SLEEP

McCarthy, Michaela S; Hoffmire, Claire; Brenner, Lisa A; Nazem, Sarra

doi: 10.1093/sleep/zsz094pmid: 31180507

Study ObjectivesSuicide is a top public health priority, and U.S. Veterans are recognized to be at particularly elevated risk. Sleep disturbances are an independent risk factor for suicide; recent empirical data suggest that nocturnal wakefulness may be a key mechanism underlying this association. Given higher rates of sleep disturbances among U.S. Veterans compared with civilians, we examined associations between nocturnal wakefulness and timing of death by suicide in U.S. Veterans and civilians to determine whether temporal suicide patterns differed.MethodsThe American Time Use Survey and the National Violent Death Reporting System were analyzed (2006–2015) to determine whether sleep and temporal suicide patterns differed between age-stratified groups (18–39, 40–64, and ≥65) of U.S. Veterans and civilians. Observed temporal suicide patterns were reported and standardized incidence ratios (SIRs) calculated to compare the percentage of suicides observed with those expected, given the proportion of the population awake, across clock hours.ResultsThe raw proportion of Veteran suicides peaks between the hours of 1000–1200; however, the peak prevalence of suicide after accounting for the population awake is between 0000 and 0300 hr (p < .00001, ϕ = .88). The highest SIR was at midnight; U.S. Veterans were eight times more likely to die by suicide than expected given the population awake (SIR = 8.17; 95% CI = 7.45–8.94).ConclusionsNocturnal wakefulness is associated with increased risk for suicide in U.S. Veterans. Overall patterns of observed suicides by clock hour were similar between U.S. Veterans and civilians. However, Veteran-specific SIRs suggest differences in magnitude of risk by clock hour across age groups. Future research examining female and Post-9/11 U.S. Veterans is warranted.

McWhorter, Ketrell L; Parks, Christine G; D’Aloisio, Aimee A; Rojo-Wissar, Darlynn M; Sandler, Dale P; Jackson, Chandra L

doi: 10.1093/sleep/zsz108pmid: 31260523

Study ObjectivesExposure to traumatic childhood experiences (TCEs) may contribute to poor sleep in adulthood. Previous studies have been limited to mainly investigating physical and sexual abuse and did not consider betrayal trauma, or whether the victim regarded the perpetrator as someone socially close to them, the age group at occurrence, and trauma-related distress/anxiety.MethodsWe used a large cohort of US women, 35–74 years old, enrolled in the Sister Study from 2003 to 2009. Self-reports of specific TCEs occurring before the age of 18 years included sexual, physical, and psychological/emotional trauma; natural disasters; major accidents; and household dysfunction. Participants self-reported average sleep duration (short: <7 hours vs recommended: 7–9 hours), sleep onset latency (SOL) at least 30 vs less than 30 minutes, at least 3 night awakenings once asleep at least 3 times/week (Night awakenings [NA], yes vs no), and napping at least 3 vs less than 3 times/week.ResultsAmong 40 082 women, 55% reported a TCE, with 82% reporting betrayal trauma. Compared to women reporting no TCE, women with any TCE were more likely to report short sleep (prevalence ratio [PR] = 1.08, [95% confidence interval (CI) = 1.04 to 1.11]), longer SOL (1.11, [1.06 to 1.16]), frequent NAs (1.06, [1.00 to 1.11]), and frequent napping (1.05, [0.99 to 1.12]). The relationship between experiencing any TCE and short sleep was stronger for TCEs by a perpetrator considered socially close vs not close (1.12, [1.09 to 1.16]), SOL (1.27, [1.22 to 1.33]), NA (1.20, [1.14 to 1.27]), and napping (1.24, [1.17 to 1.32]).ConclusionsTCEs were associated with poor sleep in women with greater impact when the perpetrator was regarded as close. More research is warranted to better understand pathways between childhood trauma and sleep health in adulthood to develop effective interventions.

Wang, Guanghai; Deng, Yujiao; Jiang, Yanrui; Lin, Qingmin; Dong, Shumei; Song, Yuanjin; Zhu, Lixia; Zhu, Qi; Sun, Wanqi; Zhang, Yunting; Jiang, Fan

doi: 10.1093/sleep/zsz106pmid: 31152540

Alger, Sara E; Brager, Allison J; Capaldi, Vincent F

doi: 10.1093/sleep/zsz097pmid: 31390041

“Why should someone get paid to sleep on the job?” “I don’t have time to nap. I have too much work to do.” “You must be lazy if you take naps.” Despite growing awareness and appreciation of the value of sleep as well as resources, such as books by prominent sleep researchers [1, 2], directed toward general public consumption, there still remains a stigma related to napping. This negative perception is compounded when considering napping during working hours, resulting in frequently heard comments and questions like those above. How can we as sleep scientists, the subject matter experts who appreciate the broad scope of benefits to physical, emotional, and cognitive health conferred by naps, combat the negative optics of workplace napping? We begin by addressing these points of contention. “Why Should Someone Get Paid to Sleep on the Job?” While napping is essential for the health and development of young children, for many people it carries into adulthood as a habitual practice. In the United States, however, most working adults are not able to fit a nap into the day, largely due work demands and employer resistance to change workplace culture. Yet outside the United States, there are culturally different attitudes toward napping. In Spain and Italy, mid-afternoon breaks known as the siesta and riposo, respectively, are scheduled during the workday wherein napping often occurs. To suggest such a revision in business hours for the modern US workplace, however, may be unreasonable. Some Asian countries, such as China and Japan, encourage napping on the job. Japanese practice inemuri, sleeping or daydreaming during work, which is viewed as a sign of dedication to work to the point of exhaustion. Japanese businessmen also frequent capsule hotels containing sleep pods in order to reap the recuperative value of sleep during multi-day business negotiations. In the United States, coffee breaks and time spent browsing social media occur in part to boost and re-direct mental focus. What if more employers replaced coffee breaks with scheduled naps? Dr. James B. Maas, who coined the term “power nap,” encourages prioritizing sleep whenever possible, including implementing office napping policies [2]. Employees already seek out covert naps, and internet tips for “sneaking in a nap at work” reveal unsanitary (restroom) and uncomfortable (car) locations as top sites for napping. If employers embraced workplace napping, this option could produce a comparatively more marked and sustained increase in productivity. As many are sleep restricted during the work week, napping may confer performance advantages similar to data reported in the January 2019 issue of SLEEP [3]. Perhaps a better question may be “What is the cost of working fatigued?” According to a fatigue cost estimator from the National Safety Council and Brigham and Women’s Sleep Matters Initiative, health-related cost of lost productivity is $136 billion a year. Further, a reported 70% of Americans regularly experience insufficient sleep. Sleep loss, especially in the presence of underlying sleep disorders, results in reduced workplace productivity and increased absenteeism, health care expenditures, workplace accidents and injuries, and motor vehicle accidents during commutes. Thus, it may be costing employers more in the long-term not to allow workers to increase total daily sleep time and alertness with a brief nap during working hours than to prevent napping when needed. “I Don’t Have Time to Nap. I Have Too Much Work.” During an average work afternoon, a disproportion of the circadian alerting signal to the rising homeostatic sleep pressure occurs, resulting in increased sleepiness and reduced alertness. These factors, along with other impacted cognitive and emotional performance metrics, result in decreased productivity. There is a wealth of evidence that brief daytime naps of 10–20 minutes decrease subjective sleepiness, increase objective alertness, and improve cognitive performance (for review [4, 5]). Daytime napping facilitates creative problem solving and logical reasoning, boosts the capacity for future learning, and consolidates memories (for review [6]). These benefits are not restricted to those experiencing sleep deprivation. Even in well-rested individuals, napping can enhance alertness, performance, and productivity for several hours [4]. Daytime naps also allow for the regulation of emotions [7], relieve stress, and strengthen immune system function, reducing levels of the stress hormone norepinephrine and normalizing levels of interleukin-6 an immune-regulating molecule [8]. Taken together, allowing time to nap during the workday and reap the collective benefits will result in greater productivity and quality output rather than simply pushing through the fatigue, producing sub-standard work. “You Must be Lazy if You Take Naps.” This statement reflects the most damaging and pervasive stigma placed upon napping. Sleep deprivation, in some populations, is still considered a point of pride and a reflection of toughness. However, this argument is based largely in ignorance and companies are beginning a movement to counteract it. Along with recommendations to sleep 7–9 hours at night, daytime naps are being integrated into workplace culture in the world’s largest grossing tech, consulting, media, and retail companies: Google, Uber, Nike, Cisco, Zappos, Huffington Post, PricewaterhouseCoopers, Proctor & Gamble, and Ben & Jerry’s. Not only do these companies encourage workplace naps, but they provide accommodations, such as rooms secluded for the purpose of napping, often equipped with nap pods or beds. Even government agencies focused on fatigue countermeasures (e.g. NASA and the Federal Aviation Administration) provide napping pods in which employees can rest and restore cognitive and emotional resources. The challenge is to continue the spread of information regarding the wealth of benefits of napping to combat the numerous physical, mental, and financial consequences of fatigue. The long-term plan is to normalize and implement scheduled napping during working hours. One of the first steps in this process is to gather empirical evidence demonstrating the relative increase to workplace productivity with a brief nap compared to soldiering on without it. There exists a plethora of laboratory-based napping experiments. However, there is a dearth of applied research in the workplace examining the impact of a napping intervention on occupationally relevant performance measures. Building and disseminating this evidence will push us closer to a society that values napping and works to remove the stigma of taking that mid-day snooze. Disclaimer This material has been reviewed by the Walter Reed Army Institute of Research, and there is no objection to its presentation and/or publication. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the position of the Department of the Army or the Department of Defense. Funding None declared. Conflict of interest statement. None declared. Acknowledgments The authors thank Dr. Tina Burke for her suggestions and amendments. References 1. Mednick SC , et al. Take a Nap!: Change Your Life . New York, NY : Workman Publishing Company ; 2006 . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 2. Maas JB , et al. Power Sleep: The Revolutionary Program that Prepares Your Mind for Peak Performance . New York : Villard . 1998 . Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 3. Cousins JN , et al. A split-sleep schedule rescues short-term topographical memory after multiple nights of sleep restriction . Sleep . 2019 ; 42 ( 4 ). doi. 10.1093/sleep/zsz018 Google Scholar OpenURL Placeholder Text WorldCat Crossref 4. Ficca G , et al. Naps, cognition and performance . Sleep Med Rev. 2010 ; 14 ( 4 ): 249 – 258 . Google Scholar Crossref Search ADS PubMed WorldCat 5. Hilditch CJ , et al. A review of short naps and sleep inertia: do naps of 30 min or less really avoid sleep inertia and slow-wave sleep? Sleep Med. 2017 ; 32 : 176 – 190 . Google Scholar Crossref Search ADS PubMed WorldCat 6. Mantua J , et al. Exploring the nap paradox: are mid-day sleep bouts a friend or foe? Sleep Med. 2017 ; 37 : 88 – 97 . Google Scholar Crossref Search ADS PubMed WorldCat 7. Gujar N , et al. A role for REM sleep in recalibrating the sensitivity of the human brain to specific emotions . Cereb Cortex. 2011 ; 21 ( 1 ): 115 – 123 . Google Scholar Crossref Search ADS PubMed WorldCat 8. Faraut B , et al. Napping reverses the salivary interleukin-6 and urinary norepinephrine changes induced by sleep restriction . J Clin Endocrinol Metab. 2015 ; 100 ( 3 ): E416 – E426 . Google Scholar Crossref Search ADS PubMed WorldCat Published by Oxford University Press on behalf of Sleep Research Society (SRS) 2019. This work is written by (a) US Government employee(s) and is in the public domain in the US. Published by Oxford University Press on behalf of Sleep Research Society (SRS) 2019.

Parmar, Arpita; Yeh, E Ann; Korczak, Daphne J; Weiss, Shelly K; Lu, Zihang; Zweerink, Allison; Toulany, Alene; Murray, Brian J; Narang, Indra

doi: 10.1093/sleep/zsz111pmid: 31070768

Study ObjectivesTo evaluate the association between depressive symptoms, sleep patterns (duration and quality), excessive daytime sleepiness (EDS), and physical activity (PA) in adolescents with narcolepsy.MethodsThis cross-sectional study included adolescents (ages 10–18 years) with narcolepsy attending a tertiary care facility (The Hospital for Sick Children, Toronto, Canada). Adolescents with narcolepsy completed questionnaires evaluating depressive symptoms (Children’s Depression Inventory-2nd edition [CDI-2]), sleep quality (Pittsburgh Sleep Quality Index), EDS (Epworth Sleepiness Scale), and PA (Godin Leisure-Time Exercise Questionnaire). Wrist-based actigraphy was worn by adolescents for 1 week to measure total sleep time (over 24 hr) and sleep efficiency percentage.ResultsThirty adolescents with narcolepsy (mean age = 13.8 ± 2.2 years, 76.7% male) participated. In this cohort of adolescents with narcolepsy, 23.3% had CDI-2 total scores in the elevated range. Greater CDI-2 total scores were associated with poor sleep quality (ρ = 0.571; p = 0.02), EDS (ρ = 0.360; p = 0.05), and lower self-reported PA levels (ρ = −0.512; p < 0.01).ConclusionsAdolescents with narcolepsy report experiencing depressive symptoms, which are associated with poor sleep quality, EDS, and low PA levels. Strategies to improve nocturnal sleep quality and symptoms of EDS as well as promoting increased PA levels in adolescents with narcolepsy may provide an opportunity to improve depressive symptoms in this population. Multidisciplinary care with mental health and sleep specialists for adolescents with narcolepsy is needed.

Lai, Victor; Tong, Benjamin K; Tran, Carolin; Ricciardiello, Andrea; Donegan, Michelle; Murray, Nicholas P; Carberry, Jayne C; Eckert, Danny J

doi: 10.1093/sleep/zsz119pmid: 31180512

Study ObjectivesMandibular advancement splint (MAS) therapy is a well-tolerated alternative to continuous positive airway pressure for obstructive sleep apnea (OSA). Other therapies, including nasal expiratory positive airway pressure (EPAP) valves, can also reduce OSA severity. However, >50% of patients have an incomplete or no therapeutic response with either therapy alone and thus remain at risk of adverse health outcomes. Combining these therapies may yield greater efficacy to provide a therapeutic solution for many incomplete/nonresponders to MAS therapy. Thus, this study evaluated the efficacy of combination therapy with MAS plus EPAP in incomplete/nonresponders to MAS alone.MethodsTwenty-two people with OSA (apnea–hypopnea index [AHI] = 22 [13, 42] events/hr), who were incomplete/nonresponders (residual AHI > 5 events/hr) on an initial split-night polysomnography with a novel MAS device containing an oral airway, completed an additional split-night polysomnography with MAS + oral EPAP valve and MAS + oral and nasal EPAP valves (order randomized).ResultsCompared with MAS alone, MAS + oral EPAP significantly reduced the median total AHI, with further reductions with the MAS + oral/nasal EPAP combination (15 [10, 34] vs. 10 [7, 21] vs. 7 [3, 13] events/hr, p < 0.01). Larger reductions occurred in supine nonrapid eye movement AHI with MAS + oral/nasal EPAP combination therapy (ΔAHI = 23 events/hr, p < 0.01). OSA resolved (AHI < 5 events/hr) with MAS + oral/nasal EPAP in nine individuals and 13 had ≥50% reduction in AHI from no MAS. However, sleep efficiency was lower with MAS + oral/nasal EPAP versus MAS alone or MAS + oral EPAP (78 ± 19 vs. 87 ± 10 and 88 ± 10% respectively, p < 0.05).ConclusionsCombination therapy with a novel MAS device and simple oral or oro-nasal EPAP valves reduces OSA severity to therapeutic levels for a substantial proportion of incomplete/nonresponders to MAS therapy alone.Clinical TrialsName: Targeted combination therapy: Physiological mechanistic studies to inform treatment for obstructive sleep apnea (OSA)URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372279 Registration: ACTRN12617000492358 (Part C)

Barfield, Richard; Wang, Heming; Liu, Yongmei; Brody, Jennifer A; Swenson, Brenton; Li, Ruitong; Bartz, Traci M; Sotoodehnia, Nona; Chen, Yii-der I; Cade, Brian E; Chen, Han; Patel, Sanjay R; Zhu, Xiaofeng; Gharib, Sina A; Johnson, W Craig; Rotter, Jerome I; Saxena, Richa; Purcell, Shaun; Lin, Xihong; Redline, Susan;

Cross, Nathan E; Carrier, Julie; Postuma, Ronald B; Gosselin, Nadia; Kakinami, Lisa; Thompson, Cynthia; Chouchou, Florian; Dang-Vu, Thien Thanh

doi: 10.1093/sleep/zsz114pmid: 31089710

ObjectivesThis study examined the differences in cognitive function between middle-aged and older adults with insomnia disorder, insomnia symptoms only (ISO) or no insomnia symptoms (NIS), in the context of other health and lifestyle factors.MethodsTwenty-eight thousand four hundred eighty-five participants >45 years completed questionnaires, physical examinations, and neuropsychological testing across domains of processing speed, memory, and executive functions. An eight-question instrument assessed participants’ sleep, defining subjects with insomnia symptoms, probable insomnia disorder (PID), or NIS. The associations between these three groups and cognitive performance were examined with linear regression models adjusted for lifestyle and clinical factors.ResultsPID was identified in 1,068 participants (3.7% of the sample) while 7,813 (27.5%) experienced ISO. Participants with PID exhibited greater proportions of adverse medical and lifestyle features such as anxiety, depression, and diabetes than both other groups. Analyses adjusting for age, sex, education, as well as medical and lifestyle factors demonstrated that adults with PID exhibited declarative memory deficits (Rey Auditory Verbal Learning Test) compared with ISO or NIS. Adults with insomnia symptoms exhibited better performance on a task of mental flexibility than both other groups.ConclusionsThese findings suggest that insomnia disorder in middle-aged and older adults is associated with poorer health outcomes and worse memory performance than adults with insomnia symptoms alone or without any sleep complaints, even after adjustment for comorbidities. The assessment of longitudinal data within this cohort will be critical to understand if insomnia disorder may increase the risk of further cognitive decline.

Sprecher, Kate E; Ritchie, Hannah K; Burke, Tina M; Depner, Christopher M; Smits, Alexandra N; Dorrestein, Pieter C; Fleshner, Monika; Knight, Rob; Lowry, Christopher A; Turek, Fred W; Vitaterna, Martha H; Wright, Kenneth P

Achermann, Peter; Rusterholz, Thomas; Stucky, Benjamin; Olbrich, Eckehard

doi: 10.1093/sleep/zsz096pmid: 31173152

Falling asleep is a gradually unfolding process. We investigated the role of various oscillatory activities including sleep spindles and alpha and delta oscillations at sleep onset (SO) by automatically detecting oscillatory events. We used two datasets of healthy young males, eight with four baseline recordings, and eight with a baseline and recovery sleep after 40 h of sustained wakefulness. We analyzed the 2-min interval before SO (stage 2) and the five consecutive 2-min intervals after SO. The incidence of delta/theta events reached its maximum in the first 2-min episode after SO, while the frequency of them was continuously decreasing from stage 1 onwards, continuing over SO and further into deeper sleep. Interestingly, this decrease of the frequencies of the oscillations were not affected by increased sleep pressure, in contrast to the incidence which increased. We observed an increasing number of alpha events after SO, predominantly frontally, with their prevalence varying strongly across individuals. Sleep spindles started to occur after SO, with first an increasing then a decreasing incidence and a continuous decrease in their frequency. Again, the frequency of the spindles was not altered after sleep deprivation. Oscillatory events revealed derivation dependent aspects. However, these regional aspects were not specific of the process of SO but rather reflect a general sleep related phenomenon. No individual traits of SO features (incidence and frequency of oscillations) and their dynamics were observed. Delta/theta events are important features for the analysis of SO in addition to slow waves.