Use of Actigraphy for the Evaluation of Sleep Disorders and Circadian Rhythm Sleep-Wake Disorders: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment

The influence of antidepressants and actigraphy-derived sleep characteristics on pediatric multiple sleep latency testing

STUDY OBJECTIVES

Research evaluating the influence of rapid eye movement suppressing antidepressants (REMS-AD) on multiple sleep latency test (MSLT) results and the value of performing actigraphy prior to this test in children and adolescents is lacking. We examined the impact of REMS-AD and actigraphy parameters on mean sleep latency (MSL) and sleep-onset REM episodes (SOREMs) on MSLT in a pediatric clinical sample.

METHODS

This was a retrospective chart review at a quarternary referral center. We identified 164 MSLTs conducted in patients aged less than 18 years between 2014-2017. Correlations between REMS-AD, self-reported sleep duration, actigraphy parameters and each of the outcomes (MSL and SOREMs) were examined. Regression analyses accounting for clinical characteristics were performed.

RESULTS

Mean age of the sample was 11.9±4.19 years, 62% were female, 28 (17%) were on REMS-AD (48% of whom were able to discontinue these medications prior to MSLT) and mean pediatric daytime sleepiness score was 21.7±6.1. MSL was 11.27±5.77 min and mean number of SOREMs 0.55±1.04. Patients on a REMS-AD at initial assessment had fewer SOREMs compared to those not taking these medications (0.17±0.19 versus 0.62±0.09; p=0.04); no difference was noted in MSL (10.36±1.10 versus 11.47±0.50; p=0.36). Increased time in bed on actigraphy (TIBa) correlated with a longer MSL and fewer SOREMs (r=0.23; p=0.04 and r=0.316; p=0.004 respectively). Following regression analyses, use of REMS-AD continued to remain associated with fewer SOREMs; greater TIBa, but not self-reported sleep duration, was associated with a longer MSL (all p<0.05).

CONCLUSIONS

Clinicians should account for the use of REMS-AD and utilize actigraphy to determine time in bed while interpreting the results of a pediatric MSLT.

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.

Assessing Sleep Architecture With Polysomnography During Posttraumatic Amnesia After Traumatic Brain Injury: A Pilot Study

BACKGROUND

Early-onset sleep disturbance is common following moderate to severe traumatic brain injury (TBI) and often emerges while patients are in posttraumatic amnesia (PTA). However, sleep disruptions during this subacute recovery phase are not well-defined, and research often utilizes indirect measures (actigraphy) that quantify sleep based on activity. This study aims to examine sleep macro-architecture and sleep quality directly with ambulatory polysomnography (PSG) and measure endogenous salivary melatonin levels for patients experiencing PTA following moderate to severe TBI.

METHOD

Participants were recruited from an inpatient TBI rehabilitation unit. Nighttime PSG was administered at the patient's bedside. Two saliva specimens were collected for melatonin testing on a separate evening (24:00 and 06:00 hours) using melatonin hormone profile test kits.

RESULTS

Of 27 patients in whom PSG was recorded, the minimum required monitoring time occurred in n =17 (adherence: 63%) at a median of 37.0 days (quartile 1 [Q1] to quartile 3 [Q3]: 21.5-50.5) postinjury. Median non-rapid eye movement (NREM) and REM sleep proportions were similar to normal estimates. Slow-wave sleep was reduced and absent in 35.3% of patients. Sleep periods appeared fragmented, and median sleep efficiency was reduced (63.4%; Q1-Q3: 55.1-69.2). Median melatonin levels at both timepoints were outside the normal range of values specified for this test (from Australian Clinical Labs).

CONCLUSION

This study reports that ambulatory PSG and salivary melatonin assessment are feasible for patients experiencing PTA and offers new insight into the extent of sleep disturbance. Further research is necessary to understand associations between PTA and sleep disturbance.

Sleep duration and vascular inflammation using hybrid positron emission tomography/magnetic resonance imaging: results from the Multi-Ethnic Study of Atherosclerosis (MESA)

STUDY OBJECTIVES

Short sleep duration (SD) is associated with cardiovascular disease (CVD). We investigated the relationship between objective SD and subclinical atherosclerosis employing hybrid PET/MRI with ¹⁸F-FDG tracer in the MESA cohort.

METHODS

We utilized data from MESA-SLEEP and MESA-PET ancillary studies. SD and sleep fragmentation index (SFI) were assessed using 7-day actigraphy. The primary and secondary outcomes were carotid inflammation, defined using target-to-background ratios (TBR), and measures of carotid wall remodeling (carotid wall thickness [CWT]), summarized by SD category. Multivariate linear regression was performed to assess the association between SD and SFI with the primary/secondary outcomes, adjusting for several covariates including apnea-hypopnea index (AHI), and CVD risk.

RESULTS

Our analytical sample (n=58) was 62% female (mean age 68±8.4 years). Average SD was 5.1±0.9 hours in the short SD group (≤6 hours/night, 31%), and 7.1±0.8 hours in the normal SD group (69%). Prevalence of pathologic vascular inflammation (TBRmax>1.6) was higher in the short SD group (89% vs. 53%, p=0.009). Those with short SD had a higher TBRmax (1.77 vs 1.71), though this was not statistically significant (p=0.39). CWT was positively correlated with SFI even after adjusting for covariates (Beta [SE]=0.073±[0.032], p=0.025).

CONCLUSIONS

Prevalence of pathologic vascular inflammation was higher among those who slept ≤6 hours, and vascular inflammation was higher among those with a SD of ≤6 hours. Interestingly, SFI was positively correlated with CWT even after adjustment for covariates. Our results are hypothesis-generating but suggest that both habitual SD and SFI should be investigated in future studies as potential risk factors for subclinical atherosclerosis.

Validation of the Munich Actimetry Sleep Detection Algorithm for estimating sleep-wake patterns from activity recordings

Periods of sleep and wakefulness can be estimated from wrist-locomotor activity recordings via algorithms that identify periods of relative activity and inactivity. Here, we evaluated the performance of our Munich Actimetry Sleep Detection Algorithm. The Munich Actimetry Sleep Detection Algorithm uses a moving 24-h threshold and correlation procedure estimating relatively consolidated periods of sleep and wake. The Munich Actimetry Sleep Detection Algorithm was validated against sleep logs and polysomnography. Sleep-log validation was performed on two field samples collected over 54 and 34 days (median) in 34 adolescents and 28 young adults. Polysomnographic validation was performed on a clinical sample of 23 individuals undergoing one night of polysomnography. Epoch-by-epoch analyses were conducted and comparisons of sleep measures carried out via Bland-Altman plots and correlations. Compared with sleep logs, the Munich Actimetry Sleep Detection Algorithm classified sleep with a median sensitivity of 80% (interquartile range [IQR] = 75%-86%) and specificity of 91% (87%-92%). Mean onset and offset times were highly correlated (r = .86-.91). Compared with polysomnography, the Munich Actimetry Sleep Detection Algorithm reached a median sensitivity of 92% (85%-100%) but low specificity of 33% (10%-98%), owing to the low frequency of wake episodes in the night-time polysomnographic recordings. The Munich Actimetry Sleep Detection Algorithm overestimated sleep onset (~21 min) and underestimated wake after sleep onset (~26 min), while not performing systematically differently from polysomnography in other sleep parameters. These results demonstrate the validity of the Munich Actimetry Sleep Detection Algorithm in faithfully estimating sleep-wake patterns in field studies. With its good performance across daytime and night-time, it enables analyses of sleep-wake patterns in long recordings performed to assess circadian and sleep regularity and is therefore an excellent objective alternative to sleep logs in field settings.

Objective sleep efficiency but not subjective sleep quality is associated with longitudinal risk of depression in pregnant women: A prospective observational cohort study

BACKGROUND

Sleep disturbances are one of the most frequent chief complaints brought to the healthcare professionals during routine prenatal care visits. Sleep and mood disturbances are often intertwined, and depression in particular is a leading cause of disability and disease burden worldwide with women more likely to be affected than men. However, limited studies have prospectively investigated the association between sleep disturbances and longitudinal risk of depression in pregnant women, with no studies using actigraphy to objectively estimate daytime and nighttime sleep duration and the extent of sleep disruption.

OBJECTIVES

To examine the predictive and longitudinal association of objective actigraphic and subjective sleep disturbances with depressive symptoms in pregnant women.

DESIGN

A prospective observational cohort study.

METHODS

204 1st trimester pregnant women recruited from a university-affiliated hospital provided socio-demographic and health information, wore a wrist actigraph for 7 days, and completed Pittsburgh Sleep Quality Index, Center for Epidemiologic Studies - Depression Scale, and Epworth Sleepiness Scale. Identical data collection procedures were implemented again in the 2nd and 3rd trimester, with each data collection scheduled at least 8 weeks apart. We estimated unadjusted and multivariable adjusted odds ratios and 95% confidence intervals to evaluate various types of sleep disturbances at 1st trimester and risk of depression at follow-ups.

RESULTS

121 (59.3%) 1st trimester women had a sleep efficiency of < 85% by actigraphy, and 92 (45.1%) had Pittsburgh Sleep Quality Index global scores > 5 indicative of poor sleep quality. In multivariable adjusted models, 1st trimester objectively measured sleep efficiency < 85% was associated with 2.71-, 3.87-, and 5.27-fold increased odds having risk of depression at 2nd trimester, 3rd trimester, and both 2nd and 3rd trimesters, respectively.

CONCLUSIONS

Healthy pregnant women experience both objective and subjective sleep disturbances during the early trimester, with a substantial proportion of them also having high depressive symptoms throughout the pregnancy. Objectively assessed poor sleep quality in the 1st trimester, but not self-reported characteristics of disturbed sleep, may play a role in the development of both elevated and persistent high depressive symptoms in pregnancy. Future studies using objective sleep measurements and clinical diagnostic interviews are warranted to examine whether an early intervention aiming at improving sleep may help reduce high depressive symptom risk and lower depression rate in women during pregnancy. Tweetable abstract: Objectively assessed poor sleep efficiency in the 1st trimester predicts both elevated and persistent high depressive symptoms in pregnancy.

Enhancing sleep quality for nursing home residents with dementia: a pragmatic randomized controlled trial of an evidence-based frontline huddling program

Background

Disturbed sleep places older adults at higher risk for frailty, morbidity, and even mortality. Yet, nursing home routines frequently disturb residents’ sleep through use of noise, light, or efforts to reduce incontinence. Nursing home residents with Alzheimer’s disease and or related dementias—almost two-thirds of long-stay nursing home residents—are likely to be particularly affected by sleep disturbance. Addressing these issues, this study protocol implements an evidence-based intervention to improve sleep: a nursing home frontline staff huddling program known as LOCK. The LOCK program is derived from evidence supporting strengths-based learning, systematic observation, relationship-based teamwork, and efficiency.

Methods

This study protocol outlines a NIH Stage III, real-world hybrid efficacy-effectiveness pragmatic trial of the LOCK sleep intervention. Over two phases, in a total of 27 non-VA nursing homes from 3 corporations, the study will (1) refine the LOCK program to focus on sleep for residents with dementia, (2) test the impact of the LOCK sleep intervention for nursing home residents with dementia, and (3) evaluate the intervention’s sustainability. Phase 1 (1 year; n = 3 nursing homes; 1 per corporation) will refine the intervention and train-the-trainer protocol and pilot-tests all study methods. Phase 2 (4 years; n = 24 nursing homes; 8 per corporation) will use the refined intervention to conduct a wedge-design randomized, controlled, clinical trial. Phase 2 results will measure the LOCK sleep intervention’s impact on sleep (primary outcome) and on psychotropic medication use, pain and analgesic medication use, and activities of daily living decline (secondary outcomes). Findings will point to inter-facility variation in the program’s implementation and sustainability.

Discussion

This is the first study to our knowledge that applies a dementia sleep intervention to systematically address known barriers to nursing home quality improvement efforts. This innovative study has future potential to address clinical issues beyond sleep (safety, infection control) and expand to other settings (assisted living, inpatient mental health). The study’s strong team, careful consideration of design challenges, and resulting rigorous, pragmatic approach will ensure success of this promising intervention for nursing home residents with dementia.

Trial registration

NCT04533815, ClinicalTrials.gov, August 20, 2020. 

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02189-8.

Considering cross-cultural differences in sleep duration between Japanese and Canadian university students

Sleep is a fundamental biological process that all humans exhibit, and there is much evidence that people suffer adverse health outcomes from insufficient sleep. Despite this evidence, much research demonstrates significant heterogeneity in the amounts that people sleep across cultures. This suggests that despite serving fundamental biological functions, sleep is also subject to cultural influence. Using self-report and actigraphy data we examined sleep among European Canadian, Asian Canadian, and Japanese university students. Significant cultural differences emerged in terms of various parameters of sleep (e.g. sleep time), and beliefs about sleep (e.g. perceived relation between sleep and health). Despite sleeping significantly less than European Canadians, Japanese participants slept less efficiently, yet reported being less tired and having better health. Moreover, relative to European Canadians, Japanese participants perceived a weaker relation between sleep and physical health, and had a significantly shorter ideal amount of sleep. Asian Canadians’ sleep behaviors and attitudes were largely similar to European Canadians suggesting that people acculturate to local cultural sleep norms.

A meta-analysis of accelerometer sleep outcomes in healthy children based on the Sadeh algorithm: the influence of child and device characteristics

STUDY OBJECTIVES

Children often experience sleep problems, with a negative impact on mood, behavior, cognitive function, and other aspects of mental and physical health. Accelerometers are widely used to assess sleep, but general reference values for healthy children do not yet exist. The aim of this meta-analysis was to determine mean values for wake after sleep onset (WASO), sleep efficiency (SE), total sleep time (TST) and sleep onset latency (SOL), and to determine the effect of child and accelerometer-characteristics.

METHODS

A search included studies with healthy children, 0-18 years, reporting WASO, SE, TST, and/or SOL, calculated with the Sadeh algorithm. Meta-analyses with random effects produced pooled estimate means per outcome. Meta-regression analyses determined the effect of age, sex, placement site and accelerometer type.

RESULTS

Eighty-three studies (9,068 participants) were included. Pooled means were 63 min (95% CI 57 to 69) for WASO, 88% (95% CI 87 to 89) for SE, 477 min (95% CI 464 to 491) for TST and 19 min (95% CI 17 to 22) for SOL. Heterogeneity was high (95%-99%). TST decreased with age and there was an age-effect on SOL. SE differed between wrist and ankle (used in age 0-24 months) placement, and between piezoelectric and MEMS-type accelerometers. No differences were found between boys and girls, although this number of studies was small.

CONCLUSIONS

We found differences in almost all investigated outcomes and heterogeneity was high. Therefore, we advise to use a study-specific control sample until more robust reference values are available. Future research should narrow the methodological heterogeneity and produce larger datasets, needed to establish these reference values.

Associations between migraine attacks and nightly sleep characteristics among adults with episodic migraine: a prospective cohort study

STUDY OBJECTIVES

Given the unknown immediate impact of migraine on nighttime sleep, we prospectively examined whether migraine headaches were associated with subsequent shorter sleep duration, higher fragmentation, and poorer quality in a cohort of 98 adults with episodic migraine.

METHODS

Participants completed twice-daily electronic diaries and wore actigraphs continuously for 6 weeks. We examined whether days with headaches were associated with changes in that night's sleep characteristics compared with headache-free days, using adjusted multivariable linear mixed models with subject-specific intercepts.

RESULTS

Participants were 35 ± 12 years old, 88% women, with an average of five migraine headaches per month. Over 4,406 days, we observed 1,077 headache days, representing 823 discrete headaches. Average nightly objective sleep duration was 7.3 ± 1.2 hr, efficiency 89.5 ± 3.3%, and wake after sleep onset (WASO) 44.8 ± 17.0 min. Objective sleep duration was 7.3 min (95% CI: 1.5, 13.0) longer on nights following a headache day compared with nights on a headache-free day. Objective sleep efficiency, WASO, and reported sleep quality were not significantly different on headache days compared with headache-free days (sleep efficiency: -0.06 min, 95% CI: -0.3, 0.2; WASO 1.5 min, 95% CI: 0.0, 3.0; sleep quality: 1.0, 95% CI: 0.8, 1.3).

CONCLUSIONS

Sleep periods immediately following migraine headaches are not associated with shorter duration, higher disruption, or poorer sleep quality in patients with episodic migraine. These results suggest that clinical evaluation of sleep disturbance in patients with episodic migraine should be approached independently of their migraine status.

Does midlife aging impact women's sleep duration, continuity, and timing?: A longitudinal analysis from the Study of Women's Health Across the Nation

Our study objectives were to evaluate the age-related changes in actigraphy measures of sleep duration, continuity, and timing across 12 years in midlife women as they traversed the menopause, and to take into account factors affecting women's sleep that also change with age. Black, white, and Chinese women were recruited from the Study of Women's Health Across the Nation (SWAN) to participate in an ancillary sleep study on two occasions over 3 years apart and a third assessment 12 years after the first (N = 300, mean ages, 52, 55, and 64 at the three assessments). Women had at least four consecutive nights of actigraphy (95% with 7 nights) and sleep diaries, and self-reported sleep complaints measured at each time point. Partial correlations adjusted for time between assessments across the 12 years were significant and moderate in size (r's = .33-.58). PROC MIXED/GLIMMIX multivariate models showed that sleep duration increased over time; wake after sleep onset (WASO) declined, midpoint of sleep interval increased, and sleep latency and number of sleep complaints did not change between the first and third assessments. Blacks and whites had a greater increase in sleep duration than Chinese. Taken together, the results of this longitudinal study suggest that sleep may not worsen, in general, in midlife women. Perhaps, the expected negative effect of aging in midlife into early old age on sleep is overstated.

Sleep disturbances after pediatric traumatic brain injury: a systematic review of prevalence, risk factors, and association with recovery

STUDY OBJECTIVES

Sleep is vital for brain development and healing after injury, placing children with sleep-wake disturbances (SWD) after traumatic brain injury (TBI) at risk for worse outcomes. We conducted a systematic review to quantify SWD after pediatric TBI including prevalence, phenotypes, and risk factors. We also evaluated interventions for SWD and the association between SWD and other posttraumatic outcomes.

METHODS

Systematic searches were conducted in MEDLINE, PsychINFO, and reference lists for English language articles published from 1999 to 2019 evaluating sleep or fatigue in children hospitalized for mild complicated, moderate, or severe TBI. Two independent reviewers assessed eligibility, extracted data, and assessed risk of bias using the Newcastle-Ottowa Score for observational studies.

RESULTS

Among 966 articles identified in the search, 126 full-text articles were reviewed, and 24 studies were included (11 prospective, 9 cross-sectional, and 4 case studies). Marked heterogeneity was found in study populations, measures defining SWD, and time from injury to evaluation. Studies showed at least 20% of children with TBI had trouble falling or staying asleep, fatigue, daytime sleepiness, and nightmares. SWD are negatively correlated with posttraumatic cognitive, behavioral, and quality of life outcomes. No comparative intervention studies were identified. The risk of bias was moderate-high for all studies often related to lack of validated or objective SWD measures and small sample size. Heterogeneity precluded meta-analyses.

CONCLUSIONS

SWD are important morbidities after pediatric TBI, though current data are limited. SWD have implications for TBI recovery and may represent a modifiable target for improving outcomes after pediatric TBI.

Sleep-Related Problems in Night Shift Nurses: Towards an Individualized Interventional Practice

Rotating shifts (mostly 8- or 12-h) are common among nurses to ensure continuity of care. This scheduling system encompasses several adverse health and performance consequences. One of the most injurious effects of night-time shift work is the deterioration of sleep patterns due to both circadian rhythm disruption and increased sleep homeostatic pressure. Sleep problems lead to secondary effects on other aspects of wellbeing and cognitive functioning, increasing the risk of errors and workplace accidents. A wide range of interventions has been proposed to improve the sleep quality of nurses and promote an increase in attention levels. In recent years, particular attention has been paid to individual and environmental factors mediating the subjective ability to cope with sleep deprivation during the night shift. Given the predictive role of these factors on the negative impact of a night shift, an individualized intervention could represent an effective countermeasure by ensuring suitable management of shift schedules. Therefore, the aims of this mini-review are to: (a) provide an updated overview of the literature on sleep problems in night shift nurses and their adverse consequences; and (b) critically analyze the psychosocial factors that mediate the negative impact of shift work with the ultimate goal of defining an effective countermeasure based on an individualized approach.

Clinical application of mindfulness-oriented meditation in children with ADHD: a preliminary study on sleep and behavioral problems

OBJECTIVE

High incidence of sleep problems in children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD) has been described. Mindfulness meditation has emerged as a novel approach to sleep disturbances and insomnia remediation. This preliminary study tested the efficacy of Mindfulness-Oriented Meditation (MOM) training on sleep quality and behavioral problems in children with ADHD.

DESIGN

Twenty-five children with ADHD aged 7-11 years underwent two programs three times per week for eight-weeks: the MOM training (15 children) and an Active Control Condition (10 children).

MAIN OUTCOME MEASURES

Objective and subjective measures of sleep quality and behavioral measures were collected before and after the programs.

RESULTS

Positive effects on sleep and behavioral measures were found only in the MOM group.

CONCLUSION

Although they are preliminary, our results indicate that MOM training is a promising tool for ameliorating sleep quality and behavioral manifestations in ADHD.

Accuracy of Actigraphy Compared to Concomitant Ambulatory Polysomnography in Narcolepsy and Other Sleep Disorders

Actigraphy provides longitudinal sleep data over multiple nights. It is a less expensive and less cumbersome method for measuring sleep than polysomnography. Studies assessing accuracy of actigraphy compared to ambulatory polysomnography in different sleep-disordered patients are rare. We aimed to compare the concordance between these methods in clinical setting. We included 290 clinical measurements of 281 sleep laboratory patients (mean age 37.9 years, 182 female). Concomitant ambulatory polysomnography and actigraphy were analyzed to determine the agreement in patients with obstructive sleep apnea, narcolepsy, periodic leg movement disorder, hypersomnia, other rarer sleep disorders, or no organic sleep disorder. Bland-Altman plots showed excellent accuracy, but poor precision in single night results between the two methods in the measurement of sleep time, sleep efficiency, and sleep latency. On average, actigraphy tended to overestimate sleep time by a negligible amount, −0.13 min, 95% confidence interval [−5.9, 5.6] min in the whole sample. Overestimation was largest, −12.8 [−25.1, −0.9] min, in patients with obstructive sleep apnea. By contrast, in patients with narcolepsy, actigraphy tended to underestimate sleep time by 24.3 [12.4, 36.1] min. As for sleep efficiency, actigraphy underestimated it by 0.18 [−0.99, 1.35] % and sleep latency by 11.0 [8.5, 13.6] min compared to polysomnography. We conclude that, in measuring sleep time, actigraphy is reasonably reliable and helpful to be used for a week or two to exclude insufficient sleep in patients with the suspicion of narcolepsy. However, the effectiveness of actigraphy in determining sleep seems to decrease in subjects with low sleep efficiencies.

Diagnosing narcolepsy in the active duty military population

PURPOSE

Narcolepsy type I and type II are central hypersomnias characterized by excessive daytime sleepiness and nocturnal sleep disruptions. These rare disorders make the diagnosis complex, as multiple sleep disorders are known to cause false-positive results on testing. There is a high incidence of sleep disorders in the military, and the diagnosis of narcolepsy can have serious career implications. This study looked to assess for the presence of confounding disorders in patients previously diagnosed with narcolepsy.

METHODS

We conducted a retrospective analysis of patients aged 18-65 previously diagnosed with narcolepsy at an outside facility, referred for repeat evaluation at the Wilford Hall Sleep Disorders Center. Previous test results from the time of original diagnosis were reviewed if available and compared with repeat evaluation which included actigraphy, in-laboratory polysomnography, and multiple sleep latency testing.

RESULTS

Of the 23 patients, 2 (9%) retained a diagnosis of narcolepsy after repeat testing. Ten patients (43%) had insufficient sleep syndrome, five (22%) had significant circadian rhythm sleep-wake disorders, and nine (39%) patients were diagnosed with mild obstructive sleep apnea (OSA). Four of the nine patients with OSA (44%) had supine predominant OSA.

CONCLUSION

Diagnostic testing for narcolepsy may be influenced by the presence of comorbid sleep disorders including sleep-disordered breathing, insufficient sleep duration, and circadian misalignment which are common in active military personnel. This study emphasizes the importance of excluding these comorbid diagnoses in this population.

Sleep disorders in rare genetic syndromes: a meta-analysis of prevalence and profile

Background

Sleep disorders are common in people with intellectual disability (ID) and autism, with growing evidence of diverse sleep profiles across ID associated genetic syndromes. Documenting the prevalence and profile of specific sleep disorders in syndromes will quantify syndrome-driven ‘risk’, inform prognosis and enhance understanding of aetiology of sleep disorders.

Method

Following PRISMA guidelines for meta-analysis, we searched Ovid PsycINFO, Ovid MEDLINE, Ovid Embase, Web of Science and PubMed Central with use of syndrome-specific keywords and 60 sleep-related search terms. We screened and extracted papers that reported sleep disorder prevalence data for five or more individuals within a genetic syndrome, and applied quality criteria to produce a quality-effects prevalence model of six types of sleep disorder across nineteen syndromes. Relative risk estimates were calculated for the prevalence of each sleep disorder in each syndrome.

Results

Two hundred and seventy three papers were identified, generating 463 prevalence estimates for Angelman, CHARGE, Cornelia de Lange, Down, fragile X, Prader–Willi, Rett, Smith–Magenis and Williams syndromes, mucopolysaccharidoses (MPS disorders), neurofibromatosis and tuberous sclerosis complex. Prevalence estimates were higher in genetic syndromes than published equivalents for typically developing individuals, with few exceptions. Between-syndrome differences for some disorders were evident; sleep-disordered breathing was most prevalent in MPS disorders (72–77%), while excessive daytime sleepiness was highest in Smith–Magenis syndrome (60%). Conversely, insomnia, which was reported at a higher rate than TD estimates in all syndromes except fragile X, was not associated with specific genetic risk. This suggests insomnia could emerge because of the individual’s environment or associated developmental delay, rather than any specific genetic syndromes.

Limitations

Due to the broad scope of the meta-analysis, only syndromes previously identified as reporting preliminary sleep research were included. Other syndromes may also experience elevated prevalence rates of specific types of sleep disorder. Only English language papers were included.

Conclusions

Differing prevalence rates between types of sleep disorder suggest differing causal mechanisms, such as cranio-facial morphology in Down and Prader–Willi syndromes and the build-up of mucopolysaccharides in MPS disorders. Priorities for clinical assessment and intervention for sleep disorders are discussed.

Video-based sleep detection using ocular signals under the standard conditions of the maintenance of wakefulness test in patients with sleep disorders

OBJECTIVE

Excessive sleepiness is a physiological reaction to sleep deficiency but can also be caused by underlying medical conditions. Detecting sleep is essential in preventing accidents and for medical diagnostics. Polysomnography (PSG) is considered the gold standard for the detection of sleep. More convenient video-based methods for detecting sleepiness have recently emerged.

APPROACH

The possibility of detecting sleep using video-based ocular signals will be assessed using PSG for reference. Ocular signals and EEG are recorded in parallel under the conditions of the maintenance of wakefulness test (MWT) in 30 patients with sleep disorders.

MAIN RESULTS

In detecting sleep, the ocular signal percentage of eyelid closure (PERCLOS) is superior to other ocular signals, resulting in an area under the curve of 0.88. Using a PERCLOS cutoff value of 0.76, sleep is correctly detected with a sensitivity of 89%, a specificity of 76%, the sleep latency is moderately correlated to the reference (rho = 0.66, p < 0.05) and the 95% confidence interval is ±21.1 min.

SIGNIFICANCE

Ocular signals can facilitate the detection of sleep under the conditions of the MWT but sleep detection should not solely rely on ocular signals. If PSG recordings are not practicable or if a signal is needed that responds relatively early in the wake/sleep transition, the use of PERCLOS for the detection of sleep is reasonable.

Effects of Tai Chi or Exercise on Sleep in Older Adults With Insomnia: A Randomized Clinical Trial

IMPORTANCE

Previous studies that have shown tai chi to improve sleep were mainly based on subjective assessments, which might have produced results confounded by self-reporting bias.

OBJECTIVE

To compare the effectiveness of tai chi for improving sleep in older adults with insomnia with conventional exercise and a passive control group using actigraphy-based objective measurements.

DESIGN, SETTING, AND PARTICIPANTS

This randomized, 3-arm, parallel group, assessor-masked clinical trial was conducted at a single research unit in Hong Kong between August 2014 and August 2018. Eligible participants, aged 60 years or older and with chronic insomnia, were randomly allocated into tai chi training, exercise, and control groups.

INTERVENTIONS

12-week tai chi training, 12-week conventional exercise, and no intervention control.

MAIN OUTCOMES AND MEASURES

Primary outcomes were measures taken from actigraphy sleep assessment. Secondary outcomes included remission of insomnia, insomnia treatment response, Pittsburgh Sleep Quality Index score, Insomnia Severity Index score, and self-reported sleep using a 7-day sleep diary. Assessments were performed at baseline, end of the intervention (postintervention), and 24 months after the intervention (follow-up). Data analysis was performed from September 2018 to August 2020.

RESULTS

A total of 320 participants (mean [SD] age, 67.3 [6.8] years; mean [SD] insomnia duration, 124.4 [134.5] months; 256 [80.0%] women) were randomly allocated into control (110 participants), exercise (105 participants), and tai chi (105 participants) groups and included in the data analysis. Compared with the control group, the exercise and tai chi groups showed improved sleep efficiency (exercise vs control: adjusted mean difference, +3.5%; 95% CI, 1.8-5.2; P < .001; tai chi vs control: adjusted mean difference, +3.4%; 95% CI, 1.6-5.1; P < .001) and reductions of wake time after sleep onset (exercise vs control: -17.0 minutes; 95% CI, -24.9 to -9.0; P < .001; tai chi vs control: -13.3 minutes; 95% CI, -21.3 to -5.2; P = .001) and number of awakenings (exercise vs control: -2.8 times; 95% CI, -4.0 to -1.6; P < .001; tai chi vs control: -2.2 times; 95% CI, -3.5 to -1.0; P < .001) as assessed by actigraphy at postintervention; although there were no significant differences between the exercise and tai chi groups. The actigraphy-assessed beneficial effects were maintained in both intervention groups at follow-up.

CONCLUSIONS AND RELEVANCE

Conventional exercise and tai chi improved sleep and the beneficial effects sustained for 24 months, although the absolute improvements in sleep parameters were modest. Improvements in objective sleep parameters were not different between the tai chi and exercise groups, suggesting that tai chi can be an alternative approach for managing insomnia.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02260843.

A method based on cardiopulmonary coupling analysis for sleep quality assessment with FPGA implementation

The relevance of sleep quality examination for clinical diagnosis is increasing with the discovery of new relationships with several diseases and the overall wellness. This assessment is commonly performed by conducting interviews with the subjects, evaluating the self-report and psychological variables. However, this approach has a major constraint since the subject is a poor self-observer of sleep behaviors. To address this issue, a method based on the examination of a physiological signal was developed. Specifically, the single-lead electrocardiogram signal was examined to estimate the cardiopulmonary coupling between the electrocardiogram derived respiration signal and the normal-to-normal sinus interbeat interval series. A one dimensional array was created from the coupling signal and was fed to a convolutional neural network to estimate the sleep quality. The age-related cyclic alternating pattern rate percentages in healthy subjects was considered as the classification reference. An accuracy of 91 % was attained by the developed model, with an area under the receiver operating characteristic curve of 97 %. The performance is in the upper range of the reported performance by the works presented in the state of the art, advocating the relevance of the proposed method. The model was implemented in a small field programmable gate array board. Hence, a home monitoring device was created, composed of a processing unit, a sensing module and a display unit. The device is resilient, easy to self-assemble and operate, and can conceivably be employed for clinical analysis.

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.

Clinical evaluation of the pharmacological impact of ashwagandha root extract on sleep in healthy volunteers and insomnia patients: A double-blind, randomized, parallel-group, placebo-controlled study

ETHNOPHARMACOLOGICAL RELEVANCE

Ashwagandha (Withania somnifera (L.) Dunal.) is long known for its sleep-inducing effects. Ashwagandha can be proposed as an alternative to the recommended present treatments for insomnia. This study aimed to evaluate the pharmacological effect of Ashwagandha root extract on sleep in healthy subjects and also in the subjects having insomnia.

MATERIAL AND METHODS

We performed a randomized, parallel-group, stratified design, placebo-controlled study. A total of 80 eligible participants, 40 in Arm-A (healthy) and 40 in Arm-B (insomnia) were assigned to two groups, either Ashwagandha or placebo and studied for 8-weeks. The assessment was done based on the sleep parameters (Sleep Onset Latency, Total Sleep Time, Wake After Sleep Onset, Total time in bed, and Sleep Efficiency), Pittsburgh Sleep Quality Index and Hamilton Anxiety scale-A questionnaire, mental alertness on rising assessment, and sleep quality questionnaire. Safety and adverse events along with the concomitant medication were also assessed.

RESULTS

In both healthy and insomnia subjects, there was a significant improvement in the sleep parameters in the Ashwagandha root extract supplemented group. The improvement was found more significant in insomnia subjects than healthy subjects. Repeat measure Analysis of variance (ANOVA) confirmed the significant improvement in SOL (p 0.013), HAM-A outcomes (p < 0.05), mental alertness (p 0.01), and sleep quality (p < 0.05) of the insomnia patients. A two-way ANOVA was used to confirm the outcomes that denoted sleep onset latency (p < 0.0001) and sleep efficiency (p < 0.0001) as the most improved parameters, followed by TST (p < 0.002) and WASO(p < 0.040). All these parameters (SOL, TST, WASO, TIB, SE, PSQI, HAM-A, Mental Alertness, and Sleep quality) were also statistically assessed for the significant improvement within the group both for the treatment, and the placebo groups in the healthy and the insomnia datasets. Obtained results suggest statistically significant (p < 0.0001) changes between the baseline values and the end of the study results except for the HAM-A and the mental alertness scoresn the healthy subject group.

CONCLUSION

The present study confirms that Ashwagandha root extract can improve sleep quality and can help in managing insomnia. Ashwagandha root extract was well tolerated by all the participants irrespective of their health condition and age. Additional clinical trials are required to generalize the outcome.

The Sleep of Shift Workers in a Remote Mining Operation: Methodology for a Randomized Control Trial to Determine Evidence-Based Interventions

Shiftwork may adversely impact an individual’s sleep-wake patterns and result in sleep loss (<6 h. following night shift), due to the circadian misalignment and the design of rosters and shifts. Within a mining operation, this sleep loss may have significant consequences due to fatigue, including an increased risk of accidents and chronic health conditions. This study aims to (i) determine the efficacy of an intervention that comprises a sleep education program and biofeedback through a smartphone app on sleep quality, quantity, and alertness (ii) determine the prevalence of risk for a potential sleep disorder, and (iii) quantify and describe the sleep habits and behaviors of shift workers in a remote mining operation. This study consists of a randomized controlled trial whereby eighty-eight shift workers within a remote mining operation are randomized to a control group or one of three different treatment groups that are: (i) a sleep education program, (ii) biofeedback on sleep through a smartphone app, or (iii) a sleep education program and biofeedback on sleep through a smartphone app. This study utilizes wrist-activity monitors, biomathematical modeling, and a survey instrument to obtain data on sleep quantity, quality, and alertness. A variety of statistical methods will determine the prevalence of risk for a potential sleep disorder and associations with body mass index, alcohol, and caffeine consumption. A generalized linear mixed model will examine the dependent sleep variables assessed at baseline and post-intervention for the control group and intervention groups, as well as within and between groups to determine changes. The findings from this study will contribute to the current understanding of sleep and alertness behaviors, and sleep problems and disorders amongst shift workers. Importantly, the results may inform fatigue policy and practice on interventions to manage fatigue risk within the mining industry. This study protocol may have a broader application in other shiftwork industries, including oil and gas, aviation, rail, and healthcare.

Pediatric Insomnia

Insomnia is the most common sleep disorder among all ages; unfortunately, however, child and adolescent insomnia is infrequently addressed. Given the importance of adequate sleep for proper brain development, pediatric populations are particularly vulnerable to the negative effects of insomnia. Therefore, proper clinical assessment and treatment of pediatric insomnia is crucial. This article is the result of a comprehensive literature review and serves as a guide to the disorder and how it presents differently across child development.

The Development and Accuracy of the THIM Wearable Device for Estimating Sleep and Wakefulness

INTRODUCTION

THIM is a new wearable device worn on the finger that can passively monitor sleep and wakefulness overnight using actigraphy. This article showcases the development of the THIM sleep tracking algorithm (Study 1) and the testing of its accuracy against polysomnography (PSG) with an independent sample of good and poor sleepers (Study 2). The accuracy of THIM was compared to two popular wearables, Fitbit and Actiwatch devices.

METHODS

Twenty-five (Study 1) and twenty (Study 2) healthy individuals with good or poor sleep (defined by scores on the Insomnia Severity Index) slept overnight in the sleep laboratory on one night. Participants slept from their typical bedtime to their typical wake up time with simultaneous recording from PSG, THIM, Fitbit and Actiwatch devices.

RESULTS

In both studies, THIM had lower sensitivity (M = 0.89-0.91) compared to the Actiwatch (M = 0.95) and Fitbit devices (M = 0.96-0.98), yet higher specificity (M = 0.59 vs M = 0.32-0.59) in detecting sleep. There were no significant differences between PSG and THIM in either study for sleep onset latency, total sleep time, wake after sleep onset, or sleep efficiency, p > 0.06. Yet, there was high variability in the accuracy of all three actigraphy devices between individuals (evident on Bland-Altman plots) that was unexplained by sleep quality.

DISCUSSION

Together, these studies suggest that THIM is capable of monitoring sleep and wake overnight in good and poor sleepers to a similar degree of accuracy as two of the most popular actigraphy devices available. Future research will examine the accuracy of THIM for monitoring sleep in people with insomnia.

Perceived Stress, Subjective, and Objective Symptoms of Disturbed Sleep in Men and Women with Stable Heart Failure

Objective/Background: Sleep disturbance is prevalent among patients with heart failure (HF) and is associated with increased morbidity and mortality. Stress also affects health and quality of life among patients with cardiovascular disease and likely plays a prominent role in HF. However, little is known about the associations between stress and sleep among HF patients.Participants: One hundred fifty-three stable New York Heart Association (NYHA) Classification I-IV HF patients with at least low symptoms of insomnia (M_age:63.0 ± 12.8, 42% Women).Methods: We examined baseline stress, sleep disturbance, and sleep-related characteristics from a randomized controlled trial of cognitive behavioral therapy for insomnia, including the Perceived Stress Scale, Insomnia Severity Index, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Sleep Disturbance Questionnaire, Dysfunctional Beliefs about Sleep Scale, PROMIS Cognitive Ability, SF-36 Mental Health, and wrist actigraphy. We used Pearson correlations and general linear models to assess stress-sleep associations, including the potential moderating effects of sex and symptom severity (NYHA).Results: There were moderate-to-large correlations between stress and self-reported sleep disturbance, dysfunctional beliefs about sleep, cognitive ability, and mental health (p's < 0.01). High stress was associated with more objectively-measured (i.e., actigraph-assessed) awakenings and sleep fragmentation among women than men (β = - 0.04, p < 0.01; β = - 0.71, p = 0.04). Relationships between stress and objectively-measured sleep did not vary by symptom severity.Conclusions: Perceived stress is related to sleep disturbance among HF patients, and effects may be sex-dependent. Subsequent research should determine the temporal links between sleep and stress, and optimal opportunities for intervention among HF patients.

Sleep Characteristics and Rest-Activity Rhythms Are Associated with Gastrointestinal Symptoms Among Adults with Inflammatory Bowel Disease

BACKGROUND

Sleep disturbance is common in inflammatory bowel disease (IBD) and is associated with poorer quality of life and increased disease activity; however, sleep is a multidimensional process, and little is known about specific sleep characteristics and rest-activity rhythms (RARs) in this population.

AIMS

The purposes were to (1) describe sleep characteristics and RARs; (2) compare sleep characteristics and RARs and GI symptoms by disease activity; and (3) describe associations between sleep characteristics, RARs, and GI symptoms among adults with IBD.

METHODS

We conducted a cross-sectional study of adults with IBD. We measured sleep characteristics and RARs (continuous wrist actigraphy); GI symptoms (PROMIS-GI); and disease activity (physicians' global assessment). We conducted cosinor and nonparametric analyses to compute RAR variables and bivariate analyses to address the aims.

RESULTS

The sample included 37 participants [age M = 38 years (SD = 13.8) and 21 (56.8%) female], of whom 23 (60.6%) were in remission. Sleep efficiency [M = 82.91% (SD 5.35)] and wake after sleep onset (WASO) [M = 42.26 min (SD 18.57)] were not associated with disease activity. Inter-daily stability of the RAR was associated with heartburn/reflux (r = - .491, p = .005) and gas/bloating (r = - .469, p = .008). Intra-daily variability of the RAR was associated with heartburn/reflux (r = .421, p = .018).

CONCLUSIONS

People with IBD may have disrupted RARs, which are associated with GI symptoms. Research is needed to improve understanding of these associations and to develop interventions to improve these characteristics in adults with IBD.

Iron and Insomnia in Autism Spectrum Disorder

Investigators from four major Universities studied the impact of iron supplementation on insomnia symptoms in children with Autism Spectrum Disorder (ASD) and ferritin levels not indicative of iron deficiency anemia.

Effects of sleep-inducing juice on sleep quality and heart rate variability in adults with disturbed sleep

BACKGROUND/OBJECTIVES

Although some juices affect subjective sleep quality, there is a lack of information on the effect of a specific juice on objective sleep quality and heart rate variability (HRV) during sleep; thus the present study investigated whether a blended juice made from natural extracts influenced sleep quality and HRV during sleep in adults with disturbed sleep.

SUBJECTS/METHODS

A randomized, crossover study was conducted on twenty-five adults (15/10, female/male) complaining of difficulty initiating or maintaining nighttime sleep (Pittsburgh sleep quality index [PSQI] ≥ 5). During feeding sessions (FS), subjects received sleep-inducing juice made of natural ingredients (250 mL/trial) twice a day for 8 weeks or non-FS (N-FS) for 8 weeks while maintaining normal activities. Sleep quality and parameters were recorded via wearable actigraph for 7 consecutive days, and PSQI scores were assessed before and after the intervention. HRV was also monitored at rest and during sleep.

RESULTS

After receiving the sleep-inducing juice intervention (FS), PSQI scores were significantly decreased (P < 0.001) and correlated with a significant decline in fatigue severity scale and visual analogue scale levels (P < 0.05; both). HRV indices of vagal activity were significantly improved during FS (P < 0.05), and no significant differences in N-FS were observed. Sleep efficiency and total sleep time increased significantly (P < 0.05) and sleep latency, total counts, sleep fragmentation index, and movement index, decreased significantly (P < 0.05, all 4) during FS, with no significant differences-observed during N-FS.

CONCLUSIONS

This study results demonstrated that an 8-week course of sleep-inducing juice has led to improve sleep quality, suggesting an enhanced cardiac vagal tone during sleep. Thus, it could be a well-tolerated option for adults with disturbed sleep.

Sleep assessment by means of a wrist actigraphy-based algorithm: agreement with polysomnography in an ambulatory study on older adults

The purpose of the present work is to examine, on a clinically diverse population of older adults (N = 46) sleeping at home, the performance of two actigraphy-based sleep tracking algorithms (i.e., Actigraphy-based Sleep algorithm, ACT-S1 and Sadeh's algorithm) compared to manually scored electroencephalography-based PSG (PSG-EEG). ACT-S1 allows for a fully automatic identification of sleep period time (SPT) and within the identified sleep period, the sleep-wake classification. SPT detected by ACT-S1 did not differ statistically from using PSG-EEG (bias = -9.98 min; correlation 0.89). In sleep-wake classification on 30-s epochs within the identified sleep period, the new ACT-S1 presented similar or slightly higher accuracy (83-87%), precision (86-89%) and F1 score (90-92%), significantly higher specificity (39-40%), and significantly lower, but still high, sensitivity (96-97%) compared to Sadeh's algorithm, which achieved 99% sensitivity as the only measure better than ACT-S1's. Total sleep times (TST) estimated with ACT-S1 and Sadeh's algorithm were higher, but still highly correlated to PSG-EEG's TST. Sleep quality metrics of sleep period efficiency and wake-after-sleep-onset computed by ACT-S1 were not significantly different from PSG-EEG, while the same sleep quality metrics derived by Sadeh's algorithm differed significantly from PSG-EEG. Agreement between ACT-S1 and PSG-EEG reached was highest when analyzing the subset of subjects with least disrupted sleep (N = 28). These results provide evidence of promising performance of a full-automation of the sleep tracking procedure with ACT-S1 on older adults. Future longitudinal validations across specific medical conditions are needed. The algorithm's performance may further improve with integrating multi-sensor information.

A systematic review and meta-analysis of wind turbine noise effects on sleep using validated objective and subjective sleep assessments

Little is known about the potential impacts of wind turbine noise (WTN) on sleep. Previous research is limited to cross-sectional studies reporting anecdotal impacts on sleep using inconsistent sleep metrics. This meta-analysis sought to comprehensively review studies evaluating the impact of WTN using widely accepted and validated objective and subjective sleep assessments. Search terms included: "wind farm noise", "wind turbine noise", "wind turbine sound", "wind turbine noise exposure" AND "sleep". Only original articles published in English published after the year 2000 and reporting sleep outcomes in the presence of WTN using polysomnography, actigraphy or psychometrically validated sleep questionnaires were included. Uniform outcomes of the retrieved studies were meta-analysed to examine WTN effects on objective and subjective sleep outcomes. Nine studies were eligible for review and five studies were meta-analysed. Meta-analyses (Hedges' g; 95% confidence interval [CI]) revealed no significant differences in objective sleep onset latency (0.03, 95%  CI -0.34 to 0.41), total sleep time (-0.05, 95%  CI -0.77 to 0.67), sleep efficiency (-0.25, 95%  CI -0.71 to 0.22) or wake after sleep onset (1.25, 95%  CI -2.00 to 4.50) in the presence versus absence of WTN (all p > .05). Subjective sleep estimates were not meta-analysed because measurement outcomes were not sufficiently uniform for comparisons between studies. This systematic review and meta-analysis suggests that WTN does not significantly impact key indicators of objective sleep. Cautious interpretation remains warranted given variable measurement methodologies, WTN interventions, limited sample sizes, and cross-sectional study designs, where cause-and-effect relationships are uncertain. Well-controlled experimental studies using ecologically valid WTN, objective and psychometrically validated sleep assessments are needed to provide conclusive evidence regarding WTN impacts on sleep.

A Systematic Review of Sleep Measurement in Critically Ill Patients

Background: Clinical trialists and clinicians have used a number of sleep quality measures to determine the outcomes of interventions to improve sleep and ameliorate the neurobehavioral consequences of sleep deprivation in critically ill patients, but findings have not always been consistent. To elucidate the source of these consistencies, an important consideration is responsiveness of existing sleep measures. The purpose of an evaluative measure is to describe a construct of interest in a specific population, and to measure the extent of change in the construct over time. This systematic literature review identified measures of sleep quality in critically ill adults hospitalized in the Intensive Care Unit (ICU), and assessed their measurement properties, strengths and weaknesses, clinical usefulness, and responsiveness. We also recommended modifications, including new technology, that may improve clinical usefulness and responsiveness of the measures in research and practice.

Methods: CINAHAL, PubMed/Medline, and Cochrane Library were searched from January 1, 2000 to February 1, 2020 to identify studies that evaluated sleep quality in critically ill patients.

Results: Sixty-two studies using polysomnography (PSG) and other electroencephalogram-based methods, actigraphy, clinician observation, or patient perception using questionnaires were identified and evaluated. Key recommendations are: standard criteria are needed for scoring PSG in ICU patients who often have atypical brain waves; studies are too few, samples sizes too small, and study duration too short for recommendations on electroencephalogram-based measures and actigraphy; use the Sleep Observation Tool for clinician observation of sleep; and use the Richards Campbell Sleep Questionnaire to measure patient perception of sleep.

Conclusions: Measuring the impact of interventions to prevent sleep deprivation requires reliable and valid sleep measures, and investigators have made good progress developing, testing, and applying these measures in the ICU. We recommend future large, multi-site intervention studies that measure multiple dimensions of sleep, and provide additional evidence on instrument reliability, validity, feasibility and responsiveness. We also encourage testing new technologies to augment existing measures to improve their feasibility and accuracy.

Inactograms and objective sleep measures as means to capture subjective sleep problems in patients with a bipolar disorder

BACKGROUND

Sleep problems are common in bipolar disorders (BDs). To objectively characterize these problems in BDs, further methodological development is needed to capture subjective insomnia.

AIM

To test psychometric properties of the Athens Insomnia Scale (AIS), and associations with actigraphy-derived measures, applying modifications in actigraphy data processing to capture features of perturbed sleep in patients with a BD.

METHODS

Seventy-four patients completed the AIS and the Quick Inventory of Depressive Symptomatology, self-report (QIDS-SR-16). Locomotor activity was continuously recorded by wrist actigraphy for ≥10 consecutive days. We computed the sleep onset/offset, the center of daily inactivity (CenDI), as a proxy for chronotype, and the degree of consolidation of daily inactivity (ConDI), as a proxy for sleep-wake rhythm strength.

RESULTS

AIS showed good psychometric properties (Cronbach's alpha = 0.84; test-retest correlation = 0.84, P<.001). Subjective sleep problems correlated moderately with a later sleep phase (CenDI with AIS rho = 0.34, P = .003), lower consolidation (ConDI with AIS rho = -0.22, P = .05; with QIDS-SR-16 rho = -0.27, P = .019), later timing of sleep offset (with AIS rho = 0.49, P = ≤.001, with QIDS-SR-16 rho = 0.36, P = .002), and longer total sleep (with AIS rho = 0.29, P = .012, with QIDS-SR-16 rho = 0.41, P = ≤.001). While AIS was psychometrically more solid, correlations with objective sleep were more consistent across time for QIDS-SR-16.

CONCLUSIONS

AIS and QIDS-SR-16 are suitable for clinical screening of sleep problems among patients with a BD. Subjective insomnia associated with objective measures. For clinical and research purposes, actigraphy and data visualization on inactograms are useful for accurate longitudinal characterization of sleep patterns.

mHealth for pediatric chronic pain: state of the art and future directions

INTRODUCTION

Chronic pain conditions are common among children and engender cascading effects across social, emotional, and behavioral domains for the child and family. Mobile health (mHealth) describes the practice of delivering healthcare via mobile devices and may be an ideal solution to increase access and reach of evidence-based behavioral health interventions.

AREAS COVERED

The aim of this narrative review is to present a state-of-the-art overview of evidence-based mHealth efforts within the field of pediatric chronic pain and consider new and promising directions for study. Given the nascent nature of the field, published mHealth interventions in all stages of development are discussed. Literature was identified through a non-systematic search in PubMed and Google Scholar, and a review of reference lists of papers that were identified as particularly relevant or foundational (within and outside of the chronic pain literature).

EXPERT OPINION

mHealth is a promising interventional modality with early evidence suggesting it is primed to enhance behavioral health delivery and patient outcomes. There are many exciting future directions to be explored including drawing inspiration from digital health technology to generate new ways of thinking about the optimal treatment of pediatric chronic pain.

Suicidal Ideation and Insomnia in Bipolar Disorders: Idéation suicidaire et insomnie dans les troubles bipolaires

OBJECTIVE

Bipolar disorder (BD) confers elevated suicide risk and associates with misaligned circadian rhythm. Real-time monitoring of objectively measured sleep is a novel approach to detect and prevent suicidal behavior. We aimed at understanding associations between subjective insomnia and actigraphy data with severity of suicidal ideation in BDs.

METHODS

This prospective cohort study comprised 76 outpatients with a BD aged 18 to 65 inclusively. Main measures included 10 consecutive days of wrist actigraphy; the Athens Insomnia Scale (AIS); the Montgomery-Åsberg Depression Rating Scale (MADRS); the Quick Inventory of Depressive Symptoms-16, self-rating (QIDS-SR-16); and the Columbia Suicide Severity Rating Scale. Diagnoses, medications, and suicide attempts were obtained from chart review.

RESULTS

Suicidal ideation correlated moderately with subjective insomnia (AIS with QIDS-SR-16 item 12 ρ =0.26, P = 0.03; MADRS item 10 ρ = 0.33, P = 0.003). Graphical sleep patterns showed that suicidal patients were enriched among the most fragmented sleep patterns, and this was confirmed by correlations of suicidal ideation with actigraphy data at 2 visits. Patients with lifetime suicide attempts (n = 8) had more varied objective sleep (a higher standard deviation of center of daily inactivity [0.64 vs. 0.26, P = 0.01], consolidation of daily inactivity [0.18 vs. 0.10, P = <0.001], sleep offset [3.02 hours vs. 1.90 hours, P = <0.001], and total sleep [105 vs. 69 minutes, P = 0.02], and a lower consolidation of daily inactivity [0.65 vs. 0.79, P = 0.03]).

CONCLUSIONS

Subjective insomnia, a nonstigmatized symptom, can complement suicidality screens. Longer follow-ups and larger samples are warranted to understand whether real-time sleep monitoring predicts suicidal ideation in patient subgroups or individually.

Comparison of single-channel EEG, actigraphy, and sleep diary in cognitively normal and mildly impaired older adults

Study Objectives

Multiple methods for monitoring sleep-wake activity have identified sleep disturbances as risk factors for Alzheimer disease (AD). In order to identify the level of agreement between different methods, we compared sleep parameters derived from single-channel EEG (scEEG), actigraphy, and sleep diaries in cognitively normal and mildly impaired older adults.

Methods

Two hundred ninety-three participants were monitored at home for up to six nights with scEEG, actigraphy, and sleep diaries. Total sleep time (TST), sleep efficiency (SE), sleep onset latency (SOL), and wake after sleep onset (WASO) were calculated using each of these methods. In 109 of the 293 participants, the ratio of cerebrospinal fluid concentrations of phosphorylated tau (p-tau) and amyloid-β-42 (Aβ42) was used as a biomarker for AD pathology.

Results

Agreement was highest for TST across instruments, especially in cognitively normal older adults. Overall, scEEG and actigraphy appeared to have greater agreement for multiple sleep parameters than for scEEG and diary or actigraphy and diary. Levels of agreement between scEEG and actigraphy overall decreased in mildly impaired participants and those with biomarker evidence of AD pathology, especially for measurements of TST.

Conclusions

Caution should be exercised when comparing scEEG and actigraphy in individuals with mild cognitive impairment or with AD pathology. Sleep diaries may capture different aspects of sleep compared to scEEG and actigraphy. Additional studies comparing different methods of measuring sleep-wake activity in older adults are necessary to allow for comparison between studies using different methods.

Nurses and Night Shifts: Poor Sleep Quality Exacerbates Psychomotor Performance

In Europe, 40% of health-care employees are involved in shift work. The altered sleep/wake rhythm of night-shift nurses is also associated with deteriorated cognitive efficiency. In this study, we examine the effects of the night shift on psychomotor performance, sleepiness, and tiredness in a large sample of shift-working nurses and evaluated if poor sleep quality, sex, age, or years on the job could impact on a better adaptation to shift work. Eighty-six nurses with 8-h-rapidly-rotating-shifts were evaluated at the end of three shifts (morning/afternoon/night) for sleepiness and tiredness. Sleepiness, as measured by the Karolinska Sleepiness Scale, and tiredness, as measured by the Tiredness Symptoms Scale, were more pronounced after the night shift. These increases were paralleled by lower attentional performance on the psychomotor vigilance task (PVT) after the night shift. While sex, age, and years on the job did not affect PVT performance after the night shift, lower sleep quality (Pittsburgh Sleep Quality, PSQI > 5) was associated with decreased performance. The high prevalence of altered sleep quality showed that nurses, and shift workers in general, are at risk for a poor sleep quality. The evaluation of sleep quality through PSQI could represent a rapid, inexpensive tool to assess health-care workers assigned to rotating night shifts or to evaluate nurses who coped poorly with night-shift work.

Automated feature extraction from population wearable device data identified novel loci associated with sleep and circadian rhythms

Wearable devices have been increasingly used in research to provide continuous physical activity monitoring, but how to effectively extract features remains challenging for researchers. To analyze the generated actigraphy data in large-scale population studies, we developed computationally efficient methods to derive sleep and activity features through a Hidden Markov Model-based sleep/wake identification algorithm, and circadian rhythm features through a Penalized Multi-band Learning approach adapted from machine learning. Unsupervised feature extraction is useful when labeled data are unavailable, especially in large-scale population studies. We applied these two methods to the UK Biobank wearable device data and used the derived sleep and circadian features as phenotypes in genome-wide association studies. We identified 53 genetic loci with p<5×10-8 including genes known to be associated with sleep disorders and circadian rhythms as well as novel loci associated with Body Mass Index, mental diseases and neurological disorders, which suggest shared genetic factors of sleep and circadian rhythms with physical and mental health. Further cross-tissue enrichment analysis highlights the important role of the central nervous system and the shared genetic architecture with metabolism-related traits and the metabolic system. Our study demonstrates the effectiveness of our unsupervised methods for wearable device data when additional training data cannot be easily acquired, and our study further expands the application of wearable devices in population studies and genetic studies to provide novel biological insights.

PSG Validation of minute-to-minute scoring for sleep and wake periods in a consumer wearable device

Background

Actigraphs are wrist-worn devices that record tri-axial accelerometry data used clinically and in research studies. The expense of research-grade actigraphs, however, limit their widespread adoption, especially in clinical settings. Tri-axial accelerometer-based consumer wearable devices have gained worldwide popularity and hold potential for a cost-effective alternative. The lack of independent validation of minute-to-minute accelerometer data with polysomnographic data or even research-grade actigraphs, as well as access to raw data has hindered the utility and acceptance of consumer-grade actigraphs.

Methods

Sleep clinic patients wore a consumer-grade wearable (Huami Arc) on their non-dominant wrist while undergoing an overnight polysomnography (PSG) study. The sample was split into two, 20 in a training group and 21 in a testing group. In addition to the Arc, the testing group also wore a research-grade actigraph (Philips Actiwatch Spectrum). Sleep was scored for each 60-s epoch on both devices using the Cole-Kripke algorithm.

Results

Based on analysis of our training group, Arc and PSG data were aligned best when a threshold of 10 units was used to examine the Arc data. Using this threshold value in our testing group, the Arc has an accuracy of 90.3%±4.3%, sleep sensitivity (or wake specificity) of 95.5%±3.5%, and sleep specificity (wake sensitivity) of 55.6%±22.7%. Compared to PSG, Actiwatch has an accuracy of 88.7%±4.5%, sleep sensitivity of 92.6%±5.2%, and sleep specificity of 60.5%±20.2%, comparable to that observed in the Arc.

Conclusions

An optimized sleep/wake threshold value was identified for a consumer-grade wearable Arc trained by PSG data. By applying this sleep/wake threshold value for Arc generated accelerometer data, when compared to PSG, sleep and wake estimates were adequate and comparable to those generated by a clinical-grade actigraph. As with other actigraphs, sleep specificity plateaus due to limitations in distinguishing wake without movement from sleep. Further studies are needed to evaluate the Arc’s ability to differentiate between sleep and wake using other sources of data available from the Arc, such as high resolution accelerometry and photoplethysmography.

Late and Instable Sleep Phasing is Associated With Irregular Eating Patterns in Eating Disorders

BACKGROUND

Sleep problems are common in eating disorders (EDs).

PURPOSE

We evaluated whether sleep-phasing regularity associates with the regularity of daily eating events.

METHODS

ED patients (n = 29) completed hourly charts of mood and eating occasions for 2 weeks. Locomotor activity was recorded continuously by wrist actigraphy for a minimum of 10 days, and sleep was calculated based on periods of inactivity. We computed the center of daily inactivity (CenDI) as a measure of sleep phasing and consolidation of the daily inactivity (ConDI) as a measure of daily sleep rhythm strength. We assessed interday irregularities in the temporal structure of food intake using the standard deviation (SD) of frequency (IFRQ), timing (ITIM), and interval (IINT) of food intake. A self-evaluation of other characteristics included mood, anxiety, and early trauma.

RESULTS

A later phasing of sleep associated with a lower frequency of eating (eating frequency with the CenDI rho = -0.49, p = .007). The phasing and rhythmic strength of sleep correlated with the degree of eating irregularity (CenDI with ITIM rho = 0.48, p = .008 and with IINT rho = 0.56, p = .002; SD of CenDI with ITIM rho = 0.47, p = .010, and SD of ConDI with IINT rho = 0.37, p = .048). Childhood Trauma Questionnaire showed associations with variation of sleep onset (rho = -0.51, p = .005) and with IFRQ (rho = 0.43, p = .023).

CONCLUSIONS

Late and variable phasing of sleep associated robustly with irregular pattern of eating. Larger data sets are warranted to enable the analysis of diagnostic subgroups, current medication, and current symptomatology and to confirm the likely bidirectional association between eating pattern stability and the timing of sleep.

Fit-for-Purpose Biometric Monitoring Technologies: Leveraging the Laboratory Biomarker Experience

Biometric monitoring technologies (BioMeTs) are becoming increasingly common to aid data collection in clinical trials and practice. The state of BioMeTs, and associated digitally measured biomarkers, is highly reminiscent of the field of laboratory biomarkers 2 decades ago. In this review, we have summarized and leveraged historical perspectives, and lessons learned from laboratory biomarkers as they apply to BioMeTs. Both categories share common features, including goals and roles in biomedical research, definitions, and many elements of the biomarker qualification framework. They can also be classified based on the underlying technology, each with distinct features and performance characteristics, which require bench and human experimentation testing phases. In contrast to laboratory biomarkers, digitally measured biomarkers require prospective data collection for purposes of analytical validation in human subjects, lack well‐established and widely accepted performance characteristics, require human factor testing, and, for many applications, access to raw (sample‐level) data. Novel methods to handle large volumes of data, as well as security and data rights requirements add to the complexity of this emerging field. Our review highlights the need for a common framework with appropriate vocabulary and standardized approaches to evaluate digitally measured biomarkers, including defining performance characteristics and acceptance criteria. Additionally, the need for human factor testing drives early patient engagement during technology development. Finally, use of BioMeTs requires a relatively high degree of technology literacy among both study participants and healthcare professionals. Transparency of data generation and the need for novel analytical and statistical tools creates opportunities for precompetitive collaborations.

Blue-Enriched White Light Improves Performance but Not Subjective Alertness and Circadian Adaptation During Three Consecutive Simulated Night Shifts

Use of blue-enriched light has received increasing interest regarding its activating and performance sustaining effects. However, studies assessing effects of such light during night work are few, and novel strategies for lighting using light emitting diode (LED) technology need to be researched. In a counterbalanced crossover design, we investigated the effects of a standard polychromatic blue-enriched white light (7000 K; ∼200 lx) compared to a warm white light (2500 K), of similar photon density (∼1.6 × 1014 photons/cm2/s), during three consecutive simulated night shifts. A total of 30 healthy participants [10 males, mean age 23.3 (SD = 2.9) years] were included in the study. Dependent variables comprised subjective alertness using the Karolinska Sleepiness Scale, a psychomotor vigilance task (PVT) and a digit symbol substitution test (DSST), all administered at five time points throughout each night shift. We also assessed dim-light melatonin onset (DLMO) before and after the night shifts, as well as participants' opinion of the light conditions. Subjective alertness and performance on the PVT and DSST deteriorated during the night shifts, but 7000 K light was more beneficial for performance, mainly in terms of fewer errors on the PVT, at the end of the first- and second- night shift, compared to 2500 K light. Blue-enriched light only had a minor impact on PVT response times (RTs), as only the fastest 10% of the RTs were significantly improved in 7000 K compared to 2500 K light. In both 7000 and 2500 K light, the DLMO was delayed in those participants with valid assessment of this parameter [n = 20 (69.0%) in 7000 K light, n = 22 (78.6%) in 2500 K light], with a mean of 2:34 (SE = 0:14) and 2:12 (SE = 0:14) hours, respectively, which was not significantly different between the light conditions. Both light conditions were positively rated, although participants found 7000 K to be more suitable for work yet evaluated 2500 K light as more pleasant. The data indicate minor, but beneficial, effects of 7000 K light compared to 2500 K light on performance during night work. Circadian adaptation did not differ significantly between light conditions, though caution should be taken when interpreting these findings due to missing data. Field studies are needed to investigate similar light interventions in real-life settings, to develop recommendations regarding illumination for night workers. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03203538.

The clinical problem of the lethality of insomnia: a new empirical exploration from a clinical trial

Moul DE. The clinical problem of the lethality of insomnia: a new empirical exploration from a clinical trial. J Clin Sleep Med. 2020;16(8):1225–1227.

An exploratory analysis of the association of circadian rhythm dysregulation and insomnia with suicidal ideation over the course of treatment in individuals with depression, insomnia, and suicidal ideation

STUDY OBJECTIVES

Sleep disturbance is significantly associated with suicidal ideation. However, the majority of past research has examined the relationship between insomnia and suicidality. The current exploratory study examined the relationship of circadian rhythm dysregulation (eveningness, seasonality, and rhythmicity) with suicidality.

METHODS

We examined the association of insomnia, eveningness, seasonality, and rhythmicity with suicidal ideation in 103 participants with depression, insomnia, and suicidality within a larger 8-week double-blinded randomized control trial primarily examining whether cautious use of zolpidem extended-release or placebo reduced suicidal ideation. All participants additionally received an open-label selective serotonin reuptake inhibitor. Methodological strengths of the current analyses included consideration of multiple sleep-wake constructs, adjustment for relevant covariates, investigation of relationships over the course of treatment, and use of both self-report measures and objective measurement with actigraphy.

RESULTS

Over the course of treatment, self-reported eveningness and greater insomnia severity were independently correlated with greater suicidal ideation, whereas actigraphic delayed sleep timing was related to suicidal ideation at a trend level. At the end of treatment, those with greater suicidal ideation demonstrated lower actigraphic activity levels. There were no significant relationships between self-reported seasonality and actigraphic measures of sleep disturbance and suicidality.

CONCLUSIONS

Self-reported delays in sleep timing, objectively lower activity levels, and self-reported insomnia severity correlated independently with greater suicidal ideation in those with depression, insomnia, and suicidality. These exploratory findings highlight the need to consider sleep-wake constructs more broadly in those with suicidality in future research studies in order to improve more definitively both assessment and intervention efforts.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Reducing Suicidal Ideation through Insomnia Treatment; URL: https://clinicaltrials.gov/ct2/show/NCT01689909; Identifier: NCT01689909 Rumble ME, McCall MV, Dickson DA, Krystal AD, Rosenquist PB, Benca RM. An exploratory analysis of the association of circadian rhythm dysregulation and insomnia with suicidal ideation over the course of treatment in individuals with depression, insomnia, and suicidal ideation. J Clin Sleep Med. 2020;16(8):XXX-XXX.

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.

Central Disorders of Hypersomnolence

PURPOSE OF REVIEW

This article discusses the central disorders of hypersomnolence, a group of disorders resulting in pathologic daytime sleepiness, particularly narcolepsy type 1 and narcolepsy type 2, idiopathic hypersomnia, and Kleine-Levin syndrome. Disease features, diagnostic testing, epidemiology, pathophysiology, and treatment are reviewed.

RECENT FINDINGS

Increasing evidence implicates autoimmunity in narcolepsy type 1, including a strong association with human leukocyte antigen-DQB1*06:02, association with a polymorphism in the T-cell receptor alpha locus in genome-wide association, and the identification of autoreactive T cells in patients with this type of narcolepsy. In contrast, the cause or causes of narcolepsy type 2 and idiopathic hypersomnia are unknown. Multiple treatment options exist, including two medications approved for the treatment of narcolepsy by the US Food and Drug Administration (FDA) in 2019. These include solriamfetol, a dopamine- and norepinephrine-reuptake inhibitor, and pitolisant, an H3-inverse agonist/antagonist that increases histaminergic neurotransmission.

SUMMARY

The central disorders of hypersomnolence all cause severe sleepiness but can be differentiated based on ancillary symptoms, diagnostic testing, and pathophysiology. It is important that these disorders are identified because multiple treatments are available to improve functioning and quality of life.