Total sleep deprivation, chronic sleep restriction and sleep disruption

Sleep loss may result from total sleep deprivation (such as a shift worker might experience), chronic sleep restriction (due to work, medical conditions or lifestyle) or sleep disruption (which is common in sleep disorders such as sleep apnea or restless legs syndrome). Total sleep deprivation has been widely researched, and its effects have been well described. Chronic sleep restriction and sleep disruption (also known as sleep fragmentation) have received less experimental attention. Recently, there has been increasing interest in sleep restriction and disruption as it has been recognized that they have a similar impact on cognitive functioning as a period of total sleep deprivation. Sleep loss causes impairments in cognitive performance and simulated driving and induces sleepiness, fatigue and mood changes. This review examines recent research on the effects of sleep deprivation, restriction and disruption on cognition and neurophysiologic functioning in healthy adults, and contrasts the similarities and differences between these three modalities of sleep loss

The characteristics of sleep and sleep loss in adolescence : a review

Healthy, adequate sleep is integral to the process of growth and development during adolescence. At puberty, maturational changes in the underlying homeostatic and circadian sleep regulatory mechanisms influence the sleep-wake patterns of adolescents. These changes interact with psychosocial factors, such as increasing academic demands, hours spent in paid employment, electronic media use, and social opportunities, and constrict the time available for adolescents to sleep. Survey studies reveal that adolescents’ habitual sleep schedules are associated with cumulative sleep loss. As a consequence, there is growing concern about the effects of insufficient sleep on adolescents’ waking function. This review identifies and examines the characteristics of sleep and sleep loss in adolescents. It highlights the need for more research into the effects of chronic partial sleep deprivation in adolescents, and the process of extending sleep on weekends to recover the effects of sleep debt. An understanding of chronic sleep deprivation and recovery sleep in adolescents will facilitate the development of evidence-based sleep guidelines and recommendations for recovery sleep opportunities when habitual sleep times are insufficient

The characteristics of sleep and sleep loss in adolescence : a review

Healthy, adequate sleep is integral to the process of growth and development during adolescence. At puberty, maturational changes in the underlying homeostatic and circadian sleep regulatory mechanisms influence the sleep-wake patterns of adolescents. These changes interact with psychosocial factors, such as increasing academic demands, hours spent in paid employment, electronic media use, and social opportunities, and constrict the time available for adolescents to sleep. Survey studies reveal that adolescents’ habitual sleep schedules are associated with cumulative sleep loss. As a consequence, there is growing concern about the effects of insufficient sleep on adolescents’ waking function. This review identifies and examines the characteristics of sleep and sleep loss in adolescents. It highlights the need for more research into the effects of chronic partial sleep deprivation in adolescents, and the process of extending sleep on weekends to recover the effects of sleep debt. An understanding of chronic sleep deprivation and recovery sleep in adolescents will facilitate the development of evidence-based sleep guidelines and recommendations for recovery sleep opportunities when habitual sleep times are insufficient

Partial and sleep-stage-selective deprivation

Occupational, family, and social pressures have led to a society that sleeps less. In 1960, a survey by the American Cancer Society found that people slept, on average, 8 h per night. This figure has dropped today to 6.7 h, a decrease of 15% in less than one generation. This fall may be due to medical conditions, sleep disorders, or medications that inhibit sleep, as well as lifestyle disrupters such as jet lag, exam stress, or parenting infants. With the change toward a 24-h society, working outside of the 9-to-5 day has also become increasingly prevalent. Shift workers commonly obtain less sleep than permanent daytime workers as daytime sleep is sacrificed to accommodate social, family, and leisure activities. Sleep deprivation causes between $43 billion and$56 billion worth of accidents annually, as well as contributing to a substantial number of injuries and deaths worldwide. Humans are biologically programmed to sleep at night, and going without sleep has a range of deleterious consequences for cognitive performance, health, and well-being. This article will first outline the methodologies used to investigate partial sleep deprivation in humans and animals and discuss the neurobehavioral, physiological, and psychosocial consequences of reduced sleep. The article will then describe the function of sleep stages, again summarizing methodologies and reviewing the findings from rapid eye movement (REM) and slow-wave sleep (SWS) selective sleep stage deprivation studies in humans and animals

The factors influencing the eating behaviour of shiftworkers: What, when, where and why

Shiftwork leads to altered eating patterns, with workers often eating foods at all times across the 24 h period. Strategies to reduce the burden of shiftwork on the workers should be prioritised and altering these eating patterns is an important area for change. This narrative review examines the current evidence on the individual and environmental factors influencing the eating behaviours of shiftworkers. A systematic search was conducted and yielded 62 articles. These were split into four themes that influence eating patterns; When shiftworkers eat, What type of foods shiftworkers eat, Where the food is sourced from, and Why shiftworkers choose to eat on shift. Irregular working hours was the biggest influence on when workers ate on shift, shift-type was the biggest influence on what workers ate, the majority of food was sourced from canteens and cafeterias, and socialising with colleagues was the biggest reason why workers chose to eat. While more research is needed to explore multiple industries and shift-types, and to investigate the ideal size, type and timing of food on shift, this review has highlighted that future research into shiftworker eating needs to adopt an integrative approach and consider the different individual and social contexts that influence eating patterns

The influence of break timing on the sleep quantity and quality of fly-in, fly-out shiftworkers

Abstract: Although shift and break timing is known to affect the sleep of shiftworkers, this has not been demonstrated in Fly-in, Fly-out (FIFO) settings which, compared to residential based settings, may be favourable for sleep. This study investigated the sleep quantity and quality of shiftworkers working a FIFO operation comprising of shifts, and therefore breaks, across the 24-h day. The sleep of 24 males (50.43 ± 8.57 yr) was measured using actigraphy and sleep diaries. Morning breaks were associated with less sleep (09:00–12:00 h; 4.4 ± 1.3 h) and a poorer sleep quality (06:00–09:00 h; 3.1 ± 1.0, “average”) compared to breaks beginning between 00:00 h and 03:00 h (6.8 ± 1.7 h; 2.2 ± 0.9, “good”). Sleep efficiency remained constant regardless of break timing (85.9 ± 5.0% to 89.9 ± 3.5%). Results indicate that even in operations such as FIFO where sleeping conditions are near- optimal and the break duration is held constant, the influence of the endogenous circadian pace- maker on sleep duration is evident

Alcohol use in shiftworkers

It has been suggested that shiftworkers may consume alcohol to help them sleep, resulting in greater consumption. A large study in Australian workers suggested that those on non-standard schedules (outside 8 am–6 pm, Monday–Friday) do not drink more, but are at increased odds of binge drinking (heavy periods of drinking followed by abstinence) than workers on standard schedules. However, differences in types of non-standard schedules were not examined in the study. The current study examined the alcohol intake of Australian shiftworkers on fixed and rotating shifts. Shiftworkers (n = 118, age = 43.4 ± 9.9 y, 68% male) on 12 h-rotating (n = 29), 8 h-rotating (n = 29), morning (n = 33) and night (n = 27) schedules from printing, postal, nursing and oil industries participated. They completed a Cancer Council Dietary Questionnaire, recording frequency and amount of alcohol consumed on average per day over the preceding year. They also completed a shortened Standard Shiftwork Index, including questions on shift schedule, sleep duration, tiredness, gender and age. Average alcohol consumption was 9.6 ± 13.1 standard drinks/week. One in six reported using alcohol as a sleep aid between shifts at least sometimes and nearly one third reported consuming 12 or more drinks in 24 h. Alcohol consumption was higher for males and decreased with age. Controlling for gender and age, there were no significant differences between shift types in standard drinks/week (p = 0.50). However, those on 12-h rotating shifts consumed more drinks per 24 h (p = 0.04) and had less sleep (p < 0.001). Results support the suggestion that shiftworkers are likely to binge drink, particularly younger, male workers and those on long, rotating shifts. Alcohol use in shiftworkers may put increased pressure on already vulnerable physiological systems

Framework and metrics for online fatigue monitoring within submarine teams working in 24/7 environments

This paper addresses the question of online fatigue monitoring in high constrained work environments, by dealing more specifically with the activity of submariners. A state of the science is proposed on the concept of fatigue as well as physiological and behaviour metrics supporting the emergence of a fatigue management system for individuals and teams. From this, a framework for online fatigue monitoring in maritime environments is proposed

Interindividual and intraindividual variability in adolescent sleep patterns across an entire school term: A pilot study

Objectives: This study aimed to investigate sleep patterns in adolescent males over a 12-week period (a 10-week school term and pre and post term holidays). Design: Intensive longitudinal design, with sleep data collected daily via actigraphy for 81 consecutive days. Setting: Five Secondary Schools in Adelaide, South Australia. Participants: Convenience sample of 47 adolescent males aged 14 to 17 years. Measurements: Daily sleep duration, bedtimes, rise times, and sleep efficiency were collected via actigraphy with all (except sleep efficiency) also measured by sleep diary. Mood was measured weekly with Depression Anxiety Stress Scale-21 (DASS-21) and weekly wellbeing with the Satisfaction with Life Scale (SWLS). Age, body mass index, self-reported mood, life satisfaction, and chronotype preference assessed at baseline (pre-term holiday week) were included as covariates. Results: Dynamic Structural Equation Modeling indicated significant but small fixed-effect and random-effect auto-regressions for all sleep variables. Collectively, these findings demonstrate day-to-day fluctuations in sleep patterns, the magnitude of which varied between individuals. Age, morningness, and mood predicted some of the temporal dynamics in sleep over time but other factors (BMI, life satisfaction) were not associated with sleep dynamics. Conclusions: Using intensive longitudinal data, this study demonstrated inter-individual and intra-individual variation in sleep patterns over 81 consecutive days. These findings provide important and novel insights into the nature of adolescent sleep and require further examination in future studies

Establishment, persistence and the importance of longitudinal monitoring in multi-source reintroductions

Incorporating genetic data into conservation programmes improves management outcomes, but the impact of different sample grouping methods on genetic diversity analyses is poorly understood. To this end, the multi-source reintroduction of the eastern bettong Bettongia gaimardi was used as a long-term case study to investigate how sampling regimes may affect common genetic metrics and hence management decisions. The dataset comprised 5307 SNPs sequenced across 263 individuals. Samples included 45 founders from five genetically distinct Tasmanian source regions, and 218 of their descendants captured during annual monitoring at Mulligan’s Flat Woodland Sanctuary (121 samples across eight generations) and Tidbinbilla Nature Reserve (97 samples across nine generations). The most management-informative sampling regime was found to be generational cohorts, providing detailed long-term trends in genetic diversity. When these generation-specific trends were not investigated, recent changes in population genetics were masked, and it became apparent that management recommendations would be less appropriate. The results also illuminated the importance of considering establishment and persistence as separate phases of a multi-source reintroduction. The establishment phase (useful for informing early adaptive management) should consist of no less than two generations and continue until admixture is achieved (admixture defined here as >80% of individuals possessing >60% of source genotypes, with no one source composing >70% of >20% individuals’ genotype) is achieved. This ensures that the persistence phase analyses of population trends remain minimally biased. Based on this case study, we recommend that emphasis be given to the value of generationally specific analyses, and that conservation programmes collect DNA samples throughout the establishment and persistence phases and avoid collecting genetic samples only when the analysis is imminent. We also recommend that population genetic analyses for multi-source reintroductions consider whether admixture has been achieved when calculating descriptive genetic metrics