Sleep Deprivation Reduces Tear Secretion and Impairs the Tear Film
We Investigated the Effect of Sleep Deprivation on the Tear Film and Ocular Surface.Tear film consists of three layers including outer lipid layer, aqueous layer and inner mucin layer.1,2 Lipid layer protects the aqueous layer of tear film from evaporation and mucin layer adhere the tear film to ocular surface. Aqueous layer, which is produced in lacrimal glands, is the most important in the health of ocular surface. Reduction of aqueous tear secretion results in the disruption of homeostasis at ocular surface and leads to dry eye syndrome.2 Dry eye syndrome is a common ocular surface disease associated with symptoms of eye discomfort, grittness and visual disturbance.1,2 Dry eye syndrome disrupts normal homeostasis at the ocular surface resulting in epithelial damage, epithelial cell apoptosis, loss of goblet cells, and squamous metaplasia.1-3 The changes and inflammation of ocular surface subsequently lead to tear instability, which causes an increased tear osmolarity and aggravates the inflammatory cascades. This leads to a vicious cycle.2 The regulation of tear film secretion is under neural and hormonal control.4 Dry eye syndrome has been associated with diverse and multiple causes, including depressive disorder, drugs, hormonal status, and systemic diseases.2 Sleep deprivation (SD) is known to cause profound impair¬ments in executive function and vigilant attention.5,6 It is also reportedly associated with autonomic and endocrine functioning7-9 and has been shown to increase blood pressure and stress hormone levels and decrease parasympathetic tone.10,11 Tear secretion is regulated by neurological factors and hormones,12 and so SD may have an effect on the tear film and ocular surface. However, only a few studies have evaluated the effect of sleep on the tear film and ocular surface. In this study, we investigated the effect of SD on the tear film and ocular surface.
Mechanisms of Sleep Disruption Hyperalgesia
Sleep DeprivationPainTwenty percent of Americans suffer from chronic pain. Sleep disturbance is similarly prevalent and among the most common and disabling neurobehavioral problems associated with chronic pain. This research is designed to evaluate the effects of disrupted sleep patterns on mood, inflammation, the perception of pain, and pain relief. This study will help researchers understand the relationship between sleep and pain, and how sleep disturbance might influence chronic pain conditions.
Repeated Challenge of Insufficient Sleep: Endothelial Effects
Repeated Short Sleep ScheduleThe 24-hour-a-day, 7-day a week, work-world arrived within our lifetimes, and is here to stay. Americans are working more and more, frequently at multiple jobs. The pattern of short sleep during the week followed by attempts to recover on the weekend is in common practice, but we know little of the associated health risks. What is the cost in terms of increasing known risk markers for cardiovascular disease, of repeated nights of insufficient sleep, and is this cost compounded with repetition, without adequate recovery? Evidence is accumulating to suggest that short sleep duration is linked to the development of metabolic and inflammation-associated diseases, such as cardiovascular disease. Mechanisms involved in the development of cardiovascular disease include impaired vascular function and inflammation. The current proposal is designed to investigate the effects of repeated periods of short nocturnal sleep duration in 4 cycles (each cycle consisting of 3 nights of 4 hours of sleep opportunity per night), and each cycle of short sleep followed by a single night of recovery sleep. Vascular reactivity will be assessed using brachial artery flow mediated dilation, and microcirculatory vasodilation will be assessed using perfusion imaging techniques. The dependence of IL-6 and sVCAM-1 as measured in peripheral circulation, on vascular function, will also be investigated.
Phenotypic and Genotypic Markers of Performance Vulnerability to Sleep Loss
Sleep Restriction Then Total Sleep DeprivationTotal Sleep Deprivation Then Sleep RestrictionInsufficient sleep is common, affecting 20-40% of adults, and resulting from sleep disorders, medical conditions, work demands, stress/emotional distress, and social/domestic responsibilities. It produces significant social, financial and health-related costs, and it has increasingly become a major public health concern as population studies worldwide have found that reduced sleep duration is associated with increased risks of obesity, morbidity, and mortality. It is well established that sleep loss causes fatigue and sleepiness, as well as errors and accidents that are due to its adverse neurobehavioral effects on alertness, mood, and cognitive functions. However, there are substantial, trait-like differences among people in the extent to which they experience such neurobehavioral deficits when sleep deprived. Common genetic variations involved in sleep-wake, circadian, and cognitive regulation may underlie these large inter-individual differences in neurobehavioral vulnerability to sleep deprivation, though it remains unclear whether different types of sleep deprivation involve the same phenotypic responses and same genotypic contributors. This project will be the first large-scale investigation of markers of differential cognitive vulnerability to both acute total sleep loss and chronic partial sleep loss. It will identify individuals who are at significant risk for fatigue and severe impairments from sleep loss. A total of 110 healthy adults will undergo a 13-day laboratory protocol to thoroughly characterize their cognitive, psychological and physiological responses to two of the most common forms of sleep loss--acute total sleep deprivation (1 night of sleep loss) and chronic partial sleep deprivation (5 nights of sleep limited to 4 hr). The findings from this study will represent a critical first step toward tailoring appropriate follow-up interventions for sleep loss and its symptomatic relief by finding predictors of at-risk individuals who should avoid sleep loss whenever possible, and/or seek effective countermeasures. Whether or not markers of neurobehavioral vulnerability to sleep loss are identified, the results of the project will help inform public policies pertaining to the need for adequate sleep and for countermeasures for sleep loss, and also will further our understanding and management of vulnerability to excessive sleepiness due to common sleep and medical disorders.
Impact of a Sleep Debt in Middle-Aged and Older Adults
Sleep RestrictionThis project has 6 aims. To examine the impact of recurrent partial sleep loss in young, middle-aged and older men and women. Sleep will be restricted to 4 hours. To test the hypothesis that extending bedtimes to allow for sleep recovery will reverse the metabolic, endocrine, and cardiovascular and neuro-behavioral alterations resulting from sleep restriction. Sleep will be extended to 12 hours following the 4 hour sleep restriction. To test the hypothesis that there are age and gender differences in the total amount of sleep recovery obtained during the week of 12-hour bedtimes. To test the hypothesis that there are age and gender differences in sleep capacity (the amount of time an individual can sleep per night when there is no sleep debt). To test the hypothesis that sleep capacity is partly determined by baseline levels of slow-wave sleep and slow-wave activity. To determine whether sleep capacity is related to sleep need by examining metabolic, endocrine, cardiovascular and neuro-behavioral changes with the amount of the individual sleep debt.
Sleep Loss and Energy Metabolism in People With Family History of Type 2 Diabetes.
SleepSleep Deprivation2 moreThe use of energy from food changes when people sleep. However, it is still not known if differences in the amount of nighttime sleep have an effect on the amount of energy that people who have a relative with type 2 diabetes (parent, sibling, or grandparent) use to perform their daily activities. This study is being done to test the hypothesis that the daily use of energy in people who have a history of type 2 diabetes in their family will be different after they have slept short hours for 16 days in comparison to when they have slept longer hours for 16 days.
Effects of Donepezil and Memantine on Cognitive Functions After a Sleep Deprivation Challenge in...
HealthyThe aim of this study is to assess the utility of sleep deprivation as a potential model for prediction of clinical efficacy using a combination of cognitive physiological endpoints.
Biomarkers of Insufficient Sleep and Sleepiness
Sleep DeprivationInsufficient Sleep Syndrome1 moreSleep and wakefulness disorders impact 50 to 70 million Americans and insufficient sleep is epidemic with over 50% of Americans reporting less than 7 hours of sleep per night. Health problems associated with insufficient sleep include inflammation, depression and anxiety, diabetes, stress, drug abuse, poor quality of life, obesity, and fatigue related accidents on the job/while driving. While the contribution of sleep to overall health, well-being, and public safety is recognized, no established clinical biomarkers of sleep deficiency exist. Such biomarkers would have utility as road-side biomarkers of sleepiness (e.g., drowsy driving), monitoring on the job fatigue/fitness for duty (e.g., transportation, military ops health care), monitoring sleep health, as well as for clinical diagnostics and measures of clinical treatment outcomes. Thus, investigators designed a controlled laboratory insufficient sleep protocol utilizing metabolomics to identify biomarkers of insufficient sleep. Investigators propose to identify changes in metabolites that consistently occur during insufficient sleep. As an exploratory outcome investigators will examine associated changes in metabolites and cognitive performance during insufficient sleep.
Light Intervention for Adaptation to Night Work
Shift-Work Related Sleep DisturbanceSleep Deprivation1 moreThe project will contribute with new knowledge concerning how aspects of the physical work environment (lighting conditions) can be arranged to facilitate the workers' adaptation to night work. This is important given the reported adverse consequences of shift work for performance, safety, and health. The project involves a series of three experimental, laboratory based shift work simulation studies. The aim is to investigate how different lighting conditions (intensities and colour temperature), administered through light emitting diode (LED) based bright light integrated standard room lighting, affects adaptation to three consecutive simulated night shifts and re adaptation to a day oriented schedule on measures of alertness, cognitive performance, sleep and circadian rhythm. The proposed project examines the effects of interventions that can be applied in naturalistic settings and will be based on new laboratory infrastructure available at the laboratories situated in the Faculty of Psychology, University of Bergen.
Real-Time Caffeine Optimization During Total Sleep Deprivation
CaffeineSleep Deprivation1 moreSleep deprivation (SD) has a powerful degrading effect on cognitive performance, particularly psychomotor vigilance (PV) and reaction time. Caffeine is well known to be an effective countermeasure to the effects of SD. However, individuals differ in both their response to SD and to the administration of caffeine. This has made it difficult to provide individualized recommendations regarding the use of caffeine to sustain alertness when needed. For the past two decades, the Army's Biotechnology HPC Institute (BHSAI), in collaboration with the Walter Reed Army Institute of Research, have been developing statistical models to predict individual performance during prolonged SD. Recently, this resulted in the publication of the 2B-Alert app, a computer algorithm based on large datasets that can learn an individual's response to SD by combining actigraphic sleep data with simultaneously acquired PV performance data. The 2B-Alert algorithm can predict an individual's sleep need and performance after ~2 weeks of training the model. Recently, the model has been extended to incorporate individualized responses to caffeine. This was recently validated in a retrospective study published by BHSAI in 2019. The present study is designed to test the predictive capacity of the 2B-Alert app in real time. During Phase 1 a total of 21 healthy participants will wear an actigraph & complete multiple daily PV tests on a personal cell phone. After 2 weeks, these individuals will attend Phase 2 involving an in-laboratory stay & SD. Participants will have an 8-hour period of sleep in the laboratory, followed by 62 hours of continuous wakefulness. During these 62 hours, participants will complete PV and mood testing every 3 hours. The 2B-Alert app will be used to predict individual caffeine need to sustain performance at near-baseline levels based on the statistical model. At 44 hours SD, participants will undergo a 6-hour "alertness window" where they may receive individualized doses of caffeine based on the recommendations of the model. After 62 hours of SD, Phase 3 begins, involving a night of monitored recovery sleep and additional sessions of PV and mood testing until release from the study at 6 pm on the final day. It is hypothesized that the 2B-Alert app will be effective at providing caffeine dosing recommendations that return PV and mood performance to normal levels during the alertness window.