2-5 hours, and ≥ 5 hours. Eye disorders were diagnosed by an ophthalmologist. The study participants were stratified by sex, and the results were analyzed using the χ2 test and multiple logistic regression analysis.

RESULTS

In the female group, the odds ratio of pterygium in the high-level sunlight exposure group was 1.47 (95% confidence interval [CI]: 1.15-1.89). Regarding AMD, the odds ratios were 1.42 (95% CI: 1.16-1.73), 1.33 (95% CI: 1.03-1.73), and 1.58 (95% CI: 1.15-2.16) in the total, male, and female groups, respectively. Analysis of the dose-response relationship revealed that the odds ratios of pterygium in the high-level sunlight exposure subgroups of the total and female groups were 1.62 (95% CI: 1.25-2.08) and 2.00 (95% CI: 1.39-2.88), respectively.

CONCLUSIONS

This study demonstrated a relationship between sunlight exposure and eye disorders in an economically active population. Women were found to be especially vulnerable to pterygium. However, additional prospective studies to clarify the pathophysiology of pterygium are needed.

An automatic sleep disorder detection based on EEG cross-frequency coupling and random forest model

Objective. Sleep disorders are medical disorders of a subject's sleep architecture and based on their severity, they can interfere with mental, emotional and physical functioning. The most common ones are insomnia, narcolepsy, sleep apnea, bruxism, etc. There is an increased risk of developing sleep disorders in elderly like insomnia, periodic leg movements, rapid eye movement behavior disorders, sleep disorder breathing, etc. Consequently, their accurate diagnosis and classification are important steps towards an early stage treatment that could save the life of a patient.Approach. The electroencephalographic (EEG) signal is the most sensitive and important biosignal, which is able to capture the brain sleep activity that is sensitive to sleep. In this study, we attempt to analyze EEG sleep activity via complementary cross-frequency coupling (CFC) estimates, which further feed a classifier, aiming to discriminate sleep disorders. We adopted an open EEG database with recordings that were grouped into seven sleep disorders and a healthy control. The EEG brain activity from common sensors has been analyzed with two basic types of CFC.Main results. Finally, a random forest (RF) classification model was built on CFC patterns, which were extracted from non-cyclic alternating pattern epochs. Our RF^CFCmodel achieved a 74% multiclass accuracy. Both types of CFC, phase-to-amplitude and amplitude-amplitude coupling patterns contribute to the accuracy of the RF model, thus supporting their complementary information.Significance. CFC patterns, in conjunction with the RF classifier proved a valuable biomarker for the classification of sleep disorders.

Workshop report. Circadian rhythm sleep-wake disorders: gaps and opportunities

This White Paper presents the results from a workshop cosponsored by the Sleep Research Society (SRS) and the Society for Research on Biological Rhythms (SRBR) whose goals were to bring together sleep clinicians and sleep and circadian rhythm researchers to identify existing gaps in diagnosis and treatment and areas of high-priority research in circadian rhythm sleep-wake disorders (CRSWD). CRSWD are a distinct class of sleep disorders caused by alterations of the circadian time-keeping system, its entrainment mechanisms, or a misalignment of the endogenous circadian rhythm and the external environment. In these disorders, the timing of the primary sleep episode is either earlier or later than desired, irregular from day-to-day, and/or sleep occurs at the wrong circadian time. While there are incomplete and insufficient prevalence data, CRSWD likely affect at least 800,000 and perhaps as many as 3 million individuals in the United States, and if Shift Work Disorder and Jet Lag are included, then many millions more are impacted. The SRS Advocacy Taskforce has identified CRSWD as a class of sleep disorders for which additional high-quality research could have a significant impact to improve patient care. Participants were selected for their expertise and were assigned to one of three working groups: Phase Disorders, Entrainment Disorders, and Other. Each working group presented a summary of the current state of the science for their specific CRSWD area, followed by discussion from all participants. The outcome of those presentations and discussions are presented here.

Effect of a Multimodal Lifestyle Intervention on Sleep and Cognitive Function in Older Adults with Probable Mild Cognitive Impairment and Poor Sleep: A Randomized Clinical Trial

BACKGROUND

Poor sleep is common among older adults with mild cognitive impairment (MCI) and may contribute to further cognitive decline. Whether multimodal lifestyle intervention that combines bright light therapy (BLT), physical activity (PA), and good sleep hygiene can improve sleep in older adults with MCI and poor sleep is unknown.

OBJECTIVE

To assess the effect of a multimodal lifestyle intervention on sleep in older adults with probable MCI and poor sleep.

METHODS

This was a 24-week proof-of-concept randomized trial of 96 community-dwelling older adults aged 65-85 years with probable MCI (<26/30 on the Montreal Cognitive Assessment) and poor sleep (>5 on the Pittsburgh Sleep Quality Index [PSQI]). Participants were allocated to either a multimodal lifestyle intervention (INT); or 2) education + attentional control (CON). INT participants received four once-weekly general sleep hygiene education classes, followed by 20-weeks of: 1) individually-timed BLT; and 2) individually-tailored PA promotion. Our primary outcome was sleep efficiency measured using the MotionWatch8© (MW8). Secondary outcomes were MW8-measured sleep duration, fragmentation index, wake-after-sleep-onset, latency, and PSQI-measured subjective sleep quality.

RESULTS

There were no significant between-group differences in MW8 measured sleep efficiency at 24-weeks (estimated mean difference [INT -CON]: 1.18%; 95% CI [-0.99, 3.34]), or any other objective-estimate of sleep. However, INT participants reported significantly better subjective sleep quality at 24-weeks (estimated mean difference: -1.39; 95% CI [-2.72, -0.06]) compared to CON.

CONCLUSION

Among individuals with probable MCI and poor sleep, a multimodal lifestyle intervention improves subjective sleep quality, but not objectively estimated sleep.

New approaches to symptomatic treatments for Alzheimer's disease

BACKGROUND

Successful development of agents that improve cognition and behavior in Alzheimer's disease (AD) is critical to improving the lives of patients manifesting the symptoms of this progressive disorder.

DISCUSSION

There have been no recent approvals of cognitive enhancing agents for AD. There are currently 6 cognitive enhancers in Phase 2 trials and 4 in phase 3. They represent a variety of novel mechanisms. There has been progress in developing new treatments for neuropsychiatric symptoms in AD with advances in treatment of insomnia, psychosis, apathy, and agitation in AD. There are currently 4 AD-related psychotropic agents in Phase 2 trials and 7 in Phase 3 trials. Many novel mechanisms are being explored for the treatment of cognitive and behavioral targets. Progress in trial designs, outcomes measures, and population definitions are improving trial conduct for symptomatic treatment of AD.

CONCLUSIONS

Advances in developing new agents for cognitive and behavioral symptoms of AD combined with enhanced trial methods promise to address the unmet needs of patients with AD for improved cognition and amelioration of neuropsychiatric symptoms.

Prevalence and associated factors of circadian rhythm sleep-wake disorders and insomnia among visually impaired Japanese individuals

BACKGROUND

Although earlier studies have demonstrated that circadian rhythm sleep-wake disorders (CRSWD) are more prevalent in visually impaired individuals, the actual prevalence of CRSWD and insomnia among the visually impaired Japanese population remains unclear. The aim of this cross-sectional, telephone-based study was to estimate the prevalence of CRSWD and insomnia, and explore factors associated with CRSWD and insomnia among visually impaired Japanese individuals.

METHODS

A nationwide telephone survey was conducted among visually-impaired individuals through local branches of the Japan Federation of the Blind. In total, 157 visually impaired individuals were eligible for this study. Demographic information and information about visual impairments, lifestyle, and sleep patterns were assessed using questionnaires and subsequent telephone interviews. CRSWD and insomnia were defined according to the International Classification of Sleep Disorders-Third Edition criteria.

RESULTS

The prevalence of CRSWD in visually impaired individuals was 33.1%. Among those with CRSWD, a non-24-h/irregular sleep-wake rhythm type was the most frequently observed (26.8%), followed by an advanced sleep-wake phase type and a delayed sleep-wake phase type (3.8 and 2.5%, respectively). Furthermore, 28.7% of the visually impaired individuals were found to have insomnia. In the visually impaired individuals, the absence of light perception, unemployment, living alone, and use of hypnotics were significantly associated with CRSWD, whereas only the use of hypnotics was extracted as a marginally associated factor of insomnia.

CONCLUSIONS

CRSWD and insomnia were highly prevalent in visually impaired Japanese individuals. The presence of CRSWD among the visually impaired individuals was associated with a lack of light perception and/or social zeitgebers.

Determinants of sleep quality in college students: A literature review

PURPOSE

To review the various determinants of sleep quality among college students.

METHODS

The PubMed, Web of Science and Cochrane Library databases were searched with the search string "sleep quality" AND "college students" for articles published between January 2007 and October 2017. Articles were excluded if they (1) examined sleep quality as a risk factor for other outcomes or (2) involved inpatients or participants under medical care.

RESULTS

The 112 identified studies were classified into categories according to the investigated determinants and their effect on sleep quality. Physical activity and healthy social relations improved sleep quality, while caffeine intake, stress and irregular sleep-wake patterns decreased sleep quality. Less consistent results were reported regarding eating habits and sleep knowledge, while proper napping during the day might improve overall sleep quality.

CONCLUSIONS

College students are vulnerable to different risk factors for sleep quality. When designing interventions to improve sleep quality among college students, the main determinants need to be taken into consideration.

Tailored music listening intervention to reduce sleep disturbances in older adults with dementia: Research protocol

Sleep disruption in older adults living with Alzheimer's disease and related dementias (ADRD) is debilitating and contributes to increased institutionalization, reduced cognitive function, and accelerated disease progression. Furthermore, sleep disruption is linked to poor health outcomes in caregivers, such as decreased quality of life and increased caregiver burden. Given the potentially harmful side effects of pharmacologic treatment, nonpharmacologic approaches, such as music, may provide a safer alternative to reducing sleep disruption in this vulnerable population. A growing body of literature suggests that calming tailored music may improve sleep quality in older adults with memory loss, but its efficacy has not been demonstrated in older adults with ADRD in the community, where most older adults with ADRD live. If shown to be feasible and acceptable, tailored music interventions can then be tested for efficacy in reducing sleep disruption. This protocol details a wait-list randomized controlled trial (NCT04157244), the purpose of which is to test the feasibility, acceptability, and examine the preliminary efficacy of a tailored music listening intervention in older adults with ADRD who report sleep disruption. Music selections will be tailored to the music genre preferences of older adults with ADRD and account for known sleep-inducing properties. The feasibility of processes that is key to the success of the subsequent study will be examined. Preliminary efficacy of the intervention will be assessed using objective (actigraphy) and subjective (proxy-reported) sleep quality measures. In addition, qualitative data will be solicited, examining the acceptability and satisfaction with the intervention by individuals with ADRD.

Multidimensional sleep quality of dependent self-employment workers

Background

The number of workers in non-standard employment (NSE) is increasing due to industrial change and technological development. Dependent self-employment (DSE), a type of NSE, was created decades ago. Despite the problems associated with this new type of employment, few studies have been conducted on the effects by DSE on health, especially sleep quality. This study aims to determine the relationship between DSE and sleep quality.

Methods

This study analyzed data of 50,250 wage workers from the fifth Korean Working Conditions Survey. Workers that did not respond or refused to answer any questions related to variables were excluded, and finally 36,709 participants were included in this study. A total of 2,287 workers (6.2%) were compared with non-DSE (34,422; 93.8%) workers, and multiple logistic regression analyses were applied.

Results

DSE status had a significant association with difficulty falling asleep (odds ratio [OR]: 1.331, 95% confidence interval [CI]: 1.178–1.504), difficulty maintaining sleep (OR: 1.279; 95% CI: 1.125–1.455), and extreme fatigue after waking up (OR: 1.331; 95% CI: 1.184–1.496). A multiple logistic regression of the variables for sleep quality in DSE showed a significant association with exposure to physical factors for all types of poor sleep quality as well as shift work for difficulty maintaining sleep with extreme fatigue after waking up. Long working hours and emotional labor were also associated with extreme fatigue after waking up.

Conclusions

This study shows a significant association between DSE and poor sleep quality, especially when workers were exposed to physical risk factors (noise, vibration, abnormal temperature, etc.) and shift work.

Dysregulation of Circadian Rhythms in Autism Spectrum Disorders

Background:

The alterations in neurological and neuroendocrine functions observed in the autism spectrum disorder (ASD) involves environmentally dependent dysregulation of neurodevelopment, in interaction with multiple coding gene defects. Disturbed sleep-wake patterns, as well as abnormal melatonin and glucocorticoid secretion, show the relevance of an underlying impairment of the circadian timing system to the behavioral phenotype of ASD. Thus, understanding the mechanisms involved in the circadian dysregulation in ASD could help to identify early biomarkers to improve the diagnosis and therapeutics as well as providing a significant impact on the lifelong prognosis.

Objective:

In this review, we discuss the organization of the circadian timing system and explore the connection between neuroanatomic, molecular, and neuroendocrine responses of ASD and its clinical manifestations. Here we propose interconnections between circadian dysregulation, inflammatory baseline and behavioral changes in ASD. Taking into account, the high relevancy of melatonin in orchestrating both circadian timing and the maintenance of physiological immune quiescence, we raise the hypothesis that melatonin or analogs should be considered as a pharmacological approach to suppress inflammation and circadian misalignment in ASD patients.

Strategy:

This review provides a comprehensive update on the state-of-art of studies related to inflammatory states and ASD with a special focus on the relationship with melatonin and clock genes. The hypothesis raised above was analyzed according to the published data.

Conclusion:

Current evidence supports the existence of associations between ASD to circadian dysregulation, behavior problems, increased inflammatory levels of cytokines, sleep disorders, as well as reduced circadian neuroendocrine responses. Indeed, major effects may be related to a low melatonin rhythm. We propose that maintaining the proper rhythm of the circadian timing system may be helpful to improve the health and to cope with several behavioral changes observed in ASD subjects.

β-Arrestin 1 (ARRB1) serves as a molecular marker of the peripheral circadian rhythm

The control of the circadian rhythm is important for health because it regulates physiological functions and is associated with health hazards. We aimed to identify a circadian biomarker of health status in human saliva, since collecting saliva is non-invasive, straightforward, and cost-effective. Among 500 genes potentially controlled by the salivary clock identified using chromatin immunoprecipitation (ChIP) assays, 22 of them showed reasonable transcriptional responses according to a DNA array in a salivary model system. Among these 22 genes, ARRB1, which is expressed in human salivary glands, was also expressed in model HSG cells at the transcriptional and translational levels. The profile of ARRB1 expression in human saliva was circadian, suggesting that ARRB1 could serve as a candidate circadian biomarker in saliva. We compared ARRB1 with other biomarkers in salivary samples from jet-lagged individuals. The circadian profile of ARRB1 reflected the time lag more than the profile of melatonin, whereas the profiles of cortisol and α-amylase did not reflect the time lag. Overall, these findings suggest that salivary ARRB1 could serve as a candidate biomarker that could be used to monitor the internal body clock.

Working Time Society consensus statements: Evidence-based effects of shift work on physical and mental health

Potential effects of shift work on health are probably related to the misalignment between the light-dark cycle and the human activity-rest cycle. Light exposure at night mediates these effects, including social misalignment and leads to an inversion of activity and rest, which, in turn, is linked to changes in behaviours. This article reviews the epidemiological evidence on the association between shift work and health, and possible mechanisms underlying this association. First, evidence from findings of the meta-analyses and systematic reviews published in the last 10 yr is presented. In addition, it reports the larger single-occupation studies and recent large population-based studies of the general workforce. Koch's postulates were used to evaluate the evidence related to the development of disease as a result of exposure to shift work. Finally, we discussed limitations of the multiple pathways that link shift work with specific disorders and the methodological challenges facing shift work research. We concluded that the clearest indications of shift work being the cause of a disease are given when there is a substantial body of evidence from high quality field studies showing an association and there is good evidence from laboratory studies supporting a causal explanation of the link.

Circadian disruption and human health: A bidirectional relationship

Circadian rhythm disorders have been classically associated with disorders of abnormal timing of the sleep-wake cycle, however circadian dysfunction can play a role in a wide range of pathology, ranging from the increased risk for cardiometabolic disease and malignancy in shift workers, prompting the need for a new field focused on the larger concept of circadian medicine. The relationship between circadian disruption and human health is bidirectional, with changes in circadian amplitude often preceding the classical symptoms of neurodegenerative disorders. As our understanding of the importance of circadian dysfunction in disease grows, we need to develop better clinical techniques for identifying circadian rhythms and also develop circadian based strategies for disease management. Overall this review highlights the need to bring the concept of time to all aspects of medicine, emphasizing circadian medicine as a prime example of both personalized and precision medicine.

Systematic Review of Sleep Disturbances and Circadian Sleep Desynchronization in Autism Spectrum Disorder: Toward an Integrative Model of a Self-Reinforcing Loop

Background: A compelling number of studies, conducted in both children and adults, have reported an association between sleep disturbances/circadian sleep alterations and autism spectrum disorder (ASD); however, the data are sparse and the nature of this link is still unclear. The present review aimed to systematically collect the literature data relevant on sleep disturbances and circadian sleep dysrhythmicity related to ASD across all ages and to provide an integrative theoretical framework of their association. Methods: A systematic review of the MEDLINE, PubMed, and Cochrane databases was conducted from November 2018 to February 2019. The search strategies used were MeSH headings and keywords for "sleep-wake circadian rhythms" OR "circadian sleep disorders" OR "sleep-wake pattern" OR "sleep disorders" OR "melatonin" AND "autism spectrum disorder" OR "autism". Results: One hundred and three studies were identified, 15 regarded circadian sleep dysrhythmicity, 74 regarded sleep disturbances, and 17 regarded melatonin alterations in children and adults with ASD. Our findings suggested that autistic subjects frequently present sleep disturbances in particular short sleep duration, low sleep quality/efficiency, and circadian sleep desynchronization such as delayed phases and/or eveningness. Sleep disturbances and circadian sleep alterations have been related to the severity of autistic symptoms. Genetic studies have shown polymorphisms in circadian CLOCK genes and in genes involved in melatonin pathways in subjects with ASD. Conclusions: Sleep disturbances and circadian sleep alterations are frequent in subjects with autistic symptoms. These subjects have shown polymorphisms in clock genes expression and in genes involved in melatonin production. The impairment of circadian sleep regulation may increase the individual's vulnerability to develop symptoms of ASD by altering the sleep regulation in toto, which plays a key role in normal brain development. Even though controversies and "research gaps" are present in literature at this point, we may hypothesize a bidirectional relation between circadian sleep dysfunction and ASD. In particular, circadian sleep dysrhythmicity may predispose to develop ASD symptoms and vice versa within a self-reinforcing feedback loop. By targeting sleep disturbances and circadian sleep dysrhythmicity, we may improve treatment strategies for both children and adults with ASD.

Buying time: a proof-of-concept randomized controlled trial to improve sleep quality and cognitive function among older adults with mild cognitive impairment

BACKGROUND

Current evidence suggests that good quality sleep is associated with preserved cognitive function and reduced dementia risk in older adults. Sleep complaints are especially common among older adults with mild cognitive impairment (MCI), and this may contribute to their increased risk for progression to dementia. Thus, improving their sleep may be important for maintaining their cognitive health. Chronotherapy is a set of intervention strategies that can improve sleep quality through strengthening the entrainment of the biological clock to the solar light-dark cycle, and includes strategies such as (1) bright light therapy (BLT); (2) physical activity (PA); and (3) good sleep hygiene. Of these strategies, BLT is the most potent and is based on providing individualized timing to entrain circadian rhythms. Thus, a personalized chronotherapy intervention of individually timed BLT and individually tailored PA promotion, in conjunction with general sleep hygiene education may promote older adult sleep quality. We therefore aim to carry out a proof-of-concept randomized controlled trial (RCT) to examine the efficacy of such a personalized chronotherapy intervention to improve sleep quality among older adults with MCI.

METHODS/DESIGN

This was a 24-week RCT of a personalized chronotherapy intervention aimed to primarily improve sleep quality as measured by the MotionWatch8©. Participants in the personalized chronotherapy group (INT) will receive four once-weekly, general sleep hygiene education classes, followed by 20 weeks of (1) individually timed BLT and (2) bi-weekly, individually tailored PA counseling phone calls in conjunction with receiving a consumer-available PA tracker-the Fitbit® Flex™. Ninety-six adults (aged 65-85 years) classified as having MCI (i.e., Mini-Mental State Exam (MMSE) ≥ 24; Montreal Cognitive Assessment (MoCA) ≤ 26; without dementia or significant functional impairment) will be randomized to either INT or a waitlist control group (CON).

DISCUSSION

The results of this trial will help determine if a personalized chronotherapy intervention that includes individually timed BLT and individually tailored PA promotion, along with general sleep hygiene education can promote sleep quality among older adults at increased risk for dementia. Our results will help inform best practices for promoting sleep quality among older adults with MCI.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02926157 . Registered on 6 October 2016.

The Relation between Sleep Disruption and Cataract in a Large Population-Based Study

PURPOSE

To investigate the relation between sleep disruption and nuclear cataract, as well as the impact of cataract removal on sleep, in two discrete population-based cohorts.

METHODS

This is a cross-sectional study of 5070 participants from three large longitudinal epidemiologic studies of age-related eye disease, hearing, olfaction, and cognition. Slit-lamp photos of the lens were obtained to grade nuclear cataract using a standardized protocol. The quality of sleep was assessed using a modified Wisconsin Sleep Cohort Study questionnaire. Multiple linear regression analyses were used to assess the associations between levels of nuclear cataract/cataract extraction and the number of sleep problems. Systemic co-morbidity data were included as potential confounders, including diabetes mellitus, obesity, hypertension, cerebrovascular disease, thyroid disease, tobacco and alcohol use, and physical component summary score and mental component summary score.

RESULTS

The mean age of the cohort was 57.6 years (range 22-95 years). The majority of the cohort demonstrated nuclear cataract levels 2 or 3 (36.8% and 30.1%, respectively). A total of 8% of the cohort had an intraocular lens (IOL) in at least one eye. There was no statistically significant correlation between sleep problems with presence of either nuclear cataract or IOL implant (p > 0.05).

CONCLUSION

In this cross-sectional, population-based study, we found no significant association between nuclear cataract or presence of IOL with poor sleep quality after adjusting for potential confounders. Studies of the longitudinal impact of nuclear cataract and cataract removal on sleep are needed to elucidate the role of nuclear cataract and cataract removal on sleep.

A Qualitative Study of Sleep-Wake Disturbance Among Veterans With Post-Acute Moderate to Severe Traumatic Brain Injury

OBJECTIVE

Examine sleep-wake disturbance (SWD) characteristics, factors, consequences, and management strategies from the perspective of veterans with chronic stage, moderate/severe traumatic brain injury (TBI).

SETTING

VA Medical Center, Rocky Mountain.

US PARTICIPANTS

Nineteen male veterans with post-acute TBI and SWD in the VA Health Administration.

DESIGN

Qualitative descriptive.

MEASURES

Semistructured interviews, Ohio State University TBI-Identification Method, Insomnia Severity Index.

RESULTS

Two main dimensions emerged: "Messed up sleep" and Surviving and Managing SWD. Sleep-wake disturbance has long-term multidimensional features, etiology, consequences, and practice implications. Although SWD may not be consistently discussed with providers, the problem appears to be pervasive in many aspects of the lives of the informants. Difficulty falling asleep, frequent awakenings, and poor sleep quality were common symptoms that were described as intrusive, isolating, and difficult to self-manage. Veterans discussed a host of physical symptoms, mental health issues, environmental, and behavioral factors that contributed to SWD. Medications, sleep apnea treatment, and self-imposed isolation were frequent management strategies. Veterans expressed a willingness to try new approaches and work with providers.

CONCLUSION

Sleep-wake disturbance among veterans with chronic stage TBI is a multidimensional phenomenon with interplay between comorbidities, contributing factors, effects on functioning, and sleep management strategies. Implications for practice include early and routine evaluation, monitoring, and treatment of SWD. Research is needed to test interventions that address SWD and common TBI comorbidities.

Melatonin in Tuberous Sclerosis Complex Analysis Using Modern Mathematical Modeling Methods

Purpose. The aim of the study was to assess melatonin secretion pattern in children with TSC and to compare it with the secretion patterns in children with and without epilepsy. Material and Methods. Melatonin secretion was measured every three hours using the RIA method in four children with recognized TSC. The parameters of the melatonin secretion models were interpreted and compared with those obtained for the patients with epilepsy (n = 76) and the children from the control, nonepileptic group (n = 36). To describe the diurnal melatonin secretion, mathematical model was constructed and nonlinear least squares method with the Levenberg-Marquardt optimization algorithm was applied to approximate its parameters. The dim light melatonin onset (DLMO) parameters were also estimated from the model. Results and Conclusions. Statistically significant differences were found between the TSC melatonin secretion profiles and the nonepileptic control group. The profiles for the epileptic and TSC groups were found to be similar. For the TSC group, though a small one, the variations in the MLT release amplitudes seem to be independent of the total number of seizures; however, the MLT release shift appears to depend on the number of seizures.

Melatonin in Epilepsy: A New Mathematical Model of Diurnal Secretion

Purpose. The main objective of the study was to create a mathematical model that describes the melatonin circadian secretion and, then the functionality of the model was tested by a comparison of the melatonin secretions in children with and without epilepsy. Material and Methods. The patients were divided into the epilepsy group (EG, n = 52) and the comparison group (CG, n = 30). The melatonin level was assessed by a radioimmunoassay method. The diurnal melatonin secretion was described using a nonlinear least squares method. Spearman's rank correlation coefficient was chosen to estimate the dependence of the acquired data. The model reproduces blood concentration profiles and its parameters were statistically analyzed using the Mann-Whitney-Wilcoxon test and logistic regression. Results. The correlation analysis performed for the EG and CG groups showed moderate correlations between age and the melatonin secretion model parameters. Patients with epilepsy are characterized by an increased phase shift of melatonin release.

Irregular Sleep-Wake Rhythm Disorder

Irregular sleep-wake rhythm disorder is a circadian rhythm disorder characterized by multiple bouts of sleep within a 24-hour period. Patients present with symptoms of insomnia, including difficulty either falling or staying asleep, and daytime excessive sleepiness. The disorder is seen in a variety of individuals, ranging from children with neurodevelopmental disorders, to patients with psychiatric disorders, and most commonly in older adults with neurodegenerative disorders. Treatment of irregular sleep-wake rhythm disorder requires a multimodal approach aimed at strengthening circadian synchronizing agents, such as daytime exposure to bright light, and structured social and physical activities. In addition, melatonin may be useful in some patients.

Aging and Circadian Rhythms

Aging is associated with numerous changes, including changes in sleep timing, duration, and quality. The circadian timing system interacts with a sleep-wake homeostatic system to regulate human sleep, including sleep timing and structure. This article reviews key features of the human circadian timing system, age-related changes in the circadian timing system, and how those changes may contribute to the observed alterations in sleep.

Mother-infant circadian rhythm: development of individual patterns and dyadic synchrony

BACKGROUND

Mutual circadian rhythm is an early and essential component in the development of maternal-infant physiological synchrony.

AIMS

The aim of this to examine the longitudinal pattern of maternal-infant circadian rhythm and rhythm synchrony as measured by rhythm parameters.

STUDY DESIGN

In-home dyadic actigraphy monitoring at infant age 4, 8, and 12 weeks.

SUBJECTS

Forty-three healthy mother-infant pairs.

OUTCOME MEASURES

Circadian parameters derived from cosinor and non-parametric analysis including mesor, magnitude, acrophase, L5 and M10 midpoints (midpoint of lowest 5 and highest 10h of activity), amplitude, interdaily stability (IS), and intradaily variability (IV).

RESULTS

Mothers experienced early disruption of circadian rhythm, with re-establishment of rhythm over time. Significant time effects were noted in increasing maternal magnitude, amplitude, and IS and decreasing IV (p<.001). Infants demonstrated a developmental trajectory of circadian pattern with significant time effects for increasing mesor, magnitude, amplitude, L5, IS, and IV (p<.001). By 12 weeks, infant phase advancement was evidenced by mean acrophase and M10 midpoint occurring 60 and 43 min (respectively) earlier than at 4 weeks. While maternal acrophase remained consistent over time, infants became increasingly phase advanced relative to mother and mean infant acrophase at 12 weeks occurred 60 min before mother. Mother-infant synchrony was evidenced in increasing correspondence of acrophase at 12 weeks (r=0.704), L5 (r=0.453) and M10 (r=0.479) midpoints.

CONCLUSIONS

Development of mother-infant synchrony reflects shared elements of circadian rhythm.

Circadian rhythm sleep disorders

There have been remarkable advances in our understanding of the molecular, cellular, and physiologic mechanisms underlying the regulation of circadian rhythms, and of the impact of circadian dysfunction on health and disease. This information has transformed our understanding of the effect of circadian rhythm sleep disorders (CRSD) on health, performance, and safety. CRSDs are caused by alterations of the central circadian timekeeping system, or a misalignment of the endogenous circadian rhythm and the external environment. This article reviews circadian biology and discusses the pathophysiology, clinical features, diagnosis, and treatment of the most commonly encountered CRSDs in clinical practice.

Biological and psychological rhythms: an integrative approach to rhythm disturbances in autistic disorder

Biological rhythms are crucial phenomena that are perfect examples of the adaptation of organisms to their environment. A considerable amount of work has described different types of biological rhythms (from circadian to ultradian), individual differences in their patterns and the complexity of their regulation. In particular, the regulation and maturation of the sleep-wake cycle have been thoroughly studied. Its desynchronization, both endogenous and exogenous, is now well understood, as are its consequences for cognitive impairments and health problems. From a completely different perspective, psychoanalysts have shown a growing interest in the rhythms of psychic life. This interest extends beyond the original focus of psychoanalysis on dreams and the sleep-wake cycle, incorporating central theoretical and practical psychoanalytic issues related to the core functioning of the psychic life: the rhythmic structures of drive dynamics, intersubjective developmental processes and psychic containment functions. Psychopathological and biological approaches to the study of infantile autism reveal the importance of specific biological and psychological rhythmic disturbances in this disorder. Considering data and hypotheses from both perspectives, this paper proposes an integrative approach to the study of these rhythmic disturbances and offers an etiopathogenic hypothesis based on this integrative approach.

Circadian rhythm abnormalities

PURPOSE

This article reviews the recent advances in understanding of the fundamental properties of circadian rhythms and discusses the clinical features, diagnosis, and treatment of circadian rhythm sleep disorders (CRSDs).

RECENT FINDINGS

Recent evidence strongly points to the ubiquitous influence of circadian timing in nearly all physiologic functions. Thus, in addition to the prominent sleep and wake disturbances, circadian rhythm disorders are associated with cognitive impairment, mood disturbances, and increased risk of cardiometabolic disorders. The recent availability of biomarkers of circadian timing in clinical practice has improved our ability to identify and treat these CRSDs.

SUMMARY

Circadian rhythms are endogenous rhythms with a periodicity of approximately 24 hours. These rhythms are synchronized to the physical environment by social and work schedules by various photic and nonphotic stimuli. CRSDs result from a misalignment between the timing of the circadian rhythm and the external environment (eg, jet lag and shift work) or a dysfunction of the circadian clock or its afferent and efferent pathways (eg, delayed sleep-phase, advanced sleep-phase, non-24-hour, and irregular sleep-wake rhythm disorders). The most common symptoms of these disorders are difficulties with sleep onset and/or sleep maintenance and excessive sleepiness that are associated with impaired social and occupational functioning. Effective treatment for most of the CRSDs requires a multimodal approach to accelerate circadian realignment with timed exposure to light, avoidance of bright light at inappropriate times, and adherence to scheduled sleep and wake times. In addition, pharmacologic agents are recommended for some of the CRSDs. For delayed sleep-phase, non-24-hour, and shift work disorders, timed low-dose melatonin can help advance or entrain circadian rhythms; and for shift work disorder, wake-enhancing agents such as caffeine, modafinil, and armodafinil are options for the management of excessive sleepiness.

Classification of sleep disorders

The classification of sleep disorders is necessary to discriminate between disorders and to facilitate an understanding of symptoms, etiology, and pathophysiology that allows for appropriate treatment. The earliest classification systems, largely organized according to major symptoms (insomnia, excessive sleepiness, and abnormal events that occur during sleep), were unable to be based on pathophysiology because the cause of most sleep disorders was unknown. These 3 symptom-based categories are easily understood by physicians and are therefore useful for developing a differential diagnosis. The International Classification of Sleep Disorders, version 2, published in 2005 and currently undergoing revision, combines a symptomatic presentation (e.g., insomnia) with 1 organized in part on pathophysiology (e.g., circadian rhythms) and in part on body systems (e.g., breathing disorders). This organization of sleep disorders is necessary because of the varied nature and because the pathophysiology for many of the disorders is still unknown. The International Classification of Sleep Disorders, version 2 provides relevant diagnostic and epidemiological information on sleep disorders to more easily differentiate between the disorders.

Melatonin profile and its relation to circadian rhythm sleep disorders in Angelman syndrome patients

BACKGROUND

Sleep problems are known to be common in Angelman syndrome (AS), a neurodevelopmental disorder which is associated with an abnormality of chromosome 15q11-q13. However, the circadian aspect of sleep disorders in AS and an effective treatment for the disorder have yet to be established.

METHODS

We elucidated the sleep-wake patterns of AS patients and its relationship to the serum melatonin levels. The serum melatonin levels of 15 AS patients were measured every 4h for one day and the values were compared with those of age-matched controls. We also examined the effectiveness of the oral administration of melatonin on AS patients with circadian rhythm sleep disorders (CRSD).

RESULTS

A total of eight of the 15 AS patients had CRSD (irregular sleep-wake type, n=4; free-running type n=2; delayed sleep phase type, n=2). The nighttime serum melatonin levels of the AS patients were significantly lower than those of the controls at the measured time points during the night. The nocturnal melatonin levels were comparably low both in AS patients with and without CRSD except for the cases with delayed sleep phase type, which showed normal but delayed peak melatonin level. Six out of eight CRSD cases were given a daily dose of 1mg of melatonin between 18:00 and 19:00 regularly for three months. After receiving the treatment, the sleep patterns improved in four cases.

CONCLUSION

This study revealed a high prevalence of CRSD in AS patients, which may be related to abnormal serum melatonin profiles.

The role of self-regulation in predicting sleep hygiene in university students

University students have poor sleep hygiene, leading to poorer health. Facets of self-regulation such as planning, behavioural inhibition, cognitive flexibility and working memory were explored in relation to three sleep hygiene behaviours: Avoiding stress or anxiety before bed, avoiding going to bed hungry or thirsty, and making the bedroom restful. One hundred and thirty-seven participants took part in an Internet-based survey over two time points separated by a period of two weeks. Only cognitive flexibility and behavioural inhibition correlated with sleep hygiene. Cognitive flexibility significantly predicted an aspect of sleep hygiene after controlling for past behaviour. However, when past behaviour was controlled for, behavioural inhibition no longer predicted sleep hygiene. Thus, cognitive flexibility may play a role in explaining sleep hygiene; however, behavioural inhibition does not appear as important as previously assumed. Further research could build on this study to determine whether cognitive flexibility can be experimentally improved.