Actigraphy in the assessment of insomnia: a quantitative approach

Insomnia Symptoms Are Associated with Measures of Functional Deterioration and Dementia Status in Adults with Down Syndrome at High Risk for Alzheimer's Disease

Background

While obstructive sleep apnea (OSA) and insomnia symptoms in neurotypical populations are associated with Alzheimer's disease (AD), their association with dementia in adults with Down syndrome (DS) remains less clear, even though these symptoms are prevalent and treatable in DS. Understanding their associations with AD-related dementia status, cognitive impairment, and functional deterioration may lead to interventions to slow decline or disease progression in adults with DS.

Objective

To characterize differences in OSA and insomnia symptom expression by dementia status, and to determine which sleep factors support dementia diagnosis.

Methods

Multimodal consensus conference was used to determine dementia status in 52 adults with DS (52.2 ± 6.4 years, 21 women). Cognitive impairment, adaptive behavior skills, and symptoms of OSA and insomnia were quantified using validated assessments for adults with DS and their primary informants.

Results

A sex by dementia status interaction demonstrated that older women with DS and dementia had more severe terminal insomnia but not OSA symptoms relative to older women with DS who were cognitively stable (CS). Greater insomnia symptom severity was associated with greater functional impairments in social and self-care domains adjusting for age, sex, premorbid intellectual impairment, and dementia status.

Conclusions

Insomnia symptoms are more severe in women with DS with dementia than in women with DS and no dementia, and regardless of dementia status or sex, more severe insomnia symptoms are associated with greater impairment in activities of daily living. These findings underscore the potential importance of early insomnia symptom evaluation and treatment in women with DS at risk of developing AD.

Activity-Based Prospective Memory in Insomniacs

OBJECTIVE

To investigate the activity-based prospective memory performance in patients with insomnia, divided, on the basis of actigraphic evaluation, into sleep onset, maintenance, mixed and negative misperception insomnia.

METHODS

A total of 153 patients with insomnia (I, 83 females, mean age + SD = 41.37 + 16.19 years) and 121 healthy controls (HC, 78 females, mean age + SD = 36.99 + 14.91 years) wore an actigraph for one week. Insomnia was classified into sleep onset insomnia (SOI), maintenance insomnia (MaI), mixed insomnia (MixI) and negative misperception insomnia (NMI). To study their activity-based prospective memory performance, all the participants were required to push the actigraph event marker button twice, at bedtime (task 1) and at get-up time (task 2).

RESULTS

Only patients with maintenance and mixed insomnia had a significantly lower accuracy in the activity-based prospective memory task at get-up time compared with the healthy controls.

CONCLUSION

The results show that maintenance and mixed insomnia involve an impaired activity-based prospective memory performance, while sleep onset and negative misperception insomnia do not seem to be affected. This pattern of results suggests that the fragmentation of sleep may play a role in activity-based prospective memory efficiency at wake-up in the morning.

Identity Matters for Well-Being: The Longitudinal Associations Between Identity Processes and Well-Being in Adolescents with Different Cultural Backgrounds

Adolescents' identity processes and their levels of well-being are likely to be intertwined. On the one hand, how adolescents cope with the core developmental task of forming their identity has important implications for their well-being. On the other hand, experiencing a condition of well-being can help adolescents consolidate their identity. This longitudinal study adopted a multidimensional and culturally sensitive perspective to unravel how identity processes (i.e., commitment, in-depth exploration, and reconsideration of commitment) in two domains (i.e., educational and interpersonal identity) were developmentally related to multiple indicators of positive well-being (i.e., physical health, subjective, psychological, and social well-being) in adolescents with different cultural backgrounds. Participants were 1396 adolescents (Mage = 15.73, SDage = 1.23, 49.93% females; 20.89% with a migrant background) who completed questionnaires at four-time points across one year. Results of cross-lagged models confirmed the positive reciprocal associations between identity commitment and well-being in all its facets. The nuanced picture of associations of in-depth exploration and reconsideration of commitment with multiple dimensions of well-being highlighted the importance of adopting a multi-dimensional perspective on well-being and a domain-specific approach to identity. Multigroup analyses indicated that the associations between identity commitment in the educational domain and well-being are relevant, especially for adolescents with a migrant background. Overall, this study highlights the centrality of identity processes for adolescents' adaptation and points to a dynamic loop of reciprocal influences at the core of youth positive development.

Opposing brain signatures of sleep in task-based and resting-state conditions

Sleep and depression have a complex, bidirectional relationship, with sleep-associated alterations in brain dynamics and structure impacting a range of symptoms and cognitive abilities. Previous work describing these relationships has provided an incomplete picture by investigating only one or two types of sleep measures, depression, or neuroimaging modalities in parallel. We analyze the correlations between brainwide neural signatures of sleep, cognition, and depression in task and resting-state data from over 30,000 individuals from the UK Biobank and Human Connectome Project. Neural signatures of insomnia and depression are negatively correlated with those of sleep duration measured by accelerometer in the task condition but positively correlated in the resting-state condition. Our results show that resting-state neural signatures of insomnia and depression resemble that of rested wakefulness. This is further supported by our finding of hypoconnectivity in task but hyperconnectivity in resting-state data in association with insomnia and depression. These observations dispute conventional assumptions about the neurofunctional manifestations of hyper- and hypo-somnia, and may explain inconsistent findings in the literature.

Poor sleep is associated with work environment among 10,087 French healthcare workers: Results from a nationwide survey

Poor sleep is a prevalent issue among healthcare workers and can have detrimental effects on their health. Various individual and professional factors, including the work environment, may contribute to poor sleep. However, only a limited number of studies have examined the simultaneous influence of these factors. Hence, we conducted a nationwide survey among graduated healthcare workers in both public and private healthcare facilities in France. The aim was to analyze the association between poor sleep, assessed using the Pittsburgh Sleep Quality Index (>5), and the work environment, evaluated using the Job Content Questionnaire. The study encompassed 10,087 healthcare workers, among whom 6,540 (64.8%) reported experiencing poor sleep. Nurses, health executives, nursing assistants, and other allied healthcare professionals were more likely to experience poor sleep compared to physicians. Through multivariate regression analysis, we identified several aspects of the work environment associated with an increased likelihood of poor sleep. These factors included high speed and quantity of work, high complexity and intensity, high fragmentation and unpredictability, limited decision-making latitude, underutilization of skills, lack of emotional support from colleagues, and sustained workplace bullying. These findings highlight the significance of considering the work environment in addressing sleep issues among healthcare professionals.

Quality of life, fatigue, sleep quality, and mental health in systemic lupus erythematosus patients with a high cardiovascular risk profile

Systemic lupus erythematosus (SLE) patients report worse health-related quality of life (HRQL), fatigue, anxiety, depression, and sleep quality, when compared to the general population and other chronic diseases. Furthermore, cardiometabolic diseases are highly prevalent in SLE and are also associated with these parameters. Thus, it is plausible to suggest that SLE patients with a high cardiovascular risk may report worse results for these parameters. The aim of the study is to describe HRQL, fatigue, anxiety and depression symptoms, and sleep quality in a sample of SLE patients with a high cardiovascular risk profile (i.e., BMI between 25 and 40 kg/m2 and/or dyslipidemia, hypertension, or diabetes). This was a cross-sectional study where patients were assessed for (i) demographic, anthropometric, and disease-related parameters, (ii) HRQL, (iii) fatigue, (iv) anxiety and depression symptoms, and (v) sleep quality. One-hundred patients completed the study; however, only 87 patients were assessed for sleep quality data. Patients averaged 41.7 ± 9 years, and most patients were classified as overweight/obese (87%). SF-36 scores for physical and mental components summary were 51.3 ± 9.6 and 54.2 ± 15.6, respectively, with "bodily pain" and "role emotional" presenting the lower scores. The total SLEQOL score was 105.1 ± 42.0, with lower scores reported for "self-image" and "mood." Fatigue score was 30.8 ± 8.9, and 78% and 93% reported severe symptoms of anxiety and depression, respectively. The average sleep effectiveness was 82.9 ± 6.6%. Sleep latency, total time in bed (TTiB), and total sleep time (TST) were 8.4 ± 8.9, 495.8 ± 79.7, and 409.7 ± 69.9 min, respectively. Patients reported an average of 17.8 ± 6.2 WE, with 4.5 ± 1.5 min duration and a WASO of 77.7 ± 36.6 min. Despite similar HRQL, fatigue, and sleep quality parameters to those reported by other SLE populations, SLE patients with a high cardiovascular risk had a higher prevalence of depression and anxiety. Understanding SLE patients' quality of life and psychological symptoms is of utmost importance to improve disease management. The findings of this study highlight the need for more intensive and global care regarding mental health when considering a high cardiovascular risk in SLE.

The potential of biomarkers for diagnosing insomnia: Consensus statement of the WFSBP Task Force on Sleep Disorders

OBJECTIVES

Thus far, the diagnosis of insomnia is based on purely clinical criteria. Although a broad range of altered physiological parameters has been identified in insomniacs, the evidence to establish their diagnostic usefulness is very limited. Purpose of this WFSBP Task Force consensus paper is to systematically evaluate a series of biomarkers as potential diagnostic tools for insomnia.

METHODS

A newly created grading system was used for assessing the validity of various measurements in establishing the diagnosis of insomnia; these measurements originated from relevant studies selected and reviewed by experts.

RESULTS

The measurements with the highest diagnostic performance were those derived from psychometric instruments. Biological measurements which emerged as potentially useful diagnostic instruments were polysomnography-derived cyclic alternating pattern, actigraphy, and BDNF levels, followed by heart rate around sleep onset, deficient melatonin rhythm, and certain neuroimaging patterns (mainly for the activity of frontal and pre-frontal cortex, hippocampus and basal ganglia); yet, these findings need replication, as well as establishment of commonly accepted methodology and diagnostic cut-off points. Routine polysomnography, EEG spectral analysis, heart rate variability, skin conductance, thermoregulation, oxygen consumption, HPA axis, and inflammation indices were not shown to be of satisfactory diagnostic value.

CONCLUSIONS

Apart from psychometric instruments which are confirmed to be the gold standard in diagnosing insomnia, six biomarkers emerge as being potentially useful for this purpose.

Efficacy of mind-body therapies for sleep disturbance in patients with early-stage cancer: A systematic review and network meta-analysis

OBJECTIVE

To evaluate and compare the efficacy of different mind-body therapies (MBTs) for sleep disturbance in patients with early-stage cancer.

METHODS

Randomised controlled trials that included patients (aged ≥18 years) with early stage cancer who underwent MBTs (mindfulness, hypnosis, relaxation, yoga, and qigong) were searched in the CINAHL via the EBSCO Host, Cochrane Library, Embase, MEDLINE, PsycINFO, PubMed, and Scopus databases, from the date of database inception to October 2022. The outcomes were subjective sleep disturbance and objective sleep efficiency. Network meta-analysis (NMA) and comparative effects ranking were performed using STATA (v14.0; STATACorp, College Station, TX, USA).

RESULTS

Forty-seven studies investigating five MBTs were included in the NMA. For cancer patients receiving active treatment, mindfulness demonstrated the largest effect size in reducing subjective sleep disturbance (standardised mean difference [SMD]: 0.85; 95% confidence intervals [CI]: 0.20-1.50; Grading of Recommendations Assessment, Development, and Evaluation assessment: moderate), and had the highest cumulative probability compared to usual care or waitlist. For cancer patients who had completed active treatment, qigong demonstrated the largest effect size in reducing subjective sleep disturbance (SMD: 0.99; 95% CI: 0.35-1.63; GRADE: low), followed by hypnosis (SMD: 0.87; 95% CI: 0.32-1.42; GRADE: moderate), and mindfulness (SMD: 0.42; 95% CI: 0.24-0.59; GRADE: moderate). Qigong also demonstrated the largest effect size in improving objective sleep efficiency (weighted mean differences: 10.76; 95% CI: 2.01-19.50; GRADE: low); however, the effect of qigong was tested in only one study in this NMA. Among the eight different treatment conditions, cognitive behavioral therapy (CBT) showed the highest cumulative probability (surface under the cumulative ranking curve: 96.3%) in reducing subjective sleep disturbance and the second highest cumulative probability (SUCRA: 83.3%) in improving objective sleep efficiency.

CONCLUSION

There is no evidence supporting the use of MBTs to replace or be comparable to CBT. Mindfulness can be recommended as an optional treatment for reducing sleep disturbance in patients with early-stage cancer. Some support was observed for qigong and hypnosis in reducing sleep disturbances in patients with early-stage cancer who had completed active treatment. More rigorous trials are warranted to confirm whether different forms of MBTs have different effects on sleep in patients with cancer.

Modification and Validation of a Diagnostic Questionnaire for Restless Legs Syndrome: Modified-Restless Legs Syndrome Diagnostic Questionnaire (m-RLS-DQ)

Background

Diagnostic questionnaire that are available for restless legs syndrome does not include items related to RLS mimics and, hence, increases chances of false positive cases. This study aimed at modification and validation of RLS-diagnostic Questionnaire.

Methods

During modification, additional items were identified, developed, and subjected to evaluation by experts. Experts were requested to validate the content of each item. Based on their responses, content validity indices (average and universal agreement) were calculated. It was then translated to Hindi and validated in a clinical population that included patients with RLS, somatic symptoms disorder, anxiety, other RLS mimics, and osteoarthritis. In addition, a group of healthy controls was also included. Face, concurrent, and discriminant validities were calculated.

Results

Among 209 subjects, nearly 40 subjects had clinical diagnosis of RLS, osteoarthritis, somatic-symptoms-disorder, and anxiety disorder, each. In addition, 16 patients had other RLS mimics (akathisia, varicose veins, BFS, leg-cramps, chronic insomnia) and 30 were healthy controls. After multiple revisions, content validity indices achieved a score of 1 for m-RLS-DQ. Sensitivity and specificity of m-RLS-DQ v. 1.4 for the diagnosis of RLS were 94.9% and 94.1%, respectively. For the diagnosis of RLS, PPV was 78.7%, and NPV was 98.7% with an accuracy of 94.3%. Less than one fourth of participants having chronic insomnia, somatic symptoms disorder, anxiety disorder, and knee osteoarthritis were found to be false positive on m-RLS-DQ; however, none of the healthy controls were found positive on m-RLS-DQ. Concurrent validity with clinical diagnosis of RLS was 0.83 (P < 0.001). Discriminant validity with somatic symptoms disorder was -0.14 (P = 0.03) and with osteoarthritis -0.24 (P < 0.001).

Conclusion

m-RLS-DQ is a valid instrument with acceptable psychometric properties, which can be used for the screening as well as diagnosis of RLS in clinical practice and research studies.

Tackling Insomnia Symptoms through Vestibular Stimulation in Patients with Breast Cancer: A Perspective Paper

Insomnia symptoms are common among patients with breast cancer (BC; 20-70%) and are predictors of cancer progression and quality of life. Studies have highlighted sleep structure modifications, including increased awakenings and reduced sleep efficiency and total sleep time. Such modifications may result from circadian rhythm alterations consistently reported in this pathology and known as carcinogenic factors, including lower melatonin levels, a flattened diurnal cortisol pattern, and lower rest-activity rhythm amplitude and robustness. Cognitive behavioral therapy and physical activity are the most commonly used non-pharmacological interventions to counter insomnia difficulties in patients with BC. However, their effects on sleep structure remain unclear. Moreover, such approaches may be difficult to implement shortly after chemotherapy. Innovatively, vestibular stimulation would be particularly suited to tackling insomnia symptoms. Indeed, recent reports have shown that vestibular stimulation could resynchronize circadian rhythms and improve deep sleep in healthy volunteers. Moreover, vestibular dysfunction has been reported following chemotherapy. This perspective paper aims to support the evidence of using galvanic vestibular stimulation to resynchronize circadian rhythms and reduce insomnia symptoms in patients with BC, with beneficial effects on quality of life and, potentially, survival.

Sleep variability and regularity as contributors to obesity and cardiometabolic health in adolescence

OBJECTIVE

Adolescence is a developmental stage of critical changes in sleep and its circadian timing when the contribution of abnormal sleep variability (amount) and sleep regularity (timing) to obesity and its associated adverse cardiometabolic health outcomes appears to increase. The aim of this study was to summarize findings from studies conducted in adolescents examining both sleep variability and regularity in relation to obesity and cardiometabolic health. Gaps in research and potential causal pathways that future studies should examine are highlighted.

RESULTS

Nightly deviations in sleep duration and sleep midpoint appear to contribute to the development of obesity and associated adverse cardiometabolic outcomes in youth. Studies show that increased sleep variability and irregularity are associated with obesity, decreased physical activity, dysregulated eating and inadequate diet, metabolic dysfunction, impaired cardiac autonomic balance, and elevated blood pressure in adolescents.

CONCLUSIONS

A stable circadian timing of sleep is essential to the overall physical well-being of youth. Emerging evidence supports that sleep variability and circadian misalignment, including sleep irregularity, contribute to adverse obesity-related health outcomes early on in adolescence. Future studies should focus on the underlying behavioral and biological mechanisms in the causal pathway between day-to-day deviations in the amount and timing of sleep and obesity.

The Sleep Parameters of Paralympic Athletes: Characteristics and Assessment Instruments

CONTEXT

Sleep serves many important functions for athletes, particularly in the processes of learning, memory, recovery, and cognition.

OBJECTIVES

Define the sleep parameters of Paralympic athletes and identify the instruments used to assess and monitor sleep Paralympic athletes.

EVIDENCE ACQUISITION

This systematic review was carried out based on the PRISMA guidelines. The survey was conducted in April 2020, the searches were carried out again in September 2021 to check whether there were new scientific publications in the area of sleep and Paralympic sport, searches were performed in the following databases: PubMed, Web of Science, Scopus, SPORTDiscus, Virtual Health Library (BIREME), and SciELO. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time, sleep latency, sleep efficiency, number of awakenings, quality of sleep, daytime sleepiness, and chronotype; the participants were comprised of athletes with disabilities. Studies published at any time in English, Portuguese, and Spanish, were included.

EVIDENCE SYNTHESIS

Data extraction and study selection were performed by 2 researchers independently, and a third author was consulted as necessary. The search returned a total of 407 studies. Following the screening based on exclusion and inclusion criteria, a total of 13 studies were considered. Paralympic athletes have a low amount (7.06 h) of sleep with poor quality and sleep latency (28.05 min), and 57.2% have daytime sleepiness, with the majority belonging to the indifferent chronotype (53, 5%). Moreover, 11 studies assess sleep using subjective instruments (questionnaires), and 2 studies used an objective instrument (actigraphy).

CONCLUSIONS

Sleep disorders are common among Paralympic athletes, poor sleep quality and quantity, and high rates of daytime sleepiness. Subjective methods are most commonly used to assess sleep.

Wearable and mobile technology to characterize daily patterns of sleep, stress, presleep worry, and mood in adolescent insomnia

OBJECTIVES

Characterizing daily patterns of sleep, stress, presleep worry, and mood in adolescents with and without insomnia symptomatology.

DESIGN

Two months of continuous wearable tracking and daily diary ratings.

SETTING

Free-living conditions.

PARTICIPANTS

Ninety-three adolescents (59 girls; 16-19 years old) with (N = 47; 26 with clinical and 21 with sub-clinical) and without (N = 46; control) DSM-5 insomnia symptomatology.

MEASUREMENTS

Fitbit Charge 3 tracked sleep, heart rate, and steps. Evening electronic diaries collected ratings of daily stress, presleep worry, and mood.

RESULTS

While sleep duration (control: 6.88 ± 1.41 hours; insomnia: 6.92 ± 1.28 hours), architecture, timing, and night-to-night variability were similar between groups, the insomnia group reported higher levels of stress and worry, being mainly related to "school". At the intraindividual level, stress and worry predicted shorter sleep duration and earlier wake up times, which, in turn, predicted higher stress the following day. Moreover, higher-than-usual stress predicted higher sleep-time heart rate, with a more consistent effect in adolescents with insomnia. Results were overall consistent after controlling for covariates and several robustness checks.

CONCLUSIONS

There is a bidirectional relationship between daily stress and sleep, with daily stress negatively impacting sleep, which in turn leads to more stress in adolescents with and without insomnia symptoms. Findings also highlight the complexity of insomnia in adolescence, in which the core clinical features (perceived sleep difficulties) and the critical factors (stress/worry) implicated in the pathophysiology of the disorder are not necessarily reflected in objective sleep indicators.

Actigraphy in studies on insomnia: Worth the effort?

In the past decades, actigraphy has emerged as a promising, cost-effective, and easy-to-use tool for ambulatory sleep recording. Polysomnography (PSG) validation studies showed that actigraphic sleep estimates fare relatively well in healthy sleepers. Additionally, round-the-clock actigraphy recording has been used to study circadian rhythms in various populations. To this date, however, there is little evidence that the diagnosis, monitoring, or treatment of insomnia can significantly benefit from actigraphy recordings. Using a case-control design, we therefore critically examined whether mean or within-subject variability of actigraphy sleep estimates or circadian patterns add to the understanding of sleep complaints in insomnia. We acquired actigraphy recordings and sleep diaries of 37 controls and 167 patients with varying degrees of insomnia severity for up to 9 consecutive days in their home environment. Additionally, the participants spent one night in the laboratory, where actigraphy was recorded alongside PSG to check whether sleep, in principle, is well estimated. Despite moderate to strong agreement between actigraphy and PSG sleep scoring in the laboratory, ambulatory actigraphic estimates of average sleep and circadian rhythm variables failed to successfully differentiate patients with insomnia from controls in the home environment. Only total sleep time differed between the groups. Additionally, within-subject variability of sleep efficiency and wake after sleep onset was higher in patients. Insomnia research may therefore benefit from shifting attention from average sleep variables to day-to-day variability or from the development of non-motor home-assessed indicators of sleep quality.

The evolving role of quantitative actigraphy in clinical sleep medicine

Actigraphy has a consolidated role in Insomnia and Circadian Rhythm Sleep-Wake Disorders (CRSWD) and recent studies have highlighted the use of actigraphy for narcolepsy and REM sleep behaviour disorder (RBD). This review aims at summarising the results of studies published over the last decade regarding the use of actigraphy. Thirty-five studies proved eligible, and results were analysed separately for insomnia, narcolepsy and RBD. Actigraphy showed to consistently differentiate insomnia patients from healthy controls. Furthermore, the application of advanced analytical techniques has been shown to provide both unique insights into the physiology of insomnia and sleep misperception and to improve the specificity of actigraphy in detecting wakefulness within sleep periods. Regarding narcolepsy, several studies showed that actigraphy can detect peculiar sleep/wake disruption and the effects of pharmacological treatments. Finally, although the number of studies in RBD patients is still limited, the available evidence indicates a reduced amplitude of the activity pattern, sleep-wake rhythm dysregulation and daytime sleepiness. Therefore, the potential use of these markers as predictors of phenoconversion should be further explored. In conclusion, quantitative actigraphy presents a renewed interest when considering the possibility of using actigraphy in clinical sleep medicine to diagnose, monitor, and follow sleep disorders other than CRSWD.

Theoretical construct into blocks of actigraphic-derived sleep parameters

Actigraphic parameters can provide indication of people's sleep quality during their daily lives. However, there is a need for clear guidelines on the understanding of the different actigraphic parameters. The present study aims to propose a conceptual and theoretical framework for known actigraphic-derived parameters, which is able to describe the alternation between rest and wake phases during the nocturnal sleep, explaining their main characteristics and interrelations that can be replicated in future studies. Forty Sport Sciences students at the University of Milan (20 males; mean age ± SD, 22 ± 3 y) completed the validated Italian version of Morningness-Eveningness Questionnaire (MEQ) and wore an actigraph (Motion Watch 8®, Cambridge Neurotechnology, Cambridge, UK) for seven days. A framework was developed to depict the interactions between the actigraphic parameters and how they objectively describe sleep, according to which the parameters are organized into three different functional blocks related to different aspects of sleep. Correlations analyses were conducted to explore the relationships among the primary actigraphic parameters within and across the functional blocks. The proposed framework is a purely theoretical construct that provides a simple interpretation of known actigraphic parameters guiding researchers and practitioners in the use of these parameters either for research or clinical purposes.

Assessing cognitive behavioral therapy for insomnia in individuals with cannabis use disorder utilizing actigraphy and serum biomarkers: A pilot study

OBJECTIVE/BACKGROUND

This pilot study aims to assess the effect of Cognitive Behavioral Therapy for insomnia (CBTi) in individuals with cannabis use disorder and insomnia. It also aims to investigate the effect of CBTi on levels of serum inflammatory markers in relation to insomnia symptoms.

METHODS/PATIENTS

Individuals with cannabis use disorder and insomnia symptoms were recruited over 18 months. Data collected included demographics, self-reported sleep parameters, and cannabis use. Blood samples were drawn to measure IL-2, IL-6, CRP, and cortisol. Participants completed the Insomnia Severity Index questionnaire (ISI) and the Patient Health Questionnaire-4 (PHQ-4), and they were provided with an actigraphy (wrist) device for 1 week before CBTi and a subsequent week after completing the 4 CBTi sessions.

RESULTS

Nineteen participants were enrolled in the study. The mean ISI score decreased from moderately severe insomnia at baseline to no clinically significant insomnia after CBTi with a sustained decrease at 3- and 6-months follow-up. Actigraphy showed a significant decrease in sleep onset latency (SOL) after CBTi. Three months after CBTi, 80% of participants reported a decrease in their cannabis use. There was also a significant and sustained decrease in mean PHQ-4 scores after CBTi. Although only trending towards significance, the levels of three out of four biomarkers (IL-2, IL-6, CRP) were decreased 6 months after CBTi.

CONCLUSIONS

CBTi is effective as a short- and long-term treatment of insomnia and comorbid anxiety/depression in individuals who regularly use cannabis. A potential added benefit is a reduction in cannabis consumption and inflammatory serum biomarkers.

Technological infrastructure, sleep, and rest-activity patterns in a Kaqchikel Maya community

Sleep duration, quality, and rest-activity pattern-a measure for inferring circadian rhythm-are influenced by multiple factors including access to electricity. Recent findings suggest that the safety and comfort afforded by technology may improve sleep but negatively impact rest-activity stability. According to the circadian entrainment hypothesis, increased access to electric lighting should lead to weaker and less uniform circadian rhythms, measured by stability of rest-activity patterns. Here, we investigate sleep in a Maya community in Guatemala who are in a transitional stage of industrialization. We predicted that (i) sleep will be shorter and less efficient in this population than in industrial settings, and that (ii) rest-activity patterns will be weaker and less stable than in contexts with greater exposure to the natural environment and stronger and more stable than in settings more buffered by technologic infrastructure. Our results were mixed. Compared to more industrialized settings, in our study population sleep was 4.87% less efficient (78.39% vs 83.26%). We found no significant difference in sleep duration. Rest-activity patterns were more uniform and less variable than in industrial settings (interdaily stability = 0.58 vs 0.43; intradaily variability = 0.53 vs 0.60). Our results suggest that industrialization does not inherently reduce characteristics of sleep quality; instead, the safety and comfort afforded by technological development may improve sleep, and an intermediate degree of environmental exposure and technological buffering may support circadian rhythm strength and stability.

Sleep Bruxism Contributes to Motor Activity Increase during Sleep in Apneic and Nonapneic Patients-A Polysomnographic Study

Background: Jaw motor activity (MA) in sleep bruxism (SB) has been demonstrated to accompany lower limb movements. However, it remains unknown whether SB activity coexists with other types of movements and what the possible underlying mechanisms of such temporal coexistence are. In obstructive sleep apnea (OSA), increased movement activity is also reported, including SB activity; however, no studies have compared MA in apneic and nonapneic SB patients. Aim: This cross-sectional study focused on the phenomenon of “big body movements” in patients with either SB or OSA (or both) and intended to identify the primary factors contributing to their appearance, using polysomnography (PSG) recording. Methods: A whole-night videoPSG was carried out in 287 participants, and 124 apneic and 146 nonapneic participants were selected for the study. In both groups, participants were further divided into no SB, moderate SB, and severe SB (SSB) subgroups based on their bruxism episode index (BEI). MA was recorded using a built-in sensor of the central PSG unit located on the participant’s chest during the examination. Results: The presence of SB was related to the higher intensity of MA in both apneic and nonapneic participants, though in general the MA level was higher in apneic participants, with the highest level observed in SSB apneic participants. Conclusions: SB might contribute to MA. The prevalence of SB might be higher in nonapneic patients due to phasic and mixed SB activity, whereas the SB phenotype seems to be less relevant in apneic patients. SB activity is likely to increase MA in non-REM 1 sleep.

Modeling Sleep Quality Depending on Objective Actigraphic Indicators Based on Machine Learning Methods

According to data from the World Health Organization and medical research centers, the frequency and severity of various sleep disorders, including insomnia, are increasing steadily. This dynamic is associated with increased daily stress, anxiety, and depressive disorders. Poor sleep quality affects people's productivity and activity and their perception of quality of life in general. Therefore, predicting and classifying sleep quality is vital to improving the quality and duration of human life. This study offers a model for assessing sleep quality based on the indications of an actigraph, which was used by 22 participants in the experiment for 24 h. Objective indicators of the actigraph include the amount of time spent in bed, sleep duration, number of awakenings, and duration of awakenings. The resulting classification model was evaluated using several machine learning methods and showed a satisfactory accuracy of approximately 80-86%. The results of this study can be used to treat sleep disorders, develop and design new systems to assess and track sleep quality, and improve existing electronic devices and sensors.

Relationships between sleep efficiency and lifestyle evaluated by objective sleep assessment: SLeep Epidemiology Project at University of Tsukuba

Objectively measured sleep efficiency has recently been shown to be associated with health problems. Although several factors have previously been reported to be associated with sleep efficiency, most of these studies were conducted on older or younger adults, and the factors associated with sleep efficiency in healthy workers remain unknown. The aim of this study was to investigate the relationship between sleep efficiency and lifestyle factors using sleep measurement data recorded by an activity meter worn by workers. In total, 693 workers (male, 43.6%; mean age, 42.7 ± 11.3 years) were recruited from five offices in 2017. Sleep was measured over the period of 1 week by actigraphy. Workers' attributes, lifestyle habits, and occupational stress were identified using a questionnaire, and the association of sleep efficiency with lifestyle, occupational stress, and attributes was explored by logistic regression analysis. A logistic regression analysis using attributes and occupational stress as adjustment variables revealed that "longer sleeping hours on weekends than on weekdays" [odds ratios (OR), 0.66; 95% confidence interval (CI), 0.47-0.94], "water ingestion at bedtime" [OR, 2.09; 95% CI, 1.28-3.41], and "smartphone use at bedtime" [OR, 1.90; 95% CI, 1.28-2.83] were associated with decreased sleep efficiency. This study found that lifestyle habits were associated with sleep efficiency among workers. It is necessary to verify whether intervention in these lifestyle habits would contribute to the improvement of sleep efficiency in future studies.

Sleep patterns and potential risk factors for disturbed sleep quality in patients after surgery for infective endocarditis

Background

The current study aimed to investigate the sleep quality of patients after valve replacement surgery due to infective endocarditis and identify risk factors for disturbed sleep post hospitalisation.

Methods

Eighty patients were assessed postoperatively using subjective scale measures, the Pittsburgh sleep quality index (PSQI) and the Epworth sleepiness scale, and an objective measure, actigraphy. Scale measures were assessed approximately 2 weeks and 6 months after surgery. Actigraphy monitoring was performed for 2 consecutive weeks during hospitalisation. Logistic regression was used to identify risk factors for disturbed sleep.

Results

The study population (n = 80) had an average age of 42.8 ± 14.2 years, and 67.5% were male. The median sleep efficiency was 85.3% in week 1 and 86.8% in week 2. The frequency of awakenings was significantly higher in week 1 (20.0 times vs. 19.3 times, p = 0.017). The scale measures showed significant improvement in sleep by 6 months after surgery compared to that during hospitalisation. Multivariable logistic regression analysis suggested that the possible risk factors for disturbed sleep 6 months after surgery included age (OR = 1.479, 95%CI 1.140–1.920) and a few parameters of early postoperative disturbed sleep quality (PSQI: OR = 2.921, 95%CI 1.431–5.963; sleep efficiency: OR = 0.402, 95%CI 0.206–0.783; and average duration of awakenings: OR = 0.006, 95%CI 0.000–0.827).

Conclusions

Disturbed sleep quality was witnessed in postoperative patients during hospitalisation and up to 6 months after surgery. Over time, the patients’ sleep quality improved significantly. Age and a few early postoperative sleep quality variables were risk factors for disturbed sleep 6 months after surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01828-4.

Time Course of Motor Sleep Inertia Dissipation According to Age

Sleep inertia (SI) refers to a complex psychophysiological phenomenon observed after morning awakening that can be described as the gradual recovery of waking-like status after a night of sleep. The time course of SI dissipation in an everyday life condition is little studied. The present study aims to investigate the SI dissipation in motor activity, as a function of age, upon spontaneous morning awakening after a usual night-time sleep. To this end, we performed a retrospective study in a naturalistic setting in a wide life span sample: 382 healthy participants (219 females) from middle childhood (9 years old) to late adulthood (70 years old). Participants were required to wear the actigraph on the non-dominant wrist for at least seven consecutive nights. Results show that SI of motor activity is dissipated in 70 min. Mean motor activity in such a time window was significantly modulated by age: lower age corresponded to higher motor activity.

Associations of actigraphy derived rest activity patterns and circadian phase with clinical symptoms and polysomnographic parameters in chronic insomnia disorders

We explored the associations of actigraphy-derived rest-activity patterns and circadian phase parameters with clinical symptoms and level 1 polysomnography (PSG) results in patients with chronic insomnia to evaluate the clinical implications of actigraphy-derived parameters for PSG interpretation. Seventy-five participants underwent actigraphy assessments and level 1 PSG. Exploratory correlation analyses between parameters derived from actigraphy, PSG, and clinical assessments were performed. First, participants were classified into two groups based on rest-activity pattern variables; group differences were investigated following covariate adjustment. Participants with poorer rest-activity patterns on actigraphy (low inter-day stability and high intra-daily variability) exhibited higher insomnia severity index scores than participants with better rest-activity patterns. No between-group differences in PSG parameters were observed. Second, participants were classified into two groups based on circadian phase variables. Late-phase participants (least active 5-h and most active 10-h onset times) exhibited higher insomnia severity scores, longer sleep and rapid eye movement latency, and lower apnea-hypopnea index than early-phase participants. These associations remained significant even after adjusting for potential covariates. Some actigraphy-derived rest-activity patterns and circadian phase parameters were significantly associated with clinical symptoms and PSG results, suggesting their possible adjunctive role in deriving plans for PSG lights-off time and assessing the possible insomnia pathophysiology.

Insomnia symptom severity and cognitive performance: Moderating role of APOE genotype

INTRODUCTION

We evaluated whether insomnia symptom severity was associated with cognitive function, and whether this relationship was modified by biomarkers associated with Alzheimer's disease risk.

METHODS

We examined insomnia symptoms and neuropsychological performance 3.4 years later in 511 dementia-free Framingham Heart Study participants (62.65 ± 8.7 years, 50.9% male). Additionally, we explored insomnia symptoms combined with self-reported short habitual sleep duration and effect modification by apolipoprotein E (APOE) ε4 allele status.

RESULTS

More severe insomnia symptoms were associated with lower performance on global cognition, and immediate and delayed Logical Memory recall, especially when insomnia symptoms were combined with short sleep duration. The association between insomnia symptoms and poorer memory recall was more pronounced in APOE ε4 allele carriers.

DISCUSSION

Insomnia symptom severity was associated with worse subsequent global cognitive and memory performance, which was especially apparent in APOE ε4 allele carriers, suggesting that poor sleep might be particularly detrimental when the brain is already vulnerable to neurodegeneration.

Characterizing sleep-wake patterns in mothers and children in an agrarian community: results from the Ghana Randomized Air Pollution and Health Study

STUDY OBJECTIVES

Several studies have examined sleep patterns in rural/indigenous communities, however little is known about sleep characteristics in women of reproductive age, and children within these populations. We investigate sleep-wake patterns in mothers and children (ages 3-5 years) leveraging data from the Ghana Randomized Air Pollution and Health Study (GRAPHS).

METHODS

The GRAPHS cohort comprises of rural/agrarian communities in Ghana and collected multiday actigraphy in a subset of women and children to assess objective sleep-wake patterns. Data were scored using the Cole-Kripke and Sadeh algorithms for mothers/children. We report descriptive, baseline characteristics and objective sleep measures, compared by access to electricity/poverty status.

RESULTS

We analyzed data for 58 mothers (mean age 33 ± 6.6) and 64 children (mean age 4 ± 0.4). For mothers, mean bedtime was 9:40 pm ± 56 min, risetime 5:46 am ± 40 min, and total sleep time (TST) was 6.3 h ± 46 min. For children, median bedtime was 8:07 pm (interquartile range [IQR]: 7:50,8:43), risetime 6:09 am (IQR: 5:50,6:37), and mean 24-h TST 10.44 h ± 78 min. Children with access to electricity had a reduced TST compared to those without electricity (p = 0.02). Mean bedtime was later for both mothers (p = 0.05) and children (p = 0.08) classified as poor.

CONCLUSIONS

Mothers in our cohort demonstrated a shorter TST, and earlier bed/risetimes compared to adults in postindustrialized nations. In contrast, children had a higher TST compared to children in postindustrialized nations, also with earlier sleep-onset and offset times. Investigating objective sleep-wake patterns in rural/indigenous communities can highlight important differences in sleep health related to sex, race/ethnicity, and socioeconomic status, and help estimate the impact of industrialization on sleep in developed countries.

A non-parametric model: free analysis of actigraphic recordings of acute insomnia patients

Both parametric and non-parametric approaches to time-series analysis have advantages and drawbacks. Parametric methods, although powerful and widely used, can yield inconsistent results due to the oversimplification of the observed phenomena. They require the setting of arbitrary constants for their creation and refinement, and, although these constants relate to assumptions about the observed systems, it can lead to erroneous results when treating a very complex problem with a sizable list of unknowns. Their non-parametric counterparts, instead, are more widely applicable but present a higher detrimental sensitivity to noise and low density in the data. For the case of approximately periodic phenomena, such as human actigraphic time series, parametric methods are widely used and concepts such as acrophase are key in chronobiology, especially when studying healthy and diseased human populations. In this work, we present a non-parametric method of analysis of actigraphic time series from insomniac patients and healthy age-matched controls. The method is fully data-driven, reproduces previous results in the context of activity offset delay and, crucially, extends the concept of acrophase not only to circadian but also for ultradian spectral components.

Validation of the Chinese version of the Munich Chronotype Questionnaire (MCTQHK) in Hong Kong Chinese youths

Chronotype, referred to as an individual's diurnal preference of timing for rest and activity, can be subjectively measured using the Munich Chronotype Questionnaire (MCTQ). However, the validity of MCTQ has yet to be tested in the youth population. In addition, it remains uncertain if MCTQ is a good measure of chronotype in individuals with insomnia. The current study aimed to validate the Chinese version of MCTQ (MCTQ^HK) in the youth population and to explore the utility of MCTQ^HK in individuals with insomnia. The original MCTQ was translated into Chinese language using the translation-back-translation method. Part one of this study included 988 youths who completed a battery of self-report questionnaires online consisting of the MCTQ^HK and the morningness-eveningness questionnaire (MEQ) for the measures of circadian preference, Insomnia Severity Index (ISI) to assess insomnia symptoms, and Patient Health Questionnaire (PHQ-9) to measure depressive symptoms. Test-retest reliability was examined in 442 participants at one-month follow-up. Of the overall sample, 69 participants were randomly drawn to complete the second part of the study, which included prospective 7-day actigraphy monitoring and a further subset (n = 40) additionally completed a laboratory-based assessment of dim-light melatonin onset (DLMO) as a circadian phase marker. A total of 659 participants with valid responses were finally included in the analyses of the data collected from part one of the study (female = 67.7%; mean age: 20.7 ± 2.02). Results showed that MCTQ parameters, namely the midpoint of sleep on free days (MSF), midpoint of sleep on workdays (MSW), and midpoint of sleep adjusted for sleep debt (MSFsc), were significantly correlated with MEQ score (r = -.514 to -.650, p < .01). Test-retest reliability for MCTQ^HK was good (intraclass correlation = 0.75 to 0.84). Later MSFsc was significantly associated with greater insomnia and depressive symptoms after controlling for age and sex. All MCTQ parameters showed significant correlations with actigraphy-based midpoint of sleep and circadian rhythm parameters, i.e., acrophase and L5 onset (r = .362 to .619, p < .01), as well as DLMO (r = .393 to .517, p < .05). The associations remained significant after controlling for age. MSFsc derived from MCTQ was significantly correlated with MEQ score in both the healthy sleepers and participants with insomnia (as defined by ISI > 14), r = -.600, p < .001 and r = -.543, p < .001, respectively. The present study demonstrated that MCTQ^HK is suitable for assessing chronotype with good reliability and validity in Chinese youths and supported the utility of MCTQ^HK in individuals with insomnia.

Changes in Pre- and Postsurgery for Drug Resistant Epilepsy: Cognition and Sleep

BACKGROUND

Most patients with drug-resistant epilepsy (DRE) have cognitive impairment and sleep disturbance. There was a significant correlation between sleep disorders and cognitive dysfunction. This study performed surgical treatment on patients with DRE and observed seizures, sleep, and cognition in patients with DRE in 6th month after operation to clarify the correlation between sleep and cognition in DRE patients.

METHODS

21 individuals with DRE were recruited to enroll in this trial. Each participant completed epileptic focus resection. Seizure frequency was the principle index; the mean seizure frequency was 1 month before surgery and six months after surgery. Cognitive function was assessed by MMSE, and sleep status was assessed by PSQI and ActiGraph; assessments were performed before and 6 months after surgery.

RESULTS

There were significant differences between conditions on all outcome measures; after 6 months of surgery, compared with before treatment, the monthly average seizure frequency of DRE decreased, which was statistically significant (P < 0.001) compared with that before treatment. The MMSE score of DRE patients was significantly higher than before (P < 0.01), especially the ability of attention, calculation, and recall in MMSE score, which was significantly higher than before operation (respectively, P < 0.001 and P < 0.01). The subjective sleep evaluation index PSQI and objective measurement of sleep latency, total sleep time, and sleep efficiency of patients with DRE by ActiGraph were statistically significant (respectively, P < 0.01) compared with that before treatment. There was a correlation between seizure frequency and MMSE (r = -0.8887, P < 0.0001), PSQI (0.5515, P < 0.01), sleep latency (0.5353, P < 0.05), total sleep time (-0.7814, P < 0.0001), and sleep efficiency (-0.4380, P < 0.05).

CONCLUSIONS

Surgery can effectively reduce the epileptic seizures frequency in patients with DRE and indirectly improve the computational power, attention, recall ability, and sleep status of patients. However, this result did not show a correlation between improved cognitive function and sleep, so the patient's cognitive function may be caused by surgery to improve the frequency of seizures. So, whether the improvement of patients' sleep conditions can also significantly improve the frequency of attacks and cognitive function in patients with DRE needs further exploration.

Relationships Among Sleep Disturbance, Reward System Functioning, Anhedonia, and Depressive Symptoms

Recent models propose reward system dysfunction as a key mediator of the relationship between sleep and depression and anhedonia. This study explored interrelationships among sleep disturbance, depressive symptoms, anhedonia, and reward responsiveness. Two-hundred and sixty undergraduate students completed questionnaires and a daily diary paradigm assessing sleep, reward responsiveness, depression, anhedonia, and positive affect over 1 week. Baseline sleep disturbance was associated with depressive symptoms, anhedonia, and reward responsiveness. Daily diary sleep parameters showed differential associations with anticipatory versus consummatory reward responsiveness and positive affect. Poorer sleep quality, shorter sleep duration, and longer awakening after sleep onset predicted blunted anticipatory and consummatory reward responsiveness, while increased sleep onset latency and lower sleep efficiency predicted only decreased consummatory reward responsiveness. All sleep indices, except sleep onset latency, were associated with positive affect. Findings demonstrate unique associations between disparate sleep disturbance and reward responsiveness elements, highlighting new treatment mechanisms for anhedonia and depression.

How Elderly People's Quality of Life Relates to Their Sleep Quality and Sleep-Related Beliefs

OBJECTIVE/BACKGROUND

Quality of life (QoL) is a broad multidimensional construct, which can be influenced by several factors across the lifespan, including sleep quality. The aim of this study was to examine the association between QoL (and its specific domains), objective and self-reported sleep quality, and subjective sleep-related factors (i.e., dysfunctional beliefs and attitudes about sleep, and metacognitive beliefs about sleeping difficulties) in healthy elderly people.

PARTICIPANTS

Fifty healthy older adults (mean age = 70.40 years, SD = 7.43) participated in the study.

METHODS

QoL was assessed using the World Health Organization's Quality of Life Assessment, BREF version (WHOQOL-BREF). Self-reported sleep quality and efficiency were measured with the Pittsburgh Sleep Quality Index (PSQI) and sleep diary. Dysfunctional beliefs and attitudes about sleep (DBAS), and metacognitive beliefs about sleeping difficulties (MCQ-I) (subjective sleep-related factors) were assessed with self-report questionnaires. Objective sleep quality and efficiency were measured using actigraphy over 7 days.

RESULTS

Regression analyses showed that self-reported sleep efficiency and dysfunctional beliefs and attitudes about sleep explained 24% of the variance in global QoL. Dysfunctional beliefs and attitudes about sleep were the only significant predictor of QoL in the environmental domain.

CONCLUSIONS

Taken together, these findings underscore the influence of sleep-related factors, and particularly dysfunctional beliefs and attitudes about sleep, along with sleep efficiency, on the perception of QoL in healthy older adults. These factors need to be considered in efforts to sustain QoL, in late adulthood at least.

Influence of sleep fragmentation and fatigue on turnover of female nurses working rotating shifts

AIMS AND OBJECTIVES

To investigate whether the sleep quality and fatigue of female nurses working rotating shifts could be used to predict future turnover status.

BACKGROUND

Female nurses working rotating shifts often suffer from sleep problems and fatigue, and the turnover rates of nurses are generally higher than those of other hospital personnel.

DESIGN

A prospective study.

METHODS

We recruited a total of 198 female nurses working rotating shifts from December 2017 to March 2019. The nurses completed the Checklist Individual Strength (CIS) scale and wore an actigraph for seven consecutive days in order to collect their sleep parameters. Their turnover status was tracked until 31 May 2021 at which time 55 participants (27.8%) had resigned. The Cox proportional hazard model was used to analyse the factors influencing turnover. In addition, the study adhered to the STROBE checklist.

RESULTS

The results revealed significant differences between the nurses in the still-working group and the resigned group in terms of the sleep quality parameters sleep efficiency (SE) and wake after sleep onset (WASO) as well as CIS scores. WASO was significantly correlated with intensity of fatigue, and fatigue was common among all of the nurses working rotating shifts. As time progressed, the sleep quality parameter WASO and CIS scores could be used to predict turnover status after 2.4 years.

CONCLUSION

The results of this study indicated more sleep fragmentation and poor sleep efficiency in the resigned group. Sleep fragmentation was highly correlated with fatigue, and sleep fragmentation and fatigue could be used to predict turnover status.

RELEVANCE TO CLINICAL PRACTICE

We suggest that relevant hospital management pay more attention to the sleep conditions and fatigue of female nurses working rotating shifts when arranging personnel and schedules and offer them more understanding.

Detailed analysis and comparison of different activity metrics

Actigraphic measurements are an important part of research in different disciplines, yet the procedure of determining activity values is unexpectedly not standardized in the literature. Although the measured raw acceleration signal can be diversely processed, and then the activity values can be calculated by different activity calculation methods, the documentations of them are generally incomplete or vary by manufacturer. These numerous activity metrics may require different types of preprocessing of the acceleration signal. For example, digital filtering of the acceleration signals can have various parameters; moreover, both the filter and the activity metrics can also be applied per axis or on the magnitudes of the acceleration vector. Level crossing-based activity metrics also depend on threshold level values, yet the determination of their exact values is unclear as well. Due to the serious inconsistency of determining activity values, we created a detailed and comprehensive comparison of the different available activity calculation procedures because, up to the present, it was lacking in the literature. We assessed the different methods by analysing the triaxial acceleration signals measured during a 10-day movement of 42 subjects. We calculated 148 different activity signals for each subject’s movement using the combinations of various types of preprocessing and 7 different activity metrics applied on both axial and magnitude data. We determined the strength of the linear relationship between the metrics by correlation analysis, while we also examined the effects of the preprocessing steps. Moreover, we established that the standard deviation of the data series can be used as an appropriate, adaptive and generalized threshold level for the level intersection-based metrics. On the basis of these results, our work also serves as a general guide on how to proceed if one wants to determine activity from the raw acceleration data. All of the analysed raw acceleration signals are also publicly available.

Objective Assessment of Sleep Patterns among Night-Shift Workers: A Scoping Review

In this scoping review of the literature, we identified the types and the parameters of objective measurements to assess sleep patterns among night-shift workers. We conducted a literature search using electronic databases for studies published from 1991 to 2020 and charted and summarized key information. We included 32 studies in the review. Polysomnography was used in 6 studies and wearable sleep detection devices were utilized in 26 studies. The duration of sleep assessment using the wearable devices ranged from 1 day to ≥4 weeks, and more than half of the studies collected data for >2 weeks. The majority of the studies used subjective questionnaires, such as the Karolinska Sleepiness Scale, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index, in addition to objective sleep measurements. Total sleep time was the most common parameter, followed by sleep efficiency, sleep onset latency, and time or frequency of being awake. As the utilization of wearable devices to assess the sleep patterns of night-shift workers is expected to increase, further evaluation of device accuracy and precision, optimal data collection period, and key parameters is warranted.

Work e-mail after hours and off-job duration and their association with psychological detachment, actigraphic sleep, and saliva cortisol: A 1-month observational study for information technology employees

Objective

A sufficient duration of time off after work is necessary to ensure workers’ health. Better quality of off‐job time can also facilitate recovery from fatigue, but its quantitative influence is largely unknown. We aimed to examine how off‐job time quality (as measured by the frequency of emailing after work), and off‐job duration is associated with psychological detachment, actigraphic sleep, and saliva cortisol using a 1‐month observational study.

Methods

The participants were 58 daytime employees working at an information technology company. Sleep actigraphy and saliva cortisol as well as self‐reported outcomes were repeatedly measured for 1 month. Two‐way (work e‐mail frequency × off‐job time) multilevel mixed‐effects linear regression analyses were performed in both continuous and categorical variables.

Results

The frequency of work e‐mailing after hours was significantly associated with self‐reported outcomes and actigraphic sleep quality, while a significant association was not found in cortisol awakening responses and actigraphic sleep duration. A significantly larger cortisol response after awakening was found in shorter, rather than longer, durations of off‐job time. Self‐reported detachment, rumination and carry‐over fatigue showed significant interactions between work e‐mail and off‐job time, suggesting that worse outcomes were found in a higher frequency of work e‐mail even when employees had longer amounts of off‐job time.

Conclusion

Our findings suggest that ensuring the quality and duration of off‐job time is beneficial for recovery from work with sufficient sleep. Specifically, the frequency of e‐mailing after work should be minimized to make recovery complete.

Association of accelerometer-derived sleep measures with lifetime psychiatric diagnoses: A cross-sectional study of 89,205 participants from the UK Biobank

BACKGROUND

Sleep problems are both symptoms of and modifiable risk factors for many psychiatric disorders. Wrist-worn accelerometers enable objective measurement of sleep at scale. Here, we aimed to examine the association of accelerometer-derived sleep measures with psychiatric diagnoses and polygenic risk scores in a large community-based cohort.

METHODS AND FINDINGS

In this post hoc cross-sectional analysis of the UK Biobank cohort, 10 interpretable sleep measures-bedtime, wake-up time, sleep duration, wake after sleep onset, sleep efficiency, number of awakenings, duration of longest sleep bout, number of naps, and variability in bedtime and sleep duration-were derived from 7-day accelerometry recordings across 89,205 participants (aged 43 to 79, 56% female, 97% self-reported white) taken between 2013 and 2015. These measures were examined for association with lifetime inpatient diagnoses of major depressive disorder, anxiety disorders, bipolar disorder/mania, and schizophrenia spectrum disorders from any time before the date of accelerometry, as well as polygenic risk scores for major depression, bipolar disorder, and schizophrenia. Covariates consisted of age and season at the time of the accelerometry recording, sex, Townsend deprivation index (an indicator of socioeconomic status), and the top 10 genotype principal components. We found that sleep pattern differences were ubiquitous across diagnoses: each diagnosis was associated with a median of 8.5 of the 10 accelerometer-derived sleep measures, with measures of sleep quality (for instance, sleep efficiency) generally more affected than mere sleep duration. Effect sizes were generally small: for instance, the largest magnitude effect size across the 4 diagnoses was β = -0.11 (95% confidence interval -0.13 to -0.10, p = 3 × 10-56, FDR = 6 × 10-55) for the association between lifetime inpatient major depressive disorder diagnosis and sleep efficiency. Associations largely replicated across ancestries and sexes, and accelerometry-derived measures were concordant with self-reported sleep properties. Limitations include the use of accelerometer-based sleep measurement and the time lag between psychiatric diagnoses and accelerometry.

CONCLUSIONS

In this study, we observed that sleep pattern differences are a transdiagnostic feature of individuals with lifetime mental illness, suggesting that they should be considered regardless of diagnosis. Accelerometry provides a scalable way to objectively measure sleep properties in psychiatric clinical research and practice, even across tens of thousands of individuals.

Strategies for controlling sleep-related intrusive thoughts, and subjective and objective sleep quality: how self-reported poor and good sleepers differ

OBJECTIVES

Along with changes in subjective and objective sleep patterns, metacognitive control of intrusive and unwanted thoughts at bedtime has been shown to significantly influence sleep quality. The present study examined individual differences between self-reported poor and good sleepers' thought control strategies, as well as their subjective and objective sleep quality, considering adults in a broad range of ages.

METHOD

The study involved 147 individuals aged 18-79 years, divided into self-reported poor and good sleepers using the Pittsburgh Sleep Quality Index (PSQI). Participants' thought control strategies were assessed using the Thought Control Questionnaire for Insomnia - Revised (TCQI-r). Subjective sleep parameters were recorded in a sleep diary, and objective sleep parameters were measured over 7 days using actigraphy.

RESULTS

Self-reported poor sleepers employed aggressive suppression, reappraisal and worry strategies more than self-reported good sleepers. On logistic regression, the use of reappraisal and worry strategies distinguished between poor and good sleepers, while age did not. Self-reported poor sleepers objectively had a much longer sleep onset latency, a shorter total sleeping time, and a lower sleep efficiency, as well as subjectively longer times awake again after sleep onset, and a lower sleep efficiency than self-reported good sleepers.

CONCLUSION

Together with some subjective and objective sleep parameters, the use of certain thought control strategies (reappraisal and worry, in particular) seems to be one of the crucial aspects accounting for individual differences between self-reported poor and good sleepers.

Correlates of poor sleep based upon wrist actigraphy data in bipolar disorder

BACKGROUND

Wrist-worn actigraphy can objectively measure sleep, and has advantages over self-report, particularly for people with Bipolar Disorder (BD) for whom self-reports might be influenced by affect. Clinically useful data reduction approaches are needed to explore these complex data.

METHODS

We created a composite score of sleep metrics in BD based on 51 BD and 80 healthy comparison (HC) participants. Subjects wore an actigraph for up to 14 consecutive 24-h periods, and we assessed total sleep time (TST), wake after sleep onset (WASO), percent sleep (PS), and number of awakenings (NA). We focused on participants who had at least 5 nights of actigraphy data. We computed z-scores for within-person means of sleep measures for BD subjects versus HCs, which were averaged to create a composite measure. We correlated this composite with participant characteristics, and used LASSO regression to identify sleep measures best explaining variability in identified correlates.

RESULTS

Sleep measures and the composite did not differ between BDs and HCs; however, there was considerable variability in z-scores among those with BD. In BDs, the composite score was higher in women (t₍₄₉₎ = 2.28, p = 0.027) and those who were employed (t₍₃₄₎ = 2.34, p = 0.025), and positively correlated with medication load (r = 0.41, p = 0.003) while negatively correlated with Young Mania Rating Scale (YMRS; r = -0.35, p = 0.030). In LASSO regression, TST and NA best explained medication load while PS best explained employment and YMRS.

CONCLUSION

While a composite score of sleep metrics may provide useful information about sleep quality globally, our findings suggest that selection of theory-driven sleep measures may be more clinically meaningful.

Insomnia Disorders: Nosology and Classification Past, Present, and Future

Insomnia is the most common sleep disorder in the adult population. However, the definition of insomnia disorder has varied across major classification systems and changed over time. In the present study, the investigators traced the evolution of insomnia disorder across classification systems, contemplated the empirical basis for its current definitions, and surveyed ongoing research efforts that may clarify insomnia nosology in the future. Three major classification systems for insomnia are the International Classification of Sleep Disorders, the International Classification of Diseases, and DSM. Despite their divergent origins, these classification systems have converged to nearly identical contemporary insomnia definitions. Over time, the emphasis in classification approaches has shifted from symptomatology to etiology to treatment implications. Additionally, the historical multitude of insomnia subtypes has gradually consolidated into a few core diagnoses, reflecting inadequate evidence with which to support subtyping. Current insomnia definitions include frequency and duration criteria to operationalize these diagnoses, while the diagnostic criterion of nonrestorative sleep has been eliminated (with some controversy). In ongoing research efforts, the quest for insomnia biomarkers has not thus far yielded clinically deployable breakthroughs. Data-driven insomnia subtyping suggests a promising new approach in deriving empirically based subtypes; conversely, the transdiagnostic perspective proposes the elimination of categorical distinctions in favor of finding common processes underlying all psychiatric disorders. The continual evolution of insomnia nosology highlights that much remains to be learned about these conditions; all current diagnostic classification systems are best regarded as "works in progress." Nevertheless, refinement and convergence of classification approaches is essential to standardizing insomnia research, diagnosis, and treatment.

Actigraphy-Based Assessment of Sleep Parameters

Actigraphy, a method for inferring sleep/wake patterns based on movement data gathered using actigraphs, is increasingly used in population-based epidemiologic studies because of its ability to monitor activity in natural settings. Using special software, actigraphic data are analyzed to estimate a range of sleep parameters. To date, despite extensive application of actigraphs in sleep research, published literature specifically detailing the methodology for derivation of sleep parameters is lacking; such information is critical for the appropriate analysis and interpretation of actigraphy data. Reporting of sleep parameters has also been inconsistent across studies, likely reflecting the lack of consensus regarding the definition of sleep onset and offset. In addition, actigraphy data are generally underutilized, with only a fraction of the sleep parameters generated through actigraphy routinely used in current sleep research. The objectives of this paper are to review existing algorithms used to estimate sleep/wake cycles from movement data, demonstrate the rules/methods used for estimating sleep parameters, provide clear technical definitions of the parameters, and suggest potential new measures that reflect intraindividual variability. Utilizing original data collected using Motionlogger Sleep Watch (Ambulatory Monitoring Inc., Ardsley, NY), we detail the methodology and derivation of 29 nocturnal sleep parameters, including those both widely and rarely utilized in research. By improving understanding of the actigraphy process, the information provided in this paper may help: ensure appropriate use and interpretation of sleep parameters in future studies; enable the recalibration of sleep parameters to address specific goals; inform the development of new measures; and increase the breadth of sleep parameters used.

Feasibility of Aerobic Exercise and Tai-Chi Interventions in Advanced Lung Cancer Patients: A Randomized Controlled Trial

BACKGROUND

A majority of lung cancer patients are diagnosed at advanced stages. Although there is considerable evidence of the benefits of aerobic exercise and tai-chi for lung cancer patients, little is known about the comparative effectiveness of the 2 exercise modes in advanced lung cancer patients.

OBJECTIVES

To explore the feasibility and preliminary effects of aerobic exercise and tai-chi interventions on survival and well-being among advanced lung cancer patients.

METHODS

In an assessor-blinded, exploratory randomized controlled trial, 30 advanced lung cancer patients were randomized to an aerobic exercise group, a tai-chi group (both attending 12-week, twice-weekly supervised sessions), or a self-management control group (receiving written exercise guidelines). The primary outcomes focused on feasibility including intervention completion, exercise adherence, and adverse events, while the secondary outcomes addressed preliminary effects and included 1-year survival, cancer symptoms (Pittsburgh Sleep Quality Index, Hospital Anxiety and Depression Score, Brief Fatigue Inventory), quality of life (EORTC QLQ-C30, QLQ-LC13), physical performance (6-minute walk test, up-and-go, sit-to-stand, 1-leg standing), activity levels (actigraph), and circadian rhythms (salivary cortisol).

RESULTS

Intervention feasibility was established with a satisfactory completion rate at post-intervention for the aerobic exercise group (80%) and the tai-chi group (78%). The tai-chi group attained higher adherence than the exercise group in terms of attendance in supervised sessions (89% vs 75% of scheduled classes) and self-practice (225% vs 87% of the prescribed amount). Higher adherence to self-practice in the tai-chi group remained at the 6-month follow-up (81% vs 38% of the prescribed amount). No adverse event as a result of the intervention was reported. Effect-related outcomes did not show statistically significant changes in any group, except an improvement post-intervention in the up-and-go (-2.26, 95% CI: -4.04, -0.48) and sit-to-stand tests (4.52, 95% CI: 2.19, 6.85) in the aerobic exercise group.

CONCLUSIONS

The findings support the feasibility of aerobic exercise and tai-chi interventions in advanced lung cancer patients. A future study with a larger sample from multiple sites is recommended to confirm the comparative effects of the 2 exercise interventions relative to the self-management group and to enhance the generalizability of the findings.

An evidence map of actigraphy studies exploring longitudinal associations between rest-activity rhythms and course and outcome of bipolar disorders

BACKGROUND

Evidence mapping is a structured approach used to synthesize the state-of-the-art in an emerging field of research when systematic reviews or meta-analyses are deemed inappropriate. We employed this strategy to summarise knowledge regarding longitudinal ecological monitoring of rest-activity rhythms (RAR) and disease modifiers, course of illness, treatment response or outcome in bipolar disorders (BD).

STRUCTURE

We had two key aims: (1) to determine the number and type of actigraphy studies of in BD that explored data regarding: outcome over time (e.g. relapse/recurrence according to polarity, or recovery/remission), treatment response or illness trajectories and (2) to examine the range of actigraphy metrics that can be used to estimate disruptions of RAR and describe which individual circadian rhythm or sleep-wake cycle parameters are most consistently associated with outcome over time in BD. The mapping process incorporated four steps: clarifying the project focus, describing boundaries and 'coordinates' for mapping, searching the literature and producing a brief synopsis with summary charts of the key outputs. Twenty-seven independent studies (reported in 29 publications) were eligible for inclusion in the map. Most were small-scale, with the median sample size being 15 per study and median duration of actigraphy being about 7 days (range 1-210). Interestingly, 17 studies comprised wholly or partly of inpatients (63%). The available evidence indicated that a discrete number of RAR metrics are more consistently associated with transition between different phases of BD and/or may be predictive of longitudinal course of illness or treatment response. The metrics that show the most frequent associations represent markers of the amount, timing, or variability of RAR rather than the sleep quality metrics that are frequently targeted in contemporary studies of BD.

CONCLUSIONS

Despite 50 years of research, use of actigraphy to assess RAR in longitudinal studies and examination of these metrics and treatment response, course and outcome of BD is under-investigated. This is in marked contrast to the extensive literature on case-control or cross-sectional studies of actigraphy, especially typical sleep analysis metrics in BD. However, given the encouraging findings on putative RAR markers, we recommend increased study of putative circadian phenotypes of BD.

Sudden Caffeine Withdrawal Triggers Migraine-A Randomized Controlled Trial

Objective: Assessing the effects of caffeine withdrawal on migraine.

Background: The effects of caffeine withdrawal on migraineurs are at large unknown.

Methods: This was a randomized, double-blind, crossover study (NCT03022838), designed to enroll 80 adults with episodic migraine and a daily consumption of 300–800 mg caffeine. Participants substituted their estimated dietary caffeine with either placebo capsules or capsulated caffeine tablets for 5 weeks before switching the comparators for 5 more weeks.

Results: The study was terminated due to low recruitment. Ten subjects with a mean age of 46.3 ± 9.9 years, BMI of 24.9 ± 3.7, and a mean blood pressure of 134/83 ± 17/12 mmHg were enrolled. The average consumption of caffeine per day was 539 ± 196.3 mg. The average monthly headache days and migraine attack frequency at baseline was 11.5 ± 4.9 and 5.2 ± 1.2, respectively. At baseline Pittsburgh Sleep Quality Index was 5.8 ± 2.5 and HIT-6 was 62.8 ± 3.9. There were no differences in these or in parameters from actigraphy during the caffeine period compared with the placebo period. One subject withdrew just after entering the study. In the remaining nine, withdrawal triggered severe migraine attacks in seven, causing one more drop-out, and a typical caffeine withdrawal syndrome in two. Caffeine continuation did not trigger migraines, but one attack occurred in the wake of caffeine reintroduction.

Conclusions: The study failed to answer how caffeine withdrawal affects migraineurs over time, but showed that abrupt withdrawal of caffeine is a potent trigger for migraine attacks.

Patient characteristics associated with sleep disturbance in breast cancer survivors

BACKGROUND

Disturbed sleep is common among breast cancer survivors. Identifying patients at risk for disturbed sleep and its sequelae will aid in improving screening and intervention strategies to improve sleep and cancer-related quality of life (QOL).

METHODS

Women with stages I-III breast cancer undergoing neoadjuvant or adjuvant chemotherapy (N = 415) reported subjectively assessed sleep quality (PSQI) and actigraphy-assessed wake after sleep onset (AAS-WASO), total sleep time (AAS-TST), and sleep efficiency (AAS-SE), sociodemographic, and clinical characteristics and completed questionnaires assessing physical and mental health QOL at study entry and 3, 6, 12, and 15 months later.

RESULTS

Being from a racially/ethnically underserved population was associated with poorer sleep in all indices (p's < .04). Lower income was associated with poorer subjective sleep and greater AAS-WASO (p's < .02). BMI was associated with lower AAS-SE (p < .001). Baseline subjective sleep complaints were positively associated with depression, fatigue, and health-related QOL and cancer-related symptoms across follow-up (p's < 0.05). Baseline AAS-WASO was positively associated with anxiety and negatively associated with physical health-related QOL at the 3-month follow-up (p's < .001). Baseline AAS-WASO and AAS-SE were associated with mental health-related QOL at the 6-month follow-up (p's < .05).

CONCLUSIONS

In keeping with previous health disparity research, racially/ethnically underserved populations, lower household income, and higher BMI were associated with increased risk for disturbed sleep. Sleep disturbance may have long-term effects on multiple aspects of QOL for women undergoing treatment for breast cancer. Results may inform strategies to identify patients at greatest risk for disturbed sleep and its sequelae.

Brain mechanisms of insomnia: new perspectives on causes and consequences

While insomnia is the second most common mental disorder, progress in our understanding of underlying neurobiological mechanisms has been limited. The present review addresses the definition and prevalence of insomnia and explores its subjective and objective characteristics across the 24-hour day. Subsequently, the review extensively addresses how the vulnerability to develop insomnia is affected by genetic variants, early life stress, major life events, and brain structure and function. Further supported by the clear mental health risks conveyed by insomnia, the integrated findings suggest that the vulnerability to develop insomnia could rather be found in brain circuits regulating emotion and arousal than in circuits involved in circadian and homeostatic sleep regulation. Finally, a testable model is presented. The model proposes that in people with a vulnerability to develop insomnia, the locus coeruleus is more sensitive to-or receives more input from-the salience network and related circuits, even during rapid eye movement sleep, when it should normally be sound asleep. This vulnerability may ignite a downward spiral of insufficient overnight adaptation to distress, resulting in accumulating hyperarousal, which, in turn, impedes restful sleep and moreover increases the risk of other mental health adversity. Sensitized brain circuits are likely to be subjectively experienced as "sleeping with one eye open". The proposed model opens up the possibility for novel intervention studies and animal studies, thus accelerating the ignition of a neuroscience of insomnia, which is direly needed for better treatment.

The Effect of Timing and Type of Exercise on the Quality of Sleep in Trained Individuals

Sleep is an extremely important component for overall health and for a well-balanced training program. Recent studies have highlighted the interaction between sleep, recovery, and performance in elite and recreational athletes alike. Exercise has been known to affect the quality of sleep, nevertheless the impact is not well understood in the current research, particularly the effects of exercise timing and intensity on sleep quality. The purpose of this study was to understand if exercise timing and intensity significantly impact sleep quality among recreational exercisers. The participants involved were recreational exercisers who were self-grouped into an AM or PM exercise group. They participated in a seven-day quantitative, quasi-experimental, exploratory study wearing an Actigraph watch. The participant's intensity was also self-grouped into moderate intensity or high intensity based on criteria cut points. Data was analyzed using a factorial ANOVA to examine if there was a significant difference between exercise timing and intensity on sleep quality of the participants. There were no significant differences in sleep quality in either the time group (AM vs PM) or the intensity group (MOD vs VIG) within the four measures of sleep that were looked at throughout this study; total sleep time, sleep onset latency, sleep efficiency % and wake after sleep onset (TST, SOL, SE, and WASO). Results within both, the AM and PM group and the MOD and VIG group, results showed no significant differences. These results conclude that neither exercise intensity or timing had an effect on sleep quality.

Resistance training improves sleep quality, redox balance and inflammatory profile in maintenance hemodialysis patients: a randomized controlled trial

Patients in maintenance hemodialisys (HD) present sleep disorders, increased inflammation, unbalanced redox profiles, and elevated biomarkers representing endothelial dysfunction. Resistance training (RT) has shown to mitigate the loss of muscle mass, strength, improve inflammatory profiles, and endothelial function while decreasing oxidative stress for those in HD. However, the relation between those factors and sleep quality are inadequately described. The aim of this study was to verify the effects of 3 months of RT on sleep quality, redox balance, nitric oxide (NO) bioavailability, inflammation profile, and asymmetric dimethylarginine (ADMA) in patients undergoing HD. Our primary goal was to describe the role of RT on sleep quality. Our secondary goal was to evaluate the effect of RT on NO, metabolism markers, and inflammatory and redox profiles as potential mechanisms to explain RT-induced sleep quality changes. Fifty-five men undergoing maintenance hemodialysis were randomized into either a control (CTL, n = 25) and RT group (RTG; n = 30). Participants in the RT group demonstrated an improvement in sleep pattern, redox, inflammatory profiles, and biomarkers of endothelial function (NO₂^- and ADMA). This group also increased muscle strength (total workload in RT exercises of upper and lower limbs). These findings support that RT may improve the clinical status of HD patients by improving their sleep quality, oxidative and inflammatory parameters.

Sleep quantity and quality and cardiometabolic risk factors in Indigenous Australians

Poor sleep is associated with increased risk of cardiovascular disease (CVD). Indigenous Australians have 1.3 times higher risk of CVD compared to non-indigenous Australians. However, there are limited data describing sleep problems and cardiometabolic risk in this population. This study aimed to investigate sleep quantity and quality in indigenous Australians and assess its association with cardiometabolic risk. Two hundred and forty-five indigenous Australians aged > 18 years were recruited via convenience sampling from communities in the Northern Territory and Queensland. Sleep quantity and quality was assessed subjectively with questionnaires including the Epworth Sleepiness Scale. In a sub-population (n = 46), objective sleep assessment was performed over three nights of actigraphy. Cardiometabolic risk measures included glycated haemoglobin, lipids, anthropometric measurements and sitting blood pressure. Sleep duration measured subjectively and objectively averaged 7.5 ± 2.0 hr/night; however, over one-third of participants (self-report 35%; actigraphy 39%) obtained < 7 hr/night. Overall, more than a third of participants experienced poor-quality sleep, with 27% reporting severe daytime sleepiness (ESS score > 10) and a high number of objectively measured awakenings/night (6 ± 4). Short sleep duration (<6 hr/night) measured both subjectively and objectively was an independent predictor of diastolic (β = 5.37, p = .038) and systolic blood pressure (β = 14.30, p = .048). More objectively measured night-time awakenings were associated with increased glycated haemoglobin levels (β = 0.07, p = .020) and greater sleep fragmentation was associated with lower high-density lipoprotein levels (β = -0.01, p = .025). A large proportion of indigenous Australians experienced short sleep durations and had significant sleep disruption. Poor sleep quantity and quality may contribute to heightened cardiometabolic risk in this population.

Sleep debt induces skeletal muscle injuries in athletes: A promising hypothesis

Sleep is a physiological state and it is fundamental for physical and cognitive recovery of athletes. Due to strenuous training and competitions, athletes may present sleep complaints compromising good quality and quantity of sleep. Studies have related sleep debt to the occurrence of musculoskeletal injuries in athletes, but the mechanisms that can lead to this are not entirely clear. Studies involving animals and humans have shown that poor sleep quality can cause significant changes in hormones and cytokines. Demonstrating that this hormones changes lead to a decrease of testosterone and growth hormone levels and increased cortisol levels, important hormones in the process of protein synthesis and degradation. In athletes, the sport itself is a risk factor of injuries, and sleep debt may result in overtraining syndrome associated with inflammatory markers and ultimately to immune system dysfunction. Thus, we hypothesize that athletes who have sleep debt are more susceptible to musculoskeletal injuries due to increased catabolic pathway signaling, i.e. protein degradation and decreased anabolic pathway signaling, compromising muscle integrity. In this sense, we indicate the relationship between musculoskeletal injuries and sleep debt involving new targets for immunological signaling pathways that start the reduction of the muscle recovery process.