Advancing the sleep/wake schedule impacts the sleep of African-Americans more than European-Americans.

PubMed

Paech, Gemma M; Crowley, Stephanie J; Fogg, Louis F; Eastman, Charmane I

2017-01-01

There are differences in sleep duration between Blacks/African-Americans and Whites/European-Americans. Recently, we found differences between these ancestry groups in the circadian system, such as circadian period and the magnitude of phase shifts. Here we document the role of ancestry on sleep and cognitive performance before and after a 9-h advance in the sleep/wake schedule similar to flying east or having a large advance in sleep times due to shiftwork, both of which produce extreme circadian misalignment. Non-Hispanic African and European-Americans (N = 20 and 17 respectively, aged 21-43 years) were scheduled to four baseline days each with 8 h time in bed based on their habitual sleep schedule. This sleep/wake schedule was then advanced 9 h earlier for three days. Sleep was monitored using actigraphy. During the last two baseline/aligned days and the first two advanced/misaligned days, beginning 2 h after waking, cognitive performance was measured every 3 h using the Automated Neuropsychological Assessment Metrics (ANAM) test battery. Mixed model ANOVAs assessed the effects of ancestry (African-American or European-American) and condition (baseline/aligned or advanced/misaligned) on sleep and cognitive performance. There was decreased sleep and impaired performance in both ancestry groups during the advanced/misaligned days compared to the baseline/aligned days. In addition, African-Americans obtained less sleep than European-Americans, especially on the first two days of circadian misalignment. Cognitive performance did not differ between African-Americans and European-Americans during baseline days. During the two advanced/misaligned days, however, African-Americans tended to perform slightly worse compared to European-Americans, particularly at times corresponding to the end of the baseline sleep episodes. Advancing the sleep/wake schedule, creating extreme circadian misalignment, had a greater impact on the sleep of African-Americans than European-Americans. Ancestry differences in sleep appear to be exacerbated when the sleep/wake schedule is advanced, which may have implications for individuals undertaking shiftwork and transmeridian travel.

Comparison of Two Watch Schedules for Personnel at the White House Military Office President's Emergency Operations Center.

PubMed

Shattuck, Nita Lewis; Matsangas, Panagiotis; Eriksen, Elke; Kulubis, Spiros

2015-08-01

The aim of this study was to assess effectiveness of an alternative, 24-hr-on/72-hr-off watchstanding schedule on sleep and morale of personnel assigned to the President's Emergency Operations Center (PEOC). As part of the White House Military Office, PEOC personnel historically worked a 12-hr "Panama" watch schedule. Personnel reported experiencing chronic insufficient and disrupted sleep patterns and sought advice for improving their watchstanding schedule. Participants (N = 14 active-duty military members, ages 29 to 42 years) completed the Profile of Mood State (POMS) three times: before, during, and after switching to the alternative schedule with 5-hr sleep periods built into their workday. Participants completed a poststudy questionnaire to assess individual schedule preferences. Sleep was measured actigraphically, supplemented by activity logs. As indicated by POMS scores, mood improved significantly on the new schedule. Although average total sleep amount did not change substantively, the timing of sleep was more consistent on the new schedule, resulting in better sleep hygiene. PEOC personnel overwhelmingly preferred the new schedule, reporting not only that they felt more rested but that the new schedule was more conducive to the demands of family life. Demands of family life and time spent commuting were found to be critical factors for acceptance of the alternative schedule. This new schedule will be most effective if personnel adhere to the scheduled rest periods assigned during their 24-hr duty. A successful schedule should avoid conflicts between social life and operational demands. Results may lead to changes in the work schedules of other departments with similar 24/7 responsibilities. © 2015, Human Factors and Ergonomics Society.

Sleep schedules and school performance in Indigenous Australian children.

PubMed

Blunden, Sarah; Magee, Chris; Attard, Kelly; Clarkson, Larissa; Caputi, Peter; Skinner, Timothy

2018-04-01

Sleep duration and sleep schedule variability have been related to negative health and well-being outcomes in children, but little is known about Australian Indigenous children. Data for children aged 7-9 years came from the Australian Longitudinal Study of Indigenous Children and the National Assessment Program-Literacy and Numeracy (NAPLAN). Latent class analysis determined sleep classes taking into account sleep duration, bedtimes, waketimes, and variability in bedtimes from weekdays to weekends. Regression models tested whether the sleep classes were cross-sectionally associated with grade 3 NAPLAN scores. Latent change score modeling then examined whether the sleep classes predicted changes in NAPLAN performance from grades 3 to 5. Five sleep schedule classes were identified: normative sleep, early risers, long sleep, variable sleep, and short sleep. Overall, long sleepers performed best, with those with reduced sleep (short sleepers and early risers) performing the worse on grammar, numeracy, and writing performance. Latent change score results also showed that long sleepers performed best in spelling and writing and short sleepers and typical sleepers performed the worst over time. In this sample of Australian Indigenous children, short sleep was associated with poorer school performance compared with long sleep, with this performance worsening over time for some performance indicators. Other sleep schedules (eg, early wake times and variable sleep) also had some relationships with school performance. As sleep scheduling is modifiable, this offers opportunity for improvement in sleep and thus performance outcomes for these and potentially all children. Copyright © 2018 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Operational assessment of the 5-h on/10-h off watchstanding schedule on a US Navy ship: sleep patterns, mood and psychomotor vigilance performance of crewmembers in the nuclear reactor department.

PubMed

Shattuck, Nita Lewis; Matsangas, Panagiotis

2016-05-01

We assessed sleep patterns, psychomotor vigilance performance, work demands and mood of 77 crewmembers of USS NIMITZ (CVN-68) on the rotating 5-h on/10-h off (5/10) watchstanding schedule. Within the 3-day cycle of the 5/10, sleep occurred at distinctly different times each day. On two of these days, sailors typically received only brief, 4-h sleep episodes followed by periods of sustained wakefulness (approximately 22 and 20 h). Crewmembers received approximately seven hours of sleep daily, but reported excessive fatigue and dissatisfaction with their schedule. Crewmembers' mood worsened significantly over the course of the underway phase. Psychomotor vigilance performance (reaction times, lapses) was significantly degraded compared to performance when working circadian-aligned schedules. Overall, standing watch on the 5/10 schedule, combined with other work duties, resulted in poor sleep hygiene. Crewmembers on the 5/10 experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep. Practitioner summary: We assessed crewmembers' sleep patterns, psychomotor vigilance performance and work demands when working a rotating 5-h on/10-h off (5/10) watchstanding schedule. The 5/10, combined with other work duties, resulted in poor sleep hygiene. Crewmembers experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep.

A Unified Model of Performance: Validation of its Predictions across Different Sleep/Wake Schedules

PubMed Central

Ramakrishnan, Sridhar; Wesensten, Nancy J.; Balkin, Thomas J.; Reifman, Jaques

2016-01-01

Study Objectives: Historically, mathematical models of human neurobehavioral performance developed on data from one sleep study were limited to predicting performance in similar studies, restricting their practical utility. We recently developed a unified model of performance (UMP) to predict the effects of the continuum of sleep loss—from chronic sleep restriction (CSR) to total sleep deprivation (TSD) challenges—and validated it using data from two studies of one laboratory. Here, we significantly extended this effort by validating the UMP predictions across a wide range of sleep/wake schedules from different studies and laboratories. Methods: We developed the UMP on psychomotor vigilance task (PVT) lapse data from one study encompassing four different CSR conditions (7 d of 3, 5, 7, and 9 h of sleep/night), and predicted performance in five other studies (from four laboratories), including different combinations of TSD (40 to 88 h), CSR (2 to 6 h of sleep/night), control (8 to 10 h of sleep/night), and nap (nocturnal and diurnal) schedules. Results: The UMP accurately predicted PVT performance trends across 14 different sleep/wake conditions, yielding average prediction errors between 7% and 36%, with the predictions lying within 2 standard errors of the measured data 87% of the time. In addition, the UMP accurately predicted performance impairment (average error of 15%) for schedules (TSD and naps) not used in model development. Conclusions: The unified model of performance can be used as a tool to help design sleep/wake schedules to optimize the extent and duration of neurobehavioral performance and to accelerate recovery after sleep loss. Citation: Ramakrishnan S, Wesensten NJ, Balkin TJ, Reifman J. A unified model of performance: validation of its predictions across different sleep/wake schedules. SLEEP 2016;39(1):249–262. PMID:26518594

Advancing the sleep/wake schedule impacts the sleep of African-Americans more than European-Americans

PubMed Central

Crowley, Stephanie J.; Fogg, Louis F.; Eastman, Charmane I.

2017-01-01

There are differences in sleep duration between Blacks/African-Americans and Whites/European-Americans. Recently, we found differences between these ancestry groups in the circadian system, such as circadian period and the magnitude of phase shifts. Here we document the role of ancestry on sleep and cognitive performance before and after a 9-h advance in the sleep/wake schedule similar to flying east or having a large advance in sleep times due to shiftwork, both of which produce extreme circadian misalignment. Non-Hispanic African and European-Americans (N = 20 and 17 respectively, aged 21–43 years) were scheduled to four baseline days each with 8 h time in bed based on their habitual sleep schedule. This sleep/wake schedule was then advanced 9 h earlier for three days. Sleep was monitored using actigraphy. During the last two baseline/aligned days and the first two advanced/misaligned days, beginning 2 h after waking, cognitive performance was measured every 3 h using the Automated Neuropsychological Assessment Metrics (ANAM) test battery. Mixed model ANOVAs assessed the effects of ancestry (African-American or European-American) and condition (baseline/aligned or advanced/misaligned) on sleep and cognitive performance. There was decreased sleep and impaired performance in both ancestry groups during the advanced/misaligned days compared to the baseline/aligned days. In addition, African-Americans obtained less sleep than European-Americans, especially on the first two days of circadian misalignment. Cognitive performance did not differ between African-Americans and European-Americans during baseline days. During the two advanced/misaligned days, however, African-Americans tended to perform slightly worse compared to European-Americans, particularly at times corresponding to the end of the baseline sleep episodes. Advancing the sleep/wake schedule, creating extreme circadian misalignment, had a greater impact on the sleep of African-Americans than European-Americans. Ancestry differences in sleep appear to be exacerbated when the sleep/wake schedule is advanced, which may have implications for individuals undertaking shiftwork and transmeridian travel. PMID:29059251

The military performance of soldiers in sustained operations.

PubMed

Haslam, D R

1984-03-01

Two 9-d tactical defensive exercises were carried out. The first assessed and compared the performance of three platoons of infantry scheduled for either 0, 1.5, or 3 h of sleep in every 24 h, and the second determined whether soldiers are likely to remain militarily effective during a period of partial sleep loss following a period with no scheduled sleep at all. To this end, 10 infantry soldiers were scheduled for 4 h of sleep in every 24 for a 6-d period following a 3.75-d period without any scheduled sleep. Performance, physical fitness, and mood were assessed throughout both exercises. Results indicated that the effects of sleep loss are psychological rather than physiological; soldiers are likely to be militarily ineffective after 48-72 h without sleep; and a small amount of recovery sleep relative to the amount lost has very beneficial effects.

Crew Factors in Flight Operations 7: Psychophysiological Responses to Overnight Cargo Operations

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Gregory, Kevin B.; Connell, Linda J.; Miller, Donna L.; Graeber, R. Curtis; Rosekind, Mark R.

1996-01-01

To document the psychophysiological effects of flying overnight cargo operations, 41 B-727 crew members (average age 38 yr) were monitored before, during, and after one of two typical 8-day trip patterns. During daytime layovers, the average sleep episode was 3 hr (41%) shorter than nighttime sleeps and was rated as lighter, less restorative, and poorer overall. Sleep was frequently split into several episodes and totaled 1.2 hr less per 24 hr than on pretrip days. Each trip pattern included a night off, which was an effective countermeasure against the accumulating sleep debt. The organization of sleep during daytime layovers reflected the interaction of duty timing with circadian physiology. The circadian temperature rhythm did not adapt completely to the inverted wake-rest schedule on duty days, being delayed by about 3 hr. Highest subjective fatigue and lowest activation occurred around the time of the temperature minimum. On duty days, reports of headaches increased by 400%, of congested nose by 200%, and of burning eyes by 900%. Crew members also reported eating more snacks. Compared with daytime short-haul air-transport operations, the overnight cargo trips included fewer duty and flight hours, and had longer layovers. Overnight cargo crews also averaged 5.4 yr younger than their daytime short-haul counterparts. On trips, both groups lost a comparable amount of sleep per 24 hr, but the overnight cargo crews had shorter individual sleep episodes and more broken sleep. These data clearly demonstrate that overnight cargo operations, like other night work, involve physiological disruption not found in comparable daytime operations.

Prioritizing sleep for healthy work schedules.

PubMed

Takahashi, Masaya

2012-03-13

Good sleep is advantageous to the quality of life. Sleep-related benefits are particularly helpful for the working class, since poor or inadequate amounts of sleep degrade work productivity and overall health. This review paper explores the essential role of sleep in healthy work schedules and primarily focuses on the timing of sleep in relation to the work period (that is, before, during and after work). Data from laboratory, field and modeling studies indicate that consistent amounts of sleep prior to work are fundamental to improved performance and alertness in the workplace. In addition, planned naps taken during work maintain appropriate levels of waking function for both daytime and night-time work. Clearly, sufficient sleep after work is vital in promoting recovery from fatigue. Recent data also suggest that the time interval between shifts should be adjusted according to the biological timing of sleep. Although sleep is more likely to be replaced by job and other activities in the real life, research shows that it is worthwhile to revise the work schedules in order to optimize sleep before, sometime during and after the work period. Therefore, we suggest establishing work-sleep balance, similar to work-life balance, as a principle for designing and improving work schedules.

Prioritizing sleep for healthy work schedules

PubMed Central

2012-01-01

Good sleep is advantageous to the quality of life. Sleep-related benefits are particularly helpful for the working class, since poor or inadequate amounts of sleep degrade work productivity and overall health. This review paper explores the essential role of sleep in healthy work schedules and primarily focuses on the timing of sleep in relation to the work period (that is, before, during and after work). Data from laboratory, field and modeling studies indicate that consistent amounts of sleep prior to work are fundamental to improved performance and alertness in the workplace. In addition, planned naps taken during work maintain appropriate levels of waking function for both daytime and night-time work. Clearly, sufficient sleep after work is vital in promoting recovery from fatigue. Recent data also suggest that the time interval between shifts should be adjusted according to the biological timing of sleep. Although sleep is more likely to be replaced by job and other activities in the real life, research shows that it is worthwhile to revise the work schedules in order to optimize sleep before, sometime during and after the work period. Therefore, we suggest establishing work-sleep balance, similar to work-life balance, as a principle for designing and improving work schedules. PMID:22738292

Atypical work schedules are associated with poor sleep quality and mental health in Taiwan female nurses.

PubMed

Lin, Pei-Chen; Chen, Chung-Hey; Pan, Shung-Mei; Pan, Chih-Hong; Chen, Chiou-Jong; Chen, Yao-Mei; Hung, Hsin-Chia; Wu, Ming-Tsang

2012-11-01

To investigate the effects of shift work schedules on sleep quality and mental health in female nurses in south Taiwan. This study recruited 1,360 female registered nurses in the Kaohsiung area for the first survey, and among them, 769 nurses had a rotation shift schedule. Among the 769 rotation shift work nurses, 407 completed another second survey 6-10 months later. Data collection included demographic variables, work status, shift work schedule, sleep quality (Pittsburgh Sleep Quality Index), and mental health (Chinese Health Questionnaire-12). Nurses on rotation shift had the poor sleep quality and mental health compared to nurses on day shift. The nurses on rotation shift had a relatively higher OR of reporting poor sleep quality and poor mental health (OR, 2.26; 95% CI, 1.57-3.28; and OR, 1.91; 95% CI, 1.39-2.63, respectively). Additionally, rotation shift nurses who had ≥2 days off after their most recent night shifts showed significantly improved sleep quality and mental health (PSQI decreased of 1.23 and CHQ-12 decreased of 0.86, respectively). Comparison of sleep quality between the first and second surveys showed aggravated sleep quality only in nurses who had an increased frequency of night shifts. Female nurses who have a rotation shift work schedule tend to experience poor sleep quality and mental health, but their sleep quality and mental health improve if they have ≥2 days off after their most recent night shifts. This empirical information is useful for optimizing work schedules for nurses.

Effects of an irregular bedtime schedule on sleep quality, daytime sleepiness, and fatigue among university students in Taiwan.

PubMed

Kang, Jiunn-Horng; Chen, Shih-Ching

2009-07-19

An irregular bedtime schedule is a prevalent problem in young adults, and could be a factor detrimentally affecting sleep quality. The goal of the present study was to explore the association between an irregular bedtime schedule and sleep quality, daytime sleepiness, and fatigue among undergraduate students in Taiwan. A total of 160 students underwent a semi-structured interview and completed a survey comprising 4 parts: Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and a rating of irregular bedtime frequency. Participants were grouped into 3 groups in terms of irregular bedtime frequency: low, intermediate, or high according to their 2-week sleep log. To screen for psychological disorders or distress that may have affected responses on the sleep assessment measures, the Chinese health questionnaire-12 (CHQ-12) was also administered. We found an increase in bedtime schedule irregularity to be significantly associated with a decrease in average sleep time per day (Spearman r = -0.22, p = 0.05). Multivariate regression analysis revealed that irregular bedtime frequency and average sleep time per day were correlated with PSQI scores, but not with ESS or FSS scores. A significant positive correlation between irregular bedtime frequency and PSQI scores was evident in the intermediate (partial r = 0.18, p = 0.02) and high (partial r = 0.15, p = 0.05) frequency groups as compared to low frequency group. The results of our study suggest a high prevalence of both an irregular bedtime schedule and insufficient sleep among university students in Taiwan. Students with an irregular bedtime schedule may experience poor sleep quality. We suggest further research that explores the mechanisms involved in an irregular bedtime schedule and the effectiveness of interventions for improving this condition.

Pre-Scheduled and Self Organized Sleep-Scheduling Algorithms for Efficient K-Coverage in Wireless Sensor Networks

PubMed Central

Hwang, I-Shyan

2017-01-01

The K-coverage configuration that guarantees coverage of each location by at least K sensors is highly popular and is extensively used to monitor diversified applications in wireless sensor networks. Long network lifetime and high detection quality are the essentials of such K-covered sleep-scheduling algorithms. However, the existing sleep-scheduling algorithms either cause high cost or cannot preserve the detection quality effectively. In this paper, the Pre-Scheduling-based K-coverage Group Scheduling (PSKGS) and Self-Organized K-coverage Scheduling (SKS) algorithms are proposed to settle the problems in the existing sleep-scheduling algorithms. Simulation results show that our pre-scheduled-based KGS approach enhances the detection quality and network lifetime, whereas the self-organized-based SKS algorithm minimizes the computation and communication cost of the nodes and thereby is energy efficient. Besides, SKS outperforms PSKGS in terms of network lifetime and detection quality as it is self-organized. PMID:29257078

Sleep pattern and decision-making in physicians from mobile emergency care service with 12-h work schedules.

PubMed

Castro, Eleni de Araújo Sales; de Almondes, Katie Moraes

2018-06-01

Shift work schedules are biological standpoint worse because compel the body to anticipate periods of wakefulness and sleep and thus eventually cause a disruption of biological rhythms. The objective of this study is to evaluate the sleep pattern and decision-making in physicians working in mobile units of emergency attention undergoing day shift and rotating shift. The study included 26 physicians. The instruments utilized were a sociodemographic questionnaire, the Pittsburgh Sleep Quality Index, the Sleep Habits Questionnaire, the Epworth Sleepiness Scale and Chronotype Identification Questionnaire of Horne-Ostberg, the Iowa Gambling Task (IGT) and hypothetical scenarios of decision-making created according to the Policy-Capturing Technique. For inclusion and exclusion criteria, the participants answered the Chalder Fatigue Scale, the Beck Anxiety Inventory, the Beck Depression Inventory and the Inventory of Stress Symptoms for adults of Lipp. It was found good sleep quality for physicians on day shift schedule and bad sleep quality for physicians on rotating shift schedule. The IGT measure showed no impairment in decision-making, but the hypothetical scenarios revealed impairment decision-making during the shift for both schedules. Good sleep quality was related to a better performance in decision-making. Good sleep quality seems to influence a better performance in decision-making.

2B-Alert Web: An Open-Access Tool for Predicting the Effects of Sleep/Wake Schedules and Caffeine Consumption on Neurobehavioral Performance.

PubMed

Reifman, Jaques; Kumar, Kamal; Wesensten, Nancy J; Tountas, Nikolaos A; Balkin, Thomas J; Ramakrishnan, Sridhar

2016-12-01

Computational tools that predict the effects of daily sleep/wake amounts on neurobehavioral performance are critical components of fatigue management systems, allowing for the identification of periods during which individuals are at increased risk for performance errors. However, none of the existing computational tools is publicly available, and the commercially available tools do not account for the beneficial effects of caffeine on performance, limiting their practical utility. Here, we introduce 2B-Alert Web, an open-access tool for predicting neurobehavioral performance, which accounts for the effects of sleep/wake schedules, time of day, and caffeine consumption, while incorporating the latest scientific findings in sleep restriction, sleep extension, and recovery sleep. We combined our validated Unified Model of Performance and our validated caffeine model to form a single, integrated modeling framework instantiated as a Web-enabled tool. 2B-Alert Web allows users to input daily sleep/wake schedules and caffeine consumption (dosage and time) to obtain group-average predictions of neurobehavioral performance based on psychomotor vigilance tasks. 2B-Alert Web is accessible at: https://2b-alert-web.bhsai.org. The 2B-Alert Web tool allows users to obtain predictions for mean response time, mean reciprocal response time, and number of lapses. The graphing tool allows for simultaneous display of up to seven different sleep/wake and caffeine schedules. The schedules and corresponding predicted outputs can be saved as a Microsoft Excel file; the corresponding plots can be saved as an image file. The schedules and predictions are erased when the user logs off, thereby maintaining privacy and confidentiality. The publicly accessible 2B-Alert Web tool is available for operators, schedulers, and neurobehavioral scientists as well as the general public to determine the impact of any given sleep/wake schedule, caffeine consumption, and time of day on performance of a group of individuals. This evidence-based tool can be used as a decision aid to design effective work schedules, guide the design of future sleep restriction and caffeine studies, and increase public awareness of the effects of sleep amounts, time of day, and caffeine on alertness. © 2016 Associated Professional Sleep Societies, LLC.

A Unified Model of Performance: Validation of its Predictions across Different Sleep/Wake Schedules.

PubMed

Ramakrishnan, Sridhar; Wesensten, Nancy J; Balkin, Thomas J; Reifman, Jaques

2016-01-01

Historically, mathematical models of human neurobehavioral performance developed on data from one sleep study were limited to predicting performance in similar studies, restricting their practical utility. We recently developed a unified model of performance (UMP) to predict the effects of the continuum of sleep loss-from chronic sleep restriction (CSR) to total sleep deprivation (TSD) challenges-and validated it using data from two studies of one laboratory. Here, we significantly extended this effort by validating the UMP predictions across a wide range of sleep/wake schedules from different studies and laboratories. We developed the UMP on psychomotor vigilance task (PVT) lapse data from one study encompassing four different CSR conditions (7 d of 3, 5, 7, and 9 h of sleep/night), and predicted performance in five other studies (from four laboratories), including different combinations of TSD (40 to 88 h), CSR (2 to 6 h of sleep/night), control (8 to 10 h of sleep/night), and nap (nocturnal and diurnal) schedules. The UMP accurately predicted PVT performance trends across 14 different sleep/wake conditions, yielding average prediction errors between 7% and 36%, with the predictions lying within 2 standard errors of the measured data 87% of the time. In addition, the UMP accurately predicted performance impairment (average error of 15%) for schedules (TSD and naps) not used in model development. The unified model of performance can be used as a tool to help design sleep/wake schedules to optimize the extent and duration of neurobehavioral performance and to accelerate recovery after sleep loss. © 2016 Associated Professional Sleep Societies, LLC.

Chronotype, Light Exposure, Sleep, and Daytime Functioning in High School Students Attending Morning or Afternoon School Shifts: An Actigraphic Study.

PubMed

Martin, Jeanne Sophie; Gaudreault, Michael M; Perron, Michel; Laberge, Luc

2016-04-01

Adolescent maturation is associated with delays of the endogenous circadian phase. Consequently, early school schedules may lead to a mismatch between internal and external time, which can be detrimental to adolescent sleep and health. In parallel, chronotype is known to play a role in adolescent health; evening chronotype adolescents are at higher risk for sleep problems and lower academic achievement. In the summer of 2008, Kénogami High School (Saguenay, Canada) was destroyed by fire. Kénogami students were subsequently relocated to Arvida High School (situated 5.3 km away) for the 2008-2009 academic year. A dual school schedule was implemented, with Arvida students attending a morning schedule (0740-1305 h) and Kénogami students an afternoon schedule (1325-1845 h). This study aimed to investigate the effects of such school schedules and chronotype on sleep, light exposure, and daytime functioning. Twenty-four morning and 33 afternoon schedule students wore an actigraph during 7 days to measure sleep and light exposure. Academic achievement was obtained from school. Subjects completed validated questionnaires on daytime sleepiness, psychological distress, social rhythms, school satisfaction, alcohol, and chronotype. Overall, afternoon schedule students had longer sleep duration, lower sleepiness, and lower light exposure than morning schedule students. Evening chronotypes (E-types) reported higher levels of sleepiness than morning chronotypes (M-types) in both morning and afternoon schedules. Furthermore, M-types attending the morning schedule reported higher sleepiness than M-types attending the afternoon schedule. No difference was found between morning and afternoon schedule students with regard to academic achievement, psychological distress, social rhythms, school satisfaction, and alcohol consumption. However, in both schedules, M-type had more regular social rhythms and lower alcohol consumption. In summary, this study emphasizes that an early school schedule is associated with detrimental effects in terms of sleep deprivation and daytime sleepiness, even for M-types. Furthermore, irrespective of school schedule, E-type adolescents face an increased risk for poor daytime functioning. © 2016 The Author(s).

Medications for Sleep Schedule Adjustments in Athletes.

PubMed

Baird, Matthew B; Asif, Irfan M

Sleep schedule adjustments are common requirements of modern-day athletes. Many nonpharmacologic and pharmacologic strategies exist to facilitate circadian rhythm shifts to maximize alertness and performance during competition. This review summarizes the evidence for commonly used pharmacologic agents and presents recommendations for the sports medicine provider. MEDLINE searches were performed using the following keywords: sleep aids, circadian rhythm adjustment, athletes and sleep, caffeine and sports, melatonin and athletes, and sleep aids and sports. Pertinent articles were extracted and discussed. Clinical review. Level 2. There are very few available studies investigating pharmacologic sleep aids in athletes. Data from studies involving shift workers and airline personnel are more abundant and were used to formulate recommendations and conclusions. Melatonin, caffeine, and nonbenzodiazepine sleep aids have a role in facilitating sleep schedule changes in athletes and maximizing sports performance through sleep enhancement.

Sleep and cognitive performance of African-Americans and European-Americans before and during circadian misalignment produced by an abrupt 9-h delay in the sleep/wake schedule

PubMed Central

Crowley, Stephanie J.; Eastman, Charmane I.

2017-01-01

We conducted two studies of circadian misalignment in non-Hispanic African and European-Americans. In the first, the sleep/wake (light/dark) schedule was advanced 9 h, similar to flying east, and in the second these schedules were delayed 9 h, similar to flying west or sleeping during the day after night work. We confirmed that the free-running circadian period is shorter in African-Americans compared to European-Americans, and found differences in the magnitude and direction of circadian rhythm phase shifts which were related to the circadian period. The sleep and cognitive performance data from the first study (published in this journal) documented the impairment in both ancestry groups due to this extreme circadian misalignment. African-Americans slept less and performed slightly worse during advanced/misaligned days than European-Americans. The current analysis is of sleep and cognitive performance from the second study. Participants were 23 African-Americans and 22 European-Americans (aged 18–44 years). Following four baseline days (8 h time in bed, based on habitual sleep), the sleep/wake schedule was delayed by 9 h for three days. Sleep was monitored using actigraphy. During the last two baseline/aligned days and the first two delayed/misaligned days, beginning 2 h after waking, cognitive performance was assessed every 3 h using the Automated Neuropsychological Assessment Metrics (ANAM) battery. Mixed model ANOVAs assessed the effects of ancestry (African-American or European-American) and condition (baseline/aligned or delayed/misaligned) on sleep and performance. There was decreased sleep and impaired cognitive performance in both ancestry groups during the two delayed/misaligned days relative to baseline/aligned days. Sleep and cognitive performance did not differ between African-Americans and European-Americans during either baseline/aligned or delayed/misaligned days. While our previous work showed that an advance in the sleep/wake schedule impaired the sleep of African-Americans more than European-Americans, delaying the sleep/wake schedule impaired the sleep and cognitive performance of African-Americans and European-Americans equally. PMID:29073187

Physical exercise accelerates reentrainment of human sleep-wake cycle but not of plasma melatonin rhythm to 8-h phase-advanced sleep schedule.

PubMed

Yamanaka, Yujiro; Hashimoto, Satoko; Tanahashi, Yusuke; Nishide, Shin-Ya; Honma, Sato; Honma, Ken-Ichi

2010-03-01

Effects of timed physical exercise were examined on the reentrainment of sleep-wake cycle and circadian rhythms to an 8-h phase-advanced sleep schedule. Seventeen male adults spent 12 days in a temporal isolation facility with dim light conditions (<10 lux). The sleep schedule was phase-advanced by 8 h from their habitual sleep times for 4 days, which was followed by a free-run session for 6 days, during which the subjects were deprived of time cues. During the shift schedule, the exercise group (n = 9) performed physical exercise with a bicycle ergometer in the early and middle waking period for 2 h each. The control group (n = 8) sat on a chair at those times. Their sleep-wake cycles were monitored every day by polysomnography and/or weight sensor equipped with a bed. The circadian rhythm in plasma melatonin was measured on the baseline day before phase shift: on the 4th day of shift schedule and the 5th day of free-run. As a result, the sleep-onset on the first day of free-run in the exercise group was significantly phase-advanced from that in the control and from the baseline. On the other hand, the circadian melatonin rhythm was significantly phase-delayed in the both groups, showing internal desynchronization of the circadian rhythms. The sleep-wake cycle resynchronized to the melatonin rhythm by either phase-advance or phase-delay shifts in the free-run session. These findings indicate that the reentrainment of the sleep-wake cycle to a phase-advanced schedule occurs independent of the circadian pacemaker and is accelerated by timed physical exercise.

Sleep disorders - overview

MedlinePlus

... Hypersomina; Daytime sleepiness; Sleep rhythm; Sleep disruptive behaviors; Jet lag ... disrupted sleep schedule include: Irregular sleep-wake syndrome Jet lag syndrome Shift work sleep disorder Delayed sleep ...

Effects of sleep schedules on commercial motor vehicle driver performance

DOT National Transportation Integrated Search

2000-05-01

The project entitled "Effects of Sleep Schedules on Commercial Motor Vehicle Driver Performance" was comprised of two studies; a field study and a laboratory study. In the field study, wrist actigraphy was used to determine amounts of sleep in long-v...

A global quantification of "normal" sleep schedules using smartphone data.

PubMed

Walch, Olivia J; Cochran, Amy; Forger, Daniel B

2016-05-01

The influence of the circadian clock on sleep scheduling has been studied extensively in the laboratory; however, the effects of society on sleep remain largely unquantified. We show how a smartphone app that we have developed, ENTRAIN, accurately collects data on sleep habits around the world. Through mathematical modeling and statistics, we find that social pressures weaken and/or conceal biological drives in the evening, leading individuals to delay their bedtime and shorten their sleep. A country's average bedtime, but not average wake time, predicts sleep duration. We further show that mathematical models based on controlled laboratory experiments predict qualitative trends in sunrise, sunset, and light level; however, these effects are attenuated in the real world around bedtime. Additionally, we find that women schedule more sleep than men and that users reporting that they are typically exposed to outdoor light go to sleep earlier and sleep more than those reporting indoor light. Finally, we find that age is the primary determinant of sleep timing, and that age plays an important role in the variability of population-level sleep habits. This work better defines and personalizes "normal" sleep, produces hypotheses for future testing in the laboratory, and suggests important ways to counteract the global sleep crisis.

Shift Schedules and Intern Work Hours, Patient Numbers, Conference Attendance, and Sleep at a Single Pediatric Residency Program.

PubMed

Kocolas, Irene; Day, Kristen; King, Marta; Stevenson, Adam; Sheng, Xiaoming; Hobson, Wendy; Bruse, Jaime; Bale, James

2017-03-01

The effects of 2011 Accreditation Council on Graduate Medical Education (ACGME) duty hour standards on intern work hours, patient load, conference attendance, and sleep have not been fully determined. We prospectively compared intern work hours, patient numbers, conference attendance, sleep duration, pattern, and quality in a 2011 ACGME duty hour-compliant shift schedule with a 2003 ACGME duty hour-compliant call schedule at a single pediatric residency program. Interns were assigned to shift or call schedules during 4 alternate months in the winter of 2010-2011. Work hours, patient numbers, conference attendance, sleep duration, pattern, and quality were tracked. Interns worked significantly fewer hours per week on day (73.2 hours) or night (71.6 hours) shifts than during q4 call (79.6 hours; P < .01). During high census months, shift schedule interns cared for significantly more patients/day (8.1/day shift vs 6.2/call; P < .001) and attended significantly fewer conferences than call schedule interns. Night shift interns slept more hours per 24-hour period than call schedule interns (7.2 ± 0.5 vs 6.3 ± 0.9 hours; P < .05) and had more consistent sleep patterns. A shift schedule resulted in reduced intern work hours and improved sleep duration and pattern. Although intern didactic conference attendance declined significantly during high census months, opportunities for experiential learning remained robust with unchanged or increased intern patient numbers. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

"Sleep well, our tough heroes!"--in adolescence, greater mental toughness is related to better sleep schedules.

PubMed

Brand, Serge; Gerber, Markus; Kalak, Nadeem; Kirov, Roumen; Lemola, Sakari; Clough, Peter J; Pühse, Uwe; Holsboer-Trachsler, Edith

2014-01-01

Mental toughness (MT) is understood as the display of confidence, commitment, challenge, and control. The aim of this study was to explore the extent to which greater MT is associated with subjectively assessed sleep among adolescents. A total of 284 adolescents (M = 18.26 years) completed a series of questionnaires assessing MT, psychological functioning, and sleep. Greater MT was significantly associated with better sleep quality, shorter sleep onset latency, fewer awakenings after sleep onset, and longer sleep duration. Greater MT was also associated with less perceived stress and less depressive symptoms. MT was directly and indirectly associated with sleep quality. Mentally tough adolescents report good sleep quality and sleep schedules, along with psychological wellbeing.

Daytime Sleepiness Increases With Age in Early Adolescence: A Sleep Restriction Dose-Response Study.

PubMed

Campbell, Ian G; Burright, Christopher S; Kraus, Amanda M; Grimm, Kevin J; Feinberg, Irwin

2017-05-01

Daytime sleepiness increases across adolescence. This increase is commonly attributed to insufficient sleep durations resulting from increasingly limited time in bed. We tested the effects of 3 sleep schedules on daytime sleepiness and whether these effects changed with age in early adolescence. In 77 children ranging in age from 9.9 to 14 years, objective (multiple sleep latency test [MSLT]) and subjective (Karolinska sleepiness scale [KSS]) sleepiness was measured following 4 consecutive nights of either 7, 8.5, or 10 hours in bed. All participants completed all 3 sleep schedules. The order in which they completed the schedules was not randomized but was accounted for in all statistical analyses. Time in bed restriction decreased sleep duration and increased objective and subjective daytime sleepiness. Although the sleep durations did not change with age, the likelihood of falling asleep during the MSLT increased with age. Nevertheless, sleep restriction produced a greater increase in MSLT-measured sleepiness in younger participants. Subjective sleepiness measured with the KSS increased with shorter sleep duration, but this effect did not change with age. Increasing objective daytime sleepiness in early adolescence cannot simply be attributed to reduced sleep due to restricted sleep schedules. We propose that some of the increased daytime sleepiness of adolescents is a consequence of adolescent brain reorganization driven by synaptic pruning which decreases the intensity of waking brain activity. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Sick and tired: how molecular regulators of human sleep schedules and duration impact immune function.

PubMed

Kurien, Philip A; Chong, S Y Christin; Ptáček, Louis J; Fu, Ying-Hui

2013-10-01

Why do we need to sleep? What regulates when we sleep? And what dictates the number of hours we require? These are often viewed as three separate biological questions. Here, we propose they share molecular etiologies, whereby regulators of sleep schedules and sleep duration also govern the physiological purposes of sleep. To support our hypothesis, we review Mendelian human genetic variants sufficient to advance sleep-wake onset (PER2) and shorten sleep length (DEC2), and evaluate their emerging roles in immune responses that may rely on a sound night of slumber. Copyright © 2013 Elsevier Ltd. All rights reserved.

Circadian phase, dynamics of subjective sleepiness and sensitivity to blue light in young adults complaining of a delayed sleep schedule.

PubMed

Moderie, Christophe; Van der Maren, Solenne; Dumont, Marie

2017-06-01

To assess factors that might contribute to a delayed sleep schedule in young adults with sub-clinical features of delayed sleep phase disorder. Two groups of 14 young adults (eight women) were compared: one group complaining of a delayed sleep schedule and a control group with an earlier bedtime and no complaint. For one week, each subject maintained a target bedtime reflecting their habitual sleep schedule. Subjects were then admitted to the laboratory for the assessment of circadian phase (dim light melatonin onset), subjective sleepiness, and non-visual light sensitivity. All measures were timed relative to each participant's target bedtime. Non-visual light sensitivity was evaluated using subjective sleepiness and salivary melatonin during 1.5-h exposure to blue light, starting one hour after target bedtime. Compared to control subjects, delayed subjects had a later circadian phase and a slower increase of subjective sleepiness in the late evening. There was no group difference in non-visual sensitivity to blue light, but we found a positive correlation between melatonin suppression and circadian phase within the delayed group. Our results suggest that a late circadian phase, a slow build-up of sleep need, and an increased circadian sensitivity to blue light contribute to the complaint of a delayed sleep schedule. These findings provide targets for strategies aiming to decreasing the severity of a sleep delay and the negative consequences on daytime functioning and health. Copyright © 2017 Elsevier B.V. All rights reserved.

A unique, fast-forwards rotating schedule with 12-h long shifts prevents chronic sleep debt.

PubMed

Fischer, Dorothee; Vetter, Céline; Oberlinner, Christoph; Wegener, Sven; Roenneberg, Till

2016-01-01

Sleep debt--together with circadian misalignment--is considered a central factor for adverse health outcomes associated with shift work. Here, we describe in detail sleep-wake behavior in a fast-forward rotating 12-h shift schedule, which involves at least 24 hours off after each shift and thus allows examining the role of immediate recovery after shift-specific sleep debt. Thirty-five participants at two chemical plants in Germany were chronotyped using the Munich ChronoType Questionnaire for Shift-Workers (MCTQ(Shift)) and wore actimeters throughout the two-week study period. From these actimetry recordings, we computed sleep and nap duration, social jetlag (a measure of circadian misalignment), and the daily timing of activity and sleep (center of gravity and mid-sleep, respectively). We observed that the long off-work periods between each shift create a fast alternation between shortened (mean ± standard deviation, 5h 17min ± 56min) and extended (8h 25min ± 72min) sleep episodes resulting in immanent reductions of sleep debt. Additionally, extensive napping of early chronotypes (up to 3 hours before the night shift) statistically compensated short sleep durations after the night shift. Partial rank correlations showed chronotype-dependent patterns of sleep and activity that were similar to those previously described in 8-h schedules; however, sleep before the day shift did not differ between chronotypes. Our findings indicate that schedules preventing a build-up of chronic sleep debt may reduce detrimental effects of shift work irrespective of shift duration. Prospective studies are needed to further elucidate the relationship between sleep, the circadian system, and health and safety hazards.

Variations in Sleep and Performance by Duty Start Time in Short Haul Operations

NASA Technical Reports Server (NTRS)

Flynn-Evans, Erin

2016-01-01

Prior studies have confirmed that commercial airline pilots experience circadian phase shifts and short sleep duration following travel with layovers in different time zones. Few studies have examined the impact of early and late starts on the sleep and circadian phase of airline pilots who return to their domicile after each duty period. We recruited 44 pilots (4 female) from a short-haul commercial airline to participate in a study examining sleep and circadian phase over four duty schedules (baseline, early starts, mid-day starts, late starts). Each duty schedule was five days long, separated by three rest days. Participants completed the rosters in the same order. Sleep outcomes were estimated using wrist-borne actigraphy (Actiware Software, Respironics, Bend, OR) and daily sleep diaries. Thirteen participants volunteered to collect urine samples for the assessment of 6-sulfatoxymelatonin (aMT6s). Urine samples were collected in four-hourly bins during the day and eight-hourly bins during sleep episodes, for 24 hours immediately following each experimental duty schedule. The aMT6s results were fit to a cosine in order to obtain the acrophase to estimate circadian phase. Univariate statistics were calculated for acrophase changes, schedule start times and sleep times. All statistical analyses were computed using SAS software (Cary, IN).

Improvement of a patient's circadian rhythm sleep disorders by aripiprazole was associated with stabilization of his bipolar illness.

PubMed

Tashiro, Tetsuo

2017-04-01

Splitting of the behavioural activity phase has been found in nocturnal rodents with suprachiasmatic nucleus (SCN) coupling disorder. A similar phenomenon was observed in the sleep phase in the diurnal human discussed here, suggesting that there are so-called evening and morning oscillators in the SCN of humans. The present case suffered from bipolar disorder refractory to various treatments, and various circadian rhythm sleep disorders, such as delayed sleep phase, polyphasic sleep, separation of the sleep bout resembling splitting and circabidian rhythm (48 h), were found during prolonged depressive episodes with hypersomnia. Separation of sleep into evening and morning components and delayed sleep-offset (24.69-h cycle) developed when lowering and stopping the dose of aripiprazole (APZ). However, resumption of APZ improved these symptoms in 2 weeks, accompanied by improvement in the patient's depressive state. Administration of APZ may improve various circadian rhythm sleep disorders, as well as improve and prevent manic-depressive episodes, via augmentation of coupling in the SCN network. © 2017 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

A global quantification of “normal” sleep schedules using smartphone data

PubMed Central

Walch, Olivia J.; Cochran, Amy; Forger, Daniel B.

2016-01-01

The influence of the circadian clock on sleep scheduling has been studied extensively in the laboratory; however, the effects of society on sleep remain largely unquantified. We show how a smartphone app that we have developed, ENTRAIN, accurately collects data on sleep habits around the world. Through mathematical modeling and statistics, we find that social pressures weaken and/or conceal biological drives in the evening, leading individuals to delay their bedtime and shorten their sleep. A country’s average bedtime, but not average wake time, predicts sleep duration. We further show that mathematical models based on controlled laboratory experiments predict qualitative trends in sunrise, sunset, and light level; however, these effects are attenuated in the real world around bedtime. Additionally, we find that women schedule more sleep than men and that users reporting that they are typically exposed to outdoor light go to sleep earlier and sleep more than those reporting indoor light. Finally, we find that age is the primary determinant of sleep timing, and that age plays an important role in the variability of population-level sleep habits. This work better defines and personalizes “normal” sleep, produces hypotheses for future testing in the laboratory, and suggests important ways to counteract the global sleep crisis. PMID:27386531

Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial.

PubMed

Sletten, Tracey L; Magee, Michelle; Murray, Jade M; Gordon, Christopher J; Lovato, Nicole; Kennaway, David J; Gwini, Stella M; Bartlett, Delwyn J; Lockley, Steven W; Lack, Leon C; Grunstein, Ronald R; Rajaratnam, Shantha M W

2018-06-01

Delayed Sleep-Wake Phase Disorder (DSWPD) is characterised by sleep initiation insomnia when attempting sleep at conventional times and difficulty waking at the required time for daytime commitments. Although there are published therapeutic guidelines for the administration of melatonin for DSWPD, to our knowledge, randomised controlled trials are lacking. This trial tested the efficacy of 0.5 mg melatonin, combined with behavioural sleep-wake scheduling, for improving sleep initiation in clinically diagnosed DSWPD patients with a delayed endogenous melatonin rhythm relative to patient-desired (or -required) bedtime (DBT). This randomised, placebo-controlled, double-blind clinical trial was conducted in an Australian outpatient DSWPD population. Following 1-wk baseline, clinically diagnosed DSWPD patients with delayed melatonin rhythm relative to DBT (salivary dim light melatonin onset [DLMO] after or within 30 min before DBT) were randomised to 4-wk treatment with 0.5 mg fast-release melatonin or placebo 1 h before DBT for at least 5 consecutive nights per week. All patients received behavioural sleep-wake scheduling, consisting of bedtime scheduled at DBT. The primary outcome was actigraphic sleep onset time. Secondary outcomes were sleep efficiency in the first third of time in bed (SE T1) on treatment nights, subjective sleep-related daytime impairment (Patient Reported Outcomes Measurement Information System [PROMIS]), PROMIS sleep disturbance, measures of daytime sleepiness, clinician-rated change in illness severity, and DLMO time. Between September 13, 2012 and September 1, 2014, 307 participants were registered; 116 were randomised to treatment (intention-to-treat n = 116; n = 62 males; mean age, 29.0 y). Relative to baseline and compared to placebo, sleep onset occurred 34 min earlier (95% confidence interval [CI] -60 to -8) in the melatonin group. SE T1 increased; PROMIS sleep-related impairment, PROMIS sleep disturbance, insomnia severity, and functional disability decreased; and a greater proportion of patients showed more than minimal clinician-rated improvement following melatonin treatment (52.8%) compared to placebo (24.0%) (P < 0.05). The groups did not differ in the number of nights treatment was taken per protocol. Post-treatment DLMO assessed in a subset of patients (n = 43) was not significantly different between groups. Adverse events included light-headedness, daytime sleepiness, and decreased libido, although rates were similar between treatment groups. The clinical benefits or safety of melatonin with long-term treatment were not assessed, and it remains unknown whether the same treatment regime would benefit patients experiencing DSWPD sleep symptomology without a delay in the endogenous melatonin rhythm. In this study, melatonin treatment 1 h prior to DBT combined with behavioural sleep-wake scheduling was efficacious for improving objective and subjective measures of sleep disturbances and sleep-related impairments in DSWPD patients with delayed circadian phase relative to DBT. Improvements were achieved largely through the sleep-promoting effects of melatonin, combined with behavioural sleep-wake scheduling. This trial was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12612000425897.

Fatigue in U.S. Astronauts Onboard the International Space Station: Environmental factors, Operational Impacts, and Implementation of Countermeasures

NASA Technical Reports Server (NTRS)

Scheuring, R. A.; Moomaw, R. C.; Johnston, S. L.

2015-01-01

Crewmembers have experienced fatigue for reasons similar to military deployments. Astronauts experience psychological stressors such as: heavy workloads, extended duty periods, circadian misalignment, inadequate/ineffective sleep, distracting background noise, unexpected and variable mission schedules, unfavorable thermal control, unusual sleep environment with schedules that impinge on pre-sleep periods.

Best Practices for Fatigue Risk Management in Non-Traditional Shiftwork

NASA Technical Reports Server (NTRS)

Flynn-Evans, Erin E.

2016-01-01

Fatigue risk management programs provide effective tools to mitigate fatigue among shift workers. Although such programs are effective for typical shiftwork scenarios, where individuals of equal skill level can be divided into shifts to cover 24 hour operations, traditional programs are not sufficient for managing sleep loss among individuals with unique skill sets, in occupations where non-traditional schedules are required. Such operations are prevalent at NASA and in other high stress occupations, including among airline pilots, military personnel, and expeditioners. These types of operations require fatigue risk management programs tailored to the specific requirements of the mission. Without appropriately tailored fatigue risk management, such operations can lead to an elevated risk of operational failure, disintegration of teamwork, and increased risk of accidents and incidents. In order to design schedules for such operations, schedule planners must evaluate the impact of a given operation on circadian misalignment, acute sleep loss, chronic sleep loss and sleep inertia. In addition, individual-level factors such as morningness-eveningness preference and sleep disorders should be considered. After the impact of each of these factors has been identified, scheduling teams can design schedules that meet operational requirements, while also minimizing fatigue.

Associations between shift schedule characteristics with sleep, need for recovery, health and performance measures for regular (semi-)continuous 3-shift systems.

PubMed

van de Ven, Hardy A; Brouwer, Sandra; Koolhaas, Wendy; Goudswaard, Anneke; de Looze, Michiel P; Kecklund, Göran; Almansa, Josue; Bültmann, Ute; van der Klink, Jac J L

2016-09-01

In this cross-sectional study associations were examined between eight shift schedule characteristics with shift-specific sleep complaints and need for recovery and generic health and performance measures. It was hypothesized that shift schedule characteristics meeting ergonomic recommendations are associated with better sleep, need for recovery, health and performance. Questionnaire data were collected from 491 shift workers of 18 companies with 9 regular (semi)-continuous shift schedules. The shift schedule characteristics were analyzed separately and combined using multilevel linear regression models. The hypothesis was largely not confirmed. Relatively few associations were found, of which the majority was in the direction as expected. In particular early starts of morning shifts and many consecutive shifts seem to be avoided. The healthy worker effect, limited variation between included schedules and the cross-sectional design might explain the paucity of significant results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Advancing circadian rhythms before eastward flight: a strategy to prevent or reduce jet lag.

PubMed

Eastman, Charmane I; Gazda, Clifford J; Burgess, Helen J; Crowley, Stephanie J; Fogg, Louis F

2005-01-01

To develop a practical pre-eastward flight treatment to advance circadian rhythms as much as possible but not misalign them with sleep. One group had their sleep schedule advanced by 1 hour per day and another by 2 hours per day. Baseline at home, treatment in lab. Young healthy adults (11 men, 15 women) between the ages of 22 and 36 years. Three days of a gradually advancing sleep schedule (1 or 2 hours per day) plus intermittent morning bright light (one-half hour approximately 5000 lux, one-half hour of <60 lux) for 3.5 hours. The dim light melatonin onset was assessed before and after the 3-day treatment. Subjects completed daily sleep logs and symptom questionnaires and wore wrist activity monitors. The dim light melatonin onset advanced more in the 2-hours-per-day group than in the 1-hour-per-day group (median phase advances of 1.9 and 1.4 hours), but the difference between the means (1.8 and 1.5 hours) was not statistically significant. By the third treatment day, circadian rhythms were misaligned relative to the sleep schedule, and subjects had difficulty falling asleep in the 2-hours-per-day group, but this was not the case in the 1-hour-per-day group. Nevertheless, the 2-hours-per-day group did slightly better on the symptom questionnaires. In general, sleep disturbance and other side effects were small. A gradually advancing sleep schedule with intermittent morning bright light can be used to advance circadian rhythms before eastward flight and, thus, theoretically, prevent or reduce subsequent jet lag. Given the morning light treatment used here, advancing the sleep schedule 2 hours per day is not better than advancing it 1 hour per day because it was too fast for the advance in circadian rhythms. A diagram is provided to help the traveler plan a preflight schedule.

Daytime bright light exposure, metabolism, and individual differences in wake and sleep energy expenditure during circadian entrainment and misalignment

PubMed Central

Melanson, Edward L.; Ritchie, Hannah K.; Dear, Tristan B.; Catenacci, Victoria; Shea, Karen; Connick, Elizabeth; Moehlman, Thomas M.; Stothard, Ellen R.; Higgins, Janine; McHill, Andrew W.; Wright, Kenneth P.

2018-01-01

Daytime light exposure has been reported to impact or have no influence on energy metabolism in humans. Further, whether inter-individual differences in wake, sleep, 24 h energy expenditure, and RQ during circadian entrainment and circadian misalignment are stable across repeated 24 h assessments is largely unknown. We present data from two studies: Study 1 of 15 participants (7 females) exposed to three light exposure conditions: continuous typical room ~100 lx warm white light, continuous ~750 lx warm white light, and alternating hourly ~750 lx warm white and blue-enriched white light on three separate days in a randomized order; and Study 2 of 14 participants (8 females) during circadian misalignment induced by a simulated night shift protocol. Participants were healthy, free of medical disorders, medications, and illicit drugs. Participants maintained a consistent 8 h per night sleep schedule for one week as an outpatient prior to the study verified by wrist actigraphy, sleep diaries, and call-ins to a time stamped recorder. Participants consumed an outpatient energy balance research diet for three days prior to the study. The inpatient protocol for both studies consisted of an initial sleep disorder screening night. For study 1, this was followed by three standard days with 16 h scheduled wakefulness and 8 h scheduled nighttime sleep. For Study 2, it was followed by 16 h scheduled wake and 8 h scheduled sleep at habitual bedtime followed by three night shifts with 8 h scheduled daytime sleep. Energy expenditure was measured using whole-room indirect calorimetry. Constant posture bedrest conditions were maintained to control for energy expenditure associated with activity and the baseline energy balance diet was continued with the same exact meals across days to control for thermic effects of food. No significant impact of light exposure was observed on metabolic outcomes in response to daytime light exposure. Inter-individual variability in energy expenditure was systematic and ranged from substantial to almost perfect consistency during both nighttime sleep and circadian misalignment. Findings show robust and stable trait-like individual differences in whole body 24 h, waking, and sleep energy expenditure, 24 h respiratory quotient—an index of a fat and carbohydrate oxidation—during repeated assessments under entrained conditions, and also in 24 h and sleep energy expenditure during repeated days of circadian misalignment. PMID:29876528

Daytime bright light exposure, metabolism, and individual differences in wake and sleep energy expenditure during circadian entrainment and misalignment.

PubMed

Melanson, Edward L; Ritchie, Hannah K; Dear, Tristan B; Catenacci, Victoria; Shea, Karen; Connick, Elizabeth; Moehlman, Thomas M; Stothard, Ellen R; Higgins, Janine; McHill, Andrew W; Wright, Kenneth P

2018-01-01

Daytime light exposure has been reported to impact or have no influence on energy metabolism in humans. Further, whether inter-individual differences in wake, sleep, 24 h energy expenditure, and RQ during circadian entrainment and circadian misalignment are stable across repeated 24 h assessments is largely unknown. We present data from two studies: Study 1 of 15 participants (7 females) exposed to three light exposure conditions: continuous typical room ~100 lx warm white light, continuous ~750 lx warm white light, and alternating hourly ~750 lx warm white and blue-enriched white light on three separate days in a randomized order; and Study 2 of 14 participants (8 females) during circadian misalignment induced by a simulated night shift protocol. Participants were healthy, free of medical disorders, medications, and illicit drugs. Participants maintained a consistent 8 h per night sleep schedule for one week as an outpatient prior to the study verified by wrist actigraphy, sleep diaries, and call-ins to a time stamped recorder. Participants consumed an outpatient energy balance research diet for three days prior to the study. The inpatient protocol for both studies consisted of an initial sleep disorder screening night. For study 1, this was followed by three standard days with 16 h scheduled wakefulness and 8 h scheduled nighttime sleep. For Study 2, it was followed by 16 h scheduled wake and 8 h scheduled sleep at habitual bedtime followed by three night shifts with 8 h scheduled daytime sleep. Energy expenditure was measured using whole-room indirect calorimetry. Constant posture bedrest conditions were maintained to control for energy expenditure associated with activity and the baseline energy balance diet was continued with the same exact meals across days to control for thermic effects of food. No significant impact of light exposure was observed on metabolic outcomes in response to daytime light exposure. Inter-individual variability in energy expenditure was systematic and ranged from substantial to almost perfect consistency during both nighttime sleep and circadian misalignment. Findings show robust and stable trait-like individual differences in whole body 24 h, waking, and sleep energy expenditure, 24 h respiratory quotient-an index of a fat and carbohydrate oxidation-during repeated assessments under entrained conditions, and also in 24 h and sleep energy expenditure during repeated days of circadian misalignment.

Energy-saving framework for passive optical networks with ONU sleep/doze mode.

PubMed

Van, Dung Pham; Valcarenghi, Luca; Dias, Maluge Pubuduni Imali; Kondepu, Koteswararao; Castoldi, Piero; Wong, Elaine

2015-02-09

This paper proposes an energy-saving passive optical network framework (ESPON) that aims to incorporate optical network unit (ONU) sleep/doze mode into dynamic bandwidth allocation (DBA) algorithms to reduce ONU energy consumption. In the ESPON, the optical line terminal (OLT) schedules both downstream (DS) and upstream (US) transmissions in the same slot in an online and dynamic fashion whereas the ONU enters sleep mode outside the slot. The ONU sleep time is maximized based on both DS and US traffic. Moreover, during the slot, the ONU might enter doze mode when only its transmitter is idle to further improve energy efficiency. The scheduling order of data transmission, control message exchange, sleep period, and doze period defines an energy-efficient scheme under the ESPON. Three schemes are designed and evaluated in an extensive FPGA-based evaluation. Results show that whilst all the schemes significantly save ONU energy for different evaluation scenarios, the scheduling order has great impact on their performance. In addition, the ESPON allows for a scheduling order that saves ONU energy independently of the network reach.

Estimating dim light melatonin onset (DLMO) phase in adolescents using summer or school-year sleep/wake schedules.

PubMed

Crowley, Stephanie J; Acebo, Christine; Fallone, Gahan; Carskadon, Mary A

2006-12-01

This analysis examined associations between the salivary dim light melatonin onset (DLMO) phase and self-selected sleep/ wake schedules in groups of children and adolescents during summer vacation and during the school year to determine the degree to which sleep/wake patterns can estimate salivary DLMO phase. Participants slept at home on self-selected schedules for 5 consecutive nights and reported their bedtime and wake-up time via daily telephone messages. Salivary melatonin was sampled in the laboratory on one evening every 30 minutes in dim light (< 50 lux) to determine DLMO phase. Within group bivariate regressions between sleep pattern measures (bedtime, wake-up time, and midsleep time) and DLMO phase were computed. One group, ages 9 to 17 years (mean age = 12.5, SD = 2.3 years, 74 males, 75 females) contributed 149 DLMO phase and sleep/wake pattern measures while on a school year schedule ("school group"). A separate group, ages 9 to 16 years (mean age = 13.1, SD = 1.3 years, 30 males, 29 females) contributed 59 DLMO phase and sleep/wake pattern measures while on a summer schedule ("summer group"). Bedtime, midsleep time, and wake-up time were positively correlated with DLMO phase in both groups. Although all correlation coefficients for the summer group were statistically greater compared to the school group, the regression equations predicted DLMO phase within +/- 1 hour of the measured DLMO phase in approximately 80% for both groups. DLMO phase can be estimated using self-selected sleep/wake patterns during the school year or summer vacation in healthy children and adolescents.

Sleep Disruption Medical Intervention Forecasting (SDMIF) Module for the Integrated Medical Model

NASA Technical Reports Server (NTRS)

Lewandowski, Beth; Brooker, John; Mallis, Melissa; Hursh, Steve; Caldwell, Lynn; Myers, Jerry

2011-01-01

The NASA Integrated Medical Model (IMM) assesses the risk, including likelihood and impact of occurrence, of all credible in-flight medical conditions. Fatigue due to sleep disruption is a condition that could lead to operational errors, potentially resulting in loss of mission or crew. Pharmacological consumables are mitigation strategies used to manage the risks associated with sleep deficits. The likelihood of medical intervention due to sleep disruption was estimated with a well validated sleep model and a Monte Carlo computer simulation in an effort to optimize the quantity of consumables. METHODS: The key components of the model are the mission parameter program, the calculation of sleep intensity and the diagnosis and decision module. The mission parameter program was used to create simulated daily sleep/wake schedules for an ISS increment. The hypothetical schedules included critical events such as dockings and extravehicular activities and included actual sleep time and sleep quality. The schedules were used as inputs to the Sleep, Activity, Fatigue and Task Effectiveness (SAFTE) Model (IBR Inc., Baltimore MD), which calculated sleep intensity. Sleep data from an ISS study was used to relate calculated sleep intensity to the probability of sleep medication use, using a generalized linear model for binomial regression. A human yes/no decision process using a binomial random number was also factored into sleep medication use probability. RESULTS: These probability calculations were repeated 5000 times resulting in an estimate of the most likely amount of sleep aids used during an ISS mission and a 95% confidence interval. CONCLUSIONS: These results were transferred to the parent IMM for further weighting and integration with other medical conditions, to help inform operational decisions. This model is a potential planning tool for ensuring adequate sleep during sleep disrupted periods of a mission.

Sleep Tips: 7 Steps to Better Sleep

MedlinePlus

... turn every night. Consider simple tips for better sleep, from setting a sleep schedule to including physical activity in your daily ... factors that can interfere with a good night's sleep — from work stress and family responsibilities to unexpected ...

A hybrid flowshop scheduling model considering dedicated machines and lot-splitting for the solar cell industry

NASA Astrophysics Data System (ADS)

Wang, Li-Chih; Chen, Yin-Yann; Chen, Tzu-Li; Cheng, Chen-Yang; Chang, Chin-Wei

2014-10-01

This paper studies a solar cell industry scheduling problem, which is similar to traditional hybrid flowshop scheduling (HFS). In a typical HFS problem, the allocation of machine resources for each order should be scheduled in advance. However, the challenge in solar cell manufacturing is the number of machines that can be adjusted dynamically to complete the job. An optimal production scheduling model is developed to explore these issues, considering the practical characteristics, such as hybrid flowshop, parallel machine system, dedicated machines, sequence independent job setup times and sequence dependent job setup times. The objective of this model is to minimise the makespan and to decide the processing sequence of the orders/lots in each stage, lot-splitting decisions for the orders and the number of machines used to satisfy the demands in each stage. From the experimental results, lot-splitting has significant effect on shortening the makespan, and the improvement effect is influenced by the processing time and the setup time of orders. Therefore, the threshold point to improve the makespan can be identified. In addition, the model also indicates that more lot-splitting approaches, that is, the flexibility of allocating orders/lots to machines is larger, will result in a better scheduling performance.

Baby Naps: Daytime Sleep Tips

MedlinePlus

... but the process of getting your baby to sleep during the day can be just the opposite. ... It takes awhile for newborns to develop a sleep schedule. During the first month, babies usually sleep ...

Too Tired To Learn.

ERIC Educational Resources Information Center

Wilkoff, Will

2002-01-01

Pediatrician offers principals four suggestions to help alleviate sleep deprivation in children: Include sleep in the curriculum, raise parental awareness, consider the child's sleep habits in evaluations, and create "sleep-friendly" policies and schedules. (PKP)

Dynamic Sensor Networks

DTIC Science & Technology

2004-03-01

turned off. SLEEP Set the timer for 30 seconds before scheduled transmit time, then sleep the processor. WAKE When timer trips, power up the processor...slots where none of its neighbors are schedule to transmit. This allows the sensor nodes to perform a simple power man- agement scheme that puts the...routing This simple case study highlights the following crucial observation: optimal traffic scheduling in energy constrained networks requires future

Prioritizing Sleep Health: Public Health Policy Recommendations.

PubMed

Barnes, Christopher M; Drake, Christopher L

2015-11-01

The schedules that Americans live by are not consistent with healthy sleep patterns. In addition, poor access to educational and treatment aids for sleep leaves people engaging in behavior that is harmful to sleep and forgoing treatment for sleep disorders. This has created a sleep crisis that is a public health issue with broad implications for cognitive outcomes, mental health, physical health, work performance, and safety. New public policies should be formulated to address these issues. We draw from the scientific literature to recommend the following: establishing national standards for middle and high school start times that are later in the day, stronger regulation of work hours and schedules, eliminating daylight saving time, educating the public regarding the impact of electronic media on sleep, and improving access to ambulatory in-home diagnostic testing for sleep disorders. © The Author(s) 2015.

How shift scheduling practices contribute to fatigue amongst freight rail operating employees: Findings from Canadian accident investigations.

PubMed

Rudin-Brown, Christina M; Harris, Sarah; Rosberg, Ari

2018-02-01

Canada's freight rail system moves 70% of the country's surface goods and almost half of all exports (RAC, 2016). These include dangerous goods. Anonymous survey of freight rail operating employees conducted by the Teamsters Canada Rail Conference (TCRC, 2014) revealed that many do not report getting enough sleep because of their work schedules, and that fatigue may be affecting their performance at work. Besides general impairments in attention and cognitive functioning, fatigue in railway operating employees slows reaction time to safety alarms and impairs conformance to train operating requirements. Shift scheduling practices can contribute to sleep-related fatigue by restricting sleep opportunities, requiring extended periods of wakefulness and by disrupting daily (circadian) rhythms. The primary goal of accident investigation is to identify causal and contributing factors so that similar occurrences can be prevented. A database search of Transportation Safety Board (TSB) rail investigation reports published in the 21-year period from 1995 to 2015 identified 18 that cited sleep-related fatigue of freight rail operating employees as a causal, contributing, or risk finding. This number represents about 20% of TSB rail investigations from the same period in which a human factors aspect of freight train activities was a primary cause. Exploration of accident themes suggests that management of fatigue and shift scheduling in the freight rail industry is a complex issue that is often not conducive to employee circadian rhythms and sleep requirements. It also suggests that current shift scheduling and fatigue management practices may be insufficient to mitigate the associated safety risk. Railway fatigue management systems that are based on the principles of modern sleep science are needed to improve scheduling practices and mitigate the ongoing safety risk. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Sleep, the Athlete, and Performance.

ERIC Educational Resources Information Center

Walters, Peter Hudson

2002-01-01

Presents information to help athletic coaches and trainers gain a better understanding of what happens during sleep and how sleep can affect performance, outlining three practical suggestions for helping athletes improve their sleep quality (identify and obtain the amount of sleep one needs, keep a regular sleep schedule, and create an optimal…

Rapid counterclockwise shift rotation in air traffic control: effects on sleep and night work.

PubMed

Signal, T Leigh; Gander, Philippa H

2007-09-01

In Air Traffic Control, counterclockwise rapidly rotating shift schedules are often employed but may result in significant sleep loss. This has potential consequences for performance, particularly if a night shift is worked. As part of a large-scale field study, the pattern of sleep across a 4-d counterclockwise, rapidly rotating schedule (afternoon, day, morning, night shift) was documented and relationships between prior sleep and performance during the night shift were investigated. There were 28 controllers who completed 4 periods of data collection which included 2 d before and 2 d after a 4-d shift cycle. Sleep was recorded using an actigraph and sleep diary, and performance on each night shift was measured three times using the Psychomotor Vigilance Task. Across the work week, sleep duration decreased largely due to earlier rise times associated with shift start times moving backward. In the short turn-around between the morning and night shift, 90% of controllers slept for an average of 2.2 h. Improved performance on the night shift was related only to longer periods of sleep the night prior. This study demonstrates that a 4-d counterclockwise, rapidly rotating schedule results in a progressive reduction in sleep and consequently the rapid accumulation of a sleep debt. To help maintain their performance on the night shift, it is recommended that controllers attempt to obtain at least 6 h sleep the night before a night shift. It is also recommended that ATC providers educate their workforce about this issue.

[Work schedules in the Hungarian health care system and the sleep quality of nurses].

PubMed

Fusz, Katalin; Pakai, Annamária; Kívés, Zsuzsanna; Szunomár, Szilvia; Regős, Annamária; Oláh, András

2016-03-06

One way of ensuring the continuity of health care is the shift work, which is burdensome and it can lead to sleep disturbances. The aim of the study was to measure the typical Hungarian nursing shift systems in hospitals, to analyse the causes of irregular work schedules, and to compare the sleep quality of nurses in different work schedules. 236 head nurses filled out the national online survey, and 217 nurses in clinics of the University of Pécs filled the Hungarian version of Bergen Shift Work Sleep Questionnaire. The head nurses provided data of 8697 nurses's schedules. 51.89% of nurses work in flexible shift system. 1944 employees work in regular shift system, most of them in the following order: 12-hour day shift and 12-hour night shift, followed by a one- or two-day rest. Where there is no system of shifts, the most frequent causes are the needs of nurses and the nurse shortage. Nurses who are working in irregular shift system had worse sleep quality than nurses who are working in flexible and regular shift system (p = 0.044). It would be helpful if the least burdensome shift system could be established.

Submarine watch schedules: underway evaluation of rotating (contemporary) and compressed (alternative) schedules.

PubMed

Duplessis, C A; Miller, J C; Crepeau, L J; Osborn, C M; Dyche, J

2007-01-01

With a desire to increase health, cognitive performance effectiveness, and quality of life for submarine watch-standers underway, we performed an evaluation comparing an alternative, compressed-work (ALT) schedule, designed to enhance circadian rhythm entrainment and sleep hygiene, to the contemporary submarine (SUB) forward rotating schedule, aboard the ballistic-missile submarine, USS Henry M. Jackson (SSBN-730 Gold). We assessed a compressed close-6 watch-schedule ("ALT") relative to the existing backward rotating 6-hr on, 12-hr off 18-hr watch schedule ("SUB") employed underway aboard submarines. We monitored 40 subjects' sleep, and temperature and salivary cortisol from 10 of the 40 for approximately two weeks on each respective schedule underway. The cortisol cosinor mesors (midline estimating statistic of rhythm), and amplitudes did not differ significantly between conditions. The temperature cosinor mesors, and the cosinor amplitude were not significantly different, while the cosine curve fit accounted for significantly more variance in the ALT condition than in the SUB condition. The SUB schedule garnered significantly more sleep (7.1 +/- 0.2 hours) than that of the ALTMID schedule (6.3 +/- 0.3 hours). Surveys revealed that 52% of respondents preferred the SUB schedule, 15% preferred the ALT, and 33% were either indifferent or submitted uninterpretable surveys. The ALT schedule was not superior to the existing SUB schedule by physiological or subjective measures and was incompatible to accommodating operational constraints.

Sleep and need for recovery in shift workers: do chronotype and age matter?

PubMed

van de Ven, Hardy A; van der Klink, Jac J L; Vetter, Céline; Roenneberg, Till; Gordijn, Marijke; Koolhaas, Wendy; de Looze, Michiel P; Brouwer, Sandra; Bültmann, Ute

2016-01-01

This study examined associations of chronotype and age with shift-specific assessments of main sleep duration, sleep quality and need for recovery in a cross-sectional study among N = 261 industrial shift workers (96.6% male). Logistic regression analyses were used, adjusted for gender, lifestyle, health, nap behaviour, season of assessment and shift schedule. Shift workers with latest versus earliest chronotype reported a shorter sleep duration (OR 11.68, 95% CI 3.31-41.17) and more awakenings complaints (OR 4.84, 95% CI 4.45-11.92) during morning shift periods. No associations were found between chronotype, sleep and need for recovery during evening and night shift periods. For age, no associations were found with any of the shift-specific outcome measures. The results stress the importance of including the concept of chronotype in shift work research and scheduling beyond the concept of age. Longitudinal research using shift-specific assessments of sleep and need for recovery are needed to confirm these results. Chronotype seems to better explain individual differences in sleep than age. In view of ageing societies, it might therefore be worthwhile to further examine the application of chronotype for individualised shift work schedules to facilitate healthy and sustainable employment.

Validation of FAST Model Sleep Estimates with Actigraph Measured Sleep in Locomotive Engineers

DOT National Transportation Integrated Search

2012-04-01

This report presents the results of a study to validate the AutoSleep sleep prediction algorithm, which is a component of the Fatigue Avoidance Scheduling Tool (FAST). Researchers collected work and sleep data from 41 locomotive engineers by using ac...

Middle school start times: the importance of a good night's sleep for young adolescents.

PubMed

Wolfson, Amy R; Spaulding, Noah L; Dandrow, Craig; Baroni, Elizabeth M

2007-01-01

With the onset of adolescence, teenagers require 9.2 hr of sleep and experience a delay in the timing of sleep. In the "real world" with early school start times, however, they report less sleep, striking differences between their school-weekend sleep schedules, and significant daytime sleepiness. Prior studies demonstrated that high schoolers with later school starts do not further delay bedtime but obtain more sleep due to later wake times. This study examined sleep-wake patterns of young adolescents attending urban, public middle schools with early (7:15 a.m.) versus late (8:37 a.m.) start times. Students (N = 205) were assessed at 2 time periods. Students at the late-starting school reported waking up over 1 hr later on school mornings and obtaining 50 min more sleep each night, less sleepiness, and fewer tardies than students at the early school. All students reported similar school-night bedtime, sleep hygiene practices, and weekend sleep schedules.

Sleep/wake patterns and circadian typology in preschool children based on standardized parental self-reports.

PubMed

Doi, Yuriko; Ishihara, Kaneyoshi; Uchiyama, Makoto

2014-04-01

We studied the sleep/wake patterns and circadian typology of Japanese preschool children living in the Tokyo metropolitan area (193 boys and 190 girls, 4-6 years of age) from June to July 2012 based on a standardized parental self-reporting questionnaire. Our major findings are as follows: (1) sleep/wake timing was delayed, and the duration of nocturnal sleep (sleep period as well as time in bed) increased from that on scheduled days (weekdays) to that on free days (weekends) for all ages. (2) The duration of daily sleep (24 h), including daytime nap, was longer for 4-year-old children compared with that in 5- to 6-year-old children, but not significantly different between scheduled and free days within each age group. (3) The distribution of chronotypes was 36.3% for morning (M)-type, 48.8% for neither (N)-type and 11.2% for evening (E)-type, and this distribution was independent of sex or age. (4) Sleep/wake timing delays were observed from M-type and N-type to E-type during scheduled and free days. (5) The duration of nocturnal sleep decreased but increased for 24-h sleep time from M-type and N-type to E-type on scheduled days. (6) Sleep durations did not differ among chronotypes on free days. (7) Chronotypes were associated with parents' diurnal preferences, mealtimes and attendance at kindergartens or childcare centers but not with sex, age, season of birth, exposure to multimedia or exposure to morning sunlight in their bedrooms. When these results were compared with those for older children and adolescents, similar sleep/wake patterns and circadian typology were observed, although to a lesser degree, in children as young as 4-6 years of age. Napping may compensate, in part, for an accumulated weekday sleep deficit. The distribution of chronotypes was associated with differences in sleep/wake timing and duration and was influenced by the parents' diurnal preferences and lifestyles. Further research on preschool children is required to investigate whether circadian typology affects their behavioral, emotional and cognitive development.

Effect of reducing interns' weekly work hours on sleep and attentional failures.

PubMed

Lockley, Steven W; Cronin, John W; Evans, Erin E; Cade, Brian E; Lee, Clark J; Landrigan, Christopher P; Rothschild, Jeffrey M; Katz, Joel T; Lilly, Craig M; Stone, Peter H; Aeschbach, Daniel; Czeisler, Charles A

2004-10-28

Knowledge of the physiological effects of extended (24 hours or more) work shifts in postgraduate medical training is limited. We aimed to quantify work hours, sleep, and attentional failures among first-year residents (postgraduate year 1) during a traditional rotation schedule that included extended work shifts and during an intervention schedule that limited scheduled work hours to 16 or fewer consecutive hours. Twenty interns were studied during two three-week rotations in intensive care units, each during both the traditional and the intervention schedule. Subjects completed daily sleep logs that were validated with regular weekly episodes (72 to 96 hours) of continuous polysomnography (r=0.94) and work logs that were validated by means of direct observation by study staff (r=0.98). Seventeen of 20 interns worked more than 80 hours per week during the traditional schedule (mean, 84.9; range, 74.2 to 92.1). All interns worked less than 80 hours per week during the intervention schedule (mean, 65.4; range, 57.6 to 76.3). On average, interns worked 19.5 hours per week less (P<0.001), slept 5.8 hours per week more (P<0.001), slept more in the 24 hours preceding each working hour (P<0.001), and had less than half the rate of attentional failures while working during on-call nights (P=0.02) on the intervention schedule as compared with the traditional schedule. Eliminating interns' extended work shifts in an intensive care unit significantly increased sleep and decreased attentional failures during night work hours. Copyright 2004 Massachusetts Medical Society.

Distributed Sleep Scheduling in Wireless Sensor Networks via Fractional Domatic Partitioning

NASA Astrophysics Data System (ADS)

Schumacher, André; Haanpää, Harri

We consider setting up sleep scheduling in sensor networks. We formulate the problem as an instance of the fractional domatic partition problem and obtain a distributed approximation algorithm by applying linear programming approximation techniques. Our algorithm is an application of the Garg-Könemann (GK) scheme that requires solving an instance of the minimum weight dominating set (MWDS) problem as a subroutine. Our two main contributions are a distributed implementation of the GK scheme for the sleep-scheduling problem and a novel asynchronous distributed algorithm for approximating MWDS based on a primal-dual analysis of Chvátal's set-cover algorithm. We evaluate our algorithm with ns2 simulations.

Sleep, performance, circadian rhythms, and light-dark cycles during two space shuttle flights

NASA Technical Reports Server (NTRS)

Dijk, D. J.; Neri, D. F.; Wyatt, J. K.; Ronda, J. M.; Riel, E.; Ritz-De Cecco, A.; Hughes, R. J.; Elliott, A. R.; Prisk, G. K.; West, J. B.;

Caffeine: sleep and daytime sleepiness.

PubMed

Roehrs, Timothy; Roth, Thomas

2008-04-01

Caffeine is one of the most widely consumed psychoactive substances and it has profound effects on sleep and wake function. Laboratory studies have documented its sleep-disruptive effects. It clearly enhances alertness and performance in studies with explicit sleep deprivation, restriction, or circadian sleep schedule reversals. But, under conditions of habitual sleep the evidence indicates that caffeine, rather then enhancing performance, is merely restoring performance degraded by sleepiness. The sleepiness and degraded function may be due to basal sleep insufficiency, circadian sleep schedule reversals, rebound sleepiness, and/or a withdrawal syndrome after the acute, over-night, caffeine discontinuation typical of most studies. Studies have shown that caffeine dependence develops at relatively low daily doses and after short periods of regular daily use. Large sample and population-based studies indicate that regular daily dietary caffeine intake is associated with disturbed sleep and associated daytime sleepiness. Further, children and adolescents, while reporting lower daily, weight-corrected caffeine intake, similarly experience sleep disturbance and daytime sleepiness associated with their caffeine use. The risks to sleep and alertness of regular caffeine use are greatly underestimated by both the general population and physicians.

Energy-saving scheme based on downstream packet scheduling in ethernet passive optical networks

NASA Astrophysics Data System (ADS)

Zhang, Lincong; Liu, Yejun; Guo, Lei; Gong, Xiaoxue

2013-03-01

With increasing network sizes, the energy consumption of Passive Optical Networks (PONs) has grown significantly. Therefore, it is important to design effective energy-saving schemes in PONs. Generally, energy-saving schemes have focused on sleeping the low-loaded Optical Network Units (ONUs), which tends to bring large packet delays. Further, the traditional ONU sleep modes are not capable of sleeping the transmitter and receiver independently, though they are not required to transmit or receive packets. Clearly, this approach contributes to wasted energy. Thus, in this paper, we propose an Energy-Saving scheme that is based on downstream Packet Scheduling (ESPS) in Ethernet PON (EPON). First, we design both an algorithm and a rule for downstream packet scheduling at the inter- and intra-ONU levels, respectively, to reduce the downstream packet delay. After that, we propose a hybrid sleep mode that contains not only ONU deep sleep mode but also independent sleep modes for the transmitter and the receiver. This ensures that the energy consumed by the ONUs is minimal. To realize the hybrid sleep mode, a modified GATE control message is designed that involves 10 time points for sleep processes. In ESPS, the 10 time points are calculated according to the allocated bandwidths in both the upstream and the downstream. The simulation results show that ESPS outperforms traditional Upstream Centric Scheduling (UCS) scheme in terms of energy consumption and the average delay for both real-time and non-real-time packets downstream. The simulation results also show that the average energy consumption of each ONU in larger-sized networks is less than that in smaller-sized networks; hence, our ESPS is better suited for larger-sized networks.

Sleep, Circadian Rhythms, and Performance During Space Shuttle Missions

NASA Technical Reports Server (NTRS)

Neri, David F.; Czeisler, Charles A.; Dijk, Derk-Jan; Wyatt, James K.; Ronda, Joseph M.; Hughes, Rod J.

2003-01-01

Sleep and circadian rhythms may be disturbed during spaceflight, and these disturbances can affect crewmembers' performance during waking hours. The mechanisms underlying sleep and circadian rhythm disturbances in space are not well understood, and effective countermeasures are not yet available. We investigated sleep, circadian rhythms, cognitive performance, and light-dark cycles in five astronauts prior to, during, and after the 16-day STS-90 mission and the IO-day STS-95 mission. The efficacy of low-dose, alternative-night, oral melatonin administration as a countermeasure for sleep disturbances was evaluated. During these missions, scheduled rest activity cycles were 20-35 minutes shorter than 24 hours. Light levels on the middeck and in the Spacelab were very low; whereas on the flight deck (which has several windows), they were highly variable. Circadian rhythm abnormalities were observed. During the second half of the missions, the rhythm of urinary cortisol appeared to be delayed relative to the sleep-wake schedule. Performance during wakefulness was impaired. Astronauts slept only about 6.5 hours per day, and subjective sleep quality was lower in space. No beneficial effects of melatonin (0.3 mg administered prior to sleep episodes on alternate nights) were observed. A surprising finding was a marked increase in rapid eye movement (REM) sleep upon return to Earth. We conclude that these Space Shuttle missions were associated with circadian rhythm disturbances, sleep loss, decrements in neurobehavioral performance, and alterations in REM sleep homeostasis. Shorter than 24-hour rest-activity schedules and exposure to light-dark cycles inadequate for optimal circadian synchronization may have contributed to these disturbances.

Unit Specific Crew Rest Strategies: Phase 1 Evaluation of the 1/212th Aviation Battalion during Shiftwork Transitions

DTIC Science & Technology

1994-01-01

but do not provide strategies or specific schedules of crew rest tailored to the- unit’s specific mission demands, environmental conditions, and...and the impact of mission driven work schedules and environmental conditions on crew rest quality. Phase II provides rhythms, sleep/wake cycles...shiftwork schedules , and methods for regulating the body’s biological clock to prevent sleep loss during characteristic mission. This report contains a

Causes and consequences of sleepiness among college students.

PubMed

Hershner, Shelley D; Chervin, Ronald D

2014-01-01

Daytime sleepiness, sleep deprivation, and irregular sleep schedules are highly prevalent among college students, as 50% report daytime sleepiness and 70% attain insufficient sleep. The consequences of sleep deprivation and daytime sleepiness are especially problematic to college students and can result in lower grade point averages, increased risk of academic failure, compromised learning, impaired mood, and increased risk of motor vehicle accidents. This article reviews the current prevalence of sleepiness and sleep deprivation among college students, contributing factors for sleep deprivation, and the role of sleep in learning and memory. The impact of sleep and sleep disorders on academics, grade point average, driving, and mood will be examined. Most importantly, effective and viable interventions to decrease sleepiness and sleep deprivation through sleep education classes, online programs, encouragement of naps, and adjustment of class time will be reviewed. This paper highlights that addressing sleep issues, which are not often considered as a risk factor for depression and academic failure, should be encouraged. Promotion of university and college policies and class schedules that encourage healthy and adequate sleep could have a significant impact on the sleep, learning, and health of college students. Future research to investigate effective and feasible interventions, which disseminate both sleep knowledge and encouragement of healthy sleep habits to college students in a time and cost effective manner, is a priority.

An approach to understanding sleep and depressed mood in adolescents: person-centred sleep classification.

PubMed

Shochat, Tamar; Barker, David H; Sharkey, Katherine M; Van Reen, Eliza; Roane, Brandy M; Carskadon, Mary A

2017-12-01

Depressive mood in youth has been associated with distinct sleep dimensions, such as timing, duration and quality. To identify discrete sleep phenotypes, we applied person-centred analysis (latent class mixture models) based on self-reported sleep patterns and quality, and examined associations between phenotypes and mood in high-school seniors. Students (n = 1451; mean age = 18.4 ± 0.3 years; 648 M) completed a survey near the end of high-school. Indicators used for classification included school night bed- and rise-times, differences between non-school night and school night bed- and rise-times, sleep-onset latency, number of awakenings, naps, and sleep quality and disturbance. Mood was measured using the total score on the Center for Epidemiologic Studies-Depression Scale. One-way anova tested differences between phenotype for mood. Fit indexes were split between 3-, 4- and 5-phenotype solutions. For all solutions, between phenotype differences were shown for all indicators: bedtime showed the largest difference; thus, classes were labelled from earliest to latest bedtime as 'A' (n = 751), 'B' (n = 428) and 'C' (n = 272) in the 3-class solution. Class B showed the lowest sleep disturbances and remained stable, whereas classes C and A each split in the 4- and 5-class solutions, respectively. Associations with mood were consistent, albeit small, with class B showing the lowest scores. Person-centred analysis identified sleep phenotypes that differed in mood, such that those with the fewest depressive symptoms had moderate sleep timing, shorter sleep-onset latencies and fewer arousals. Sleep characteristics in these groups may add to our understanding of how sleep and depressed mood associate in teens. © 2017 European Sleep Research Society.

Sleep Duration, Schedule and Quality among Urban Chinese Children and Adolescents: Associations with Routine After-School Activities

PubMed Central

Jiang, Xiaoxiao; Hardy, Louise L.; Baur, Louise A.; Ding, Ding; Wang, Ling; Shi, Huijing

2015-01-01

Background With rapid urbanization accompanied by lifestyle changes, children and adolescents living in metropolitan areas are faced with many time use choices that compete with sleep. This study reports on the sleep hygiene of urban Chinese school students, and investigates the relationship between habitual after-school activities and sleep duration, schedule and quality on a regular school day. Methods Cross-sectional, school-based survey of school children (Grades 4–8) living in Shanghai, China, conducted in 2011. Self-reported data were collected on students’ sleep duration and timing, sleep quality, habitual after-school activities (i.e. homework, leisure-time physical activity, recreational screen time and school commuting time), and potential correlates. Results Mean sleep duration of this sample (mean age: 11.5-years; 48.6% girls) was 9 hours. Nearly 30% of students reported daytime tiredness. On school nights, girls slept less (p<0.001) and went to bed later (p<0.001), a sex difference that was more pronounced in older students. Age by sex interactions were observed for both sleep duration (p=0.005) and bedtime (p=0.002). Prolonged time spent on homework and mobile phone playing was related to shorter sleep duration and later bedtime. Adjusting for all other factors, with each additional hour of mobile phone playing, the odds of daytime tiredness and having difficulty maintaining sleep increased by 30% and 27% among secondary students, respectively. Conclusion There are sex differences in sleep duration, schedule and quality. Habitual activities had small but significant associations with sleep hygiene outcomes especially among secondary school students. Intervention strategies such as limiting children’s use of electronic screen devices after school are implicated. PMID:25611973

Adaptive critics for dynamic optimization.

PubMed

Kulkarni, Raghavendra V; Venayagamoorthy, Ganesh Kumar

2010-06-01

A novel action-dependent adaptive critic design (ACD) is developed for dynamic optimization. The proposed combination of a particle swarm optimization-based actor and a neural network critic is demonstrated through dynamic sleep scheduling of wireless sensor motes for wildlife monitoring. The objective of the sleep scheduler is to dynamically adapt the sleep duration to node's battery capacity and movement pattern of animals in its environment in order to obtain snapshots of the animal on its trajectory uniformly. Simulation results show that the sleep time of the node determined by the actor critic yields superior quality of sensory data acquisition and enhanced node longevity. Copyright 2010 Elsevier Ltd. All rights reserved.

Sleep loss and accidents--work hours, life style, and sleep pathology.

PubMed

Akerstedt, Torbjörn; Philip, Pierre; Capelli, Aurore; Kecklund, Göran

2011-01-01

A very important outcome of reduced sleep is accidents. The present chapter will attempt to bring together some of the present knowledge in this area. We will focus on the driving situation, for which the evidence of the link between sleep loss and accidents is quite well established, but we will also bring up working life in general where evidence is more sparse. It should be emphasized that reduced sleep as a cause of accidents implies that the mediating factor is sleepiness (or fatigue). This link is discussed elsewhere in this volume, but here we will bring in sleepiness (subjective or physiological) as an explanatory factor of accidents. Another central observation is that many real life accident studies do not link accidents to reduced sleep, but infer reduced sleep and/or sleepiness from the context, like, for example, from work schedules, life styles, or sleep pathology. Reduced sleep is mainly due to suboptimal work schedules (or to a suboptimal life style) or to sleep pathology. We have divided the present chapter into two areas. Copyright © 2011 Elsevier B.V. All rights reserved.

Day and night shift schedules are associated with lower sleep quality in Evening-types.

PubMed

Martin, Jeanne Sophie; Laberge, Luc; Sasseville, Alexandre; Bérubé, Marilie; Alain, Samuel; Houle, Jérôme; Hébert, Marc

2015-06-01

Eveningness has been suggested as a facilitating factor in adaptation to shift work, with several studies reporting evening chronotypes (E-types) as better sleepers when on night shifts. Conversely, eveningness has been associated with more sleep complaints during day shifts. However, sleep during day shifts has received limited attention in previous studies assessing chronotypes in shift workers. Environmental light exposure has also been reported to differ between chronotypes in day workers. Activity is also known to provide temporal input to the circadian clock. Therefore, the aim of this study was to compare objective sleep, light exposure and activity levels between chronotypes, both during the night and day shifts. Thirty-nine patrol police patrol officers working on a fast rotating shift schedule (mean age ± SD: 28.9 ± 3.2 yrs; 28 males) participated in this study. All subjects completed the Morningness-Eveningness Questionnaire (MEQ). Sleep and activity were monitored with actigraphy (Actiwatch-L; Mini-Mitter/Respironics, Bend, OR) for four consecutive night shifts and four consecutive day shifts (night work schedule: 00:00 h-07:00 h; day work schedule: 07:00 h-15:00 h). Sleep and activity parameters were calculated with Actiware software. MEQ scores ranged from 26 to 56; no subject was categorized as Morning-type. E-types (n = 13) showed significantly lower sleep efficiency, longer snooze time and spent more time awake after sleep onset than Intermediate-types (I-types, n = 26) for both the night and day shifts. E-types also exhibited shorter and more numerous sleep bouts. Furthermore, when napping was taken into account, E-types had shorter total sleep duration than I-types during the day shifts. E-types were more active during the first hours of their night shift when compared to I-types. Also, all participants spent more time active and had higher amount of activity per minute during day shifts when compared to night shifts. No difference was found regarding light exposure between chronotypes. In conclusion, sleep parameters revealed poorer sleep quality in E-types for both the night and day shifts. These differences could not be explained by sleep opportunity, light exposure or activity levels. This study challenges the notion that E-types adapt better to night shifts. Further studies must verify whether E-types exhibit lower sleep quality than Morning-types.

Healthy Sleep Habits

MedlinePlus

... effective long-term treatment for people with chronic insomnia . CBT can help you address the thoughts and behaviors that prevent you from sleeping well. It also includes techniques for stress reduction, relaxation and sleep schedule management. If you ...

Extended workdays: Effects of 8-hour and 12-hour rotating shift schedules on test performance, subjective alertness, sleep patterns, and psychological variables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosa, R.R.; Colligan, M.J.; Lewis, P.

1986-06-01

A newly instituted 3 to 4 day/12-hr rotating shift schedule was compared to the previous 5 to 7 day/8-hr schedule using standard laboratory-type measures of performance and alertness, and a questionnaire on sleep patterns and other personal habits. After seven months adaptation to the new schedule, a preliminary analysis indicates that there were some decrements in alertness, reductions in sleep, and disruptions of other personal activities during 12-hr workdays. Gastro-intestinal state improved during night shift, however, and increases in self-reported stress were reduced by the shortened workweek. These results are discussed in terms of trade-offs between longer workdays and shortermore » workweeks. It is emphasized that at this time no determination can be made of the extent of risk associated with these changes in alertness.« less

Distributed Signal Processing in Wireless Sensor Networks

DTIC Science & Technology

2005-08-01

in sensor networks. Previous endeavors focused on how to schedule trackers to go to sleep or to wake up trackers based on detection outcomes. On the...one hand, all nodes wake up according to a predefined schedule so that only involved nodes are kept active for the exact duration of a task execution...Recently a new MAC - S-MAC [70] has been proposed, and it enables nodes to sleep not only for a scheduled period, but also for other periods for which

The impact of training schedules on the sleep and fatigue of elite athletes.

PubMed

Sargent, Charli; Lastella, Michele; Halson, Shona L; Roach, Gregory D

2014-12-01

In any sport, successful performance requires a planned approach to training and recovery. While sleep is recognized as an essential component of this approach, the amount and quality of sleep routinely obtained by elite athletes has not been systematically evaluated. Data were collected from 70 nationally ranked athletes from seven different sports. Athletes wore wrist activity monitors and completed self-report sleep/training diaries for 2 weeks during normal training. The athletes also recorded their fatigue level prior to each training session using a 7-point scale. On average, the athletes spent 08:18 ± 01:12 h in bed, fell asleep at 23:06 ± 01:12 h, woke at 6:48 ± 01:30 h and obtained 06:30 ± 01:24 h of sleep per night. There was a marked difference in the athletes' sleep/wake behaviour on training days and rest days. Linear mixed model analyses revealed that on nights prior to training days, time spent in bed was significantly shorter (p = 0.001), sleep onset and offset times were significantly earlier (p < 0.001) and the amount of sleep obtained was significantly less (p = 0.001), than on nights prior to rest days. Moreover, there was a significant effect of sleep duration on pre-training fatigue levels (p ≤ 0.01). Specifically, shorter sleep durations were associated with higher levels of pre-training fatigue. Taken together, these findings suggest that the amount of sleep an elite athlete obtains is dictated by their training schedule. In particular, early morning starts reduce sleep duration and increase pre-training fatigue levels. When designing schedules, coaches should be aware of the implications of the timing of training sessions for sleep and fatigue. In cases where early morning starts are unavoidable, countermeasures for minimizing sleep loss - such as strategic napping during the day and correct sleep hygiene practices at night - should be considered.

MIP models and hybrid algorithms for simultaneous job splitting and scheduling on unrelated parallel machines.

PubMed

Eroglu, Duygu Yilmaz; Ozmutlu, H Cenk

2014-01-01

We developed mixed integer programming (MIP) models and hybrid genetic-local search algorithms for the scheduling problem of unrelated parallel machines with job sequence and machine-dependent setup times and with job splitting property. The first contribution of this paper is to introduce novel algorithms which make splitting and scheduling simultaneously with variable number of subjobs. We proposed simple chromosome structure which is constituted by random key numbers in hybrid genetic-local search algorithm (GAspLA). Random key numbers are used frequently in genetic algorithms, but it creates additional difficulty when hybrid factors in local search are implemented. We developed algorithms that satisfy the adaptation of results of local search into the genetic algorithms with minimum relocation operation of genes' random key numbers. This is the second contribution of the paper. The third contribution of this paper is three developed new MIP models which are making splitting and scheduling simultaneously. The fourth contribution of this paper is implementation of the GAspLAMIP. This implementation let us verify the optimality of GAspLA for the studied combinations. The proposed methods are tested on a set of problems taken from the literature and the results validate the effectiveness of the proposed algorithms.

The Nature of and Behavioral Treatment of Sleep Problems in Youth with Bipolar Disorder

ERIC Educational Resources Information Center

Schwartz, Lisa A.; Feeny, Norah C.

2007-01-01

Bipolar spectrum disorders (BP) occur in up to 1% of youth and are associated with significant impairment. Individuals with BP are often characterized by a decreased need for sleep or dysregulated sleep-wake schedules. For children, such sleep problems often relate to impairment in school and social functioning. Thus, sleep is an especially…

National Sleep Foundation

MedlinePlus

... a healthy sleep schedule boost performance during a game, but it could also protect kids from getting ... your kids up at night? These are 4 key ways to wean them off their digital devices before bed so they can sleep more ...

Holiday and School-Term Sleep Patterns of Australian Adolescents

ERIC Educational Resources Information Center

Warner, Suzanne; Murray, Greg; Meyer, Denny

2008-01-01

The holiday and school-term sleep patterns of 310 Australian senior school students were surveyed in a longitudinal study, along with self-reported sleep quality, mood, daytime functioning, grades and circadian preference. Evidence was found that with the impact of school schedule, students accrued a significant sleep debt, obtaining insufficient…

Causes and consequences of sleepiness among college students

PubMed Central

Hershner, Shelley D; Chervin, Ronald D

2014-01-01

Daytime sleepiness, sleep deprivation, and irregular sleep schedules are highly prevalent among college students, as 50% report daytime sleepiness and 70% attain insufficient sleep. The consequences of sleep deprivation and daytime sleepiness are especially problematic to college students and can result in lower grade point averages, increased risk of academic failure, compromised learning, impaired mood, and increased risk of motor vehicle accidents. This article reviews the current prevalence of sleepiness and sleep deprivation among college students, contributing factors for sleep deprivation, and the role of sleep in learning and memory. The impact of sleep and sleep disorders on academics, grade point average, driving, and mood will be examined. Most importantly, effective and viable interventions to decrease sleepiness and sleep deprivation through sleep education classes, online programs, encouragement of naps, and adjustment of class time will be reviewed. This paper highlights that addressing sleep issues, which are not often considered as a risk factor for depression and academic failure, should be encouraged. Promotion of university and college policies and class schedules that encourage healthy and adequate sleep could have a significant impact on the sleep, learning, and health of college students. Future research to investigate effective and feasible interventions, which disseminate both sleep knowledge and encouragement of healthy sleep habits to college students in a time and cost effective manner, is a priority. PMID:25018659

The prevalence of probable delayed-sleep-phase syndrome in students from junior high school to university in Tottori, Japan.

PubMed

Hazama, Gen-i; Inoue, Yuichi; Kojima, Kazushige; Ueta, Toshiyuki; Nakagome, Kazuyuki

2008-09-01

Delayed sleep phase syndrome (DSPS) is a circadian rhythm sleep disorder with a typical onset in the second decade of life. DSPS is characterized by the sleep-onset insomnia and the difficulty in waking at the desired time in the morning. Although DSPS is associated with inability to attend school, the prevalence has been controversial. To elucidate a change in the prevalence of DSPS among young population, epidemiological survey was conducted on Japanese students. A total of 4,971 students of junior high school, senior high school, and university were enrolled in this cross sectional study in Tottori Prefecture. They answered anonymous screening questionnaire regarding school schedule, sleep hygiene and symptomatic items of sleep disorders. The prevalence of probable DSPS was estimated at 0.48% among the total subject students without gender difference. In university, the prevalence of the last year students showed the highest value (1.66%), while that of the first year students showed the lowest value (0.09%) among all school years from junior high school to university. The prevalence increased with advancing university school years. Thus, a considerable number of Japanese students are affected with DSPS. Senior students of university are more vulnerable to the disorder than younger students. Appropriate school schedule may decrease the mismatch between the individual's sleep-wake cycle and the school schedule. Promotion of a regular sleep habit is necessary to prevent DSPS among this population.

Validating and Verifying Biomathematical Models of Human Fatigue

NASA Technical Reports Server (NTRS)

Martinez, Siera Brooke; Quintero, Luis Ortiz; Flynn-Evans, Erin

2015-01-01

Airline pilots experience acute and chronic sleep deprivation, sleep inertia, and circadian desynchrony due to the need to schedule flight operations around the clock. This sleep loss and circadian desynchrony gives rise to cognitive impairments, reduced vigilance and inconsistent performance. Several biomathematical models, based principally on patterns observed in circadian rhythms and homeostatic drive, have been developed to predict a pilots levels of fatigue or alertness. These models allow for the Federal Aviation Administration (FAA) and commercial airlines to make decisions about pilot capabilities and flight schedules. Although these models have been validated in a laboratory setting, they have not been thoroughly tested in operational environments where uncontrolled factors, such as environmental sleep disrupters, caffeine use and napping, may impact actual pilot alertness and performance. We will compare the predictions of three prominent biomathematical fatigue models (McCauley Model, Harvard Model, and the privately-sold SAFTE-FAST Model) to actual measures of alertness and performance. We collected sleep logs, movement and light recordings, psychomotor vigilance task (PVT), and urinary melatonin (a marker of circadian phase) from 44 pilots in a short-haul commercial airline over one month. We will statistically compare with the model predictions to lapses on the PVT and circadian phase. We will calculate the sensitivity and specificity of each model prediction under different scheduling conditions. Our findings will aid operational decision-makers in determining the reliability of each model under real-world scheduling situations.

School Schedules Affect Sleep Timing in Children and Contribute to Partial Sleep Deprivation

ERIC Educational Resources Information Center

Anacleto, Tâmile Stella; Adamowicz, Taísa; Simões da Costa Pinto, Laura; Louzada, Fernando Mazzilli

2014-01-01

Although the environmental light/dark cycle is the main zeitgeber for the human species, the social cues seem to be important in the synchronization of circadian rhythms. In Brazil, the existence of two school schedules--one with only morning classes (MG) and other with only afternoon classes (AG)--allows the investigation of the effect of school…

What keeps low-SES children from sleeping well: the role of presleep worries and sleep environment

PubMed Central

Bagley, Erika J.; Kelly, Ryan J.; Buckhalt, Joseph A.; El-Sheikh, Mona

2014-01-01

Objectives Children in families of low socioeconomic status (SES) have been found to have poor sleep, yet the reasons for this finding are unclear. Two possible mediators, presleep worries and home environment conditions, were investigated as indirect pathways between SES and children’s sleep. Participants/Methods The participants consisted of 271 children (M (age) = 11.33 years; standard deviation (SD) = 7.74 months) from families varying in SES as indexed by the income-to-needs ratio. Sleep was assessed with actigraphy (sleep minutes, night waking duration, and variability in sleep schedule) and child self-reported sleep/wake problems (e.g., oversleeping and trouble falling asleep) and sleepiness (e.g., sleeping in class and falling asleep while doing homework). Presleep worries and home environment conditions were assessed with questionnaires. Results Lower SES was associated with more subjective sleep/wake problems and daytime sleepiness, and increased exposure to disruptive sleep conditions and greater presleep worries were mediators of these associations. In addition, environmental conditions served as an intervening variable linking SES to variability in an actigraphy-derived sleep schedule, and, similarly, presleep worry was an intervening variable linking SES to actigraphy-based night waking duration. Across sleep parameters, the model explained 5–29% of variance. Conclusions Sleep environment and psychological factors are associated with socioeconomic disparities, which affect children’s sleep. PMID:25701537

What keeps low-SES children from sleeping well: the role of presleep worries and sleep environment.

PubMed

Bagley, Erika J; Kelly, Ryan J; Buckhalt, Joseph A; El-Sheikh, Mona

2015-04-01

Children in families of low socioeconomic status (SES) have been found to have poor sleep, yet the reasons for this finding are unclear. Two possible mediators, presleep worries and home environment conditions, were investigated as indirect pathways between SES and children's sleep. The participants consisted of 271 children (M (age) = 11.33 years; standard deviation (SD) = 7.74 months) from families varying in SES as indexed by the income-to-needs ratio. Sleep was assessed with actigraphy (sleep minutes, night waking duration, and variability in sleep schedule) and child self-reported sleep/wake problems (e.g., oversleeping and trouble falling asleep) and sleepiness (e.g., sleeping in class and falling asleep while doing homework). Presleep worries and home environment conditions were assessed with questionnaires. Lower SES was associated with more subjective sleep/wake problems and daytime sleepiness, and increased exposure to disruptive sleep conditions and greater presleep worries were mediators of these associations. In addition, environmental conditions served as an intervening variable linking SES to variability in an actigraphy-derived sleep schedule, and, similarly, presleep worry was an intervening variable linking SES to actigraphy-based night waking duration. Across sleep parameters, the model explained 5-29% of variance. Sleep environment and psychological factors are associated with socioeconomic disparities, which affect children's sleep. Copyright © 2014 Elsevier B.V. All rights reserved.

Energy latency tradeoffs for medium access and sleep scheduling in wireless sensor networks

NASA Astrophysics Data System (ADS)

Gang, Lu

Wireless sensor networks are expected to be used in a wide range of applications from environment monitoring to event detection. The key challenge is to provide energy efficient communication; however, latency remains an important concern for many applications that require fast response. The central thesis of this work is that energy efficient medium access and sleep scheduling mechanisms can be designed without necessarily sacrificing application-specific latency performance. We validate this thesis through results from four case studies that cover various aspects of medium access and sleep scheduling design in wireless sensor networks. Our first effort, DMAC, is to design an adaptive low latency and energy efficient MAC for data gathering to reduce the sleep latency. We propose staggered schedule, duty cycle adaptation, data prediction and the use of more-to-send packets to enable seamless packet forwarding under varying traffic load and channel contentions. Simulation and experimental results show significant energy savings and latency reduction while ensuring high data reliability. The second research effort, DESS, investigates the problem of designing sleep schedules in arbitrary network communication topologies to minimize the worst case end-to-end latency (referred to as delay diameter). We develop a novel graph-theoretical formulation, derive and analyze optimal solutions for the tree and ring topologies and heuristics for arbitrary topologies. The third study addresses the problem of minimum latency joint scheduling and routing (MLSR). By constructing a novel delay graph, the optimal joint scheduling and routing can be solved by M node-disjoint paths algorithm under multiple channel model. We further extended the algorithm to handle dynamic traffic changes and topology changes. A heuristic solution is proposed for MLSR under single channel interference. In the fourth study, EEJSPC, we first formulate a fundamental optimization problem that provides tunable energy-latency-throughput tradeoffs with joint scheduling and power control and present both exponential and polynomial complexity solutions. Then we investigate the problem of minimizing total transmission energy while satisfying transmission requests within a latency bound, and present an iterative approach which converges rapidly to the optimal parameter settings.

Scheduled Evening Sleep and Enhanced Lighting Improve Adaptation to Night Shift Work in Older Adults

PubMed Central

Chinoy, Evan D.; Harris, Michael P.; Kim, Min Ju; Wang, Wei; Duffy, Jeanne F.

2017-01-01

Objectives We tested whether a sleep and circadian-based treatment shown to improve circadian adaptation to night shifts and attenuate negative effects on alertness, performance, and sleep in young adults would also be effective in older adults. Methods We assessed subjective alertness, sustained attention (psychomotor vigilance task, PVT), sleep duration (actigraphy), and circadian timing (salivary dim-light melatonin onset, DLMO) in eighteen older adults (57.2±3.8 y; mean±SD) in a simulated shift work protocol. Four day shifts were followed by three night shifts in the laboratory. Participants slept at home and were randomized to either the Treatment Group (scheduled evening sleep and enhanced lighting during the latter half of night shifts), or Control Group (ad lib sleep and typical lighting during night shifts). Results Compared to day shifts, alertness and sustained attention declined on the first night shift in both groups, and was worse in the latter half of the night shifts. Alertness and attention improved on nights 2 and 3 for the Treatment Group but remained lower for the Control Group. Sleep duration in the Treatment Group remained similar to baseline (6–7 h) following night shifts, but was shorter (3–5 h) following night shifts in the Control Group. Treatment Group circadian timing advanced by 169.3±16.1 min (mean±SEM) but did not shift (−9.7±9.9 min) in the Control Group. Conclusions The combined treatment of scheduled evening sleep and enhanced lighting increased sleep duration and partially aligned circadian phase with sleep and work timing, resulting in improved night shift alertness and performance. PMID:27566781

The effect of intermittent fasting during Ramadan on sleep, sleepiness, cognitive function, and circadian rhythm.

PubMed

Qasrawi, Shaden O; Pandi-Perumal, Seithikurippu R; BaHammam, Ahmed S

2017-09-01

Studies have shown that experimental fasting can affect cognitive function, sleep, and wakefulness patterns. However, the effects of experimental fasting cannot be generalized to fasting during Ramadan due to its unique characteristics. Therefore, there has been increased interest in studying the effects of fasting during Ramadan on sleep patterns, daytime sleepiness, cognitive function, sleep architecture, and circadian rhythm. In this review, we critically discuss the current research findings in those areas during the month of Ramadan. Available data that controlled for sleep/wake schedule, sleep duration, light exposure, and energy expenditure do not support the notion that Ramadan intermittent fasting increases daytime sleepiness and alters cognitive function. Additionally, recent well-designed studies showed no effect of fasting on circadian rhythms. However, in non-constrained environments that do not control for lifestyle changes, studies have demonstrated sudden and significant delays in bedtime and wake time. Studies that controlled for environmental factors and sleep/wake schedule reported no significant disturbances in sleep architecture. Nevertheless, several studies have consistently reported that the main change in sleep architecture during fasting is a reduction in the proportion of REM sleep.

Fatigue Management in Spaceflight Operations

NASA Technical Reports Server (NTRS)

Whitmire, Alexandra

2011-01-01

Sleep loss and fatigue remain an issue for crewmembers working on the International Space Station, and the ground crews who support them. Schedule shifts on the ISS are required for conducting mission operations. These shifts lead to tasks being performed during the biological night, and sleep scheduled during the biological day, for flight crews and the ground teams who support them. Other stressors have been recognized as hindering sleep in space; these include workload, thinking about upcoming tasks, environmental factors, and inadequate day/night cues. It is unknown if and how other factors such as microgravity, carbon dioxide levels, or increased radiation, may also play a part. Efforts are underway to standardize and provide care for crewmembers, ground controllers and other support personnel. Through collaborations between research and operations, evidenced-based clinical practice guidelines are being developed to equip flight surgeons with the tools and processes needed for treating circadian desynchrony (and subsequent sleep loss) caused by jet lag and shift work. The proper implementation of countermeasures such as schedules, lighting protocols, and cognitive behavioral education can hasten phase shifting, enhance sleep and optimize performance. This panel will focus on Fatigue Management in Spaceflight Operations. Speakers will present on research-based recommendations and technologies aimed at mitigating sleep loss, circadian desynchronization and fatigue on-orbit. Gaps in current mitigations and future recommendations will also be discussed.

Dynamic Hierarchical Sleep Scheduling for Wireless Ad-Hoc Sensor Networks

PubMed Central

Wen, Chih-Yu; Chen, Ying-Chih

2009-01-01

This paper presents two scheduling management schemes for wireless sensor networks, which manage the sensors by utilizing the hierarchical network structure and allocate network resources efficiently. A local criterion is used to simultaneously establish the sensing coverage and connectivity such that dynamic cluster-based sleep scheduling can be achieved. The proposed schemes are simulated and analyzed to abstract the network behaviors in a number of settings. The experimental results show that the proposed algorithms provide efficient network power control and can achieve high scalability in wireless sensor networks. PMID:22412343

Dynamic hierarchical sleep scheduling for wireless ad-hoc sensor networks.

PubMed

Wen, Chih-Yu; Chen, Ying-Chih

2009-01-01

This paper presents two scheduling management schemes for wireless sensor networks, which manage the sensors by utilizing the hierarchical network structure and allocate network resources efficiently. A local criterion is used to simultaneously establish the sensing coverage and connectivity such that dynamic cluster-based sleep scheduling can be achieved. The proposed schemes are simulated and analyzed to abstract the network behaviors in a number of settings. The experimental results show that the proposed algorithms provide efficient network power control and can achieve high scalability in wireless sensor networks.

Impacts of shift work on sleep and circadian rhythms.

PubMed

Boivin, D B; Boudreau, P

2014-10-01

Shift work comprises work schedules that extend beyond the typical "nine-to-five" workday, wherein schedules often comprise early work start, compressed work weeks with 12-hour shifts, and night work. According to recent American and European surveys, between 15 and 30% of adult workers are engaged in some type of shift work, with 19% of the European population reportedly working at least 2 hours between 22:00 and 05:00. The 2005 International Classification of Sleep Disorders estimates that a shift work sleep disorder can be found in 2-5% of workers. This disorder is characterized by excessive sleepiness and/or sleep disruption for at least one month in relation with the atypical work schedule. Individual tolerance to shift work remains a complex problem that is affected by the number of consecutive work hours and shifts, the rest periods, and the predictability of work schedules. Sleepiness usually occurs during night shifts and is maximal at the end of the night. Impaired vigilance and performance occur around times of increased sleepiness and can seriously compromise workers' health and safety. Indeed, workers suffering from a shift work sleep-wake disorder can fall asleep involuntarily at work or while driving back home after a night shift. Working on atypical shifts has important socioeconomic impacts as it leads to an increased risk of accidents, workers' impairment and danger to public safety, especially at night. The aim of the present review is to review the circadian and sleep-wake disturbances associated with shift work as well as their medical impacts. Copyright © 2014. Published by Elsevier SAS.

Sleep Problems among Taiwanese Children with Autism, Their Siblings and Typically Developing Children

ERIC Educational Resources Information Center

Chou, Miao-Chun; Chou, Wen-Jiun; Chiang, Huey-Ling; Wu, Yu-Yu; Lee, Ju-Chin; Wong, Ching-Ching; Gau, Susan Shur-Fen

2012-01-01

The current study compared the sleep schedules, sleep problems among children with autism, their siblings and typically developing children, and to explore other associated factors with sleep problems. We conducted a case-control study consisting 110 children with autistic disorder, 125 unaffected siblings, and 110 age-, sex-, and parental…

Kids and Sleep: How a Lack of ZZZ's Can Affect Those A's and B's.

ERIC Educational Resources Information Center

Engelhardt, Christin L.; Walsh, James K.

1993-01-01

Sleepy students may not reach their full potential. Most sleepiness results from sleep disorders, circadian factors, or schedules with too little sleep. Consequences of sleepiness include decreased performance, worsened mood, and potential for danger. Parents and professionals must understand the need for sleep and help students obtain enough…

MIP Models and Hybrid Algorithms for Simultaneous Job Splitting and Scheduling on Unrelated Parallel Machines

PubMed Central

Ozmutlu, H. Cenk

2014-01-01

We developed mixed integer programming (MIP) models and hybrid genetic-local search algorithms for the scheduling problem of unrelated parallel machines with job sequence and machine-dependent setup times and with job splitting property. The first contribution of this paper is to introduce novel algorithms which make splitting and scheduling simultaneously with variable number of subjobs. We proposed simple chromosome structure which is constituted by random key numbers in hybrid genetic-local search algorithm (GAspLA). Random key numbers are used frequently in genetic algorithms, but it creates additional difficulty when hybrid factors in local search are implemented. We developed algorithms that satisfy the adaptation of results of local search into the genetic algorithms with minimum relocation operation of genes' random key numbers. This is the second contribution of the paper. The third contribution of this paper is three developed new MIP models which are making splitting and scheduling simultaneously. The fourth contribution of this paper is implementation of the GAspLAMIP. This implementation let us verify the optimality of GAspLA for the studied combinations. The proposed methods are tested on a set of problems taken from the literature and the results validate the effectiveness of the proposed algorithms. PMID:24977204

THE SLEEP OF LONG-HAUL TRUCK DRIVERS

PubMed Central

Mitler, Merrill M.; Miller, James C.; Lipsitz, Jeffrey J.; Walsh, James K.; Wylie, C. Dennis

2008-01-01

Background Fatigue and sleep deprivation are important safety issues for long-haul truck drivers. Methods We conducted round-the-clock electrophysiologic and performance monitoring of four groups of 20 male truck drivers who were carrying revenue-producing loads. We compared four driving schedules, two in the United States (five 10-hour trips of day driving beginning about the same time each day or of night driving beginning about 2 hours earlier each day) and two in Canada (four 13-hour trips of late-night-to-morning driving beginning at about the same time each evening or of afternoon-to-night driving beginning 1 hour later each day). Results Drivers averaged 5.18 hours in bed per day and 4.78 hours of electrophysiologically verified sleep per day over the five-day study (range, 3.83 hours of sleep for those on the steady 13-hour night schedule to 5.38 hours of sleep for those on the steady 10-hour day schedule). These values compared with a mean (±SD) self-reported ideal amount of sleep of 7.1±1 hours a day. For 35 drivers (44 percent), naps augmented the sleep obtained by an average of 0.45±0.31 hour. No crashes or other vehicle mishaps occurred. Two drivers had undiagnosed sleep apnea, as detected by polysomnography. Two other drivers had one episode each of stage 1 sleep while driving, as detected by electroencephalography. Forty-five drivers (56 percent) had at least 1 six-minute interval of drowsiness while driving, as judged by analysis of video recordings of their faces; 1067 of the 1989 six-minute segments (54 percent) showing drowsy drivers involved just eight drivers. Conclusions Long-haul truck drivers in this study obtained less sleep than is required for alertness on the job. The greatest vulnerability to sleep or sleep-like states is in the late night and early morning. PMID:9287232

A sipometer for measuring motivation to consume and reward value of foods and beverages in humans: Description and proof of principle.

PubMed

Hogenkamp, P S; Shechter, A; St-Onge, M-P; Sclafani, A; Kissileff, H R

2017-03-15

New methods, derived from animal work, for measuring food reward value (i.e. reinforcing value of food), and motivation (i.e. strength of desire) to consume, in humans are described and validated. A sipping device (sipometer) was developed that permits access to a liquid food or beverage on two reward schedules: continuous reinforcement (CR) and progressively increasing time spent exerting pressure on a straw (PR-schedule). In addition, a pictorial scale showing a cup, from which the 'amount wanted' could be marked was used to pre-test potential consumption. Intake, time spent sipping, breakpoint, and pressure exerted were the main dependent variables measured. Three pilot experiments were conducted. In Experiment 1, participants (n=8) consumed yogurt shakes after a 1-h or 21-h food deprivation period on both schedules. In Experiment 2, participants (n=8) sham-consumed (i.e. spit out) sweet and non-sweet beverages, utilizing both schedules. In Experiment 3, sham-consuming sweet and non-sweet beverages on both schedules and working for shake on the PR schedule were repeated, after three nights of either habitual sleep or short sleep duration (n=7) in a crossover design. In Experiment 1, participants sipped longer after 21-h vs. 1-h of food deprivation (13±3.0 vs. 8.0±2.1s; p=0.04), on the PR schedule. In Experiment 2, sham-intake (p=0.01) and sipping time (p=0.04) were greater for sweet than non-sweet beverages on the PR schedule and a similar, though not conventionally significant, effect was observed for exerted pressure (p=0.09). In both Experiment 2 and Experiment 3 after habitual sleep, on the PR schedule, cumulative pressure difference between sweet and non-sweet beverage increased with difference in amount wanted in the taste test. In contrast, after short sleep participants were less willing to work for sweet taste as their wanting increased, suggesting that sleep deprivation raises desire, but lowers behavioral output. Taken together these results demonstrate that the sipometer and associated ratings are reliable and useful measures of motivation to consume and reward value in humans. Participants were more motivated to obtain access to sweet beverages, especially when these were better liked than to obtain access to non-sweet beverages. Copyright © 2017 Elsevier Inc. All rights reserved.

A sipometer for measuring motivation to consume and reward value of foods and beverages in humans: Description and proof of principle

PubMed Central

Hogenkamp, PS; Shechter, A.; St-Onge, M-P; Sclafani, A; Kissileff, HR

2017-01-01

New methods, derived from animal work, for measuring food reward value (i.e. reinforcing value of food), and motivation (i.e. strength of desire) to consume, in humans are described and validated. A sipping device (sipometer) was developed that permits access to a liquid food or beverage on two reward schedules: continuous reinforcement (CR) and progressively increasing time spent exerting pressure on a straw (PR-schedule). In addition, a pictorial scale showing a cup, from which the ‘amount wanted’ could be marked was used to pre-test potential consumption. Intake, time spent sipping, breakpoint, and pressure exerted were the main dependent variables measured. Three pilot experiments were conducted. In Experiment 1, participants (n = 8) consumed yogurt shakes after a 1-h or 21-h food deprivation period on both schedules. In Experiment 2, participants (n = 8) sham-consumed (i.e. spit out) sweet and non-sweet beverages, utilizing both schedules. In Experiment 3, sham-consuming sweet and non-sweet beverages on both schedules and working for shake on the PR schedule were repeated, after three nights of either habitual sleep or short sleep duration (n = 7) in a crossover design. In Experiment 1, participants sipped longer after 21-h vs. 1-h of food deprivation (13 ± 3.0 vs. 8.0 ± 2.1 s; p = 0.04), on the PR schedule. In Experiment 2, sham-intake (p = 0.01) and sipping time (p = 0.04) were greater for sweet than non-sweet beverages on the PR schedule and a similar, though not conventionally significant, effect was observed for exerted pressure (p = 0.09). In both Experiment 2 and Experiment 3 after habitual sleep, on the PR schedule, cumulative pressure difference between sweet and non-sweet beverage increased with difference in amount wanted in the taste test. In contrast, after short sleep participants were less willing to work for sweet taste as their wanting increased, suggesting that sleep deprivation raises desire, but lowers behavioral output. Taken together these results demonstrate that the sipometer and associated ratings are reliable and useful measures of motivation to consume and reward value in humans. Participants were more motivated to obtain access to sweet beverages, especially when these were better liked than to obtain access to non-sweet beverages. PMID:28089706

Sleep and Academic Performance in U.S. Military Training and Education Programs

ERIC Educational Resources Information Center

Miller, Nita Lewis; Shattuck, Lawrence G.; Matsangas, Panagiotis; Dyche, Jeff

2008-01-01

This review examines the effects of military training regimes, which might include some degree of sleep deprivation, on sleep-wake schedules. We report a 4-year longitudinal study of sleep patterns of cadets at the United States Military Academy and the consequences of an extension of sleep from 6 to 8 hr per night at the United States Navy's…

Dynamic circadian modulation in a biomathematical model for the effects of sleep and sleep loss on waking neurobehavioral performance.

PubMed

McCauley, Peter; Kalachev, Leonid V; Mollicone, Daniel J; Banks, Siobhan; Dinges, David F; Van Dongen, Hans P A

2013-12-01

Recent experimental observations and theoretical advances have indicated that the homeostatic equilibrium for sleep/wake regulation--and thereby sensitivity to neurobehavioral impairment from sleep loss--is modulated by prior sleep/wake history. This phenomenon was predicted by a biomathematical model developed to explain changes in neurobehavioral performance across days in laboratory studies of total sleep deprivation and sustained sleep restriction. The present paper focuses on the dynamics of neurobehavioral performance within days in this biomathematical model of fatigue. Without increasing the number of model parameters, the model was updated by incorporating time-dependence in the amplitude of the circadian modulation of performance. The updated model was calibrated using a large dataset from three laboratory experiments on psychomotor vigilance test (PVT) performance, under conditions of sleep loss and circadian misalignment; and validated using another large dataset from three different laboratory experiments. The time-dependence of circadian amplitude resulted in improved goodness-of-fit in night shift schedules, nap sleep scenarios, and recovery from prior sleep loss. The updated model predicts that the homeostatic equilibrium for sleep/wake regulation--and thus sensitivity to sleep loss--depends not only on the duration but also on the circadian timing of prior sleep. This novel theoretical insight has important implications for predicting operator alertness during work schedules involving circadian misalignment such as night shift work.

A systematic review of the sleep, sleepiness, and performance implications of limited wake shift work schedules.

PubMed

Short, Michelle A; Agostini, Alexandra; Lushington, Kurt; Dorrian, Jillian

2015-09-01

The aim of this review was to identify which limited wake shift work schedules (LWSW) best promote sleep, alertness, and performance. LWSW are fixed work/rest cycles where the time-at-work does is ≤8 hours and there is >1 rest period per day, on average, for ≥2 consecutive days. These schedules are commonly used in safety-critical industries such as transport and maritime industries. Literature was sourced using PubMed, Embase, PsycInfo, Scopus, and Google Scholar databases. We identified 20 independent studies (plus a further 2 overlapping studies), including 5 laboratory and 17 field-based studies focused on maritime watch keepers, ship bridge officers, and long-haul train drivers. The measurement of outcome measures was varied, incorporating subjective and objective measures of sleep: sleep diaries (N=5), actigraphy (N=4), and polysomnography, (N=3); sleepiness: Karolinska Sleepiness Scale (N=5), visual analog scale (VAS) alertness (N=2) and author-derived measures (N=2); and performance: Psychomotor Vigilance Test (PVT) (N=5), Reaction Time or Vigilance tasks (N=4), Vector and Letter Cancellation Test (N=1), and subjective performance (N=2). Of the three primary rosters examined (6 hours-on/6 hours-off, 8 hours-on/8 hours-off and 4 hours-on/8 hours-off), the 4 hours-on/8 hours-off roster was associated with better sleep and lower levels of sleepiness. Individuals working 4 hours-on/8 hours-off rosters averaged 1 hour more sleep per night than those working 6 hours-on/6 hours-off and 1.3 hours more sleep than those working 8 hours-on/8 hours-off (P<0.01). More broadly, findings indicate that LWSW schedules were associated with better sleep and lower sleepines in the case of (i) shorter time-at-work, (ii) more frequent rest breaks, (iii) shifts that start and end at the same clock time every 24 hours, and (iv) work shifts commencing in the daytime (as opposed to night). The findings for performance remain incomplete due to the small number of studies containing a performance measure and the heterogeneity of performance measures within those that did. The literature supports the utility of LWSW in industries where individuals sleep at or near the workplace as they facilitate at least some sleep during the biological night and minimize deficits associated with time-on-shift with shorter shifts. Overall, the 4 hour-on/8 hour-off roster best promoted sleep and minimized sleepiness compared to other LWSW schedules. Nevertheless, and considering the safety-critical nature of industries which employ LWSW, the limited literature needs to be greatly expanded with specific focus on the consequences for performance and comparison to mainstream rosters.

Relationship between shift work schedule and self-reported sleep quality in Chinese employees.

PubMed

Ma, Yifei; Wei, Fu; Nie, Guanghui; Zhang, Li'e; Qin, Jian; Peng, Suwan; Xiong, Feng; Zhang, Zhiyong; Yang, Xiaobo; Peng, Xiaowu; Wang, Mingjun; Zou, Yunfeng

2018-02-01

Few studies have reported on the effects of fixed and rotating shift systems on the prevalence of sleep disturbance. Thus, in this study, the relationships between different work schedules and sleep disturbance in Chinese workers were investigated. A total of 2180 workers aged 19-65 years responded to the self-report questionnaire on shift work schedule (fixed day-shift, fixed night-shift, two-shift or three-shift system), working hours a day, and working days a week, physical effort, subjective sleep quality and subjective mental state. It was found that the rotating shift workers, namely, two- and three-shift workers, exhibited higher risks of sleep disturbance than with the fixed day-shift workers did (OR 1.37; 95% CI 1.07to 1.74; and OR 2.19; 95% CI 1.52 to 3.15, respectively). The risk was particularly high among two- or three-shift workers who worked more than 8 hours a day or more than 5 days a week and among three-shift workers who reported both light and heavy physical effort at work. Moreover, the two- and three-shift workers (rotating shift workers) suffered from poorer sleep quality than the fixed night shift workers did (OR 1.84; 95% CI 1.01 to 3.32; and OR 2.94; 95% CI 1.53 to 5.64, respectively). Consequently, rotating shift work (two- and three-shift work) is a risk factor for sleep disturbance, and the fixed work rhythm may contribute to the quality of sleep.

Sleep inertia, sleep homeostatic, and circadian influences on higher-order cognitive functions

PubMed Central

Ronda, Joseph M.; Czeisler, Charles A.; Wright, Kenneth P.

2016-01-01

Summary Sleep inertia, sleep homeostatic, and circadian processes modulate cognition, including reaction time, memory, mood, and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-daylong study that included two 14-daylong 28h forced desynchrony protocols, to examine separate and interacting influences of sleep inertia, sleep homeostasis, and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved over the first ~2-4h of wakefulness (sleep inertia); worsened thereafter until scheduled bedtime (sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~9AM and ~9PM respectively, in individuals with a habitual waketime of 7AM). The relative influences of sleep inertia, sleep homeostasis, and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation, and/or upon awakening from sleep. PMID:25773686

Association of TV watching with sleep problems in a church-going population.

PubMed

Serrano, Salim; Lee, Jerry W; Dehom, Salem; Tonstad, Serena

2014-01-01

Sensory stimuli/inactivity may affect sleep. Sleep problems are associated with multiple health problems. We assessed TV habits in the Adventist Health Study-2 at baseline and sleep problems in the Biopsychosocial Religion and Health Study 1 to 4 years later. After exclusions, 3914 subjects split equally into TV watchers less than 2 hours per day or 2 or more hours per day. Watching TV 2 or more hours per day predicted problems falling asleep, middle of the night awakening, and waking early with inability to sleep again in multiple logistic regression. Excess TV watching disturbed sleep induction and quality, though the relationship may be bidirectional. TV habits should be considered in individuals with sleep problems.

Sleep problems and computer use during work and leisure: Cross-sectional study among 7800 adults.

PubMed

Andersen, Lars Louis; Garde, Anne Helene

2015-01-01

Previous studies linked heavy computer use to disturbed sleep. This study investigates the association between computer use during work and leisure and sleep problems in working adults. From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners on daytime schedule (N = 7883) replied to the Bergen insomnia scale and questions on weekly duration of computer use. Results showed that sleep problems for three or more days per week (average of six questions) were experienced by 14.9% of the respondents. Logistic regression analyses, controlled for gender, age, physical and psychosocial work factors, lifestyle, chronic disease and mental health showed that computer use during leisure for 30 or more hours per week (reference 0-10 hours per week) was associated with increased odds of sleep problems (OR 1.83 [95% CI 1.06-3.17]). Computer use during work and shorter duration of computer use during leisure were not associated with sleep problems. In conclusion, excessive computer use during leisure - but not work - is associated with sleep problems in adults working on daytime schedule.

Does age affect the relationship between control at work and sleep disturbance for shift workers?

PubMed

Loudoun, Rebecca Jane; Muurlink, Olav; Peetz, David; Murray, Georgina

2014-12-01

Among miners, shift work, aging and lack of control at work may be factors leading to increased sleep problems. Such risk factors may also operate in interaction, resulting in an even increased harm for sleep disruption. The present study aims at evaluating these relationships drawing on a sample of Australian mine and energy workers and their partners. The workers were mainly men. All performed shift work that included either nights (95%) or multiple shifts (92%), usually both (87%), while 36% were aged 50 years or above. The results show that low latitude over work activities is associated with higher sleep disturbances across the sample, though the effects are clearer amongst younger workers. By contrast, for younger workers, control over shift scheduling is not associated with sleep disturbances but for workers aged 50 or more, low control results in more sleep disturbance. Misalignment between shift workers and partner work schedules, and partner dissatisfaction with shift worker's employment and shift worker's work-life balance, are also associated with more sleep disturbances amongst shift workers.

5 CFR 551.432 - Sleep time.

Code of Federal Regulations, 2011 CFR

2011-01-01

... amount of bona fide sleep and meal time that may be excluded from hours of work may not exceed 8 hours in... considered hours of work. (e) On-duty sleep and meal time during regularly scheduled hours for which standby... firefighters compensated under 5 U.S.C. 5545b, on-duty sleep and meal time may not be excluded from hours of...

5 CFR 551.432 - Sleep time.

Code of Federal Regulations, 2010 CFR

2010-01-01

... amount of bona fide sleep and meal time that may be excluded from hours of work may not exceed 8 hours in... considered hours of work. (e) On-duty sleep and meal time during regularly scheduled hours for which standby... firefighters compensated under 5 U.S.C. 5545b, on-duty sleep and meal time may not be excluded from hours of...

The Effects of the Mars Exploration Rovers (MER) Work Schedule Regime on Locomotor Activity Circadian Rhythms, Sleep and Fatigue

NASA Technical Reports Server (NTRS)

DeRoshia, Charles W.; Colletti, Laura C.; Mallis, Melissa M.

2008-01-01

This study assessed human adaptation to a Mars sol by evaluating sleep metrics obtained by actigraphy and subjective responses in 22 participants, and circadian rhythmicity in locomotor activity in 9 participants assigned to Mars Exploration Rover (MER) operational work schedules (24.65 hour days) at the Jet Propulsion Laboratory in 2004. During MER operations, increased work shift durations and reduced sleep durations and time in bed were associated with the appearance of pronounced 12-hr (circasemidian) rhythms with reduced activity levels. Sleep duration, workload, and circadian rhythm stability have important implications for adaptability and maintenance of operational performance not only of MER operations personnel but also in space crews exposed to a Mars sol of 24.65 hours during future Mars missions.

Sleep debt and depression in female college students.

PubMed

Regestein, Quentin; Natarajan, Viji; Pavlova, Milena; Kawasaki, Susan; Gleason, Ray; Koff, Elissa

2010-03-30

The objective of the study was to evaluate relationships between sleep habits and depressive symptoms. Pilot study data were collected about sleep schedules, related factors and depression in female college students to find whether their sleep schedules correlate with affective symptoms. In the subsequent main study, similar information was collected under more controlled conditions. Depression was measured using the CES-D (Center for Epidemiologic Studies Depression Scale) and HAM-D-3 (modified Hamilton Depression Rating Scale). Response rates were 31.3% of eligible students for the pilot survey and 71.6% for the main study. Both studies showed that about 20% of students reported weekday sleep debts of greater than 2 h and about 28% reported significantly greater sleep debt and had significantly higher depression scores (P<0.0001) than other students. Melancholic symptoms indicated by high CES-D scores (>24), were observed in 24% of students. Sleep problems explained 13% of the variance for both the CESD scale and the HAM-D-3 scale. Among female college students, those who report a sleep debt of at least 2 h or significant daytime sleepiness have a higher risk of reporting melancholic symptoms than others. Copyright 2008 Elsevier Ltd. All rights reserved.

Sleep inertia, sleep homeostatic and circadian influences on higher-order cognitive functions.

PubMed

Burke, Tina M; Scheer, Frank A J L; Ronda, Joseph M; Czeisler, Charles A; Wright, Kenneth P

2015-08-01

Sleep inertia, sleep homeostatic and circadian processes modulate cognition, including reaction time, memory, mood and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-day-long study that included two 14-day-long 28-h forced desynchrony protocols to examine separate and interacting influences of sleep inertia, sleep homeostasis and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved during the first ~2-4 h of wakefulness (decreasing sleep inertia); worsened thereafter until scheduled bedtime (increasing sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~09:00 and ~21:00 hours, respectively, in individuals with a habitual wake time of 07:00 hours). The relative influences of sleep inertia, sleep homeostasis and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation and/or upon awakening from sleep. © 2015 European Sleep Research Society.

The effect of nightly nasal CPAP treatment on nocturnal hypoxemia and sleep disorders in mustard gas-injured patients.

PubMed

Vahedi, Ensieh; Fazeli Varzaneh, Ali Reza; Ghanei, Mostafa; Afsharpaiman, Shahla; Poursaleh, Zohre

2014-12-01

Sleep-related breathing disorders are associated with unusual respiratory pattern or an abnormal reduction in gas exchange during sleep that is common in sulfur mustard (SM) exposure. We compared 57 Iranian male patients injured with SM and had any complaints of sleep problems with an age-matched group of 21 Iranian male patients who had complaints of sleep problems and were not chemically injured; this group had Epworth Sleepiness Scale (ESS) above 10 and whom referred for polysomnography. Split-night studies were performed for patients with diagnostic polysomnography for obstructive sleep apnea (OSA) and respiratory events. We then studied respiratory events including episodes of OSA, apnea-hypopnea index (AHI) and respiratory disturbance index (RDI). The mean age in mustard-exposed patients was 48.14±8.04 years and in age-matched group, 48.19±8.39 years. In mustard exposed patients, there were statistical differences for the episodes of OSA (p=0.001), AHI (p=0.001), and RDI (p=0.001) between two segments of split-night studies. In the age-matched group, there were statistically differences for each parameter (episodes of OSA (p=0.001), AHI (p=0.001), and RDI (p=0.001)). There were no significant differences between two groups. This study indicated that the incidence of respiratory events and nocturnal hypoxemia during sleep in mustard-exposed patients were high and treatment with CPAP significantly reduced all these events.

Effect of extended-release dexmethylphenidate and mixed amphetamine salts on sleep: a double-blind, randomized, crossover study in youth with attention-deficit hyperactivity disorder.

PubMed

Santisteban, J A; Stein, M A; Bergmame, L; Gruber, R

2014-09-01

We sought to determine the dose-response effects of extended-release (ER) dexmethylphenidate (d-MPH) and ER mixed amphetamine salts (MAS) on objective measures of sleep. This was an 8-week, double-blind, placebo-controlled, randomized, two period, crossover study of youth with attention-deficit hyperactivity disorder (ADHD) as confirmed by the Kiddie Schedule for Affective Disorders for School-Age Children-Present and Lifetime version (K-SADS-PL). Children aged 10-17 years were recruited from clinical practice, colleague referrals, and flyers. Participants were randomized to initially receive either d-MPH or MAS. During each 4-week drug period, children received three dose levels (10, 20, and 25/30 mg) in ascending order, with placebo substituted for active medication in a randomized fashion during 1 week of the study. After 4 weeks, participants were switched to the alternative medication for another 4 weeks of treatment. The main outcome measure was sleep duration as measured by actigraphy. Children, parents, and researchers were blinded to drug, dose, and placebo status. Sixty-five participants met the inclusion criteria and were enrolled in the study. Of these, 37 participants with sufficient sleep data for analysis were included. Sleep schedule measures showed a significant effect for dose on sleep start time (F(1,36) = 6.284; p < 0.05), with a significantly later sleep start time when children were receiving 20- or 30-mg doses, compared with placebo (p < 0.05). A significant dose effect was found on actual sleep duration (F(1,36) = 8.112; p < 0.05), with significantly shorter actual sleep duration for subjects receiving 30 mg compared with those receiving placebo (p < 0.05). There were no significant differences on sleep duration or sleep schedule between the two stimulant medications. The trial is complete and closed to follow-up. Higher stimulant doses were associated with reduced sleep duration and later sleep start times, regardless of medication class. ClinicalTrials.gov: NCT00393042.

Rethinking AASM guideline for split-night polysomnography in Asian patients with obstructive sleep apnea.

PubMed

Kim, Dong-Kyu; Choi, Jihye; Kim, Kyung Rae; Hwang, Kyung-Gyun; Ryu, Seungho; Cho, Seok Hyun

2015-12-01

Split-night polysomnography (SN-PSG) provides both a diagnosis and titration of continuous positive airway pressure over a single night in patients with suspected obstructive sleep apnea (OSA). However, in Asian patients, the diagnostic validity of American Academy of Sleep Medicine (AASM) guidelines for SN-PSG remains uncertain. Therefore, we examined whether the current criteria for SN-PSG are pertinent for Asian patients. We investigated 134 consecutive patients who were diagnosed with OSA (apnea-hypopnea index (AHI) ≥ 5). We divided the raw data (full-night study) into two parts and compared the first 2 h of sleep with the full night of sleep to evaluate the diagnostic precision and accuracy of the first 2 h of sleep. No difference in AHI was observed between the first 2 h and the full night of sleep. A significant correlation of AHI was observed between the first 2 h and the full night of sleep for severe OSA patients (AHI ≥ 30). A correlation coefficient of AHI was higher by the criterion of AHI ≥ 30 than by the criterion of AHI ≥ 40 (r = 0.831 and r = 0.778, respectively), which is the current AASM criterion for SN-PSG. Moreover, the criterion AHI ≥ 30 showed better diagnostic accuracy than the criterion AHI ≥ 40 (89.3 and 88.7 %, respectively). This study found possible evidence supporting different diagnostic criteria for SN-PSG in Asian population. We suggest further studies in other Asian populations to confirm these findings.

Innately Split Model for Job-shop Scheduling Problem

NASA Astrophysics Data System (ADS)

Ikeda, Kokolo; Kobayashi, Sigenobu

Job-shop Scheduling Problem (JSP) is one of the most difficult benchmark problems. GA approaches often fail searching the global optimum because of the deception UV-structure of JSPs. In this paper, we introduce a novel framework model of GA, Innately Split Model (ISM) which prevents UV-phenomenon, and discuss on its power particularly. Next we analyze the structure of JSPs with the help of the UV-structure hypothesys, and finally we show ISM's excellent performance on JSP.

Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure

NASA Technical Reports Server (NTRS)

Duffy, J. F.; Kronauer, R. E.; Czeisler, C. A.

1996-01-01

1. Both the timing of behavioural events (activity, sleep and social interactions) and the environmental light-dark cycle have been reported to contribute to entrainment of human circadian rhythms to the 24 h day. Yet, the relative contribution of those putative behavioural synchronizers to that of light exposure remains unclear. 2. To investigate this, we inverted the schedule of rest, sedentary activity and social contact of thirty-two young men either with or without exposure to bright light. 3. On this inverted schedule, the endogenous component of the core temperature rhythm of subjects who were exposed to bright light showed a significant phase shift, demonstrating that they were adapting to the new schedule. In contrast, the core temperature rhythm of subjects who were not exposed to bright light moved on average 0.2 h later per day and after 10 days had not significantly adapted to the new schedule. 4. The direction of phase shift in the groups exposed to bright light was dependent on the time of bright light exposure, while control subjects drifted to a later hour regardless of the timing of their schedule of sleep timing, social contact and meals. 5. These results support the concept that the light-dark cycle is the most important synchronizer of the human circadian system. They suggest that inversion of the sleep-wake, rest-activity and social contact cycles provides relatively minimal drive for resetting the human circadian pacemaker. 6. These data indicate that interventions designed to phase shift human circadian rhythms for adjustment to time zone changes or altered work schedules should focus on properly timed light exposure.

Teaching Chronobiology and Sleep Habits in School and University

ERIC Educational Resources Information Center

Azevedo, Carolina V. M.; Sousa, Ivanise; Paul, Ketema; MacLeish, Marlene Y.; Mondejar, Ma Teresa; Sarabia, Juan Antonio; Rol, M. Angeles; Madrid, Juan Antonio

2008-01-01

Early morning school schedules are in the opposite direction to the sleep-wake cycle in adolescence and early adulthood. This conflict leads to sleep deprivation and irregular patterns whose consequences are scarcely explored. This article discusses the effects of three educational experiences with high school students, parents, teachers, and…

Resident Performance and Sleep Deprivation: A Review.

ERIC Educational Resources Information Center

Asken, Michael J.; Raham, David C.

1983-01-01

A review of the literature on resident performance and sleep deprivation suggests that current research is sparse and inconclusive, and existing research suggests potentially severe negative effects. It is proposed that justifications for sleep-depriving night call schedules remain untested, and their use as part of residency training should be…

Working multiple jobs over a day or a week: Short-term effects on sleep duration

PubMed Central

Marucci-Wellman, Helen R.; Lombardi, David A.; Willetts, Joanna L.

2016-01-01

ABSTRACT Approximately 10% of the employed population in the United States works in multiple jobs. They are more likely to work long hours and in nonstandard work schedules, factors known to impact sleep duration and quality, and increase the risk of injury. In this study we used multivariate regression models to compare the duration of sleep in a 24-hour period between workers working in multiple jobs (MJHs) with single job holders (SJHs) controlling for other work schedule and demographic factors. We used data from the Bureau of Labor Statistics US American Time Use Survey (ATUS) pooled over a 9-year period (2003–2011). We found that MJHs had significantly reduced sleep duration compared with SJHs due to a number of independent factors, such as working longer hours and more often late at night. Male MJHs, working in their primary job or more than one job on the diary day, also had significantly shorter sleep durations (up to 40 minutes less on a weekend day) than male SJHs, even after controlling for all other factors. Therefore, duration of work hours, time of day working and duration of travel for work may not be the only factors to consider when understanding if male MJHs are able to fit in enough recuperative rest from their busy schedule. Work at night had the greatest impact on sleep duration for females, reducing sleep time by almost an hour compared with females who did not work at night. We also hypothesize that the high frequency or fragmentation of non-leisure activities (e.g. work and travel for work) throughout the day and between jobs may have an additional impact on the duration and quality of sleep for MJHs. PMID:27092404

Working multiple jobs over a day or a week: Short-term effects on sleep duration.

PubMed

Marucci-Wellman, Helen R; Lombardi, David A; Willetts, Joanna L

Approximately 10% of the employed population in the United States works in multiple jobs. They are more likely to work long hours and in nonstandard work schedules, factors known to impact sleep duration and quality, and increase the risk of injury. In this study we used multivariate regression models to compare the duration of sleep in a 24-hour period between workers working in multiple jobs (MJHs) with single job holders (SJHs) controlling for other work schedule and demographic factors. We used data from the Bureau of Labor Statistics US American Time Use Survey (ATUS) pooled over a 9-year period (2003-2011). We found that MJHs had significantly reduced sleep duration compared with SJHs due to a number of independent factors, such as working longer hours and more often late at night. Male MJHs, working in their primary job or more than one job on the diary day, also had significantly shorter sleep durations (up to 40 minutes less on a weekend day) than male SJHs, even after controlling for all other factors. Therefore, duration of work hours, time of day working and duration of travel for work may not be the only factors to consider when understanding if male MJHs are able to fit in enough recuperative rest from their busy schedule. Work at night had the greatest impact on sleep duration for females, reducing sleep time by almost an hour compared with females who did not work at night. We also hypothesize that the high frequency or fragmentation of non-leisure activities (e.g. work and travel for work) throughout the day and between jobs may have an additional impact on the duration and quality of sleep for MJHs.

Scheduled evening sleep and enhanced lighting improve adaptation to night shift work in older adults.

PubMed

Chinoy, Evan D; Harris, Michael P; Kim, Min Ju; Wang, Wei; Duffy, Jeanne F

2016-12-01

We tested whether a sleep and circadian-based treatment shown to improve circadian adaptation to night shifts and attenuate negative effects on alertness, performance and sleep in young adults would also be effective in older adults. We assessed subjective alertness, sustained attention (psychomotor vigilance task, PVT), sleep duration (actigraphy) and circadian timing (salivary dim-light melatonin onset, DLMO) in 18 older adults (57.2±3.8 years; mean±SD) in a simulated shift work protocol. 4 day shifts were followed by 3 night shifts in the laboratory. Participants slept at home and were randomised to either the treatment group (scheduled evening sleep and enhanced lighting during the latter half of night shifts) or control group (ad-lib sleep and typical lighting during night shifts). Compared with day shifts, alertness and sustained attention declined on the first night shift in both groups, and was worse in the latter half of the night shifts. Alertness and attention improved on nights 2 and 3 for the treatment group but remained lower for the control group. Sleep duration in the treatment group remained similar to baseline (6-7 hours) following night shifts, but was shorter (3-5 hours) following night shifts in the control group. Treatment group circadian timing advanced by 169.3±16.1 min (mean±SEM) but did not shift (-9.7±9.9 min) in the control group. The combined treatment of scheduled evening sleep and enhanced lighting increased sleep duration and partially aligned circadian phase with sleep and work timing, resulting in improved night shift alertness and performance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Association between reported sleep need and sleepiness at the wheel: comparative study on French highways between 1996 and 2011

PubMed Central

Quera-Salva, M A; Sauvagnac-Quera, R; Sagaspe, P; Taillard, J; Contrand, B; Micoulaud, J A; Lagarde, E; Barbot, F; Philip, P

2016-01-01

Objective To investigate the evolution over 15 years of sleep schedules, sleepiness at the wheel and driving risk among highway drivers. Methods Comparative survey including questions on usual sleep schedules and before the trip, sleepiness at the wheel, the Epworth sleepiness scale, Basic Nordic Sleep Questionnaire (BNSQ) and a travel questionnaire. Results 80% of drivers stopped by the highway patrol agreed to participate in both studies with a total of 3545 drivers in 2011 and 2196 drivers in 1996 interviewed. After standardisation based on sex, age and mean annual driving distance, drivers in 2011 reported shorter sleep time on week days (p<0.0001), and week-ends (p<0.0001) and shorter optimal sleep time (p<0.0001) compared to 1996 drivers. There were more drivers sleepy at the wheel in 2011 than in 1996 (p<0.0001) and 2.5 times more drivers in 2011 than in 1996 had an Epworth sleepiness score >15 indicating severe sleepiness. Conclusions Even if drivers in 2011 reported good sleep hygiene prior to a highway journey, drivers have reduced their mean weekly sleep duration over 15 years and have a higher risk of sleepiness at the wheel. Sleep hygiene for automobile drivers remains an important concept to address. PMID:28003284

Has Adult Sleep Duration Declined Over the Last 50+ Years?

PubMed Central

Youngstedt, Shawn D.; Goff, Eric E.; Reynolds, Alex M.; Kripke, Daniel F.; Irwin, Michael R.; Bootzin, Richard R.; Khan, Nidha; Jean-Louis, Girardin

2015-01-01

Summary The common assumption that population sleep duration has declined in the past few decades has not been supported by recent reviews, which have been limited to self-reported data. The aim of this review was to assess whether there has been a reduction in objectively recorded sleep duration over the last 50+ years. The literature was searched for studies published from 1960–2013, which assessed objective sleep duration (TST) in healthy normal-sleeping adults. The search found 168 studies that met inclusion criteria, with 257 data points representing 6,052 individuals ages 18–88 years. Data were assessed by comparing the regression lines of age vs. TST in studies conducted between 1960–1989 vs. 1990–2013. Weighted regression analyses assessed the association of year of study with age-adjusted TST across all data points. Regression analyses also assessed the association of year of study with TST separately for 10-year age categories (e.g., ages 18–27 years), and separately for polysomnographic and actigraphic data, and for studies involving a fixed sleep schedule and participants’ customary sleep schedules. Analyses revealed no significant association of sleep duration with study year. The results are consistent with recent reviews of subjective data, which have challenged the notion of a modern epidemic of insufficient sleep. PMID:26478985

Sleeping on Mars: A Hidden Challenge for Human Space Exploration

NASA Technical Reports Server (NTRS)

Flynn-Evans, Erin

2017-01-01

The purpose of this talk is to provide a general public audience with basic information about what it is like to sleep in space. Dr. Flynn-Evans will begin by highlighting how sleep is different in movies and science fiction compared to real life. She will next cover basic information about sleep and circadian rhythms, including how sleep works on earth. She will explain how people have circadian rhythms of different lengths and how the circadian clock has to be re-set each day. She will also describe how jet-lag works as an example of what happens during circadian misalignment. Dr. Flynn-Evans will also describe how sleep is different in space and will highlight the challenges that astronauts face in low-earth orbit. She will discuss how astronauts have a shorter sleep duration in space relative to on the ground and how their schedules can shift due to operational constraints. She will also describe how these issues affect alertness and performance. She will then discuss how sleep and scheduling may be different on a long-duration mission to Mars. She will discuss the differences in light and day length on earth and mars and illustrate how those differences pose significant challenges to sleep and circadian rhythms.

In a randomized case-control trial with 10-years olds suffering from attention deficit/hyperactivity disorder (ADHD) sleep and psychological functioning improved during a 12-week sleep-training program.

PubMed

Keshavarzi, Zahra; Bajoghli, Hafez; Mohamadi, Mohammad Reza; Salmanian, Maryam; Kirov, Roumen; Gerber, Markus; Holsboer-Trachsler, Edith; Brand, Serge

2014-12-01

We tested the hypothesis that sleep training would improve emotional, social and behavioural functioning in children with attention-deficit/hyperactivity disorder (ADHD) compared to children with ADHD without such intervention and to healthy controls. Forty children with ADHD were randomly assigned to intervention and control conditions. Parents of 20 children with ADHD were instructed and thoroughly supervised in improving their children's sleep schedules and sleep behaviour. Parents of the other 20 children with ADHD and parents of 20 healthy children received general information about sleep hygiene. At baseline and 12 weeks later, parents and children completed questionnaires related to children's sleep and psychological functioning. Relative to the control groups, children in the intervention group improved sleep quantitatively and qualitatively (F values < 3.33, P values < 0.05). The intervention group children reported improvements in mood, emotions, and relationships (F values < 2.99, P values < 0.05). Parents reported that their children improved in physical and psychological wellbeing, mood, emotions, relationships, and social acceptance (F values < 3.02, P values < 0.05). Training and monitoring parents of children with ADHD in regulating and supervising children's sleep schedules leads to positive changes in the emotions, behaviour and social lives of these children.

Self-Reported Recovery from 2-Week 12-Hour Shift Work Schedules: A 14-Day Follow-Up.

PubMed

Merkus, Suzanne L; Holte, Kari Anne; Huysmans, Maaike A; van de Ven, Peter M; van Mechelen, Willem; van der Beek, Allard J

2015-09-01

Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work. Sixty-one male offshore employees-20 night workers, 16 swing shift workers, and 25 day workers-rated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1-11) for 14 days after an offshore tour. After the two night-work schedules, differences on the 1(st) day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis. After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05-1.89) and swing shift workers (1.42, 95% confidence interval 1.03-1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found. After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the 1(st) day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality.

Sleep Duration in Rough Sea Conditions.

PubMed

Matsangas, Panagiotis; Shattuck, Nita L; McCauley, Michael E

2015-10-01

Environmental motion can affect shipboard sleep of crewmembers. Slamming and similar harsh motion may interfere with sleep, whereas mild motion and sopite syndrome may enhance sleep. If sleep needs vary by sea condition, this factor should be considered when assessing human performance at sea. The goal of this study was to assess sleep duration in different sea conditions. Crewmembers (N = 52) from a U.S. Navy vessel participated in the study while performing their normal daily schedule of duties. Sleep was assessed with wrist-worn actigraphy. Motion sickness and sopite syndrome were assessed using standardized questionnaires. In rough sea conditions, crewmembers experienced increased severity of motion sickness and sopite syndrome compared to their ratings during calmer sea conditions. Crewmembers slept significantly longer during sea state 5-6 compared to sleep on days with sea state 4 (25% increase) and sea state 3-4 (30% increase). Specifically, daily sleep increased from 6.97 ± 1.24 h in sea state 3-4, to 7.23 ± 1.65 h in sea state 4, to 9.04 ± 2.90 h in sea state 5-6. Although the duration of sleep in rough seas increased significantly compared to calmer sea conditions, causal factors are inconclusive. Accumulated sleep debt, motion-induced fatigue, and sopite syndrome all may have contributed, but results suggest that motion sickness and sopite syndrome were the predominant stressors. If sleep needs increase in severe motion environments, this factor should be taken into account when developing daily activity schedules or when modeling manning requirements on modern ships.

Early childhood sleep and eating problems as predictors of adolescent and adult mood and anxiety disorders.

PubMed

Ong, Say How; Wickramaratne, Priya; Tang, Min; Weissman, Myrna M

2006-11-01

Recent studies have suggested that eating and sleep problems during early childhood may pose as risk factors for mood and anxiety disorders in later life. We aim to study the associations between early childhood sleep and eating problems, specifically high motor activity during sleep and irregularities in sleep/eating schedules, and lifetime history of mood and anxiety disorders. We followed up 164 offspring, who were at high and low risk for major depression by virtue of their parental history (at least one parent had Major Depressive Disorder). Target sleep and eating problems were measured using Dimensions of Temperament Survey (DOTS). The offspring were blindly assessed at 3 times over 20 years using a structured diagnostic interview. Irregularities in sleeping and eating schedules in childhood (low rhythmicity) was associated with adolescent-onset major depression and anxiety disorder, as well as childhood-onset anxiety disorder. High motor activity level during sleep was associated with both childhood-onset and adolescent-onset dysthymic disorder. Neither childhood sleep nor eating irregularities were associated with adult onset psychopathology. Retrospective reports of childhood sleep and eating patterns were derived from parent-reports. Reported problems may overlap with clinical diagnoses. Clinicians should be alerted to parental reports of children's sleep and eating problems suggesting low rhythmicity, as well as high motor activity levels during sleep. These early behaviors may be predictive of subsequent mood and anxiety disorders in childhood and adolescence.

Advanced Numerical Techniques of Performance Evaluation. Volume 1

DTIC Science & Technology

1990-06-01

system scheduling3thread. The scheduling thread then runs any other ready thread that can be found. A thread can only sleep or switch out on itself...Polychronopoulos and D.J. Kuck. Guided Self- Scheduling : A Practical Scheduling Scheme for Parallel Supercomputers. IEEE Transactions on Computers C...Kuck 1987] C.D. Polychronopoulos and D.J. Kuck. Guided Self- Scheduling : A Practical Scheduling Scheme for Parallel Supercomputers. IEEE Trans. on Comp

Temporal Organization of the Sleep-Wake Cycle under Food Entrainment in the Rat

PubMed Central

Castro-Faúndez, Javiera; Díaz, Javier; Ocampo-Garcés, Adrián

2016-01-01

Study Objectives: To analyze the temporal organization of the sleep-wake cycle under food entrainment in the rat. Methods: Eighteen male Sprague-Dawley rats were chronically implanted for polysomnographic recording. During the baseline (BL) protocol, rats were recorded under a 12:12 light-dark (LD) schedule in individual isolation chambers with food and water ad libitum. Food entrainment was performed by means of a 4-h food restriction (FR) protocol starting at photic zeitgeber time 5. Eight animals underwent a 3-h phase advance of the FR protocol (A-FR). We compared the mean curves and acrophases of wakefulness, NREM sleep, and REM sleep under photic and food entrainment and after a phase advance in scheduled food delivery. We further evaluated the dynamics of REM sleep homeostasis and the NREM sleep EEG delta wave profile. Results: A prominent food-anticipatory arousal interval was observed after nine or more days of FR, characterized by increased wakefulness and suppression of REM sleep propensity and dampening of NREM sleep EEG delta activity. REM sleep exhibited a robust nocturnal phase preference under FR that was not explained by a nocturnal REM sleep rebound. The mean curve of sleep-wake states and NREM sleep EEG delta activity remained phase-locked to the timing of meals during the A-FR protocol. Conclusions: Our results support the hypothesis that under food entrainment, the sleep-wake cycle is coupled to a food-entrainable oscillator (FEO). Our findings suggest an unexpected interaction between FEO output and NREM sleep EEG delta activity generators. Citation: Castro-Faúndez J, Díaz J, Ocampo-Garcés A. Temporal organization of the sleep-wake cycle under food entrainment in the rat. SLEEP 2016;39(7):1451–1465. PMID:27091526

Accommodating Adolescent Sleep-Wake Patterns: The Effects of Shifting the Timing of Sleep on Training Effectiveness

PubMed Central

Miller, Nita Lewis; Tvaryanas, Anthony P.; Shattuck, Lawrence G.

2012-01-01

Study Objective: This study evaluated the effect of accommodating adolescent sleep-wake patterns by altering the timing of the major sleep period of US Army recruits. Design: The quasi-experimental study compared recruits assigned to one of two training companies: one with a customary sleep regimen (20:30 to 04:30) while the other employed a phase-delayed sleep regimen (23:00 to 07:00), the latter aligning better with biologically driven sleep-wake patterns of adolescents. Setting: The study was conducted during Basic Combat Training (BCT) at Fort Leonard Wood, Missouri. Trainees: The study included 392 trainees: 209 received the intervention, while 183 composed the Comparison group. Measurements and Results: Demographic and psychophysiological measures were collected on all trainees. Weekly assessments of subjective fatigue and mood, periodic physical fitness, marksmanship scores, and attrition rates from BCT were studied. Actigraphy was collected on approximately 24% of trainees. Based on actigraphy, trainees on the phase-delayed sleep schedule obtained 31 m more sleep/night than trainees on the customary sleep schedule. The Intervention group reported less total mood disturbance relative to baseline. Improvements in marksmanship correlated positively with average nightly sleep during the preceding week when basic marksmanship skills were taught. No differences were seen in physical fitness or attrition rates. In contrast to the Intervention group, the Comparison group was 2.3 times more likely to experience occupationally significant fatigue and 5.5 times more likely to report poor sleep quality. Conclusions: Accommodating adolescent sleep patterns significantly improves mental health and performance in the training environment. Citation: Miller NL; Tvaryanas AP; Shattuck LG. Accommodating adolescent sleep-wake patterns: the effects of shifting the timing of sleep on training effectiveness. SLEEP 2012;35(8):1123-1136. PMID:22851808

Dynamic Circadian Modulation in a Biomathematical Model for the Effects of Sleep and Sleep Loss on Waking Neurobehavioral Performance

PubMed Central

McCauley, Peter; Kalachev, Leonid V.; Mollicone, Daniel J.; Banks, Siobhan; Dinges, David F.; Van Dongen, Hans P. A.

2013-01-01

Recent experimental observations and theoretical advances have indicated that the homeostatic equilibrium for sleep/wake regulation—and thereby sensitivity to neurobehavioral impairment from sleep loss—is modulated by prior sleep/wake history. This phenomenon was predicted by a biomathematical model developed to explain changes in neurobehavioral performance across days in laboratory studies of total sleep deprivation and sustained sleep restriction. The present paper focuses on the dynamics of neurobehavioral performance within days in this biomathematical model of fatigue. Without increasing the number of model parameters, the model was updated by incorporating time-dependence in the amplitude of the circadian modulation of performance. The updated model was calibrated using a large dataset from three laboratory experiments on psychomotor vigilance test (PVT) performance, under conditions of sleep loss and circadian misalignment; and validated using another large dataset from three different laboratory experiments. The time-dependence of circadian amplitude resulted in improved goodness-of-fit in night shift schedules, nap sleep scenarios, and recovery from prior sleep loss. The updated model predicts that the homeostatic equilibrium for sleep/wake regulation—and thus sensitivity to sleep loss—depends not only on the duration but also on the circadian timing of prior sleep. This novel theoretical insight has important implications for predicting operator alertness during work schedules involving circadian misalignment such as night shift work. Citation: McCauley P; Kalachev LV; Mollicone DJ; Banks S; Dinges DF; Van Dongen HPA. Dynamic circadian modulation in a biomathematical model for the effects of sleep and sleep loss on waking neurobehavioral performance. SLEEP 2013;36(12):1987-1997. PMID:24293775

Chronic Moderate Sleep Restriction in Older Long Sleepers and Older Average Duration Sleepers: A Randomized Controlled Trial

PubMed Central

Youngstedt, Shawn D.; Jean-Louis, Girardin; Bootzin, Richard R.; Kripke, Daniel F.; Cooper, Jonnifer; Dean, Lauren R.; Catao, Fabio; James, Shelli; Vining, Caitlyn; Williams, Natasha J.; Irwin, Michael R.

2013-01-01

Epidemiologic studies have consistently shown that sleeping < 7 hr and ≥ 8 hr is associated with increased mortality and morbidity. The risks of short sleep may be consistent with results from experimental sleep deprivation studies. However, there has been little study of chronic moderate sleep restriction and no evaluation of older adults who might be more vulnerable to negative effects of sleep restriction, given their age-related morbidities. Moreover, the risks of long sleep have scarcely been examined experimentally. Moderate sleep restriction might benefit older long sleepers who often spend excessive time in bed (TIB), in contrast to older adults with average sleep patterns. Our aims are: (1) to examine the ability of older long sleepers and older average sleepers to adhere to 60 min TIB restriction; and (2) to contrast effects of chronic TIB restriction in older long vs. average sleepers. Older adults (n=100) (60–80 yr) who sleep 8–9 hr per night and 100 older adults who sleep 6–7.25 hr per night will be examined at 4 sites over 5 years. Following a 2-week baseline, participants will be randomized to one of two 12-week treatments: (1) a sleep restriction involving a fixed sleep-wake schedule, in which TIB is reduced 60 min below each participant’s baseline TIB; (2) a control treatment involving no sleep restriction, but a fixed sleep schedule. Sleep will be assessed with actigraphy and a diary. Measures will include glucose tolerance, sleepiness, depressive symptoms, quality of life, cognitive performance, incidence of illness or accident, and inflammation. PMID:23811325

Summer Travel: Plan Ahead To Stay Healthy

MedlinePlus

... Twery says. “It’s especially important before and during travel to consciously schedule time to sleep.” Too little sleep leads to poor ... and their ability to meet the challenges of travel.” Jet lag is another sleep concern for travelers crossing multiple time zones. Jet lag is often more severe for ...

Meeting Teen Sleep Needs Creatively

ERIC Educational Resources Information Center

Wolfson, Amy R.; Carskadon, Mary A.

2005-01-01

Research on the sleep needs of adolescents and the influence of sleep on learning and behavior have captured the interest of school districts nationwide and in other countries as well. As a result, school officials are being urged to acknowledge the evidence and to adjust school schedules accordingly (e.g., to delay high school start times). The…

The development of lighting countermeasures for sleep disruption and circadian misalignment during spaceflight.

PubMed

Brainard, George C; Barger, Laura K; Soler, Robert R; Hanifin, John P

2016-11-01

The review addresses the development of a new solid-state lighting system for the International Space Station (ISS) that is intended to enhance the illumination of the working and living environment of astronauts and to improve sleep, circadian entrainment, and daytime alertness. Spaceflight missions often expose astronauts and mission support ground crews to atypical sleep-wake cycles and work schedules. A recent, extensive study describes the sleep characteristics and use of sleep-promoting pharmaceuticals in astronauts before, during, and after spaceflight. The acceptability, feasibility, and efficacy of the new ISS solid-state lighting systems are currently being tested in ground-based, analog studies. Installation of this lighting system on the ISS is scheduled to begin later this year. In-flight testing of this lighting system is planned to take place during ISS spaceflight expeditions. If the new ISS lighting system is capable of improving circadian entrainment and sleep during spaceflight, it should enhance astronaut health, performance, well-being, and safety. Such an advance would open the door to future lighting applications for humans living on Earth.

A laboratory comparison of clockwise and counter-clockwise rapidly rotating shift schedules, part I, sleep : final report.

DOT National Transportation Integrated Search

2002-05-01

INTRODUCTION. Many air traffic control specialists work relatively unique counter-clockwise, rapidly rotating shift schedules. Researchers recommend, however, that if rotating schedules are to be used, they should rotate in a clockwise, rather than a...

How do employees prioritise when they schedule their own shifts?

PubMed

Nabe-Nielsen, Kirsten; Lund, Henrik; Ajslev, Jeppe Z; Hansen, Åse Marie; Albertsen, Karen; Hvid, Helge; Garde, Anne Helene

2013-01-01

We investigated how employees prioritised when they scheduled their own shifts and whether priorities depended on age, gender, educational level, cohabitation and health status. We used cross-sectional questionnaire data from the follow-up survey of an intervention study investigating the effect of self-scheduling (n = 317). Intervention group participants were asked about their priorities when scheduling their own shifts succeeded by 17 items covering family/private life, economy, job content, health and sleep. At least half of the participants reported that they were giving high priority to their family life, having consecutive time off, leisure-time activities, rest between shifts, sleep, regularity of their everyday life, health and that the work schedule balanced. Thus, employees consider both their own and the workplace's needs when they have the opportunity to schedule their own shifts. Age, gender, cohabitation and health status were all significantly associated with at least one of these priorities. Intervention studies report limited health effects of self-scheduling. Therefore, we investigated to what extent employees prioritise their health and recuperation when scheduling their own shifts. We found that employees not only consider both their health and family but also the workplace's needs when they schedule their own shifts.

Shift work, age, and performance : investigation of the 2-2-1 shift schedule used in air traffic control facilities. I., The sleep/wake cycle.

DOT National Transportation Integrated Search

1995-05-01

Air Traffic Control Specialists (ATCS) work rotating shift schedules for most of their careers. Specifically, many work a counterclockwise rotating shift schedule, called the 2-2-1, or some variation of the schedule. The 2-2-1 involves rotating from ...

Accommodating adolescent sleep-wake patterns: the effects of shifting the timing of sleep on training effectiveness.

PubMed

Miller, Nita Lewis; Tvaryanas, Anthony P; Shattuck, Lawrence G

2012-08-01

This study evaluated the effect of accommodating adolescent sleep-wake patterns by altering the timing of the major sleep period of US Army recruits. The quasi-experimental study compared recruits assigned to one of two training companies: one with a customary sleep regimen (20:30 to 04:30) while the other employed a phase-delayed sleep regimen (23:00 to 07:00), the latter aligning better with biologically driven sleep-wake patterns of adolescents. The study was conducted during Basic Combat Training (BCT) at Fort Leonard Wood, Missouri. TRAINEES: The study included 392 trainees: 209 received the intervention, while 183 composed the Comparison group. Demographic and psychophysiological measures were collected on all trainees. Weekly assessments of subjective fatigue and mood, periodic physical fitness, marksmanship scores, and attrition rates from BCT were studied. Actigraphy was collected on approximately 24% of trainees. Based on actigraphy, trainees on the phase-delayed sleep schedule obtained 31 m more sleep/night than trainees on the customary sleep schedule. The Intervention group reported less total mood disturbance relative to baseline. Improvements in marksmanship correlated positively with average nightly sleep during the preceding week when basic marksmanship skills were taught. No differences were seen in physical fitness or attrition rates. In contrast to the Intervention group, the Comparison group was 2.3 times more likely to experience occupationally significant fatigue and 5.5 times more likely to report poor sleep quality. Accommodating adolescent sleep patterns significantly improves mental health and performance in the training environment.

Assessing Individual Differences in Adaptation to Extreme Environments: A 36-Hour Sleep Deprivation Study

NASA Technical Reports Server (NTRS)

Martinez, Jacqueline; Cowings, Patricia S.; Toscano, William B.

2012-01-01

In space, astronauts may experience effects of cumulative sleep loss due to demanding work schedules that can result in cognitive performance impairments, mood state deteriorations, and sleep-wake cycle disruption. Individuals who experience sleep deprivation of six hours beyond normal sleep times experience detrimental changes in their mood and performance states. Hence, the potential for life threatening errors increases exponentially with sleep deprivation. We explored the effects of 36-hours of sleep deprivation on cognitive performance, mood states, and physiological responses to identify which metrics may best predict fatigue induced performance decrements of individuals.

Heavy Traffic Feasible Hybrid Intracycle and Cyclic Sleep for Power Saving in 10G-EPON

PubMed Central

Wang, Liqian; Zhang, Zhiguo; Chen, Xue

2014-01-01

Energy consumption in optical access networks costs carriers substantial operational expense (OPEX) every year and is one of contributing factors for the global warming. To reduce energy consumption in the 10-gigabit Ethernet passive optical network (10G-EPON), a hybrid intracycle and cyclic sleep mechanism is proposed in this paper. Under heavy traffic load, optical network units (ONUs) can utilize short idle slots within each scheduling cycle to enter intracycle sleep without postponing data transmission. In this way, energy conservation is achieved even under heavy traffic load with quality of service (QoS) guarantee. Under light traffic load, ONUs perform long cyclic sleep for several scheduling cycles. The adoption of cyclic sleep instead of intracycle sleep under light traffic load can reduce unnecessary frequent transitions between sleep and full active work caused by using intracycle sleep. Further, the Markov chain of the proposed mechanism is established. The performances of the proposed mechanism and existing approaches are analyzed quantitatively based on the chain. For the proposed mechanism, power saving ability with QoS guarantee even under heavy traffic and better power saving performance than existing approaches are verified by the quantitative analysis. Moreover, simulations validate the above conclusions based on the chain. PMID:25177727

Shift work: health, performance and safety problems, traditional countermeasures, and innovative management strategies to reduce circadian misalignment

PubMed Central

Smith, Mark R; Eastman, Charmane I

2012-01-01

There are three mechanisms that may contribute to the health, performance, and safety problems associated with night-shift work: (1) circadian misalignment between the internal circadian clock and activities such as work, sleep, and eating, (2) chronic, partial sleep deprivation, and (3) melatonin suppression by light at night. The typical countermeasures, such as caffeine, naps, and melatonin (for its sleep-promoting effect), along with education about sleep and circadian rhythms, are the components of most fatigue risk-management plans. We contend that these, while better than nothing, are not enough because they do not address the underlying cause of the problems, which is circadian misalignment. We explain how to reset (phase-shift) the circadian clock to partially align with the night-work, day-sleep schedule, and thus reduce circadian misalignment while preserving sleep and functioning on days off. This involves controlling light and dark using outdoor light exposure, sunglasses, sleep in the dark, and a little bright light during night work. We present a diagram of a sleep-and-light schedule to reduce circadian misalignment in permanent night work, or a rotation between evenings and nights, and give practical advice on how to implement this type of plan. PMID:23620685

Prevalence and correlates of poor sleep quality and daytime sleepiness in Belgian truck drivers.

PubMed

Braeckman, Lutgart; Verpraet, Rini; Van Risseghem, Marleen; Pevernagie, Dirk; De Bacquer, Dirk

2011-03-01

Sleepiness and sleep complaints are common among professional drivers. Sleepiness is a considerable problem not only because it affects the drivers' well-being, but also because of the consequences for performance and safety. Assessment of the (self-reported) prevalence and research into the risk factors are thus an important health issue and are also indispensable to prevent productivity loss and work-related accidents and injuries. Therefore, the aim of this study was to describe sleeping, driving, and health characteristics of Belgian truck drivers and to determine occupational and individual factors associated with poor sleep quality and daytime sleepiness. Cross-sectional data were collected using a self-administered questionnaire that included the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Berlin Questionnaire (BQ). The mean (SD) age of the 476 studied truck drivers was 42.7 (10.2) yrs and the mean (SD) body mass index was 27.3 (5.1) kg/m(2). Approximately 47% declared that they drove >50 h/wk and found their work schedule unrealistic. The mean (SD) PSQI score was 4.45 (2.7); poor quality of sleep (PSQI >5) was found in 27.2%. The mean (SD) ESS score was 6.79 (4.17); 18% had a score >10. The BQ indicated that 21.5% had a higher risk on obstructive sleep apnea. In multiple logistic regression analysis, low educational level (odds ratio [OR] 1.86), current smoking (OR 1.75), unrealistic work schedule (OR 1.75), and risk for obstructive sleep apnea (OR 2.97) were found to be independent correlates of daytime sleepiness. Poor sleep quality was significantly associated with poor self-perceived health (OR 1.95), unrealistic work schedule (OR 2.85), low job satisfaction (OR 1.91), and less driving experience (OR 1.73). These results show that poor sleep quality and daytime sleepiness were prevalent in Belgian truck drivers. Taking into account that several significant correlates with respect to these sleep problems were identified both at the individual and the occupational level, comprehensive countermeasures to improve working conditions and organization are needed, as well as health promotion interventions, to ensure the safety and well-being of truck drivers.

Research on sleep, circadian rhythms and aging - Applications to manned spaceflight

NASA Technical Reports Server (NTRS)

Czeisler, Charles A.; Chiasera, August J.; Duffy, Jeanne F.

1991-01-01

Disorders of sleep and circadian rhythmicity are characteristic of both advancing age and manned spaceflight. Sleep fragmentation, reduced nocturnal sleep tendency and sleep efficiency, reduced daytime alertness, and increased daytime napping are common to both of these conditions. Recent research on the pathophysiology and treatment of disrupted sleep in older people has led to a better understanding of how the human circadian pacemaker regulates the timing of the daily sleep-wake cycle and how it responds to the periodic changes in the light-dark cycle to which we are ordinarily exposed. These findings have led to new treatments for some of the sleep disorders common to older individuals, using carefully timed exposure to bright light and darkness to manipulate the phase and/or amplitude of the circadian timing system. These insights and treatment approaches have direct applications in the design of countermeasures allowing astronauts to overcome some of the challenges which manned spaceflight poses for the human circadian timing system. We have conducted an operational feasibility study on the use of scheduled exposure to bright light and darkness prior to launch in order to facilitate adaptation of the circadian system of a NASA Space Shuttle crew to the altered sleep-wake schedule required for their mission. The results of this study illustrate how an understanding of the properties of the human circadian timing system and the consequences of circadian disruption can be applied to manned spaceflight.

Research on sleep, circadian rhythms and aging: applications to manned spaceflight.

PubMed

Czeisler, C A; Chiasera, A J; Duffy, J F

1991-01-01

Disorders of sleep and circadian rhythmicity are characteristic of both advancing age and manned spaceflight. Sleep fragmentation, reduced nocturnal sleep tendency and sleep efficiency, reduced daytime alertness, and increased daytime napping are common to both of these conditions. Recent research on the pathophysiology and treatment of disrupted sleep in older people has led to a better understanding of how the human circadian pacemaker regulates the timing of the daily sleep-wake cycle and how it responds to the periodic changes in the light-dark cycle to which we are ordinarily exposed. These findings have led to new treatments for some of the sleep disorders common to older individuals, using carefully timed exposure to bright light and darkness to manipulate the phase and/or amplitude of the circadian timing system. These insights and treatment approaches have direct applications in the design of countermeasures allowing astronauts to overcome some of the challenges which manned spaceflight poses for the human circadian timing system. We have conducted an operational feasibility study on the use of scheduled exposure to bright light and darkness prior to launch in order to facilitate adaptation of the circadian system of a NASA space shuttle crew to the altered sleep-wake schedule required for their mission. The results of this study illustrate how an understanding of the properties of the human circadian timing system and the consequences of circadian disruption can be applied to manned spaceflight.

Sleeping in Space: An Unexpected Challenge for Future Mars Explorers

NASA Technical Reports Server (NTRS)

Flynn-Evans, Erin

2018-01-01

This talk will serve as the keynote address for a research symposium being held at Washington State University. The purpose of the talk is to provide researchers and students at WSU with an overview about what it is like to sleep in space. Dr. Flynn-Evans will begin by highlighting how sleep is different in movies and science fiction compared to real life. She will next cover basic information about sleep and circadian rhythms, including how sleep works on earth. She will explain how people have circadian rhythms of different lengths and how the circadian clock has to be re-set each day. She will also describe how jet-lag works as an example of what happens during circadian misalignment. Dr. Flynn-Evans will also describe how sleep is different in space and will highlight the challenges that astronauts face in low-earth orbit. She will discuss how astronauts have a shorter sleep duration in space relative to on the ground and how their schedules can shift due to operational constraints. She will also describe how these issues affect alertness and performance. She will then discuss how sleep and scheduling may be different on a long-duration mission to Mars. She will discuss the differences in light and day length on earth and mars and illustrate how those differences pose significant challenges to sleep and circadian rhythms.

The influence of intermittent fasting on the circadian pattern of melatonin while controlling for caloric intake, energy expenditure, light exposure, and sleep schedules: A preliminary report.

PubMed

Almeneessier, Aljohara S; Bahammam, Ahmed S; Sharif, Munir M; Bahammam, Salman A; Nashwan, Samar Z; Pandi Perumal, Seithikurippu R; Cardinali, Daniel P; Alzoghaibi, Mohammad

2017-01-01

We hypothesized that if we control for food composition, caloric intake, light exposure, sleep schedule, and exercise, intermittent fasting would not influence the circadian pattern of melatonin. Therefore, we designed this study to assess the effect of intermittent fasting on the circadian pattern of melatonin. Eight healthy volunteers with a mean age of 26.6 ± 4.9 years and body mass index of 23.7 ± 3.5 kg/m 2 reported to the Sleep Disorders Center (the laboratory) on four occasions: (1) adaptation, (2) 4 weeks before Ramadan while performing Islamic intermittent fasting for 1 week (fasting outside Ramadan [FOR]), (3) 1 week before Ramadan (nonfasting baseline [BL]), and (4) during the 2 nd week of Ramadan while fasting ( Ramadan ). The plasma levels of melatonin were measured using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00 h. The light exposure, meal composition, energy expenditure, and sleep schedules remained the same while the participants stayed at the laboratory. The melatonin levels followed the same circadian pattern during the three monitoring periods (BL, FOR, and Ramadan ). The peak melatonin level was at 02:00 h and the trough level was at 11:00 h in all studied periods. Lower melatonin levels at 22:00 h were found during fasting compared to BL. Cosinor analysis revealed no significant changes in the acrophase of melatonin levels. In this preliminary report, under controlled conditions of light exposure, meal composition, energy expenditure, and sleep-wake schedules, intermittent fasting has no significant influence on the circadian pattern of melatonin.

The influence of intermittent fasting on the circadian pattern of melatonin while controlling for caloric intake, energy expenditure, light exposure, and sleep schedules: A preliminary report

PubMed Central

Almeneessier, Aljohara S.; Bahammam, Ahmed S.; Sharif, Munir M.; Bahammam, Salman A.; Nashwan, Samar Z.; Pandi Perumal, Seithikurippu R.; Cardinali, Daniel P.; Alzoghaibi, Mohammad

2017-01-01

AIMS: We hypothesized that if we control for food composition, caloric intake, light exposure, sleep schedule, and exercise, intermittent fasting would not influence the circadian pattern of melatonin. Therefore, we designed this study to assess the effect of intermittent fasting on the circadian pattern of melatonin. METHODS: Eight healthy volunteers with a mean age of 26.6 ± 4.9 years and body mass index of 23.7 ± 3.5 kg/m2 reported to the Sleep Disorders Center (the laboratory) on four occasions: (1) adaptation, (2) 4 weeks before Ramadan while performing Islamic intermittent fasting for 1 week (fasting outside Ramadan [FOR]), (3) 1 week before Ramadan (nonfasting baseline [BL]), and (4) during the 2nd week of Ramadan while fasting (Ramadan). The plasma levels of melatonin were measured using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00 h. The light exposure, meal composition, energy expenditure, and sleep schedules remained the same while the participants stayed at the laboratory. RESULTS: The melatonin levels followed the same circadian pattern during the three monitoring periods (BL, FOR, and Ramadan). The peak melatonin level was at 02:00 h and the trough level was at 11:00 h in all studied periods. Lower melatonin levels at 22:00 h were found during fasting compared to BL. Cosinor analysis revealed no significant changes in the acrophase of melatonin levels. CONCLUSIONS: In this preliminary report, under controlled conditions of light exposure, meal composition, energy expenditure, and sleep-wake schedules, intermittent fasting has no significant influence on the circadian pattern of melatonin. PMID:28808490

Self-Reported Recovery from 2-Week 12-Hour Shift Work Schedules: A 14-Day Follow-Up

PubMed Central

Merkus, Suzanne L.; Holte, Kari Anne; Huysmans, Maaike A.; van de Ven, Peter M.; van Mechelen, Willem; van der Beek, Allard J.

2015-01-01

Background Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work. Methods Sixty-one male offshore employees—20 night workers, 16 swing shift workers, and 25 day workers—rated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1–11) for 14 days after an offshore tour. After the two night-work schedules, differences on the 1st day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis. Results After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05–1.89) and swing shift workers (1.42, 95% confidence interval 1.03–1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found. Conclusion After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the 1st day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality. PMID:26929834

Sleep patterns and match performance in elite Australian basketball athletes.

PubMed

Staunton, Craig; Gordon, Brett; Custovic, Edhem; Stanger, Jonathan; Kingsley, Michael

2017-08-01

To assess sleep patterns and associations between sleep and match performance in elite Australian female basketball players. Prospective cohort study. Seventeen elite female basketball players were monitored across two consecutive in-season competitions (30 weeks). Total sleep time and sleep efficiency were determined using triaxial accelerometers for Baseline, Pre-match, Match-day and Post-match timings. Match performance was determined using the basketball efficiency statistic (EFF). The effects of match schedule (Regular versus Double-Header; Home versus Away) and sleep on EFF were assessed. The Double-Header condition changed the pattern of sleep when compared with the Regular condition (F (3,48) =3.763, P=0.017), where total sleep time Post-match was 11% less for Double-Header (mean±SD; 7.2±1.4h) compared with Regular (8.0±1.3h; P=0.007). Total sleep time for Double-Header was greater Pre-match (8.2±1.7h) compared with Baseline (7.1±1.6h; P=0.022) and Match-day (7.3±1.5h; P=0.007). Small correlations existed between sleep metrics at Pre-match and EFF for pooled data (r=-0.39 to -0.22; P≥0.238). Relationships between total sleep time and EFF ranged from moderate negative to large positive correlations for individual players (r=-0.37 to 0.62) and reached significance for one player (r=0.60; P=0.025). Match schedule can affect the sleep patterns of elite female basketball players. A large degree of inter-individual variability existed in the relationship between sleep and match performance; nevertheless, sleep monitoring might assist in the optimisation of performance for some athletes. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Review of Strategies for Treating Sleep Problems in Persons with Severe or Profound Mental Retardation or Multiple Handicaps.

ERIC Educational Resources Information Center

Lancioni, Giulio E.; O'Reilly, Mark F.; Basili, Gabriella

1999-01-01

A review of 14 studies on treatment strategies for sleep problems in individuals with severe mental retardation found the following treatments had been used: sleep scheduling, bedtime routine plus gradual distancing of parents, extinction, bedtime fading with or without response cost, chronotherapy, and melatonin. Results of treatments are…

Adolescents with greater mental toughness show higher sleep efficiency, more deep sleep and fewer awakenings after sleep onset.

PubMed

Brand, Serge; Gerber, Markus; Kalak, Nadeem; Kirov, Roumen; Lemola, Sakari; Clough, Peter J; Pühse, Uwe; Holsboer-Trachsler, Edith

2014-01-01

Mental toughness (MT) is understood as the display of confidence, commitment, challenge, and control. Mental toughness is associated with resilience against stress. However, research has not yet focused on the relation between MT and objective sleep. The aim of the present study was therefore to explore the extent to which greater MT is associated with objectively assessed sleep among adolescents. A total of 92 adolescents (35% females; mean age, 18.92 years) completed the Mental Toughness Questionnaire. Participants were split into groups of high and low mental toughness. Objective sleep was recorded via sleep electroencephalograms and subjective sleep was assessed via a questionnaire. Compared with participants with low MT, participants with high MT had higher sleep efficiency, a lower number of awakenings after sleep onset, less light sleep, and more deep sleep. They also reported lower daytime sleepiness. Adolescents reporting higher MT also had objectively better sleep, as recorded via sleep electroencephalograms. A bidirectional association between MT and sleep seems likely; therefore, among adolescence, improving sleep should increase MT, and improving MT should increase sleep. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Effects of Sleep Deprivation on U.S. Navy Watchstander Performance Onboard the Independence Class Littoral Combat Ship (LCS 2)

DTIC Science & Technology

2013-09-01

obtained .........................................................................8 Table 2. NPS theses relating to work schedule, sleep , and/or fatigue ...an analysis of performance issues related to sleep deprivation and fatigue aboard the Independence Class Littoral Combat Ship (LCS 2). The unique...rotation led to “fragmented sleep of generally less than 6 hours in duration.” Efforts to correct the issue of fatigue within the Navy were at a

Circadian countermeasures for shiftworkers during USMP-2: A report to mission management

NASA Technical Reports Server (NTRS)

Stewart, Karen T.; Hayes, Julie

1994-01-01

People who must work at night experience a number of physiological and psychological difficulties. These include sleepiness and fatigue at work, poor daytime sleep, gastrointestinal distress, impaired concentration and performance, disturbed mood, and increased health complaints and risk of disease. These difficulties arise because nocturnal work and daytime sleep take place at inappropriate phases of the body's circadian rhythms. Intense artificial light can shift the phase of human circadian rhythms, and can thus be used to promote adaptation to shifted work schedules. The first attempts to investigate the efficacy of light treatment for MSFC POCC shiftworkers took place during USML-1 and ATLAS-2. The findings from these studies led to the development of a Circadian Countermeasures Program that was implemented during USMP-2. Light treatment and other circadian countermeasures were employed to promote adjustment to mission shiftwork in POCC cadre volunteers. Treatment protocols were designed and customized for each volunteer's work hours and personal preferences. Treatment protocols included some or all of the following: scheduled self-administration of intense light, scheduled avoidance or attenuation of sunlight at other times, and sleep schedules. Data from post-mission questionnaires indicated that volunteers found the program to be effective, convenient, and beneficial.

2016 Rio Olympic Games: Can the schedule of events compromise athletes' performance?

PubMed

Rosa, João Paulo P; Rodrigues, Dayane F; Silva, Andressa; de Moura Simim, Mário Antônio; Costa, Varley T; Noce, Franco; de Mello, Marco Túlio

2016-01-01

The organizing committee of the 2016 Rio Olympic Games recently announced that some of the preliminary and final competitions will be held at night. The present article discusses the potential harmful effects of these late-night competitions on sleep, circadian rhythms and athletic performance during the Olympic Games. Specifically, night-time competition could lead to injury and may compromise an athlete's decision-making, attentional, physiological and other processes. Consequently, these impacts could negatively affect the performance of athletes and their teams. Thus, it is suggested that technical commissions take special care when creating strategies to minimize harm to the athletes by considering factors such as light exposure, melatonin intake, sleep hygiene and scheduled naps, and training at local competition time. Furthermore, it is necessary for specialists in chronobiology and sleep to engage with members of the national teams to develop an activity schedule for physical, technical, tactical and psychological preparation that accounts for circadian rhythms, thereby creating the best possible environment for the athletes to achieve their ideal performance.

Monitoring of the sleep patterns of shift workers in the automotive industry.

PubMed

Kawada, Tomoyuki; Shimizu, Takako; Kuratomi, Yushiro; Suto, Sachiko; Kanai, Tomoe; Nishime, Akemi; Nakano, Noriko

2011-01-01

The effect of shift schedules on the amount of sleep that workers receive is an important factor in workplace health and safety as well as the employees' overall quality of life. The objective of this study is to compare sleep period among workers engaging in each of the three-shift work. The amount of sleep (sleep period) that male workers with rotating shift schedules received was measured using accelerometers. The mean age of the 16 male workers enrolled in this study was 54.3 years (one standard deviation, 6.7 years). Thirteen participants ranged in age from 51 to 60 years of age, and the other three participants were 32, 48, and 50 years old. Work shifts were rotated on a weekly basis and were categorized into three periods: shift-1 (8:00 to 17:00), shift-2 (15:00 to 23:50), and shift-3 (23:30 to 8:15). Each work week consisted of 5 days. No significant differences were observed in the mean sleep period for each of the three shifts. However, the sleep periods during shift-1 or shift-2 tended to be longer than that obtained during shift-3. No effect of age on the length of the sleep period was observed. Rotating shift-work did not affect the amount of sleep that workers obtained. However, a comparison with previous study results suggests that morning shifts (starting at 6 AM) and day shifts (starting at 8 AM) may have different effects on sleep time.

Fatigue Management Strategies for the Stratospheric Observatory for Infrared Astronomy

NASA Technical Reports Server (NTRS)

Bendrick, Gregg

2012-01-01

Operation of the Stratospheric Observatory for Infrared Astronomy entails a great deal of night-time work, with the potential for both acute and chronic sleep loss, as well as circadian rhythm dysynchrony. Such fatigue can result in performance decrements, with an increased risk of operator error. The NASA Dryden Flight Research Center manages this fatigue risk by means of a layered approach, to include: 1) Education and Training 2) Work Schedule Scoring 3) Obtained Sleep Metrics 4) Workplace and Operational Mitigations and 5) Incident or Accident Investigation. Specifically, quantitative estimation of the work schedule score, as well as the obtained sleep metric, allows Supervisors and Managers to better manage the risk of fatigue within the context of mission requirements.

[Working time and sleep in nursing staff employed in "3 x 8" and "2 x 12" fast rotating shift schedules].

PubMed

Castellini, G; Anelli, M M; Punzi, S; Boari, P; Camerino, D; Costa, G

2011-01-01

The study is aimed at assessing, in 200 nurses shift workers, the impact on sleep of two different working areas ("emergency" and "hospitalization") having the same "3 x 8" shift system, and of two different shift schedules at quick rotation ("2 x 12" and "3 x 8") in the same working area ("emergency"). Night and morning shifts prove to interfere to a greater extent with sleep in relation to both "2 x 12" and "3 x 8" shift systems as well as to the two operative areas. Hence the importance to consider in shift work planning, the direction of shift rotation and the length of the duty period according to the type of activity.

Stress, Sleep and Recovery in Elite Soccer: A Critical Review of the Literature.

PubMed

Nédélec, Mathieu; Halson, Shona; Abaidia, Abd-Elbasset; Ahmaidi, Said; Dupont, Gregory

2015-10-01

In elite soccer, players are frequently exposed to various situations and conditions that can interfere with sleep, potentially leading to sleep deprivation. This article provides a comprehensive and critical review of the current available literature regarding the potential acute and chronic stressors (i.e., psychological, sociological and physiological stressors) placed on elite soccer players that may result in compromised sleep quantity and/or quality. Sleep is an essential part of the recovery process as it provides a number of important psychological and physiological functions. The effects of sleep disturbance on post-soccer match fatigue mechanisms and recovery time course are also described. Physiological and cognitive changes that occur when competing at night are often not conducive to sleep induction. Although the influence of high-intensity exercise performed during the night on subsequent sleep is still debated, environmental conditions (e.g., bright light in the stadium, light emanated from the screens) and behaviours related to evening soccer matches (e.g., napping, caffeine consumption, alcohol consumption) as well as engagement and arousal induced by the match may all potentially affect subsequent sleep. Apart from night soccer matches, soccer players are subjected to inconsistency in match schedules, unique team schedules and travel fatigue that may also contribute to the sleep debt. Sleep deprivation may be detrimental to the outcome of the recovery process after a match, resulting in impaired muscle glycogen repletion, impaired muscle damage repair, alterations in cognitive function and an increase in mental fatigue. The role of sleep in recovery is a complex issue, reinforcing the need for future research to estimate the quantitative and qualitative importance of sleep and to identify influencing factors. Efficient and individualised solutions are likely needed.

Later school start time is associated with improved sleep and daytime functioning in adolescents.

PubMed

Boergers, Julie; Gable, Christopher J; Owens, Judith A

2014-01-01

Chronic insufficient sleep is a growing concern among adolescents and is associated with a host of adverse health consequences. Early school start times may be an environmental contributor to this problem. The purpose of this study was to examine the impact of a delay in school start time on sleep patterns, sleepiness, mood, and health-related outcomes. Boarding students (n = 197, mean age = 15.6 yr) attending an independent high school completed the School Sleep Habits Survey before and after the school start time was experimentally delayed from 8:00 a.m. to 8:25 a.m. The delay in school start time was associated with a significant (29 min) increase in sleep duration on school nights. The percentage of students receiving 8 or more hours of sleep on a school night increased to more than double, from 18% to 44%. Students in 9th and 10th grade and those with lower baseline sleep amounts were more likely to report improvements in sleep duration after the schedule change. Daytime sleepiness, depressed mood, and caffeine use were all significantly reduced after the delay in school start time. Sleep duration reverted to baseline levels when the original (earlier) school start time was reinstituted. A modest (25 min) delay in school start time was associated with significant improvements in sleep duration, daytime sleepiness, mood, and caffeine use. These findings have important implications for public policy and add to research suggesting the health benefits of modifying school schedules to more closely align with adolescents' circadian rhythms and sleep needs.

Intermittent fasting during Ramadan: does it affect sleep?

PubMed

Bahammam, Ahmed S; Almushailhi, Khalid; Pandi-Perumal, Seithikurippu R; Sharif, Munir M

2014-02-01

Islamic intermittent fasting is distinct from regular voluntary or experimental fasting. We hypothesised that if a regimen of a fixed sleep-wake schedule and a fixed caloric intake is followed during intermittent fasting, the effects of fasting on sleep architecture and daytime sleepiness will be minimal. Therefore, we designed this study to objectively assess the effects of Islamic intermittent fasting on sleep architecture and daytime sleepiness. Eight healthy volunteers reported to the Sleep Disorders Centre on five occasions for polysomnography and multiple sleep latency tests: (1) during adaptation; (2) 3 weeks before Ramadan, after having performed Islamic fasting for 1 week (baseline fasting); (3) 1 week before Ramadan (non-fasting baseline); (4) 2 weeks into Ramadan (Ramadan); and (5) 2 weeks after Ramadan (non-fasting; Recovery). Daytime sleepiness was assessed using the Epworth Sleepiness Scale and the multiple sleep latency test. The participants had a mean age of 26.6 ± 4.9 years, a body mass index of 23.7 ± 3.5 kg m(-2) and an Epworth Sleepiness Scale score of 7.3 ± 2.7. There was no change in weight or the Epworth Sleepiness Scale in the four study periods. The rapid eye movement sleep percentage was significantly lower during fasting. There was no difference in sleep latency, non-rapid eye movement sleep percentage, arousal index and sleep efficiency. The multiple sleep latency test analysis revealed no difference in the sleep latency between the 'non-fasting baseline', 'baseline fasting', 'Ramadan' and 'Recovery' time points. Under conditions of a fixed sleep-wake schedule and a fixed caloric intake, Islamic intermittent fasting results in decreased rapid eye movement sleep with no impact on other sleep stages, the arousal index or daytime sleepiness. © 2013 European Sleep Research Society.

Prevalence and Correlates of Insufficient Sleep Syndrome in Japanese Young Adults: A Web-Based Cross-Sectional Study.

PubMed

Morita, Yuko; Sasai-Sakuma, Taeko; Asaoka, Shoichi; Inoue, Yuichi

2015-10-15

This study investigated the prevalence and risk factors of insufficient sleep syndrome (ISS), and factors associated with daytime dysfunction in the disorder in Japanese young adults. In this cross-sectional study, a web-based questionnaire survey was used to assess demographic variables, sleep habits and quality, depressive symptoms, and health-related quality of life (HRQOL) in 2,276 participants aged 20-25. Eleven percent of participants were classified as having ISS. Multiple logistic regression analysis revealed that the presence of ISS was significantly associated with social status (student or full-time employee). The participants with ISS had significantly higher depression scores and lower mental component summary scores than healthy sleepers. In the participants with ISS, a delayed sleep-wake schedule was extracted as a factor associated with worse mental component summary. Results indicate a relatively high proportion of Japanese young adults suffer from ISS, and that the condition is associated with a social status of student or full-time employee. Moreover, a delayed sleep-wake schedule may lead to further deterioration of mental HRQOL in ISS-affected persons. © 2015 American Academy of Sleep Medicine.

Using the principles of circadian physiology enhances shift schedule design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Connolly, J.J.; Moore-Ede, M.C.

1987-01-01

Nuclear power plants must operate 24 h, 7 days a week. For the most part, shift schedules currently in use at nuclear power plants have been designed to meet operational needs without considering the biological clocks of the human operators. The development of schedules that also take circadian principles into account is a positive step that can be taken to improve plant safety by optimizing operator alertness. These schedules reduce the probability of human errors especially during backshifts. In addition, training programs that teach round-the-clock workers how to deal with the problems of shiftwork can help to optimize performance andmore » alertness. These programs teach shiftworkers the underlying causes of the sleep problems associated with shiftwork and also provide coping strategies for improving sleep and dealing with the transition between shifts. When these training programs are coupled with an improved schedule, the problems associated with working round-the-clock can be significantly reduced.« less

Effects of sleep schedules on commercial motor vehicle driver performance : part 1

DOT National Transportation Integrated Search

2000-09-01

The Federal Motor Carrier Safety Administration sponsored a study to gather and analyze data on commercial motor vehicle (CMV) driver rest and recovery cycles, effects of partial sleep deprivation, and prediction of subsequent performance. The study ...

Effects of sleep schedules on commercial motor vehicle driver performance : part 2

DOT National Transportation Integrated Search

2000-09-01

The Federal Motor Carrier Safety Administration sponsored a study to gather and analyze data on commercial motor vehicle driver rest and recovery cycles, effects of partial sleep deprivation, and prediction of subsequent performance. The study began ...

Sleep-wake cycle in young and older persons with a lifetime history of mood disorders.

PubMed

Robillard, Rébecca; Naismith, Sharon L; Smith, Kristie Leigh; Rogers, Naomi L; White, Django; Terpening, Zoe; Ip, Tony K C; Hermens, Daniel F; Whitwell, Bradley; Scott, Elizabeth M; Hickie, Ian B

2014-01-01

Considering the marked changes in sleep and circadian rhythms across the lifespan, age may contribute to the heterogeneity in sleep-wake profiles linked to mood disorders. This study aimed to investigate the contributions of age and depression severity to sleep-wake disturbances. The Hamilton Depression Rating Scale (HDRS) was administered to assess current symptoms severity in 238 persons with a history of a mood disorder between 12 and 90 years of age (y.o.). Actigraphy was recorded over five to 22 days. Regression analyses and analyses of variance [age (12-19 y.o., 20-39 y.o., 40-59 y.o., and ≥ 60 y.o.) by depression severity (HDRS< and ≥ 8)] were conducted. The 12-19 y.o. and 20-39 y.o. groups had a delayed sleep schedule and acrophase compared to all other groups. The ≥ 60 y.o. group had a lower rhythmicity and amplitude (p ≤ .006) than the 12-19 y.o. group (p ≤ .046). Participants with a HDRS ≥ 8 spent longer time in bed, had later sleep offset times and had lower circadian rhythmicity than those with a HDRS<8 (p ≤ .036). Younger age and higher HDRS score correlated with later sleep onset and offset times, longer time in bed, higher WASO, lower sleep efficiency and later acrophase (p ≤ .023). Age was a significant predictor of delayed sleep and activity schedules (p ≤ .001). The profile of sleep-wake cycle disturbances associated with mood disorders changes with age, with prominent sleep phase delay during youth and reduced circadian strength in older persons. Conversely, disruptions in sleep consolidation seem more stable across age.

Association between symptoms and subtypes of attention-deficit hyperactivity disorder and sleep problems/disorders.

PubMed

Chiang, Huey-Ling; Gau, Susan Shur-Fen; Ni, Hsing-Chang; Chiu, Yen-Nan; Shang, Chi-Yung; Wu, Yu-Yu; Lin, Liang-Ying; Tai, Yueh-Ming; Soong, Wei-Tsuen

2010-12-01

This study aimed to investigate the association between attention-deficit hyperactivity disorder (ADHD) symptoms and subtypes, and sleep schedules, daytime inadvertent napping, and sleep problems/disorders in children and adolescents with and without ADHD. The sample included 325 patients with ADHD, aged 10-17 years [male: 81.5%; combined type (ADHD-C): 174; predominantly inattentive type (ADHD-I): 130; predominantly hyperactive-impulsive type (ADHD-HI): 21], and 257 children and adolescents without lifetime ADHD (non-ADHD). We conducted psychiatric interviews with the participants and their mothers before making the diagnoses of ADHD, other psychiatric disorders, and sleep problems or disorders. We also collected the medication treatment data and parent and teacher reports of ADHD symptoms. Multi-level models were used for data analyses controlling for sex, age, psychiatric comorbidities, and treatment with methylphenidate. The ADHD-C and ADHD-I groups had more daytime inadvertent napping. In general, the three subtypes were associated with increased rates of sleep problems/disorders. Specifically, ADHD-C rather than ADHD-I was associated with circadian rhythm problems, sleep-talking, nightmares (also ADHD-HI), and ADHD-I was associated with hypersomnia. The most-related sleep schedules and problems for inattention and hyperactivity-impulsivity were earlier bedtime, later rise time, longer nocturnal sleep, more frequent daytime napping, insomnia, sleep terrors, sleep-talking, snoring, and bruxism across informants. The findings imply that in addition to the dichotomous approach of ADHD and considering the psychiatric comorbid conditions, ADHD subtypes and symptom dimensions need to be considered in clinical practice and in the research regarding the association between ADHD and sleep problems/disorders. © 2010 European Sleep Research Society.

Work and Sleep--A Prospective Study of Psychosocial Work Factors, Physical Work Factors, and Work Scheduling.

PubMed

Åkerstedt, Torbjörn; Garefelt, Johanna; Richter, Anne; Westerlund, Hugo; Magnusson Hanson, Linda L; Sverke, Magnus; Kecklund, Göran

2015-07-01

There is limited knowledge about the prospective relationship between major work characteristics (psychosocial, physical, scheduling) and disturbed sleep. The current study sought to provide such knowledge. Prospective cohort, with measurements on two occasions (T1 and T2) separated by two years. Naturalistic study, Sweden. There were 4,827 participants forming a representative sample of the working population. Questionnaire data on work factors obtained on two occasions were analyzed with structural equation modeling. Competing models were compared in order to investigate temporal relationships. A reciprocal model was found to fit the data best. Sleep disturbances at T2 were predicted by higher work demands at T1 and by lower perceived stress at T1. In addition, sleep disturbances at T1 predicted subsequent higher perception of stress, higher work demands, lower degree of control, and less social support at work at T2. A cross-sectional mediation analysis showed that (higher) perceived stress mediated the relationship between (higher) work demands and sleep disturbances; however, no such association was found longitudinally. Higher work demands predicted disturbed sleep, whereas physical work characteristics, shift work, and overtime did not. In addition, disturbed sleep predicted subsequent higher work demands, perceived stress, less social support, and lower degree of control. The results suggest that remedial interventions against sleep disturbances should focus on psychosocial factors, and that such remedial interventions may improve the psychosocial work situation in the long run. © 2015 Associated Professional Sleep Societies, LLC.

Association between reported sleep need and sleepiness at the wheel: comparative study on French highways between 1996 and 2011.

PubMed

Quera-Salva, M A; Hartley, S; Sauvagnac-Quera, R; Sagaspe, P; Taillard, J; Contrand, B; Micoulaud, J A; Lagarde, E; Barbot, F; Philip, P

2016-12-21

To investigate the evolution over 15 years of sleep schedules, sleepiness at the wheel and driving risk among highway drivers. Comparative survey including questions on usual sleep schedules and before the trip, sleepiness at the wheel, the Epworth sleepiness scale, Basic Nordic Sleep Questionnaire (BNSQ) and a travel questionnaire. 80% of drivers stopped by the highway patrol agreed to participate in both studies with a total of 3545 drivers in 2011 and 2196 drivers in 1996 interviewed. After standardisation based on sex, age and mean annual driving distance, drivers in 2011 reported shorter sleep time on week days (p<0.0001), and week-ends (p<0.0001) and shorter optimal sleep time (p<0.0001) compared to 1996 drivers. There were more drivers sleepy at the wheel in 2011 than in 1996 (p<0.0001) and 2.5 times more drivers in 2011 than in 1996 had an Epworth sleepiness score >15 indicating severe sleepiness. Even if drivers in 2011 reported good sleep hygiene prior to a highway journey, drivers have reduced their mean weekly sleep duration over 15 years and have a higher risk of sleepiness at the wheel. Sleep hygiene for automobile drivers remains an important concept to address. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Circadian temperature and melatonin rhythms, sleep, and neurobehavioral function in humans living on a 20-h day

NASA Technical Reports Server (NTRS)

Wyatt, J. K.; Ritz-De Cecco, A.; Czeisler, C. A.; Dijk, D. J.

1999-01-01

The interaction of homeostatic and circadian processes in the regulation of waking neurobehavioral functions and sleep was studied in six healthy young subjects. Subjects were scheduled to 15-24 repetitions of a 20-h rest/activity cycle, resulting in desynchrony between the sleep-wake cycle and the circadian rhythms of body temperature and melatonin. The circadian components of cognitive throughput, short-term memory, alertness, psychomotor vigilance, and sleep disruption were at peak levels near the temperature maximum, shortly before melatonin secretion onset. These measures exhibited their circadian nadir at or shortly after the temperature minimum, which in turn was shortly after the melatonin maximum. Neurobehavioral measures showed impairment toward the end of the 13-h 20-min scheduled wake episodes. This wake-dependent deterioration of neurobehavioral functions can be offset by the circadian drive for wakefulness, which peaks in the latter half of the habitual waking day during entrainment. The data demonstrate the exquisite sensitivity of many neurobehavioral functions to circadian phase and the accumulation of homeostatic drive for sleep.

The efficacy of a restart break for recycling with optimal performance depends critically on circadian timing.

PubMed

Van Dongen, Hans P A; Belenky, Gregory; Vila, Bryan J

2011-07-01

Under simulated shift-work conditions, we investigated the efficacy of a restart break for maintaining neurobehavioral functioning across consecutive duty cycles, as a function of the circadian timing of the duty periods. As part of a 14-day experiment, subjects underwent two cycles of five simulated daytime or nighttime duty days, separated by a 34-hour restart break. Cognitive functioning and high-fidelity driving simulator performance were tested 4 times per day during the two duty cycles. Lapses on a psychomotor vigilance test (PVT) served as the primary outcome variable. Selected sleep periods were recorded polysomnographically. The experiment was conducted under standardized, controlled laboratory conditions with continuous monitoring. Twenty-seven healthy adults (13 men, 14 women; aged 22-39 years) participated in the study. Subjects were randomly assigned to a nighttime duty (experimental) condition or a daytime duty (control) condition. The efficacy of the 34-hour restart break for maintaining neurobehavioral functioning from the pre-restart duty cycle to the post-restart duty cycle was compared between these two conditions. Relative to the daytime duty condition, the nighttime duty condition was associated with reduced amounts of sleep, whereas sleep latencies were shortened and slow-wave sleep appeared to be conserved. Neurobehavioral performance measures ranging from lapses of attention on the PVT to calculated fuel consumption on the driving simulators remained optimal across time of day in the daytime duty schedule, but degraded across time of night in the nighttime duty schedule. The 34-hour restart break was efficacious for maintaining PVT performance and other objective neurobehavioral functioning profiles from one duty cycle to the next in the daytime duty condition, but not in the nighttime duty condition. Subjective sleepiness did not reliably track objective neurobehavioral deficits. The 34-hour restart break was adequate for maintaining performance in the case of optimal circadian placement of sleep and duty periods (control condition) but was inadequate (and perhaps even detrimental) for maintaining performance in a simulated nighttime duty schedule (experimental condition). Current US transportation hours-of-service regulations mandate time off duty but do not consider the circadian aspects of shift scheduling. Reinforcing a recent trend of applying sleep science to inform policymaking for duty and rest times, our findings indicate that restart provisions in hours-of-service regulations could be improved by taking the circadian timing of the duty schedules into account.

Prescribed Travel Schedules for Fatigue Management

NASA Technical Reports Server (NTRS)

Whitmire, Alexandra; Johnston, Smith; Lockley, Steven

2011-01-01

The NASA Fatigue Management Team is developing recommendations for managing fatigue during travel and for shift work operations, as Clinical Practice Guidelines for the Management of Circadian Desynchrony in ISS Operations. The Guidelines provide the International Space Station (ISS ) flight surgeons and other operational clinicians with evidence-based recommendations for mitigating fatigue and other factors related to sleep loss and circadian desynchronization. As much international travel is involved both before and after flight, the guidelines provide recommendations for: pre-flight training, in-flight operations, and post-flight rehabilitation. The objective of is to standardize the process by which care is provided to crewmembers, ground controllers, and other support personnel such as trainers, when overseas travel or schedule shifting is required. Proper scheduling of countermeasures - light, darkness, melatonin, diet, exercise, and medications - is the cornerstone for facilitating circadian adaptation, improving sleep, enhancing alertness, and optimizing performance. The Guidelines provide, among other things, prescribed travel schedules that outline the specific implementation of these mitigation strategies. Each travel schedule offers evidence based protocols for properly using the NASA identified countermeasures for fatigue. This presentation will describe the travel implementation schedules and how these can be used to alleviate the effects of jet lag and/or schedule shifts.

Influence of sleep and meal schedules on performance peaks in competitive sprinters.

PubMed

Javierre, C; Calvo, M; Díez, A; Garrido, E; Segura, R; Ventura, J L

1996-08-01

The influence of sleep and meal schedules on performance in short distance running was assessed in a group of 8 national-class competition male sprinters. They were tested on Saturdays for five consecutive weeks. On each testing day, the performance time for an 80 m sprint was registered on eight different occasions during days 1 and 4, on 9 occasions on days 2 and 5, and on 7 occasions on day 3. On control days (days 1 and 4) performance gradually improved during the morning up to 13:00 h, decreased at 15:00 h, and again improved thereafter, with a maximum peak performance at 19:00 h. On day 2, in which sleep/wake cycles and meal-times were advanced for two hours, and on day 3, in which timetables were delayed for two hours, maximum peak performance was observed at 17:00 h and 21:00 h, respectively. At the time of maximum peak performance on both days a statistically significant improvement was observed as compared with the control day (day 2, p < 0.01; day 3, p = 0.001). On day 5, in which only the sleep/wake cycle was advanced for two hours, performance in the afternoon and evening was similar to that recorded on days 1 and 4. We observed that easy manipulation of sleep and meal schedules would allow competitive sprinters to synchronize peak power output with the time of the athletic event, increasing the chances for improvement in performance.

Shift work and the assessment and management of shift work disorder (SWD).

PubMed

Wright, Kenneth P; Bogan, Richard K; Wyatt, James K

2013-02-01

Nearly 20% of the labor force worldwide, work shifts that include work hours outside 07:00 h to 18:00 h. Shift work is common in many occupations that directly affect the health and safety of others (e.g., protective services, transportation, healthcare), whereas quality of life, health, and safety during shift work and the commute home can affect workers in any field. Increasing evidence indicates that shift-work schedules negatively influence worker physiology, health, and safety. Shift work disrupts circadian sleep and alerting cycles, resulting in disturbed daytime sleep and excessive sleepiness during the work shift. Moreover, shift workers are at risk for shift work disorder (SWD). This review focuses on shift work and the assessment and management of sleepiness and sleep disruption associated with shift work schedules and SWD. Management strategies include approaches to promote sleep, wakefulness, and adaptation of the circadian clock to the imposed work schedule. Additional studies are needed to further our understanding of the mechanisms underlying the health risks of shift work, understanding which shift workers are at most risk of SWD, to investigate treatment options that address the health and safety burdens associated with shift work and SWD, and to further develop and assess the comparative effectiveness of countermeasures and treatment options. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Unified Model of Performance for Predicting the Effects of Sleep and Caffeine.

PubMed

Ramakrishnan, Sridhar; Wesensten, Nancy J; Kamimori, Gary H; Moon, James E; Balkin, Thomas J; Reifman, Jaques

2016-10-01

Existing mathematical models of neurobehavioral performance cannot predict the beneficial effects of caffeine across the spectrum of sleep loss conditions, limiting their practical utility. Here, we closed this research gap by integrating a model of caffeine effects with the recently validated unified model of performance (UMP) into a single, unified modeling framework. We then assessed the accuracy of this new UMP in predicting performance across multiple studies. We hypothesized that the pharmacodynamics of caffeine vary similarly during both wakefulness and sleep, and that caffeine has a multiplicative effect on performance. Accordingly, to represent the effects of caffeine in the UMP, we multiplied a dose-dependent caffeine factor (which accounts for the pharmacokinetics and pharmacodynamics of caffeine) to the performance estimated in the absence of caffeine. We assessed the UMP predictions in 14 distinct laboratory- and field-study conditions, including 7 different sleep-loss schedules (from 5 h of sleep per night to continuous sleep loss for 85 h) and 6 different caffeine doses (from placebo to repeated 200 mg doses to a single dose of 600 mg). The UMP accurately predicted group-average psychomotor vigilance task performance data across the different sleep loss and caffeine conditions (6% < error < 27%), yielding greater accuracy for mild and moderate sleep loss conditions than for more severe cases. Overall, accounting for the effects of caffeine resulted in improved predictions (after caffeine consumption) by up to 70%. The UMP provides the first comprehensive tool for accurate selection of combinations of sleep schedules and caffeine countermeasure strategies to optimize neurobehavioral performance. © 2016 Associated Professional Sleep Societies, LLC.

Sleep and circadian rhythms in four orbiting astronauts.

PubMed

Monk, T H; Buysse, D J; Billy, B D; Kennedy, K S; Willrich, L M

1998-06-01

This experiment measured the sleep and circadian rhythms of four male astronauts aboard a space shuttle (STS-78) orbiting the Earth for 17 days. The space mission was specially scheduled to minimize disruptions in circadian rhythms and sleep so that the effects of space flight and microgravity per se could be studied. Data were collected in 72-h measurement blocks: one block 7 days before launch, one early within the mission (3 days after launch), one late in the mission (12 days after launch), and one 18 days after landing. Within each measurement block, all sleep was recorded both polysomnographically and by sleep diary. Core body temperature was sampled every 6 mins. Actillumes were worn continuously. All urine samples were collected separately. Performance was assessed by a computerized test battery (3/day) and by end-of-shift questionnaires (1/day); mood and alertness were measured by visual analogue scales (5/day). Circadian rhythms in orbit appeared to be very similar in phase and amplitude to those on the ground, and were appropriately aligned for the required work/rest schedule. There was no change from early flight to late flight. This was also reflected in mood, alertness, and performance scores, which were satisfactory at both in-flight time points. However, in-flight sleep showed a decreased amount of sleep obtained (mean = 6.1 h), and all four astronauts showed a decrease in delta sleep. No further degradation in sleep was seen when early flight was compared to late flight, and no other sleep parameters showed reliable trends.

The dim light melatonin onset following fixed and free sleep schedules.

PubMed

Burgess, Helen J; Eastman, Charmane I

2005-09-01

The time at which the dim light melatonin onset (DLMO) occurs can be used to ensure the correct timing of light and/or melatonin administration in order to produce desired circadian phase shifts. Sometimes however, measuring the DLMO is not feasible. Here we determined if the DLMO was best estimated from fixed sleep times (based on habitual sleep times) or free (ad libitum) sleep times. Young healthy sleepers on fixed (n=60) or free (n=60) sleep schedules slept at home for 6 days. Sleep times were recorded with sleep logs verified with wrist actigraphy. Half-hourly saliva samples were then collected during a dim light phase assessment and were later assayed to determine the DLMO. We found that the DLMO was more highly correlated with sleep times in the free sleepers than in the fixed sleepers (DLMO versus wake time, r=0.70 and r=0.44, both P<0.05). The regression equation between wake time and the DLMO in the free sleepers predicted the DLMO in an independent sample of free sleepers (n=23) to within 1.5 h of the actual DLMO in 96% of cases. These results indicate that the DLMO can be readily estimated in people whose sleep times are minimally affected by work, class and family commitments. Further work is necessary to determine if the DLMO can be accurately estimated in people with greater work and family responsibilities that affect their sleep times, perhaps by using weekend wake times, and if this method will apply to the elderly and patients with circadian rhythm disorders.

The dim light melatonin onset following fixed and free sleep schedules

PubMed Central

Burgess, Helen J.; Eastman, Charmane I.

2013-01-01

Summary The time at which the dim light melatonin onset (DLMO) occurs can be used to ensure the correct timing of light and/or melatonin administration in order to produce desired circadian phase shifts. Sometimes however, measuring the DLMO is not feasible. Here we determined if the DLMO was best estimated from fixed sleep times (based on habitual sleep times) or free (ad libitum) sleep times. Young healthy sleepers on fixed (n = 60) or free (n = 60) sleep schedules slept at home for 6 days. Sleep times were recorded with sleep logs verified with wrist actigraphy. Half-hourly saliva samples were then collected during a dim light phase assessment and were later assayed to determine the DLMO. We found that the DLMO was more highly correlated with sleep times in the free sleepers than in the fixed sleepers (DLMO versus wake time, r = 0.70 and r = 0.44, both P < 0.05). The regression equation between wake time and the DLMO in the free sleepers predicted the DLMO in an independent sample of free sleepers (n = 23) to within 1.5 h of the actual DLMO in 96% of cases. These results indicate that the DLMO can be readily estimated in people whose sleep times are minimally affected by work, class and family commitments. Further work is necessary to determine if the DLMO can be accurately estimated in people with greater work and family responsibilities that affect their sleep times, perhaps by using weekend wake times, and if this method will apply to the elderly and patients with circadian rhythm disorders. PMID:16120097

U.S. Laboratory

NASA Image and Video Library

2016-03-23

ISS047e016355 (03/23/2016) --- The International Space Station's Destiny Laboratory at “night” shortly before the Expedition 47 crew entered its scheduled sleep period. The space station experiences 16 sunrises and sunsets every day which can alter the crew’s circadian rhythm and disrupt sleep patterns. Lights are turned off and windows are covered to give the interior of the station a nighttime environment during sleep cycles.

Power Aware Distributed Systems

DTIC Science & Technology

2004-01-01

detection or threshold functions to trigger the main CPU. The main processor can sleep and either wakeup on a schedule or by a positive threshold event...the RTOS must determine if wake-up latency can be tolerated (or, if it could be hidden by pre- wakeup ). The prediction accuracy for scheduling ...and processor shutdown/ wakeup . This analysis can be used to accurately analyze the schedulability of non-concrete periodic task sets, scheduled using

An on-time power-aware scheduling scheme for medical sensor SoC-based WBAN systems.

PubMed

Hwang, Tae-Ho; Kim, Dong-Sun; Kim, Jung-Guk

2012-12-27

The focus of many leading technologies in the field of medical sensor systems is on low power consumption and robust data transmission. For example, the implantable cardioverter-defibrillator (ICD), which is used to maintain the heart in a healthy state, requires a reliable wireless communication scheme with an extremely low duty-cycle, high bit rate, and energy-efficient media access protocols. Because such devices must be sustained for over 5 years without access to battery replacement, they must be designed to have extremely low power consumption in sleep mode. Here, an on-time, energy-efficient scheduling scheme is proposed that performs power adjustments to minimize the sleep-mode current. The novelty of this scheduler is that it increases the determinacy of power adjustment and the predictability of scheduling by employing non-pre-emptible dual priority scheduling. This predictable scheduling also guarantees the punctuality of important periodic tasks based on their serialization, by using their worst case execution time) and the power consumption optimization. The scheduler was embedded into a system on chip (SoC) developed to support the wireless body area network-a wakeup-radio and wakeup-timer for implantable medical devices. This scheduling system is validated by the experimental results of its performance when used with life-time extensions of ICD devices.

An On-Time Power-Aware Scheduling Scheme for Medical Sensor SoC-Based WBAN Systems

PubMed Central

Hwang, Tae-Ho; Kim, Dong-Sun; Kim, Jung-Guk

2013-01-01

The focus of many leading technologies in the field of medical sensor systems is on low power consumption and robust data transmission. For example, the implantable cardioverter-defibrillator (ICD), which is used to maintain the heart in a healthy state, requires a reliable wireless communication scheme with an extremely low duty-cycle, high bit rate, and energy-efficient media access protocols. Because such devices must be sustained for over 5 years without access to battery replacement, they must be designed to have extremely low power consumption in sleep mode. Here, an on-time, energy-efficient scheduling scheme is proposed that performs power adjustments to minimize the sleep-mode current. The novelty of this scheduler is that it increases the determinacy of power adjustment and the predictability of scheduling by employing non-pre-emptible dual priority scheduling. This predictable scheduling also guarantees the punctuality of important periodic tasks based on their serialization, by using their worst case execution time) and the power consumption optimization. The scheduler was embedded into a system on chip (SoC) developed to support the wireless body area network—a wakeup-radio and wakeup-timer for implantable medical devices. This scheduling system is validated by the experimental results of its performance when used with life-time extensions of ICD devices. PMID:23271602

Skylab sleep monitoring experiment (experiment M133)

NASA Technical Reports Server (NTRS)

Frost, J. D., Jr.

1975-01-01

A summary of the conceptual design of the Skylab sleep monitoring experiment and a comprehensive compilation of the data-analysis results from the three Skylab missions is presented. One astronaut was studied per flight, electroencephalographic, electro-oculographic, and headmotion signals acquired during sleep by use of an elastic recording cap containing sponge electrodes and an attached miniature preamplifier/accelerometer unit are shown. A control-panel assembly, mounted in the sleep compartment, tested electrodes, preserved analog signals, and automatically analyzed data in real time (providing a telemetered indication of sleep stage). Results indicate that men are able to obtain adequate sleep in regularly scheduled eight-hour rest periods during extended space missions.

Sleep in athletes and the effects of Ramadan.

PubMed

Roky, Rachida; Herrera, Christopher Paul; Ahmed, Qanta

2012-01-01

Sleep is now considered as a new frontier in performance enhancement. This article presents background content on sleep function, sleep needs and methods of sleep investigation along with data on the potential effects of Ramadan fasting on sleep in normal individuals and athletes. Accumulated sleep loss has negative impacts on cognitive function, mood, daytime sleepiness and performance. Sleep studies in athletes fasting during Ramadan are very rare. Most of them have demonstrated that during this month, sleep duration decreased and sleep timing shifted. But the direct relation between sleep changes and performance during Ramadan is not yet elucidated. Objective sleep patterns can be investigated using polysomnography, actigraphy, and standardised questionnaires and recorded in daily journals or sleep logs. The available data on sleep indicate that team doctors and coaches should consider planning sleep schedule and napping; implementing educational programmes focusing on the need for healthy sleep; and consider routine screening for sleep loss in athletes of all age groups and genders.

Positive affect and sleep in spousal Alzheimer caregivers: a longitudinal study.

PubMed

von Känel, Roland; Mausbach, Brent T; Ancoli-Israel, Sonia; Mills, Paul J; Dimsdale, Joel E; Patterson, Thomas L; Grant, Igor

2014-09-03

This article examines the longitudinal relation between positive affect (PA) and sleep in 126 spousal Alzheimer's disease caregivers. Caregivers underwent 4 yearly assessments for the Positive and Negative Affect Schedule, the self-rated Pittsburgh Sleep Quality Index, and actigraphy to objectify nighttime total sleep time, wake after sleep onset, and percentage of sleep. Increased levels of PA and a greater positivity (i.e., positive-to-negative affect) ratio were significantly associated with better subjective sleep over the entire study period. Yearly increases in PA-even when controlling for negative affect (NA)-and in the positivity ratio were also associated with better subjective sleep. PA and actigraphy measures showed no significant relations. Increased PA is longitudinally associated with better sleep in dementia caregivers largely independent of NA.

A Unified Model of Performance for Predicting the Effects of Sleep and Caffeine

PubMed Central

Ramakrishnan, Sridhar; Wesensten, Nancy J.; Kamimori, Gary H.; Moon, James E.; Balkin, Thomas J.; Reifman, Jaques

2016-01-01

Study Objectives: Existing mathematical models of neurobehavioral performance cannot predict the beneficial effects of caffeine across the spectrum of sleep loss conditions, limiting their practical utility. Here, we closed this research gap by integrating a model of caffeine effects with the recently validated unified model of performance (UMP) into a single, unified modeling framework. We then assessed the accuracy of this new UMP in predicting performance across multiple studies. Methods: We hypothesized that the pharmacodynamics of caffeine vary similarly during both wakefulness and sleep, and that caffeine has a multiplicative effect on performance. Accordingly, to represent the effects of caffeine in the UMP, we multiplied a dose-dependent caffeine factor (which accounts for the pharmacokinetics and pharmacodynamics of caffeine) to the performance estimated in the absence of caffeine. We assessed the UMP predictions in 14 distinct laboratory- and field-study conditions, including 7 different sleep-loss schedules (from 5 h of sleep per night to continuous sleep loss for 85 h) and 6 different caffeine doses (from placebo to repeated 200 mg doses to a single dose of 600 mg). Results: The UMP accurately predicted group-average psychomotor vigilance task performance data across the different sleep loss and caffeine conditions (6% < error < 27%), yielding greater accuracy for mild and moderate sleep loss conditions than for more severe cases. Overall, accounting for the effects of caffeine resulted in improved predictions (after caffeine consumption) by up to 70%. Conclusions: The UMP provides the first comprehensive tool for accurate selection of combinations of sleep schedules and caffeine countermeasure strategies to optimize neurobehavioral performance. Citation: Ramakrishnan S, Wesensten NJ, Kamimori GH, Moon JE, Balkin TJ, Reifman J. A unified model of performance for predicting the effects of sleep and caffeine. SLEEP 2016;39(10):1827–1841. PMID:27397562

Class start times, sleep, and academic performance in college: a path analysis.

PubMed

Onyper, Serge V; Thacher, Pamela V; Gilbert, Jack W; Gradess, Samuel G

2012-04-01

Path analysis was used to examine the relationship between class start times, sleep, circadian preference, and academic performance in college-aged adults. Consistent with observations in middle and high school students, college students with later class start times slept longer, experienced less daytime sleepiness, and were less likely to miss class. Chronotype was an important moderator of sleep schedules and daytime functioning; those with morning preference went to bed and woke up earlier and functioned better throughout the day. The benefits of taking later classes did not extend to academic performance, however; grades were somewhat lower in students with predominantly late class schedules. Furthermore, students taking later classes were at greater risk for increased alcohol consumption, and among all the factors affecting academic performance, alcohol misuse exerted the strongest effect. Thus, these results indicate that later class start times in college, while allowing for more sleep, also increase the likelihood of alcohol misuse, ultimately impeding academic success.

Surveying the Impact of Work Hours and Schedules on Commercial Motor Vehicle Driver Sleep.

PubMed

Hege, Adam; Perko, Michael; Johnson, Amber; Yu, Chong Ho; Sönmez, Sevil; Apostolopoulos, Yorghos

2015-06-01

Given the long hours on the road involving multiple and interacting work stressors (i.e., delivery pressures, irregular shifts, ergonomic hazards), commercial drivers face a plethora of health and safety risks. Researchers goal was to determine whether and to what extent long-haul trucker work schedules influence sleep duration and quality. Survey and biometric data collected from male long-haul truck drivers at a major truckstop in central North Carolina over a six month period. Daily hours worked (mean = 11 hours, 55 minutes) and frequency of working over government-mandated daily HOS regulations (23.8% "frequently or always") were statistically significant predictors of sleep duration. Miles driven per week (mean = 2,812.61), irregular daily hours worked (63.8%), and frequency of working over the daily hour limit (23.8% "frequently or always") were statistically significant predictors of sleep quality. Implications of findings suggest a comprehensive review of the regulations and operational conditions for commercial motor vehicle drivers be undertaken.

The relationship of chronobiology to sleep schedules and performance demands

NASA Technical Reports Server (NTRS)

Monk, T. H.

1990-01-01

This review is concerned with how chronobiological results concerning the human circadian timekeeping system ( biological clock'), its response to changes in schedule, and its influence on performance ability can be used to improve shift worker wellbeing, safety and productivity.

Metabolic consequences of sleep and circadian disorders

PubMed Central

Depner, Christopher M.; Stothard, Ellen R.; Wright, Kenneth P.

2014-01-01

Sleep and circadian rhythms modulate or control daily physiological patterns with importance for normal metabolic health. Sleep deficiencies associated with insufficient sleep schedules, insomnia with short-sleep duration, sleep apnea, narcolepsy, circadian misalignment, shift work, night eating syndrome and sleep-related eating disorder may all contribute to metabolic dysregulation. Sleep deficiencies and circadian disruption associated with metabolic dysregulation may contribute to weight gain, obesity, and type 2 diabetes potentially by altering timing and amount of food intake, disrupting energy balance, inflammation, impairing glucose tolerance and insulin sensitivity. Given the rapidly increasing prevalence of metabolic diseases, it is important to recognize the role of sleep and circadian disruption in the development, progression, and morbidity of metabolic disease. Some findings indicate sleep treatments and countermeasures improve metabolic health, but future clinical research investigating prevention and treatment of chronic metabolic disorders through treatment of sleep and circadian disruption is needed. PMID:24816752

The Association Between Anxiety Symptoms and Sleep in School-Aged Children: A Combined Insight From the Children's Sleep Habits Questionnaire and Actigraphy.

PubMed

Fletcher, Fay E; Conduit, Russell; Foster-Owens, Mistral D; Rinehart, Nicole J; Rajaratnam, Shantha M W; Cornish, Kim M

2018-01-01

The current study assessed the association between anxiety symptoms and sleep in 90 school-aged children, aged 6-12 years (M age = 108 months, 52.2% male). The Children's Sleep Habits Questionnaire (CSHQ) and 14 nights of actigraphy were used to assess sleep. Anxiety was assessed using the Spence Children's Anxiety Scale (SCAS). A significant association was found between parent-reported anxiety symptoms and current sleep problems (i.e., CSHQ total scores ≥ 41). An examination of SCAS subscales identified a specific association between generalized anxiety disorder (GAD) symptoms and increased parental sleep concerns, including sleep onset delay, sleep duration, and daytime sleepiness. Regarding actigraphy, whilst anxiety was not associated with average sleep variables, a relationship was identified between anxiety and the night-to-night variability of actigraphy-derived sleep schedules.

Metabolic consequences of sleep and circadian disorders.

PubMed

Depner, Christopher M; Stothard, Ellen R; Wright, Kenneth P

2014-07-01

Sleep and circadian rhythms modulate or control daily physiological patterns with importance for normal metabolic health. Sleep deficiencies associated with insufficient sleep schedules, insomnia with short-sleep duration, sleep apnea, narcolepsy, circadian misalignment, shift work, night eating syndrome, and sleep-related eating disorder may all contribute to metabolic dysregulation. Sleep deficiencies and circadian disruption associated with metabolic dysregulation may contribute to weight gain, obesity, and type 2 diabetes potentially by altering timing and amount of food intake, disrupting energy balance, inflammation, impairing glucose tolerance, and insulin sensitivity. Given the rapidly increasing prevalence of metabolic diseases, it is important to recognize the role of sleep and circadian disruption in the development, progression, and morbidity of metabolic disease. Some findings indicate sleep treatments and countermeasures improve metabolic health, but future clinical research investigating prevention and treatment of chronic metabolic disorders through treatment of sleep and circadian disruption is needed.

A randomized trial of a three-hour protected nap period in a medicine training program: sleep, alertness, and patient outcomes.

PubMed

Shea, Judy A; Dinges, David F; Small, Dylan S; Basner, Mathias; Zhu, Jingsan; Norton, Laurie; Ecker, Adrian J; Novak, Cristina; Bellini, Lisa M; Dine, C Jessica; Mollicone, Daniel J; Volpp, Kevin G

2014-03-01

Protected sleep periods for internal medicine interns have previously resulted in increased amount slept and improved cognitive alertness but required supplemental personnel. The authors evaluated intern and patient outcomes associated with protected nocturnal nap periods of three hours that are personnel neutral. Randomized trial at Philadelphia Veterans Affairs Medical Center (PVAMC) Medical Service and Hospital of the University of Pennsylvania (HUP) Oncology Unit. During 2010-2011, four-week blocks were randomly assigned to a standard intern schedule (extended duty overnight shifts of up to 30 hours), or sequential protected sleep periods (phone sign-out midnight to 3:00 AM [early shift] intern 1; 3:00 to 6:00 AM [late shift] intern 2). Participants wore wrist Actiwatches, completed sleep diaries, and performed daily assessments of behavioral alertness. Between-group comparisons of means and proportions controlled for within-person correlations. HUP interns had significantly longer sleep durations during both early (2.40 hours) and late (2.44 hours) protected periods compared with controls (1.55 hours, P < .0001). At PVAMC sleep duration was longer only for the late shift group (2.40 versus 1.90 hours, P < .036). Interns assigned to either protected period were significantly less likely to have call nights with no sleep and had fewer attentional lapses on the Psychomotor Vigilance Test. Differences in patient outcomes between standard schedule months versus intervention months were not observed. Protected sleep periods of three hours resulted in more sleep during call and reductions in periods of prolonged wakefulness, providing a plausible alternative to 16-hour shifts.

Extreme late chronotypes and social jetlag challenged by Antarctic conditions in a population of university students from Uruguay.

PubMed

Tassino, Bettina; Horta, Stefany; Santana, Noelia; Levandovski, Rosa; Silva, Ana

2016-01-01

In humans, a person's chronotype depends on environmental cues and on individual characteristics, with late chronotypes prevailing in youth. Social jetlag (SJL), the misalignment between an individual׳s biological clock and social time, is higher in late chronotypes. Strong SJL is expected in Uruguayan university students with morning class schedules and very late entertainment activities. Sleep disorders have been reported in Antarctic inhabitants, that might be a response to the extreme environment or to the strictness of Antarctic life. We evaluated, for the first time in Uruguay, the chronotypes and SJL of 17 undergraduate students of the First Uruguayan Summer School on Antarctic Research, using Munich Chronotype Questionnaire (MCTQ) and sleep logs (SL) recorded during 3 phases: pre-Antarctic, Antarctic, and post-Antarctic. The midsleep point of free days corrected for sleep debt on work days (MSFsc,) was used as proxy of individuals' chronotype, whose values (around 6 a.m.) are the latest ever reported. We found a SJL of around 2 h in average, which correlated positively with MSFsc, confirming that late chronotypes generate a higher sleep debt during weekdays. Midsleep point and sleep duration significantly decreased between pre-Antarctic and Antarctic phases, and sleep duration rebounded to significant higher values in the post-Antarctic phase. Waking time, but not sleep onset time, significantly varied among phases. This evidence suggests that sleep schedules more likely depended on the social agenda than on the environmental light-dark shifts. High motivation of students towards Antarctic activities likely induced a subjective perception of welfare non-dependent on sleep duration.

Circadian Adaptation to Night Shift Work Influences Sleep, Performance, Mood and the Autonomic Modulation of the Heart

PubMed Central

Boudreau, Philippe; Dumont, Guy A.; Boivin, Diane B.

2013-01-01

Our aim was to investigate how circadian adaptation to night shift work affects psychomotor performance, sleep, subjective alertness and mood, melatonin levels, and heart rate variability (HRV). Fifteen healthy police officers on patrol working rotating shifts participated to a bright light intervention study with 2 participants studied under two conditions. The participants entered the laboratory for 48 h before and after a series of 7 consecutive night shifts in the field. The nighttime and daytime sleep periods were scheduled during the first and second laboratory visit, respectively. The subjects were considered “adapted” to night shifts if their peak salivary melatonin occurred during their daytime sleep period during the second visit. The sleep duration and quality were comparable between laboratory visits in the adapted group, whereas they were reduced during visit 2 in the non-adapted group. Reaction speed was higher at the end of the waking period during the second laboratory visit in the adapted compared to the non-adapted group. Sleep onset latency (SOL) and subjective mood levels were significantly reduced and the LF∶HF ratio during daytime sleep was significantly increased in the non-adapted group compared to the adapted group. Circadian adaptation to night shift work led to better performance, alertness and mood levels, longer daytime sleep, and lower sympathetic dominance during daytime sleep. These results suggest that the degree of circadian adaptation to night shift work is associated to different health indices. Longitudinal studies are required to investigate long-term clinical implications of circadian misalignment to atypical work schedules. PMID:23923024

Daily Profiles of Light Exposure and Evening Use of Light-emitting Devices in Young Adults Complaining of a Delayed Sleep Schedule.

PubMed

Van der Maren, Solenne; Moderie, Christophe; Duclos, Catherine; Paquet, Jean; Daneault, Véronique; Dumont, Marie

2018-04-01

A number of factors can contribute to a delayed sleep schedule. An important factor could be a daily profile of light exposure favoring a later circadian phase. This study aimed to compare light exposure between 14 young adults complaining of a delayed sleep schedule and 14 matched controls and to identify possible associations between habitual light exposure and circadian phase. Exposure to white and blue light was recorded with ambulatory monitors for 7 consecutive days. Participants also noted their daily use of light-emitting devices before bedtime. Endogenous circadian phase was estimated with the dim light melatonin onset (DLMO) in the laboratory. The amplitude of the light-dark cycle to which the subjects were exposed was smaller in delayed than in control subjects, and smaller amplitude was associated with a later DLMO. Smaller amplitude was due to both decreased exposure in the daytime and increased exposure at night. Total exposure to blue light, but not to white light, was lower in delayed subjects, possibly due to lower exposure to blue-rich outdoor light. Lower daily exposure to blue light was associated with a later DLMO. Timing of relative increases and decreases of light exposure in relation to endogenous circadian phase was also compared between the 2 groups. In delayed subjects, there was a relatively higher exposure to white and blue light 2 h after DLMO, a circadian time with maximal phase-delaying effect. Delayed participants also had higher exposure to light 8 to 10 h after DLMO, which occurred mostly during their sleep episode but may have some phase-advancing effects. Self-reported use of light-emitting devices before bedtime was higher in delayed than in control subjects and was associated with a later DLMO. This study suggests that individuals complaining of a delayed sleep schedule engage in light-related behaviors favoring a later circadian phase and a later bedtime.

Complete or partial circadian re-entrainment improves performance, alertness, and mood during night-shift work.

PubMed

Crowley, Stephanie J; Lee, Clara; Tseng, Christine Y; Fogg, Louis F; Eastman, Charmane I

2004-09-15

To assess performance, alertness, and mood during the night shift and subsequent daytime sleep in relation to the degree of re-alignment (re-entrainment) of circadian rhythms with a night-work, day-sleep schedule. Subjects spent 5 consecutive night shifts (11:00 pm-7:00 am) in the lab and slept at home in darkened bedrooms (8:30 am-3:30 pm). Subjects were categorized by the degree of re-entrainment attained after the 5 night shifts. Completely re-entrained: temperature minimum in the second half of daytime sleep; partially re-entrained: temperature minimum in the first half of daytime sleep; not re-entrained: temperature minimum did not delay enough to reach daytime sleep. See above. Young healthy adults (n = 67) who were not shift workers. Included bright light during the night shifts, sunglasses worn outside, a fixed dark daytime sleep episode, and melatonin. The effects of various combinations of these interventions on circadian re-entrainment were previously reported. Here we report how the degree of re-entrainment affected daytime sleep and measures collected during the night shift. Salivary melatonin was collected every 30 minutes in dim light (<20 lux) before and after the night shifts to determine the dim light melatonin onset, and the temperature minimum was estimated by adding a constant (7 hours) to the dim light melatonin onset. Subjects kept sleep logs, which were verified by actigraphy. The Neurobehavioral Assessment Battery was completed several times during each night shift. Baseline sleep schedules and circadian phase differed among the 3 re-entrainment groups, with later times resulting in more re-entrainment. The Neurobehavioral Assessment Battery showed that performance, sleepiness, and mood were better in the groups that re-entrained compared to the group that did not re-entrain, but there were no significant differences between the partial and complete re-entrainment groups. Subjects slept almost all of the allotted 7 hours during the day, and duration did not significantly differ among the re-entrainment groups. In young people, complete re-entrainment to the night-shift day-sleep schedule is not necessary to produce substantial benefits in neurobehavioral measures; partial re-entrainment (delaying the temperature minimum into the beginning of daytime sleep) is sufficient. The group that did not re-entrain shows that a reasonable amount of daytime sleep is not enough to produce good neurobehavioral performance during the night shift. Therefore, some re-alignment of circadian rhythms is recommended.

Reduction of Sleep Deprivation and Fatigue in Mass Transit Rail Operators.

PubMed

Haynes, Ajeenah L

2017-08-01

Sleep and work schedules differ considerably between rail workers and the broader U.S. workforce. Due to extended work hours and night shift schedules, train and engine service workers who operate passenger trains or move freight are most vulnerable to fatigue. This article addresses the need for comprehensive fatigue risk management systems (FRMS) for rail operators. Using a transactional ergonomic perspective, FRMS are discussed with a focus on fatigue education and administrative controls to reduce feelings of tiredness, low motivation, poor concentration, and low physical activity among mass transit rail operators. Recommendations for intervention implementation and evaluation are provided.

Sleep and respiration in microgravity

NASA Technical Reports Server (NTRS)

Prisk, G. K.

1998-01-01

Sleep studies conducted during the STS-90 Neurolab mission are explored. The relationship between sleep, melatonin, and circadian phase is reviewed. The study contained both sleep and awake components. The objectives of the sleep component were to test five hypotheses: that circadian rhythms of core body temperature and urinary melatonin are synchronized to required sleep-wake schedules, that spaceflight results in substantial disruption of sleep, that the pattern of chest and abdominal wall motion alters during the different sleep stages in microgravity, that arterial oxygen saturation is reduced during some stages of sleep in microgravity, and that pre-sleep administration of melatonin during microgravity results in improved sleep quality. The awake component tested three hypotheses: that ventilatory response to carbon dioxide is increased during exposure to microgravity and that this exacerbates sleep disruption, that ventilatory response to hypoxia is increased by exposure to microgravity, and that the improved sleep resulting from the pre-sleep administration of melatonin enhances next day cognition when compared to placebo.

The relationship between sleep habits and academic performance in dental students in Croatia.

PubMed

Valic, M; Pecotic, R; Lusic, L; Peros, K; Pribudic, Z; Dogas, Z

2014-11-01

It is well accepted that sleep and lifestyle habits affect academic success in students. However, sleep patterns and sleep problems amongst dental students have been insufficiently addressed in the literature. The purpose of this study was to evaluate sleep habits of dental students and the relationship between sleep habits and academic performance. A self-administered questionnaire on sleep habits, academic performance and lifestyle was administered. The participants were 447 dental students from Split University Dental Medicine School and Zagreb University Dental Medicine School from the six academic years. The subjects were classified into two groups based on academic success (high-performing vs. low-performing students) for comparison of sleep and lifestyle habits. Amongst the whole group of students, average bedtime and wake time during weekday was significantly earlier compared with weekend. Main findings indicate that students with high academic performance had earlier bedtimes during weekdays and weekends, earlier wake times during weekends and shorter sleep latency compared with low academic performing students. Self-reported academic performance of dental students in Croatia is associated with timing of sleep and wakefulness, rather than with total sleep time duration. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sleep restriction may lead to disruption in physiological attention and reaction time.

PubMed

Choudhary, Arbind Kumar; Kishanrao, Sadawarte Sahebrao; Dadarao Dhanvijay, Anup Kumar; Alam, Tanwir

2016-01-01

Sleepiness is the condition where for some reason fails to go into a sleep state and will have difficulty in remaining awake even while carrying out activities. Sleep restriction occurs when an individual fails to get enough sleep due to high work demands. The mechanism between sleep restriction and underlying brain physiology deficits is not well assumed. The objective of the present study was to investigate the mental attention (P300) and reaction time [visual (VRT) and auditory (ART)] among night watchmen, at subsequent; first (1st) day, fourth (4th) day and seventh (7th) day of restricted sleep period. After exclusion and inclusion criteria, the study was performed among 50 watchmen (age=18-35 years) (n=50) after providing written informed consent and divided into two group. Group I-(Normal sleep) (n=28) working in day time and used to have normal sleep in night (≥8 h); Group II-(Restricted sleep) (n=22) - working in night time and used to have less sleep in night (≤3 h). Statistical significance between the different groups was determined by the independent student ' t ' test and the significance level was fixed at p≤0.05. We observed that among all normal and restricted sleep watchmen there was not any significant variation in Karolinska Sleepiness Scale (KSS) score, VRT and ART, along with latency and amplitude of P300 on 1st day of restricted sleep. However at subsequent on 4th day and 7th day of restricted sleep, there was significant increase in (KSS)score, and prolongation of VRT and ART as well as alteration in latency and amplitude of P300 wave in restricted sleep watchmen when compare to normal sleep watchmen. The present finding concludes that loss of sleep has major impact in dynamic change in mental attention and reaction time among watchmen employed in night shift. Professional regulations and work schedules should integrate sleep schedules before and during the work period as an essential dimension for their healthy life.

Sleeping under the Ocean: Despite Total Isolation, Nuclear Submariners Maintain Their Sleep and Wake Patterns throughout Their Under Sea Mission

PubMed Central

Trousselard, Marion; Leger, Damien; van Beers, Pascal; Coste, Olivier; Vicard, Arnaud; Pontis, Julien; Crosnier, Sylvain-Nicolas; Chennaoui, Mounir

2015-01-01

Background To assess the effects of isolation, inadequate exposure to light and specific shift work on the subjective and objective measurements of sleep and alertness of submariners. Purpose A strictly controlled randomized crossover study with the polysomnography recorded twice during the mission. Methods Setting: Shift and night work with prolonged (70 days) social isolation from the real world (with no phone or Internet contact with families or friends during a routine mission aboard the “Téméraire” French Strategic Submarine with Ballistic Nuclear missiles (SSBN). Participants: 19 submariners working on a 24-hour shift for three days in a row schedule. Interventions: The participants attended two polysomnographic (PSG) recordings of night sleep on Day 21 (D21) and Day 51 (D51) of the 70-day patrol; urine cortisol levels were also taken after sleep, and subjective assessments of sleep, sleepiness, mood and anxiety on D21 and D51. The light and temperature on board were also recorded. Results PSG analyses showed that sleep did not significantly vary in length (total sleep time) or in quality between D21 and D51. The mariners reported the same subjective sleep, sleepiness, anxiety or mood (except for a slightly worse score for confusion on D51). Blood cortisol levels did not vary significantly. Conclusions These results show that humans living in an isolated environment for more than two months with this specific shift schedule do not suffer from any significant effects on sleep, sleepiness and confusion between D21 and D51, when they follow an organized regular shift pattern with controlled light and temperature. PMID:26016656

Behavioral sleep modification may revert transformed migraine to episodic migraine.

PubMed

Calhoun, Anne H; Ford, Sutapa

2007-09-01

Sleep problems have been linked with headaches for more than a century, but whether the headaches are the cause or the result of the disrupted sleep is unknown. We previously reported that nonrestorative sleep and poor sleep habits are almost universal in a referral population of women with transformed migraine (TM). Since cognitive behavioral therapy is effective in improving sleep quality in individuals with poor sleep hygiene, we designed a randomized, placebo-controlled study to assess the impact of such treatment on TM. We hypothesized that behavioral sleep modification (BSM) would be associated with improvement in headache frequency and intensity and with reversion to episodic migraine. Subjects were 43 women with TM referred to an academic headache center. After obtaining informed consent, patients were randomized to receive either behavioral sleep instructions or placebo behavioral instructions in addition to usual medical care. Subjects recorded headaches in standardized diaries. The first postintervention visit was scheduled at 6 weeks. At that visit, the blind was broken and all subjects received BSM instructions. A final visit was scheduled 6 weeks later. Compared to the placebo behavioral group, the BSM group reported statistically significant reduction in headache frequency [F (1, 33 = 12.42, P=.001)] and headache intensity [F(1, 33 = 14.39, P= .01)]. They were more likely to revert to episodic migraine chi2 (2, n = 43) = 7.06, P= .029. No member of the control group reverted to episodic migraine by the first postintervention visit. By the final visit, 48.5% of those who had received BSM instructions had reverted to episodic migraine. In this pilot study of women with TM, we found that a targeted behavioral sleep invention was associated with improvement in headache frequency, headache index, and with reversion to episodic migraine.

Circadian variation of EEG power spectra in NREM and REM sleep in humans: dissociation from body temperature

NASA Technical Reports Server (NTRS)

Dijk, D. J.

1999-01-01

In humans, EEG power spectra in REM and NREM sleep, as well as characteristics of sleep spindles such as their duration, amplitude, frequency and incidence, vary with circadian phase. Recently it has been hypothesized that circadian variations in EEG spectra in humans are caused by variations in brain or body temperature and may not represent phenomena relevant to sleep regulatory processes. To test this directly, a further analysis of EEG power spectra - collected in a forced desynchrony protocol in which sleep episodes were scheduled to a 28-h period while the rhythms of body temperature and plasma melatonin were oscillating at their near 24-h period - was carried out. EEG power spectra were computed for NREM and REM sleep occurring between 90-120 and 270-300 degrees of the circadian melatonin rhythm, i.e. just after the clearance of melatonin from plasma in the 'morning' and just after the 'evening' increase in melatonin secretion. Average body temperatures during scheduled sleep at these two circadian phases were identical (36.72 degrees C). Despite identical body temperatures, the power spectra in NREM sleep were very different at these two circadian phases. EEG activity in the low frequency spindle range was significantly and markedly enhanced after the evening increase in plasma melatonin as compared to the morning phase. For REM sleep, significant differences in power spectra during these two circadian phases, in particular in the alpha range, were also observed. The results confirm that EEG power spectra in NREM and REM sleep vary with circadian phase, suggesting that the direct contribution of temperature to the circadian variation in EEG power spectra is absent or only minor, and are at variance with the hypothesis that circadian variations in EEG power spectra are caused by variations in temperature.

Understanding adolescents' sleep patterns and school performance: a critical appraisal.

PubMed

Wolfson, Amy R; Carskadon, Mary A

2003-12-01

The present paper reviews and critiques studies assessing the relation between sleep patterns, sleep quality, and school performance of adolescents attending middle school, high school, and/or college. The majority of studies relied on self-report, yet the researchers approached the question with different designs and measures. Specifically, studies looked at (1) sleep/wake patterns and usual grades, (2) school start time and phase preference in relation to sleep habits and quality and academic performance, and (3) sleep patterns and classroom performance (e.g., examination grades). The findings strongly indicate that self-reported shortened total sleep time, erratic sleep/wake schedules, late bed and rise times, and poor sleep quality are negatively associated with academic performance for adolescents from middle school through the college years. Limitations of the current published studies are also discussed in detail in this review.

Solving the mystery of human sleep schedules one mutation at a time.

PubMed

Hallows, William C; Ptáček, Louis J; Fu, Ying-Hui

2013-01-01

Sleep behavior remains one of the most enigmatic areas of life. The unanswered questions range from "why do we sleep?" to "how we can improve sleep in today's society?" Identification of mutations responsible for altered circadian regulation of human sleep lead to unique opportunities for probing these territories. In this review, we summarize causative circadian mutations found from familial genetic studies to date. We also describe how these mutations mechanistically affect circadian function and lead to altered sleep behaviors, including shifted or shortening of sleep patterns. In addition, we discuss how the investigation of mutations can not only expand our understanding of the molecular mechanisms regulating the circadian clock and sleep duration, but also bridge the pathways between clock/sleep and other human physiological conditions and ailments such as metabolic regulation and migraine headaches.

Randomized placebo-controlled field study of the effects of bright light and melatonin in adaptation to night work.

PubMed

Bjorvatn, Bjørn; Stangenes, Kristine; Oyane, Nicolas; Forberg, Knut; Lowden, Arne; Holsten, Fred; Akerstedt, Torbjørn

2007-06-01

This study evaluated the effects of bright light and melatonin on adaptation to night work on an oil rig in the North Sea. Seventeen persons working a schedule of 2 weeks on a 12-hour shift, with the first week on night shift and the second week on day shift (ie, the swing shift schedule) participated. In a randomized controlled crossover design, the shift workers received a placebo, melatonin (3 mg, 1 hour before bedtime), or bright light (30-minute exposure, individually scheduled) during the first 4 days on the night shift and during the first 4 days on the day shift. Subjective and objective measures of sleepiness (Karolinska Sleepiness Scale and a simple serial reaction-time test) and sleep (diary and actigraphy) were recorded. Subjective measures indicated that melatonin modestly reduced sleepiness at work during the day shift and increased sleep by 15-20 minutes per day. Bright light gave values in between those of melatonin and the placebo, but with few significant results. According to the objective measures, bright light improved sleep to a minor degree during the night shift. Hardly any side-effects were reported. Melatonin and bright light modestly improved sleep and sleepiness in this field study. In well-controlled simulated nightwork studies, both melatonin and bright light are more effective in alleviating sleepiness and sleep problems. The less effect in this field study may be due to competing or conflicting factors present in real life or to an inoptimal timing and duration of the treatments.

Cosleeping and Behavioral Sleep Problems in School-aged Children with Neurodevelopmental and Mental Health Disorders.

PubMed

Bastida-Pozuelo, María-Felisa; Meltzer, Lisa J; Sánchez-Ortuño, María-Montserrat

2018-06-01

The aim of this study was to explore the presence of sleep-related complaints and their relationship to cosleeping in a sample of 57 children with mental health disorders. Information about the practice of cosleeping was collected through an interview and behavioral sleep problems were evaluated with a subset of items from the Spanish version of the Pediatric Sleep Questionnaire (PSQ). Controlling for age, cosleepers scored higher on insomnia, daytime sleepiness and poor sleep scheduling, compared to solitary sleepers. Therefore, mental health professionals should explore the child's sleep environment and, when necessary, use appropriate interventions to address such problems. Copyright © 2018 Elsevier Inc. All rights reserved.

The Efficacy of a Restart Break for Recycling with Optimal Performance Depends Critically on Circadian Timing

PubMed Central

Van Dongen, Hans P.A.; Belenky, Gregory; Vila, Bryan J.

2011-01-01

Objectives: Under simulated shift-work conditions, we investigated the efficacy of a restart break for maintaining neurobehavioral functioning across consecutive duty cycles, as a function of the circadian timing of the duty periods. Design: As part of a 14-day experiment, subjects underwent two cycles of five simulated daytime or nighttime duty days, separated by a 34-hour restart break. Cognitive functioning and high-fidelity driving simulator performance were tested 4 times per day during the two duty cycles. Lapses on a psychomotor vigilance test (PVT) served as the primary outcome variable. Selected sleep periods were recorded polysomnographically. Setting: The experiment was conducted under standardized, controlled laboratory conditions with continuous monitoring. Participants: Twenty-seven healthy adults (13 men, 14 women; aged 22–39 years) participated in the study. Interventions: Subjects were randomly assigned to a nighttime duty (experimental) condition or a daytime duty (control) condition. The efficacy of the 34-hour restart break for maintaining neurobehavioral functioning from the pre-restart duty cycle to the post-restart duty cycle was compared between these two conditions. Results: Relative to the daytime duty condition, the nighttime duty condition was associated with reduced amounts of sleep, whereas sleep latencies were shortened and slow-wave sleep appeared to be conserved. Neurobehavioral performance measures ranging from lapses of attention on the PVT to calculated fuel consumption on the driving simulators remained optimal across time of day in the daytime duty schedule, but degraded across time of night in the nighttime duty schedule. The 34-hour restart break was efficacious for maintaining PVT performance and other objective neurobehavioral functioning profiles from one duty cycle to the next in the daytime duty condition, but not in the nighttime duty condition. Subjective sleepiness did not reliably track objective neurobehavioral deficits. Conclusions: The 34-hour restart break was adequate for maintaining performance in the case of optimal circadian placement of sleep and duty periods (control condition) but was inadequate (and perhaps even detrimental) for maintaining performance in a simulated nighttime duty schedule (experimental condition). Current US transportation hours-of-service regulations mandate time off duty but do not consider the circadian aspects of shift scheduling. Reinforcing a recent trend of applying sleep science to inform policymaking for duty and rest times, our findings indicate that restart provisions in hours-of-service regulations could be improved by taking the circadian timing of the duty schedules into account. Citation: Van Dongen HPA; Belenky G; Vila BJ. The efficacy of a restart break for recycling with optimal performance depends critically on circadian timing. SLEEP 2011;34(7):917-929. PMID:21731142

Factors affecting work ability in day and shift-working nurses.

PubMed

Camerino, Donatella; Conway, Paul Maurice; Sartori, Samantha; Campanini, Paolo; Estryn-Béhar, Madeleine; van der Heijden, Beatrice Isabella Johanna Maria; Costa, Giovanni

2008-04-01

Satisfactory work ability is sustained and promoted by good physical and mental health and by favorable working conditions. This study examined whether favorable and rewarding work-related factors increased the work ability among European nurses. The study sample was drawn from the Nurses' Early Exit Study and consisted of 7,516 nursing staff from seven European countries working in state-owned and private hospitals. In all, 10.8% were day, 4.2% were permanent night, 20.9% were shift without night shift, and 64.1% were shift workers with night shifts. Participants were administered a composite questionnaire at baseline (Time 0) and 1 yr later (Time 1). The Work Ability Index (WAI) at Time 1 was used as the outcome measure, while work schedule, sleep, rewards (esteem and career), satisfaction with pay, work involvement and motivation, and satisfaction with working hours at Time 0 were included as potential determinants of work ability. Univariate and multivariate analyses were conducted after adjusting for a number of confounders (i.e., country, age, sex, type of employment, family status, and other job opportunities in the same area). Work schedule was not related to Time 1 changes in WAI. Higher sleep quality and quantity and more favorable psychosocial factors significantly increased work ability levels. Higher sleep quality and quantity did not mediate the effect of work schedule on work ability. No relevant interaction effects on work ability were observed between work schedule and the other factors considered at Time 0. As a whole, sleep and satisfaction with working time were gradually reduced from day work to permanent night work. However, scores on work involvement, motivation, and satisfaction with pay and rewards were the highest in permanent night workers and the lowest in rotating shift workers that included night shifts.

Sleep patterns, work, and strain among young students in hospitality and tourism.

PubMed

Brand, Serge; Hermann, Bernadette; Muheim, Flavio; Beck, Johannes; Holsboer-Trachsler, Edith

2008-07-01

Good and sufficient sleep is crucial for a good quality of life. We investigated the associations between sleep patterns, work, and strain among students of hospitality and tourism. 92 students completed psychological and sleep-related questionnaires, and a sleep/work log for one week. Sleeping hours were inversely correlated with working hours. Decreased sleep quality was associated with increased scores of strain, depression and anxiety. Participants with increased working hours were 3.2 times more likely to report heightened insomnia scores than those with lower weekly working hours. Working on weekends was associated with increased strain with family life and peers. In hospitality and tourism, the employees' 'personal costs' for a 24/7 service may be underestimated; unfavourable work schedules are linked with decreased sleep quality, symptoms of depression, anxiety, and with social problems.

Sleep loss and circadian disruption in shift work: health burden and management.

PubMed

Rajaratnam, Shantha M W; Howard, Mark E; Grunstein, Ronald R

2013-10-21

About 1.5 million Australians are shift workers. Shift work is associated with adverse health, safety and performance outcomes. Circadian rhythm misalignment, inadequate and poor-quality sleep, and sleep disorders such as sleep apnoea, insomnia and shift work disorder (excessive sleepiness and/or insomnia temporally associated with the work schedule) contribute to these associations. Falling asleep at work at least once a week occurs in 32%-36% of shift workers. Risk of occupational accidents is at least 60% higher for non-day shift workers. Shift workers also have higher rates of cardiometabolic diseases and mood disturbances. Road and workplace accidents related to excessive sleepiness, to which shift work is a significant contributor, are estimated to cost $71-$93 billion per annum in the United States. There is growing evidence that understanding the interindividual variability in sleep-wake responses to shift work will help detect and manage workers vulnerable to the health consequences of shift work. A range of approaches can be used to enhance alertness in shift workers, including screening and treating sleep disorders, melatonin treatment to promote sleep during the daytime, and avoidance of inappropriate use of sedatives and wakefulness-promoters such as modafinil and caffeine. Short naps, which minimise sleep inertia, are generally effective. Shifting the circadian pacemaker with appropriately timed melatonin and/or bright light may be used to facilitate adjustment to a shift work schedule in some situations, such as a long sequence of night work. It is important to manage the health risk of shift workers by minimising vascular risk factors through dietary and other lifestyle approaches.

Extreme late chronotypes and social jetlag challenged by Antarctic conditions in a population of university students from Uruguay

PubMed Central

Tassino, Bettina; Horta, Stefany; Santana, Noelia; Levandovski, Rosa; Silva, Ana

2016-01-01

In humans, a person’s chronotype depends on environmental cues and on individual characteristics, with late chronotypes prevailing in youth. Social jetlag (SJL), the misalignment between an individual׳s biological clock and social time, is higher in late chronotypes. Strong SJL is expected in Uruguayan university students with morning class schedules and very late entertainment activities. Sleep disorders have been reported in Antarctic inhabitants, that might be a response to the extreme environment or to the strictness of Antarctic life. We evaluated, for the first time in Uruguay, the chronotypes and SJL of 17 undergraduate students of the First Uruguayan Summer School on Antarctic Research, using Munich Chronotype Questionnaire (MCTQ) and sleep logs (SL) recorded during 3 phases: pre-Antarctic, Antarctic, and post-Antarctic. The midsleep point of free days corrected for sleep debt on work days (MSFsc,) was used as proxy of individuals’ chronotype, whose values (around 6 a.m.) are the latest ever reported. We found a SJL of around 2 h in average, which correlated positively with MSFsc, confirming that late chronotypes generate a higher sleep debt during weekdays. Midsleep point and sleep duration significantly decreased between pre-Antarctic and Antarctic phases, and sleep duration rebounded to significant higher values in the post-Antarctic phase. Waking time, but not sleep onset time, significantly varied among phases. This evidence suggests that sleep schedules more likely depended on the social agenda than on the environmental light–dark shifts. High motivation of students towards Antarctic activities likely induced a subjective perception of welfare non-dependent on sleep duration. PMID:27226819

Fatigue in U.S. Astronauts Onboard the International Space Station: Environmental Factors, Operational Impacts, and Implementation of Countermeasures

NASA Technical Reports Server (NTRS)

Scheuring, R. A.; Moomaw, R. C.; Johnston, S. L.

2014-01-01

Since 2000, US astronauts have been supporting missions up to a six month duration on the International Space Station (ISS). Crewmembers have experienced fatigue for reasons similar to military deployments. Astronauts experience psychological stressors such as heavy workloads, extended duty periods, circadian misalignment, inadequate/ineffective sleep, and loss of the environmental cues of a gravity environment. Complicating the psychological stressors are environmental factors; distracting background noise, unexpected and variable mission schedules, unfavorable thermal control, elevated CO2 levels, and an unusual sleep environment with schedules that impinge on pre-sleep periods. Physiological contributors to poor sleep and fatigue include a cephalad fluid shift and back pain. Restful sleep is further challenged due to a lack of gravity-related proprioceptive cues and need for restraints. The term "space fog" has been used by astronauts to describe a phenomenon of forgetfulness, slowed reaction time and transient confusion while trying to complete tasks. There is a distinct temporal correlation with arrival on the Space Station and the onset of slowed cognitive skills and a spontaneous resolution that may take up to 6 weeks. The Genesis of this phenomenon may be chronic fatigue secondary to transitioning from a planar environment to a 360deg microgravity perspective. Recently, countermeasures to improve sleep duration and quality in astronauts on the ISS have been instituted with moderate degrees of success as measured by self-reaction time (psychomotor vigilance task testing), actigraphy, and subjective reports. Judicious use of stimulants and hypnotics, light therapy, controlled sleep periods and sleep shifting and reducing ambient CO2 levels are a few of the most promising countermeasures being used in space to improve sleep and reduce fatigue.

Sleep quality in long haul truck drivers: A study on Iranian national data.

PubMed

Sadeghniiat-Haghighi, Khosro; Yazdi, Zohreh; Kazemifar, Amir-Mohammad

2016-08-01

Iran has a high rate of road traffic accidents. Poor quality of sleep brings about loss of attention, which is an important cause of road traffic accidents particularly in monotonous roads. The causes of poor quality of sleep in occupational drivers are multifactorial. The objective of the present study was to assess the prevalence of poor sleep quality among occupational drivers with rotating work schedules and analyze its different risk factors. 2200 professional long-haul truck drivers who had been referred to the Occupational Health Clinic for routine education course were invited. We obtained data from eight provinces from various parts of Iran during 2012-2013. Data were collected using a questionnaire including questions about demographic and job characteristics. Pittsburg Sleep Quality Index (PSQI) was used to assess drivers' sleep quality. Mean working (driving) time was (9.3±2.5) hours daily and (55.5 ± 18.29) hours weekly. About 23.5% of the drivers reported history of smoking, 14.5% had low job satisfaction and 60% had irregular work schedule. 16.4% of drivers had an accidents leading to injury during the past five years. The mean PSQI score was 4.2 ± 2.7; 54% had a PSQI>5 (poor quality of sleep). Multivariate logistic regression showed that smoking, job satisfaction, history of accidents, shift work and work hours per day were the most important risk factors for poor sleep quality. Results obtained from the current study showed a high prevalence of poor quality of sleep among professional drivers. It warrants more attention to this significant problem using some measures to improve working conditions in professional drivers, as well as health promotion interventions.

Sleep and circadian phase in a ship's crew.

PubMed

Arendt, Josephine; Middleton, Benita; Williams, Peter; Francis, Gavin; Luke, Claire

2006-06-01

Numerous factors influence the increased health risks of seamen. This study investigated sleep (by actigraphy) and the adaptation of the internal clock in watch-keeping crew compared to day workers, as possible contributory factors. Fourteen watch keepers, 4 h on, 8 h off (0800-1200/2000-2400 h, 1200-1600/2400-0400 h, 1600-2000/0400-0800 h) (fixed schedule, n = 6; rotating by delay weekly, n = 8), and 12 day workers participated during a voyage from the United Kingdom to Antarctica. They kept daily sleep diaries and wore wrist monitors for continuous recording of activity. Sleep parameters were derived from activity using the manufacturer's software and analyzed by repeated-measures ANOVA using SAS 8.2. Sequential urine samples were collected for 48 h weekly for 6-sulphatoxymelatonin measurement as an index of circadian rhythm timing. Individuals working watches of 1200-1600/2400-0400 h and 1600-2000/0400-0800 h had 2 sleeps daily, analyzed separately as main sleep (longest) and 2nd sleep. Main sleep duration was shorter in watch keepers than in day workers (p < 0.0001). Objective sleep quality was significantly compromised in rotaters compared to both day workers and fixed watch keepers, the most striking comparisons being sleep efficiency (percentage desired sleep time spent sleeping) main sleep (p < 0.0001) and sleep fragmentation (an index of restlessness) main sleep (p < 0.0001). The 2nd sleep was substantially less efficient than was the main sleep (p < 0.0001) for all watch keepers. There were few significant differences in sleep between the different watches in rotating watch keepers. Circadian timing remained constant in day workers. Timing of the 6-sulphatoxymelatonin rhythm was later for the watch of 1200-1600/2400-0400 h than for all others (1200-1600/2400-0400 h, 5.90 +/- 0.85 h; 1600-2000/0400-0800 h, 1.5 +/- 0.64 h; 0800-1200/ 2000-2400 h, 2.72 +/- 0.76 h; days, 2.09 +/- 0.68 h [decimal hours, mean +/- SEM]: ANOVA, p < 0.01). This study identifies weekly changes in watch time as a cause of poor sleep in watch keepers. The most likely mechanism is the inability of the internal clock to adapt rapidly to abrupt changes in schedule.

Effects of Sleep Deprivation on U.S. Navy Surface Ship Watchstander Performance using Alternative Watch Schedules

DTIC Science & Technology

2012-09-01

75  xi LIST OF TABLES Table 1.  Allocation of Hours per Sailor per Week Based on the Navy Standard Workweek ...sleep than allotted by the Navy Standard Workweek (NSWW). On average, personnel onboard cruisers achieve two- hours less sleep per week and personnel on...fact that the Navy adopted the 168- hour Navy Standard Workweek (NSWW), multiple studies have shown the amount of work conducted by personnel onboard

Case Study: Psychiatric Misdiagnosis of Non-24-Hours Sleep-Wake Schedule Disorder Resolved by Melatonin

ERIC Educational Resources Information Center

Dagan, Yaron; Ayalon, Liat

2005-01-01

This case study describes a 14-year-old male suffering from significant academic and personal difficulties, who has been diagnosed with depression, schizotypal personality disorder, and learning disabilities. Because of excessive sleepiness, assessment for a potential sleep disorder was performed. An overnight polysomnographic study revealed no…

Dim light at night disturbs the daily sleep-wake cycle in the rat.

PubMed

Stenvers, Dirk Jan; van Dorp, Rick; Foppen, Ewout; Mendoza, Jorge; Opperhuizen, Anne-Loes; Fliers, Eric; Bisschop, Peter H; Meijer, Johanna H; Kalsbeek, Andries; Deboer, Tom

2016-10-20

Exposure to light at night (LAN) is associated with insomnia in humans. Light provides the main input to the master clock in the hypothalamic suprachiasmatic nucleus (SCN) that coordinates the sleep-wake cycle. We aimed to develop a rodent model for the effects of LAN on sleep. Therefore, we exposed male Wistar rats to either a 12 h light (150-200lux):12 h dark (LD) schedule or a 12 h light (150-200 lux):12 h dim white light (5 lux) (LDim) schedule. LDim acutely decreased the amplitude of daily rhythms of REM and NREM sleep, with a further decrease over the following days. LDim diminished the rhythms of 1) the circadian 16-19 Hz frequency domain within the NREM sleep EEG, and 2) SCN clock gene expression. LDim also induced internal desynchronization in locomotor activity by introducing a free running rhythm with a period of ~25 h next to the entrained 24 h rhythm. LDim did not affect body weight or glucose tolerance. In conclusion, we introduce the first rodent model for disturbed circadian control of sleep due to LAN. We show that internal desynchronization is possible in a 24 h L:D cycle which suggests that a similar desynchronization may explain the association between LAN and human insomnia.

Dim light at night disturbs the daily sleep-wake cycle in the rat

PubMed Central

Jan Stenvers, Dirk; van Dorp, Rick; Foppen, Ewout; Mendoza, Jorge; Opperhuizen, Anne-Loes; Fliers, Eric; Bisschop, Peter H.; Meijer, Johanna H.; Kalsbeek, Andries; Deboer, Tom

2016-01-01

Exposure to light at night (LAN) is associated with insomnia in humans. Light provides the main input to the master clock in the hypothalamic suprachiasmatic nucleus (SCN) that coordinates the sleep-wake cycle. We aimed to develop a rodent model for the effects of LAN on sleep. Therefore, we exposed male Wistar rats to either a 12 h light (150–200lux):12 h dark (LD) schedule or a 12 h light (150–200 lux):12 h dim white light (5 lux) (LDim) schedule. LDim acutely decreased the amplitude of daily rhythms of REM and NREM sleep, with a further decrease over the following days. LDim diminished the rhythms of 1) the circadian 16–19 Hz frequency domain within the NREM sleep EEG, and 2) SCN clock gene expression. LDim also induced internal desynchronization in locomotor activity by introducing a free running rhythm with a period of ~25 h next to the entrained 24 h rhythm. LDim did not affect body weight or glucose tolerance. In conclusion, we introduce the first rodent model for disturbed circadian control of sleep due to LAN. We show that internal desynchronization is possible in a 24 h L:D cycle which suggests that a similar desynchronization may explain the association between LAN and human insomnia. PMID:27762290

Surveying the Impact of Work Hours and Schedules on Commercial Motor Vehicle Driver Sleep

PubMed Central

Hege, Adam; Perko, Michael; Johnson, Amber; Yu, Chong Ho; Sönmez, Sevil; Apostolopoulos, Yorghos

2015-01-01

Background Given the long hours on the road involving multiple and interacting work stressors (i.e., delivery pressures, irregular shifts, ergonomic hazards), commercial drivers face a plethora of health and safety risks. Researchers goal was to determine whether and to what extent long-haul trucker work schedules influence sleep duration and quality. Methods Survey and biometric data collected from male long-haul truck drivers at a major truckstop in central North Carolina over a six month period. Results Daily hours worked (mean = 11 hours, 55 minutes) and frequency of working over government-mandated daily HOS regulations (23.8% “frequently or always”) were statistically significant predictors of sleep duration. Miles driven per week (mean = 2,812.61), irregular daily hours worked (63.8%), and frequency of working over the daily hour limit (23.8% “frequently or always”) were statistically significant predictors of sleep quality. Conclusion Implications of findings suggest a comprehensive review of the regulations and operational conditions for commercial motor vehicle drivers be undertaken. PMID:26106509

Optimizing sleep to maximize performance: implications and recommendations for elite athletes.

PubMed

Simpson, N S; Gibbs, E L; Matheson, G O

2017-03-01

Despite a growing body of literature demonstrating a positive relationship between sleep and optimal performance, athletes often have low sleep quality and quantity. Insufficient sleep among athletes may be due to scheduling constraints and the low priority of sleep relative to other training demands, as well as a lack of awareness of the role of sleep in optimizing athletic performance. Domains of athletic performance (e.g., speed and endurance), neurocognitive function (e.g., attention and memory), and physical health (e.g., illness and injury risk, and weight maintenance) have all been shown to be negatively affected by insufficient sleep or experimentally modeled sleep restriction. However, healthy adults are notoriously poor at self-assessing the magnitude of the impact of sleep loss, underscoring the need for increased awareness of the importance of sleep among both elite athletes and practitioners managing their care. Strategies to optimize sleep quality and quantity in athletes include approaches for expanding total sleep duration, improving sleep environment, and identifying potential sleep disorders. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sleep patterns in high school and university students: a longitudinal study.

PubMed

Urner, Martin; Tornic, Jure; Bloch, Konrad E

2009-08-01

We performed a longitudinal study to investigate whether changes in social zeitgebers and age alter sleep patterns in students during the transition from high school to university. Actimetry was performed on 24 high-school students (mean age+/-SD: 18.4+/-0.9 yrs; 12 females) for two weeks. Recordings were repeated in the same subjects 5 yrs later when they were university students. The sleep period duration and its center, the mid-sleep time, and total sleep time were estimated by actimetry. Actigraphic total sleep time was similar when in high school and at the university on school days (6.31+/-0.47 vs. 6.45+/-0.80 h, p = ns) and longer on leisure days by 1.10+/-1.10 h (p < 0.0001 vs. school days) when in high school, but not at the university. Compared to the high school situation, the mid-sleep time was delayed when at the university on school days (03:11+/-0.6 vs. 03:55+/-0.7 h, p < 0.0001), but not on leisure days. Individual mid-sleep times on school and leisure days when in high school were significantly correlated with the corresponding values 5 yrs later when at the university (r = 0.58 and r = 0.55, p < 0.05, respectively). The large differences in total sleep time between school and leisure days when students attended high school and the delayed mid-sleep time on school days when students attended university are consistent with a circadian phase shift due to changes in class schedules, other zeitgebers, and lifestyle preferences. Age-related changes may also have occurred, although some individuality of the sleep pattern was maintained during the 5 yr study span. These findings have important implications for optimizing school and work schedules in students of different age and level of education.

The Relative Impact of Sleep and Circadian Drive on Motor Skill Acquisition and Memory Consolidation.

PubMed

Tucker, Matthew A; Morris, Christopher J; Morgan, Alexandra; Yang, Jessica; Myers, Samantha; Pierce, Joanna Garcia; Stickgold, Robert; Scheer, Frank A J L

2017-04-01

Sleep during the biological night facilitates memory consolidation. Here we determined the impact of sleep and wake on motor skill learning (acquisition) and subsequent off-line skill improvement (memory consolidation), independent of circadian phase, and compared this to the impact of the endogenous circadian system, independent of whether sleep occurred during the biological night or day. Participants completed two 8-day sleep laboratory visits, adhering on one visit to a circadian aligned ("normal") sleep schedule for the full duration of the protocol, and on the other to a circadian misaligned (12-hour inverted) schedule, with alignment during the first 3 days, a 12-hour 'slam shift' on Day 4, followed by circadian misalignment during the last 4 days of the protocol. Participants were repeatedly trained and tested on different versions of the finger-tapping motor sequence task across each visit. Sleep facilitated offline memory consolidation regardless of whether it occurred during the biological day or night, while circadian phase had no significant impact. These sleep-related benefits remained after accounting for general motor speed, measured in the absence of learning. In addition, motor skill acquisition was facilitated when the training session followed shortly after sleep, without significant impact of circadian phase (biological morning vs. evening). This effect was largely driven by heightened acquisition in participants who slept during the day and were trained shortly thereafter, that is, when acquisition occurred during the biological evening. These benefits were also retained after controlling for general motor speed. Sleep benefits both the acquisition and consolidation of motor skill regardless of whether they occur during the biological day or night. After controlling for general motor speed, a critical adjustment that few studies perform, these sleep benefits remain intact. Our findings have clear implications for night shift workers who obtain their sleep during the day. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Sleep management and the performance of eight sailors in the Tour de France à la voile yacht race.

PubMed

Léger, D; Elbaz, M; Raffray, T; Metlaine, A; Bayon, V; Duforez, F

2008-01-01

We observed how sailors manage their sleep and alertness before and during competition in a long-haul yacht race. Global performance of the teams was also recorded. We assessed eight sailors aged 21-30 years, split into four teams, who competed in the Tour de France à la Voile 2002 yacht race. Two phases of the race were examined: two legs in both the Atlantic Ocean and Mediterranean Sea. Sleep length, sleep debt, and sleepiness before competition and on board during the race were assessed using ambulatory polysomnography. Intermediate and final rankings were considered as a reflection of performance. A significant correlation was observed between the sleep debt before competition and the total sleep time on board during the Atlantic legs. The greater the sleep debt, the more sleepy the participants were. During the Mediterranean legs, almost all the sailors were deprived of sleep and slept during the daytime competitions. We observed that the final ranking in the race related to the sleep management strategy of the participants. In extreme competitive conditions, the effect of a good night's sleep before competition on performance is important. The strategy of the winners was to get sufficient sleep before each leg so as to be the most alert and efficient during the race.

The Prickly Politics of School Starting Times.

ERIC Educational Resources Information Center

Wahlstrom, Kyla L.

1999-01-01

Tinkering with school schedules to accommodate adolescents' sleep patterns is politically risky. A University of Minnesota study analyzing stakeholders' attitudes toward later high school starting times showed that changing a school's schedule provokes as emotional a reaction as that of closing a school or changing its attendance area. Open…

The Heavy Vehicle Study: a case-control study investigating risk factors for crash in long distance heavy vehicle drivers in Australia

PubMed Central

2010-01-01

Background Heavy vehicle transportation continues to grow internationally; yet crash rates are high, and the risk of injury and death extends to all road users. The work environment for the heavy vehicle driver poses many challenges; conditions such as scheduling and payment are proposed risk factors for crash, yet the precise measure of these needs quantifying. Other risk factors such as sleep disorders including obstructive sleep apnoea have been shown to increase crash risk in motor vehicle drivers however the risk of heavy vehicle crash from this and related health conditions needs detailed investigation. Methods and Design The proposed case control study will recruit 1034 long distance heavy vehicle drivers: 517 who have crashed and 517 who have not. All participants will be interviewed at length, regarding their driving and crash history, typical workloads, scheduling and payment, trip history over several days, sleep patterns, health, and substance use. All participants will have administered a nasal flow monitor for the detection of obstructive sleep apnoea. Discussion Significant attention has been paid to the enforcement of legislation aiming to deter problems such as excess loading, speeding and substance use; however, there is inconclusive evidence as to the direction and strength of associations of many other postulated risk factors for heavy vehicle crashes. The influence of factors such as remuneration and scheduling on crash risk is unclear; so too the association between sleep apnoea and the risk of heavy vehicle driver crash. Contributory factors such as sleep quality and quantity, body mass and health status will be investigated. Quantifying the measure of effect of these factors on the heavy vehicle driver will inform policy development that aims toward safer driving practices and reduction in heavy vehicle crash; protecting the lives of many on the road network. PMID:20338064

Automated Planning and Scheduling for Space Mission Operations

NASA Technical Reports Server (NTRS)

Chien, Steve; Jonsson, Ari; Knight, Russell

2005-01-01

Research Trends: a) Finite-capacity scheduling under more complex constraints and increased problem dimensionality (subcontracting, overtime, lot splitting, inventory, etc.) b) Integrated planning and scheduling. c) Mixed-initiative frameworks. d) Management of uncertainty (proactive and reactive). e) Autonomous agent architectures and distributed production management. e) Integration of machine learning capabilities. f) Wider scope of applications: 1) analysis of supplier/buyer protocols & tradeoffs; 2) integration of strategic & tactical decision-making; and 3) enterprise integration.

Keeping the right time in space: importance of circadian clock and sleep for physiology and performance of astronauts.

PubMed

Guo, Jin-Hu; Qu, Wei-Min; Chen, Shan-Guang; Chen, Xiao-Ping; Lv, Ke; Huang, Zhi-Li; Wu, Yi-Lan

2014-01-01

The circadian clock and sleep are essential for human physiology and behavior; deregulation of circadian rhythms impairs health and performance. Circadian clocks and sleep evolved to adapt to Earth's environment, which is characterized by a 24-hour light-dark cycle. Changes in gravity load, lighting and work schedules during spaceflight missions can impact circadian clocks and disrupt sleep, in turn jeopardizing the mood, cognition and performance of orbiting astronauts. In this review, we summarize our understanding of both the influence of the space environment on the circadian timing system and sleep and the impact of these changes on astronaut physiology and performance.

Sleep Misperception and Chronic Insomnia in the General Population: The Role of Objective Sleep Duration and Psychological Profiles

PubMed Central

Fernandez-Mendoza, Julio; Calhoun, Susan L.; Bixler, Edward O.; Karataraki, Maria; Liao, Duanping; Vela-Bueno, Antonio; Ramos-Platon, María Jose; Sauder, Katherine A.; Basta, Maria; Vgontzas, Alexandros N.

2011-01-01

Objective Sleep misperception is considered by some investigators a common characteristic of chronic insomnia, whereas others propose it as a separate diagnosis. The frequency and the determinants of sleep misperception in general population samples are unknown. In this study we examined the role of objective sleep duration, a novel marker in phenotyping insomnia, and psychological profiles on sleep misperception in a large, general population sample. Methods 142 insomniacs and 724 controls selected from a general random sample of 1,741 individuals (age ≥ 20 years) underwent a polysomnographic evaluation, completed the Minnesota Multiphasic Personality Inventory-2, and were split into two groups based on their objective sleep duration: “normal sleep duration” (≥ 6 hours) and “short sleep duration” (< 6 hours). Results The discrepancy between subjective and objective sleep duration was determined by two independent factors. Short sleepers reported more sleep than they objectively had and insomniacs reported less sleep than controls with similar objective sleep duration. The additive effect of these two factors resulted in underestimation only in insomniacs with normal sleep duration. Insomniacs with normal sleep duration showed a MMPI-2 profile of high depression and anxiety, and low ego strength, whereas insomniacs with short sleep duration showed a profile of a medical disorder. Conclusions Underestimation of sleep duration is prevalent among insomniacs with objective normal sleep duration. Anxious-ruminative traits and poor resources for coping with stress appear to mediate the underestimation of sleep duration. These data further support the validity and clinical utility of objective sleep measures in phenotyping insomnia. PMID:20978224

The Efficacy of a Chinstrap in Treating Sleep Disordered Breathing and Snoring

PubMed Central

Bhat, Sushanth; Gushway-Henry, Neola; Polos, Peter G.; DeBari, Vincent A.; Riar, Sandeep; Gupta, Divya; Lysenko, Liudmila; Patel, Disha; Pi, Justin; Chokroverty, Sudhansu

2014-01-01

Study Objectives: A previously published case report suggested that a chinstrap alone might improve obstructive sleep apnea (OSA). We conducted this study to determine whether a chinstrap was a feasible alternative to continuous positive airway pressure (CPAP) in patients with OSA. Methods: 26 adult patients with OSA (apnea-hypopnea index [AHI] > 5/h on diagnostic polysomnogram [PSG]) underwent a modified split-night PSG, using only a chinstrap for the first 2 hours of sleep, followed by CPAP titration for the remainder of the night. Improvements in AHI, arterial oxygen saturation (SpO2), and snoring with chinstrap use were compared to results with optimal CPAP pressures. Results: There was no significant difference between the diagnostic PSG and the chinstrap portion of the split-night PSG in the following parameters: general AHI (median [IQR] 16.0/h [9.7-26.0] vs. 25.9/h [10.7-42.7]), SpO2 nadir (84.0% [80.5-87.5] vs. 87.0 [84.0-88.5]), AHI in REM sleep (26.7/h [16.8-43.7] vs. 42.4/h [21.3-57.7]), AHI in supine sleep (24.9/h [11.9-51.5] vs. 29.8/h [11.7-55.5]), snoring index (253.2/h [147.5-353.1] vs. 180.0/h [9.8-393.3]) or subjective snoring scale (3.0 [0.8-3.0] vs. 2.5 [0.4-3.0]). The AHI and SpO2 nadir in the 13 patients with mild OSA also did not improve with chinstrap use (9.6/h [8.1-12.2] vs. 10.6/h [6.8-35.4] and 87.0% [83.0-90.0] vs. 88.0% [87.0-89.0]). All these parameters showed significant improvement with optimal CPAP titration (p < 0.05). Conclusions: A chinstrap alone is not an effective treatment for OSA. It does not improve sleep disordered breathing, even in mild OSA, nor does it improve the AHI in REM sleep or supine sleep. It is also ineffective in improving snoring. Citation: Bhat S, Gushway-Henry N, Polos PG, DeBari VA, Riar S, Gupta D, Lysenko L, Patel D, Pi J, Chokroverty S. The efficacy of a chinstrap in treating sleep disordered breathing and snoring. J Clin Sleep Med 2014;10(8):887-892. PMID:25126035

Population dynamics of Varroa destructor (Acari: Varroidae) in commercial honey bee colonies and implications for control

USDA-ARS?s Scientific Manuscript database

Treatment schedules to maintain low levels of Varroa mites in honey bee colonies were tested in hives started from either package bees or splits of larger colonies. The schedules were developed based on predictions of Varroa population growth generated from a mathematical model of honey bee colony ...

The Value of Sleep on Athletic Performance, Injury, and Recovery in the Young Athlete.

PubMed

Copenhaver, Elizabeth A; Diamond, Alex B

2017-03-01

Adequate sleep can easily become compromised as student-athletes try to balance the multiple demands on their time. People with sleep deficiency are at increased risk for acute illnesses, traumatic sports injuries, and development of chronic diseases. Training sessions or competitions during extremely early or late hours can interfere with circadian and homeostatic rhythms. Adjusting the training schedule to improve sleep duration has a significantly positive impact on several aspects of athletic performance. Pediatricians should increase the time dedicated in well-child visits for sleep hygiene and evaluate for sleep disorders at all ages. Parents, coaching staff, teachers, and pediatricians should advocate for improved education on the importance of sleep during adolescence. Future sleep research specific to adolescent athletes can further delineate requirements specific to sport, gender, training times, and surrounding competitions. [Pediatr Ann. 2017;46(3):e106-e111.]. Copyright 2017, SLACK Incorporated.

The impact of shift work on nurses' job stress, sleep quality and self-perceived health status.

PubMed

Lin, Shu-Hui; Liao, Wen-Chun; Chen, Mei-Yen; Fan, Jun-Yu

2014-07-01

The aim of this study was to describe the current state of nurses' shift work in Taiwan and how it affects nurses' stress, sleep quality and self-perceived health status. To enable the provision of 24-hour patient care, nurses need to work various shifts. Long-term shift work significantly affects nurses' overall physical and mental health. Nurses from four Chiayi County district hospitals in Taiwan (n = 266) participated in this cross-sectional study from August to September 2010. Demographics, work schedule forms, a stress checklist, a sleep-quality measure and a health-status measure were used to collect data. Independent t-test, one-way anova, Pearson's r, and hierarchical regression were applied for analysis. The results showed that regardless of the amount of shift work they performed, nurses reported moderate job stress, poor sleep quality and moderate self-perceived health. The following significant relationships were observed: job stress was inversely related to sleep quality, which was directly related to self-perceived health status. Hospital managers need to ensure more healthy shift work scheduling in order to improve nurses' clinical performance and personal health status, thereby also improving the quality of patient care. © 2012 John Wiley & Sons Ltd.

Regularity in the control of the free-running sleep-wakefulness rhythm

NASA Technical Reports Server (NTRS)

Webb, W. B.; Agnew, H. W., Jr.

1974-01-01

In the present experiment, rigid control over the sleep and wake-up times was employed in an attempt to contain the natural rhythm to a 24-hr cycle. Eight subjects were isolated from all time and social cues for 10 days. They were placed on a rigid schedule of sleep between 11 p.m. and 7 a.m. The results indicate that, for practical purposes, the free-running sleep-wakefulness rhythm can be contained to a 24-hr cycle by rigid control of the sleep portion of the cycle. When part of the control was released by allowing the subjects to sleep beyond 7 a.m., they slept an average of 67 min longer and showed sleep latencies which averaged 73 min. From these data it is concluded that control of the sleep portion of the sleep-wakefulness cycle, particularly control of the wake-up time, is sufficient to contain the free-running sleep-wakefulness rhythm to a 24-hr cycle.

Incidence of sleep pattern disturbance (SPD) in a hemodialysis sample.

PubMed

Strangio, D; Locking-Cusolito, H

1999-01-01

Personal experience suggests that sleep pattern disturbance (SPD) is a serious problem for the patients we serve. The purpose of this study was to identify the scope of sleep problems among all willing patients in a medium-sized hemodialysis unit in a university teaching centre. This descriptive study examined SPD through the use of a sleep diary that subjects were asked to complete each morning for a week. Subjects were asked to describe sleep latency, sleep quantity, number of arousals, whether they awoke feeling rested, factors that interfered with sleep the night before, and sleep inducers employed the night before. They were also asked to record their dialysis schedule. Each subject's chart was reviewed with respect to medications and evidence of other medical problems that interfered with sleep. Findings were benchmarked with results from the literature. Information regarding facilitators and barriers to sleep has provided some basis for an interdisciplinary plan of care to address this distressing problem.

Light treatment for NASA shiftworkers.

PubMed

Stewart, K T; Hayes, B C; Eastman, C I

1995-04-01

Intense artificial light can phase-shift circadian rhythms and improve performance, sleep, and well-being during shiftwork simulations. In real shiftworkers, however, exposure to sunlight and other time cues may decrease the efficacy of light treatment, and occupational and family responsibilities may make it impractical. With these considerations in mind, we designed and tested light-treatment protocols for NASA personnel who worked on shifted schedules during two Space Shuttle missions. During the prelaunch week, treatment subjects self-administered light of approximately 10,000 lux at times of day that phase-delay circadian rhythms. Treatment continued during the missions and for several days afterward. No treatment was administered to subjects in the control group. Treatment subjects reported better sleep, performance, and physical and emotional well-being than control subjects and rated the treatment as highly effective for promoting adjustment to their work schedules. Light treatment is both feasible and beneficial for NASA personnel who must work on shifted schedules during Space Shuttle missions.

The efficacy of a chinstrap in treating sleep disordered breathing and snoring.

PubMed

Bhat, Sushanth; Gushway-Henry, Neola; Polos, Peter G; DeBari, Vincent A; Riar, Sandeep; Gupta, Divya; Lysenko, Liudmila; Patel, Disha; Pi, Justin; Chokroverty, Sudhansu

2014-08-15

A previously published case report suggested that a chinstrap alone might improve obstructive sleep apnea (OSA). We conducted this study to determine whether a chinstrap was a feasible alternative to continuous positive airway pressure (CPAP) in patients with OSA. 26 adult patients with OSA (apnea-hypopnea index [AHI] > 5/h on diagnostic polysomnogram [PSG]) underwent a modified split-night PSG, using only a chinstrap for the first 2 hours of sleep, followed by CPAP titration for the remainder of the night. Improvements in AHI, arterial oxygen saturation (SpO2), and snoring with chinstrap use were compared to results with optimal CPAP pressures. There was no significant difference between the diagnostic PSG and the chinstrap portion of the split-night PSG in the following parameters: general AHI (median [IQR] 16.0/h [9.7-26.0] vs. 25.9/h [10.7-42.7]), SpO2 nadir (84.0% [80.5-87.5] vs. 87.0 [84.0-88.5]), AHI in REM sleep (26.7/h [16.8-43.7] vs. 42.4/h [21.3-57.7]), AHI in supine sleep (24.9/h [11.9-51.5] vs. 29.8/h [11.7-55.5]), snoring index (253.2/h [147.5-353.1] vs. 180.0/h [9.8-393.3]) or subjective snoring scale (3.0 [0.8-3.0] vs. 2.5 [0.4-3.0]). The AHI and SpO2 nadir in the 13 patients with mild OSA also did not improve with chinstrap use (9.6/h [8.1-12.2] vs. 10.6/h [6.8-35.4] and 87.0% [83.0-90.0] vs. 88.0% [87.0-89.0]). All these parameters showed significant improvement with optimal CPAP titration (p < 0.05). A chinstrap alone is not an effective treatment for OSA. It does not improve sleep disordered breathing, even in mild OSA, nor does it improve the AHI in REM sleep or supine sleep. It is also ineffective in improving snoring.

Project Helps High-Schoolers Shore up on Shut-Eye

ERIC Educational Resources Information Center

Brydolf, Carol

2011-01-01

It's not news to most parents of adolescents that teenagers' sleep cycles operate in an alternate universe. A growing body of research shows that American teenagers are so at odds with conventional work and school schedules that they suffer from sleep deficits serious enough to affect their moods, health, and academic performance. Yet the vast…

Circadian rhythms, sleep, and performance in space.

PubMed

Mallis, M M; DeRoshia, C W

2005-06-01

Maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the National Aeronautics and Space Administration's (NASA's) vision "to extend humanity's reach to the Moon, Mars and beyond" to become a reality. Field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. This paper documents evidence of significant sleep loss and disruption of circadian rhythms in astronauts and associated performance decrements during several space missions, which demonstrates the need to develop effective countermeasures. Both sleep and circadian disruptions have been identified in the Behavioral Health and Performance (BH&P) area and the Advanced Human Support Technology (AHST) area of NASA's Bioastronautics Critical Path Roadmap. Such disruptions could have serious consequences on the effectiveness, health, and safety of astronaut crews, thus reducing the safety margin and increasing the chances of an accident or incident. These decrements oftentimes can be difficult to detect and counter effectively in restrictive operational environments. NASA is focusing research on the development of optimal sleep/wake schedules and countermeasure timing and application to help mitigate the cumulative effects of sleep and circadian disruption and enhance operational performance. Investing research in humans is one of NASA's building blocks that will allow for both short- and long-duration space missions and help NASA in developing approaches to manage and overcome the human limitations of space travel. In addition to reviewing the current state of knowledge concerning sleep and circadian disruptions during space operations, this paper provides an overview of NASA's broad research goals. Also, NASA-funded research, designed to evaluate the relationships between sleep quality, circadian rhythm stability, and performance proficiency in both ground-based simulations and space mission studies, as described in the 2003 NASA Task Book, will be reviewed.

Sunlight Exposure, Work Hours, Caffeine Consumption, and Sleep Duration in the Naval Environment.

PubMed

Shattuck, Nita L; Matsangas, Panagiotis

2017-06-01

Sailors in the U.S. Navy are habitual shiftworkers, often experiencing circadian misalignment due to their irregular work/rest schedules. This study assessed the effect of sunlight exposure, work hours, and caffeinated beverage consumption on the daily sleep duration of crewmembers of a U.S. Navy ship during a 2-wk underway period. Working in an artificially lit area with no access to sunlight during work hours, U.S. Navy crew members (N = 91) used daily logs to report their daily activity, caffeinated beverage consumption, and exposure to sunlight while off-duty; sleep was assessed by wrist-worn actigraphy. Hours of sunlight exposure, work duration, and the amount of coffee/tea/soft drinks were statistically significant predictors of sleep duration. On average, crewmembers who reported more than one half-hour of sunlight each day slept on average ∼40 min (10%) less than their peers working the same shifts who received less than one half-hour of sunlight (on average 6.05 ± 0.90 h vs. 6.71 ± 0.91 h, respectively). Exposure to sunlight, work hours, and consumption of caffeinated beverages are important factors when planning watchstanding schedules at sea. Even though further research is needed, our results suggest that even brief exposure to sunlight may contribute to circadian misalignment that negatively affects sleep in the operational environment. Educating crewmembers about sleep hygiene, especially the important roles played by sunlight and caffeine, could potentially improve the sleep and fatigue levels of this population of maritime shiftworkers.Shattuck NL, Matsangas P. Sunlight exposure, work hours, caffeine consumption, and sleep duration in the naval environment. Aerosp Med Hum Perform. 2017; 88(6):579-585.

Circadian rhythms, sleep, and performance in space

NASA Technical Reports Server (NTRS)

Mallis, M. M.; DeRoshia, C. W.

2005-01-01

Maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the National Aeronautics and Space Administration's (NASA's) vision "to extend humanity's reach to the Moon, Mars and beyond" to become a reality. Field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. This paper documents evidence of significant sleep loss and disruption of circadian rhythms in astronauts and associated performance decrements during several space missions, which demonstrates the need to develop effective countermeasures. Both sleep and circadian disruptions have been identified in the Behavioral Health and Performance (BH&P) area and the Advanced Human Support Technology (AHST) area of NASA's Bioastronautics Critical Path Roadmap. Such disruptions could have serious consequences on the effectiveness, health, and safety of astronaut crews, thus reducing the safety margin and increasing the chances of an accident or incident. These decrements oftentimes can be difficult to detect and counter effectively in restrictive operational environments. NASA is focusing research on the development of optimal sleep/wake schedules and countermeasure timing and application to help mitigate the cumulative effects of sleep and circadian disruption and enhance operational performance. Investing research in humans is one of NASA's building blocks that will allow for both short- and long-duration space missions and help NASA in developing approaches to manage and overcome the human limitations of space travel. In addition to reviewing the current state of knowledge concerning sleep and circadian disruptions during space operations, this paper provides an overview of NASA's broad research goals. Also, NASA-funded research, designed to evaluate the relationships between sleep quality, circadian rhythm stability, and performance proficiency in both ground-based simulations and space mission studies, as described in the 2003 NASA Task Book, will be reviewed.

Emotional trait and memory associates of sleep timing and quality

PubMed Central

Pace-Schott, Edward F.; Rubin, Zoe S.; Tracy, Lauren E.; Spencer, Rebecca M.C.; Orr, Scott P.; Verga, Patrick W.

2015-01-01

Poor ability to remember the extinction of conditioned fear, elevated trait anxiety, and delayed or disrupted nocturnal sleep are reported in anxiety disorders. The current study examines the interrelationship of these factors in healthy young-adult males. Skin- conductance response was conditioned to two differently colored lamps. One color but not the other was then extinguished. After varying delays, both colors were presented to determine extinction recall and generalization. Questionnaires measured sleep quality, morningness - eveningness, neuroticism and trait anxiety. A subset produced a mean 7.0 nights of actigraphy and sleep diaries. Median split of mean sleep midpoint defined early-and late-”sleep timers”. Extinction was more rapidly learned in the morning than evening only in early-timers, who also better generalized extinction recall. Extinction recall was greater with higher sleep efficiency. Sleep efficiency and morningness were negatively associated with neuroticism and anxiety. However, neuroticism and anxiety did not predict extinction learning, recall or generalization. Therefore, neuroticism/anxiety and deficient fear extinction, although both associated with poor quality and late timing of sleep, are not directly associated with each other. Elevated trait anxiety, in addition to predisposing directly to anxiety disorders, may thus also indirectly promote such disorders by impairing sleep and, consequently, extinction memory. PMID:26257092

Emotional trait and memory associates of sleep timing and quality.

PubMed

Pace-Schott, Edward F; Rubin, Zoe S; Tracy, Lauren E; Spencer, Rebecca M C; Orr, Scott P; Verga, Patrick W

2015-10-30

Poor ability to remember the extinction of conditioned fear, elevated trait anxiety, and delayed or disrupted nocturnal sleep are reported in anxiety disorders. The current study examines the interrelationship of these factors in healthy young-adult males. Skin-conductance response was conditioned to two differently colored lamps. One color but not the other was then extinguished. After varying delays, both colors were presented to determine extinction recall and generalization. Questionnaires measured sleep quality, morningness-eveningness, neuroticism and trait anxiety. A subset produced a mean 7.0 nights of actigraphy and sleep diaries. Median split of mean sleep midpoint defined early- and late-"sleep timers". Extinction was more rapidly learned in the morning than evening only in early timers who also better generalized extinction recall. Extinction recall was greater with higher sleep efficiency. Sleep efficiency and morningness were negatively associated with neuroticism and anxiety. However, neuroticism and anxiety did not predict extinction learning, recall or generalization. Therefore, neuroticism/anxiety and deficient fear extinction, although both associated with poor quality and late timing of sleep, are not directly associated with each other. Elevated trait anxiety, in addition to predisposing directly to anxiety disorders, may thus also indirectly promote such disorders by impairing sleep and, consequently, extinction memory. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A video method to study Drosophila sleep.

PubMed

Zimmerman, John E; Raizen, David M; Maycock, Matthew H; Maislin, Greg; Pack, Allan I

2008-11-01

To use video to determine the accuracy of the infrared beam-splitting method for measuring sleep in Drosophila and to determine the effect of time of day, sex, genotype, and age on sleep measurements. A digital image analysis method based on frame subtraction principle was developed to distinguish a quiescent from a moving fly. Data obtained using this method were compared with data obtained using the Drosophila Activity Monitoring System (DAMS). The location of the fly was identified based on its centroid location in the subtracted images. The error associated with the identification of total sleep using DAMS ranged from 7% to 95% and depended on genotype, sex, age, and time of day. The degree of the total sleep error was dependent on genotype during the daytime (P < 0.001) and was dependent on age during both the daytime and the nighttime (P < 0.001 for both). The DAMS method overestimated sleep bout duration during both the day and night, and the degree of these errors was genotype dependent (P < 0.001). Brief movements that occur during sleep bouts can be accurately identified using video. Both video and DAMS detected a homeostatic response to sleep deprivation. Video digital analysis is more accurate than DAMS in fly sleep measurements. In particular, conclusions drawn from DAMS measurements regarding daytime sleep and sleep architecture should be made with caution. Video analysis also permits the assessment of fly position and brief movements during sleep.

Sleep-wake habits and circadian preference in Mexican secondary school.

PubMed

Arrona-Palacios, Arturo; García, Aída; Valdez, Pablo

2015-10-01

The current study aimed to determine the differences between sleep-wake habits and circadian preference in Mexican adolescents attending classes at a morning shift or an afternoon shift. The sample consisted of 568 students of a secondary school in Reynosa, northeastern Mexico, of whom 280 were boys and 288 were girls (mean age 14.08 ± 0.72 years, age range 13-16 years). In the morning shift, 287 students attend classes on a schedule from 7:30 to 13:00 and the afternoon shift, 281 students, on a schedule from 13:20 to 19:00. Students completed a general information questionnaire, the Sleep Timing Questionnaire and the Spanish version of the Morningness-Eveningness Questionnaire. The adolescents who attended the morning shift had earlier bedtime and waking time, but shorter sleep duration than those who attended the afternoon shift. Those oriented to eveningness had later bedtime, waking time, and a shorter sleep duration than those oriented to morningness. Two interactions were found between school shift and chronotype. First, with regard to waking time during weekdays, students who attended the afternoon shift and were oriented to eveningness woke up later than those who attended the morning shift and were oriented to eveningness; during weekdays, there were no differences between the waking time of morning-type and evening-type students who attended the morning shift. Second, with regard to sleep duration on weekdays, students who attended the morning shift and were oriented to eveningness had the shortest sleep duration. Furthermore, there were no differences between sleep duration on weekdays in evening-type and morning-type students of the afternoon shift. Adolescents who attend classes in the morning shift and are oriented to eveningness are the most sleep deprived. Those who attend the afternoon shift will have optimal sleep duration, regardless of their circadian preference. Copyright © 2015 Elsevier B.V. All rights reserved.

Shift Work in Nurses: Contribution of Phenotypes and Genotypes to Adaptation

PubMed Central

Gamble, Karen L.; Motsinger-Reif, Alison A.; Hida, Akiko; Borsetti, Hugo M.; Servick, Stein V.; Ciarleglio, Christopher M.; Robbins, Sam; Hicks, Jennifer; Carver, Krista; Hamilton, Nalo; Wells, Nancy; Summar, Marshall L.; McMahon, Douglas G.; Johnson, Carl Hirschie

2011-01-01

Background Daily cycles of sleep/wake, hormones, and physiological processes are often misaligned with behavioral patterns during shift work, leading to an increased risk of developing cardiovascular/metabolic/gastrointestinal disorders, some types of cancer, and mental disorders including depression and anxiety. It is unclear how sleep timing, chronotype, and circadian clock gene variation contribute to adaptation to shift work. Methods Newly defined sleep strategies, chronotype, and genotype for polymorphisms in circadian clock genes were assessed in 388 hospital day- and night-shift nurses. Results Night-shift nurses who used sleep deprivation as a means to switch to and from diurnal sleep on work days (∼25%) were the most poorly adapted to their work schedule. Chronotype also influenced efficacy of adaptation. In addition, polymorphisms in CLOCK, NPAS2, PER2, and PER3 were significantly associated with outcomes such as alcohol/caffeine consumption and sleepiness, as well as sleep phase, inertia and duration in both single- and multi-locus models. Many of these results were specific to shift type suggesting an interaction between genotype and environment (in this case, shift work). Conclusions Sleep strategy, chronotype, and genotype contribute to the adaptation of the circadian system to an environment that switches frequently and/or irregularly between different schedules of the light-dark cycle and social/workplace time. This study of shift work nurses illustrates how an environmental “stress” to the temporal organization of physiology and metabolism can have behavioral and health-related consequences. Because nurses are a key component of health care, these findings could have important implications for health-care policy. PMID:21533241

Sleep duration as a mediator between an alternating day and night shift work schedule and metabolic syndrome among female hospital employees.

PubMed

Korsiak, Jill; Tranmer, Joan; Day, Andrew; Aronson, Kristan J

2018-02-01

The main objective was to determine whether sleep duration on work shifts mediates the relationship between a current alternating day and night shift work schedule and metabolic syndrome among female hospital employees. The secondary objective was to assess whether cumulative lifetime shift work exposure was associated with metabolic syndrome. In this cross-sectional study of 294 female hospital employees, sleep duration was measured with the ActiGraph GT3X+. Shift work status was determined through self-report. Investigation of the total, direct and indirect effects between shift work, sleep duration on work shifts and metabolic syndrome was conducted using regression path analysis. Logistic regression was used to determine the association between cumulative shift work exposure and metabolic syndrome. Shift work is strongly associated with metabolic syndrome (OR Total =2.72, 95% CI 1.38 to 5.36), and the relationship is attenuated when work shift sleep duration is added to the model (OR Direct =1.18, 95% CI 0.49 to 2.89). Sleep duration is an important intermediate between shift work and metabolic syndrome (OR Indirect =2.25, 95% CI 1.27 to 4.26). Cumulative shift work exposure is not associated with metabolic syndrome in this population. Sleep duration mediates the association between a current alternating day-night shift work pattern and metabolic syndrome. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Light as a chronobiologic countermeasure for long-duration space operations

NASA Technical Reports Server (NTRS)

Samel, Alexander (Editor); Gander, Philippa (Editor); Evans, Julie; Graeber, R. Curtis; Hackett, Elizabeth; Keil, Lanny; Maab, Hartmut; Raabe, Wolfgang; Rosekind, Mark; Rountree, Mike

1991-01-01

Long-duration space missions require adaptation to work-rest schedules which are substantially shifted with respect to earth. Astronauts are expected to work in two-shift operations and the environmental synchronizers (zeitgebers) in a spacecraft differ significantly from those on earth. A study on circadian rhythms, sleep, and performance was conducted by exposing four subjects to 6 deg head-down tilt bedrest (to simulate the effects of the weightless condition) and imposing a 12-h shift (6 h delay per day for two days). Bright light was tested in a cross-over design as a countermeasure for achieving faster resynchronization and regaining stable conditions for sleep and circadian rhythmicity. Data collection included objective sleep recording, temperature, heart rate, and excretion of hormones and electrolytes as well as performance and responses to questionnaires. Even without a shift in the sleep-wake cycle, the sleep quantity, circadian amplitudes and 24 h means decreased in many functions under bedrest conditions. During the shift days, sleepiness and fatigue increased, and alertness decreased. However, sleep quantity was regained, and resynchronization was completed within seven days after the shift for almost all functions, irrespective of whether light was administered during day-time or night-time hours. The time of day of light exposure surprisingly appeared not to have a discriminatory effect on the resynchronization speed under shift and bedrest conditions. The results indicate that simulated weightlessness alters circadian rhythms and sleep, and that schedule changes induce additional physiological disruption with decreased subjective alertness and increased fatigue. Because of their operational implications, these phenomena deserve additional investigation.

Control Channel Vulnerability Analysis of the Institute of Electrical and Electronics Engineers 802.16m-2011 and 802.16- 2009 Standards

DTIC Science & Technology

2012-09-01

scheduler to adapt its uplink and downlink assignments to channel conditions. Sleep mode is used by the MS to minimize power drain and radio...is addressed in one resource unit, while for multi-user (MU) schemes , multiple users can be scheduled in one resource unit. Open-loop techniques...17  7.  Mobility and Power Management ......................................... 18  8.  Scheduling Services

Biomonitoring of physiological status and cognitive performance of underway submariners undergoing a novel watch-standing schedule

NASA Astrophysics Data System (ADS)

Duplessis, C. A.; Cullum, M. E.; Crepeau, L. J.

2005-05-01

Submarine watch-standers adhere to a 6 hour-on, 12 hour-off (6/12) watch-standing schedule, yoking them to an 18-hr day, engendering circadian desynchronization and chronic sleep deprivation. Moreover, the chronic social crowding, shift work, and confinement of submarine life provide additional stressors known to correlate with elevated secretory immunoglobulin A (sIgA) and cortisol levels, reduced performance, immunologic dysfunction, malignancies, infections, gastrointestinal illness, coronary disease, anxiety, and depression. We evaluated an alternative, compressed, fixed work schedule designed to enhance circadian rhythm entrainment, sleep hygiene, performance, and health on 10 underway submariners, who followed the alternative and 6/12 schedules for approximately 2 weeks each. We measured subjects" sleep, cognitive performance, and salivary biomarker levels. Pilot analysis of the salivary data on one subject utilizing ELISA suggests elevated biomarker levels of stress. Average PM cortisol levels were 0.2 μg/L (normal range: nondetectable - 0.15 μg/L), and mean sIgA levels were 562 μg/ml (normal range: 100-500 μg/ml). Future research exploiting real-time salivary bioassays, via fluorescent polarimetry technology, identified by the Office of Naval Research (ONR) as a future Naval requirement, allows researchers to address correlations between stress-induced elaboration of salivary biomarkers with physiological and performance decrements, thereby fostering insight into the underway submariner"s psychoimmunological status. This may help identify strategies that enhance resilience to stressors. Specifically, empirically-based modeling can identify optimal watch-standing schedules and stress-mitigating procedures -- within the operational constraints of the submarine milieu and the mission --that foster improved circadian entrainment and reduced stress reactivity, enhancing physiological health, operational performance, safety, and job satisfaction.

Sleep-related Issues for Recovery and Performance in Athletes.

PubMed

Kölling, Sarah; Duffield, Rob; Erlacher, Daniel; Venter, Ranel; Halson, Shona L

2018-04-13

The body of research that reports the relevance of sleep in high-performance sports is growing steadily. While the identification of sleep cycles and diagnosis of sleep disorders is limited to lab-based assessment via polysomnography, the development of activity-based devices estimating sleep patterns provides greater insight into the sleep behaviour of athletes in ecological settings. Overall, small sleep quantity and/or poor quality appears to exist in many athletic populations, though this may be related to training and competition context. Typical sleep-affecting factors are the scheduling of training sessions and competitions as well as impaired sleep-onset as a result of increased arousal prior to competition or due to the use of electronic devices before bedtime. Further challenges are travel demands which may be accompanied by jet-lag symptoms and disruption of sleep habits. Promotion of sleep may be approached via behavioural strategies, such as sleep hygiene, extending night-time sleep or daytime napping. Pharmacological interventions should be limited to clinically-induced treatments as evidence among healthy and athletic populations is lacking. To optimise and manage sleep in athletes, it is recommended to implement routine sleep monitoring on an individual basis.

Estimation of sleep status in sleep apnea patients using a novel head actigraphy technique.

PubMed

Hummel, Richard; Bradley, T Douglas; Fernie, Geoff R; Chang, S J Isaac; Alshaer, Hisham

2015-01-01

Polysomnography is a comprehensive modality for diagnosing sleep apnea (SA), but it is expensive and not widely available. Several technologies have been developed for portable diagnosis of SA in the home, most of which lack the ability to detect sleep status. Wrist actigraphy (accelerometry) has been adopted to cover this limitation. However, head actigraphy has not been systematically evaluated for this purpose. Therefore, the aim of this study was to evaluate the ability of head actigraphy to detect sleep/wake status. We obtained full overnight 3-axis head accelerometry data from 75 sleep apnea patient recordings. These were split into training and validation groups (2:1). Data were preprocessed and 5 features were extracted. Different feature combinations were fed into 3 different classifiers, namely support vector machine, logistic regression, and random forests, each of which was trained and validated on a different subgroup. The random forest algorithm yielded the highest performance, with an area under the receiver operating characteristic (ROC) curve of 0.81 for detection of sleep status. This shows that this technique has a very good performance in detecting sleep status in SA patients despite the specificities in this population, such as respiration related movements.

The indications for polysomnography and related procedures.

PubMed

Chesson, A L; Ferber, R A; Fry, J M; Grigg-Damberger, M; Hartse, K M; Hurwitz, T D; Johnson, S; Kader, G A; Littner, M; Rosen, G; Sangal, R B; Schmidt-Nowara, W; Sher, A

1997-06-01

This paper is a review of the literature on the use of polysomnography in the diagnosis of sleep disorders in the adult. It is based on a search of MEDLINE from January 1966 through April 1996. It has been reviewed and approved by the Board of Directors of the American Sleep Disorders Association and provides the background for the accompanying ASDA Standards of Practice Committee's Parameters for the Practice of Sleep Medicine in North America. The diagnostic categories reviewed are: sleep-related breathing disorders; other respiratory disorders; narcolepsy; parasomnias and sleep-related epilepsy; restless legs syndrome and periodic limb movement disorders: insomnia; and circadian rhythm sleep disorders. Where appropriate, previously published practice parameters papers are cited and discussed. The relevant published peer-reviewed literature used as the basis for critical decisions was compiled into accompanying evidence tables and is analyzed in the text. In the section on the assessment of sleep apnea syndrome, options for estimating pretest probability to select high risk patients are also reviewed. Sleep-testing procedures other than standard polysomnography are also addressed (daytime polysomnography, split-night studies, oximetry, limited full respiratory recordings, and less-than-full respiratory recording) and treatment-related follow-up studies are discussed.

Occupational and socioeconomic differences in actigraphically measured sleep.

PubMed

Takahashi, Masaya; Tsutsumi, Akizumi; Kurioka, Sumiko; Inoue, Akiomi; Shimazu, Akihito; Kosugi, Yuki; Kawakami, Norito

2014-08-01

Occupational conditions, together with socioeconomic status, may modulate sleep. This study examined the association of occupational conditions and socioeconomic status with actigraphic measures of sleep in workers. Fifty-five employees (40 ± 12 years) wore a wrist actigraph during sleep for seven consecutive nights. Sleep variables addressed included total sleep time, sleep efficiency, mean activity during sleep, sleep-onset latency, and wake after sleep onset. We also measured household income, occupational class, work schedule, weekly work hours, job demand, job control, worksite social support, effort-reward imbalance, organizational justice, and workplace social capital. Multiple linear regression models were used to determine the association of occupational indicators, socioeconomic status, as well as age and gender with each sleep variable. Higher workplace social capital was associated consistently with longer total sleep time (P < 0.001), higher sleep efficiency (P < 0.05) and lower mean activity during sleep (P < 0.07). Low occupational class (P < 0.01), higher job demand (P < 0.05) and lower job control (P < 0.05) were associated with longer total sleep time. No associations were significant for sleep-onset latency or wake after sleep onset. These preliminary results suggest that enhanced workplace social capital is closely associated with better quality and quantity of sleep. © 2014 European Sleep Research Society.

Sleep and circadian disruption and incident breast cancer risk: An evidence-based and theoretical review.

PubMed

Samuelsson, Laura B; Bovbjerg, Dana H; Roecklein, Kathryn A; Hall, Martica H

2018-01-01

Opportunities for restorative sleep and optimal sleep-wake schedules are becoming luxuries in industrialized cultures, yet accumulating research has revealed multiple adverse health effects of disruptions in sleep and circadian rhythms, including increased risk of breast cancer. The literature on breast cancer risk has focused largely on adverse effects of night shift work and exposure to light at night (LAN), without considering potential effects of associated sleep disruptions. As it stands, studies on breast cancer risk have not considered the impact of both sleep and circadian disruption, and the possible interaction of the two through bidirectional pathways, on breast cancer risk in the population at large. We review and synthesize this literature, including: 1) studies of circadian disruption and incident breast cancer; 2) evidence for bidirectional interactions between sleep and circadian systems; 3) studies of sleep and incident breast cancer; and 4) potential mechanistic pathways by which interrelated sleep and circadian disruption may contribute to the etiology of breast cancer. Copyright © 2017. Published by Elsevier Ltd.

Contributing influences of work environment on sleep quantity and quality of nursing assistants in long-term care facilities: A cross-sectional study

PubMed Central

Zhang, Yuan; Punnett, Laura; McEnany, Geoffry Phillips; Gore, Rebecca

2018-01-01

The effect of shift work on nurses’ sleep is well-studied, but there are other challenging aspects of health care work that might also affect the sleep of direct caregivers. This study examined the influence of the long-term care work environment on sleep quantity and quality of nursing assistants. A cross-sectional survey collected data from 650 nursing assistants in 15 long-term care facilities; 46% reported short sleep duration and 23% reported poor sleep quality. A simple additive index of the number of beneficial work features (up to 7) was constructed for analysis with Poisson regression. With each unit increase of beneficial work features, nursing assistants were 7% less likely to report short sleep duration and 17% less likely to report poor sleep quality. These results suggest that effective workplace interventions should address a variety of work stressors, not only work schedule arrangements, in order to improve nursing assistants’ sleep health. PMID:26384714

Sleep patterns of Japanese preschool children and their parents: implications for co-sleeping.

PubMed

Iwata, Sachiko; Iwata, Osuke; Matsuishi, Toyojiro

2013-06-01

The aim of this study was to investigate the direct relationship of sleep schedule and sleep quality variables between healthy preschool children and their parents, focusing on the influence of the difference in bedtime between each other. Forty-seven Japanese 5-year-old children and their primary parent were studied. The parents completed questionnaires including the Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index. The children wore an actigraph for one week. Although sleep patterns of children were generally independent of their parents, late sleep end time and bedtime of children were associated with parents' late sleep end time on weekends. For 87% of children and parents who shared a bedroom, sleep quality was negatively affected by a shorter difference in bedtimes between child and parent, but not by co-sleeping. Sleep behaviours of parents can influence those of their children. For parents and children who share a bedroom, the timing of bedtime rather than co-sleeping may be a key factor in modulating sleep patterns. Trying to get children asleep and subsequently falling asleep at a similar time may disturb parents' sleep quality, which may subsequently affect that of their children. ©2013 Foundation Acta Paediatrica. Published by Blackwell Publishing Ltd.

Morningness/eveningness and the need for sleep.

PubMed

Taillard, J; Philip, P; Bioulac, B

1999-12-01

The purpose of this study was to determine, in a large sample of adults of all ages (17-80 years), the effect of morningness/eveningness on sleep/wake schedules, sleep needs, sleep hygiene and subjective daytime somnolence. A total of 617 subjects (219 subjects per chronotype group) matched for age, sex and employment status, completed an abridged morningness/eveningness questionnaire, a questionnaire on sleep habits and the quality of sleep, and the Epworth Sleepiness Scale. Eveningness was associated with a greater need for sleep, less time in bed during the week compared to ideal sleep needs, more time in bed at the weekend, a later bedtime and waking-up time especially at the weekend, more irregular sleep/wake habits and greater caffeine consumption. These subjects built up a sleep debt during the week and extended their duration of sleep at the weekend. They did not, however, rate themselves more sleepy than other types, despite the fact that our results showed a clear link between subjectively evaluated daytime somnolence and sleep debt. Why they were less affected by sleep deprivation is not clear. This raises the question of individual susceptibility to the modification of sleep parameters.

International cooperative study of aircrew layover sleep Operational summary

NASA Technical Reports Server (NTRS)

Graeber, R. Curtis; Dement, William C.; Nicholson, Anthony N.; Sasaki, Mitsuo; Wegmann, Hans M.

1986-01-01

The findings of this cooperative study of layover sleep have direct implications for flight operations. In the consensus view of the principal investigators, these can be divided into their relevance for eastward or westward flight. Eastward flight produced more sleep disruption than westward. Different sleep and scheduling strategies are recommended for each flight direction, and the importance of individual crewmember factors is discussed in relation to age and circadian type. Despite the limitations of this study with regard to trip simplicity and the baseline data, the results for each airline are highly consistent and should be applicable to a wide range of long-haul crewmembers and carriers.

Managing neurobehavioral capability when social expediency trumps biological imperatives

PubMed Central

Spaeth, Andrea M.; Goel, Namni; Dinges, David F.

2013-01-01

Sleep, which is evolutionarily conserved across species, is a biological imperative that cannot be ignored or replaced. However, the percentage of habitually sleep-restricted adults has increased in recent decades. Extended work hours and commutes, shift work schedules, and television viewing are particularly potent social factors that influence sleep duration. Chronic partial sleep restriction, a product of these social expediencies, leads to the accumulation of sleep debt over time and consequently increases sleep propensity, decreases alertness, and impairs critical aspects of cognitive functioning. Significant interindividual variability in the neurobehavioral responses to sleep restriction exists—this variability is stable and phenotypic—suggesting a genetic basis. Identifying vulnerability to sleep loss is essential as many adults cannot accurately judge their level of impairment in response to sleep restriction. Indeed, the consequences of impaired performance and the lack of insight due to sleep loss can be catastrophic. In order to cope with the effects of social expediencies on biological imperatives, identification of biological (including genetic) and behavioral markers of sleep loss vulnerability as well as development of technological approaches for fatigue management are critical. PMID:22877676

Nocturnal sleep and daytime alertness of aircrew after transmeridian flights

NASA Technical Reports Server (NTRS)

Nicholson, Anthony N.; Pascoe, Peta A.; Spencer, Michael B.; Stone, Barbara M.; Green, Roger L.

1986-01-01

The nocturnal sleep and daytime alertness of aircrew were studied by electroencephalography and the multiple sleep latency test. After a transmeridian flight from London To San Francisco, sleep onset was faster and, although there was increased wakefulness during the second half of the night, sleep duration and efficiency over the whole night were not changed. The progressive decrease in sleep latencies observed normally in the multiple sleep latency test during the morning continued throughout the day after arrival. Of the 13 subjects, 12 took a nap of around 1-h duration in the afternoon preceding the return flight. These naps would have been encouraged by the drowsiness at this time and facilitated by the departure of the aircraft being scheduled during the early evening. An early evening departure had the further advantage that the circadian increase in vigilance expected during the early part of the day would occur during the latter part of the return flight.

Shift Work and Sleep Quality Among Urban Police Officers

PubMed Central

Fekedulegn, Desta; Burchfiel, Cecil M.; Charles, Luenda E.; Hartley, Tara A.; Andrew, Michael E.; Violanti, John M.

2016-01-01

Objective The aim of the study was to examine association of shift work with sleep quality in police officers. Methods Data were obtained from the Buffalo Cardio-Metabolic Occupational Police Stress study (n =363). An electronic work history database was used to define shift as day, afternoon, or night for three durations: past month, 1 year, and 15 years. Sleep quality was determined using the Pittsburgh Sleep Quality Index. Results The overall prevalence of poor sleep quality was 54%; 44% for day, 60% for afternoon, and 69% for night shift. Poor sleep quality was 70% more prevalent among night-shift officers (P <0.001) and 49% higher among those on the afternoon shift (P =0.003) relative to officers working on the day shift. Conclusions Night and evening work schedules are associated with elevated prevalence of poor sleep quality among police officers. PMID:26949891

Shift Work and Sleep Quality Among Urban Police Officers: The BCOPS Study.

PubMed

Fekedulegn, Desta; Burchfiel, Cecil M; Charles, Luenda E; Hartley, Tara A; Andrew, Michael E; Violanti, John M

2016-03-01

The aim of the study was to examine association of shift work with sleep quality in police officers. Data were obtained from the Buffalo Cardio-Metabolic Occupational Police Stress study (n = 363). An electronic work history database was used to define shift as day, afternoon, or night for three durations: past month, 1 year, and 15 years. Sleep quality was determined using the Pittsburgh Sleep Quality Index. The overall prevalence of poor sleep quality was 54%; 44% for day, 60% for afternoon, and 69% for night shift. Poor sleep quality was 70% more prevalent among night-shift officers (P < 0.001) and 49% higher among those on the afternoon shift (P = 0.003) relative to officers working on the day shift. Night and evening work schedules are associated with elevated prevalence of poor sleep quality among police officers.

Academy Helps Army Be All that It Can Be.

ERIC Educational Resources Information Center

Holden, Constance

1987-01-01

Summarizes a report which attempted to determine the usefulness of various human potential technologies in military training programs. Includes information on sleep learning, accelerated learning, mental practice, biofeedback, group cohesion, split-brain effects, altered mental states, influence strategies, and parapsychology. (TW)

Impaired driving performance in shiftworkers: the role of the circadian system in a multifactorial model

NASA Technical Reports Server (NTRS)

Richardson, G. S.; Miner, J. D.; Czeisler, C. A.

1989-01-01

A substantial and growing percentage of the U.S. work force now works on a rotating shift schedule. The repeated changes in sleep-wake, meal and work times inherent in such schedules conflict with the dictates of the internal biological clock and have adverse consequences for the health of the shiftworker population. An important consequence of this conflict is impaired performance, both on and off the job, as indexed by the increased incidence of motor vehicle accidents in shift workers. In this paper we report the results of a survey administered to rotating shift and straight day workers at a manufacturing plant in the eastern U.S. This survey documents an increased incidence of motor vehicle accidents or "near misses" in which sleepiness was implicated as a cause by the respondent. Complaints of poor sleep and increased sleepiness were also significantly more common in shiftworkers than day workers. Last, shiftworkers reported higher caffeine and alcohol consumption, and were more likely to use alcohol as a sleep aid. Although causal links cannot be established using these associative observations alone, previously reported experience with alteration of shift schedules, improvement of levels of alertness, and reduction in adverse performance outcomes corroborate the possibility of a causal link and suggest potential interventions.

[Relationship between Working Schedule and Sleeping Hours with Overweight and Obesity in Spanish Adult Population According to Data from the National Health Survey 2012].

PubMed

Marqueta de Salas, María; Rodríguez Gómez, Lorena; Enjuto Martínez, Diego; Juárez Soto, José Juan; Martín-Ramiro, José Javier

2017-03-01

Obesity is a public health problem worldwide. The aim of the present study was to determine the association between the type of working schedule and the sleeping hours per day with obesity and overweight. Cross-sectional study of the National Health Survey in 2012. We conducted an analysis of multinomial logistic regression and estimated the rates of possible risk of obesity and overweight versus the normal weight in relation to the type of working schedule and sleeping hours. Obesity among those who worked at night was 17,50% and those who had irregular works was 17,92%. Overweight among those who performed part-time works was 40,81% and 39,17% in night works. The obesity and overweight among those who slept less than six hours a day were 24,42% and 40,99% respectively. Regression analysis logistic showed OR=1,83 (IC95% 1,15-1,75) in irregular works and OR= 1,83 (IC95% 1,59-2,11) in people who slept less than six hours. Whenever overweight and obesity are present, a positive association between irregular jobs and short patterns of rest has been found, but stadistical significance is lost when estimating the OR adjusting the confounding factors.

Adaptation to shift work: physiologically based modeling of the effects of lighting and shifts' start time.

PubMed

Postnova, Svetlana; Robinson, Peter A; Postnov, Dmitry D

2013-01-01

Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers' sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers' adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21:00 instead of 00:00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters.

Adaptation to Shift Work: Physiologically Based Modeling of the Effects of Lighting and Shifts’ Start Time

PubMed Central

Postnova, Svetlana; Robinson, Peter A.; Postnov, Dmitry D.

2013-01-01

Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers’ sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers’ adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21∶00 instead of 00∶00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters. PMID:23308206

Validity and reliability of sleep time questionnaires in children and adolescents: A systematic review and meta-analysis.

PubMed

Nascimento-Ferreira, Marcus V; Collese, Tatiana S; de Moraes, Augusto César F; Rendo-Urteaga, Tara; Moreno, Luis A; Carvalho, Heráclito B

2016-12-01

Sleep duration has been associated with several health outcomes in children and adolescents. As an extensive number of questionnaires are currently used to investigate sleep schedule or sleep time, we performed a systematic review of criterion validation of sleep time questionnaires for children and adolescents, considering accelerometers as the reference method. We found a strong correlation between questionnaires and accelerometers for weeknights and a moderate correlation for weekend nights. When considering only studies performing a reliability assessment of the used questionnaires, a significant increase in the correlations for both weeknights and weekend nights was observed. In conclusion, moderate to strong criterion validity of sleep time questionnaires was observed; however, the reliability assessment of the questionnaires showed strong validation performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

Change from an 8-hour shift to a 12-hour shift, attitudes, sleep, sleepiness and performance.

PubMed

Lowden, A; Kecklund, G; Axelsson, J; Akerstedt, T

1998-01-01

The present study sought to evaluate the effect of a change from a rotating 3-shift (8-hour) to a 2-shift shift (12 hour) schedule on sleep, sleepiness, performance, perceived health, and well-being. Thirty-two shift workers at a chemical plant (control room operators) responded to a questionnaire a few months before a change was made in their shift schedule and 10 months after the change. Fourteen workers also filled out a diary, carried activity loggers, and carried out reaction-time tests (beginning and end of shift). Fourteen day workers served as a reference group for the questionnaires and 9 were intensively studied during a week with workdays and a free weekend. The questionnaire data showed that the shift change increased satisfaction with workhours, sleep, and time for social activities. Health, perceived accident risk, and reaction-time performance were not negatively affected. Alertness improved and subjective recovery time after night work decreased. The quick changes in the 8-hour schedule greatly increased sleep problems and fatigue. Sleepiness integrated across the entire shift cycle showed that the shift workers were less alert than the day workers, across workdays and days off (although alertness increased with the 12-hour shift). The change from 8-hour to 12-hour shifts was positive in most respects, possibly due to the shorter sequences of the workdays, the longer sequences of consecutive days off, the fewer types of shifts (easier planning), and the elimination of quick changes. The results may differ in groups with a higher work load.

Later endogenous circadian temperature nadir relative to an earlier wake time in older people

NASA Technical Reports Server (NTRS)

Duffy, J. F.; Dijk, D. J.; Klerman, E. B.; Czeisler, C. A.

1998-01-01

The contribution of the circadian timing system to the age-related advance of sleep-wake timing was investigated in two experiments. In a constant routine protocol, we found that the average wake time and endogenous circadian phase of 44 older subjects were earlier than that of 101 young men. However, the earlier circadian phase of the older subjects actually occurred later relative to their habitual wake time than it did in young men. These results indicate that an age-related advance of circadian phase cannot fully account for the high prevalence of early morning awakening in healthy older people. In a second study, 13 older subjects and 10 young men were scheduled to a 28-h day, such that they were scheduled to sleep at many circadian phases. Self-reported awakening from scheduled sleep episodes and cognitive throughput during the second half of the wake episode varied markedly as a function of circadian phase in both groups. The rising phase of both rhythms was advanced in the older subjects, suggesting an age-related change in the circadian regulation of sleep-wake propensity. We hypothesize that under entrained conditions, these age-related changes in the relationship between circadian phase and wake time are likely associated with self-selected light exposure at an earlier circadian phase. This earlier exposure to light could account for the earlier clock hour to which the endogenous circadian pacemaker is entrained in older people and thereby further increase their propensity to awaken at an even earlier time.

Daylight Saving Time Transitions and Road Traffic Accidents

PubMed Central

Lahti, Tuuli; Nysten, Esa; Haukka, Jari; Sulander, Pekka; Partonen, Timo

2010-01-01

Circadian rhythm disruptions may have harmful impacts on health. Circadian rhythm disruptions caused by jet lag compromise the quality and amount of sleep and may lead to a variety of symptoms such as fatigue, headache, and loss of attention and alertness. Even a minor change in time schedule may cause considerable stress for the body. Transitions into and out of daylight saving time alter the social and environmental timing twice a year. According to earlier studies, this change in time-schedule leads to sleep disruption and fragmentation of the circadian rhythm. Since sleep deprivation decreases motivation, attention, and alertness, transitions into and out of daylight saving time may increase the amount of accidents during the following days after the transition. We studied the amount of road traffic accidents one week before and one week after transitions into and out of daylight saving time during years from 1981 to 2006. Our results demonstrated that transitions into and out of daylight saving time did not increase the number of traffic road accidents. PMID:20652036

[Degree of sedation. Incidence of vomiting and time of postoperative sleep with 3 different oral administration schedules of hydroxyzine chlorhydrate and chloral hydrate].

PubMed

Díaz-Barriga, M G; Jackson-Herrerías, G

1990-01-01

In this paper a comparison of sedation effectiveness, vomiting incidence and postoperative sleeping time with three sedation schemes: Chloral hydrate exclusively, hidroxicine chlorhydrate the night before and 15 minutes before chloral hydrate administration and hidroxicine chlorhydrate 15 minutes before chloral hydrate. We find that there is no significant differences between these three sedation schemes in sedation, degree of postoperative sleeping time and vomiting incidence, therefore we can expect an effective sedation degree using any of these sedation methods.

Rotating shift work, sleep, and accidents related to sleepiness in hospital nurses

NASA Technical Reports Server (NTRS)

Gold, D. R.; Rogacz, S.; Bock, N.; Tosteson, T. D.; Baum, T. M.; Speizer, F. E.; Czeisler, C. A.

1992-01-01

A hospital-based survey on shift work, sleep, and accidents was carried out among 635 Massachusetts nurses. In comparison to nurses who worked only day/evening shifts, rotators had more sleep/wake cycle disruption and nodded off more at work. Rotators had twice the odds of nodding off while driving to or from work and twice the odds of a reported accident or error related to sleepiness. Application of circadian principles to the design of hospital work schedules may result in improved health and safety for nurses and patients.

Shift work and sleep disorder among textile mill workers in Bahir Dar, northwest Ethiopia.

PubMed

Abebe, Y; Fantahun, M

1999-07-01

To assess the length and quality of sleep among shift workers at Bahir Dar textile mill. A cross sectional study using structured questionnaire that contained sociodemographic variables, duration of work, work schedule, number of sleeping hours, sleep disorders, and associated reasons for such disorders. A textile mill in Bahir Dar, northwest Ethiopia. Three-hundred ninety four random sample of production workers of the mill. Sleep disorders, and the impact of external and home environment on sleep. The mean duration of work in the factory was 25.4 +/- 7.1 years. Ninety-seven per cent of the study population work in a rotating eight hourly shift system. The mean number of hours a worker sleeps after a worked shift was 5.1 +/- 2.3. Two hundred thirty (58.4%) claimed to experience a sleep disorder. Sleep disturbance was significantly associated with rotating shift work, external environmental noise, and working in the spinning department. The majority of the workers in Bahir Dar textile mill experienced sleep disturbances as detailed in the study methodology.

TV exposure associated with sleep disturbances in 5- to 6-year-old children.

PubMed

Paavonen, E Juulia; Pennonen, Marjo; Roine, Mira; Valkonen, Satu; Lahikainen, Anja Riitta

2006-06-01

The aim of this study was to investigate the effects of various forms of TV exposure on the quality of children's sleep. In this randomized population-based survey questionnaires concerning TV viewing, sleep disturbances, and psychiatric symptoms were administered to 321 parents of children aged 5-6 years. Sleep disturbance scores were the main outcome measures. Active TV viewing and passive TV exposure were related to sleeping difficulties, especially sleep-wake transition disorders and overall sleep disturbances. Particularly, passive TV exposure and viewing adult-targeted TV programs were strongly related to sleep disturbances. The association remained significant when socioeconomic status, family income, family conflicts, the father's work schedule, and the child's psychiatric symptoms were controlled statistically. The adjusted odds ratios were 2.91 (95% CI 1.03-8.17) and 3.01 (95% CI 1.13-8.05), respectively. TV viewing and particularly passive TV exposure and viewing adult-targeted programs significantly increase the risk of sleeping difficulties. The results suggest that health-care professionals should be aware of the association between TV exposure and sleep disturbances.

Effects of the new Accreditation Council for Graduate Medical Education work hour rules on surgical interns: a prospective study in a community teaching hospital.

PubMed

Kamine, Tovy Haber; Barron, Rebecca J; Lesicka, Agnieszka; Galbraith, John D; Millham, Frederick H; Larson, Janet

2013-02-01

On July 1, 2011, the Accreditation Council for Graduate Medical Education (ACGME) eliminated 30-hour call in an attempt to improve resident wakefulness. We surveyed interns on the Newton Wellesley Hospital (NWH) surgery service before and after the transition from Q4 overnight call to a night float schedule. For 15 weeks, interns completed weekly surveys including the Epworth Sleepiness Scale (ESS). The service changed to a night float schedule after 3 weeks (ie, first to 3-4 and then to 6 nights in a row). The average ESS score rose from 9.8 ± 5.2 to 14.9 ± 3.1 and 14.4 ± 4.5 (P = .042) on the 3/4 and 6/1 schedules, respectively. Interns were more likely to be abnormally tired on either night float schedule (relative risk = 2.86; 95% confidence interval, 1.17-6.97, P = .029). The new ACGME work hours increased the ESS scores among interns at NWH and caused interns to be more tired than interns on the Q4 schedule. This is likely caused by the multiple nights of poor sleep without a post-call day to make up sleep. Copyright © 2013 Elsevier Inc. All rights reserved.

The impact of junior doctors' worktime arrangements on their fatigue and well-being.

PubMed

Tucker, Philip; Brown, Menna; Dahlgren, Anna; Davies, Gwyneth; Ebden, Philip; Folkard, Simon; Hutchings, Hayley; Akerstedt, Torbjörn

2010-11-01

Many doctors report working excessively demanding schedules that comply with the European Working Time Directive (EWTD). We compared groups of junior doctors working on different schedules in order to identify which features of schedule design most negatively affected their fatigue and well-being in recent weeks. Completed by 336 doctors, the questionnaires focused on the respondents' personal circumstances, work situation, work schedules, sleep, and perceptions of fatigue, work-life balance and psychological strain. Working 7 consecutive nights was associated with greater accumulated fatigue and greater work-life interference, compared with working just 3 or 4 nights. Having only 1 rest day after working nights was associated with increased fatigue. Working a weekend on-call between 2 consecutive working weeks was associated with increased work-life interference. Working frequent on-calls (either on weekends or during the week) was associated with increased work-life interference and psychological strain. Inter-shift intervals of <10 hours were associated with shorter periods of sleep and increased fatigue. The number of hours worked per week was positively associated with work-life interference and fatigue on night shifts. The current findings identify parameters, in addition to those specified in the EWTD, for designing schedules that limit their impact on doctors' fatigue and well-being.

Screening Commercial Vehicle Drivers for Obstructive Sleep Apnea: Tools, Barriers, and Recommendations.

PubMed

Evans, Kelly A; Yap, Tracey; Turner, Barbara

2017-10-01

Obstructive sleep apnea (OSA) is a disorder characterized by a cessation of breathing during sleep, leading to poor sleep patterns and daytime somnolence. Daytime somnolence is of particular concern for commercial vehicle drivers, whose crash risk increases 50% with untreated OSA. The process of diagnosing and treating OSA in commercial drivers begins with effective and consistent screening. Therefore, the researchers screened drivers with both the STOP-Bang Questionnaire and the Obstructive Sleep Apnea Evaluation Worksheet (OSAEW) and compared the two tools. Drivers screening positive on the STOP-Bang Questionnaire, OSAEW, and both questionnaires were 28%, 23%, and 13%, respectively. Sleep study referrals were made for 50 drivers; 12 drivers were scheduled for sleep tests within 3 months. Health care provider referral rates for drivers screening at high risk (37%) and commercial driver monitoring rates (24%) were both low. Recommendations to improve OSA screening and testing practices include Federal Motor Carrier Safety Administration-mandated screening and referral guidelines, employee-facilitated sleep testing, and OSA awareness campaigns.

A Rodent Model of Night-Shift Work Induces Short-Term and Enduring Sleep and Electroencephalographic Disturbances.

PubMed

Grønli, Janne; Meerlo, Peter; Pedersen, Torhild T; Pallesen, Ståle; Skrede, Silje; Marti, Andrea R; Wisor, Jonathan P; Murison, Robert; Henriksen, Tone E G; Rempe, Michael J; Mrdalj, Jelena

2017-02-01

Millions of people worldwide are working at times that overlap with the normal time for sleep. Sleep problems related to the work schedule may mediate the well-established relationship between shift work and increased risk for disease, occupational errors and accidents. Yet, our understanding of causality and the underlying mechanisms that explain this relationship is limited. We aimed to assess the consequences of night-shift work for sleep and to examine whether night-shift work-induced sleep disturbances may yield electrophysiological markers of impaired maintenance of the waking brain state. An experimental model developed in rats simulated a 4-day protocol of night-work in humans. Two groups of rats underwent 8-h sessions of enforced ambulation, either at the circadian time when the animal was physiologically primed for wakefulness (active-workers, mimicking day-shift) or for sleep (rest-workers, mimicking night-shift). The 4-day rest-work schedule induced a pronounced redistribution of sleep to the endogenous active phase. Rest-work also led to higher electroencephalogram (EEG) slow-wave (1-4 Hz) energy in quiet wakefulness during work-sessions, suggesting a degraded waking state. After the daily work-sessions, being in their endogenous active phase, rest-workers slept less and had higher gamma (80-90 Hz) activity during wake than active-workers. Finally, rest-work induced an enduring shift in the main sleep period and attenuated the accumulation of slow-wave energy during NREM sleep. A comparison of recovery data from 12:12 LD and constant dark conditions suggests that reduced time in NREM sleep throughout the recorded 7-day recovery phase induced by rest-work may be modulated by circadian factors. Our data in rats show that enforced night-work-like activity during the normal resting phase has pronounced acute and persistent effects on sleep and waking behavior. The study also underscores the potential importance of animal models for future studies on the health consequences of night-shift work and the mechanisms underlying increased risk for diseases.

Effects of Nighttime Light Radiance on the Sleep of the General Population

NASA Technical Reports Server (NTRS)

Ohayon, Maurice M.; Milesi, Cristina

2015-01-01

The objectives of this study is to verify if the exposure to greater nighttime radiance is associated with changes in the sleep/wake schedule and with greater sleep disturbances. Methods: The target population was the adults (18 years and older) living in California, USA. This represents 24 million of inhabitants. A total of 3,104 subjects participated in the survey (participation rate 85.6%). The participants were interviewed by telephone using the Sleep-EVAL system. The interviews covered several topics including sleeping habits, sleep quality, sleep disturbances, physical symptoms related to menopause. Chronic insomnia was defined as difficulty initiating or maintaining sleep for at least 3 months. Global nighttime light emissions have been collected by the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS) sensors. We extracted the radiance calibrated nighttime lights corresponding to the date of the interviews for a three by three window centered on each coordinate corresponding to an interview address. Results: Dissatisfaction with sleep quantity and/or quality was associated with an increased nighttime radiance (p=0.02). Similarly, excessive sleepiness accompanied with impaired functioning was significantly associated with an increased nighttime radiance (p (is) less than 0.0001). The association remained significant after controlling for age, gender and use of a night lamp in the bedroom. Confusional arousals were also significantly associated with an increased nighttime radiance (p (is) less than 0.0001). Bedtime hour was linearly increasing with the intensity of nighttime radiance: the later the bedtime, the greater the nighttime radiance (p (is) less than 0.0001). Similarly, wakeup time became progressively later as the nighttime radiance increased (p (is) less than 0.0001). Both associations remained significant after controlling for age, gender and use of a night lamp in the bedroom. Circadian Rhythm Disorders were the only sleep disorder significantly associated with increased nighttime radiance (p (is) less than 0.0001). Exposure to increased nighttime light radiance appeared to cause a shift in the sleep/wake schedule, excessive sleepiness and Circadian Rhythm Disorders.

Shift work disorder, depression, and anxiety in the transition to rotating shifts: the role of sleep reactivity.

PubMed

Kalmbach, David A; Pillai, Vivek; Cheng, Philip; Arnedt, J Todd; Drake, Christopher L

2015-12-01

The aim of this study is to investigate premorbid sleep reactivity as a vulnerability to incident shift work disorder (SWD), and related changes in depression as well as anxiety following a transition to a rotating shifts work schedule. This is a longitudinal study with two waves of data collection. The community-based sample included normal sleeping non-shift workers (N = 96; 62.5% female; 47.9 ± 13.3 years) without a lifetime history of insomnia or baseline excessive daytime sleepiness who transitioned to rotating shift work one year later. Participants reported demographic characteristics, trait sleep reactivity on the Ford Insomnia Response to Stress Test, depression symptoms on the Quick Inventory of Depression Symptomatology, and anxiety symptoms on the Beck Anxiety Inventory. SWD was determined based on significant sleep disturbance and/or excessive sleepiness in the context of working in a rotating-shift schedule. Analyses revealed that the odds were over five times greater for highly sleep-reactive individuals to develop SWD after transitioning to rotating shifts (OR = 5.59, p = 0.04). Nearly 90% of participants who suffered from SWD were accurately identified as high risk at one year before disease onset. Furthermore, individuals who developed SWD reported greater increases in symptoms of depression and anxiety. Finally, analyses revealed significant indirect effects wherein high sleep reactivity increased risk for SWD, which led to greater severity of anxiety and depression symptoms. The Ford Insomnia Response to Stress Test (FIRST) accurately identifies a focused target population in which the premorbid psychobiological processes complicit in SWD onset and progression, as well as shift work-related depression and anxiety changes, can be better investigated, thus improving future preventative efforts. Copyright © 2015 Elsevier B.V. All rights reserved.

Shift Work Disorder, Depression, and Anxiety in the Transition to Rotating Shifts: The Role of Sleep Reactivity

PubMed Central

Kalmbach, David A; Pillai, Vivek; Cheng, Philip; Arnedt, J Todd; Drake, Christopher L

2016-01-01

Objectives To investigate premorbid sleep reactivity as a vulnerability to incident shift work disorder and related changes in depression and anxiety following a transition to a rotating shifts work schedule. Methods This is a longitudinal study with two waves of data collection. The community-based sample included normal sleeping non-shift workers (N=96; 62.5% female; 47.9±13.3 yo) without a lifetime history of insomnia or baseline excessive daytime sleepiness who transitioned to rotating shift work one year later. Participants reported demographic characteristics, trait sleep reactivity on the Ford Insomnia Response to Stress Test, depression symptoms on the Quick Inventory of Depression Symptomatology, and anxiety symptoms on the Beck Anxiety Inventory. Shift work disorder was determined based on significant sleep disturbance and/or excessive sleepiness in the context of working a rotating shifts schedule. Results Analyses revealed that the odds were over five times greater for highly sleep reactive individuals to develop shift work disorder after transitioning to rotating shifts (OR=5.59, p=.04). Nearly 90% of shift work disorder sufferers were accurately identified as high risk at 1-y prior to disease onset. Furthermore, individuals who developed SWD reported greater increases in symptoms of depression and anxiety. Finally, analyses revealed significant indirect effects wherein high sleep reactivity increased risk for SWD, which led to greater severity of anxiety and depression symptoms. Conclusions The FIRST accurately identifies a focused target population in which the premorbid psychobiological processes complicit in SWD onset and progression, as well as shift work-related depression and anxiety changes, can be better investigated, thus improving future preventative efforts. PMID:26611952

Fatigue on the flight deck: the consequences of sleep loss and the benefits of napping.

PubMed

Hartzler, Beth M

2014-01-01

The detrimental effects of fatigue in aviation are well established, as evidenced by both the number of fatigue-related mishaps and numerous studies which have found that most pilots experience a deterioration in cognitive performance as well as increased stress during the course of a flight. Further, due to the nature of the average pilot's work schedule, with frequent changes in duty schedule, early morning starts, and extended duty periods, fatigue may be impossible to avoid. Thus, it is critical that fatigue countermeasures be available which can help to combat the often overwhelming effects of sleep loss or sleep disruption. While stimulants such as caffeine are typically effective at maintaining alertness and performance, such countermeasures do nothing to address the actual source of fatigue - insufficient sleep. Consequently, strategic naps are considered an efficacious means of maintaining performance while also reducing the individual's sleep debt. These types of naps have been advocated for pilots in particular, as opportunities to sleep either in the designated rest facilities or on the flight deck may be beneficial in reducing both the performance and alertness impairments associated with fatigue, as well as the subjective feelings of sleepiness. Evidence suggests that strategic naps can reduce subjective feelings of fatigue and improve performance and alertness. Despite some contraindications to implementing strategic naps while on duty, such as sleep inertia experienced upon awakening, both researchers and pilots agree that the benefits associated with these naps far outweigh the potential risks. This article is a literature review detailing both the health and safety concerns of fatigue among commercial pilots as well as benefits and risks associated with strategic napping to alleviate this fatigue. Published by Elsevier Ltd.

Sleep and Athletic Performance.

PubMed

Watson, Andrew M

Sleep is an essential component of health and well-being, with significant impacts on physical development, emotional regulation, cognitive performance, and quality of life. Along with being an integral part of the recovery and adaptive process between bouts of exercise, accumulating evidence suggests that increased sleep duration and improved sleep quality in athletes are associated with improved performance and competitive success. In addition, better sleep may reduce the risk of both injury and illness in athletes, not only optimizing health but also potentially enhancing performance through increased participation in training. Despite this, most studies have found that athletes fail to obtain the recommended amount of sleep, threatening both performance and health. Athletes face a number of obstacles that can reduce the likelihood of obtaining proper sleep, such as training and competition schedules, travel, stress, academic demands, and overtraining. In addition, athletes have been found to demonstrate poor self-assessment of their sleep duration and quality. In light of this, athletes may require more careful monitoring and intervention to identify individuals at risk and promote proper sleep to improve both performance and overall health. This review attempts to highlight the recent literature regarding sleep issues in athletes, the effects of sleep on athletic performance, and interventions to enhance proper sleep in athletes.

Sleep and youth suicidal behavior: a neglected field.

PubMed

Liu, Xianchen; Buysse, Daniel J

2006-05-01

Sleep undergoes substantial changes during adolescence and suicide risk begins to increase during this period as well. This review focuses on recent literature on the relationship between sleep and suicidal behavior and proposes directions for future research. Adolescent sleep is characterized by widespread sleep restriction, irregular sleep schedules, daytime sleepiness, and elevated risk for sleep disturbances. More research on adolescent sleep and psychosocial impairment, psychiatric disorders, and suicidal behavior has been conducted. Suicidal psychiatric patients had more sleep disturbances including insomnia, hypersomnia, or nightmares than nonsuicidal patients. Shorter rapid eye movement latency and increased rapid eye movement activity have been noted to be a marker of suicidality in psychiatric patients. Epidemiological studies have demonstrated that insomnia, nightmares, and sleep insufficiency are associated with elevated risk for suicide. Although the link between insomnia and suicidal behavior appears to be mediated by depression, existing data suggest an independent predictive role of nightmares in future suicidal behavior. Sleep loss or disturbances are likely to signal an increased risk of future suicidal action in adolescents. Large-scale prospective studies and neurobiological studies are needed for a better understanding of the complex relationship between sleep, psychopathology, and youth suicidal behavior.

Parental Concerns About Infant and Toddler Sleep Assessed by a Mobile App.

PubMed

Mindell, Jodi A; Leichman, Erin S; Puzino, Kristina; Walters, Russel; Bhullar, Bula

2015-01-01

The aim of this study was to assess the primary concerns of parents/caregivers regarding their young child's sleep. A total of 1,287 consecutive sleep-related questions were analyzed from submissions to an Ask the Expert section of a publicly available iPhone-based application for sleep in young children. Questions regarding infants were most likely to be submitted (53.9%), followed by newborns (23.76%) and toddlers (17.8%), with an average age of 10.94 months. The primary concerns regarded night wakings, sleep schedules, and bedtime problems, accounting for almost 85% of all questions. Results align with common concerns noted in epidemiological studies. Understanding the types of concerns for which parents seek advice is beneficial in the continued development of resources for caregivers.

Sleep quality and high intensity interval training at two different times of day: A crossover study on the influence of the chronotype in male collegiate soccer players.

PubMed

Vitale, Jacopo A; Bonato, Matteo; Galasso, Letizia; La Torre, Antonio; Merati, Giampiero; Montaruli, Angela; Roveda, Eliana; Carandente, Franca

2017-01-01

The influence of the chronotype on the sleep quality in male collegiate soccer players in response to acute high intensity interval training (HIIT) performed at two different times of day was evaluated. The sleep quality was poorer in the morning-type than in the evening-type players after the evening HIIT session, whereas no significant changes in the sleep quality of the two chronotypes after the morning HIIT session was observed. The results suggest that an athlete's chronotype should be taken into account when scheduling training sessions and to promote faster recovery processes.

Trials of bright light exposure and melatonin administration in a patient with non-24 hour sleep-wake syndrome.

PubMed

Hayakawa, T; Kamei, Y; Urata, J; Shibui, K; Ozaki, S; Uchiyama, M; Okawa, M

1998-04-01

We report a patient with non-24 h sleep-wake syndrome (non-24) whose free-running sleep-wake cycle was successfully treated with both scheduled bright light exposure and melatonin treatment. In the present study, morning bright light as well as evening melatonin phase-advanced sleep-wake cycles and melatonin rhythm. Both these procedures achieved appropriate entrainment to a 24 h day. However, the patient did not continue morning bright light therapy after the discharge. Rising at appropriate times in the morning for bright light therapy was difficult for him to continue. Melatonin treatment was better tolerated because of its ease of application.

Do respiratory cycle-related EEG changes or arousals from sleep predict neurobehavioral deficits and response to adenotonsillectomy in children?

PubMed

Chervin, Ronald D; Garetz, Susan L; Ruzicka, Deborah L; Hodges, Elise K; Giordani, Bruno J; Dillon, James E; Felt, Barbara T; Hoban, Timothy F; Guire, Kenneth E; O'Brien, Louise M; Burns, Joseph W

2014-08-15

Pediatric obstructive sleep apnea (OSA) is associated with hyperactive behavior, cognitive deficits, psychiatric morbidity, and sleepiness, but objective polysomnographic measures of OSA presence or severity among children scheduled for adenotonsillectomy have not explained why. To assess whether sleep fragmentation might explain neurobehavioral outcomes, we prospectively assessed the predictive value of standard arousals and also respiratory cycle-related EEG changes (RCREC), thought to reflect inspiratory microarousals. Washtenaw County Adenotonsillectomy Cohort II participants included children (ages 3-12 years) scheduled for adenotonsillectomy, for any clinical indication. At enrollment and again 7.2 ± 0.9 (SD) months later, children had polysomnography, a multiple sleep latency test, parent-completed behavioral rating scales, cognitive testing, and psychiatric evaluation. The RCREC were computed as previously described for delta, theta, alpha, sigma, and beta EEG frequency bands. Participants included 133 children, 109 with OSA (apnea-hypopnea index [AHI] ≥ 1.5, mean 8.3 ± 10.6) and 24 without OSA (AHI 0.9 ± 0.3). At baseline, the arousal index and RCREC showed no consistent, significant associations with neurobehavioral morbidities, among all subjects or the 109 with OSA. At follow-up, the arousal index, RCREC, and neurobehavioral measures all tended to improve, but neither baseline measure of sleep fragmentation effectively predicted outcomes (all p > 0.05, with only scattered exceptions, among all subjects or those with OSA). Sleep fragmentation, as reflected by standard arousals or by RCREC, appears unlikely to explain neurobehavioral morbidity among children who undergo adenotonsillectomy. ClinicalTrials.gov, ID: NCT00233194.

Sleep timing is associated with diet and physical activity levels in 9-11-year-old children from Dunedin, New Zealand: the PEDALS study.

PubMed

Harrex, Harriet A L; Skeaff, Sheila A; Black, Katherine E; Davison, Brittany K; Haszard, Jillian J; Meredith-Jones, Kim; Quigg, Robin; Saeedi, Pouya; Stoner, Lee; Wong, Jyh E; Skidmore, Paula M L

2017-11-20

It is well documented that short sleep duration is associated with excess body weight and poor food intake in children. It has been suggested that sleep timing behaviour may also be an important predictor of weight and other related behaviours, independent of sleep duration; however, there is a lack of research investigating these relationships. The present study investigated sleep timing in association with diet and physical activity levels in 439 children aged 9-11 years old from New Zealand. Sleep and physical activity data were collected using accelerometry, and food choice using a short food-frequency questionnaire. Participants were classified into one of four sleep timing behaviour categories using the median split for sleep-onset and -offset times. Differences between sleep timing groups for weekly consumption frequency of selected food groups, dietary pattern scores and minutes of moderate-to-vigorous physical activity were examined. Children in the late sleep/late wake category had a lower 'Fruit & Vegetables' pattern score [mean difference (95% CI): -0.3 (-0.5, -0.1)], a lower consumption frequency of fruit and vegetables [mean weekly difference (95% CI): -2.9 (-4.9, -0.9)] and a higher consumption frequency of sweetened beverages [mean weekly difference (95% CI): 1.8 (0.2, 3.3)] compared with those in the early sleep/early wake category. Additionally, children in the late sleep/late wake category accumulated fewer minutes of moderate-to-vigorous physical activity per day compared with those in the early sleep/early wake category [mean difference (95% CI): -9.4 (-15.3, -3.5)]. These findings indicate that sleep timing, even after controlling for sleep duration, was associated with both food consumption and physical activity. © 2017 European Sleep Research Society.

Ventilatory control sensitivity in patients with obstructive sleep apnea is sleep stage dependent.

PubMed

Landry, Shane A; Andara, Christopher; Terrill, Philip I; Joosten, Simon A; Leong, Paul; Mann, Dwayne L; Sands, Scott A; Hamilton, Garun S; Edwards, Bradley A

2018-05-01

The severity of obstructive sleep apnea (OSA) is known to vary according to sleep stage; however, the pathophysiology responsible for this robust observation is incompletely understood. The objective of the present work was to examine how ventilatory control system sensitivity (i.e. loop gain) varies during sleep in patients with OSA. Loop gain was estimated using signals collected from standard diagnostic polysomnographic recordings performed in 44 patients with OSA. Loop gain measurements associated with nonrapid eye movement (NREM) stage 2 (N2), stage 3 (N3), and REM sleep were calculated and compared. The sleep period was also split into three equal duration tertiles to investigate how loop gain changes over the course of sleep. Loop gain was significantly lower (i.e. ventilatory control more stable) in REM (Mean ± SEM: 0.51 ± 0.04) compared with N2 sleep (0.63 ± 0.04; p = 0.001). Differences in loop gain between REM and N3 (p = 0.095), and N2 and N3 (p = 0.247) sleep were not significant. Furthermore, N2 loop gain was significantly lower in the first third (0.57 ± 0.03) of the sleep period compared with later second (0.64 ± 0.03, p = 0.012) and third (0.64 ± 0.03, p = 0.015) tertiles. REM loop gain also tended to increase across the night; however, this trend was not statistically significant [F(2, 12) = 3.49, p = 0.09]. These data suggest that loop gain varies between REM and NREM sleep and modestly increases over the course of sleep. Lower loop gain in REM is unlikely to contribute to the worsened OSA severity typically observed in REM sleep, but may explain the reduced propensity for central sleep apnea in this sleep stage.

Insomnia

MedlinePlus

... therapy are generally the best treatment for persistent insomnia. Sleeping on a regular schedule, exercising regularly, avoiding caffeine and daytime naps, and keeping stress in check also are likely to help. But ...

Shift Work and Sleep: Medical Implications and Management

PubMed Central

Jehan, Shazia; Zizi, Ferdinand; Pandi-Perumal, Seithikurippu R; Myers, Alyson K; Auguste, Evan; Jean-Louis, Girardin; McFarlane, Samy I

2018-01-01

The primary occupation of a worker can play an important role in achieving good sleep, as well as good physical and mental health. Shift Work Sleep Disorder (SWSD) is a condition that results from working atypical shifts (i.e. other than the typical 9 am to 5 pm schedule). Individuals who manifest SWSD usually complaint of trouble sleeping, excessive sleepiness and fatigue which interfere with overall functioning. Misalignment of circadian timing system results in undesirable health consequences. Among shift workers, good sleep is essential for efficient functioning. Disturbed sleep is associated with anxiety, depression, poor physical and mental health and eventually, leads to impaired quality of life. The economic burden of undiagnosed, under-and untreated shift work is high. The healthcare workers and policymakers can play a pivotal role in dealing with this issue by educating the public and providing them with adequate privileges to perform their work. PMID:29517053

Work-Family Conflict, Sleep, and Mental Health of Nursing Assistants Working in Nursing Homes.

PubMed

Zhang, Yuan; Punnett, Laura; Nannini, Angela

2017-07-01

Work-family conflict is challenging for workers and may lead to depression, anxiety, and overall poor health. Sleep plays an important role in the maintenance of mental health; however, the role of sleep in the association between work-family conflict and mental health is not well-studied. Questionnaires were collected from 650 nursing assistants in 15 nursing homes. Multivariate linear regression modeling demonstrated that increased work-family conflict was associated with lower mental health scores (β = -2.56, p < .01). More work-family conflict was correlated with more job demands, less job control, less social support, and longer work hours. Poor sleep quality, but not short sleep duration, mediated the association between work-family conflict and mental health. Workplace interventions to improve nursing assistants' mental health should increase their control over work schedules and responsibilities, provide support to meet their work and family needs, and address healthy sleep practices.

Reduced sleep duration and history of work-related injuries among Washington State adolescents with a history of working.

PubMed

Graves, Janessa M; Miller, Mary E

2015-04-01

The relationship between sleep and occupational injury risk has not been adequately explored for working adolescents. Data were analyzed from the 2010 Washington State Healthy Youth Survey of 8th, 10th, and 12th grade public school students. Teens reported average school and weekend night sleep hours and history of work-related injury that received medical treatment. Multivariable logistic regression evaluated the association between sleep duration and occupational injury. Of 4,144 working teens, 6.4% reported ever having an occupational injury. Teens who sleep ≤5 hr/school night had greater odds of a history of occupational injury than those sleeping 8 hr (OR:2.91, 95% CI:1.85-4.57). No significant association was observed for weekend night sleep duration. Reduced school night sleep was associated with increased odds of work-related injury in adolescents. Long hours and late night schedules may contribute to decreased sleep time and potentially have other health and developmental impacts for youth. © 2015 Wiley Periodicals, Inc.

Childhood obesity and sleep: relatives, partners, or both?--a critical perspective on the evidence.

PubMed

Gozal, David; Kheirandish-Gozal, Leila

2012-08-01

In modern life, children are unlikely to obtain sufficient or regular sleep and waking schedules. Inadequate sleep affects the regulation of homeostatic and hormonal systems underlying somatic growth, maturation, and bioenergetics. Therefore, assessments of the obesogenic lifestyle, including as dietary and physical activity, need to be coupled with accurate evaluation of sleep quality and quantity, and coexistence of sleep apnea. Inclusion of sleep as an integral component of research studies on childhood obesity should be done as part of the study planning process. Although parents and health professionals have quantified normal patterns of activities in children, sleep has been almost completely overlooked. As sleep duration in children appears to have declined, reciprocal obesity rates have increased. Also, increases in pediatric obesity rates have markedly increased the risk of obstructive sleep apnea syndrome (OSAS) in children. Obesity and OSAS share common pathways underlying end-organ morbidity, potentially leading to reciprocal amplificatory effects. The relative paucity of data on the topics covered in the perspective below should serve as a major incentive toward future research on these critically important concepts. © 2012 New York Academy of Sciences.

Association between sleep quality and nurse productivity among Korean clinical nurses.

PubMed

Park, Eunok; Lee, Hyo Young; Park, Claire Su-Yeon

2018-06-01

To determine the association between sleep quality and nurse productivity. Although poor sleep quality may decrease nurses' productivity, the association between the two has not yet been evaluated in the literature. A cross-sectional survey was completed in May 2014 by 188 nurses working in acute hospitals in South Korea using the Pittsburgh Sleep Quality Index. Descriptive statistics, t tests, ANOVA, Pearson's correlation, and stepwise multiple regression were conducted for data analysis. The prevalence of poor sleep quality was high (79.8%). Among the components of sleep quality, sleep disturbances (β = -0.19) and subjective sleep quality (β = -0.16) were determined to be statistically significant predictive factors of nurse productivity, in addition to shift work (β = -0.20) and age (β = 0.32). Poor sleep quality may lead to lower nurse productivity. Nurse leaders and executives should consider measures to improve nurses' sleep quality and enhance nurse productivity. Steps that need to be considered include longer intervals between shift-work cycles, clockwise scheduling order, a longer break time after night shift work, allowing nurses to nap before / during a night shift, and providing a worksite healthy sleep programme. © 2018 John Wiley & Sons Ltd.

[Sleep quality of nurses working in shifts - Hungarian adaptation of the Bergen Shift Work Sleep Questionnaire].

PubMed

Fusz, Katalin; Tóth, Ákos; Fullér, Noémi; Müller, Ágnes; Oláh, András

2015-12-06

Sleep disorders among shift workers are common problems due to the disturbed circadian rhythm. The Bergen Shift Work Sleep Questionnaire assesses discrete sleep problems related to work shifts (day, evening and night shifts) and rest days. The aim of the study was to develop the Hungarian version of this questionnaire and to compare the sleep quality of nurses in different work schedules. 326 nurses working in shifts filled in the questionnaire. The authors made convergent and discriminant validation of the questionnaire with the Athens Insomnia Scale and the Perceived Stress Questionnaire. The questionnaire based on psychometric characteristics was suitable to assess sleep disorders associated with shift work in a Hungarian sample. The frequency of discrete symptoms significantly (p<0.001) differed with the shifts. Nurses experienced the worst sleep quality and daytime fatigue after the night shift. Nurses working in irregular shift system had worse sleep quality than nurses working in regular and flexible shift system (p<0.001). The sleep disorder of nurses working in shifts should be assessed with the Hungarian version of the Bergen Shift Work Sleep Questionnaire on a nationally representative sample, and the least burdensome shift system could be established.

Frontal Underactivation During Working Memory Processing in Adults With Acute Partial Sleep Deprivation: A Near-Infrared Spectroscopy Study.

PubMed

Yeung, Michael K; Lee, Tsz L; Cheung, Winnie K; Chan, Agnes S

2018-01-01

Individuals with partial sleep deprivation may have working memory (WM) impairment, but the underlying neural mechanism of this phenomenon is relatively unknown. The present study examined neural processing during WM performance in individuals with and without partial sleep deprivation using near-infrared spectroscopy (NIRS). Forty college students (10 males) were equally split into Sufficient Sleep (SS) and Insufficient Sleep (IS) groups based on self-reports of previous night's sleep duration. Participants in the SS group obtained the recommended amounts of sleep according to various sleep organizations (i.e., >7.0 h), whereas those in the IS group obtained amounts of sleep no greater than the lower limit of the recommendation (i.e., ≤7.0 h). All participants underwent an n -back paradigm with a WM load (i.e., 3-back) and a control condition (i.e., 0-back) while their prefrontal hemodynamics were recorded by NIRS. The IS and SS groups performed the tasks comparably well. However, unlike the SS group, which exhibited bilateral frontal activation indicated by increased oxyhemoglobin concentration and decreased deoxyhemoglobin concentration during WM processing (i.e., 3-back > 0-back), the IS group did not exhibit such activation. In addition, levels of WM-related frontal activation, especially those on the left side, correlated with sleep duration the night before, even when habitual sleep duration was controlled for. The findings suggest the presence of frontal lobe dysfunction in the absence of evident WM difficulties in individuals with acute partial sleep deprivation. They also highlight the importance of a good night's sleep to brain health.

[Habits and problems of sleep in adolescent students].

PubMed

Lazaratou, E; Dikeos, D; Anagnostopoulos, D; Soldatos, C

2008-07-01

The evaluation of sleep habits and sleep related problems in high school adolescent students in the Athens area and the assessment of these problems' relation to demographic and other variables was investigated by the Athens Insomnia Scale - 5 item version (AIS-5), which was administered to 713 adolescent Senior High School students in the Greater Athens Area. Data such as age, sex, school records, and time spent per week in school-related and extracurricular activities were collected. The sample's mean sleep duration was 7,5 hours, mean bedtime 12:20 am and wake-up time 7:15 am. Total sleep time was not affected by gender, but was influenced by time spent in various activities. Sleep complaints were related to delayed sleep, onset latency and insufficient total duration of sleep. Girls complained more than boys, while correlations showed that students with lower academic per formance and those in second grade were more likely to have higher AIS-5 scores. The results show that sleep time of high school students is dependent on practical matters such as school schedule and other activities, while sleep complaints are related to female gender, bad school performance as well as to the second grade. The difference between actual sleep time and sleep complaints should be considered when studying the sleep of adolescents.

ABCs of SLEEPING: A review of the evidence behind pediatric sleep practice recommendations.

PubMed

Allen, Stephanie L; Howlett, Melissa D; Coulombe, J Aimée; Corkum, Penny V

2016-10-01

The ABCs of SLEEPING mnemonic was developed to serve as an organizing framework for common pediatric sleep recommendations. The mnemonic stands for 1) age appropriate bedtimes and wake-times with consistency, 2) schedules and routines, 3) location, 4) exercise and diet, 5) no electronics in the bedroom or before bed, 6) positivity 7) independence when falling asleep and 8) needs of child met during the day, 9) equal great sleep. This review examines the empirical evidence behind the practices and recommendations captured by the ABCs of SLEEPING mnemonic for children aged 1 to 12. A search was conducted of key electronic databases (PubMed, PsycINFO, CINAHL, & EMBASE) to identify English articles that included the concepts of sleep, insomnia, and/or bedtime. 77 articles were eligible for inclusion and were coded to extract key details and findings regarding the relations between sleep practices identified in the ABCs of SLEEPING mnemonic and sleep outcomes. Findings provided preliminary support for many of the recommendations that are commonly made to families regarding healthy sleep practices. However, more robust investigations are needed to better understand the causal contributions of healthy sleep practices to the onset and maintenance of children's sleep problems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sleep Hygiene and Sleep Quality of Third-Trimester Pregnant Women.

PubMed

Tsai, Shao-Yu; Lee, Chien-Nan; Wu, Wei-Wen; Landis, Carol A

2016-02-01

The purpose of this descriptive study was to examine the associations of sleep hygiene and actigraphy measures of sleep with self-reported sleep quality in 197 pregnant women in northern Taiwan. Third-trimester pregnant women completed the Sleep Hygiene Practice Scale (SHPS) and the Pittsburgh Sleep Quality Index (PSQI) as well as the Center for Epidemiologic Studies-Depression Scale (CES-D), and wore an actigraph for 7 consecutive days. Student's t-test was used to compare the SHPS scores and means as well as variability of actigraphy sleep variables between poor sleepers (i.e., PSQI global score >5) and good sleepers (i.e., PSQI global score ≤5). Compared to good sleepers, poor sleepers reported significantly worse sleep hygiene, with higher SHPS scores and higher sleep schedule, arousal-related behavior, and sleep environment subscale scores. Poor sleepers had significantly greater intra-individual variability of sleep onset latency, total nighttime sleep, and wake after sleep onset than good sleepers. In stepwise linear regression, older maternal age (p = .01), fewer employment hours per week (p = .01), higher CES-D total score (p < .01), and higher SHPS arousal-related behavior subscale scores (p < .01) predicted self-reported global sleep quality. Findings support avoiding physically, physiologically, emotionally, or cognitively arousing activities before bedtime as a target for sleep-hygiene intervention in women during pregnancy. © 2015 Wiley Periodicals, Inc.

Parallel Directionally Split Solver Based on Reformulation of Pipelined Thomas Algorithm

NASA Technical Reports Server (NTRS)

Povitsky, A.

1998-01-01

In this research an efficient parallel algorithm for 3-D directionally split problems is developed. The proposed algorithm is based on a reformulated version of the pipelined Thomas algorithm that starts the backward step computations immediately after the completion of the forward step computations for the first portion of lines This algorithm has data available for other computational tasks while processors are idle from the Thomas algorithm. The proposed 3-D directionally split solver is based on the static scheduling of processors where local and non-local, data-dependent and data-independent computations are scheduled while processors are idle. A theoretical model of parallelization efficiency is used to define optimal parameters of the algorithm, to show an asymptotic parallelization penalty and to obtain an optimal cover of a global domain with subdomains. It is shown by computational experiments and by the theoretical model that the proposed algorithm reduces the parallelization penalty about two times over the basic algorithm for the range of the number of processors (subdomains) considered and the number of grid nodes per subdomain.

Morning REM Sleep Naps Facilitate Broad Access to Emotional Semantic Networks

PubMed Central

Carr, Michelle; Nielsen, Tore

2015-01-01

Study Objectives: The goals of the study were to assess semantic priming to emotion and nonemotion cue words using a novel measure of associational breadth for participants who either took rapid eye movement (REM) or nonrapid eye movement (NREM) naps or who remained awake, and to assess the relation of priming to REM sleep consolidation and REM sleep inertia effects. Design: The associational breadth task was applied in both a priming condition, where cue words were signaled to be memorized prior to sleep (primed), and a nonpriming condition, where cue words were not memorized (nonprimed). Cue words were either emotional (positive, negative) or nonemotional. Participants were randomly assigned to either an awake (WAKE) or a sleep condition, which was subsequently split into NREM or REM groups depending on stage at awakening. Setting: Hospital-based sleep laboratory. Participants: Fifty-eight healthy participants (22 male) ages 18 to 35 y (mean age = 23.3 ± 4.08 y). Measurements and Results: The REM group scored higher than the NREM or WAKE groups on primed, but not nonprimed emotional cue words; the effect was stronger for positive than for negative cue words. However, REM time and percent correlated negatively with degree of emotional priming. Priming occurred for REM awakenings but not for NREM awakenings, even when the latter sleep episodes contained some REM sleep. Conclusions: Associational breadth may be selectively consolidated during REM sleep for stimuli that have been tagged as important for future memory retrieval. That priming decreased with REM time and was higher only for REM sleep awakenings is consistent with two explanatory REM sleep processes: REM sleep consolidation serving emotional downregulation and REM sleep inertia. Citation: Carr M, Nielsen T. Morning REM sleep naps facilitate broad access to emotional semantic networks. SLEEP 2015;38(3):433–443. PMID:25409100

Sleep and Fatigue Differences in the Two Most Common Types of Commercial Flight Operations.

PubMed

Reis, Cátia; Mestre, Catarina; Canhão, Helena; Gradwell, David; Paiva, Teresa

2016-09-01

Sleep and fatigue management is one of the main challenges in airline operations scheduling. Our aim was to compare the differences regarding fatigue, sleep, and labor specificities between the two most common types of flight, short/medium haul (SM-H) and long haul (L-H), in a large sample of airline pilots. A self-report questionnaire was developed, composed of socio-economic and labor questions, and psychological assessment scales for fatigue and sleep. Associations of these variables and type of flight were tested. Of the total sample of Portuguese airline pilots (N = 435), 313 (72%) were from SM-H and 122 (28%) were from L-H. For SM-H, the values obtained for sleep complaints were 34.2%, daytime sleepiness 61.6%, and fatigue 93.0%. For L-H, 36.9%, 53.3%, and 84.4%, respectively. Looking at labor variables, the differences between the two types of flights were evident, with SM-H pilots' having statistically significant higher mean values of duty and flight hours, numbers of sectors, and early mornings. Only the mean number of night periods was higher in L-H pilots. All values were reported for 28 consecutive scheduling days. Night periods and time-zone crossing may explain higher prevalence levels of sleep disturbances in L-H pilots. However, the values for daytime sleepiness were higher in SM-H pilots, which may be attributed to diminished sleep caused by a combination of frequent early starts and long duty periods. Taking into account the large differences between the two types of flights, different regulatory limits should be considered by aviation authorities. Reis C, Mestre C, Canhão H, Gradwell D, Paiva T. Sleep and fatigue differences in the two most common types of commercial flight operations. Aerosp Med Hum Perform. 2016; 87(9):811-815.

Sleep and circadian rhythms in children and adolescents: relevance for athletic performance of young people.

PubMed

Carskadon, Mary A

2005-04-01

The amount and timing of sleep play significant roles in forming a solid foundation for competitive performance in young athletes. As children mature into and through adolescence, their need for sleep does not decline substantially, although the opportunity to sleep is limited by lifestyle choices, academic and practice schedules, and compelling changes in the biological processes. The biological changes include a more "permissive" pace for the accumulation of sleep pressure across the day in older adolescents and a longer day length in the more mature. These factors all favor later bedtimes and rising times as children pass into adolescence, and a concomitant delay in the optimal timing for waking activities. Among the important threats to athletic performance are insufficient sleep during training and competition and poor appreciation for the best time of day for competitive activities. The specific consequences of these issues for individual athletes are not clear, though when considering young people as a group, support for adequate sleep is a rational intervention to maximize performance.

Intrinsic near-24-h pacemaker period determines limits of circadian entrainment to a weak synchronizer in humans

NASA Technical Reports Server (NTRS)

Wright, K. P. Jr; Hughes, R. J.; Kronauer, R. E.; Dijk, D. J.; Czeisler, C. A.

2001-01-01

Endogenous circadian clocks are robust regulators of physiology and behavior. Synchronization or entrainment of biological clocks to environmental time is adaptive and important for physiological homeostasis and for the proper timing of species-specific behaviors. We studied subjects in the laboratory for up to 55 days each to determine the ability to entrain the human clock to a weak circadian synchronizing stimulus [scheduled activity-rest cycle in very dim (approximately 1.5 lux in the angle of gaze) light-dark cycle] at three approximately 24-h periods: 23.5, 24.0, and 24.6 h. These studies allowed us to test two competing hypotheses as to whether the period of the human circadian pacemaker is near to or much longer than 24 h. We report here that imposition of a sleep-wake schedule with exposure to the equivalent of candle light during wakefulness and darkness during sleep is usually sufficient to maintain circadian entrainment to the 24-h day but not to a 23.5- or 24.6-h day. Our results demonstrate functionally that, in normally entrained sighted adults, the average intrinsic circadian period of the human biological clock is very close to 24 h. Either exposure to very dim light and/or the scheduled sleep-wake cycle itself can entrain this near-24-h intrinsic period of the human circadian pacemaker to the 24-h day.

PC-PVT 2.0: An updated platform for psychomotor vigilance task testing, analysis, prediction, and visualization.

PubMed

Reifman, Jaques; Kumar, Kamal; Khitrov, Maxim Y; Liu, Jianbo; Ramakrishnan, Sridhar

2018-07-01

The psychomotor vigilance task (PVT) has been widely used to assess the effects of sleep deprivation on human neurobehavioral performance. To facilitate research in this field, we previously developed the PC-PVT, a freely available software system analogous to the "gold-standard" PVT-192 that, in addition to allowing for simple visual reaction time (RT) tests, also allows for near real-time PVT analysis, prediction, and visualization in a personal computer (PC). Here we present the PC-PVT 2.0 for Windows 10 operating system, which has the capability to couple PVT tests of a study protocol with the study's sleep/wake and caffeine schedules, and make real-time individualized predictions of PVT performance for such schedules. We characterized the accuracy and precision of the software in measuring RT, using 44 distinct combinations of PC hardware system configurations. We found that 15 system configurations measured RTs with an average delay of less than 10 ms, an error comparable to that of the PVT-192. To achieve such small delays, the system configuration should always use a gaming mouse as the means to respond to visual stimuli. We recommend using a discrete graphical processing unit for desktop PCs and an external monitor for laptop PCs. This update integrates a study's sleep/wake and caffeine schedules with the testing software, facilitating testing and outcome visualization, and provides near-real-time individualized PVT predictions for any sleep-loss condition considering caffeine effects. The software, with its enhanced PVT analysis, visualization, and prediction capabilities, can be freely downloaded from https://pcpvt.bhsai.org. Published by Elsevier B.V.

Simulation of textile manufacturing processes for planning, scheduling, and quality control purposes

NASA Astrophysics Data System (ADS)

Cropper, A. E.; Wang, Z.

1995-08-01

Simulation, as a management information tool, has been applied to engineering manufacture and assembly operations. The application of the principles to textile manufacturing (fiber to fabric) is discussed. The particular problems and solutions in applying the simulation software package to the yarn production processes are discussed with an indication of how the software achieves the production schedule. The system appears to have application in planning, scheduling, and quality assurance. The latter being a result of the traceability possibilities through a process involving mixing and splitting of material.

Co-Sleeping among School-Aged Anxious and Non-Anxious Children: Associations with Sleep Variability and Timing.

PubMed

Palmer, Cara A; Clementi, Michelle A; Meers, Jessica M; Alfano, Candice A

2018-01-05

Little is known about the co-sleeping behaviors of school-aged children, particularly among anxious youth who commonly present for the treatment of sleep problems. The current study examined the occurrence of co-sleeping in both healthy and clinically anxious children and its associated sleep patterns. A total of 113 children (ages 6-12), 75 with primary generalized anxiety disorder and 38 healthy controls, participated along with their primary caregiver. Families completed structured diagnostic assessments, and parents reported on their child's co-sleeping behaviors and anxiety severity. Children provided reports of anxiety severity and completed one week of wrist-based actigraphy to assess objective sleep patterns. A significantly greater proportion of anxious youth compared to healthy children co-slept, and greater anxiety severity was related to more frequent co-sleeping. Co-sleeping in anxious youth was associated with a delay in sleep timing and with greater sleep variability (i.e., more variable nightly sleep duration). All analyses controlled for child age, race/ethnicity, family income, and parental marital status. Co-sleeping is highly common in anxious school-aged children, with more than 1 in 3 found to co-sleep at least sometimes (2-4 times a week). Co-sleeping was even more common for youth with greater anxiety severity. Increased dependence on others to initiate and maintain sleep may contribute to poorer sleep in this population via shifted schedules and more variable sleep patterns.

Analysis of Alternative Watch Schedules for Shipboard Operations: A Guide for Commanders

DTIC Science & Technology

2012-03-01

legally impaired in the U.S. Memory and creativity are both negatively impacted by sleep deprivation (Butcher, 2000; Stickgold, 2005; Wagner, Gais ...section watch sections, which were analyzed in the FAST program. A. SAN JACINTO SURVEY DATA SET While on deployment in 2010, CAPT Cordle, the... Thomas , M., Sing, H., Redmond, D., Balkin, T. (2003). Patterns of performance degradation and restoration during sleep restriction and subsequent

Wireless Sensor Networks for High Fidelity Sampling

DTIC Science & Technology

2007-07-20

Transmission Schedule . . . . . . . . . . 156 8.3 CSMA versus TDMA . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 8.4 Practical Issues...goes into sleep mode when no job is running. Let W be the wakeup time; then the peak at 0 moves to W . In fact the entire graph can be moved to the left...tio n Immediate Context Switching Wakeup from Sleep Context Switching after Finishing Atomic Section Figure 2.9. Histogram of Jitter at 5kHz Sampling

Evaluation of obstructive sleep apnea in obese patients scheduled for bariactric surgery.

PubMed

Lopes Neto, José Maurício; Brandão, Leandro Ortega; Loli, Alessandra; Leite, Celso Vieira de Souza; Weber, Silke Anna Theresa

2013-04-01

To evaluate the frequency of obstructive sleep apnea (OSA) in obese patients scheduled for bariatric surgery and their identification for risk of OSA by Berlin Questionnaire (BQ) and excessive daytime sleepiness by Epworth Sleepiness Scale (ESS). Fifty nine patients were evaluated by BQ and ESS. Out of these individuals, 35 performed a full-night sleep study using a type 3 portable monitoring (PM). The questionnaire results were compared for gender and BMI. The presence and severity of OSA was correlated with gender and both questionnaires. 94.75% of the respondents presented high risk for OSA by BQ and 59.65% presented positivity by ESS. Taking into account the AHI> 5 per hour for OSA diagnosis, all of them presented OSA, average AHI of 45.31 ± 26.3 per hour and 68.6% have severe OSA (AHI>30). The male patients had a higher AHI (p<0.05). There was a positive correlation between the positivity in both questionnaires as well as the severity of OSA measured by AHI (p<0.05). The frequency and severe obstructive sleep apnea in the studied group is high. The Berlin Questionnaire and Epworth Sleepiness Scale had a positive correlation with the diagnosis of OSA in the group studied.

Formula for the prediction of apnea / hypopnea index in children with obstructive sleep apnea without polysomnography according to the clinical parameters: Is it reliable?

PubMed

Kljajić, Zlatko; Roje, Željka; Bečić, Kristijan; Čapkun, Vesna; Vilović, K; Ivanišević, Petar; Marušić, Eugenija

2017-09-01

The aim of the study was to propose "the risk formula" for obstructive sleep apnea in children according to the general and local clinical parameters and findings relevant for obstructive sleep apnea (OSA) severity. The unmet need for this formula arises from the economic burden of polysomnography (device, staff, training, special sleep centers, etc) as the golden standard for the diagnostics. The study was performed from January 2013 until January 2016 in the Sleep Center, Department for Neuroscience, School of Medicine of the University of Split, Department of Pediatrics, University Hospital Split, Croatia and ENT Dept. University Hospital in Split, Croatia. Inclusion criteria were: age > two years, AHI >1 diagnosed by polysomnography. Exclusion criteria were: chronic lung disease, active tonsillitis/pharyngitis at the time of the physical exam and syndromes that affect breathing. All polysomnograms were scored by a qualified sleep technologist and interpreted by two board certified sleep physicians independently. Age, sex, BMI, Mallampati score, tonsillar size and adenoids size were recorded. All statistical calculations were performed using SPSS 20. In total 60 children were included in the study. The median of age was 5 years (range 2-9). There were 19 (32%) girls and 41 (68%) boys. Of all evaluated predictors, there were statistically significant differences in the values of AHI among children with different modified Mallampati score (χ2 = 28.2; p < 0.001), different size of tonsils (χ2 = 25.3; p < 0.001) and different size of adenoids (z = 2.7; p = 0,006) in univariate regression analysis. Strong positive association of AHI with modified Mallampati score (standardized B = 0.51; partial correlation = 0.542, r = 0.631) was found, as well as positive correlation of AHI with tonsillar size (standardized B = 0.246; partial correlation = 0.295,R = 0.489) in the multivariate forward stepwise regression analysis. Even though we are aware that PSG is the gold standard for diagnostics of SDB there is a significant financial burden for this diagnostic procedure. That is why there is a necessity for establishing good clinical standards and possible formula for OSA severity evaluation. We propose formula which includes Mallampati score and tonsillar size for OSA -risk calculation in order to perform early therapeutic intervention thereby reducing the risk of long-term negative consequences. We recommend this formula as the screening formula in circumstances where PSG is not available, in cases when the "waiting list" is too long or when a child can not cooperate to perform it. In developing countries like Croatia on time intervention with reduced procedure-associated costs is of the utmost importance. Copyright © 2017 Elsevier B.V. All rights reserved.

Unhealthy sleep practices, conduct problems, and daytime functioning during adolescence.

PubMed

Lin, Wen-Hsu; Yi, Chin-Chun

2015-02-01

Although sleep has been linked to activities in various domains of life, one under-studied link is the relationship between unhealthy sleep practices and conduct problems among adolescents. The present study investigates the influence of adolescents' unhealthy sleep practices-short sleep (e.g., less than 6 h a day), inconsistent sleep schedule (e.g., social jetlag), and sleep problems-on conduct problems (e.g., substance use, fighting, and skipping class). In addition, this study examines unhealthy sleep practices in relationship to adolescent emotional well-being, defiant attitudes, and academic performance, as well as these three domains as possible mediators of the longitudinal association between sleep practices and conduct problems. Three waves of the Taiwan Youth Project (n = 2,472) were used in this study. At the first time-point examined in this study, youth (51% male) were aged 13-17 (M = 13.3). The results indicated that all three measures of unhealthy sleep practices were related to conduct problems, such that short sleep, greater social jetlag, and more serious sleep problems were concurrently associated with greater conduct problems. In addition, short sleep and sleep problems predicted conduct problems one year later. Furthermore, these three unhealthy sleep practices were differently related to poor academic performance, low levels of emotional well-being, and defiant attitudes, and some significant indirect effects on later conduct problems through these three attributes were found. Cultural differences and suggestions for prevention are discussed.

Replay of conditioned stimuli during late REM and stage N2 sleep influences affective tone rather than emotional memory strength.

PubMed

Rihm, Julia S; Rasch, Björn

2015-07-01

Emotional memories are reprocessed during sleep, and it is widely assumed that this reprocessing occurs mainly during rapid eye movement (REM) sleep. In support for this notion, vivid emotional dreams occur mainly during REM sleep, and several studies have reported emotional memory enhancement to be associated with REM sleep or REM sleep-related parameters. However, it is still unknown whether reactivation of emotional memories during REM sleep strengthens emotional memories. Here, we tested whether re-presentation of emotionally learned stimuli during REM sleep enhances emotional memory. In a split-night design, participants underwent Pavlovian conditioning after the first half of the night. Neutral sounds served as conditioned stimuli (CS) and were either paired with a negative odor (CS+) or an odorless vehicle (CS-). During sound replay in subsequent late REM or N2 sleep, half of the CS+ and half of the CS- were presented again. In contrast to our hypothesis, replay during sleep did not affect emotional memory as measured by the differentiation between CS+ and CS- in expectancy, arousal and valence ratings. However, replay unspecifically decreased subjective arousal ratings of both emotional and neutral sounds and increased positive valence ratings also for both CS+ and CS- sounds, respectively. These effects were slightly more pronounced for replay during REM sleep. Our results suggest that re-exposure to previously conditioned stimuli during late sleep does not affect emotional memory strength, but rather influences the affective tone of both emotional and neutral memories. Copyright © 2015 Elsevier Inc. All rights reserved.

The effects of sleep dysfunction on cognition, affect, and quality of life in individuals with cerebellar ataxia.

PubMed

Sonni, Akshata; Kurdziel, Lauri B F; Baran, Bengi; Spencer, Rebecca M C

2014-05-15

Cerebellar ataxia comprises a group of debilitating diseases that are the result of progressive cerebellar degeneration. Recent studies suggest that, like other neurodegenerative diseases, sleep impairments are common in cerebellar ataxia. In light of the role of sleep in mood regulation and cognition, we sought to assess interactions between sleep, cognition, and affect in individuals with cerebellar ataxia. A survey of 176 individuals with cerebellar ataxia was conducted. The battery of instruments included a modified International Cooperative Ataxia Rating Scale, Pittsburgh Sleep Quality Index, Restless Leg Syndrome Questionnaire, REM Behavior Disorder Questionnaire, Beck Depression Inventory, Epworth Sleepiness Scale, and a Composite Cognitive Questionnaire. Fifty-one percent of individuals indicated significant sleep disturbances on the Pittsburgh Sleep Quality Index, 73% of participants had two or more symptoms of restless leg syndrome, and 88% had two or more symptoms of REM behavior disorder. Ataxia severity, based on the modified International Cooperative Ataxia Rating Scale, predicted scores on the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale and REM Behavior Disorder Questionnaire. Median split analyses revealed that cognitive function appeared to be reduced and depressive symptoms were greater for those individuals with poor subjective sleep quality and severe RLS. Importantly, sleep appears to play a mediatory role between disease severity and depressive symptoms. These results suggest that disturbed sleep may have detrimental effects on cognition and affect in individuals with cerebellar ataxia. While objective measures are needed, such results suggest that treating sleep deficits in these individuals may improve cognitive and mental health as well as overall quality of life.

Insomnia in shift work.

PubMed

Vallières, Annie; Azaiez, Aïda; Moreau, Vincent; LeBlanc, Mélanie; Morin, Charles M

2014-12-01

Shift work disorder involves insomnia and/or excessive sleepiness associated with the work schedule. The present study examined the impact of insomnia on the perceived physical and psychological health of adults working on night and rotating shift schedules compared to day workers. A total of 418 adults (51% women, mean age 41.4 years), including 51 night workers, 158 rotating shift workers, and 209 day workers were selected from an epidemiological study. An algorithm was used to classify each participant of the two groups (working night or rotating shifts) according to the presence or absence of insomnia symptoms. Each of these individuals was paired with a day worker according to gender, age, and income. Participants completed several questionnaires measuring sleep, health, and psychological variables. Night and rotating shift workers with insomnia presented a sleep profile similar to that of day workers with insomnia. Sleep time was more strongly related to insomnia than to shift work per se. Participants with insomnia in the three groups complained of anxiety, depression, and fatigue, and reported consuming equal amounts of sleep-aid medication. Insomnia also contributed to chronic pain and otorhinolaryngology problems, especially among rotating shift workers. Work productivity and absenteeism were more strongly related to insomnia. The present study highlights insomnia as an important component of the sleep difficulties experienced by shift workers. Insomnia may exacerbate certain physical and mental health problems of shift workers, and impair their quality of life. Copyright © 2014 Elsevier B.V. All rights reserved.

Changes of Cerebral and/or Peripheral Adenosine A₁ Receptor and IGF-I Concentrations under Extended Sleep Duration in Rats.

PubMed

Chennaoui, Mounir; Arnal, Pierrick J; Dorey, Rodolphe; Sauvet, Fabien; Ciret, Sylvain; Gallopin, Thierry; Leger, Damien; Drogou, Catherine; Gomez-Merino, Danielle

2017-11-17

Extended sleep improves sustained attention and reduces sleep pressure in humans. Downregulation of adenosine A₁ receptor (A₁R) and modulation of the neurotrophic factor insulin growth factor-1 (IGF-I) in brain structures controlling attentional capacities could be involved. In the frontal cortex and hippocampus of rats, we measured adenosine A₁R and IGF-I protein concentrations after photoperiod-induced sleep extension. Two groups of twelve rats were adapted over 14 days to a habitual (CON) 12:12 light-dark (LD) schedule and an extended (EXT) 16:8 LD schedule. IGF-I content was also measured in plasma, liver, and skeletal muscle. In EXT, compared to CON rats, A₁R content in the frontal cortex was significantly lower ( p < 0.05), while IGF-I content was higher ( p < 0.001), and no significant change was observed in the hippocampus. IGF-I content in plasma and muscle was higher ( p < 0.001 and p < 0.01), while it was lower in liver ( p < 0.001). The absolute weight and weight gain were higher in EXT rats ( p < 0.01). These data suggest that 14 days under a 16:8 LD photoperiod respectively down- and upregulated cortical A₁R and IGF-I levels. This photoperiod induced an anabolic profile with increased weight gain and circulating and muscular IGF-I levels. An extension of sleep duration might favor cerebral and peripheral anabolism, which may help attentional and physical capacities.

A Video Method to Study Drosophila Sleep

PubMed Central

Zimmerman, John E.; Raizen, David M.; Maycock, Matthew H.; Maislin, Greg; Pack, Allan I.

2008-01-01

Study Objectives: To use video to determine the accuracy of the infrared beam-splitting method for measuring sleep in Drosophila and to determine the effect of time of day, sex, genotype, and age on sleep measurements. Design: A digital image analysis method based on frame subtraction principle was developed to distinguish a quiescent from a moving fly. Data obtained using this method were compared with data obtained using the Drosophila Activity Monitoring System (DAMS). The location of the fly was identified based on its centroid location in the subtracted images. Measurements and Results: The error associated with the identification of total sleep using DAMS ranged from 7% to 95% and depended on genotype, sex, age, and time of day. The degree of the total sleep error was dependent on genotype during the daytime (P < 0.001) and was dependent on age during both the daytime and the nighttime (P < 0.001 for both). The DAMS method overestimated sleep bout duration during both the day and night, and the degree of these errors was genotype dependent (P < 0.001). Brief movements that occur during sleep bouts can be accurately identified using video. Both video and DAMS detected a homeostatic response to sleep deprivation. Conclusions: Video digital analysis is more accurate than DAMS in fly sleep measurements. In particular, conclusions drawn from DAMS measurements regarding daytime sleep and sleep architecture should be made with caution. Video analysis also permits the assessment of fly position and brief movements during sleep. Citation: Zimmerman JE; Raizen DM; Maycock MH; Maislin G; Pack AI. A video method to study drosophila sleep. SLEEP 2008;31(11):1587–1598. PMID:19014079

Morning rapid eye movement sleep naps facilitate broad access to emotional semantic networks.

PubMed

Carr, Michelle; Nielsen, Tore

2015-03-01

The goal of the study was to assess semantic priming to emotion and nonemotion cue words using a novel measure of associational breadth for participants who either took rapid eye movement (REM) or nonrapid eye movement (NREM) naps or who remained awake; assess relation of priming to REM sleep consolidation and REM sleep inertia effects. The associational breadth task was applied in both a priming condition, where cue-words were signaled to be memorized prior to sleep (primed), and a nonpriming condition, where cue words were not memorized (nonprimed). Cue words were either emotional (positive, negative) or nonemotional. Participants were randomly assigned to either an awake (WAKE) or a sleep condition, which was subsequently split into NREM or REM groups depending on stage at awakening. Hospital-based sleep laboratory. Fifty-eight healthy participants (22 male) ages 18 to 35 y (Mage = 23.3 ± 4.08 y). The REM group scored higher than the NREM or WAKE groups on primed, but not nonprimed emotional cue words; the effect was stronger for positive than for negative cue words. However, REM time and percent correlated negatively with degree of emotional priming. Priming occurred for REM awakenings but not for NREM awakenings, even when the latter sleep episodes contained some REM sleep. Associational breadth may be selectively consolidated during REM sleep for stimuli that have been tagged as important for future memory retrieval. That priming decreased with REM time and was higher only for REM sleep awakenings is consistent with two explanatory REM sleep processes: REM sleep consolidation serving emotional downregulation and REM sleep inertia. © 2015 Associated Professional Sleep Societies, LLC.

Fatigue mitigation with SleepTrackTXT2 in air medical emergency care systems: study protocol for a randomized controlled trial.

PubMed

Patterson, P Daniel; Moore, Charity G; Guyette, Frank X; Doman, Jack M; Sequeira, Denisse; Werman, Howard A; Swanson, Doug; Hostler, David; Lynch, Joshua; Russo, Lindsey; Hines, Linda; Swecker, Karen; Runyon, Michael S; Buysse, Daniel J

2017-06-05

Most air medical Emergency Medical Services (EMS) clinicians work extended duration shifts, and more than 50% report inadequate sleep, poor sleep quality, and/or poor recovery between shifts. The SleepTrackTXT pilot trial (ClinicalTrials.gov, NCT02063737) showed that use of mobile phone text messages could impact EMS clinician self-reported fatigue and sleepiness during long duration shifts. The purpose of the SleepTrackTXT2 trial is to leverage lessons learned from the first SleepTrackTXT study and test an enhanced intervention targeting air medical EMS clinicians. We will conduct a multi-site randomized trial with a sample of adult EMS clinicians recruited from four air medical EMS systems located in the midwest, northeastern, and southern USA. Participants will be allocated to one of two possible arms for a 4-month (120-day) study period. The intervention arm will involve text-message assessments of sleepiness, fatigue, and difficulty concentrating at the beginning, every 4 hours during, and at the end of scheduled shifts. Participants reporting high levels of sleepiness, fatigue, or difficulty with concentration will receive one of nine randomly selected intervention messages to promote behavior change during shift work to improve alertness. Intervention participants will receive a text-message report on Friday of each week that shows their sleep debt over the previous 7 days followed by a text message to promote paying back sleep debt recovery when feasible. Participants in the control group receive text messages that only include assessments. Both arms will receive text-message assessments of perceived recovery since last shift, sleepiness, fatigue, or difficulty with concentration at noon (1200 hours) on days between scheduled shifts (off-duty days). We have two aims for this study: (1) to determine the short-term impact of the enhanced SleepTrackTXT2 intervention on air medical clinician fatigue reported in real time during and at the end of shift work, and (2) to determine the long-term impact of the SleepTrackTXT2 intervention on sleep quality and sleep health indicators including hours of sleep and recovery between shift work. The SleepTrackTXT2 trial may provide evidence of real-world effectiveness that would support widespread expansion of fatigue mitigation interventions in emergency care clinician shift workers. The trial may specifically support use of real-time assessments and interventions delivered via mobile technology such as text messaging. ClinicalTrials.gov, NCT02783027 . Registered on 23 May 2016.

Sleeping Habits among School Children and their Effects on Sleep Pattern.

PubMed

Mishra, Apurva; Pandey, Ramesh Kumar; Minz, Anurag; Arora, Varuni

2017-12-01

Introduction: Sleep problems can occur at any age. Inadequate sleep affects the physiological as well as psychological well-being of an individual. Thus, the objective of the present study is, to determine the pre sleep habits, duration and pattern of sleep among school children and to determine association between their sleep schedules and sleep habits. Methods: This cross-sectional study comprised of 1050 children attending the government school. Based on inclusion and exclusion criteria children were from three age groups: 4-5 years, 6-10 years and 11-15 years of age. A questionnaire about demographical data, sleep problems and habits, was duly filled by the parents. The parents of children were questioned for bed time, wakeup time, sleep time and sleep duration during both weekdays and weekends. Results: Total sleep time during weekdays was 8.9 (1.2) hours and 10.7 (1.1) hours during weekends. The wakeup time was significantly delayed during weekends in all age groups. Moreover, total sleep time increased significantly during weekends in all age groups. Children using media after 8 pm and sleeping alone are also in significant sleep debt. Screen activities such as TV, internet and cellular phones in a child's bedroom had a negative effect on children's sleep/wake patterns and duration of sleep. Children in higher grades are sleep debt compared to younger ones. Practices such as co sleeping and sharing bed with parents significantly improve the duration and quality of sleep. Conclusion: The sleep durations reported in the present study were lower than recommended sleep duration for children.

Individual traits and environmental factors influencing sleep timing: a study of 225 Japanese couples.

PubMed

Hida, Akiko; Kitamura, Shingo; Enomoto, Minori; Nozaki, Kentaro; Moriguchi, Yoshiya; Echizenya, Masaru; Kusanagi, Hiroaki; Mishima, Kazuo

2012-03-01

Behavioral and physiological processes, such as sleep-wakefulness, thermoregulation, and hormone secretion, exhibit 24-h rhythms in most organisms. These biological rhythms are driven by the circadian clock system and are entrained by the external environment, which in the case of humans includes social time schedules. Couples might be ideal experimental subjects to discriminate between individual traits and environmental factors, as they share lifestyle habits but not genetic backgrounds. In this study, sleep timing was compared between married Japanese couples (n = 225) who had lived together for 1 yr or more (mean 17 yrs). Additionally, the authors evaluated the influence of individual traits and environmental factors on an individual's sleep timing per each couple. The results reveal that the sleep timings of a couple are mainly associated with the chronotypes of the husband and wife, whereas the sleep timings are significantly influenced by certain environmental factors. The findings suggest that chronotype remains one of the major determinants of an individual's sleep onset and wake times. Understanding an individual's chronotype may help improve the quality of life issues surrounding sleep.

Sleep and wakefulness in aircrew before and after transoceanic flights

NASA Technical Reports Server (NTRS)

Dement, William C.; Seidel, Wesley F.; Cohen, Suzanne A.; Carskadon, Mary A.; Bliwise, Nancy G.

1986-01-01

The effects of rapid transmeridian flight on sleep and wakefulness were studied in aircrew members before and after flying one of two routes: San Francisco (SFO) to London (LHR) or SFO to Tokyo. After an adaptation night, sleep and daytime sleepiness were measured objectively in SFO and during the first layover (L/O) of the target trip, using the 'core measures' described by Graeber et al. (1986) and respiration parameters, and the Multiple Sleep Latency Test (MSLT) described by Carscadon (1982); postsleep questionnaires provided subjective assessments. It was found that baseline sleep is not an ideal basis for subsequent comparison; nevertheless, there was an indication that L/O sleep periods tended to provide either less total sleep or less efficient sleep. During baseline, there was significant midday sleepiness tendency as measured by the MSLT; this tendency occurred at almost the same time on the second L/O day in LHR. Recommendations are offered for the adjustment of flight times and for scheduling times of permitted napping as accommodations for the periods of sleepiness tendency.

Association of sleep and academic performance.

PubMed

Eliasson, Arne; Eliasson, Anders; King, Joseph; Gould, Ben; Eliasson, Arn

2002-03-01

Poor school performance by adolescent students has been attributed in part to insufficient sleep. It is recognized that a number of factors lead to diminished total sleep time and chief among these are early school start times and sleep phase delay in adolescence. Political initiatives are gaining momentum across the United States to require later school start times with the intent of increasing total sleep time and consequently improving school performance. Later school start times come with significant costs and impact other activities of families and communities. The decision to implement later school start times cannot be made lightly and deserves support of well-performed research on the impact of these changes. A study evaluating the association of academic performance and total sleep time was performed in middle school and high school students in a suburban Maryland school system. Preliminary results of this study show no correlation of total sleep time with academic performance. Before mandating costly changes in school schedules, it would be useful to perform further research to determine the effects of increasing sleep time on the behaviors of adolescent students.

Sleep and Circadian Contributions to Adolescent Alcohol Use Disorder

PubMed Central

Hasler, Brant P.; Soehner, Adriane M.; Clark, Duncan B.

2014-01-01

Adolescence is a time of marked changes across sleep, circadian rhythms, brain function, and alcohol use. Starting at puberty, adolescents’ endogenous circadian rhythms and preferred sleep times shift later, often leading to a mismatch with the schedules imposed by secondary education. This mismatch induces circadian misalignment and sleep loss, which have been associated with affect dysregulation, increased drug and alcohol use, and other risk-taking behaviors in adolescents and adults. In parallel to developmental changes in sleep, adolescent brains are undergoing structural and functional changes in the circuits subserving the pursuit and processing of rewards. These developmental changes in reward processing likely contribute to the initiation of alcohol use during adolescence. Abundant evidence indicates that sleep and circadian rhythms modulate reward function, suggesting that adolescent sleep and circadian disturbance may contribute to altered reward function, and in turn, alcohol involvement. In this review, we summarize the relevant evidence and propose that these parallel developmental changes in sleep, circadian rhythms, and neural processing of reward interact to increase risk for alcohol use disorder (AUD). PMID:25442171

Age, circadian rhythms, and sleep loss in flight crews

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Nguyen, DE; Rosekind, Mark R.; Connell, Linda J.

1993-01-01

Age-related changes in trip-induced sleep loss, personality, and the preduty temperature rhythm were analyzed in crews from various flight operations. Eveningness decreased with age. The minimum of the baseline temperature rhythm occurred earlier with age. The amplitude of the baseline temperature rhythm declined with age. Average daily percentage sleep loss during trips increased with age. Among crewmembers flying longhaul flight operations, subjects aged 50-60 averaged 3.5 times more sleep loss per day than subjects aged 20-30. These studies support previous findings that evening types and subjects with later peaking temperature rhythms adapt better to shift work and time zone changes. Age and circadian type may be important considerations for duty schedules and fatigue countermeasures.

Sleep/Wake Patterns and Parental Perceptions of Sleep in Children Born Preterm.

PubMed

Biggs, Sarah N; Meltzer, Lisa J; Tapia, Ignacio E; Traylor, Joel; Nixon, Gillian M; Horne, Rosemary S C; Doyle, Lex W; Asztalos, Elizabeth; Mindell, Jodi A; Marcus, Carole L

2016-05-15

To compare sleep/wake patterns in children born preterm in Australia vs Canada and determine cultural differences in the relationship between parental perception of sleep and actual sleep behaviors. Australian and Canadian children born preterm were recruited from the Caffeine for Apnea of Prematurity trial (n = 188, 5-12 y) and underwent 14 days actigraphy monitoring. Parents completed the National Sleep Foundation 2004 Sleep in America questionnaire. Cross-cultural differences in sleep characteristics assessed by actigraphy and parent-reported questionnaire were examined. Correlational analyses determined the associations between parental perceptions of child sleep need and sleep behavior. Actigraphy showed preterm children obtained, on average, 8 h sleep/night, one hour less than population recommendations for their age. There was no difference in total sleep time (TST) between Australian and Canadian cohorts; however, bed and wake times were earlier in Australian children. Bedtimes and TST varied by 60 minutes from night to night in both cohorts. Parent-reported child TST on the National Sleep Foundation questionnaire was 90 minutes longer than recorded by actigraphy. Both bedtime and TST on weekdays and weekends were related to parental perception of child sleep need in the Australian cohort. Only TST on weekdays was related to parental perception of child sleep need in the Canadian cohort. This study suggests that short sleep duration and irregular sleep schedules are common in children born preterm. Cultural differences in the association between parental perception of child sleep need and actual sleep behaviors provide important targets for future sleep health education. © 2016 American Academy of Sleep Medicine.

Naps promote flexible memory retrieval in 12-month-old infants.

PubMed

Konrad, Carolin; Seehagen, Sabine; Schneider, Silvia; Herbert, Jane S

2016-11-01

Flexibility in applying existing knowledge to similar cues is a corner stone of memory development in infants. Here, we examine the effect of sleep on the flexibility of memory retrieval using a deferred imitation paradigm. Forty-eight 12-month-old infants were randomly assigned to either a nap or a no-nap demonstration condition (scheduled around their natural daytime sleep schedule) or to a baseline control condition. In the demonstration conditions, infants watched an experimenter perform three target actions on a hand puppet. Immediately afterwards, infants were allowed to practice the target actions three times. In a test session 4-hr later, infants were given the opportunity to reproduce the actions with a novel hand puppet differing in color from the puppet used during the demonstration session. Only infants in the nap-condition performed significantly more target actions than infants in the baseline control condition. Furthermore, they were faster to carry out the first target action than infants in the no-nap condition. We conclude that sleep had a facilitative effect on infants' flexibility of memory retrieval. © 2016 Wiley Periodicals, Inc.

REM Sleep Phase Preference in the Crepuscular Octodon degus Assessed by Selective REM Sleep Deprivation

PubMed Central

Ocampo-Garcés, Adrián; Hernández, Felipe; Palacios, Adrian G.

2013-01-01

Study Objectives: To determine rapid eye movement (REM) sleep phase preference in a crepuscular mammal (Octodon degus) by challenging the specific REM sleep homeostatic response during the diurnal and nocturnal anticrepuscular rest phases. Design: We have investigated REM sleep rebound, recovery, and documented REM sleep propensity measures during and after diurnal and nocturnal selective REM sleep deprivations. Subjects: Nine male wild-captured O. degus prepared for polysomnographic recordings Interventions: Animals were recorded during four consecutive baseline and two separate diurnal or nocturnal deprivation days, under a 12:12 light-dark schedule. Three-h selective REM sleep deprivations were performed, starting at midday (zeitgeber time 6) or midnight (zeitgeber time 18). Measurements and Results: Diurnal and nocturnal REM sleep deprivations provoked equivalent amounts of REM sleep debt, but a consistent REM sleep rebound was found only after nocturnal deprivation. The nocturnal rebound was characterized by a complete recovery of REM sleep associated with an augment in REM/total sleep time ratio and enhancement in REM sleep episode consolidation. Conclusions: Our results support the notion that the circadian system actively promotes REM sleep. We propose that the sleep-wake cycle of O. degus is modulated by a chorus of circadian oscillators with a bimodal crepuscular modulation of arousal and a unimodal promotion of nocturnal REM sleep. Citation: Ocampo-Garcés A; Hernández F; Palacios AG. REM sleep phase preference in the crepuscular Octodon degus assessed by selective REM sleep deprivation. SLEEP 2013;36(8):1247-1256. PMID:23904685

Amplitude Reduction and Phase Shifts of Melatonin, Cortisol and Other Circadian Rhythms after a Gradual Advance of Sleep and Light Exposure in Humans

PubMed Central

Dijk, Derk-Jan; Duffy, Jeanne F.; Silva, Edward J.; Shanahan, Theresa L.; Boivin, Diane B.; Czeisler, Charles A.

2012-01-01

Background The phase and amplitude of rhythms in physiology and behavior are generated by circadian oscillators and entrained to the 24-h day by exposure to the light-dark cycle and feedback from the sleep-wake cycle. The extent to which the phase and amplitude of multiple rhythms are similarly affected during altered timing of light exposure and the sleep-wake cycle has not been fully characterized. Methodology/Principal Findings We assessed the phase and amplitude of the rhythms of melatonin, core body temperature, cortisol, alertness, performance and sleep after a perturbation of entrainment by a gradual advance of the sleep-wake schedule (10 h in 5 days) and associated light-dark cycle in 14 healthy men. The light-dark cycle consisted either of moderate intensity ‘room’ light (∼90–150 lux) or moderate light supplemented with bright light (∼10,000 lux) for 5 to 8 hours following sleep. After the advance of the sleep-wake schedule in moderate light, no significant advance of the melatonin rhythm was observed whereas, after bright light supplementation the phase advance was 8.1 h (SEM 0.7 h). Individual differences in phase shifts correlated across variables. The amplitude of the melatonin rhythm assessed under constant conditions was reduced after moderate light by 54% (17–94%) and after bright light by 52% (range 12–84%), as compared to the amplitude at baseline in the presence of a sleep-wake cycle. Individual differences in amplitude reduction of the melatonin rhythm correlated with the amplitude of body temperature, cortisol and alertness. Conclusions/Significance Alterations in the timing of the sleep-wake cycle and associated bright or moderate light exposure can lead to changes in phase and reduction of circadian amplitude which are consistent across multiple variables but differ between individuals. These data have implications for our understanding of circadian organization and the negative health outcomes associated with shift-work, jet-lag and exposure to artificial light. PMID:22363414

Cognitive consequences of sleep deprivation, shiftwork, and heat exposure for underground miners.

PubMed

Legault, Glenn; Clement, Alexandra; Kenny, Glen P; Hardcastle, Stephen; Keller, Nancy

2017-01-01

Sleep deprivation, abnormal sleep patterns arising from working rotating shifts, and exposure to high ambient temperatures contribute to physical and cognitive dysfunction. We examined the effects of these on 19 (41.5 ± 5.1 years) male underground miners. Data were collected for 28 to 30 consecutive days such that the participants experienced their full rotating shift schedule, including days off. Objective measures of sleep quality (actigraphy), attentional capacity (psychomotor vigilance task), core body temperature (visceral pill), executive function (BRIEF-A) and subjective measures of fatigue (Karolinska and Epworth Sleepiness scales) were obtained over the 28-30 day period. Non-parametric analyses (χ(2), Wilcoxen Signed ranks) were used to determine differences between shift types and days off. Z-tests were used to compare sample data to population norms. These revealed that the participants experienced poor quality of sleep relative to age-matched norms irrespective of the shift being worked or if the participant was on a scheduled day off [30-39 year olds: z = -14.62, p < 0.001; 40-49 year olds: z = -4.44, p < 0.001]. Participants when working day shift experienced less sleep prior to beginning work compared to their days off or night shift; however, no differences in total sleep time between when participants worked day or night shifts were observed [χ(2) (2, n = 18) = 13.44, p < 0.01]. When measured subjectively, the only time participants reported excessive sleepiness was after a night shift. Objective measures of attentional capacity showed best performance at the beginning of night shifts in contrast to any other time that the task was completed; however, performance degraded dramatically over the course of the night shift [χ(2) (2, n = 12) = 6.50, p < 0.05]. We show that underground miners reported for work sleep deprived. The cognitive consequences of this poor sleep were most pronounced during night shift when their attentional capacity declined rapidly over the course of the night shift. Copyright © 2016 Elsevier Ltd. All rights reserved.

A User Oriented Review of the Literature on the Effects of Sleep Loss, Work-Rest Schedules, and Recovery on Performance

DTIC Science & Technology

1974-12-01

Martin , 0. E. and Alluisi, E. A., "Human Performance as a Function of the Work-Rest Cycle: A Review of Selected Studies," National Academy.of Sciences...WilKinson, R. T., "One Stress on Top of Another," New So0eety, 12 JOly 1972, 72-75 52. Wilkinson, R. T., "Sleep Deprivation-Eight Questions," MRC

Fundamentals of Shiftwork Scheduling

DTIC Science & Technology

2006-04-01

C-Shiftwork and Safety Biology and Shiftwork. In terms of human biology, night work is a crime against nature. We cannot see well in the dark. Our...to the National Sleep Foundation, the risk of workplace accidents and automobile crashes rises for tired shifiworkers, especially on the drive to and...sleep increases your risk for falling asleep at the wheel, accidents on the job, and problems at home. There are several steps a shiftworker can take to

Relationship of chronotype to sleep pattern in a cohort of college students during work days and vacation days.

PubMed

Yadav, Arjita; Singh, Sudhi

2014-05-01

To study whether the chronotype is linked with the sleep characteristics among college going students assessed during college days and vacation days, adult female students at undergraduate level were asked to answer the Hindi/English version of the Munich Chronotype Questionnaire (MCTQ), fill a sleep log, and drinking and feeding logs for three weeks covering college and vacation days. Based on chronotype categorization as morning type, intermediate type and evening type, sleep onset and offset times, sleep duration and mid-sleep times for each group were compared, separately for college and vacation days. Results indicate that the sleep duration of the morning types was significantly longer than the evening types, both, during college and vacation days. Similarly, the sleep onset and sleep offset times were significantly earlier in the morning types than the evening type students. During the vacation days, the individuals exhibited longer sleep duration with delayed mid-sleep times. Further there was no significant difference among the chronotypes regarding their feeding and drinking frequency per cent during the college and the vacation days. It is suggested that the students should be made aware of their chronotype, so that they can utilize their time optimally, and develop a schedule more suitable to their natural needs.

Crew factors in flight operations. 8: Factors influencing sleep timing and subjective sleep quality in commercial long-haul flight crews

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Graeber, R. Curtis; Connell, Linda J.; Gregory, Kevin B.

1991-01-01

How flight crews organize their sleep during layovers on long-haul trips is documented. Additionally, environmental and physiological constraints on sleep are examined. In the trips studied, duty periods averaging 10.3 hr alternated with layovers averaging 24.8 hr, which typically included two subject-defined sleep episodes. The circadian system had a greater influence on the timing and duration of first-sleeps than second-sleeps. There was also a preference for sleeping during the local night. The time of falling asleep for second-sleeps was related primarily to the amount of sleep already obtained in the layover, and their duration depended on the amount of time remaining in the layover. For both first- and second-sleeps, sleep durations were longer when subjects fell asleep earlier with respect to the minimum of the circadian temperature cycle. Naps reported during layovers and on the flight deck may be a useful strategy for reducing cumulative sleep loss. The circadian system was not able to synchronize with the rapid series of time-zone shifts. The sleep/wake cycle was forced to adopt a period different from that of the circadian system. Flight and duty time regulations are a means of ensuring that reasonable minimum rest periods are provided. This study clearly documents that there are physiologically and environmentally determined preferred sleep times within a layover. The actual time available for sleep is thus less than the scheduled rest period.

Circadian and Wake-Dependent Influences on Subjective Sleepiness, Cognitive Throughput, and Reaction Time Performance in Older and Young Adults

PubMed Central

Silva, Edward J.; Wang, Wei; Ronda, Joseph M.; Wyatt, James K.; Duffy, Jeanne F.

2010-01-01

Study Objectives: To assess circadian and homeostatic influences on subjective sleepiness and cognitive performance in older adults when sleep and waking are scheduled at different times of day; to assess changes in subjective sleepiness and cognitive performance across several weeks of an inpatient study; and to compare these findings with results from younger adults. Design: Three 24-h baseline days consisting of 16 h of wakefulness and an 8-h sleep opportunity followed by 3-beat cycles of a 20-h forced desynchrony (FD) condition; 18 20-h “days,” each consisting of 13.33 h of scheduled wakefulness and 6.67 h of scheduled sleep opportunity. Setting: Intensive Physiological Monitoring Unit of the Brigham and Women's Hospital General Clinical Research Center. Participants: 10 healthy older adults (age 64.00 ± 5.98 y, 5 females) and 10 healthy younger adults (age 24.50 ± 3.54 y, 5 females). Interventions: Wake episodes during FD scheduled to begin 4 h earlier each day allowing for data collection at a full range of circadian phases. Measurements and Results: Subjective sleepiness, cognitive throughput, and psychomotor vigilance assessed every 2 h throughout the study. Core body temperature (CBT) data collected throughout to assess circadian phase. Older subjects were less sleepy and performed significantly better on reaction time (RT) measures than younger subjects. Decrements among younger subjects increased in magnitude further into the experiment, while the performance of older subjects remained stable. Conclusions: Our findings demonstrate that the waking performance and alertness of healthy older subjects are less impacted by the cumulative effects of repeated exposure to adverse circadian phase than that of young adults. This suggests that there are age-related changes in the circadian promotion of alertness, in the wake-dependent decline of alertness, and/or in how these 2 regulatory systems interact in healthy aging. Citation: Silva EJ; Wang W; Ronda JM; Wyatt JK; Duffy JF. Circadian and wake-dependent influences on subjective sleepiness, cognitive throughput, and reaction time performance in older and young adults. SLEEP 2010;33(4):481-490. PMID:20394317

Sleep spindles in midday naps enhance learning in preschool children

PubMed Central

Kurdziel, Laura; Duclos, Kasey; Spencer, Rebecca M. C.

2013-01-01

Despite the fact that midday naps are characteristic of early childhood, very little is understood about the structure and function of these sleep bouts. Given that sleep benefits memory in young adults, it is possible that naps serve a similar function for young children. However, children transition from biphasic to monophasic sleep patterns in early childhood, eliminating the nap from their daily sleep schedule. As such, naps may contain mostly light sleep stages and serve little function for learning and memory during this transitional age. Lacking scientific understanding of the function of naps in early childhood, policy makers may eliminate preschool classroom nap opportunities due to increasing curriculum demands. Here we show evidence that classroom naps support learning in preschool children by enhancing memories acquired earlier in the day compared with equivalent intervals spent awake. This nap benefit is greatest for children who nap habitually, regardless of age. Performance losses when nap-deprived are not recovered during subsequent overnight sleep. Physiological recordings of naps support a role of sleep spindles in memory performance. These results suggest that distributed sleep is critical in early learning; when short-term memory stores are limited, memory consolidation must take place frequently. PMID:24062429

Sleep/wake behaviour of endurance cyclists before and during competition.

PubMed

Lastella, Michele; Roach, Gregory Daniel; Halson, Shona Leigh; Martin, David Thomas; West, Nicholas Peter; Sargent, Charli

2015-01-01

Good sleep is critical for optimising recovery and athletic performance. Yet, few studies have investigated how athletes sleep before and during competition. The aim of this study was to determine whether such sleep is poorer than that before a usual training day. Twenty-one male endurance cyclists' (age: 19.9 ± 1.7 years) sleep/wake behaviour was assessed using wrist activity monitors for 11 nights, including a six-night baseline training phase, three nights before competition and two nights during competition. Cyclists had less sleep on the night before competition (6.5 ± 0.9 h) and during the first night of competition (6.8 ± 0.8 h) than at baseline (7.4 ± 0.6 h). Cyclists also went to bed and woke up earlier during competition than at baseline. Competition schedules and competition itself can disrupt the sleep/wake behaviour of athletes during competition. Future investigations should examine sleep during three stages of competition (i.e. before, during and after competition). This will help coaches develop a greater understanding of how sleep changes during different phases of competition and enable them to plan post-competition training programmes to ensure appropriate rest and recovery is obtained.

Sleep spindles in midday naps enhance learning in preschool children.

PubMed

Kurdziel, Laura; Duclos, Kasey; Spencer, Rebecca M C

2013-10-22

Despite the fact that midday naps are characteristic of early childhood, very little is understood about the structure and function of these sleep bouts. Given that sleep benefits memory in young adults, it is possible that naps serve a similar function for young children. However, children transition from biphasic to monophasic sleep patterns in early childhood, eliminating the nap from their daily sleep schedule. As such, naps may contain mostly light sleep stages and serve little function for learning and memory during this transitional age. Lacking scientific understanding of the function of naps in early childhood, policy makers may eliminate preschool classroom nap opportunities due to increasing curriculum demands. Here we show evidence that classroom naps support learning in preschool children by enhancing memories acquired earlier in the day compared with equivalent intervals spent awake. This nap benefit is greatest for children who nap habitually, regardless of age. Performance losses when nap-deprived are not recovered during subsequent overnight sleep. Physiological recordings of naps support a role of sleep spindles in memory performance. These results suggest that distributed sleep is critical in early learning; when short-term memory stores are limited, memory consolidation must take place frequently.

Relation between adherence and outcome in the group treatment of insomnia.

PubMed

Vincent, Norah K; Hameed, Hannah

2003-01-01

This study evaluated adherence to group cognitive behavioral treatment in 50 adults with chronic insomnia. Adherence was measured using questionnaire data, consistency of sleep scheduling, and % of sessions attended. Results showed that therapists' rated 48% of participants as "very much" to "extremely" adherent. Using stepwise regression, only therapist-rated adherence explained a significant amount of variance in post-treatment outcome. Therapist-rated adherence predicted post-treatment ratings of sleep-related impairment, dysfunctional beliefs about sleep, and overall sleep quality (but not actual sleep duration or efficiency). Using a multivariate analysis of variance (MANOVA) procedure, results revealed that a diagnosis of dysthymia, based on a structured clinical interview, was associated with reduced adherence and less improvement in sleep-onset latency and sleep efficiency, but that scores on a dimensional measure of depression were not associated with either adherence or outcome. Implications of these findings are that the practice of treatment techniques is related to an improved perception of sleep and more healthy and appropriate beliefs about the causes of poor sleep. Therapists should continue to pay close attention to the adherence behavior of those with insomnia, particularly if they are depressed.

Sleep Strategies of Night-Shift Nurses on Days Off: Which Ones are Most Adaptive?

PubMed

Petrov, Megan E; Clark, C Brendan; Molzof, Hylton E; Johnson, Russell L; Cropsey, Karen L; Gamble, Karen L

2014-01-01

To determine the off-shift sleep strategies of bi-ethnic night-shift nurses, the relationship between these sleep strategies and adaptation to shift work, and identify the participant-level characteristics associated with a given sleep strategy. African-American and non-Hispanic White female, night-shift nurses from an academic hospital were recruited to complete a survey on sleep-wake patterns (n = 213). Participants completed the standard shiftwork index and the biological clocks questionnaire to determine sleep strategies and adaptation to night-shift work. In addition, chronotype was determined quantitatively with a modified version of the Munich ChronoType Questionnaire. Most participants worked ~3 consecutive 12-h night-shifts followed by several days off. Five sleep strategies used on days off were identified: (a) night stay, (b) nap proxy, (c) switch sleeper, (d) no sleep, and (e) incomplete switcher. Nap proxy and no sleep types were associated with poorer adaptation to night-shift work. The switch sleeper and incomplete switcher types were identified as more adaptive strategies that were associated with less sleep disturbance, a later chronotype, and less cardiovascular problems. Behavioral sleep strategies are related to adaptation to a typical night-shift schedule among hospital nurses. Nurses are crucial to the safety and well-being of their patients. Therefore, adoption of more adaptive sleep strategies may reduce sleep/wake dysregulation in this population, and improve cardiovascular outcomes.

Napping on the Night Shift: A Study of Sleep, Performance, and Learning in Physicians-in-Training.

PubMed

McDonald, Jennifer; Potyk, Darryl; Fischer, David; Parmenter, Brett; Lillis, Teresa; Tompkins, Lindsey; Bowen, Angela; Grant, Devon; Lamp, Amanda; Belenky, Gregory

2013-12-01

Physicians in training experience fatigue from sleep loss, high workload, and working at an adverse phase of the circadian rhythm, which collectively degrades task performance and the ability to learn and remember. To minimize fatigue and sustain performance, learning, and memory, humans generally need 7 to 8 hours of sleep in every 24-hour period. In a naturalistic, within-subjects design, we studied 17 first- and second-year internal medicine residents working in a tertiary care medical center, rotating between day shift and night float every 4 weeks. We studied each resident for 2 weeks while he/she worked the day shift and for 2 weeks while he/she worked the night float, objectively measuring sleep by wrist actigraphy, vigilance by the Psychomotor Vigilance Task test, and visual-spatial and verbal learning and memory by the Brief Visuospatial Memory Test-Revised and the Rey Auditory-Verbal Learning Test. Residents, whether working day shift or night float, slept approximately 7 hours in every 24-hour period. Residents, when working day shift, consolidated their sleep into 1 main sleep period at night. Residents working night float split their sleep, supplementing their truncated daytime sleep with nighttime on-duty naps. There was no difference in vigilance or learning and memory, whether residents worked day shift or night float. Off-duty sleep supplemented with naps while on duty appears to be an effective strategy for sustaining vigilance, learning, and memory when working night float.

Does the circadian clock drift when pilots fly multiple transpacific flights with 1- to 2-day layovers?

PubMed

Gander, Philippa; Mulrine, Hannah M; van den Berg, Margo J; Wu, Lora; Smith, Alexander; Signal, Leigh; Mangie, Jim

2016-01-01

On trips with multiple transmeridian flights, pilots experience successive non-24 h day/night cycles with circadian and sleep disruption. One study across a 9-day sequence of transpacific flights (no in-flight sleep, 1-day layovers between flights) reported an average period in the core body temperature rhythm of 24.6 h (circadian drift). Consequently, pilots were sometimes flying through the circadian performance nadir and had to readapt to home base time at the end of the trip. The present study examined circadian drift in trip patterns with longer flights and in-flight sleep. Thirty-nine B747-400 pilots (19 captains, 20 first officers, mean age = 55.5 years) were monitored on 9- to 13-day trips with multiple return flights between East Coast USA and Japan (in 4-pilot crews) and between Japan and Hawaii (in 3-pilot crews), with 1-day layovers between each flight. Measures included total in-flight sleep (actigraphy, log books) and top of descent (TOD) measures of sleepiness (Karolinska Sleepiness Scale), fatigue (Samn-Perelli Crew Status Check) and psychomotor vigilance task (PVT) performance. Circadian rhythms of individual pilots were not monitored. To detect circadian drift, mixed-model analysis of variance examined whether for a given flight, total in-flight sleep and TOD measures varied according to when the flight occurred in the trip sequence. In addition, sleep propensity curves for pre-trip and post-trip days were examined (Chi-square periodogram analyses). Limited data suggest that total in-flight sleep of relief crew at landing may have decreased across successive East Coast USA-Japan (flights 1, 3, 5 or 7; median arrival 03:45 Eastern Daylight Time (EDT)). However, PVT response speed at TOD was faster on East Coast USA-Japan flights later in the trip. On these flights, circadian drift would result in flights later in the trip landing closer to the evening wake maintenance zone, when sleep is difficult and PVT response speeds are fastest. On Japan-East Coast USA flights (flights 2, 4, 6 or 8; median arrival time 14:52 EDT), PVT response speeds were slower on flight 8 than on flight 2. Circadian drift would move these arrivals progressively earlier in the SCN pacemaker cycle, where PVT response speeds are slower. Across the five post-trip days, 12 pilots (Group A) immediately resumed their pre-trip sleep pattern of a single nocturnal sleep episode; 9 pilots (Group B) had a daytime nap on most days that moved progressively earlier until it merged with nocturnal sleep and 17 pilots (Group C) had nocturnal sleep and intermittent naps. Chi-square periodogram analyses of the sleep propensity curves for each group across baseline and post-trip days suggest full adaptation to EDT from post-trip day 1 (dominant period = 24 h). However, in Groups B and C, the patterns of split sleep post-trip compared to pre-trip suggest that this may be misleading. We conclude that the trends in total in-flight sleep and significant changes in PVT performance speed at TOD provide preliminary evidence for circadian drift, as do persistent patterns of split sleep post-trip. However, new measures to track circadian rhythms in individual pilots are needed to confirm these findings.

Energy-efficient orthogonal frequency division multiplexing-based passive optical network based on adaptive sleep-mode control and dynamic bandwidth allocation

NASA Astrophysics Data System (ADS)

Zhang, Chongfu; Xiao, Nengwu; Chen, Chen; Yuan, Weicheng; Qiu, Kun

2016-02-01

We propose an energy-efficient orthogonal frequency division multiplexing-based passive optical network (OFDM-PON) using adaptive sleep-mode control and dynamic bandwidth allocation. In this scheme, a bidirectional-centralized algorithm named the receiver and transmitter accurate sleep control and dynamic bandwidth allocation (RTASC-DBA), which has an overall bandwidth scheduling policy, is employed to enhance the energy efficiency of the OFDM-PON. The RTASC-DBA algorithm is used in an optical line terminal (OLT) to control the sleep mode of an optical network unit (ONU) sleep and guarantee the quality of service of different services of the OFDM-PON. The obtained results show that, by using the proposed scheme, the average power consumption of the ONU is reduced by ˜40% when the normalized ONU load is less than 80%, compared with the average power consumption without using the proposed scheme.

Circadian rhythms and sleep patterns in urban Greek couples.

PubMed

Lee, Kathryn A; Beyene, Yewoubdar; Paparrigopoulos, Thomas J; Dikeos, Dimitris G; Soldatos, Constantin R

2007-07-01

A convenience sample of 14 adults (seven couples) who intentionally nap regularly was recruited to describe circadian rhythms and sleep patterns in a culture in which afternoon naps are routine. Participants wore a wrist actigraph for 48 hr during May to obtain two peaks and troughs of activity data. Peak activity, estimated by cosinor analysis (acrophase), occurred at 1542 hours for men and at 1600 hours for women. Compared to their male partners, women had a later acrophase and a significantly stronger 24-hr rhythm, despite similar nap and nighttime sleep schedules. Men had more awakenings during the night and slightly shorter naps than did women. For the 24-hr period, men averaged 6.8 +/- 1.0 hr of sleep and women averaged 7.4 +/- 1.1 hr. Results indicate that Greek adults delay sleep onset at night and awaken early in the morning. Among this small group, naps are an accepted cultural behavior.

Common meanings of good and bad sleep in a healthy population sample.

PubMed

Dickerson, Suzanne S; Klingman, Karen J; Jungquist, Carla R

2016-09-01

The study's purpose was to understand the common meanings and shared practices related to good and bad sleep from narratives of a sample of healthy participants. Interpretive phenomenology was the approach to analyze narratives of the participants' everyday experiences with sleep. Participants were interviewed and asked to describe typical good and bad nights' sleep, what contributes to their sleep experience, and the importance of sleep in their lives. Team interpretations of narratives identified common themes by consensus. Medium sized city in New York State (upper west region). A sample of 30 healthy participants were from a parent study (n=300) on testing the sleep questions from the Behavioral Risk Factor Surveillance System from the Centers for Disease Control and Prevention. Interpretations of good and bad sleep. Participants described similar experiences of good and bad sleep often directly related to their ability to schedule time to sleep, fall asleep, and maintain sleep. Worrying about life stresses and interruptions prevented participants from falling asleep and staying asleep. Yet, based on current life priorities (socializers, family work focused, and optimum health seekers), they had differing values related to seeking sleep opportunities and strategizing to overcome challenges. The participants' priorities reflected the context of their main concerns and stresses in life that influenced the importance given to promoting sleep opportunities. Public health messages tailored to life priorities could be developed to promote healthy sleep practices. Copyright © 2016 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

The effects of double-shifts (15.5 hours) on sleep, fatigue and health.

PubMed

Kecklund, G; Ekstedt, M; Akerstedt, T; Dahlgren, A; Samuelson, B

2001-12-01

The aim of the present study was to investigate how "double-shifts" (15.5 hours) affects sleep, fatigue and self-rated health. The study was carried out on male construction workers of which 80% were long-distance commuters. The schedule involved two work periods and each work period involved two double shifts in a row. The subjects filled in a sleep/wake diary at 8 times across a year and a questionnaire at 3 times. They also wore an actigraph during one shift cycle. The results showed that sleepiness, and to a certain extent, mental fatigue increased during double shifts and accumulated across days. The short rest time (8.5 hours) between days caused insufficient sleep and approximately 5.5 hours of sleep was obtained between double shifts. Questionnaire data showed that complaints of insufficient sleep, exhaustion on awakening and pain symptoms increased across the year. It was concluded that a shift system involving double shifts has a negative effect on fatigue, recovery and health-related well-being.

Bilateral thalamic stroke transiently reduces arousals and NREM sleep instability.

PubMed

Luigetti, Marco; Di Lazzaro, Vincenzo; Broccolini, Aldobrando; Vollono, Catello; Dittoni, Serena; Frisullo, Giovanni; Pilato, Fabio; Profice, Paolo; Losurdo, Anna; Morosetti, Roberta; Testani, Elisa; Colicchio, Salvatore; Della Marca, Giacomo

2011-01-15

The vascularization of the human thalami is supplied by many perforating arteries, which exhibit complex distribution and many possible individual variations. One rare variant is the artery of Percheron that supplies the paramedian thalami bilaterally. Its ictal occlusion may result in a symmetric paramedian infarction, which generally leads to impairment of consciousness associated with hypersomnia. Our aim is to describe in detail sleep-wake schedules, sleep structure and microstructure in a 68-year-old patient with occlusion of Percheron's artery. EEG monitoring, performed 24 h after the onset of symptoms, showed severe disruption of the sleep-wake cycle, with episodes of sleep and wakefulness recurring irregularly during day and night. Thalamic nuclei are part of the human arousal system; medial thalamic nuclei play a pivotal role in sleep regulation at different levels. A diagnosis of paramedian thalamic infarction should be considered in patients who present with recurrent episodes of unresponsiveness. Copyright © 2010 Elsevier B.V. All rights reserved.

Air Force Shift Worker Fatigue Survey

DTIC Science & Technology

2005-08-01

ensuring that health care and counseling services are available to employees who work non-traditional schedules. "* " Employees may consider various ways for...responded: Shift workers 1stSgt/CC Environmental (noise, lighting, temp., etc.): 35% 35% Family: 15% 14% Health factors (diet, stress, insomnia): 8% 14...fatigue and equity problems reported by the shift workers . 14. An automated shift work scheduling tool is needed’°. Sleep Hygiene and Health Issues

Techniques for Combined Arms for Air Defense

DTIC Science & Technology

2016-07-29

loss remain in effect until communications are regained. Changes to ROE and supplemental fire control measures scheduled to go into effect after...communications are lost will be implemented as scheduled . Fire Control Orders Fire control orders are commands used to control engagements on a case...or a sleep matt over windshields (Figure 3-2). Camouflage is one of the basic weapons of war. The importance, the principles, and the techniques of

An investigation on sleep behaviors of the elderly hospitalized in Zahedan

PubMed Central

Sargazi, Maryam; Salehi, Shayesteh; Naji, Seyed Ali

2012-01-01

Background: Sleep is an essential need in every individual's life. A disorder in the natural sleep can cause physical and mental problems. The elderly are usually faced with more sleep problems. Therefore, the present study aimed to define sleep behavior among the elderly hospitalized in Zahedan. Materials and Methods: This is a descriptive analytical study conducted on 300 elderly people aged 60 years and over who were hospitalized in Zahedan. In this research convenience sampling method was used and the research tool was a questionnaire. The data were collected through interviews. Descriptive (frequency distribution) and inferential (X2) statistical tests were employed to analyze the data. Findings: The results showed that 62% of the hospitalized elderly people (total of 300) had sleep disorder. About 44.7%took sleep medication in order to sleep, and only 16.7% did not take sleeping medications. About 44.7% had no special schedule for the time of their sleeping and waking up, and 4.3% were involved in drug abuse and smoking, and had a big dinner before sleeping. There was a significant association between sleep disorder, gender, education, living in urban or rural areas, the cause of hospitalization, and suffering from a chronic disease Conclusions: Sleep disorder and inappropriate sleep related behaviors had a high prevalence among the elderly. With regard to the important role of sleep in the quality of life of the elderly, detection of the reasons of sleep disorder, motivating them to practice an appropriate sleep behavior, and preventing them from having inappropriate sleep related behaviors are crucial issues. PMID:23493461

Restricting Time in Bed in Early Adolescence Reduces Both NREM and REM Sleep but Does Not Increase Slow Wave EEG.

PubMed

Campbell, Ian G; Kraus, Amanda M; Burright, Christopher S; Feinberg, Irwin

2016-09-01

School night total sleep time decreases across adolescence (9-18 years) by 10 min/year. This decline is comprised entirely of a selective decrease in NREM sleep; REM sleep actually increases slightly. Decreasing sleep duration across adolescence is often attributed to insufficient time in bed. Here we tested whether sleep restriction in early adolescence produces the same sleep stage changes observed on school nights across adolescence. All-night sleep EEG was recorded in 76 children ranging in age from 9.9 to 14.0 years. Each participant kept 3 different sleep schedules that consisted of 3 nights of 8.5 h in bed followed by 4 nights of either 7, 8.5, or 10 h in bed. Sleep stage durations and NREM delta EEG activity were compared across the 3 time in bed conditions. Shortening time in bed from 10 to 7 hours reduced sleep duration by approximately 2 hours, roughly equal to the decrease in sleep duration we recorded longitudinally across adolescence. However, sleep restriction significantly reduced both NREM (by 83 min) and REM (by 47 min) sleep. Sleep restriction did not affect NREM delta EEG activity. Our findings suggest that the selective NREM reduction and the small increase in REM we observed longitudinally across 9-18 years are not produced by sleep restriction. We hypothesize that the selective NREM decline reflects adolescent brain maturation (synaptic elimination) that reduces the need for the restorative processes of NREM sleep. © 2016 Associated Professional Sleep Societies, LLC.

Performance of the Sleep-Mode Mechanism of the New IEEE 802.16m Proposal for Correlated Downlink Traffic

NASA Astrophysics Data System (ADS)

de Turck, Koen; de Vuyst, Stijn; Fiems, Dieter; Wittevrongel, Sabine; Bruneel, Herwig

There is a considerable interest nowadays in making wireless telecommunication more energy-efficient. The sleep-mode mechanism in WiMAX (IEEE 802.16e) is one of such energy saving measures. Recently, Samsung proposed some modifications on the sleep-mode mechanism, scheduled to appear in the forthcoming IEEE 802.16m standard, aimed at minimizing the signaling overhead. In this work, we present a performance analysis of this proposal and clarify the differences with the standard mechanism included in IEEE 802.16e. We also propose some special algorithms aimed at reducing the computational complexity of the analysis.

[Stress and fatigue in long distance 2-man cockpit crew].

PubMed

Samel, A; Wegmann, H H; Vejvoda, M; Wittiber, K

1996-01-01

Common rules on flight-duty times and rest requirements within the European Union are under intense discussion. In the deliberations, results from scientific investigations should be considered. As part of a research programme concerning legal aspects of two-pilot operations on long-haul routes, the purpose of the studies was to investigate two-crew extended range operations during transmeridian and transequatorial flight schedules. The studies were conducted with two German charter airlines on the transmeridian routes Düsseldorf (DUS)-Atlanta (ATL) and Hamburg (HAM)-Los Angeles (LAX), and on the north-south route Frankfurt (FRA)-Mahe (SEZ) including two consecutive night flights with a short layover. In total, 25 rotations (50 flights) have been investigated by pre-, in-, and post-flight data collection from the two pilots being the minimum required crew. Recordings included sleep, taskload, fatigue and stress by measurements of EEG, ECG, motor activity and subjective ratings. During the transmeridian schedules, pilots lost one night of sleep because of the return flights which were conducted at night. The resulting sleep deficit was 8.2 h. During the layover of the SEZ-rotation with a duration of 14 h on average, sleep was shortened by 2 h compared with baseline sleep. The two consecutive night flights resulted in a sleep loss of 9.3 h upon return to home base. Inflight ratings of taskload showed low levels during the atlantic flights, and moderate grades during the north-south transitions. Fatigue ratings exhibited an increasing level with progressing flight duration. Towards the end of long US-westcoast flights performed at day-time, and in all night flights, fatigue was enhanced compared to the "baseline" ratings collected during the DUS-ATL flights. Fatigue was scored at a critical level by several pilots, particularly during the return flight SEZ-FRA when fatigue was severely pronounced. The subjective fatigue ratings were confirmed by the objective measurements of motor activity, brain-wave activity (occurrences of micro-sleep) and heart rate which indicated drowsiness and a low state of vigilance and alertness during all night flights under study. From the findings it is concluded that duty schedules, as conducted on the route HAM-LAX (because of long duty hours), and particularly on the route FRA-SEZ, (because of consecutive night duties) are coming close to the limits of mental and physiological capacity. With respect to legal aspects, the results have significance and should promote further deliberations for advanced schemes of flight duty time limitations and rest requirements.

Stress at work and mental health status among female hospital workers.

PubMed Central

Estryn-Behar, M; Kaminski, M; Peigne, E; Bonnet, N; Vaichere, E; Gozlan, C; Azoulay, S; Giorgi, M

1990-01-01

Relations between working conditions and mental health status of female hospital workers were studied in a sample of 1505 women: 43% were nurses, 32% auxiliaries, and 7% ancillary staff; 13% were other qualified health care staff, mainly head nurses; 5% had occupations other than direct health care; 63% worked on the morning, 20% on the afternoon, and 17% on the night shift. Data were collected at the annual routine medical visit by the occupational health practitioner, using self administered questionnaires and clinical assessments. Five health indicators were considered: a high score to the general health questionnaire (GHQ); fatigue; sleep impairment; use of antidepressants, sleeping pills, or sedatives; and diagnosis of psychiatric morbidity at clinical assessment. Four indices of stress at work were defined: job stress, mental load, insufficiency in internal training and discussion, and strain caused by schedule. The analysis was conducted by multiple logistic regression, controlling for type of occupation, shift, number of years of work in hospital, daily travel time to work, age, marital status, number of children, and wish to move house. Sleep impairment was mostly linked to shift and strain due to schedule. For all other indicators of mental health impairment and especially high GHQ scores, the adjusted odds ratios increased significantly with the levels of job stress, mental load, and strain due to schedule. This evidence of association between work involving an excessive cumulation of stress factors and mental wellbeing should be considered in interventions aimed at improving the working conditions of hospital workers. PMID:2310704

Human longevity is associated with regular sleep patterns, maintenance of slow wave sleep, and favorable lipid profile

PubMed Central

Mazzotti, Diego Robles; Guindalini, Camila; Moraes, Walter André dos Santos; Andersen, Monica Levy; Cendoroglo, Maysa Seabra; Ramos, Luiz Roberto; Tufik, Sergio

2014-01-01

Some individuals are able to successfully reach very old ages, reflecting higher adaptation against age-associated effects. Sleep is one of the processes deeply affected by aging; however few studies evaluating sleep in long-lived individuals (aged over 85) have been reported to date. The aim of this study was to characterize the sleep patterns and biochemical profile of oldest old individuals (N = 10, age 85–105 years old) and compare them to young adults (N = 15, age 20–30 years old) and older adults (N = 13, age 60–70 years old). All subjects underwent full-night polysomnography, 1-week of actigraphic recording and peripheral blood collection. Sleep electroencephalogram spectral analysis was also performed. The oldest old individuals showed lower sleep efficiency and REM sleep when compared to the older adults, while stage N3 percentage and delta power were similar across the groups. Oldest old individuals maintained strictly regular sleep-wake schedules and also presented higher HDL-cholesterol and lower triglyceride levels than older adults. The present study revealed novel data regarding specific sleep patterns and maintenance of slow wave sleep in the oldest old group. Taken together with the favorable lipid profile, these results contribute with evidence to the importance of sleep and lipid metabolism regulation in the maintenance of longevity in humans. PMID:25009494

Aberrant light directly impairs mood and learning through melanopsin-expressing neurons.

PubMed

LeGates, Tara A; Altimus, Cara M; Wang, Hui; Lee, Hey-Kyoung; Yang, Sunggu; Zhao, Haiqing; Kirkwood, Alfredo; Weber, E Todd; Hattar, Samer

2012-11-22

The daily solar cycle allows organisms to synchronize their circadian rhythms and sleep-wake cycles to the correct temporal niche. Changes in day-length, shift-work, and transmeridian travel lead to mood alterations and cognitive function deficits. Sleep deprivation and circadian disruption underlie mood and cognitive disorders associated with irregular light schedules. Whether irregular light schedules directly affect mood and cognitive functions in the context of normal sleep and circadian rhythms remains unclear. Here we show, using an aberrant light cycle that neither changes the amount and architecture of sleep nor causes changes in the circadian timing system, that light directly regulates mood-related behaviours and cognitive functions in mice. Animals exposed to the aberrant light cycle maintain daily corticosterone rhythms, but the overall levels of corticosterone are increased. Despite normal circadian and sleep structures, these animals show increased depression-like behaviours and impaired hippocampal long-term potentiation and learning. Administration of the antidepressant drugs fluoxetine or desipramine restores learning in mice exposed to the aberrant light cycle, suggesting that the mood deficit precedes the learning impairments. To determine the retinal circuits underlying this impairment of mood and learning, we examined the behavioural consequences of this light cycle in animals that lack intrinsically photosensitive retinal ganglion cells. In these animals, the aberrant light cycle does not impair mood and learning, despite the presence of the conventional retinal ganglion cells and the ability of these animals to detect light for image formation. These findings demonstrate the ability of light to influence cognitive and mood functions directly through intrinsically photosensitive retinal ganglion cells.

PHIT for Duty, a Personal Health Intervention Tool for Psychological Health and Traumatic Brain Injury

DTIC Science & Technology

2013-04-01

Findings Post deployment health problems. The top three post deployment health problems mentioned were depression, anxiety and sleep issues... anxiety ) are immediately available to the iVA, which is able to determine how to proceed with the user. The iVA may choose to schedule a screening... anxiety , sleep quality, depression, and alcohol use). For each domain, the screening data are analyzed by the iVA and a subsequent detailed assessment

Regulation of Split Linear Systems Over Rings: Coefficient-Assignment and Observers,

DTIC Science & Technology

1980-02-22

we give for the first time , a method to obtain an observer for a finite -free strongly observable The K-linear map irQ is defined as system 5" ( F. G...NAME a ADORESS~if dif!ttrent from Controlling Office) IS1 SECURITY CLASS . (of this report) SIS.. DE CL ASSI ’I CATION/ODOWNGRADING SCHEDULE 16...Entered) IEEE rRANSACTIONS ON AUTOMATIC CONTROL . VOL. Ac-27 . No. 1. FEaRUAay 1982 Regutlation of Split Linear Systems Over Rings: Coefficient

Acute Sleep Deprivation Blocks Short- and Long-Term Operant Memory in Aplysia.

PubMed

Krishnan, Harini C; Gandour, Catherine E; Ramos, Joshua L; Wrinkle, Mariah C; Sanchez-Pacheco, Joseph J; Lyons, Lisa C

2016-12-01

Insufficient sleep in individuals appears increasingly common due to the demands of modern work schedules and technology use. Consequently, there is a growing need to understand the interactions between sleep deprivation and memory. The current study determined the effects of acute sleep deprivation on short and long-term associative memory using the marine mollusk Aplysia californica , a relatively simple model system well known for studies of learning and memory. Aplysia were sleep deprived for 9 hours using context changes and tactile stimulation either prior to or after training for the operant learning paradigm, learning that food is inedible (LFI). The effects of sleep deprivation on short-term (STM) and long-term memory (LTM) were assessed. Acute sleep deprivation prior to LFI training impaired the induction of STM and LTM with persistent effects lasting at least 24 h. Sleep deprivation immediately after training blocked the consolidation of LTM. However, sleep deprivation following the period of molecular consolidation did not affect memory recall. Memory impairments were independent of handling-induced stress, as daytime handled control animals demonstrated no memory deficits. Additional training immediately after sleep deprivation failed to rescue the induction of memory, but additional training alleviated the persistent impairment in memory induction when training occurred 24 h following sleep deprivation. Acute sleep deprivation inhibited the induction and consolidation, but not the recall of memory. These behavioral studies establish Aplysia as an effective model system for studying the interactions between sleep and memory formation. © 2016 Associated Professional Sleep Societies, LLC.

The effect of sleep restriction on neurobehavioural functioning in normally developing children and adolescents: insights from the Attention, Behaviour and Sleep Laboratory.

PubMed

Cassoff, J; Bhatti, J A; Gruber, R

2014-10-01

In the current paper, we first introduce the research themes of the attention, behaviour and sleep (ABS) laboratory, namely, sleep and ADHD, sleep and obesity, and sleep and academic performance. We then focus in on the topic to be reviewed in the current paper - the association between sleep restriction and neurobehavioral functioning (NBF) in typically developing children. We review the research thus far conducted by the ABS lab specific to this topic and posit the unique methodological contributions of the ABS lab (e.g. home-based assessment of sleep architecture and patterns, extensive phenotyping, etc.) in terms of advancing this research area. In the second section of the paper, we review 13 studies investigating the causal association between experimental sleep restriction and NBF in normally developing pediatric populations. Eight of the 13 studies found that sleep restriction causes impairments in neurobehavioural functioning. However, given the inconsistency in outcome measures, experimental protocols and statistical power, the studies reviewed herein are difficult to interpret. Strategies used by the ABS including implementing home assessments of sleep, restricting sleep relative to the participants' typical sleep schedules, blinding raters who assess NBF, and using valid and reliable NBF assessments are an attempt to address the gaps in this research area and clarify the causal relationship between sleep restriction and NBF in typically developing children and adolescents. Copyright © 2014. Published by Elsevier SAS.

Effects of a Single Night of Postpartum Sleep on Childless Women’s Daytime Functioning

PubMed Central

McBean, Amanda L.; Kinsey, Steven G.; Montgomery-Downs, Hawley E.

2017-01-01

Study Objectives The maternal postpartum period is characterized by sleep fragmentation, which is associated with daytime impairment, mental health disturbances, and changes in melatonin patterns. In addition to sleep fragmentation, women undergo a complex set of physiological and environmental changes upon entering the postpartum period, confounding our understanding of effects of postpartum sleep disturbance. The primary study aim was to understand the basic impact of a single night of postpartum-like sleep fragmentation on sleep architecture, nocturnal melatonin levels, mood, daytime sleepiness, and neurobehavioral performance. Measurements and Results For one week prior to entry into the laboratory, eleven healthy nulliparous women kept a stable sleep-wake schedule (verified via actigraphy). Participants contributed three consecutive nights of laboratory overnight polysomnography: (1) a habituation/sleep disorder screening night; (2) a baseline night; and (3) a sleep fragmentation night, when participants were awakened three times for ~30 min each. Self-reported sleep quality and mood (Profile of Mood States Survey) both decreased significantly after sleep fragmentation compared to baseline measurements. Unexpectedly, daytime sleepiness (Multiple Sleep Latency Test) decreased significantly after sleep fragmentation. Experimental fragmentation had no significant effect on time spent in nocturnal sleep stages, urinary 6-sulphatoxymelatonin concentration, or psychomotor vigilance test performance. Participants continued to provide actigraphy data, and daily PVTs and self-reported sleep quality assessments at home for one week following sleep fragmentation; these assessments did not differ from baseline values. Conclusions While there were no changes in measured physiological components of a single night of postpartum-like experimental sleep fragmentation, there were decreases in self-reported measures of mood and sleep quality. Future research should examine the effects of multiple nights of modeling postpartum-like sleep fragmentation on objective measures of sleep and daytime functioning. PMID:26776447

Assessment of physical and mental health in male university students with varying sleep habits.

PubMed

Matsumoto, Yuuki; Toyomasu, Kouji; Uchimura, Naohisa

2011-01-01

Healthy sleep habits entail not only sleeping for a sufficient period (quantity) but also regularity of the sleep cycle and getting sound sleep (quality). University students often have erratic schedules that cause irregular sleep patterns even though sleep durations remain relatively constant. This study compared the physical and mental health of 90 male university students with different sleep habits. We created sleep habit scales using the Tokyo Metropolitan Institute for Neuroscience life habits inventory (TMIN-LHI; Miyashita, 1994) by performing a factor analysis and classifying sleeping habits based on regularity, quality, and quantity. Four types of sleep habits were identified by cluster analysis; good sleep was characterized by regular and high quality sleep but of relatively short sleep duration; long sleep was regular and relatively long but of low quality; short sleep was of high quality but short and irregular, while poor sleep was irregular, of low quality, and relatively long. The good sleep group had a significantly lower average waist circumference, and lower systolic and diastolic blood pressure. The long and poor sleep groups, which both had low quality sleep, scored lower than the national standard on the mental component summary (MCS) calculated from the Social Functioning-36 (SF-36) short-form health survey. Furthermore, the average MCS score of the poor sleep group was significantly lower than that of any other sleep habit group. Subjects with poor sleep also scored lowest on the Self-rating Depression Scale (SDS). In addition, the short and poor sleep groups were prone to glucose or lipid metabolism disorders. Maintaining good physical and mental health without sound sleep and a regular sleep cycle is difficult, even if sleeping hours are kept constant. Therefore, we included the assessment of regularity and quality in addition to hours of sleep in order to develop appropriate sleep guidelines for improved physical and mental health.

Flight Schedule and the Circadian Clock Influence on Sleep Loss During Overnight Cargo Operations

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Gregory, Kevin B.; Rosekind, Mark R.; Shafto, Michael G. (Technical Monitor)

1995-01-01

Thirty-four flight crew members were monitored before, during, and after two 8-day overnight cargo duty patterns which involved multiple flights at night crossing no more than one time zone per 24 h. Rectal temperature, heart rate, and wrist activity were recorded every 2 min. Sleep quantity and quality, and nap timing, were noted in a logbook. To reduce the masking effects of physical activity on temperature, 0.28 C was added to each subject's raw temperature data whenever he reported being asleep. For both masked and unmasked data, daily temperature minima were estimated from the multiple complex demodulated waveform. The temperature minima did not show a progressive adaptation to night duty, which was interrupted by a night off after 5 nights on one trip pattern and after 3 nights on the other. On duty days, the average temperature minimum delayed by about 3 h, occurring near the end of the duty period. Daytime sleep episodes averaged 2.9 h shorter than nighttime sleep episodes, and were rated as lighter, less restorative, and poorer overall. Fifty-three percent of subjects slept more than once per 24 h while they were on night duty, compared to 17% when able to sleep at night. The total sleep per 24 h on duty days averaged 1.2 h less than pretrip. Twenty-nine percent of subjects lost more than 2 h of sleep per 24 h across the 8-day duty patterns. After night duty, subjects awoke around 1400 local time, even when they had slept 2-3 h less than a normal nocturnal sleep episode. Consequently, the duration of morning sleep episodes was correlated with the off-duty time (multiple r(sup 2)=0.44, F=37.23, p less than 0.0001). Anecdotally, crew members complained of being unable to sleep longer and not feeling well-rested. These wakeups were clustered 6 h after the temperature minimum, which suggests that they may have been a response to the circadian wakeup signal. Daytime layovers in which crew members were able to sleep again in the evening ended later (0200-0300) and were longer (average 19.2 h versus 14.8 h) than those in which they slept only once in the morning. Overnight cargo crew members are working around the time of the circadian nadir with an accumulating sleep debt. Two scheduling factors affect sleep loss during these operations: how long before the circadian wakeup signal crew members come off duty, and whether the layover lasts long enough to permit a second sleep episode in the early evening.

Circadian Rhythm Sleep Disorders: Part II, Advanced Sleep Phase Disorder, Delayed Sleep Phase Disorder, Free-Running Disorder, and Irregular Sleep-Wake Rhythm

PubMed Central

Sack, Robert L; Auckley, Dennis; Auger, R. Robert; Carskadon, Mary A.; Wright, Kenneth P.; Vitiello, Michael V.; Zhdanova, Irina V.

2007-01-01

Objective: This the second of two articles reviewing the scientific literature on the evaluation and treatment of circadian rhythm sleep disorders (CRSDs), employing the methodology of evidence-based medicine. We herein report on the accumulated evidence regarding the evaluation and treatment of Advamced Sleep Phase Disorder (ASPD), Delayed Sleep Phase Disorder (DSPD), Free-Running Disorder (FRD) and Irregular Sleep-Wake Rhythm ISWR). Methods: A set of specific questions relevant to clinical practice were formulated, a systematic literature search was performed, and relevant articles were abstracted and graded. Results: A substantial body of literature has accumulated that provides a rational basis the evaluation and treatment of CRSDs. Physiological assessment has involved determination of circadian phase using core body temperature and the timing of melatonin secretion. Behavioral assessment has involved sleep logs, actigraphy and the Morningness-Eveningness Questionnaire (MEQ). Treatment interventions fall into three broad categories: 1) prescribed sleep scheduling, 2) circadian phase shifting (“resetting the clock”), and 3) symptomatic treatment using hypnotic and stimulant medications. Conclusion: Circadian rhythm science has also pointed the way to rational interventions for CRSDs and these treatments have been introduced into the practice of sleep medicine with varying degrees of success. More translational research is needed using subjects who meet current diagnostic criteria. Citation: Sack R; Auckley D; Auger RR; Carskadon MA; Wright KP; Vitiello MV; Zhdanova IV. Circadian rhythm sleep disorders: Part II, advanced sleep phase disorder, delayed sleep phase disorder, free-running disorder, and irregular sleep-wake rhythm. SLEEP 2007;30(11):1484-1501. PMID:18041481

Sleep Well!: A Pilot Study of an Education Campaign to Improve Sleep of Socioeconomically Disadvantaged Children.

PubMed

Mindell, Jodi A; Sedmak, Rebecca; Boyle, Julia T; Butler, Rachel; Williamson, Ariel A

2016-12-15

Socioeconomically disadvantaged children are at risk for poor sleep hygiene and increased sleep problems. This pilot study examined the efficacy of Sleep Well!, a parent-based sleep education endeavor, which supplemented an outreach program that provides beds to socioeconomically disadvantaged children. In addition to receiving a bed, 152 children (mean age = 5.95 years, 57.2% boys) were randomly assigned to sleep education (3 messages: bedtime before 21:00; no caffeine; keep electronics out of the bedroom) or control (dental hygiene education) conditions. All education was provided at both the time of scheduling and delivery of a bed to each child. Parent-reported sleep data were collected at baseline and at 4-week follow-up. Provision of a bed was associated with reduced bedroom electronics and increased parent-reported nighttime sleep duration for all children. However, relative to control children, intervention children showed even greater reductions in electronics (baseline mean = 1.91 items, follow-up mean = 0.85 items) and improvements in sleep duration (baseline mean = 9.75 hours, follow-up mean = 10.19 hours). There was no intervention effect for caffeine consumption or bedtime from baseline to follow-up. Providing beds to socioeconomically disadvantaged children resulted in increased sleep duration and decreased use of electronics at bedtime, while the combination of a bed and brief parent sleep education conferred additional sleep benefits. Further study of brief child sleep interventions is warranted, particularly among socioeconomically disadvantaged children who are at risk for sleep problems. © 2016 American Academy of Sleep Medicine

Work-Family Conflict and Employee Sleep: Evidence from IT Workers in the Work, Family and Health Study.

PubMed

Buxton, Orfeu M; Lee, Soomi; Beverly, Chloe; Berkman, Lisa F; Moen, Phyllis; Kelly, Erin L; Hammer, Leslie B; Almeida, David M

2016-10-01

Work-family conflict is a threat to healthy sleep behaviors among employees. This study aimed to examine how Work-to-Family Conflict (demands from work that interfere with one's family/personal life; WTFC) and Family-to-Work Conflict (demands from family/personal life that interfere with work; FTWC) are associated with several dimensions of sleep among information technology workers. Employees at a U.S. IT firm (n = 799) provided self-reports of sleep sufficiency (feeling rested upon waking), sleep quality, and sleep maintenance insomnia symptoms (waking up in the middle of the night or early morning) in the last month. They also provided a week of actigraphy for nighttime sleep duration, napping, sleep timing, and a novel sleep inconsistency measure. Analyses adjusted for work conditions (job demands, decision authority, schedule control, and family-supportive supervisor behavior), and household and sociodemographic characteristics. Employees who experienced higher WTFC reported less sleep sufficiency, poorer sleep quality, and more insomnia symptoms. Higher WTFC also predicted shorter nighttime sleep duration, greater likelihood of napping, and longer nap duration. Furthermore, higher WTFC was linked to greater inconsistency of nighttime sleep duration and sleep clock times, whereas higher FTWC was associated with more rigidity of sleep timing mostly driven by wake time. Results highlight the unique associations of WTFC/FTWC with employee sleep independent of other work conditions and household and sociodemographic characteristics. Our novel methodological approach demonstrates differential associations of WTFC and FTWC with inconsistency of sleep timing. Given the strong associations between WTFC and poor sleep, future research should focus on reducing WTFC. © 2016 Associated Professional Sleep Societies, LLC.

Restricting Time in Bed in Early Adolescence Reduces Both NREM and REM Sleep but Does Not Increase Slow Wave EEG

PubMed Central

Campbell, Ian G.; Kraus, Amanda M.; Burright, Christopher S.; Feinberg, Irwin

2016-01-01

Study Objectives: School night total sleep time decreases across adolescence (9–18 years) by 10 min/year. This decline is comprised entirely of a selective decrease in NREM sleep; REM sleep actually increases slightly. Decreasing sleep duration across adolescence is often attributed to insufficient time in bed. Here we tested whether sleep restriction in early adolescence produces the same sleep stage changes observed on school nights across adolescence. Methods: All-night sleep EEG was recorded in 76 children ranging in age from 9.9 to 14.0 years. Each participant kept 3 different sleep schedules that consisted of 3 nights of 8.5 h in bed followed by 4 nights of either 7, 8.5, or 10 h in bed. Sleep stage durations and NREM delta EEG activity were compared across the 3 time in bed conditions. Results: Shortening time in bed from 10 to 7 hours reduced sleep duration by approximately 2 hours, roughly equal to the decrease in sleep duration we recorded longitudinally across adolescence. However, sleep restriction significantly reduced both NREM (by 83 min) and REM (by 47 min) sleep. Sleep restriction did not affect NREM delta EEG activity. Conclusions: Our findings suggest that the selective NREM reduction and the small increase in REM we observed longitudinally across 9–18 years are not produced by sleep restriction. We hypothesize that the selective NREM decline reflects adolescent brain maturation (synaptic elimination) that reduces the need for the restorative processes of NREM sleep. Citation: Campbell IG, Kraus AM, Burright CS, Feinberg I. Restricting time in bed in early adolescence reduces both NREM and REM sleep but does not increase slow wave EEG. SLEEP 2016;39(9):1663–1670. PMID:27397569

Sleep budgets in a globalizing world: biocultural interactions influence sleep sufficiency among Egyptian families

PubMed Central

Worthman, Carol M.; Brown, Ryan A.

2013-01-01

Declines in self-reported sleep quotas with globalizing lifestyle changes have focused attention on their possible role in rising global health problems such as obesity or depression. Cultural factors that act across the life course and support sleep sufficiency have received scant attention, nor have the potential interactions of cultural and biological factors in age-related changes in sleep behavior been systematically investigated. This study examines the effects of cultural norms for napping and sleeping arrangements along with sleep schedules, age, and gender on sleep budgets among Egyptian households. Data were collected in 2000 from 16 households with 78 members aged 3–56 years at two sites in Egypt (Cairo and an agrarian village). Each participant provided one week of continuous activity records and details of each sleep event. Records showed that nighttime sleep onsets were late and highly variable. Napping was common and, along with wake time flexibility, played a key role in maintaining sleep sufficiency throughout the life course into later middle age. Cosleeping was prevalent and exhibited contrasting associations with reduced duration and sufficiency of both nocturnal and total sleep, and with earlier, more regular, and less disrupted sleep. Daily sleep quotas met published guidelines and showed age-related changes similar to existing reports, but differed in how they were achieved. Cultural norms organizing sleep practices by age and gender appear to tap their intrinsic biological properties as well. Moreover, flexibility in how sleep was achieved contributed to sleep sufficiency. The findings suggest how biocultural dynamics can play key roles in sleep patterns that sustain favorable sleep quotas from infancy onwards in populations pursuing globalizing contemporary lifestyles. PMID:22651897

Socializing by Day May Affect Performance by Night: Vulnerability to Sleep Deprivation is Differentially Mediated by Social Exposure in Extraverts vs Introverts.

PubMed

Rupp, Tracy L; Killgore, William D S; Balkin, Thomas J

2010-11-01

to examine the effects of socially enriched versus socially impoverished environments on performance and alertness decline during sleep deprivation in extraverts versus introverts. participants (n = 29 men, n = 19 women) were assigned to socially enriched (n = 24; 13 introverts, 11 extraverts) or socially impoverished (n = 24; 12 introverts, 12 extraverts) conditions (activities matched) for 12 hours (1000-2200) on Day 1 followed by 22 hours of sleep deprivation (2200-2000; 36 h awake total), monitored by actigraphy. The median split of volunteers' Eysenck Extraversion scores was used for extravert/introvert categorization. The Psychomotor Vigilance Task (PVT), modified Maintenance of Wakefulness Test (MWT), and Stanford Sleepiness Scale (SSS) were administered every 2 hours throughout. PVT speed, transformed lapses, modified MWT sleep-onset latency, and SSS were analyzed using mixed-model analyses of variance, with covariates of age and total actigraphic activity during enrichment or impoverishment. residential sleep/performance testing facility. forty-eight healthy adults (aged 18-39). Twelve hours of socially enriched or isolated environments in extraverts and introverts prior to sleep deprivation. Social experience interacted with personality type to affect alertness and vigilance. Social enrichment, as compared with social impoverishment, was associated with more PVT lapses at 04:00 overall. Similarly, following social enrichment, PVT speed was significantly slower among extraverts than among introverts during sleep deprivation, but no personality-group differences emerged following social impoverishment. MWT sleep latency and SSS subjective sleepiness did not show significant personality or social-condition effects during sleep deprivation. the effect of social exposure on vulnerability or resiliency to sleep deprivation was modulated by introversion and extraversion. Extraverts exposed to social environments were more vulnerable to subsequent sleep deprivation than were introverts.

Classifying vulnerability to sleep deprivation using baseline measures of psychomotor vigilance.

PubMed

Patanaik, Amiya; Kwoh, Chee Keong; Chua, Eric C P; Gooley, Joshua J; Chee, Michael W L

2015-05-01

To identify measures derived from baseline psychomotor vigilance task (PVT) performance that can reliably predict vulnerability to sleep deprivation. Subjects underwent total sleep deprivation and completed a 10-min PVT every 1-2 h in a controlled laboratory setting. Participants were categorized as vulnerable or resistant to sleep deprivation, based on a median split of lapses that occurred following sleep deprivation. Standard reaction time, drift diffusion model (DDM), and wavelet metrics were derived from PVT response times collected at baseline. A support vector machine model that incorporated maximum relevance and minimum redundancy feature selection and wrapper-based heuristics was used to classify subjects as vulnerable or resistant using rested data. Two academic sleep laboratories. Independent samples of 135 (69 women, age 18 to 25 y), and 45 (3 women, age 22 to 32 y) healthy adults. In both datasets, DDM measures, number of consecutive reaction times that differ by more than 250 ms, and two wavelet features were selected by the model as features predictive of vulnerability to sleep deprivation. Using the best set of features selected in each dataset, classification accuracy was 77% and 82% using fivefold stratified cross-validation, respectively. In both datasets, DDM measures, number of consecutive reaction times that differ by more than 250 ms, and two wavelet features were selected by the model as features predictive of vulnerability to sleep deprivation. Using the best set of features selected in each dataset, classification accuracy was 77% and 82% using fivefold stratified cross-validation, respectively. Despite differences in experimental conditions across studies, drift diffusion model parameters associated reliably with individual differences in performance during total sleep deprivation. These results demonstrate the utility of drift diffusion modeling of baseline performance in estimating vulnerability to psychomotor vigilance decline following sleep deprivation. © 2015 Associated Professional Sleep Societies, LLC.

The Twenty-four Hour Workday: Proceedings of a Symposium on Variations in Work-Sleep Schedules

DTIC Science & Technology

1980-10-01

medical care, transportation facilities, and security); (2) technological (continuous process operations, e.g., steel production, petrochemical refineries...able, has stL-nulated measurement of variations across time series. In the 2 process , it has identified a wide and important range of behavioral and phy...dimensions. However, this is a complex and interdependent process and a comprehensive understanding of work/rest schedules will be ulti- mately dependent

Quantifying Sleep and Performance of West Point Cadets: A Baseline Study

DTIC Science & Technology

2004-06-01

5. Table of reported average bedtimes (n= 991) and wakeup times (n=991) of those who reported their caffeine use for the 30 days prior to reporting...Military Academy at West Point, New York, cadets assume a rigorous schedule full of competing demands—military, athletic, and academic. This...they are operating with a degraded cognitive function. At the United States Military Academy at West Point, New York, cadets assume a rigorous schedule

Memory-Based Structured Application Specific Integrated Circuit (ASIC) Study

DTIC Science & Technology

2008-10-01

memory interface, arbiter/ schedulers for rescheduling the memory requests according to some schedule policy, and memory channels for communicating...between the power-savings and the wakeup overhead with respect to both wakeup power and wakeup delay. For example, dream mode can save 50% more static...power than sleep mode, but at the expense of twice the wake delay and three times the wakeup energy. The user can specify power-gating modes for various components.

Feasibility Report and Environmental Assessment Nogales Wash and Tributaries.Nogales, Arizona (Revision)

DTIC Science & Technology

1988-09-07

Office) IS. SECURITY CLASS. (of the report) Unclassified IS.. DECLASSIIFICATION/DOWNGRADING SCHEDULE 16. DISTRIBUTION STATEMENT (of th,. Report... SCHEDULE 5-19 L. ECCNCV!, I EVALUATION 5-19 M. NATIONAL ECONCMIC DEELOPMEN 5-19 N. RECOMMENDED PLAN 5-2C VI. PLAN IMPLEIENTATION 6-1 A. DIVISION OF PLAN...the possibility of flash flooding while residents sleep . 2. Historical Flood Damages The twin cities of Nogales, Arizona and Nogales, Sonora have a

A Novel Approach to Prediction of Mild Obstructive Sleep Disordered Breathing in a Population-Based Sample: The Sleep Heart Health Study

PubMed Central

Caffo, Brian; Diener-West, Marie; Punjabi, Naresh M.; Samet, Jonathan

2010-01-01

This manuscript considers a data-mining approach for the prediction of mild obstructive sleep disordered breathing, defined as an elevated respiratory disturbance index (RDI), in 5,530 participants in a community-based study, the Sleep Heart Health Study. The prediction algorithm was built using modern ensemble learning algorithms, boosting in specific, which allowed for assessing potential high-dimensional interactions between predictor variables or classifiers. To evaluate the performance of the algorithm, the data were split into training and validation sets for varying thresholds for predicting the probability of a high RDI (≥ 7 events per hour in the given results). Based on a moderate classification threshold from the boosting algorithm, the estimated post-test odds of a high RDI were 2.20 times higher than the pre-test odds given a positive test, while the corresponding post-test odds were decreased by 52% given a negative test (sensitivity and specificity of 0.66 and 0.70, respectively). In rank order, the following variables had the largest impact on prediction performance: neck circumference, body mass index, age, snoring frequency, waist circumference, and snoring loudness. Citation: Caffo B; Diener-West M; Punjabi NM; Samet J. A novel approach to prediction of mild obstructive sleep disordered breathing in a population-based sample: the Sleep Heart Health Study. SLEEP 2010;33(12):1641-1648. PMID:21120126

Sleep Problems, Comorbid Mental Disorders, and Role Functioning in the National Comorbidity Survey Replication (NCS-R)

PubMed Central

Roth, Thomas; Jaeger, Savina; Jin, Robert; Kalsekar, Anupama; Stang, Paul E.; Kessler, Ronald C.

2007-01-01

Background Little is known about the population prevalence of sleep problems or whether the associations of sleep problems with role impairment are due to comorbid mental disorders. Methods The associations of four 12-month sleep problems (difficulty initiating or maintaining sleep, early morning awakening, nonrestorative sleep) with role impairment were analyzed in the National Comorbidity Survey Replication controlling 12-month DSM-IV anxiety, mood, impulse-control, and substance disorders. The WHO Composite International Diagnostic Interview was used to assess sleep problems and DSM-IV disorders. The WHO Disability Schedule-II (WHO-DAS) was used to assess role impairment. Results Prevalence estimates of the separate sleep problems were in the range 16.4-25.0%, with 36.3% reporting at least one of the four. Mean 12-month duration was 24.4 weeks. All four problems were significantly comorbid with all the 12-month DMS-IV disorders assessed in the survey (median OR: 3.4; 25th-75th percentile: 2.8-3.9) and significantly related to role impairment. Relationships with role impairment generally remained significant after controlling comorbid mental disorders. Nonrestorative sleep was more strongly and consistently related to role impairment than were the other sleep problems. Conclusions The four sleep problems considered here are of public health significance because of their high prevalence and significant associations with role impairment. PMID:16952333

Registrar sleep patterns and supervision during two different rosters in a tertiary Australasian intensive care unit.

PubMed

Poynter, Chris J; Garden, Alexander; Young, Paul J

2012-03-01

To compare registrar sleep and supervision hours before and after a change in roster to accommodate more senior registrar (SR) positions, and to identify risky patterns of sleep on night shifts. Prospective study of 21 registrars on two different roster templates from September 2010 to May 2011 in the intensive care unit of Wellington Regional Hospital, Wellington, New Zealand. Roster change from 13 registrars and one SR to 10 registrars and four SRs. Mean sleep and supervision hours by shift; episodes of sleep ≤ 5 hours, wakefulness ≥17 hours, sleep during shift, waking before 16:00 before night shifts. 990 sleep surveys were analysed. There was no significant difference between groups in mean sleep or supervision hours for any shift. Two hundred and thirty-six night shifts were analysed. Registrars slept ≤5 hours before 19/236 (8.1%) night shifts; had ≥17 hours wakefulness before 79/236 night shifts (33.5%); woke by 16:00 107/ 236 (45.3%) times; and slept during 86/236 (36.4%) night shifts. Registrars arrived at work having either woken before 16:00 or had ≤5 hours of sleep on 114/236 (48.3%) night shifts. Changing the registrar roster to meet the training demands of our senior trainees did not adversely affect registrar sleep or supervision. Registrars may be taking on unnecessary risk due to poor sleep hygiene around night shifts. We suggest sleep education and scheduled sleep time during night shifts.

Sleep patterns and sleep-related complaints of Brazilian interstate bus drivers.

PubMed

Mello, M T; Santana, M G; Souza, L M; Oliveira, P C; Ventura, M L; Stampi, C; Tufik, S

2000-01-01

Sleep-related complaints have become a highlight for physicians as well as public health administrators. Studies of sleep patterns and sleep-related complaints of shift workers have been useful in minimizing reduction in the quality of life due to the warping of the sleep-wake cycle. The objective of the present study was to assess patterns of sleep, sleep-related complaints as well as physical activity and scoring rates for depression and anxiety in interstate bus drivers. Data were obtained with a sleep questionnaire, with the Beck inventory for depression, and the State-Trait Anxiety Inventory (STAI). A total of 400 interstate bus drivers from the northern, southern, central-western and south-eastern regions of Brazil were interviewed. Sixty percent of the subjects interviewed presented at least one sleep-related complaint, 16% admitted to have dozed at the wheel while on duty, and 41% stated that they exercised on a regular basis. Other sleep disturbance complaints reported were: sleep latency 29'17"; physical fatigue, 59.8%; mental fatigue, 45.4%; sleepiness, 25.8%; irritability, 20.6%; insomnia, 37.5%, respiratory disturbances, 19. 25% and snoring, 20.75%. Scores for anxiety and depression were not in the pathological range. The present data reinforce the view that bus drivers are generally discontent with shift work and its effects on sleep. Consequently, it is very important to establish an appropriate work schedule for drivers, besides implementing photo-therapy and physical activities in order to minimize sleepiness when driving.

Sleep patterns and predictors of disturbed sleep in a large population of college students.

PubMed

Lund, Hannah G; Reider, Brian D; Whiting, Annie B; Prichard, J Roxanne

2010-02-01

To characterize sleep patterns and predictors of poor sleep quality in a large population of college students. This study extends the 2006 National Sleep Foundation examination of sleep in early adolescence by examining sleep in older adolescents. One thousand one hundred twenty-five students aged 17 to 24 years from an urban Midwestern university completed a cross-sectional online survey about sleep habits that included the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, the Horne-Ostberg Morningness-Eveningness Scale, the Profile of Mood States, the Subjective Units of Distress Scale, and questions about academic performance, physical health, and psychoactive drug use. Students reported disturbed sleep; over 60% were categorized as poor-quality sleepers by the PSQI, bedtimes and risetimes were delayed during weekends, and students reported frequently taking prescription, over the counter, and recreational psychoactive drugs to alter sleep/wakefulness. Students classified as poor-quality sleepers reported significantly more problems with physical and psychological health than did good-quality sleepers. Students overwhelmingly stated that emotional and academic stress negatively impacted sleep. Multiple regression analyses revealed that tension and stress accounted for 24% of the variance in the PSQI score, whereas exercise, alcohol and caffeine consumption, and consistency of sleep schedule were not significant predictors of sleep quality. These results demonstrate that insufficient sleep and irregular sleep-wake patterns, which have been extensively documented in younger adolescents, are also present at alarming levels in the college student population. Given the close relationships between sleep quality and physical and mental health, intervention programs for sleep disturbance in this population should be considered. Copyright 2010 Society for Adolescent Medicine. Published by Elsevier Inc. All rights reserved.

The Impact of a Randomized Sleep Education Intervention for College Students.

PubMed

Hershner, Shelley; O'Brien, Louise M

2018-03-15

Sleep deprivation can impair attention, mood, and performance; however, few effective sleep education programs are available. The aim of this study was to assess the effect of a sleep education website, Sleep to Stay Awake (sleeptostayawake.org), on sleep behaviors of college students. College students (age 18 years or older) attending a public Midwestern university were randomized to control or intervention groups. All subjects completed baseline surveys that included demographics, Pittsburgh Sleep Quality Index, Patient Health Questionnaire, sleep knowledge, and measures of sleepiness and circadian rhythm. The intervention group then undertook the online intervention. Surveys were repeated at 1 week and at 8 weeks. Students who participated included 295 controls and 254 intervention subjects. The mean age was 21.9 ± 4.1 years and 41.7% were male. Survey results at 8 weeks showed that more intervention subjects reported improved sleep behaviors (50.3% versus 39.5%, P = .04). Intervention subjects were more likely to stop electronics use earlier (odds ratio [95% confidence interval] = 1.5 [1.0-2.4]), keep a more regular sleep schedule (1.6 [1.06-2.4]), have an earlier weekday rise time (2.4 [1.3-4.4]), and have a lower likelihood of insufficient sleep prior to examinations (0.46 [0.28-0.76]). The intervention group had improvement in mean sleep quality (odds ratio = 5.8 versus 6.6, P < .001) and depression scores (odds ratio = 4.6 versus 5.6, P = .03). No significant differences were found in the other measures. A brief and personalized online sleep education intervention improved sleep behaviors, sleep quality, and depressions scores. This novel approach to address sleep deprivation, poor sleep habits, and mood among college students may offer an effective and inexpensive remedy. © 2018 American Academy of Sleep Medicine.

Pilot study of a mindfulness-based, multi-component, in-school group sleep intervention in adolescent girls.

PubMed

Bei, Bei; Byrne, Michelle L; Ivens, Clare; Waloszek, Joanna; Woods, Michael J; Dudgeon, Paul; Murray, Greg; Nicholas, Christian L; Trinder, John; Allen, Nicholas B

2013-05-01

Existing literature links poor sleep and anxiety symptoms in adolescents. This pilot study aimed to develop a practical method through which a program to improve sleep could reach adolescents in need and to examine the feasibility of a mindfulness-based, multi-component group sleep intervention using sleep and anxiety as outcome measures. Sixty-two grade 9 students (aged 13-15) at a girls' school were screened with the Pittsburgh Sleep Quality Index (PSQI) and Spence Children's Anxiety Scale (SCAS). Ten participants with self-reported poor sleep were enrolled into a six-session program based on Bootzin & Stevens, with added stress/anxiety-specific components. Sessions covered key aspects of basic mindfulness concepts and practice, sleep hygiene, sleep scheduling, evening/daytime habits, stimulus control, skills for bedtime worries and healthy attitudes to sleep. Treatment changes were measured by pre-post scores on the PSQI, SCAS and 7-day actigraphy-measured sleep. The program demonstrated high acceptability, with a completion rate of 90%. Based on effect-size analysis, participants showed significant improvement on objective sleep onset latency (SOL), sleep efficiency and total sleep time; actigraphy data also showed significantly earlier bedtime, rise time and smaller day-to-day bedtime variation. Post-intervention global PSQI scores were significantly lower than that of pre-intervention, with significant improvement in subjective SOL, sleep quality and sleep-related daytime dysfunction. There were small improvements on some subscales of the SCAS, but change on its total score was minimal. A mindfulness-based, multi-component, in-school group sleep intervention following brief screening is feasible, and has the potential to improve sleep. Its impact on anxiety needs further investigation. © 2012 Wiley Publishing Asia Pty Ltd.

Sleep patterns and insomnia among portuguese adolescents: a cross-sectional study.

PubMed

Amaral, Odete; Garrido, António; Pereira, Carlos; Veiga, Nélio; Serpa, Carla; Sakellarides, Constantino

2014-11-01

Inadequate sleep patterns and insomnia are frequently linked and represent common sleep disorders among adolescents. The present study provides data on sleep patterns and insomnia among Portuguese adolescents. In a cross-sectional study we evaluated 6,919 students from the 7th to the 12th grade from twenty-six secondary schools. Data was collected using a self-administered questionnaire. Insomnia was defined based on the Diagnostic and Statistical Manual of Mental Disorders IV criteria and daytime sleepiness was assessed with the Epworth Sleepiness Scale. Sleep patterns evaluated both sleep duration ("insufficient" sleep was defined as < 8 hours per night) and bedtime schedules and regularity. The prevalence of insomnia was 8.3%, insomnia symptoms 21.4% and insufficient sleep 29.3%. All prevalence were higher among girls (P<.001). Average sleep time, on weeknights, was 8:04±1:13 hours. On average adolescents went to bed at 22:18±1:47 hours, took 21 minutes to fall asleep and woke up at 7:15±0:35 hours. Only 6.4% of adolescents stated having a regular bedtime. The majority of adolescents (90.6%) reported having difficulty waking up, 64.7% experienced daytime sleepiness and 53.3% experienced sleep during classes. There are high prevalence of inadequate sleep patterns, insufficient sleep and insomnia among Portuguese adolescents. Insufficient sleep is associated with sleep patterns and social and behavioural factors. These results add to our knowledge of adolescent sleep worldwide. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

The influence of school time on sleep patterns of children and adolescents.

PubMed

Carissimi, Alicia; Dresch, Fabiane; Martins, Alessandra Castro; Levandovski, Rosa Maria; Adan, Ana; Natale, Vincenzo; Martoni, Monica; Hidalgo, Maria Paz

2016-03-01

This epidemiological study evaluated the impact of school time on sleep parameters of children and adolescents. This cross-sectional study involved 639 elementary and high school students (mean age 13.03 years, range 8-18, 58.5% female) from the south of Brazil. Participants answered the Morningness-Eveningness Questionnaire (MEQ), and were asked about their sleeping habits on weekdays and weekends. Sleep deficit was defined as the difference between sleep duration on weekdays and weekends. The morning-school-time students presented significantly higher age, bedtime and wake up differences, sleep deficits, and social jetlag. The sleep deficit presented by girls was greater than that observed in boys of the same age. The difference between weekday and weekend waking times was also significantly greater in girls than in boys aged 13-18 years. Sleep deficit was significantly positively correlated with age and differences in wake up times, and significantly negatively correlated with MEQ scores, social jetlag, difference between weekday and weekend bedtimes, midpoint of sleep on weekends, and midpoint of sleep on weekends corrected for sleep deficit. A step-by-step multivariate logistic regression identified social jetlag, the difference between waking times on weekdays and weekends, and the midpoint of sleep on weekends as significant predictors of sleep deficit (Adjusted R(2) = 0.95; F = 1606.87; p <0.001). The results showed that school time influences the sleep parameters. The association of school schedules and physiological factors influence the sleep/wake cycle. Copyright © 2015 Elsevier B.V. All rights reserved.

A gender perspective on sleeplessness behavior, effects of sleep loss, and coping resources in patients with stable coronary artery disease.

PubMed

Edéll-Gustafsson, Ulla; Svanborg, Eva; Swahn, Eva

2006-01-01

The primary aim of this study was to systematically compare perceived sleep quality, sleeplessness behavior, sense of mastery, self-esteem, depression, subjective health, and effects of sleep loss in men and women with stable coronary artery disease (CAD). Further aims were to determine possible predictors of poor sleep quality and sense of mastery, as well as the consequences of too little sleep. Comparative-correlation and predictive design were used. Patients with a history of stable angina pectoris scheduled to undergo coronary angiography at Linköping University Hospital in Sweden were included. There were 47 women and 88 men (mean age 62.4 years) with CAD. Structured interviews using validated questionnaires covered sleep quality and sleep habits, effects of sleep loss, psychologic resources, and depression. Multiple stepwise regression analysis showed that sleeplessness behavior, depressed mood, female gender, and pharmacologic treatments with inflammation inhibitors significantly (P<.0001) accounted for the variance of poorer sleep quality. The analysis also showed that the following factors in descending order significantly accounted (P<.0001) for the outcome of sleep quality: inability to feel refreshed by sleep, difficulty in maintaining sleep, gastrointestinal problems, too little sleep, final morning awakening time, sleep onset latency, lying down because of daytime tiredness, and daytime physical tiredness. Compared with men, women with stable CAD may be especially at risk of experiencing poor sleep quality, even when sleeplessness behavior and pharmacologic treatments with inflammation inhibitors are controlled. It is also possible that they may be more at risk of depressed mood.

Actigraph measures of sleep among female hospital employees working day or alternating day and night shifts.

PubMed

Korsiak, Jill; Tranmer, Joan; Leung, Michael; Borghese, Michael M; Aronson, Kristan J

2017-07-14

Sleep disturbance is common among shift workers, and may be an important factor in the effect of shift work on chronic disease development. In this cross-sectional study, we described sleep patterns of 294 female hospital workers (142 alternating day-night shift workers, 152 day workers) and determined associations between shift work and sleep duration. Rest-activity cycles were recorded with the ActiGraph GT3X+ for 1 week. Analyses were stratified by chronotype of shift workers. Using all study days to calculate average sleep duration, shift workers slept approximately 13 min less than day workers during main sleep periods, while 24-h sleep duration did not differ between day workers and shift workers. Results from age-adjusted models demonstrated that all shift workers, regardless of chronotype, slept 20-30 min less than day workers on day shifts during main and total sleep. Early and intermediate chronotypes working night shifts slept between 114 and 125 min less than day workers, both with regard to the main sleep episode and 24-h sleep duration, while the difference was less pronounced among late chronotypes. When sleep duration on free days was compared between shift workers and day workers, only shift workers with late chronotypes slept less, by approximately 50 min, than day workers during main sleep. Results from this study demonstrate how an alternating day-night shift work schedule impacts sleep negatively among female hospital workers, and the importance of considering chronotype in sleep research among shift workers. © 2017 European Sleep Research Society.

Effect of the first night shift period on sleep in young nurse students.

PubMed

Fietze, Ingo; Knoop, Karsten; Glos, Martin; Holzhausen, Martin; Peter, Jan Giso; Penzel, Thomas

2009-12-01

In young hospital nurses being exposed to a night shift work schedule for the first time in their occupational life, sleep quality is investigated quantitatively. A main sleep period and supplementary sleep periods were defined and analyzed to investigate sleep behavior and quality. A total of 30 young nurses (26 women, 4 men), mean age 20.2 +/- 2.1 years participated. A 3 week nursing school period was followed by a 3 week work period with a 3-5 night shift sub-period and recovery days. Sleep-wake behavior was assessed with an actigraph, sleep diaries, Epworth sleepiness scale (ESS), and quality of life was assessed with a standard questionnaire (SF-36). Comparing the school period with the work shift period when excluding recovery days after night shift period significant increase of total sleep time within 24 h was found during the work days (ANOVA P < 0.05). During the night shift sub-period, there was just a small decline of the main sleep period at day (n.s.) which was not compensated by supplementary sleep episodes. The supplementary sleep during work day varied between 11 min (school period) and 18 min after recovery days from night shift (n.s.). Young healthy nurses tolerate the first night shift exposure very well, according to objective and subjective parameters related to quality of sleep. An increased sleep need during work days lead to longer total sleep time, but do not lead to longer supplementary sleep episodes. Young nurses tolerate the first rotating shift period and the first night shift period very well.

Do Circadian Preferences Influence the Sleep Patterns of Night Shift Drivers?

PubMed Central

Narciso, Fernanda V.; Esteves, Andrea M.; Oliveira e Silva, Luciana; Bittencourt, Lia R.A.; Silva, Rogerio S.; Pires, Maria Laura N.; Tufik, Sergio; de Mello, Marco Tulio

2013-01-01

Objective The objective of this study was to analyze the effect of individual circadian preferences of drivers with fixed night work schedules on sleep patterns. Subjects and Methods A total of 123 professional drivers, 32 indifferent preference drivers and 91 morning preference drivers of an intermunicipality and interstate bus transportation company were evaluated. All drivers underwent polysomnographic recordings after their shifts. Furthermore, they filled out a questionnaire that contained sociodemographic and health questions. The Horne and Östberg questionnaire was used to assess the subjects' morningness-eveningness preference. Results The mean age was 42.54 ± 6.98 years and 82 (66.66%) of the drivers had worked for ≥15 years. A significant effect on rapid eye movement (REM) was observed in the morning preference drivers. They showed an increased sleep latency and an REM sleep percentage of 5% of the total REM time. This reveals a significant effect on sleep architecture associated with work time. Conclusion The drivers reported that morning preference had a significant effect on their sleep pattern indicating less REM sleep and longer REM sleep latency in the morning preference group. Thus, it is important to evaluate interactions between individual aspects of health and other parameters, such as sleep quality and work organizational factors, to promote night shift workers' health and well-being. PMID:23988815

Pilot fatigue survey: exploring fatigue factors in air medical operations.

PubMed

Gregory, Kevin B; Winn, William; Johnson, Kent; Rosekind, Mark R

2010-01-01

Humans confront significant physiological challenges with sleep and alertness when working in 24/7 operations. A web-based national survey of air medical pilots examined issues relevant to fatigue and sleep management. Six hundred ninety-seven responses were received, with a majority of rotor wing pilots working 3/3/7 and 7/7 duty schedules. Over 84% of the pilots reported that fatigue had affected their flight performance; less than 28% reported "nodding off" during flight. More than 90% reported a separate work site "rest" room with a bed available. Over 90% reported no company policies restricting on-duty sleep. Approximately half of the pilots reported getting 4 hours or more sleep during a typical night shift. Approximately half reported that sleep inertia had never compromised flight safety. Over 90% reported that it was better to sleep during the night and overcome sleep inertia if necessary. Survey results reflected practices that can mitigate the degrading effects of fatigue, including the availability of designated work-site sleep rooms. As demands continue to evolve, the need remains for sustained efforts to address fatigue-related risks in the air medical transport industry. This includes further study of sleep inertia issues and the need for alertness management programs. Copyright © 2010 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

Circadian Misalignment Augments Markers of Insulin Resistance and Inflammation, Independently of Sleep Loss

PubMed Central

Leproult, Rachel; Holmbäck, Ulf; Van Cauter, Eve

2014-01-01

Shift workers, who are exposed to irregular sleep schedules resulting in sleep deprivation and misalignment of circadian rhythms, have an increased risk of diabetes relative to day workers. In healthy adults, sleep restriction without circadian misalignment promotes insulin resistance. To determine whether the misalignment of circadian rhythms that typically occurs in shift work involves intrinsic adverse metabolic effects independently of sleep loss, a parallel group design was used to study 26 healthy adults. Both interventions involved 3 inpatient days with 10-h bedtimes, followed by 8 inpatient days of sleep restriction to 5 h with fixed nocturnal bedtimes (circadian alignment) or with bedtimes delayed by 8.5 h on 4 of the 8 days (circadian misalignment). Daily total sleep time (SD) during the intervention was nearly identical in the aligned and misaligned conditions (4 h 48 min [5 min] vs. 4 h 45 min [6 min]). In both groups, insulin sensitivity (SI) significantly decreased after sleep restriction, without a compensatory increase in insulin secretion, and inflammation increased. In male participants exposed to circadian misalignment, the reduction in SI and the increase in inflammation both doubled compared with those who maintained regular nocturnal bedtimes. Circadian misalignment that occurs in shift work may increase diabetes risk and inflammation, independently of sleep loss. PMID:24458353

Do circadian preferences influence the sleep patterns of night shift drivers?

PubMed

Narciso, Fernanda V; Esteves, Andrea M; Oliveira e Silva, Luciana; Bittencourt, Lia R A; Silva, Rogerio S; Pires, Maria Laura N; Tufik, Sergio; de Mello, Marco Tulio

2013-01-01

The objective of this study was to analyze the effect of individual circadian preferences of drivers with fixed night work schedules on sleep patterns. A total of 123 professional drivers, 32 indifferent preference drivers and 91 morning preference drivers of an intermunicipality and interstate bus transportation company were evaluated. All drivers underwent polysomnographic recordings after their shifts. Furthermore, they filled out a questionnaire that contained sociodemographic and health questions. The Horne and Östberg questionnaire was used to assess the subjects' morningness-eveningness preference. The mean age was 42.54 ± 6.98 years and 82 (66.66%) of the drivers had worked for ≥15 years. A significant effect on rapid eye movement (REM) was observed in the morning preference drivers. They showed an increased sleep latency and an REM sleep percentage of 5% of the total REM time. This reveals a significant effect on sleep architecture associated with work time. The drivers reported that morning preference had a significant effect on their sleep pattern indicating less REM sleep and longer REM sleep latency in the morning preference group. Thus, it is important to evaluate interactions between individual aspects of health and other parameters, such as sleep quality and work organizational factors, to promote night shift workers' health and well-being. © 2013 S. Karger AG, Basel.

Need for recovery from work and sleep-related complaints among nursing professionals.

PubMed

Silva-Costa, Aline; Griep, Rosane Harter; Fischer, Frida Marina; Rotenberg, Lúcia

2012-01-01

The concept of need for recovery from work (NFR) was deduced from the effort recuperation model. In this model work produces costs in terms of effort during the working day. When there is enough time and possibilities to recuperate, a worker will arrive at the next working day with no residual symptoms of previous effort. NFR evaluates work characteristics such as psychosocial demands, professional work hours or schedules. However, sleep may be an important part of the recovery process. The aim of the study was to test the association between sleep-related complaints and NFR. A cross-sectional study was carried out at three hospitals. All females nursing professionals engaged in assistance to patients were invited to participate (N = 1,307). Participants answered a questionnaire that included four sleep-related complaints (insomnia, unsatisfactory sleep, sleepiness during work hours and insufficient sleep), work characteristics and NRF scale. Binomial logistic regression analysis showed that all sleep-related complaints are associated with a high need for recovery from work. Those who reported insufficient sleep showed a greater chance of high need for recovery; OR=2.730 (CI 95% 2.074 - 3.593). These results corroborate the hypothesis that sleep is an important aspect of the recovery process and, therefore, should be thoroughly investigated.

Clusters of Insomnia Disorder: An Exploratory Cluster Analysis of Objective Sleep Parameters Reveals Differences in Neurocognitive Functioning, Quantitative EEG, and Heart Rate Variability.

PubMed

Miller, Christopher B; Bartlett, Delwyn J; Mullins, Anna E; Dodds, Kirsty L; Gordon, Christopher J; Kyle, Simon D; Kim, Jong Won; D'Rozario, Angela L; Lee, Rico S C; Comas, Maria; Marshall, Nathaniel S; Yee, Brendon J; Espie, Colin A; Grunstein, Ronald R

2016-11-01

To empirically derive and evaluate potential clusters of Insomnia Disorder through cluster analysis from polysomnography (PSG). We hypothesized that clusters would differ on neurocognitive performance, sleep-onset measures of quantitative ( q )-EEG and heart rate variability (HRV). Research volunteers with Insomnia Disorder (DSM-5) completed a neurocognitive assessment and overnight PSG measures of total sleep time (TST), wake time after sleep onset (WASO), and sleep onset latency (SOL) were used to determine clusters. From 96 volunteers with Insomnia Disorder, cluster analysis derived at least two clusters from objective sleep parameters: Insomnia with normal objective sleep duration (I-NSD: n = 53) and Insomnia with short sleep duration (I-SSD: n = 43). At sleep onset, differences in HRV between I-NSD and I-SSD clusters suggest attenuated parasympathetic activity in I-SSD (P < 0.05). Preliminary work suggested three clusters by retaining the I-NSD and splitting the I-SSD cluster into two: I-SSD A (n = 29): defined by high WASO and I-SSD B (n = 14): a second I-SSD cluster with high SOL and medium WASO. The I-SSD B cluster performed worse than I-SSD A and I-NSD for sustained attention (P ≤ 0.05). In an exploratory analysis, q -EEG revealed reduced spectral power also in I-SSD B before (Delta, Alpha, Beta-1) and after sleep-onset (Beta-2) compared to I-SSD A and I-NSD (P ≤ 0.05). Two insomnia clusters derived from cluster analysis differ in sleep onset HRV. Preliminary data suggest evidence for three clusters in insomnia with differences for sustained attention and sleep-onset q -EEG. Insomnia 100 sleep study: Australia New Zealand Clinical Trials Registry (ANZCTR) identification number 12612000049875. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=347742. © 2016 Associated Professional Sleep Societies, LLC.

Daily hunger sensation monitoring as a tool for investigating human circadian synchronization.

PubMed

Cugini, P; Camillieri, G; Alessio, L; Cristina, G; De Rosa, R; Petrangeli, C M

2000-03-01

This study investigates within-day hunger sensation (HS) variability in Clinically Healthy Subjects Adapted to Living in Antarctica (CHSALA), as compared to their coeval subjects living in their mother country. The aim is to detect how the orectic stimulus behaves in those environmental conditions and occupational schemes, in order to investigate the individual synchronization to sleep-wake alternation and meal time schedule. HS was estimated via a self-rating score of its intensity on a Visual Analog Scale, repeating the subjective perception every 30 min, unless sleeping. The individual HS time-qualified scores (orexigram) were analyzed according to conventional and chronobiological procedures. The orexigrams of the CHSALA were seen to show a more cadenced intermittence during the diurnal part of the day, strictly related to the meal timing, and a preserved circadian rhythm as well. In addition, these orexigrams were resolved in a spectrum of harmonic components which indicated a subsidiary number of ultradian formants. These findings are convincing evidence that the individual orexigram may be used to investigate whether or not a single subject is synchronized to sleep-wake cycle, meal time schedule and socio-occupational routines, instead of using more complex and expensive techniques, involving automated equipments and biohumoral assays.

Medication Use by U.S. Crewmembers on the International Space Station

NASA Technical Reports Server (NTRS)

Wotring, V. E.

2015-01-01

This study examined medication use during long-duration. Medication records from 24 crewmembers on 20 missions (greater than 30 days duration) were examined for trends in usage rates, efficacy, indication, as well as adverse event qualities, frequencies and severities. No controls were possible in this observational, retrospective analysis of available data; comparisons are made to similar studies of individuals on shortduration spaceflights and submarine deployments. The most frequently used medications were for sleep problems, pain, congestion or allergy. Medication use during spaceflight missions was similar to what is seen in adult ambulatory medicine; one notable exception is that usage of sleep aids was about 10 times higher in spaceflight. There were also two apparent treatment failures in cases of skin rash, raising questions about the efficacy or suitability of the treatments used. Many spaceflight-related medication uses were linked to extravehicular-activities and operationally-driven schedule changes. The data suggest that sleep and skin rash merit additional study prior to longer space exploration missions. It also seems likely that alterations in schedule-shifting or extravehicular activity suits would reduce the need for many medication uses, preserving resources as well as improving crew quality of life.

Napping on the Night Shift: A Study of Sleep, Performance, and Learning in Physicians-in-Training

PubMed Central

McDonald, Jennifer; Potyk, Darryl; Fischer, David; Parmenter, Brett; Lillis, Teresa; Tompkins, Lindsey; Bowen, Angela; Grant, Devon; Lamp, Amanda; Belenky, Gregory

2013-01-01

Background Physicians in training experience fatigue from sleep loss, high workload, and working at an adverse phase of the circadian rhythm, which collectively degrades task performance and the ability to learn and remember. To minimize fatigue and sustain performance, learning, and memory, humans generally need 7 to 8 hours of sleep in every 24-hour period. Methods In a naturalistic, within-subjects design, we studied 17 first- and second-year internal medicine residents working in a tertiary care medical center, rotating between day shift and night float every 4 weeks. We studied each resident for 2 weeks while he/she worked the day shift and for 2 weeks while he/she worked the night float, objectively measuring sleep by wrist actigraphy, vigilance by the Psychomotor Vigilance Task test, and visual-spatial and verbal learning and memory by the Brief Visuospatial Memory Test-Revised and the Rey Auditory-Verbal Learning Test. Results Residents, whether working day shift or night float, slept approximately 7 hours in every 24-hour period. Residents, when working day shift, consolidated their sleep into 1 main sleep period at night. Residents working night float split their sleep, supplementing their truncated daytime sleep with nighttime on-duty naps. There was no difference in vigilance or learning and memory, whether residents worked day shift or night float. Conclusions Off-duty sleep supplemented with naps while on duty appears to be an effective strategy for sustaining vigilance, learning, and memory when working night float. PMID:24455014

Sleep Patterns Are Associated with Common Illness in Adolescents

PubMed Central

Orzech, Kathryn M.; Acebo, Christine; Seifer, Ronald; Barker, David; Carskadon, Mary A.

2014-01-01

Summary This prospective, field-based study examined the association between actigraphically-measured total sleep time and incident illness including cold, flu, gastroenteritis, and other common infectious diseases (e.g., strep throat) in adolescents over the course of a school semester. Participants were 56 adolescents ages 14–19 years (mean = 16.6 (standard deviation = 1.2), 39% male) from 5 high schools in Rhode Island. Beginning in late January, adolescents wore actigraphs (mean 91 (19) days, range 16 – 112 days) and were assigned post-hoc to Longer or Shorter sleep groups based on median splits. Adolescents were interviewed weekly across as many as 16 weeks (modal number of interviews = 13) using a structured protocol that included 14 health event questions. Illness events and illness-related school absences were coded for 710 completed interviews, with 681 illness events and 90 school absences reported. Outcomes (illness bouts, illness duration, and absences) were compared among sex, sleep, and academic year groups using non-parametric regression. In a subset of 18 subjects, mean actigraphically estimated total sleep time 6 nights before matched illness/wellness events was compared using MANOVA. Longer sleepers and males reported fewer illness bouts; total sleep time effects were more apparent in males than females. A trend was found for shorter total sleep time before ill events. The present findings in this small naturalistic sample indicate that acute illnesses were more frequent in otherwise healthy adolescents with shorter sleep, and illness events were associated with less sleep during the prior week than comparable matched periods without illness. PMID:24134661

Sleep Problems and Their Relationship to Maladaptive Behavior Severity in Psychiatrically Hospitalized Children with Autism Spectrum Disorder (ASD).

PubMed

Sannar, Elise M; Palka, Tamara; Beresford, Carol; Peura, Christine; Kaplan, Desmond; Verdi, Mary; Siegel, Matthew; Kaplan, Shir; Grados, Marco

2017-10-30

We examined the relationship between sleep duration and awakenings to Aberrant Behavior Checklist-Community (ABC-C) and Autism Diagnostic Observation Schedule (ADOS-2) scores in hospitalized youth with ASD and behavioral disturbance. Participants included 106 patients with a stay of at least 10 nights. Sleep in the hospital was recorded by staff observation. Higher scores on the ABC-C (irritability, stereotypy, and hyperactivity subscales) at admission were significantly associated with fewer minutes slept during the last five nights of hospitalization. There was no association between total awakenings and ABC-C scores or ADOS-2 comparison scores. Improved understanding of the relationship between sleep quality and maladaptive behavior in this challenging cohort of patients with ASD is vital to the definition and design of future effective interventions.

Sleep Strategies of Night-Shift Nurses on Days Off: Which Ones are Most Adaptive?

PubMed Central

Petrov, Megan E.; Clark, C. Brendan; Molzof, Hylton E.; Johnson, Russell L.; Cropsey, Karen L.; Gamble, Karen L.

2014-01-01

Objectives: To determine the off-shift sleep strategies of bi-ethnic night-shift nurses, the relationship between these sleep strategies and adaptation to shift work, and identify the participant-level characteristics associated with a given sleep strategy. Methods: African-American and non-Hispanic White female, night-shift nurses from an academic hospital were recruited to complete a survey on sleep–wake patterns (n = 213). Participants completed the standard shiftwork index and the biological clocks questionnaire to determine sleep strategies and adaptation to night-shift work. In addition, chronotype was determined quantitatively with a modified version of the Munich ChronoType Questionnaire. Most participants worked ~3 consecutive 12-h night-shifts followed by several days off. Results: Five sleep strategies used on days off were identified: (a) night stay, (b) nap proxy, (c) switch sleeper, (d) no sleep, and (e) incomplete switcher. Nap proxy and no sleep types were associated with poorer adaptation to night-shift work. The switch sleeper and incomplete switcher types were identified as more adaptive strategies that were associated with less sleep disturbance, a later chronotype, and less cardiovascular problems. Conclusion: Behavioral sleep strategies are related to adaptation to a typical night-shift schedule among hospital nurses. Nurses are crucial to the safety and well-being of their patients. Therefore, adoption of more adaptive sleep strategies may reduce sleep/wake dysregulation in this population, and improve cardiovascular outcomes. PMID:25566182

Short sleep duration and irregular bedtime are associated with increased behavioral problems among Japanese preschool-age children.

PubMed

Komada, Yoko; Abe, Takashi; Okajima, Isa; Asaoka, Shoichi; Matsuura, Noriko; Usui, Akira; Shirakawa, Shuichiro; Inoue, Yuichi

2011-06-01

Sleep problems are known to be risk factors for subsequent emotional and behavioral difficulties in childhood and adolescence. To date, there has been no study investigating the relationships between sleep habits and behavioral problems in a large nonclinical sample of preschool age children. The aim of this study was to examine these relationships and factors associated with the sleep habits of preschool age (2 to 5 year old) children. Their mothers (n = 1,746) completed a multiple-choice questionnaire about the sleep habits and behavior problems of their children, as well as their own sleep habits and working hours at Tokyo metropolitan public nursery schools. The short sleep duration group showed significantly higher aggressive scores than the long sleep duration group among 2- to 3-year-old children, and the irregular bedtime group showed significantly higher aggressive and attention problem scores than the regular bedtime group among 4- to 5-year-old children. Univariate and multivariate logistic regression analyses revealed that children's late bedtime was associated with their mother's late waking-up time, and late schedule of both the mother's leaving and returning home. This study recognized an association between behavioral problems and poor sleep habits among preschool-age children. It is important for children to sleep regularly and adequately in order to decrease their behavior problems. In conclusion, appropriate management of children's sleep by their mothers is necessary for promoting sleep-related health of children.

The Circadian System Contributes to Apnea Lengthening across the Night in Obstructive Sleep Apnea.

PubMed

Butler, Matthew P; Smales, Carolina; Wu, Huijuan; Hussain, Mohammad V; Mohamed, Yusef A; Morimoto, Miki; Shea, Steven A

2015-11-01

To test the hypothesis that respiratory event duration exhibits an endogenous circadian rhythm. Within-subject and between-subjects. Inpatient intensive physiologic monitoring unit at the Brigham and Women's Hospital. Seven subjects with moderate/severe sleep apnea and four controls, age 48 (SD = 12) years, 7 males. Subjects completed a 5-day inpatient protocol in dim light. Polysomnography was recorded during an initial control 8-h night scheduled at the usual sleep time, then through 10 recurrent cycles of 2 h 40 min sleep and 2 h 40 min wake evenly distributed across all circadian phases, and finally during another 8-h control sleep period. Event durations, desaturations, and apnea-hypopnea index for each sleep opportunity were assessed according to circadian phase (derived from salivary melatonin), time into sleep, and sleep stage. Average respiratory event durations in NREM sleep significantly lengthened across both control nights (21.9 to 28.2 sec and 23.7 to 30.2 sec, respectively). During the circadian protocol, event duration in NREM increased across the circadian phases that corresponded to the usual sleep period, accounting for > 50% of the increase across normal 8-h control nights. AHI and desaturations were also rhythmic: AHI was highest in the biological day while desaturations were greatest in the biological night. The endogenous circadian system plays an important role in the prolongation of respiratory events across the night, and might provide a novel therapeutic target for modulating sleep apnea. © 2015 Associated Professional Sleep Societies, LLC.

Impact of insufficient sleep on total daily energy expenditure, food intake, and weight gain.

PubMed

Markwald, Rachel R; Melanson, Edward L; Smith, Mark R; Higgins, Janine; Perreault, Leigh; Eckel, Robert H; Wright, Kenneth P

2013-04-02

Insufficient sleep is associated with obesity, yet little is known about how repeated nights of insufficient sleep influence energy expenditure and balance. We studied 16 adults in a 14- to 15-d-long inpatient study and quantified effects of 5 d of insufficient sleep, equivalent to a work week, on energy expenditure and energy intake compared with adequate sleep. We found that insufficient sleep increased total daily energy expenditure by ∼5%; however, energy intake--especially at night after dinner--was in excess of energy needed to maintain energy balance. Insufficient sleep led to 0.82 ± 0.47 kg (±SD) weight gain despite changes in hunger and satiety hormones ghrelin and leptin, and peptide YY, which signaled excess energy stores. Insufficient sleep delayed circadian melatonin phase and also led to an earlier circadian phase of wake time. Sex differences showed women, not men, maintained weight during adequate sleep, whereas insufficient sleep reduced dietary restraint and led to weight gain in women. Our findings suggest that increased food intake during insufficient sleep is a physiological adaptation to provide energy needed to sustain additional wakefulness; yet when food is easily accessible, intake surpasses that needed. We also found that transitioning from an insufficient to adequate/recovery sleep schedule decreased energy intake, especially of fats and carbohydrates, and led to -0.03 ± 0.50 kg weight loss. These findings provide evidence that sleep plays a key role in energy metabolism. Importantly, they demonstrate physiological and behavioral mechanisms by which insufficient sleep may contribute to overweight and obesity.

Epidemiological aspects of self-reported sleep onset latency in Japanese junior high school children.

PubMed

Alexandru, Gaina; Michikazu, Sekine; Shimako, Hamanishi; Xiaoli, Chen; Hitomi, Kanayama; Takashi, Yamagami; Robert, Williams W; Sadanobu, Kagamimori

2006-09-01

The purpose of this study was to investigate the relationships between sleep onset latency (SOL) and other sleep-wake patterns and media use habits in Japanese schoolchildren. A total of 9,718 junior high school children responded (12.8 years) and 9199 questionnaires were used in the present analyses. The questionnaire assessed sleep-wake patterns, TV viewing and videogame habits. Overall, 72.1% of the subjects reported short SOL (20 min) were strongly associated with disturbed sleep manifested especially by increased risk of night awakenings, decreased sleep depth, and bad sleep in general (overall sleep quality). Prolonged SOL was also associated with daytime sleepiness, difficulties in falling asleep, bad morning feeling and sleep insufficiency. We found a U-shaped relationship between sleep period and SOL. Increase in bedtime was accompanied by increased risk of prolonged SOL. The impact of ultra-short and ultra-long SOL (or=40 min) was also analysed. Long durations of watching television and playing videogame were significantly associated with prolonged SOL. After adjustment for sex, girls presented significantly higher risk of prolonged SOL. Body mass index adjustment did not reveal any significant results. SOL presents a significant component of sleep-wake habits; poor sleep hygiene and insufficient sleep time significantly increase SOL. Parents, healthcare practitioners and children themselves should be aware of the potentially negative influence of prolonged SOL. Additionally, the optimal coherent sleep-wake schedule must be promoted in parallel with the limitation on the viewing TV and game practices.

Sleep habits in adolescents of Saudi Arabia; distinct patterns and extreme sleep schedules.

PubMed

Merdad, Roah A; Merdad, Leena A; Nassif, Rawan A; El-Derwi, Douaa; Wali, Siraj O

2014-11-01

There is a need for comprehensive studies on adolescents' sleep habits in the Middle Eastern region. The aim of this study was to investigate the sleep-wake patterns, prevalence of excessive daytime sleepiness (EDS), and disturbed sleep among adolescents in Saudi Arabia and to identify the associated factors. The study was a cross-sectional survey done on a random sample of 1035 high school students, ages 14-23 years, in Jeddah, Saudi Arabia. The response rate was 91%. Students filled a self-reported questionnaire that included sleep-wake questions, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Perceived Stress Scale, academic performance, and personal data. Students slept an average of 7.0 hours on school nights, with an average delay of 2.8 and 6.0 hours in weekend sleep and rise times, respectively. Around 1 in 10 students stayed up all night and slept after returning from school (exhibiting a reversed sleep cycle) on weeknights. This pattern was more prevalent among boys and students with lower grade point averages. The prevalence of sleep disturbance was 65%, and EDS was found in 37% of the students. Predictors of EDS were school type, stress, napping and caffeine use, while gender was a predictor of disturbed sleep. Adolescents in Saudi Arabia showed a high percentage of poor sleep quality. Compared with adolescents from other countries, they had a larger delay in weekend sleep and rise times. An alarming reversed sleep cycle on weekdays is present and highlights the need for further assessment. Copyright © 2014 Elsevier B.V. All rights reserved.

Sleep/Wake Patterns and Parental Perceptions of Sleep in Children Born Preterm

PubMed Central

Biggs, Sarah N.; Meltzer, Lisa J.; Tapia, Ignacio E.; Traylor, Joel; Nixon, Gillian M.; Horne, Rosemary S.C.; Doyle, Lex W.; Asztalos, Elizabeth; Mindell, Jodi A.; Marcus, Carole L.

2016-01-01

Study Objectives: To compare sleep/wake patterns in children born preterm in Australia vs Canada and determine cultural differences in the relationship between parental perception of sleep and actual sleep behaviors. Methods: Australian and Canadian children born preterm were recruited from the Caffeine for Apnea of Prematurity trial (n = 188, 5–12 y) and underwent 14 days actigraphy monitoring. Parents completed the National Sleep Foundation 2004 Sleep in America questionnaire. Cross-cultural differences in sleep characteristics assessed by actigraphy and parent-reported questionnaire were examined. Correlational analyses determined the associations between parental perceptions of child sleep need and sleep behavior. Results: Actigraphy showed preterm children obtained, on average, 8 h sleep/night, one hour less than population recommendations for their age. There was no difference in total sleep time (TST) between Australian and Canadian cohorts; however, bed and wake times were earlier in Australian children. Bedtimes and TST varied by 60 minutes from night to night in both cohorts. Parent-reported child TST on the National Sleep Foundation questionnaire was 90 minutes longer than recorded by actigraphy. Both bedtime and TST on weekdays and weekends were related to parental perception of child sleep need in the Australian cohort. Only TST on weekdays was related to parental perception of child sleep need in the Canadian cohort. Conclusions: This study suggests that short sleep duration and irregular sleep schedules are common in children born preterm. Cultural differences in the association between parental perception of child sleep need and actual sleep behaviors provide important targets for future sleep health education. Citation: Biggs SN, Meltzer LJ, Tapia IE, Traylor J, Nixon GM, Horne RS, Doyle LW, Asztalos E, Mindell JA, Marcus CL. Sleep/wake patterns and parental perceptions of sleep in children born preterm. J Clin Sleep Med 2016;12(5):711–717. PMID:26857057

Sleep Quality Estimation based on Chaos Analysis for Heart Rate Variability

NASA Astrophysics Data System (ADS)

Fukuda, Toshio; Wakuda, Yuki; Hasegawa, Yasuhisa; Arai, Fumihito; Kawaguchi, Mitsuo; Noda, Akiko

In this paper, we propose an algorithm to estimate sleep quality based on a heart rate variability using chaos analysis. Polysomnography(PSG) is a conventional and reliable system to diagnose sleep disorder and to evaluate its severity and therapeatic effect, by estimating sleep quality based on multiple channels. However, a recording process requires a lot of time and a controlled environment for measurement and then an analyzing process of PSG data is hard work because the huge sensed data should be manually evaluated. On the other hand, it is focused that some people make a mistake or cause an accident due to lost of regular sleep and of homeostasis these days. Therefore a simple home system for checking own sleep is required and then the estimation algorithm for the system should be developed. Therefore we propose an algorithm to estimate sleep quality based only on a heart rate variability which can be measured by a simple sensor such as a pressure sensor and an infrared sensor in an uncontrolled environment, by experimentally finding the relationship between chaos indices and sleep quality. The system including the estimation algorithm can inform patterns and quality of own daily sleep to a user, and then the user can previously arranges his life schedule, pays more attention based on sleep results and consult with a doctor.

[Sleep habits of medical students, physicians and nurses regarding age, sex, shift work and caffein consumption].

PubMed

Pecotić, Renata; Valić, Maja; Kardum, Goran; Sevo, Vana; Dogas, Zoran

2008-01-01

The aim of this study was to evaluate sleep habits of nurses, medical students, and physicians and to explore whether they are influenced by age, sex, shift work, and caffeine consumption. The questionnaire was derived from the MEDSleep Survey. A total of 453 respondents were surveyed: second-year medical students (130); physicians at the postgraduate study program (68); specialists (162); nurses (93). Results of our study indicate that hours of sleep needed for feeling rested depends on age and gender. Younger respondents and women in the study need longer sleep to feel rested (7.5 hours and more) than older ones and males who need less than 7.5 hours of sleep. Among medical professionals a need for sleep differs related to work demands and work schedule. Nurses need more sleep than physicians (chi2 = 38.57, p < 0.001). Female nurses need more sleep for feeling rested than female physicians (chi2 = 18.18, p < 0.001), and sleep longer during the weeknights (chi2 = 33.78, p < 0.001) and weekends (chi2 = 28.06, p < 0.001). The respondents that consume caffeine have more trouble staying awake while listening to lectures or learning (chi2 = 9.37, p = 0.009), and while driving a car (chi2 = 14.56, p = 0.001). The results indicate that sleep habits are related to age, sex and caffeine consumption.

Technology Use and Sleep Quality in Preadolescence and Adolescence.

PubMed

Bruni, Oliviero; Sette, Stefania; Fontanesi, Lilybeth; Baiocco, Roberto; Laghi, Fiorenzo; Baumgartner, Emma

2015-12-15

The purpose of this study was to analyze differences between preadolescents and adolescents on the use of technology and to test the contribution of using Internet and mobile phone, and circadian preference on sleep quality. We recruited a sample of 850 (364 males) preadolescents and adolescents. Self-report questionnaires about sleep schedule, sleep wake behavior problems, circadian preferences, and the use of technology (e.g., Internet and mobile phone) were administered. Students were asked to fill out the School Sleep Habits Survey, a self-report questionnaire on the use of technology, the Mobile Phone Involvement Questionnaire (MPIQ), and the Shorter Promis Questionnaire (SPQ). Adolescents reported more sleep problems, a tendency toward eveningness, and an increase of Internet and phone activities, as well as social network activities, while preadolescents were more involved in gaming console and television viewing. The regression analysis performed separately in the two age groups showed that sleep quality was affected by the circadian preference (eveningness) in both groups. Adolescents' bad sleep quality was consistently associated with the mobile phone use and number of devices in the bedroom, while in preadolescents, with Internet use and turning-off time. The evening circadian preference, mobile phone and Internet use, numbers of other activities after 21:00, late turning off time, and number of devices in the bedroom have different negative influence on sleep quality in preadolescents and adolescents. © 2015 American Academy of Sleep Medicine.

Does the Circadian Modulation of Dream Recall Modify with Age?

PubMed Central

Chellappa, Sarah Laxhmi; Münch, Mirjam; Blatter, Katharina; Knoblauch, Vera; Cajochen, Christian

2009-01-01

Study objectives: The ultradian NREM-REM sleep cycle and the circadian modulation of REM sleep sum to generate dreaming. Here we investigated age-related changes in dream recall, number of dreams, and emotional domain characteristics of dreaming during both NREM and REM sleep. Design: Analysis of dream recall and sleep EEG (NREM/REM sleep) during a 40-h multiple nap protocol (150 min of wakefulness and 75 min of sleep) under constant routine conditions. Setting: Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland. Participants: Seventeen young (20-31 years) and 15 older (57-74 years) healthy volunteers Interventions: N/A. Measurements and Results: Dream recall and number of dreams varied significantly across the circadian cycle and between age groups, with older subjects exhibiting fewer dreams (P < 0.05), particularly after naps scheduled during the biological day, closely associated with the circadian rhythm of REM sleep. No significant age differences were observed for the emotional domain of dream content. Conclusions: Since aging was associated with attenuated amplitude in the circadian modulation of REM sleep, our data suggest that the age-related decrease in dream recall can result from an attenuated circadian modulation of REM sleep. Citation: Chellappa SL; Möunch M; Blatter K; Knoblauch V; Cajochen C. Does the circadian modulation of dream recall modify with age? SLEEP 2009;32(9):1201-1209. PMID:19750925

Prevalence of sleep deficiency and use of hypnotic drugs in astronauts before, during, and after spaceflight: an observational study.

PubMed

Barger, Laura K; Flynn-Evans, Erin E; Kubey, Alan; Walsh, Lorcan; Ronda, Joseph M; Wang, Wei; Wright, Kenneth P; Czeisler, Charles A

2014-09-01

Sleep deprivation and fatigue are common subjective complaints among astronauts. Previous studies of sleep and hypnotic drug use in space have been limited to post-flight subjective survey data or in-flight objective data collection from a small number of crew members. We aimed to characterise representative sleep patterns of astronauts on both short-duration and long-duration spaceflight missions. For this observational study, we recruited crew members assigned to Space Transportation System shuttle flights with in-flight experiments between July 12, 2001, and July 21, 2011, or assigned to International Space Station (ISS) expeditions between Sept 18, 2006, and March 16, 2011. We assessed sleep-wake timing objectively via wrist actigraphy, and subjective sleep characteristics and hypnotic drug use via daily logs, in-flight and during Earth-based data-collection intervals: for 2 weeks scheduled about 3 months before launch, 11 days before launch until launch day, and for 7 days upon return to Earth. We collected data from 64 astronauts on 80 space shuttle missions (26 flights, 1063 in-flight days) and 21 astronauts on 13 ISS missions (3248 in-flight days), with ground-based data from all astronauts (4014 days). Crew members attempted and obtained significantly less sleep per night as estimated by actigraphy during space shuttle missions (7·35 h [SD 0·47] attempted, 5·96 h [0·56] obtained), in the 11 days before spaceflight (7·35 h [0·51], 6·04 h [0·72]), and about 3 months before spaceflight (7·40 h [0·59], 6·29 h [0·67]) compared with the first week post-mission (8·01 h [0·78], 6·74 h [0·91]; p<0·0001 for both measures). Crew members on ISS missions obtained significantly less sleep during spaceflight (6·09 h [0·67]), in the 11 days before spaceflight (5·86 h [0·94]), and during the 2-week interval scheduled about 3 months before spaceflight (6·41 h [SD 0·65]) compared with in the first week post-mission (6·95 h [1·04]; p<0·0001). 61 (78%) of 78 shuttle-mission crew members reported taking a dose of sleep-promoting drug on 500 (52%) of 963 nights; 12 (75%) of 16 ISS crew members reported using sleep-promoting drugs. Sleep deficiency in astronauts was prevalent not only during space shuttle and ISS missions, but also throughout a 3 month preflight training interval. Despite chronic sleep curtailment, use of sleep-promoting drugs was pervasive during spaceflight. Because chronic sleep loss leads to performance decrements, our findings emphasise the need for development of effective countermeasures to promote sleep. The National Aeronautics and Space Administration. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Simulation Analysis of Work Based Navy Manpower Requirements

DTIC Science & Technology

2012-09-01

Workweek is also the subject of greater discussion in the 2002 CNA study. At the time, the Navy Standard Workweek was 67 hours of...policies, states that the Navy Standard Workweek includes 8 hours of sleep a day (Navy, 2007). To properly model this while also treating...system during these non-scheduled hours . Figure 4 shows an example of a sailor’s schedule as built into Arena. The graph’s x-axis represents the

Fatigue Risk Management: The Impact of Anesthesiology Residents' Work Schedules on Job Performance and a Review of Potential Countermeasures.

PubMed

Wong, Lily R; Flynn-Evans, Erin; Ruskin, Keith J

2018-04-01

Long duty periods and overnight call shifts impair physicians' performance on measures of vigilance, psychomotor functioning, alertness, and mood. Anesthesiology residents typically work between 64 and 70 hours per week and are often required to work 24 hours or overnight shifts, sometimes taking call every third night. Mitigating the effects of sleep loss, circadian misalignment, and sleep inertia requires an understanding of the relationship among work schedules, fatigue, and job performance. This article reviews the current Accreditation Council for Graduate Medical Education guidelines for resident duty hours, examines how anesthesiologists' work schedules can affect job performance, and discusses the ramifications of overnight and prolonged duty hours on patient safety and resident well-being. We then propose countermeasures that have been implemented to mitigate the effects of fatigue and describe how training programs or practice groups who must work overnight can adapt these strategies for use in a hospital setting. Countermeasures include the use of scheduling interventions, strategic naps, microbreaks, caffeine use during overnight and extended shifts, and the use of bright lights in the clinical setting when possible or personal blue light devices when the room lights must be turned off. Although this review focuses primarily on anesthesiology residents in training, many of the mitigation strategies described here can be used effectively by physicians in practice.

Randomized, Prospective Study of the Impact of a Sleep Health Program on Firefighter Injury and Disability.

PubMed

Sullivan, Jason P; O'Brien, Conor S; Barger, Laura K; Rajaratnam, Shantha M W; Czeisler, Charles A; Lockley, Steven W

2017-01-01

Firefighters' schedules include extended shifts and long work weeks which cause sleep deficiency and circadian rhythm disruption. Many firefighters also suffer from undiagnosed sleep disorders, exacerbating fatigue. We tested the hypothesis that a workplace-based Sleep Health Program (SHP) incorporating sleep health education and sleep disorders screening would improve firefighter health and safety compared to standard practice. Prospective station-level randomized, field-based intervention. US fire department. 1189 firefighters. Sleep health education, questionnaire-based sleep disorders screening, and sleep clinic referrals for respondents who screened positive for a sleep disorder. Firefighters were randomized by station. Using departmental records, in an intention-to-treat analysis, firefighters assigned to intervention stations which participated in education sessions and had the opportunity to complete sleep disorders screening reported 46% fewer disability days than those assigned to control stations (1.4 ± 5.9 vs. 2.6 ± 8.5 days/firefighter, respectively; p = .003). There were no significant differences in departmental injury or motor vehicle crash rates between the groups. In post hoc analysis accounting for intervention exposure, firefighters who attended education sessions were 24% less likely to file at least one injury report during the study than those who did not attend, regardless of randomization (OR [95% CI] 0.76 [0.60, 0.98]; χ2 = 4.56; p = .033). There were no significant changes pre- versus post-study in self-reported sleep or sleepiness in those who participated in the intervention. A firefighter workplace-based SHP providing sleep health education and sleep disorders screening opportunity can reduce injuries and work loss due to disability in firefighters. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Disparities in sleep characteristics by race/ethnicity in a population-based sample: Chicago Area Sleep Study.

PubMed

Carnethon, Mercedes R; De Chavez, Peter John; Zee, Phyllis C; Kim, Kwang-Youn A; Liu, Kiang; Goldberger, Jeffrey J; Ng, Jason; Knutson, Kristen L

2016-02-01

Prior studies report less favorable sleep characteristics among non-Whites as compared with non-Hispanic Whites. However, few population-based studies have used objective measures of sleep duration, especially in more than two racial/ethnic groups. We tested whether objectively estimated sleep duration and self-reported sleep quality varied by race and whether differences were at least partially explained by the variability in clinical, psychological, and behavioral covariates. Adults aged 35-64 years who self-identified as White, Black, Asian, or Hispanic were randomly sampled from Chicago, IL, and the surrounding suburbs. Our analytic sample included adults who had an apnea-hypopnea index <15 after one night of screening and who completed seven nights of wrist actigraphy for determination of sleep duration, sleep percentage, minutes of wake after sleep onset, and sleep fragmentation (n = 495). Daytime sleepiness was estimated using the Epworth Sleepiness Scale (ESS), and sleep quality was estimated from the Pittsburgh Sleep Quality Index (PSQI). Following statistical adjustment for age, gender, education, work schedule (ie, day vs. night shift), smoking status, depressive symptoms, body mass index (BMI), hypertension, and diabetes, sleep duration (minutes) was significantly (all p < 0.01) shorter in Black (mean = 399.5), Hispanic (mean = 411.7), and Asian (mean = 409.6) participants than in White participants (mean = 447.4). All remaining sleep characteristics were significantly less favorable among Black participants as compared with White participants. Asian participants also reported significantly more daytime sleepiness than did White participants. Differences in sleep characteristics by race/ethnicity are apparent in a sample of adults with a low probability of sleep apnea and following adjustment for known confounders. Copyright © 2015 Elsevier B.V. All rights reserved.

A work-life perspective on sleep and fatigue--looking beyond shift workers.

PubMed

Skinner, Natalie; Dorrian, Jill

2015-01-01

This study examines sleep and fatigue through a work-life lens. Whilst most often thought of as an issue for shift workers, this study observed that self-reported insufficient sleep and fatigue were prevalent for workers on standard daytime schedules. Using a representative sample of 573 daytime workers (51.3% men; 70.7% aged 25-54 yr) from one Australian state, it was observed that 26.4% of daytime workers never or rarely get the seven hours of sleep a night that is recommended for good health. Those with parenting responsibilites (29.4%) or working long (45+) hours (37.4%) were most likely to report insufficient sleep. Whereas mothers in full-time work were most likely to report frequent fatigue (42.5%). This study highlights the common experience of insufficient sleep and fatigue in a daytime workforce, with significant implications for health and safety at work and outside of work. Stronger and more effective legislation addressing safe and 'decent' working time is clearly needed, along with greater awareness and acceptance within workplace cultures of the need to support reasonable workloads and working hours.

Correlates to sleepiness on night shift among male workers engaged in three-shift work in a chemical plant: its association with sleep practice and job stress.

PubMed

Kageyama, Takayuki; Kobayashi, Toshio; Abe-Gotoh, Ayano

2011-01-01

The purpose of this study was to examine the correlation of sleepiness during night shift (SNS) in male shiftworkers with nonpharmacological self-management (nPSM) practices to facilitate good day sleep, and also with job stress. Sleepiness on the job and possible correlates to SNS among 157 male shiftworkers in a rotating three-shift schedule at a chemical plant were cross-sectionally investigated using a self-administered questionnaire. Multivariate analyses revealed that SNS was positively associated with drinking alcoholic beverages before day sleep, but inversely associated with subjective health status, being of the evening type, abstaining from caffeine before day sleep, having a bath before day sleep, job control, reward from work, feeling suited to the job, and support from colleagues. SNS correlated with certain nPSM practices and also with possible modifiers of job stress. These findings provide clues to developing countermeasures against SNS among shiftworkers. The effects of nPSM practices and job stress management on their day sleep and SNS should be examined in detail.

Assessment Of Noise-induced Sleep Fragility In Two Age Ranges By Means Of Polysomnographic Microstructure

NASA Astrophysics Data System (ADS)

Terzano, M. G.; Parrino, L.; Spaggiari, M. C.; Buccino, G. P.; Fioriti, G.; Depoortere, H.

1993-04-01

The microstructure of sleep, which translates the short-lived fluctuations of the arousal level, is a commonly neglected feature in polysomnographic studies. Specifically arranged microstructural EEG events may provide important information on the dynamic characteristics of the sleep process. CAP (cyclic alternating pattern) and non-CAP are complementary modalities in which arousal-related "phasic" EEG phenomena are organized in non-REM sleep, and they correspond to opposite conditions of unstable and stable sleep depth, respectively. Thus, arousal instability can be measured by the CAP rate, the percentage ratio of total CAP time to total non-REM sleep time. The CAP rate, an age-related physiological variable that increases in several pathological conditions, is highly sensitive to acoustic perturbation. In the present study, two groups of healthy subjects without complaints about sleep, belonging to different age ranges (six young adults, three males and three females, between 20 and 30 years, and six middle-aged individuals, three males and three females, between 40 and 55 years) slept, after adaptation to the sleep laboratory, in a random sequence for two non-consecutive nights either under silent baseline (27·3 dB(A) Lcq) or noise-disturbed (continuous 55 dB(A) white noise) conditions. Age-related and noise-related effects on traditional sleep parameters and on the CAP rate were statistically evaluated by a split-plot test. Compared to young adults, the middle-aged individuals showed a significant reduction of total sleep time, stage 2 and REM sleep and significantly higher values of nocturnal awakenings and the CAP rate. The noisy nights were characterized by similar alterations. The disruptive effects of acoustic perturbation were greater on the more fragile sleep architecture of the older group. The increased fragility of sleep associated with aging probably reflects the decreased capacity of the sleeping brain to maintain steady states of vigilance. Total non-REM sleep described by traditional parameters was statistically unaffected during the disturbed nights, but the perturbing effects of noise on non-REM sleep stability and continuity were revealed by a significant increase in the CAP rate. The perspectives for a wide-ranging exploitation of this sleep parameter are discussed.

Circadian Rhythm Sleep Disorder, Free-Running Type in a Sighted Male with Severe Depression, Anxiety, and Agoraphobia

PubMed Central

Brown, Mark A.; Quan, Stuart F.; Eichling, Philip S.

2011-01-01

Circadian rhythm sleep disorder, free-running type (CRSD, FRT) is a disorder in which the intrinsic circadian rhythm is no longer entrained to the 24-hour schedule. A unique case of CRSD, FRT in a 67-year-old sighted male is presented. The patient had a progressively delayed time in bed (TIB) each night, so that he would cycle around the 24-h clock approximately every 30 days. This was meticulously documented each night by the patient over the course of 22 years. The patient's CRSD, FRT was associated with severe depression, anxiety, and agoraphobia. The agoraphobia may have exacerbated the CRSD, FRT. Entrainment and stabilization of his circadian rhythm was accomplished after treatment that included melatonin, light therapy, and increased sleep structure. Citation: Brown MA; Quan SF; Eichling PS. Circadian rhythm sleep disorder, free-running type in a sighted male with severe depression, anxiety, and agoraphobia. J Clin Sleep Med 2011;7(1):93-94. PMID:21344043

A Novel Energy Efficient Topology Control Scheme Based on a Coverage-Preserving and Sleep Scheduling Model for Sensor Networks

PubMed Central

Shi, Binbin; Wei, Wei; Wang, Yihuai; Shu, Wanneng

2016-01-01

In high-density sensor networks, scheduling some sensor nodes to be in the sleep mode while other sensor nodes remain active for monitoring or forwarding packets is an effective control scheme to conserve energy. In this paper, a Coverage-Preserving Control Scheduling Scheme (CPCSS) based on a cloud model and redundancy degree in sensor networks is proposed. Firstly, the normal cloud model is adopted for calculating the similarity degree between the sensor nodes in terms of their historical data, and then all nodes in each grid of the target area can be classified into several categories. Secondly, the redundancy degree of a node is calculated according to its sensing area being covered by the neighboring sensors. Finally, a centralized approximation algorithm based on the partition of the target area is designed to obtain the approximate minimum set of nodes, which can retain the sufficient coverage of the target region and ensure the connectivity of the network at the same time. The simulation results show that the proposed CPCSS can balance the energy consumption and optimize the coverage performance of the sensor network. PMID:27754405

A Novel Energy Efficient Topology Control Scheme Based on a Coverage-Preserving and Sleep Scheduling Model for Sensor Networks.

PubMed

Shi, Binbin; Wei, Wei; Wang, Yihuai; Shu, Wanneng

2016-10-14

In high-density sensor networks, scheduling some sensor nodes to be in the sleep mode while other sensor nodes remain active for monitoring or forwarding packets is an effective control scheme to conserve energy. In this paper, a Coverage-Preserving Control Scheduling Scheme (CPCSS) based on a cloud model and redundancy degree in sensor networks is proposed. Firstly, the normal cloud model is adopted for calculating the similarity degree between the sensor nodes in terms of their historical data, and then all nodes in each grid of the target area can be classified into several categories. Secondly, the redundancy degree of a node is calculated according to its sensing area being covered by the neighboring sensors. Finally, a centralized approximation algorithm based on the partition of the target area is designed to obtain the approximate minimum set of nodes, which can retain the sufficient coverage of the target region and ensure the connectivity of the network at the same time. The simulation results show that the proposed CPCSS can balance the energy consumption and optimize the coverage performance of the sensor network.

Practice parameters for the clinical evaluation and treatment of circadian rhythm sleep disorders. An American Academy of Sleep Medicine report.

PubMed

Morgenthaler, Timothy I; Lee-Chiong, Teofilo; Alessi, Cathy; Friedman, Leah; Aurora, R Nisha; Boehlecke, Brian; Brown, Terry; Chesson, Andrew L; Kapur, Vishesh; Maganti, Rama; Owens, Judith; Pancer, Jeffrey; Swick, Todd J; Zak, Rochelle

2007-11-01

The expanding science of circadian rhythm biology and a growing literature in human clinical research on circadian rhythm sleep disorders (CRSDs) prompted the American Academy of Sleep Medicine (AASM) to convene a task force of experts to write a review of this important topic. Due to the extensive nature of the disorders covered, the review was written in two sections. The first review paper, in addition to providing a general introduction to circadian biology, addresses "exogenous" circadian rhythm sleep disorders, including shift work disorder (SWD) and jet lag disorder (JLD). The second review paper addresses the "endogenous" circadian rhythm sleep disorders, including advanced sleep phase disorder (ASPD), delayed sleep phase disorder (DSPD), irregular sleep-wake rhythm (ISWR), and the non-24-hour sleep-wake syndrome (nonentrained type) or free-running disorder (FRD). These practice parameters were developed by the Standards of Practice Committee and reviewed and approved by the Board of Directors of the AASM to present recommendations for the assessment and treatment of CRSDs based on the two accompanying comprehensive reviews. The main diagnostic tools considered include sleep logs, actigraphy, the Morningness-Eveningness Questionnaire (MEQ), circadian phase markers, and polysomnography. Use of a sleep log or diary is indicated in the assessment of patients with a suspected circadian rhythm sleep disorder (Guideline). Actigraphy is indicated to assist in evaluation of patients suspected of circadian rhythm disorders (strength of recommendation varies from "Option" to "Guideline," depending on the suspected CRSD). Polysomnography is not routinely indicated for the diagnosis of CRSDs, but may be indicated to rule out another primary sleep disorder (Standard). There is insufficient evidence to justify the use of MEQ for the routine clinical evaluation of CRSDs (Option). Circadian phase markers are useful to determine circadian phase and confirm the diagnosis of FRD in sighted and unsighted patients but there is insufficient evidence to recommend their routine use in the diagnosis of SWD, JLD, ASPD, DSPD, or ISWR (Option). Additionally, actigraphy is useful as an outcome measure in evaluating the response to treatment for CRSDs (Guideline). A range of therapeutic interventions were considered including planned sleep schedules, timed light exposure, timed melatonin doses, hypnotics, stimulants, and alerting agents. Planned or prescribed sleep schedules are indicated in SWD (Standard) and in JLD, DSPD, ASPD, ISWR (excluding elderly-demented/nursing home residents), and FRD (Option). Specifically dosed and timed light exposure is indicated for each of the circadian disorders with variable success (Option). Timed melatonin administration is indicated for JLD (Standard); SWD, DSPD, and FRD in unsighted persons (Guideline); and for ASPD, FRD in sighted individuals, and for ISWR in children with moderate to severe psychomotor retardation (Option). Hypnotic medications may be indicated to promote or improve daytime sleep among night shift workers (Guideline) and to treat jet lag-induced insomnia (Option). Stimulants may be indicated to improve alertness in JLD and SWD (Option) but may have risks that must be weighed prior to use. Modafinil may be indicated to improve alertness during the night shift for patients with SWD (Guideline).

Treatment of a Circadian Rhythm Disturbance in a 2-Year-Old Blind Child.

ERIC Educational Resources Information Center

Mindell, J. A.; And Others

1996-01-01

The use of sleep scheduling and a daytime routine for the treatment of circadian rhythm disorder was found helpful in decreasing a blind 2-year old's nighttime wake periods and daytime sleepiness. (DB)

Tasimelteon

MedlinePlus

... clock is out of sync with the normal day-night cycle and causes a disrupted sleep schedule.) Tasimelteon ... It is usually taken without food once a day before bedtime. Take tasimelteon at the same time every night. If you are unable to take tasimelteon at ...

Association between sleep problems and symptoms of attention-deficit/hyperactivity disorder in young adults.

PubMed

Gau, Susan S F; Kessler, Ronald C; Tseng, Wan-Ling; Wu, Yu-Yu; Chiu, Yen-Nan; Yeh, Chin-Bin; Hwu, Hai-Gwo

2007-02-01

To examine the association between sleep-related problems and symptoms of attention-deficit/hyperactivity disorder (ADHD) in a community sample of young adults in Taiwan. A college-based cross-sectional survey. Two thousand two hundred eighty-four first-year college students (aged 18-20) in a university in Taiwan. Each student completed a questionnaire regarding sleep schedule (self-estimated total sleep duration and sleep need), sleep problems (dyssomnia, parasomnia, and snoring), and the Chinese version of the Adult ADHD Self-Report Scale. Subjects were grouped separately for the inattention and hyperactivity subscales into highly likely ADHD (2.3%, 0.7%), probable ADHD (21.3%, 5.7%), and probably non-ADHD (76.4%, 93.6%) groups according to the scoring scheme of the subscales of the Adult ADHD Self-Report Scale. Results showed that, for both inattention and hyperactivity symptoms, the highly likely ADHD and probable ADHD groups were more likely than the non-ADHD group to have a variety of current and lifetime sleep problems. No significant difference in sleep problems was found between the highly likely ADHD and probable ADHD groups. Inattention, but not hyperactivity, was associated with greater sleep need and greater difference between sleep need and self-estimated nocturnal sleep duration. Hyperactivity, but not inattention, was associated with decreased nocturnal sleep duration. Consistent with prior findings from children and adolescents, ADHD symptoms in young adults are related to sleep problems. Further studies on adults with ADHD should help to refine our understanding of the causal basis for any implications of this association.

Prevalence of poor sleep quality, sleepiness and obstructive sleep apnoea risk factors in athletes.

PubMed

Swinbourne, Richard; Gill, Nicholas; Vaile, Joanna; Smart, Daniel

2016-10-01

Despite the perceived importance of sleep for athletes, little is known regarding athlete sleep quality, their prevalence of daytime sleepiness or risk factors for obstructive sleep apnoea (OSA) such as snoring and witnessed apnoeic episodes. The purpose of the present study was to characterise normative sleep quality among highly trained team sport athletes. 175 elite or highly trained rugby sevens, rugby union and cricket athletes completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Score (ESS) and Quality of Life questionnaires and an OSA risk factor screen. On average, athletes reported 7.9 ± 1.3 h of sleep per night. The average PSQI score was 5.9 ± 2.6, and 50% of athletes were found to be poor sleepers (PSQI > 5). Daytime sleepiness was prevalent throughout the population (average global score of 8.5) and clinically significant (ESS score of ≥10) in 28% of athletes. OSA may be an important clinical consideration within athletic populations, as a considerable number of athletes (38%) defined themselves as snorers and 8% reported having a witnessed apnoeic episode. The relationship between self-rated sleep quality and actual PSQI score was strong (Pearson correlation of 0.4 ± 0.1, 90% confidence limits). These findings suggest that this cohort of team sport athletes suffer a preponderance of poor sleep quality, with associated high levels of daytime sleepiness. Athletes should receive education about how to improve sleep wake schedules, extend total sleep time and improve sleep quality.

Acute Effects of 24-h Sleep Deprivation on Salivary Cortisol and Testosterone Concentrations and Testosterone to Cortisol Ratio Following Supplementation with Caffeine or Placebo

PubMed Central

DONALD, CIARAN MC; MOORE, JOSS; MCINTYRE, ALAN; CARMODY, KEVIN; DONNE, BERNARD

2017-01-01

Caffeine has become a popular ergogenic aid amongst athletes and usage to improve athletic performance has been well documented. The effect of caffeine on anabolic and catabolic hormones in a sleep-deprived s tate has had little investigation to date. The purpose of the current study was to investigate the potential of caffeine to offset the effects, if any, of short-term sleep deprivation and exercise on an athlete’s testosterone and cortisol concentrations via salivary technique. Eleven competitive male athletes volunteered to be part of this prospective double-blinded study. Three test days were scheduled for each athlete; one non-sleep deprived, one sleep-deprived with caffeine supplementation (6 mg.kg−1) and one sleep-deprived with placebo ingestion. Sleep deprivation was defined as 24-h without sleep. Each test day was composed of 2 aerobic components: a modified Hoff test and a Yo-Yo test. Testosterone and cortisol concentrations were measured via salivary analysis at 4 different time-points; T1 to T4, representing baseline, and pre- and post-aerobic components, respectively. Overall no significant differences were detected comparing the different sleep states for testosterone or cortisol concentrations. A trend existed whereby the sleep-deprived with caffeine ingestion state mirrored the non-sleep deprived state for cortisol concentration. Therefore, caffeine supplementation may have potential benefits for athletes during short-term aerobic exercise when sleep-deprived. An increase in mean testosterone concentration post-aerobic exercise was only observed in the sleep-deprived with caffeine ingestion state. PMID:28479951

Sustained-release theophylline and nocturnal asthma, once-daily and unequal dosing schedules.

PubMed

Smolensky, M H; D'Alonzo, G E; Kunkel, G; Barnes, P J

1987-01-01

Many asthmatic patients experience aggravation of symptoms overnight resulting in disruption of their sleep. Sustained-release theophylline represents at this time a major bronchodilator medication which possesses a sufficient duration of activity to avert the nocturnal breathing distress of asthma. Circadian rhythm-adapted theophylline schedules consisting of unequal dosing--more or all the drug taken in the evening--have proven efficacious in clinical investigations for certain patients. Although the kinetic behavior of some formulations is affected by food, the circadian rhythm-adapted schedules represent a significant step forward toward the goal of optimizating sustained-release theophyllines for patients who experience nighttime symptoms.

Effects of a workplace intervention on sleep in employees' children.

PubMed

McHale, Susan M; Lawson, Katie M; Davis, Kelly D; Casper, Lynne; Kelly, Erin L; Buxton, Orfeu

2015-06-01

The implications of sleep patterns for adolescent health are well established, but we know less about larger contextual influences on youth sleep. We focused on parents' workplace experiences as extrafamilial forces that may affect youth sleep. In a group-randomized trial focused on employee work groups in the information technology division of a Fortune 500 company, we tested whether a workplace intervention improved sleep latency, duration, night-to-night variability in duration, and quality of sleep of employees' offspring, aged 9-17 years. The intervention was aimed at promoting employees' schedule control and supervisor support for personal and family life to decrease employees' work-family conflict and thereby promote the health of employees, their families, and the work organization. Analyses focused on 93 parent-adolescent dyads (57 dyads in the intervention and 46 in the comparison group) that completed baseline and 12-month follow-up home interviews and a series of telephone diary interviews that were conducted on eight consecutive evenings at each wave. Intent-to-treat analyses of the diary interview data revealed main effects of the intervention on youth's sleep latency, night-to-night variability in sleep duration, and sleep quality, but not sleep duration. The intervention focused on parents' work conditions, not on their parenting or parent-child relationships, attesting to the role of larger contextual influences on youth sleep and the importance of parents' work experiences in the health of their children. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

To Assess Sleep Quality among Pakistani Junior Physicians (House Officers): A Cross-sectional Study.

PubMed

Surani, A A; Surani, A; Zahid, S; Ali, S; Farhan, R; Surani, S

2015-01-01

Sleep deprivation among junior physicians (house officers) is of growing concern. In developed countries, duty hours are now mandated, but in developing countries, junior physicians are highly susceptible to develop sleep impairment due to long working hours, on-call duties and shift work schedule. We undertook the study to assess sleep quality among Pakistani junior physicians. A cross-sectional study was conducted at private and public hospitals in Karachi, Pakistan, from June 2012 to January 2013. The study population comprised of junior doctors (house physicians and house surgeons). A consecutive sample of 350 physicians was drawn from the above-mentioned study setting. The subject underwent two validated self-administered questionnaires, that is, Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). A total of 334 physicians completely filled out the questionnaire with a response rate of 95.4% (334/350). Of 334 physicians, 36.8% (123/334) were classified as "poor sleepers" (global PSQI score > 5). Poor sleep quality was associated with female gender (P = 0.01), excessive daytime sleepiness (P < 0.01), lower total sleep time (P < 0.001), increased sleep onset latency (P < 0.001), and increased frequency of sleep disturbances (P < 0.001). Abnormal ESS scores (ESS > 10) were more prevalent among poor sleepers (P < 0.01) signifying increased level of daytime hypersomnolence. Sleep quality among Pakistani junior physicians is significantly poor. Efforts must be directed towards proper sleep hygiene education. Regulations regarding duty hour limitations need to be considered.

Evening daylight may cause adolescents to sleep less in spring than in winter

PubMed Central

Figueiro, Mariana G.; Rea, Mark S.

2012-01-01

Sleep restriction commonly experienced by adolescents can stem from greater sleep pressure by the homeostatic processes and from phase delays of the circadian system. With regard to the latter potential cause, we hypothesized that because there is more natural evening light during the spring than winter, a sample of adolescent students would be more phase delayed in spring than in winter, would have later sleep onset times and, because of fixed school schedules, would have shorter sleep durations. Sixteen eighth-grade subjects were recruited for the study. We collected sleep logs and saliva samples to determine their dim light melatonin onset (DLMO), a well-established circadian marker. Actual circadian light exposures experienced by a subset of twelve subjects over the course of seven days in winter and in spring using a personal, head-worn, circadian light measurement device are also reported here. Results showed that this sample of adolescents was exposed to significantly more circadian light in spring than in winter, especially in the evening hours when light exposure would likely delay circadian phase. Consistent with the light data, DLMO and sleep onset times were significantly more delayed, and sleep durations were significantly shorter in spring than in winter. The present ecological study of light, circadian phase, and self-reported sleep suggests that greater access to evening daylight in the spring may lead to sleep restriction in adolescents while attending school. Therefore, lighting schemes that reduce evening light in the spring may encourage longer sleep times in adolescents. PMID:20653452

Excessive Video Game Use, Sleep Deprivation, and Poor Work Performance Among U.S. Marines Treated in a Military Mental Health Clinic: A Case Series.

PubMed

Eickhoff, Erin; Yung, Kathryn; Davis, Diane L; Bishop, Frank; Klam, Warren P; Doan, Andrew P

2015-07-01

Excessive use of video games may be associated with sleep deprivation, resulting in poor job performance and atypical mood disorders. Three active duty service members in the U.S. Marine Corps were offered mental health evaluation for sleep disturbance and symptoms of blunted affect, low mood, poor concentration, inability to focus, irritability, and drowsiness. All three patients reported insomnia as their primary complaint. When asked about online video games and sleep hygiene practices, all three patients reported playing video games from 30 hours to more than 60 hours per week in addition to maintaining a 40-hour or more workweek. Our patients endorsed sacrificing sleep to maintain their video gaming schedules without insight into the subsequent sleep deprivation. During the initial interviews, they exhibited blunted affects and depressed moods, but appeared to be activated with enthusiasm and joy when discussing their video gaming with the clinical provider. Our article illustrates the importance of asking about online video gaming in patients presenting with sleep disturbances, poor work performance, and depressive symptoms. Because excessive video gaming is becoming more prevalent worldwide, military mental health providers should ask about video gaming when patients report problems with sleep. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

Setting Adolescents Up for Success: Promoting a Policy to Delay High School Start Times.

PubMed

Barnes, Margaux; Davis, Krista; Mancini, Mackenzie; Ruffin, Jasmine; Simpson, Tina; Casazza, Krista

2016-07-01

A unique biological shift in sleep cycles occurs during adolescence causing later sleep and wake times. This shift is not matched by a concurrent modification in school start times, resulting in sleep curtailment for a large majority of adolescents. Chronic inadequate sleep is associated with poor academic performance including executive function impairments, mood, and behavioral issues, as well as adverse health outcomes such as an increased risk of obesity, hypertension, and cardiovascular disease. In order to address sleep deficits and the potential negative outcomes associated with chronic sleep deprivation, the American Academy of Pediatrics (AAP) and US Centers for Disease Control and Prevention (CDC) support delaying school start times for middle and high school students. We summarize current evidence, explicate the need for policy change, and urge school districts to put adolescent students' health as top priority and implement school start times consistent with their developmental needs. Whereas substantial evidence illustrating adverse consequences of inadequate sleep on psychological and physical health, and recommendations exist to adapt daytime school schedules to match sleep needs have been released, actual implementation of these recommendations have been limited. This is a call to action for the implementation of AAP/CDC recommendations across the state and nation. © 2016, American School Health Association.

Cardiac Valve Noise Reduction by Non-Drug Interventions Improves the Sleep Quality of Patients after Mechanical Cardiac Valve Implantation.

PubMed

Lin, Yanjuan; Xu, Le; Huang, Xizhen; Jiang, Fei; Lin, Fen; Ye, Qingyang; Lin, Jianling

2016-01-01

To investigate the effects of non-drug interventions on the sleep quality of patients after mechanical cardiac valve implantation. In this prospective, randomized, controlled trial, 64 patients scheduled for mechanical mitral valve replacement were recruited. Patients underwent cognitive behavioral therapy and wore noise cancelling earplugs and eye mask. Sleep quality was evaluated on the 4th after admission and the 5th days after operation. The primary outcome was the total sleep quality score differences between the 4th day after admission and the 5th day after operation. All patients had been suffering from poor sleep quality for a month before admission. There was no difference between both groups on the 4th day after admission. Overall sleep quality in the intervention group was better than in the control group on the 5th day after operation. The subjective sleep quality of the patients in each group was significantly lower on the 5th day after the operation than on the 4th day after admission (P <0.05). Non-drug intervention could improve the sleep quality of patients after mechanical cardiac valve implantation and help the postoperative recovery of the patients. ( ChiCTR-TRC-14004405, 21 March 2014.).

[Somnambulism: clinical and eletrophysiological aspects].

PubMed

Szúcs, Anna; Halász, Péter

2005-06-05

The authors review the literature on the epidemiology, the clinical and electrophysiological symptoms of somnambulism. The disorder specified as "nREM parasomnia with awakening disorder" belongs to the nREM sleep (awakening) parasomnias. In most of the cases its occurence is familial with the highest prevalence at age 12 year. Above age 12 year most cases recover whereas 6% of prevalence is reported in adults. It is probable that most patients seek medical help only in severe cases associated with injuries, accidents or violence. Its etiology is unknown; in essence it is a sleep regulation disorder characterised by a dissociated state of partial awakening from nREM sleep: the motor system becomes awake while consciousness remains clouded. There are several medicines inducing somnambulism in patients otherwise free from this disorder. In somnambule patients the most important provoking factors are sleep deprivation as well as pathological states and circumstances evoking sleep loss. Somnambulism should be differentiated from complex partial epileptic seizures and REM behaviour disorder. As there is no specific treatment at the moment it is important to assure safe sleeping circumstances - ground flour, closed windows, and no fragile furniture. Clonazepam and selective serotonin reuptake inhibitors prove sometimes effective, but the most effective methods in decreasing the frequency of somnambule episodes are the regular sleep-wakefulness schedule and the avoidance of sleep deprivation.

Acute Sleep Deprivation Blocks Short- and Long-Term Operant Memory in Aplysia

PubMed Central

Krishnan, Harini C.; Gandour, Catherine E.; Ramos, Joshua L.; Wrinkle, Mariah C.; Sanchez-Pacheco, Joseph J.; Lyons, Lisa C.

2016-01-01

Study Objectives: Insufficient sleep in individuals appears increasingly common due to the demands of modern work schedules and technology use. Consequently, there is a growing need to understand the interactions between sleep deprivation and memory. The current study determined the effects of acute sleep deprivation on short and long-term associative memory using the marine mollusk Aplysia californica, a relatively simple model system well known for studies of learning and memory. Methods: Aplysia were sleep deprived for 9 hours using context changes and tactile stimulation either prior to or after training for the operant learning paradigm, learning that food is inedible (LFI). The effects of sleep deprivation on short-term (STM) and long-term memory (LTM) were assessed. Results: Acute sleep deprivation prior to LFI training impaired the induction of STM and LTM with persistent effects lasting at least 24 h. Sleep deprivation immediately after training blocked the consolidation of LTM. However, sleep deprivation following the period of molecular consolidation did not affect memory recall. Memory impairments were independent of handling-induced stress, as daytime handled control animals demonstrated no memory deficits. Additional training immediately after sleep deprivation failed to rescue the induction of memory, but additional training alleviated the persistent impairment in memory induction when training occurred 24 h following sleep deprivation. Conclusions: Acute sleep deprivation inhibited the induction and consolidation, but not the recall of memory. These behavioral studies establish Aplysia as an effective model system for studying the interactions between sleep and memory formation. Citation: Krishnan HC, Gandour CE, Ramos JL, Wrinkle MC, Sanchez-Pacheco JJ, Lyons LC. Acute sleep deprivation blocks short- and long-term operant memory in Aplysia. SLEEP 2016;39(12):2161–2171. PMID:27748243

Verification of reliability and validity of a Japanese version of the Rathus Assertiveness Schedule.

PubMed

Suzuki, Eiko; Kanoya, Yuka; Katsuki, Takeshi; Sato, Chifumi

2007-07-01

To verify the reliability and validity of a Japanese version of the Rathus Assertiveness Schedule in novice nurses to contribute to nursing management. An adequate scale is needed to measure the assertiveness and the effect of assertion training for Japanese nurses and to compare them with those in other countries. Rathus Assertiveness Schedule was adapted to Japanese with back-translation and its validity was examined in 989 novice nurses. The Japanese version showed a high coefficient of reliability in a split-half reliability test (r=0.76; P<0.01). The coefficient of reliability of Cronbach's alpha was high (r=0.84; P<0.01) indicating high internal consistency. The similarity with the concept of stress coping was shown. We extracted eight principal factors using factor analysis with varimax rotation. Elements of these factors were similar to those of the original Rathus Assertiveness Schedule. The Japanese version of Rathus Assertiveness Schedule was verified.

Work-Family Conflict and Employee Sleep: Evidence from IT Workers in the Work, Family and Health Study

PubMed Central

Buxton, Orfeu M.; Lee, Soomi; Beverly, Chloe; Berkman, Lisa F.; Moen, Phyllis; Kelly, Erin L.; Hammer, Leslie B.; Almeida, David M.

2016-01-01

Study Objectives: Work-family conflict is a threat to healthy sleep behaviors among employees. This study aimed to examine how Work-to-Family Conflict (demands from work that interfere with one's family/personal life; WTFC) and Family-to-Work Conflict (demands from family/personal life that interfere with work; FTWC) are associated with several dimensions of sleep among information technology workers. Methods: Employees at a U.S. IT firm (n = 799) provided self-reports of sleep sufficiency (feeling rested upon waking), sleep quality, and sleep maintenance insomnia symptoms (waking up in the middle of the night or early morning) in the last month. They also provided a week of actigraphy for nighttime sleep duration, napping, sleep timing, and a novel sleep inconsistency measure. Analyses adjusted for work conditions (job demands, decision authority, schedule control, and family-supportive supervisor behavior), and household and sociodemographic characteristics. Results: Employees who experienced higher WTFC reported less sleep sufficiency, poorer sleep quality, and more insomnia symptoms. Higher WTFC also predicted shorter nighttime sleep duration, greater likelihood of napping, and longer nap duration. Furthermore, higher WTFC was linked to greater inconsistency of nighttime sleep duration and sleep clock times, whereas higher FTWC was associated with more rigidity of sleep timing mostly driven by wake time. Conclusions: Results highlight the unique associations of WTFC/FTWC with employee sleep independent of other work conditions and household and sociodemographic characteristics. Our novel methodological approach demonstrates differential associations of WTFC and FTWC with inconsistency of sleep timing. Given the strong associations between WTFC and poor sleep, future research should focus on reducing WTFC. Citation: Buxton OM, Lee S, Beverly C, Berkman LF, Moen P, Kelly EL, Hammer LB, Almeida DM. Work-family conflict and employee sleep: evidence from IT workers in the Work, Family and Health Study. SLEEP 2016;39(10):1871–1882. PMID:27568810

Using Sleep Interventions to Engage and Treat Heavy-Drinking College Students: A Randomized Pilot Study.

PubMed

Fucito, Lisa M; DeMartini, Kelly S; Hanrahan, Tess H; Yaggi, Henry Klar; Heffern, Christina; Redeker, Nancy S

2017-04-01

Continued high alcohol consumption levels by college students highlight the need for more effective alcohol interventions and novel treatment engagement strategies. The purpose of this study was to investigate a behavioral sleep intervention as a means to engage heavy-drinking college students in treatment and reduce alcohol use and alcohol-related consequences. Heavy-drinking college students (N = 42) were assigned to 1 of 2 web-based interventions comprised of 4 modules delivered over 4 weeks. The experimental intervention focused primarily on sleep and included evidence-based sleep content (i.e., stimulus control instructions, sleep scheduling [consistent bed/rise times; ideal sleep duration for adolescents/young adults], sleep hygiene advice, relaxation training, cognitive strategies to target sleep-disruptive beliefs), and alcohol content (i.e., normative and blood alcohol level feedback, moderate drinking guidelines, controlled drinking strategies, effects of alcohol on sleep and the body, advice to moderate drinking for improved sleep) in young adults. The control condition Healthy Behaviors provided basic advice about nutrition, exercise, sleep (i.e., good sleep hygiene only), and drinking (i.e., effects of alcohol on the body, moderate drinking guidelines, advice to moderate drinking for sleep). Participants in both conditions monitored their sleep using daily web-based diaries and a wrist-worn sleep tracker. Recruitment ads targeting college students with sleep concerns effectively identified heavy-drinking students. The program generated a high number of inquiries and treatment completion rates were high. Both interventions significantly reduced typical week drinking and alcohol-related consequences and improved sleep quality and sleep-related impairment ratings. The control condition yielded greater reductions in total drinks in a heaviest drinking week. The effects on drinking were larger than those observed in typical brief alcohol intervention studies for college students. Greater sleep improvement tended to predict better subsequent drinking outcomes. The results suggest that sleep treatment may be a promising strategy for targeting and treating heavy-drinking college students. Copyright © 2017 by the Research Society on Alcoholism.

Using Sleep Interventions to Engage and Treat Heavy-Drinking College Students: A Randomized Pilot Study

PubMed Central

Fucito, Lisa M.; DeMartini, Kelly S.; Hanrahan, Tess H.; Yaggi, Henry Klar; Heffern, Christina; Redeker, Nancy S.

2017-01-01

Background Continued high alcohol consumption levels by college students highlight the need for more effective alcohol interventions and novel treatment engagement strategies. The purpose of this study was to investigate a behavioral sleep intervention as a means to engage heavy-drinking college students in treatment and reduce alcohol use and alcohol-related consequences. Methods Heavy-drinking college students (N=42) were assigned to 1 of 2 web-based interventions comprised of 4 modules delivered over 4 weeks. The experimental intervention focused primarily on sleep and included evidence-based sleep content (i.e., stimulus control instructions, sleep scheduling (consistent bed/rise times; ideal sleep duration for adolescents/young adults), sleep hygiene advice, relaxation training, cognitive strategies to target sleep-disruptive beliefs) and alcohol content (i.e., normative and blood alcohol level feedback, moderate drinking guidelines, controlled drinking strategies, effects of alcohol on sleep and the body, advice to moderate drinking for improved sleep) in young adults. The healthy behaviors control condition provided basic advice about nutrition, exercise, sleep (i.e., good sleep hygiene only) and drinking (i.e., effects of alcohol on the body, moderate drinking guidelines, advice to moderate drinking for sleep). Participants in both conditions monitored their sleep using daily web-based diaries and a wrist-worn sleep tracker. Results Recruitment ads targeting college students with sleep concerns effectively identified heavy-drinking students. The program generated a high number of inquiries and treatment completion rates were high. Both interventions significantly reduced typical week drinking and alcohol-related consequences and improved sleep quality and sleep-related impairment ratings. The control condition yielded greater reductions in total drinks in a heaviest drinking week. The effects on drinking were larger than those observed in typical brief alcohol intervention studies for college students. Greater sleep improvement tended to predict better subsequent drinking outcomes. The results suggest that sleep treatment may be a promising strategy for targeting and treating heavy-drinking college students. PMID:28118486

Nonstandard working schedules and health: the systematic search for a comprehensive model.

PubMed

Merkus, Suzanne L; Holte, Kari Anne; Huysmans, Maaike A; van Mechelen, Willem; van der Beek, Allard J

2015-10-23

Theoretical models on shift work fall short of describing relevant health-related pathways associated with the broader concept of nonstandard working schedules. Shift work models neither combine relevant working time characteristics applicable to nonstandard schedules nor include the role of rest periods and recovery in the development of health complaints. Therefore, this paper aimed to develop a comprehensive model on nonstandard working schedules to address these shortcomings. A literature review was conducted using a systematic search and selection process. Two searches were performed: one associating the working time characteristics time-of-day and working time duration with health and one associating recovery after work with health. Data extracted from the models were used to develop a comprehensive model on nonstandard working schedules and health. For models on the working time characteristics, the search strategy yielded 3044 references, of which 26 met the inclusion criteria that contained 22 distinctive models. For models on recovery after work, the search strategy yielded 896 references, of which seven met the inclusion criteria containing seven distinctive models. Of the models on the working time characteristics, three combined time-of-day with working time duration, 18 were on time-of-day (i.e. shift work), and one was on working time duration. The model developed in the paper has a comprehensive approach to working hours and other work-related risk factors and proposes that they should be balanced by positive non-work factors to maintain health. Physiological processes leading to health complaints are circadian disruption, sleep deprivation, and activation that should be counterbalanced by (re-)entrainment, restorative sleep, and recovery, respectively, to maintain health. A comprehensive model on nonstandard working schedules and health was developed. The model proposes that work and non-work as well as their associated physiological processes need to be balanced to maintain good health. The model gives researchers a useful overview over the various risk factors and pathways associated with health that should be considered when studying any form of nonstandard working schedule.

Restless Legs Syndrome/Willis-Ekbom Disease Is Prevalent in Working Nurses, but Seems Not to Be Associated with Shift Work Schedules.

PubMed

Waage, Siri; Pallesen, Ståle; Moen, Bente Elisabeth; Bjorvatn, Bjørn

2018-01-01

Insomnia and excessive sleepiness are among the most commonly reported sleep problems related to shift work. Sleep-related movement disorders have, however, received far less attention in relation to such work schedules. The objective of this study was to investigate the association between different shift work schedules and the prevalence of Restless legs syndrome/Willis-Ekbom disease (RLS/WED) in a large sample of Norwegian nurses. Our hypothesis was that shift working nurses would report higher prevalence of RLS/WED compared to day workers. A total of 1,788 nurses with different work schedules (day work, two-shift rotation, night work, three shift rotation) participated in a cohort study, started in 2008/2009. Four questions about RLS/WED based on the diagnostic criteria were included in wave 4 (2012). RLS/WED prevalence rates across different shift schedules were explored by the Pearson chi-square test. Logistic regression analysis was used to assess the association between RLS/WED and work schedules and shift work disorder (SWD) with adjustment for sex, age, marital status, smoking, and caffeine use. In total, 90.0% of the nurses were females, mean age 36.5 years (SD = 8.6, range 25-67). The overall prevalence of RLS/WED was 26.8%. We found no significant differences between the prevalence of RLS/WED across the different shift schedules, ranging from 23.3% (day work) to 29.4% (night work). There was a significant difference ( p  < 0.001) in the prevalence of RLS/WED between nurses having SWD (33.5%) compared to nurses not having SWD (23.8%). SWD remained significantly associated with RLS/WED in the adjusted logistic regression analysis (1.56, CI: 1.24-1.97). This study did not support the hypothesis. RLS/WED was associated with SWD, which might indicate that nurses vulnerable to shift work also are sensitive to other complaints related to a misalignment of the biological clock.

Impact of Sleep Telemedicine Protocol in Management of Sleep Apnea: A 5-Year VA Experience.

PubMed

Baig, Mirza M; Antonescu-Turcu, Andrea; Ratarasarn, Kavita

2016-05-01

There is growing evidence that demonstrates an important role for telemedicine technologies in enhancing healthcare delivery. A comprehensive sleep telemedicine protocol was implemented at the Veterans Administration Medical Center (VAMC), Milwaukee, WI, in 2008 in an effort to improve access to sleep specialty care. The telemedicine protocol relied heavily on sleep specialist interventions based on chart review (electronic consult [e-consult]). This was done in response to long wait time for sleep clinic visits as well as delayed sleep study appointments. Since 2008 all consults are screened by sleep service to determine the next step in intervention. Based on chart review, the following steps are undertaken: (1) eligibility for portable versus in-lab sleep study is determined, and a sleep study order is placed accordingly, (2) positive airway pressure (PAP) therapy is prescribed for confirmed sleep apnea, and (3) need for in-person evaluation in the sleep clinic is determined, and the visit is scheduled. This study summarizes the 5-year trend in various aspects of access to sleep care after implementation of sleep telemedicine protocol at the Milwaukee VAMC. This is a retrospective system efficiency study. The electronic medical record was interrogated 5 years after starting the sleep telemedicine protocol to study annual trends in the following outcomes: (1) interval between sleep consult and prescription of PAP equipment, (2) total sleep consults, and (3) sleep clinic wait time. Two part-time sleep physicians provided sleep-related care at the Milwaukee VAMC between 2008 and 2012. During this period, the interval between sleep consult and PAP prescription decreased from ≥60 days to ≤7 days. This occurred in spite of an increase in total sleep consults and sleep studies. There was also a significant increase in data downloads, indicating overall improved follow-up. There was no change in clinic wait time of ≥60 days. Implementation of a sleep telemedicine protocol at the Milwaukee VAMC was associated with increased efficiency of sleep services. Timeliness of sleep management interventions for sleep apnea improved in spite of the increased volume of service.

Impact of delaying school start time on adolescent sleep, mood, and behavior.

PubMed

Owens, Judith A; Belon, Katherine; Moss, Patricia

2010-07-01

To examine the impact of a 30-minute delay in school start time on adolescents' sleep, mood, and behavior. Participants completed the online retrospective Sleep Habits Survey before and after a change in school start time. An independent high school in Rhode Island. Students (n = 201) in grades 9 through 12. Intervention Institution of a delay in school start time from 8 to 8:30 am. Sleep patterns and behavior, daytime sleepiness, mood, data from the Health Center, and absences/tardies. After the start time delay, mean school night sleep duration increased by 45 minutes, and average bedtime advanced by 18 minutes (95% confidence interval, 7-29 minutes [t(423) = 3.36; P < .001]); the percentage of students getting less than 7 hours of sleep decreased by 79.4%, and those reporting at least 8 hours of sleep increased from 16.4% to 54.7%. Students reported significantly more satisfaction with sleep and experienced improved motivation. Daytime sleepiness, fatigue, and depressed mood were all reduced. Most health-related variables, including Health Center visits for fatigue-related complaints, and class attendance also improved. A modest delay in school start time was associated with significant improvements in measures of adolescent alertness, mood, and health. The results of this study support the potential benefits of adjusting school schedules to adolescents' sleep needs, circadian rhythm, and developmental stage.

Sleep Quality Associated With Different Work Schedules: A Longitudinal Study of Nursing Staff.

PubMed

Niu, Shu-Fen; Miao, Nae-Fang; Liao, Yuan-Mei; Chi, Mei-Ju; Chung, Min-Huey; Chou, Kuei-Ru

2017-07-01

To explore the differences in sleep parameters between nurses working a slow, forward rotating shift and those working a fixed day shift. A longitudinal parallel-group comparison design was used in this prospective study. Participants (female) were randomly assigned to a rotating shift or a fixed day shift group. Participants in the rotating shift group worked day shift for the first 4 weeks, followed by evening shift for the second and night shift the third. Those in the day shift group worked day shift for all 12 weeks. Each kept a sleep diary and wore an actigraph (actigraph data were used to calculate total sleep time [TST], sleep onset latency [SOL], wake after sleep onset [WASO], and sleep efficiency [SE]) for 12 days, from Workday 1-4 in each of Weeks 4, 8, and 12. TST in nurses working evening rotating shift was higher than that for those working the day or night rotating shift and fixed day shift. WASO was significantly longer on Day 2 for rotating shift participants working evening versus day shift. SOL and SE were significantly shorter and lower in rotating shift nurses working night versus both day and evening shifts. A comprehensive understanding of the sleep patterns and quality of nurses with different work shifts may lead to better management of work shifts that reduces the influence of shift work on sleep quality.

Modified Interim Mandibular Advancement (MIMA) Appliance for Symptomatic Correction of Obstructive Sleep Apnea

PubMed Central

Singh, Harpreet; Mishra, Harsh Ashok; Gupta, Ankur

2016-01-01

Obstructive Sleep Apnea (OSA) is a chronic, progressive, multifactorial, life-threatening disorder that causes significant impact on patient’s life. Patients with OSA [Apnea/Hypopnea Index (AHI)>30] who cannot tolerate Continuous Positive Airway Pressure (CPAP) therapy or are not surgical candidates may benefit from oral appliances. This paper describes interim appliance devised from existing Hawley’s retainer in patients with OSA. A 38-year-old man of athletic built with history of orthodontic treatment six months back due to esthetic concerns and wearing upper Hawley’s retainer, reported with chief complaint of frequent nocturnal awakening along with excessive daytime somnolence. Based on diagnostic aids, he was diagnosed with Class II Division 1 malocclusion with severe mandibular retrusion. Sleep test revealed AHI score of 34, suggestive of severe OSA. With ENT and Oral surgeon concurrence, mandibular advancement of 7mm with Bilateral Sagital Split Osteotomy (BSSO) with distraction was contemplated as a viable functional and curative stable treatment plan. Because of non-adherence and non-compliance with CPAP therapy and on request of patient, an interim anterior positioning appliance was devised to facilitate comfortable sound sleep till the time surgery is impending. After three months of wearing this customized appliance, improved quality of sleep was discernible; both subjectively as reported by patient and objectively using sleep test (AHI=9.8). PMID:27656589

Increased Automaticity and Altered Temporal Preparation Following Sleep Deprivation.

PubMed

Kong, Danyang; Asplund, Christopher L; Ling, Aiqing; Chee, Michael W L

2015-08-01

Temporal expectation enables us to focus limited processing resources, thereby optimizing perceptual and motor processing for critical upcoming events. We investigated the effects of total sleep deprivation (TSD) on temporal expectation by evaluating the foreperiod and sequential effects during a psychomotor vigilance task (PVT). We also examined how these two measures were modulated by vulnerability to TSD. Three 10-min visual PVT sessions using uniformly distributed foreperiods were conducted in the wake-maintenance zone the evening before sleep deprivation (ESD) and three more in the morning following approximately 22 h of TSD. TSD vulnerable and nonvulnerable groups were determined by a tertile split of participants based on the change in the number of behavioral lapses recorded during ESD and TSD. A subset of participants performed six additional 10-min modified auditory PVTs with exponentially distributed foreperiods during rested wakefulness (RW) and TSD to test the effect of temporal distribution on foreperiod and sequential effects. Sleep laboratory. There were 172 young healthy participants (90 males) with regular sleep patterns. Nineteen of these participants performed the modified auditory PVT. Despite behavioral lapses and slower response times, sleep deprived participants could still perceive the conditional probability of temporal events and modify their level of preparation accordingly. Both foreperiod and sequential effects were magnified following sleep deprivation in vulnerable individuals. Only the foreperiod effect increased in nonvulnerable individuals. The preservation of foreperiod and sequential effects suggests that implicit time perception and temporal preparedness are intact during total sleep deprivation. Individuals appear to reallocate their depleted preparatory resources to more probable event timings in ongoing trials, whereas vulnerable participants also rely more on automatic processes. © 2015 Associated Professional Sleep Societies, LLC.

Sleep Environments and Sleep Durations in a Sample of Low-Income Preschool Children

PubMed Central

Wilson, Katherine E.; Miller, Alison L.; Lumeng, Julie C.; Chervin, Ronald D.

2014-01-01

Study Objectives: Sleep duration is commonly studied in children, but less is known about the potential impact of adverse sleep environments, particularly at preschool ages. We examined the frequency of suboptimal sleep environments and tested for associations with sleep duration or nocturnal sleep time among low-income preschool children. Methods: Parents of Head Start preschoolers in Michigan (Detroit and greater Lansing) completed questionnaires on children's sleep schedules and sleep environments. Respondents indicated how often their children slept in a place “too bright,” “too loud,” “too cold,” or “too hot” on a scale of 1 = never to 5 = always. A suboptimal sleep environment (SSE) was defined when one or more of these conditions were reported for ≥ 1-2 nights/week. Weeknight sleep duration or reported time that the child went to sleep was regressed on SSE as an explanatory variable, with adjustment for age, race/ethnicity, gender, maternal education, and average daily nap duration. Results: Among 133 preschool children, mean age was 4.1 ± 0.5 (SD), 48% were male, 39% were white, and 52% were black; 34% of parents had ≤ a high school degree. Parents reported that 26 (20%) of the children slept in a SSE ≥ 1-2 nights per week. In regression models, SSE was associated with 27 minutes shorter sleep duration (β = -0.45, SE = 0.22, p = 0.044) and 22 minutes later time child “fell asleep” (β = 0.37, SE = 0.19, p = 0.048) on weeknights. Conclusions: Among these Head Start preschool children, environmental challenges to adequate sleep are not uncommon, and they may have consequences. Clinician or preschool assessment of sleep environments may open opportunities to improve sleep at early ages. Citation: Wilson KE; Miller AL; Lumeng JC; Chervin RD. Sleep environments and sleep durations in a sample of low-income preschool children. J Clin Sleep Med 2014;10(3):299-305. PMID:24634628

Sleep and circadian variability in people with delayed sleep-wake phase disorder versus healthy controls.

PubMed

Burgess, Helen J; Park, Margaret; Wyatt, James K; Rizvydeen, Muneer; Fogg, Louis F

2017-06-01

To compare sleep and circadian variability in adults with delayed sleep-wake phase disorder (DSWPD) to healthy controls. Forty participants (22 DSWPD, 18 healthy controls) completed a ten-day protocol, consisting of DLMO assessments on two consecutive nights, a five-day study break, followed by two more DLMO assessments. All participants were instructed to sleep within one hour of their self-reported average sleep schedule for the last four days of the study break. We analyzed the participants' wrist actigraphy data during these four days to examine intraindividual variability in sleep timing, duration and efficiency. We also examined shifts in the DLMO from before and after the study break. Under the same conditions, people with DSWPD had significantly more variable wake times and total sleep time than healthy controls (p ≤ 0.015). Intraindividual variability in sleep onset time and sleep efficiency was similar between the two groups (p ≥ 0.30). The DLMO was relatively stable across the study break, with only 11% of controls but 27% of DSWPDs showed more than a one hour shift in the DLMO. Only in the DSWPD sample was greater sleep variability associated with a larger shift in the DLMO (r = 0.46, p = 0.03). These results suggest that intraindividual variability in sleep can be higher in DSWPD versus healthy controls, and this may impact variability in the DLMO. DSWPD patients with higher intraindividual variability in sleep are more likely to have a shifting DLMO, which could impact sleep symptoms and the optimal timing of light and/or melatonin treatment for DSWPD. Circadian Phase Assessments at Home, http://clinicaltrials.gov/show/NCT01487252, NCT01487252. Copyright © 2017 Elsevier B.V. All rights reserved.

The effects of sleep extension on the athletic performance of collegiate basketball players.

PubMed

Mah, Cheri D; Mah, Kenneth E; Kezirian, Eric J; Dement, William C

2011-07-01

To investigate the effects of sleep extension over multiple weeks on specific measures of athletic performance as well as reaction time, mood, and daytime sleepiness. Stanford Sleep Disorders Clinic and Research Laboratory and Maples Pavilion, Stanford University, Stanford, CA. Eleven healthy students on the Stanford University men's varsity basketball team (mean age 19.4 ± 1.4 years). Subjects maintained their habitual sleep-wake schedule for a 2-4 week baseline followed by a 5-7 week sleep extension period. Subjects obtained as much nocturnal sleep as possible during sleep extension with a minimum goal of 10 h in bed each night. Measures of athletic performance specific to basketball were recorded after every practice including a timed sprint and shooting accuracy. Reaction time, levels of daytime sleepiness, and mood were monitored via the Psychomotor Vigilance Task (PVT), Epworth Sleepiness Scale (ESS), and Profile of Mood States (POMS), respectively. Total objective nightly sleep time increased during sleep extension compared to baseline by 110.9 ± 79.7 min (P < 0.001). Subjects demonstrated a faster timed sprint following sleep extension (16.2 ± 0.61 sec at baseline vs. 15.5 ± 0.54 sec at end of sleep extension, P < 0.001). Shooting accuracy improved, with free throw percentage increasing by 9% and 3-point field goal percentage increasing by 9.2% (P < 0.001). Mean PVT reaction time and Epworth Sleepiness Scale scores decreased following sleep extension (P < 0.01). POMS scores improved with increased vigor and decreased fatigue subscales (P < 0.001). Subjects also reported improved overall ratings of physical and mental well-being during practices and games. Improvements in specific measures of basketball performance after sleep extension indicate that optimal sleep is likely beneficial in reaching peak athletic performance.

Sleep and Circadian Variability in People with Delayed Sleep-Wake Phase Disorder versus Healthy Controls

PubMed Central

Burgess, Helen J.; Park, Margaret; Wyatt, James K.; Rizvydeen, Muneer; Fogg, Louis F.

2017-01-01

Objective/Background To compare sleep and circadian variability in adults with delayed sleep-wake phase disorder (DSWPD) to healthy controls. Patients/Methods Forty participants (22 DSWPD, 18 healthy controls) completed a 10-day protocol, consisting of DLMO assessments on two consecutive nights, a five-day study break, followed by two more DLMO assessments. All participants were instructed to sleep within one hour of their self-reported average sleep schedule for the last four days of the study break. We analyzed the participants’ wrist actigraphy data during these four days to examine intraindividual variability in sleep timing, duration and efficiency. We also examined shifts in the DLMO from before and after the study break. Results and Conclusions Under the same conditions, people with DSWPD had significantly more variable wake times and total sleep time than healthy controls (p≤0.015). Intraindividual variability in sleep onset time and sleep efficiency was similar between the two groups (p≥0.30). The DLMO was relatively stable across the study break, with only 11% of controls but 27% of DSWPDs showed more than a one hour shift in the DLMO. Only in the DSWPD sample was greater sleep variability associated with a larger shift in the DLMO (r=0.46, p=0.03). These results suggest that intraindividual variability in sleep can be higher in DSWPD versus healthy controls, and this may impact variability in the DLMO. DSWPD patients with higher intraindividual variability in sleep are more likely to have a shifting DLMO, which could impact sleep symptoms and the optimal timing of light and/or melatonin treatment for DSWPD. PMID:28522096

A qualitative study of sleep quality in children and their resident parents when in hospital.

PubMed

Stickland, Alice; Clayton, Esther; Sankey, Ruth; Hill, Catherine M

2016-06-01

Poor sleep quality impairs immune responses and pain tolerance, both key to recovery from acute illness. Hospitalised children and their co-sleeping parents also risk emotional lability and impaired coping skills when sleep-deprived. We aimed to study the experiences of children and parents during hospital admissions. Semi-structured interviews were conducted with parents within a week of their child's discharge. Questions explored parent and child sleep quality, factors contributing to this, perceived impact on day-time functioning and suggested improvements to ward sleep environment. Southampton Children's Hospital, UK. 17 co-sleeping parents of 16 children aged 3-12 years completed interviews. Children admitted for surgical procedures and those with established sleep disorders or nocturnal seizures were excluded. Constant comparative methods identified themes within the data using a grounded theory approach. Parents reported that they, and to a lesser extent their children, experienced reduced sleep quality. Noise and light as well as ward schedules were identified as key factors disrupting sleep. Parents reported that lack of sleep caused difficulties with their own emotional regulation and that of their child, affecting daytime parent-child relationships. Furthermore, they reported a negative impact of sleep deprivation on decision-making about their child's medical care. Parents identified poor sleep in hospital as a significant additional burden to their child's hospital admission. Importantly, they identified potential improvements to the ward sleep environment. Intervention studies that target modifiable, child-centred alterations to night-time ward culture are recommended, focusing on measurable child and parental outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Commuting and Sleep: Results From the Hispanic Community Health Study/Study of Latinos Sueño Ancillary Study.

PubMed

Petrov, Megan E; Weng, Jia; Reid, Kathryn J; Wang, Rui; Ramos, Alberto R; Wallace, Douglas M; Alcantara, Carmela; Cai, Jianwen; Perreira, Krista; Espinoza Giacinto, Rebeca A; Zee, Phyllis C; Sotres-Alvarez, Daniela; Patel, Sanjay R

2018-03-01

Commute time is associated with reduced sleep time, but previous studies have relied on self-reported sleep assessment. The present study investigated the relationships between commute time for employment and objective sleep patterns among non-shift working U.S. Hispanic/Latino adults. From 2010 to 2013, Hispanic/Latino employed, non-shift-working adults (n=760, aged 18-64 years) from the Sueño study, ancillary to the Hispanic Community Health Study/Study of Latinos, reported their total daily commute time to and from work, completed questionnaires on sleep and other health behaviors, and wore wrist actigraphs to record sleep duration, continuity, and variability for 1 week. Survey linear regression models of the actigraphic and self-reported sleep measures regressed on categorized commute time (short: 1-44 minutes; moderate: 45-89 minutes; long: ≥90 minutes) were built adjusting for relevant covariates. For associations that suggested a linear relationship, continuous commute time was modeled as the exposure. Moderation effects by age, sex, income, and depressive symptoms also were explored. Commute time was linearly related to sleep duration on work days such that each additional hour of commute time conferred 15 minutes of sleep loss (p=0.01). Compared with short commutes, individuals with moderate commutes had greater sleep duration variability (p=0.04) and lower interdaily stability (p=0.046, a measure of sleep/wake schedule regularity). No significant associations were detected for self-reported sleep measures. Commute time is significantly associated with actigraphy-measured sleep duration and regularity among Hispanic/Latino adults. Interventions to shorten commute times should be evaluated to help improve sleep habits in this minority population. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Rapid eye movement sleep debt accrues in mice exposed to volatile anesthetics

PubMed Central

Pick, Jeremy; Chen, Yihan; Moore, Jason T.; Sun, Yi; Wyner, Abraham J.; Friedman, Eliot B.; Kelz, Max B.

2011-01-01

Background General anesthesia has been likened to a state in which anesthetized subjects are locked out of access to both rapid eye movement (REM) sleep and wakefulness. Were this true for all anesthetics, one might expect a significant REM rebound following anesthetic exposure. However, for the intravenous anesthetic propofol, studies demonstrate that no sleep debt accrues. Moreover, pre-existing sleep debts dissipate during propofol anesthesia. To determine whether these effects are specific to propofol or are typical of volatile anesthetics we tested the hypothesis that REM sleep debt would accrue in rodents anesthetized with volatile anesthetics. Methods Electroencephalographic and electromyographic electrodes were implanted in 10 mice. After 9–11 days of recovery and habituation to a 12h:12h light:dark cycle, baseline states of wakefulness, non-rapid eye movement sleep, and REM sleep were recorded in mice exposed to 6 hours of an oxygen control and on separate days to 6 hours of isoflurane, sevoflurane, or halothane in oxygen. All exposures were conducted at the onset of light. Results Mice in all three anesthetized groups exhibited a significant doubling of REM sleep during the first six-hours of the dark phase of the circadian schedule while only mice exposed to halothane displayed a significant increase in non-rapid eye movement sleep that peaked at 152% of baseline. Conclusion REM sleep rebound following exposure to volatile anesthetics suggests that these volatile anesthetics do not fully substitute for natural sleep. This result contrasts with the published actions of propofol for which no REM sleep rebound occurred. PMID:21934405

Parkinsonian syndromes presenting with circadian rhythm sleep disorder- advanced sleep-phase type.

PubMed

Shukla, Garima; Kaul, Bhavna; Gupta, Anupama; Goyal, Vinay; Behari, Madhuri

2015-01-01

Circadian rhythm sleep disorder-advanced sleep-phase type is a relatively uncommon disorder, mostly seen among the elderly population. Impaired circadian rhythms have been reported in neurodegenerative conditions; however, there are no reports of any circadian rhythm sleep disorder among patients with Parkinsonian syndromes. We report two patients who presented with this circadian rhythm disorder, and were then diagnosed with a Parkinsonian syndrome. The cases. A 65-year-old retired man presented with history of abrupt change in sleep schedules, sleeping around 6.30-7 p.m. and waking up around 3-4 a.m. for the last 2 months. On detailed examination, the patient was observed to have symmetrical bradykinesia and cogwheel rigidity of limbs. A diagnosis of multiple system atrophy was made, supported by MRI findings and evidence of autonomic dysfunction. Symptoms of change in sleep-wake cycles resolved over the next 1 year, while the patient was treated with dopaminergic therapy. A 47-year-old man, who was being evaluated for presurgical investigation for refractory temporal lobe epilepsy, presented with complaints suggestive of dysarthria, bradykinesia of limbs and frequent falls for 5 months. Simultaneously, he began to sleep around 7 p.m. and wake up at about 2-3 a.m. Examination revealed severe axial rigidity, restricted vertical gaze and bradykinesia of limbs. A diagnosis of progressive supranuclear palsy was made. This is the first report of Parkinson's plus syndromes presenting with a circadian rhythm sleep disorder-advanced sleep-phase type. More prospective assessment for circadian sleep disorders may introduce useful insights into similar associations. Copyright 2015, NMJI.

Out Like a Light? The Effects of a Diurnal Husbandry Schedule on Mouse Sleep and Behavior.

PubMed

Robinson-Junker, Amy L; O'hara, Bruce F; Gaskill, Brianna N

2018-03-01

Sleep disruption in humans, caused by shift work, can be detrimental to physical and behavioral health. Nocturnal laboratory mice may experience a similar disruption caused by human daytime activities, but whether this disruption affects their welfare is unknown. We used 48 mice (CD1, C57BL/6, and BALB/c of both sexes) in a factorial design to test a sleep disruption treatment, in which mice were disturbed by providing routine husbandry at either 1000 or 2200 during a 12:12-h light:dark cycle, with lights on at 0700. All mice were exposed for 1 wk to each disruption treatment, and we used a noninvasive sleep monitoring apparatus to monitor and record sleep. To determine whether providing nesting material ameliorated effects of sleep disruption, we tested 4 amounts of nesting material (3, 6, 9, or 12 g) and continuously recorded sleep in the home cage for 2 wk. C57BL/6 mice, regardless of sex or disruption timing, slept the least overall. There was a strong interaction of sex and type of mouse on sleep across 24 h. Mice slept less during the first day of the daytime disturbance than on day 6. These results suggest that disturbance timing affects sleep patterns in mice but not their overall amount of sleep and that the changes in sleep patterns vary between mouse type and sex. In addition, mice appear to both anticipate and acclimate to human activity during the day. Our welfare checks were possibly too predictable and inconsequential to induce true sleep disruption.

Role of the melatonin system in the control of sleep: therapeutic implications.

PubMed

Pandi-Perumal, Seithikurippu R; Srinivasan, Venkatramanujan; Spence, D Warren; Cardinali, Daniel P

2007-01-01

The circadian rhythm of pineal melatonin secretion, which is controlled by the suprachiasmatic nucleus (SCN), is reflective of mechanisms that are involved in the control of the sleep/wake cycle. Melatonin can influence sleep-promoting and sleep/wake rhythm-regulating actions through the specific activation of MT(1) (melatonin 1a) and MT(2) (melatonin 1b) receptors, the two major melatonin receptor subtypes found in mammals. Both receptors are highly concentrated in the SCN. In diurnal animals, exogenous melatonin induces sleep over a wide range of doses. In healthy humans, melatonin also induces sleep, although its maximum hypnotic effectiveness, as shown by studies of the timing of dose administration, is influenced by the circadian phase. In both young and elderly individuals with primary insomnia, nocturnal plasma melatonin levels tend to be lower than those in healthy controls. There are data indicating that, in affected individuals, melatonin therapy may be beneficial for ameliorating insomnia symptoms. Melatonin has been successfully used to treat insomnia in children with attention-deficit hyperactivity disorder or autism, as well as in other neurodevelopmental disorders in which sleep disturbance is commonly reported. In circadian rhythm sleep disorders, such as delayed sleep-phase syndrome, melatonin can significantly advance the phase of the sleep/wake rhythm. Similarly, among shift workers or individuals experiencing jet lag, melatonin is beneficial for promoting adjustment to work schedules and improving sleep quality. The hypnotic and rhythm-regulating properties of melatonin and its agonists (ramelteon, agomelatine) make them an important addition to the armamentarium of drugs for treating primary and secondary insomnia and circadian rhythm sleep disorders.

Sleep quality and quality of life in female shift-working nurses.

PubMed

Shao, Ming-Fen; Chou, Yu-Ching; Yeh, Mei-Yu; Tzeng, Wen-Chii

2010-07-01

This paper is a report of a study of the factors that influence sleep quality and quality of life among shift-working nurses and the relationship between their sleep quality and quality of life. Although shift-working nurses strive to adapt their life schedules to shift rotations, they tend to suffer from severe sleep disturbances and increased rates of cancer, cardiovascular diseases, digestive disease and irregular menstrual cycles. Poor sleep is also associated with medical errors and occupational injuries. A cross-sectional study was conducted in 2008 with a convenience sample of 435 female nurses from five regional hospitals in Taiwan. Data were collected on sleep quality and quality of life using the Pittsburgh Sleep Quality Index and World Health Organization Quality of Life Instrument-BREF Taiwan version respectively. Data were analysed using descriptive statistics, independent t-tests, analysis of variance and Pearson correlations. The majority of female shift workers (57%) had global sleep-quality scores > or = 5, indicating poor sleep and all mean scores in four domains of the quality-of-life measure were statistically significantly lower than those of females in Taiwan's general population. Scores for poor sleep quality and quality of life were related to premenstrual dysphoria, occupational injury, illness and medication use. In addition, the associations between scores on the sleep-quality and quality-of-life scales were statistically significantly inversely correlated. Advice should be included in both undergraduate programmes and continuing education to help nurses to recognize and improve their own sleep quality and life quality managers should create a supportive environment to encourage shift-working nurses to engage in healthy behaviours.

The Effects of Acute Sleep Restriction on Adolescents' Pedestrian Safety in a Virtual Environment

PubMed Central

Davis, Aaron L.; Avis, Kristin T.; Schwebel, David C.

2013-01-01

Purpose Over 8,000 American adolescents ages 14-15 require medical attention due to pedestrian injury annually. Cognitive factors contributing to pedestrian safety include reaction time, impulsivity, risk-taking, attention, and decision-making. These characteristics are also influenced by sleep restriction. Experts recommend adolescents obtain 8.5 hours of uninterrupted sleep each night, but most American adolescents do not. Inadequate sleep may place adolescents at risk for pedestrian injury. Method Using a within-subjects design, fifty-five 14- and 15-year-olds engaged in a virtual reality pedestrian environment in two conditions, scheduled a week apart: sleep-restricted (4 hours sleep previous night) and adequate sleep (8.5 hours). Sleep was assessed using actigraphy and pedestrian behavior via four outcome measures: time to initiate crossing, time before contact with vehicle while crossing, virtual hits/close calls and attention to traffic (looks left and right). Results While acutely sleep restricted, adolescents took more time to initiate pedestrian crossings, crossed with less time before contact with vehicles, experienced more virtual hits/close calls and looked left and right more often compared to when adequately rested. Results were maintained after controlling for age, gender, ethnicity and average total sleep duration prior to each condition. Discussion Adolescent pedestrian behavior in the simulated virtual environment was markedly different, and generally more risky, when acutely sleep restricted compared to adequately rested. Inadequate sleep may influence cognitive functioning to the extent that pedestrian safety is jeopardized among adolescents capable of crossing streets safely when rested. Policy decisions might be educated by these results. PMID:24012066

Risk of Performance Decrements and Adverse Health Outcomes Resulting from Sleep Loss, Circadian Desynchronization, and Work Overload

NASA Technical Reports Server (NTRS)

Flynn-Evans, Erin; Gregory, Kevin; Arsintescu, Lucia; Whitmire, Alexandra

2016-01-01

Sleep loss, circadian desynchronization, and work overload occur to some extent for ground and flight crews, prior to and during spaceflight missions. Ground evidence indicates that such risk factors may lead to performance decrements and adverse health outcomes, which could potentially compromise mission objectives. Efforts are needed to identify the environmental and mission conditions that interfere with sleep and circadian alignment, as well as individual differences in vulnerability and resiliency to sleep loss and circadian desynchronization. Specifically, this report highlights a collection of new evidence to better characterize the risk and reveals new gaps in this risk as follows: Sleep loss is apparent during spaceflight. Astronauts consistently average less sleep during spaceflight relative to on the ground. The causes of this sleep loss remain unknown, however ground-based evidence suggests that the sleep duration of astronauts is likely to lead to performance impairment and short and long-term health consequences. Further research is needed in this area in order to develop screening tools to assess individual astronaut sleep need in order to quantify the magnitude of sleep loss during spaceflight; current and planned efforts in BHP's research portfolio address this need. In addition, it is still unclear whether the conditions of spaceflight environment lead to sleep loss or whether other factors, such as work overload lead to the reduced sleep duration. Future data mining efforts and continued data collection on the ISS will help to further characterize factors contributing to sleep loss. Sleep inertia has not been evaluated during spaceflight. Ground-based studies confirm that it takes two to four hours to achieve optimal performance after waking from a sleep episode. Sleep inertia has been associated with increased accidents and reduced performance in operational environments. Sleep inertia poses considerable risk during spaceflight when emergency situations necessitate that crewmembers wake from sleep and make quick decisions. A recently completed BHP investigation assesses the effects of sleep inertia upon abrupt awakening, with and without hypnotics currently used in spaceflight; results from this investigation will help to inform strategies relative to sleep inertia effects on performance. Circadian desynchrony has been observed during spaceflight. Circadian desynchrony during spaceflight develops due to schedule constraints requiring non-24 operations or 'slam-shifts' and due to insufficient or mis-timed light exposure. In addition, circadian misalignment has been associated with reduced sleep duration and increased medication use. In ground-based studies, circadian desynchrony has been associated with significant performance impairment and increased risk of accidents when operations coincide with the circadian nadir. There is a great deal of information available on how to manage circadian misalignment, however, there are currently no easily collected biomarkers that can be used during spaceflight to determine circadian phase. Current research efforts are addressing this gap. Work overload has been documented during current spaceflight operations. NASA has established work hour guidelines that limit shift duration, however, schedule creep, where duty requirements necessitate working beyond scheduled work hours, has been reported. This observation warrants the documentation of actual work hours in order to improve planning and in order to ensure that astronauts receive adequate down time. In addition to concerns about work overload, ground based evidence suggests that work underload may be a concern during deep space missions, where torpor may develop and physically demanding workload will be exchanged for monitoring of autonomous systems. Given that increased automation is anticipated for exploration vehicles, fatigue effects in the context of such systems needs to be further understood. Performance metrics are needed to evaluate fitness-for-duty during spaceflight. Although ground-based evidence supports the notion that sleep loss, circadian desynchronization and work overload lead to performance impairment, inconsistency in the measures used to evaluate performance during spaceflight make it difficult to evaluate the magnitude of performance impairment during spaceflight. Work is underway to standardize measures of performance evaluation during spaceflight. Once established, such performance indicators need to be correlated with operational performance. Individual differences in sleep need and circadian preference, phase shifting ability and period have been documented in ground-based studies. Individual differences in response to sleep loss and circadian misalignment have also been documented and are presumed to be associated with genetic polymorphisms. No studies have systematically reported individual differences in sleep or circadian-related outcomes during spaceflight. More work is needed in this area in order to identify genetic or phenotypic biomarkers that predict resilience or vulnerability to sleep loss in order to personalize countermeasure strategies and mitigate performance impairment during spaceflight. Two laboratory and field investigations specific to this topic are currently ongoing; additional efforts, including an effort to mine existing biological data from spaceflight relative to sleep and circadian outcomes, are planned. Sex differences in sleep need and circadian period and phase have been reported in ground-based studies. The impact of these sex differences on performance is unclear. Sex differences in sleep need and circadian rhythms have not been systematically studied during spaceflight, presumably due to the small number of women that have flown in space. More research is needed in this area to evaluate whether any of the observed sex differences in physiology lead to altered performance in spaceflight and on the ground.

No difference in self reported health among coalminers in two different shift schedules at Spitsbergen, Norway, a two years follow-up.

PubMed

Hanoa, Rolf; Baste, Valborg; Kooij, Arne; Sommervold, Linda; Moen, Bente Elisabeth

2011-01-01

This study was performed among coal miners in the remote location Svea, Spitsbergen. The shift schedule used to be 7 d on and 7 d off. The aim of this study was to investigate possible changes in health after a voluntary implementation of a new shift schedule, with periods of 14 d on and 14 d off, for 74 percent of the workers in 2007. A questionnaire was distributed to all employees before and two times after the new shift schedule, comprising questions on type of work, shift schedule, pain, sleep, stress and coping. Ninety nine percent of the employees responded; 274 in 2006, 307 in 2007 and 312 in 2008. Work neither in the 14/14 shift nor 7/7 shift was related to any change in the health after these two years. The coping index for workers in the 14/14 shift improved.

Daily morning running for 3 weeks improved sleep and psychological functioning in healthy adolescents compared with controls.

PubMed

Kalak, Nadeem; Gerber, Markus; Kirov, Roumen; Mikoteit, Thorsten; Yordanova, Juliana; Pühse, Uwe; Holsboer-Trachsler, Edith; Brand, Serge

2012-12-01

To compare sleep electroencephalographic patterns and psychological functioning of healthy adolescents running regularly in the mornings with those of control subjects. Although several studies have shown that regular moderate-to-vigorous exercise is related to favorable sleep and psychological functioning in adolescents, research on the effectiveness of short interventions is more limited. Fifty-one adolescents (mean age = 18.30 years; 27 female [53%]) took part in the study; they were randomly assigned either to a running or to a control group. The running group went running every morning for 30 minutes at moderate intensity during weekdays for 3 consecutive weeks. Sleep electroencephalographic patterns and psychological functioning were assessed in both groups before and after the 3-week period. All participants also kept a sleep log for 3 weeks. Objective sleep improved (slow-wave sleep increased; sleep onset latency decreased) in the running group compared with the control group. Subjective sleep quality, mood, and concentration during the day improved, whereas sleepiness during the day decreased. Thirty minutes of running in the morning during weekdays for 3 consecutive weeks impacted positively on sleep and psychological functioning in healthy adolescents compared with control subjects. Running is inexpensive and easy to implement during school schedules, and as both objective and subjective improvements were observed within 3 weeks, regular physical exercise should be promoted. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Is Inconsistent Pre-treatment Bedtime Related to CPAP Non-Adherence?

PubMed Central

Sawyer, Amy M.; King, Tonya S.; Sawyer, Douglas A.; Rizzo, Albert

2014-01-01

Lack of adherence to continuous positive airway pressure therapy (CPAP) limits the effectiveness of treatment of obstructive sleep apnea (OSA). We hypothesized that an irregular bedtime would be negatively related to regular use of CPAP treatment. If so, modifying bedtime schedule may address the persistent problem of inconsistent CPAP use in adults with OSA. In a prospective longitudinal study, we examined whether inconsistent self-reported bedtime before initiation of CPAP treatment, operationalized as bedtime variability, was (1) different among those adherent (≥ 4 hours per night) and non-adherent to CPAP treatment at one week and one month; and/or (2) was related to one-week and one-month CPAP use when other variables were accounted for. Consecutively-recruited newly-diagnosed OSA adults (N=79) completed sleep diaries prior to CPAP treatment. One-week and one-month objective CPAP use data were collected. Pre-treatment bedtime variability was different among CPAP non-adherers and adherers at one month and was a significant predictor of non-adherence at one month in multivariate analyses. The odds of one-month CPAP non-adherence were 3.5 times greater in those whose pre-treatment bedtimes varied by >75 minutes. Addressing sleep schedule prior to CPAP initiation may be an opportunity to improve CPAP adherence. PMID:25353159

Effect of a Protected Sleep Period on Hours Slept During Extended Overnight In-hospital Duty Hours Among Medical Interns

PubMed Central

Volpp, Kevin G.; Shea, Judy A.; Small, Dylan S.; Basner, Mathias; Zhu, Jingsan; Norton, Laurie; Ecker, Adrian; Novak, Cristina; Bellini, Lisa M.; Dine, C. Jessica; Mollicone, Daniel J.; Dinges, David F.

2013-01-01

Context A 2009 Institute of Medicine report recommended protected sleep periods for medicine trainees on extended overnight shifts, a position reinforced by new Accreditation Council for Graduate Medical Education requirements. Objective To evaluate the feasibility and consequences of protected sleep periods during extended duty. Design, Setting, and Participants Randomized controlled trial conducted at the Philadelphia VA Medical Center medical service and Oncology Unit of the Hospital of the University of Pennsylvania (2009–2010). Of the 106 interns and senior medical students who consented, 3 were not scheduled on any study rotations. Among the others, 44 worked at the VA center, 16 at the university hospital, and 43 at both. Intervention Twelve 4-week blocks were randomly assigned to either a standard intern schedule (extended duty overnight shifts of up to 30 hours; equivalent to 1200 overnight intern shifts at each site), or a protected sleep period (protected time from 12:30 AM to 5:30 AM with handover of work cell phone; equivalent to 1200 overnight intern shifts at each site). Participants were asked to wear wrist actigraphs and complete sleep diaries. Main Outcome Measures Primary outcome was hours slept during the protected period on extended duty overnight shifts. Secondary outcome measures included hours slept during a 24-hour period (noon to noon) by day of call cycle and Karolinska sleepiness scale. Results For 98.3% of on-call nights, cell phones were signed out as designed. At the VA center, participants with protected sleep had a mean 2.86 hours (95% CI, 2.57–3.10 hours) of sleep vs 1.98 hours (95% CI, 1.68–2.28 hours) among those who did not have protected hours of sleep (P < .001). At the university hospital, participants with protected sleep had a mean 3.04 hours (95% CI, 2.77–3.45 hours) of sleep vs 2.04 hours (95% CI, 1.79–2.24) among those who did not have protected sleep (P <.001). Participants with protected sleep were significantly less likely to have call nights with no sleep: 5.8% (95% CI, 3.0%–8.5%) vs 18.6% (95% CI, 13.9%–23.2%) at the VA center (P <.001) and 5.9% (95% CI, 3.1%–8.7%) vs 14.2% (95% CI, 9.9%–18.4%) at the university hospital (P=.001). Participants felt less sleepy after on-call nights in the intervention group, with Karolinska sleepiness scale scores of 6.65 (95% CI, 6.35–6.97) vs 7.10 (95% CI, 6.85–7.33; P=.01) at the VA center and 5.91 (95% CI, 5.64–6.16) vs 6.79 (95% CI, 6.57–7.04; P <.001) at the university hospital. Conclusions For internal medicine services at 2 hospitals, implementation of a protected sleep period while on call resulted in an increase in overnight sleep duration and improved alertness the next morning. Trial Registration clinicaltrials.gov Identifier: NCT00874510. PMID:23212498

Sleep Moderates the Association Between Response Inhibition and Self-Regulation in Early Childhood

PubMed Central

Schumacher, Allyson M.; Miller, Alison L.; Watamura, Sarah E.; Kurth, Salome; Lassonde, Jonathan M.; LeBourgeois, Monique K.

2017-01-01

Early childhood is a time of rapid developmental changes in sleep, cognitive control processes, and the regulation of emotion and behavior. This experimental study examined sleep-dependent effects on response inhibition and self-regulation, as well as whether acute sleep restriction moderated the association between these processes. Preschool children (N = 19; 45.6 ± 2.2 months; 11 female) followed a strict sleep schedule for at least 3 days before each of 2 morning behavior assessments: baseline (habitual nap/night sleep) and sleep restriction (missed nap/delayed bedtime). Response inhibition was evaluated via a go/no-go task. Twelve self-regulation strategies were coded from videotapes of children while attempting an unsolvable puzzle. We then created composite variables representing adaptive and maladaptive self-regulation strategies. Although we found no sleep-dependent effects on response inhibition or self-regulation measures, linear mixed-effects regression showed that acute sleep restriction moderated the relationship between these processes. At baseline, children with better response inhibition were more likely to use adaptive self-regulation strategies (e.g., self-talk, alternate strategies), and those with poorer response inhibition showed increased use of maladaptive self-regulation strategies (e.g., perseveration, fidgeting); however, response inhibition was not related to self-regulation strategies following sleep restriction. Our results showing a sleep-dependent effect on the associations between response inhibition and self-regulation strategies indicate that adequate sleep facilitates synergy between processes supporting optimal social-emotional functioning in early childhood. Although replication studies are needed, findings suggest that sleep may alter connections between maturing emotional and cognitive systems, which have important implications for understanding risk for or resilience to developmental psychopathology. PMID:27652491

Time course of sleep inertia dissipation in human performance and alertness

NASA Technical Reports Server (NTRS)

Jewett, M. E.; Wyatt, J. K.; Ritz-De Cecco, A.; Khalsa, S. B.; Dijk, D. J.; Czeisler, C. A.

1999-01-01

Alertness and performance on a wide variety of tasks are impaired immediately upon waking from sleep due to sleep inertia, which has been found to dissipate in an asymptotic manner following waketime. It has been suggested that behavioural or environmental factors, as well as sleep stage at awakening, may affect the severity of sleep inertia. In order to determine the time course of sleep inertia dissipation under normal entrained conditions, subjective alertness and cognitive throughput were measured during the first 4 h after habitual waketime from a full 8-h sleep episode on 3 consecutive days. We investigated whether this time course was affected by either sleep stage at awakening or behavioural/environmental factors. Sleep inertia dissipated in an asymptotic manner and took 2-4 h to near the asymptote. Saturating exponential functions fitted the sleep inertia data well, with time constants of 0.67 h for subjective alertness and 1.17 h for cognitive performance. Most awakenings occurred out of stage rapid eye movement (REM), 2 or 1 sleep, and no effect of sleep stage at awakening on either the severity of sleep inertia or the time course of its dissipation could be detected. Subjective alertness and cognitive throughput were significantly impaired upon awakening regardless of whether subjects got out of bed, ate breakfast, showered and were exposed to ordinary indoor room light (approximately 150 lux) or whether subjects participated in a constant routine (CR) protocol in which they remained in bed, ate small hourly snacks and were exposed to very dim light (10-15 lux). These findings allow for the refinement of models of alertness and performance, and have important implications for the scheduling of work immediately upon awakening in many occupational settings.

Latino Parents' Insight on Optimal Sleep for Their Preschool-Age Child: Does Context Matter?

PubMed

Martinez, Suzanna M; Thompson-Lastad, Ariana

2015-01-01

Insufficient sleep is a risk factor for pediatric obesity. Latino children are among those groups in which both short sleep duration and obesity are prevalent. Therefore, this study sought to explore Latino parents' views about ideal sleep duration and sleep-related practices for their preschool-age children in an urban setting. Between October 2013 and January 2014, Latino parents of 2- to 5-year-old children were interviewed at 3 pediatric clinics (San Francisco, Calif). Using a semistructured interview guide, parents were asked to describe bedtime routines and sleep practices of their preschool-age children, including behavioral, parental, social, and contextual factors that may affect children's sleep. Interviews were conducted in Spanish and English. Parents also completed a brief survey on demographic information. Interviews were analyzed on the basis of a priori and emergent themes. Latino parents (n = 18) were mostly female, with a mean age of 31 years; most were foreign born; and more than half had a monthly household income of $2000 or less. The following themes emerged: parents' ideas about optimal sleep duration for their preschool-age child, consistent bedtime routines, room sharing and bed sharing, parent work and child school schedules that affect children's sleep, and crowded housing and neighborhood noise that disrupt children's sleep. These findings increase our understanding of the factors related to achieving optimal sleep duration among Latino children living in urban and often crowded housing. Findings could be used to inform future research on how to increase parental knowledge of healthy sleep practices and adequate sleep among Latino parents of young children. Copyright © 2015 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Bullying, sleep/wake patterns and subjective sleep disorders: findings from a cross-sectional survey.

PubMed

Kubiszewski, Violaine; Fontaine, Roger; Potard, Catherine; Gimenes, Guillaume

2014-05-01

The aim of this study was to explore: (a) sleep patterns and disorders possibly associated with adolescent bullying profiles (pure bully, pure victim, bully/victim and neutral) and (b) the effect of sleep on psychosocial problems (externalized and internalized) related to bullying. The sample consisted of 1422 students aged 10-18 (mean = 14.3, SD = 2.7; 57% male) from five socioeconomically diverse schools in France. Bullying profiles were obtained using the revised Bully-Victim Questionnaire. Subjective sleep disorders were assessed using the Athens Insomnia Scale. School-week and weekend sleep/wake patterns were recorded. Internalizing problems were investigated using a Perceived Social Disintegration Scale and a Psychological Distress Scale. Externalizing behaviors were assessed using a General Aggressiveness Scale and an Antisocial Behavior Scale. These questionnaires were administered during individual interviews at school. After controlling for effects of gender and age, victims of bullying showed significantly more subjective sleep disturbances than the pure-bully or neutral groups (p < 0.001). Bullies' sleep schedules were more irregular (p < 0.001 for bedtime irregularity and p<0.01 for wake-up time irregularity) and their sleep duration was shorter than their schoolmates (p < 0.001 for the school week and p < 0.05 for the weekend). There was an effect of sleep on psychosocial problems related to bullying, and our results indicate that sleep has a moderating effect on aggression in bullies (p < 0.001). This would suggest a higher vulnerability of bullies to sleep deprivation. These results show differences in sleep problems and patterns in school-bullying profiles. Findings of this study open up new perspectives for understanding and preventing bullying in schools, with implications for research and clinical applications.

Diagnostic and Treatment Challenges of Sighted Non-24-Hour Sleep-Wake Disorder.

PubMed

Malkani, Roneil G; Abbott, Sabra M; Reid, Kathryn J; Zee, Phyllis C

2018-04-15

To report the diagnostic and treatment challenges of sighted non-24-hour sleep-wake disorder (N24SWD). We report a series of seven sighted patients with N24SWD clinically evaluated by history and sleep diaries, and when available wrist actigraphy and salivary melatonin levels, and treated with timed melatonin and bright light therapy. Most patients had a history of a delayed sleep-wake pattern prior to developing N24SWD. The typical sleep-wake pattern of N24SWD was seen in the sleep diaries (and in actigraphy when available) in all patients with a daily delay in midpoint of sleep ranging 0.8 to 1.8 hours. Salivary dim light melatonin onset (DLMO) was evaluated in four patients but was missed in one. The estimated phase angle from DLMO to sleep onset ranged from 5.25 to 9 hours. All six patients who attempted timed melatonin and bright light therapy were able to entrain their sleep-wake schedules. Entrainment occurred at a late circadian phase, possibly related to the late timing of melatonin administration, though the patients often preferred late sleep times. Most did not continue treatment and continued to have a non-24-hour sleep-wake pattern. N24SWD is a chronic debilitating disorder that is often overlooked in sighted people and can be challenging to diagnose and treat. Tools to assess circadian pattern and timing can be effectively applied to aid the diagnosis. The progressive delay of the circadian rhythm poses a challenge for determining the most effective timing for melatonin and bright light therapies. Furthermore, once the circadian sleep-wake rhythm is entrained, long-term effectiveness is limited because of the behavioral and environmental structure that is required to maintain stable entrainment. © 2018 American Academy of Sleep Medicine.

A single night of sleep loss impairs objective but not subjective working memory performance in a sex-dependent manner.

PubMed

Rångtell, Frida H; Karamchedu, Swathy; Andersson, Peter; Liethof, Lisanne; Olaya Búcaro, Marcela; Lampola, Lauri; Schiöth, Helgi B; Cedernaes, Jonathan; Benedict, Christian

2018-01-31

Acute sleep deprivation can lead to judgement errors and thereby increases the risk of accidents, possibly due to an impaired working memory. However, whether the adverse effects of acute sleep loss on working memory are modulated by auditory distraction in women and men are not known. Additionally, it is unknown whether sleep loss alters the way in which men and women perceive their working memory performance. Thus, 24 young adults (12 women using oral contraceptives at the time of investigation) participated in two experimental conditions: nocturnal sleep (scheduled between 22:30 and 06:30 hours) versus one night of total sleep loss. Participants were administered a digital working memory test in which eight-digit sequences were learned and retrieved in the morning after each condition. Learning of digital sequences was accompanied by either silence or auditory distraction (equal distribution among trials). After sequence retrieval, each trial ended with a question regarding how certain participants were of the correctness of their response, as a self-estimate of working memory performance. We found that sleep loss impaired objective but not self-estimated working memory performance in women. In contrast, both measures remained unaffected by sleep loss in men. Auditory distraction impaired working memory performance, without modulation by sleep loss or sex. Being unaware of cognitive limitations when sleep-deprived, as seen in our study, could lead to undesirable consequences in, for example, an occupational context. Our findings suggest that sleep-deprived young women are at particular risk for overestimating their working memory performance. © 2018 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

The Circadian System Contributes to Apnea Lengthening across the Night in Obstructive Sleep Apnea

PubMed Central

Butler, Matthew P.; Smales, Carolina; Wu, Huijuan; Hussain, Mohammad V.; Mohamed, Yusef A.; Morimoto, Miki; Shea, Steven A.

2015-01-01

Study Objective: To test the hypothesis that respiratory event duration exhibits an endogenous circadian rhythm. Design: Within-subject and between-subjects. Settings: Inpatient intensive physiologic monitoring unit at the Brigham and Women's Hospital. Participants: Seven subjects with moderate/severe sleep apnea and four controls, age 48 (SD = 12) years, 7 males. Interventions: Subjects completed a 5-day inpatient protocol in dim light. Polysomnography was recorded during an initial control 8-h night scheduled at the usual sleep time, then through 10 recurrent cycles of 2 h 40 min sleep and 2 h 40 min wake evenly distributed across all circadian phases, and finally during another 8-h control sleep period. Measurements and Results: Event durations, desaturations, and apnea-hypopnea index for each sleep opportunity were assessed according to circadian phase (derived from salivary melatonin), time into sleep, and sleep stage. Average respiratory event durations in NREM sleep significantly lengthened across both control nights (21.9 to 28.2 sec and 23.7 to 30.2 sec, respectively). During the circadian protocol, event duration in NREM increased across the circadian phases that corresponded to the usual sleep period, accounting for > 50% of the increase across normal 8-h control nights. AHI and desaturations were also rhythmic: AHI was highest in the biological day while desaturations were greatest in the biological night. Conclusions: The endogenous circadian system plays an important role in the prolongation of respiratory events across the night, and might provide a novel therapeutic target for modulating sleep apnea. Citation: Butler MP, Smales C, Wu H, Hussain MV, Mohamed YA, Morimoto M, Shea SA. The circadian system contributes to apnea lengthening across the night in obstructive sleep apnea. SLEEP 2015;38(11):1793–1801. PMID:26039970

Shorter sleep duration is associated with social impairment and comorbidities in ASD.

PubMed

Veatch, Olivia J; Sutcliffe, James S; Warren, Zachary E; Keenan, Brendan T; Potter, Melissa H; Malow, Beth A

2017-07-01

Sleep disturbance, particularly insomnia, is common in children with autism spectrum disorders (ASD). Furthermore, disturbed sleep affects core symptoms and other related comorbidities. Understanding the causes and consequences of sleep disturbances in children with ASD is an important step toward mitigating these symptoms. To better understand the connection between sleep duration and ASD severity, we analyzed ASD-related symptoms using the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule (ADOS), IQ scores, and parent reports of the average amount of time slept per night that were available in the medical histories of 2,714 children with ASD in the Simons Simplex Collection (SSC). The mean (SD) sleep duration was 555 minutes. Sleep duration and severity of core ASD symptoms were negatively correlated, and sleep duration and IQ scores were positively correlated. Regression results indicated that more severe social impairment, primarily a failure to develop peer relationships, is the core symptom most strongly associated with short sleep duration. Furthermore, increased severity for numerous maladaptive behaviors assessed on the Child Behavior Checklist, as well as reports of attention deficit disorder, depressive disorder, and obsessive compulsive disorder were associated with short sleep duration. Severity scores for social/communication impairment and restricted and repetitive behaviors (RRB) were increased, and IQ scores were decreased, for children reported to sleep ≤420 minutes per night (lower 5th percentile) compared to children sleeping ≥660 minutes (upper 95th percentile). Our results indicate that reduced amounts of sleep are related to more severe symptoms in children with ASD. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1221-1238. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Digital sleep logs reveal potential impacts of modern temporal structure on class performance in different chronotypes.

PubMed

Smarr, Benjamin Lee

2015-02-01

Stability of sleep and circadian rhythms are important for healthy learning and memory. While experimental manipulations of lifestyle and learning outcomes present major obstacles, the ongoing increase in data sources allows retrospective data mining of people's sleep timing variation. Here I use digital sleep-log data generated by 1109 students in a biology lab course at the University of Washington to test the hypothesis that higher variance in time asleep and later sleep-onset times negatively correlate with class performance, used here as a real-world proxy for learning and memory. I find that sleep duration variance and mean sleep-onset times both significantly correlate with class performance. These correlations are powerful on weeknights but undetectable on Friday and Saturday nights ("free nights"). Finally, although these data come with no demographic information beyond sex, the constructed demographic groups of "larks" and "owls" within the sexes reveal a significant decrease in performance of owls relative to larks in male students, whereas the correlation of performance with sleep-onset time for all male students was only a near-significant trend. This provides a proof of concept that deeper demographic mining of digital logs in the future may identify subgroups for which certain sleep phenotypes have greater predictive value for performance outcomes. The data analyzed are consistent with known patterns, including sleep-timing delays from weeknights to free nights and sleep-timing delays in men relative to women. These findings support the hypothesis that modern schedule impositions on sleep and circadian timing have consequences for real-world learning and memory. This study also highlights the low-cost, large-scale benefits of personal, daily, digital records as an augmentation of sleep and circadian studies. © 2015 The Author(s).

Sleep patterns and habits in high school students in Iran

PubMed Central

Ghanizadeh, Ahmad; Kianpoor, Mohsen; Rezaei, Mehdi; Rezaei, Hadi; Moini, Rozita; Aghakhani, kamran; Ahmadi, Jamshid; Moeini, Seyed Reza

2008-01-01

Background Sleep patterns and habits in high school students in Iran have not been well studied to date. This paper aims to re-address this balance and analyse sleep patterns and habits in Iranian children of high school age. Methods The subjects were 1,420 high school students randomly selected by stratified cluster sampling. This was a self-report study using a questionnaire which included items about usual sleep/wake behaviours over the previous month, such as sleep schedule, falling asleep in class, difficulty falling asleep, tiredness or sleepiness during the day, difficulty getting up in the morning, nightmares, and taking sleeping pills. Results The mean duration of night sleep was 7.7 h, with no difference between girls, boys, and school year (grade). The mean time of waking in the morning was not different between genders. About 9.9% of the girls and 4.6% of the boys perceived their quality of sleep as being bad, and 58% of them reported sleepiness during the day. About 4.2% of the subjects had used medication to enhance sleep. The time of going to bed was associated with grade level and gender. Sleep latency was not associated with gender and grade leve, l and 1.4% experienced bruxism more than four times a week. Conclusion Our results are in contrast with that of previous studies that concluded sleep duration is shorter in Asia than in Europe, that boys woke-up significantly later than girls, and that the frequency of sleep latency category was associated with gender and grade level. The magnitude of the daytime sleepiness, daytime sleepiness during classes, sleep latency, and incidences of waking up at night represent major public health concerns for Iran. PMID:18339201

Sleep patterns and habits in high school students in Iran.

PubMed

Ghanizadeh, Ahmad; Kianpoor, Mohsen; Rezaei, Mehdi; Rezaei, Hadi; Moini, Rozita; Aghakhani, Kamran; Ahmadi, Jamshid; Moeini, Seyed Reza

2008-03-13

Sleep patterns and habits in high school students in Iran have not been well studied to date. This paper aims to re-address this balance and analyse sleep patterns and habits in Iranian children of high school age. The subjects were 1,420 high school students randomly selected by stratified cluster sampling. This was a self-report study using a questionnaire which included items about usual sleep/wake behaviours over the previous month, such as sleep schedule, falling asleep in class, difficulty falling asleep, tiredness or sleepiness during the day, difficulty getting up in the morning, nightmares, and taking sleeping pills. The mean duration of night sleep was 7.7 h, with no difference between girls, boys, and school year (grade). The mean time of waking in the morning was not different between genders. About 9.9% of the girls and 4.6% of the boys perceived their quality of sleep as being bad, and 58% of them reported sleepiness during the day. About 4.2% of the subjects had used medication to enhance sleep. The time of going to bed was associated with grade level and gender. Sleep latency was not associated with gender and grade level, l and 1.4% experienced bruxism more than four times a week. Our results are in contrast with that of previous studies that concluded sleep duration is shorter in Asia than in Europe, that boys woke-up significantly later than girls, and that the frequency of sleep latency category was associated with gender and grade level. The magnitude of the daytime sleepiness, daytime sleepiness during classes, sleep latency, and incidences of waking up at night represent major public health concerns for Iran.

Sleep Moderates the Association Between Response Inhibition and Self-Regulation in Early Childhood.

PubMed

Schumacher, Allyson M; Miller, Alison L; Watamura, Sarah E; Kurth, Salome; Lassonde, Jonathan M; LeBourgeois, Monique K

2017-01-01

Early childhood is a time of rapid developmental changes in sleep, cognitive control processes, and the regulation of emotion and behavior. This experimental study examined sleep-dependent effects on response inhibition and self-regulation, as well as whether acute sleep restriction moderated the association between these processes. Preschool children (N = 19; 45.6 ± 2.2 months; 11 female) followed a strict sleep schedule for at least 3 days before each of 2 morning behavior assessments: baseline (habitual nap/night sleep) and sleep restriction (missed nap/delayed bedtime). Response inhibition was evaluated via a go/no-go task. Twelve self-regulation strategies were coded from videotapes of children while attempting an unsolvable puzzle. We then created composite variables representing adaptive and maladaptive self-regulation strategies. Although we found no sleep-dependent effects on response inhibition or self-regulation measures, linear mixed-effects regression showed that acute sleep restriction moderated the relationship between these processes. At baseline, children with better response inhibition were more likely to use adaptive self-regulation strategies (e.g., self-talk, alternate strategies), and those with poorer response inhibition showed increased use of maladaptive self-regulation strategies (e.g., perseveration, fidgeting); however, response inhibition was not related to self-regulation strategies following sleep restriction. Our results showing a sleep-dependent effect on the associations between response inhibition and self-regulation strategies indicate that adequate sleep facilitates synergy between processes supporting optimal social-emotional functioning in early childhood. Although replication studies are needed, findings suggest that sleep may alter connections between maturing emotional and cognitive systems, which have important implications for understanding risk for or resilience to developmental psychopathology.

The effect of sleep restriction on snacking behaviour during a week of simulated shiftwork.

PubMed

Heath, Georgina; Roach, Gregory D; Dorrian, Jillian; Ferguson, Sally A; Darwent, David; Sargent, Charli

2012-03-01

Due to irregular working hours shiftworkers experience circadian disruption and sleep restriction. There is some evidence to indicate that these factors adversely affect health through changes in snacking behaviour. The aim of this study was to investigate the impact of sleep restriction, prior wake and circadian phase on snacking behaviour during a week of simulated shiftwork. Twenty-four healthy males (age: 22.0 ± 3.6 years, mean ± SD) lived in a sleep laboratory for 12 consecutive days. Participants were assigned to one of two schedules: a moderate sleep restriction condition (n=10) equivalent to a 6-h sleep opportunity per 24h or a severe sleep restriction condition (n=14) equivalent to a 4-h sleep opportunity per 24h. In both conditions, sleep/wake episodes occurred 4h later each day to simulate a rotating shiftwork pattern. While living in the laboratory, participants were served three meals and were provided with either five (moderate sleep restriction condition) or six (severe sleep restriction condition) snack opportunities daily. Snack choice was recorded at each opportunity and assigned to a category (sweet, savoury or healthy) based on the content of the snack. Data were analysed using a Generalised Estimating Equations approach. Analyses show a significant effect of sleep restriction condition on overall and sweet snack consumption. The odds of consuming a snack were significantly greater in the severe sleep restriction condition (P<0.05) compared to the moderate sleep restriction condition. In particular, the odds of choosing a sweet snack were significantly increased in the severe sleep restriction condition (P<0.05). Shiftworkers who are severely sleep restricted may be at risk of obesity and related health disorders due to elevated snack consumption and unhealthy snack choice. To further understand the impact of sleep restriction on snacking behaviour, future studies should examine physiological, psychological and environmental motivators. Copyright © 2011 Elsevier Ltd. All rights reserved.