Effects of Sleep Deprivation on Food Intake and Motor Activity in Man
HealthyEvidence that shortened period of sleep could be a risk factor for weight gain and obesity has grown over the past decade. Concurrent with the obesity epidemic, numerous studies have reported a parallel epidemic of chronic sleep deprivation. Sleep is important in maintaining energy balance (i.e. acute sleep deprivation impact the normal secretion of ghrelin and decreases leptin plasma levels). Surprisingly, in humans, there is no direct evidence that a shortened night has direct effect on energy metabolism during the following day. This study is set up to determine whether a partial sleep deprivation night has an impact on appetite and food energy intake and, concomitantly, on physical activity, during the following day.
Metabolomics-based Sleepiness Markers
Sleep DeprivationSleepiness1 moreEstimating that people sleep on average up to two hours less over the last decades, sleepiness and fatigue need to be considered as significant societal problems of the modern world. Jurisdiction is precise on how to deal with overtired offenders since they were not allowed to use machines or vehicles in the first place, similar to drunk individuals or consumers of illicit drugs. In contrast to alcohol or illicit drug use, however, there are no quick roadside or workplace tests as objective (analytical) biomarkers for sleepiness. Investigators hypothesize that increasing sleep drive or impaired wakefulness can be assessed by qualitative or quantitative fluctuations of certain metabolites in biological specimens, e.g., accumulation or decrease of endogenous substances related to sleep debt. Thus, this sleep study provides the necessary biological samples of either sleep-deprived, sleep-restricted, or control subjects, which are then analysed for appropriate metabolite biomarkers utilizing an untargeted metabolomics approach. In addition to established impairment tests, a state of the art driving simulator will be employed to objectively measure driving performance under all study conditions. Participants will also rate their subjective sleepiness using validated questionnaires.
Influence of Cognition and Physiological Function by Partial Sleep Deprivation
Sleep DeprivationPartial sleep deprivation (PSD), is a common problem among current university students in Taiwan. Students often get inadequate sleep time due to burden schoolwork during exam period. In recent years, Issue of sleep quality has gradually been emphasized. According to previous research, lacking in sleep easily results in sleepiness, fatigue, and poor problem-solving performance. Sleep deprivation may also affects cognitive performance, like reducing working memory performance. Furthermore, sleep deprivation will probably alter autonomic nervous function, such as sympathetic/parasympathetic activity change. Previous researches also suggested that sleep deprivation may associated with the risk of being obesity or suffering from diabetes. However, most researches focused on the effects of total sleep deprivation, especially those who usually have night shift work, such as medical staff. Few studies investigated the cognitive function and physiological function of university students after a period of time of partial sleep deprivation. As a results, the aim of the study is to investigate how partial sleep deprivation affects the cognitive performance and physiological function before and after the final exam period in healthy young university students between 20 and 30 years old in Taiwan, in order to promote the importance of healthy sleep and improve sleep quality among university students.
Evaluation of the Reliability and Validity of a Diagnostic Sleep Disorders Questionnaire
Sleep Apnea SyndromesInsomnia2 moreThe study aims to develop and test a user-friendly, accessible approach to sleep assessment which can function as an initial "triage" of targeted sleep conditions, such as insomnia, insufficient sleep syndrome, sleep apnea syndromes/snoring, and circadian sleep/wake disorders, within the clinical and community population. Specifically, this study will test the validity and reliability of a self-rated, digitized, and cost-effective diagnostic measure with sufficient sensitivity to accurately assess/diagnose common sleep conditions and/or risk for these conditions. Such an approach, would allow for faster assessment of common sleep conditions and disorders, and provide clinical knowledge to the individual, the physician, and if required insurance companies, as to those persons who need more immediate attention or treatment for their sleep condition.
Cortical Excitability and Decision Making After Total Sleep Deprivation and Sleep Restriction
Acute and Partial Sleep DeprivationThe investigators examine changes in decision making, vigilance and cortical excitability in healthy male subjects undergoing total acute sleep deprivation (40 hours) on the one hand, and chronic partial sleep restriction (7 nights with 5 instead of 8 hours in bed per night) on the other hand, in a cross over controlled manner. The investigators hypothesize that total sleep deprivation, as well as partial sleep restriction lead to impairments in decision making and vigilance, and enhanced cortical excitability. Beside these three primary outcomes, the investigators also assess changes in sleep by EEG, dim light melatonin onset, skin temperature, subjective mood and sleepiness, working memory, and also collect saliva samples.
The Evolution of Memories Across Wake and Sleep
Sleep DeprivationSleepTo further understanding of the relationship between sleep and memory the investigators will address and attempt to answer three questions, (1) how memories evolve across wake and sleep, (2) how different aspects of this memory evolution are reflected both behaviorally and in the EEG signal, and (3) what stages and features of sleep affect memory evolution. Together, these studies will provide a greater breadth and depth of knowledge concerning sleep's role in memory consolidation. Such knowledge would be of practical importance for educational practices, whether in schools, on the job, or in the military, and would also provide valuable information to the fields of sleep medicine and psychiatry, where interactions between sleep disorders and cognitive functioning are of great importance.
HIV-1, Insufficient Sleep and Vascular Endothelial Dysfunction
HIV-1The investigators hypothesize that chronic insufficient sleep is associated with diminished endothelium-dependent nitric oxide-mediated vasodilation and tissue-type plasminogen activator release in anti-retroviral (ART)-treated HIV-1-seropositive adults. Furthermore, the investigators hypothesize that the postulated diminishment in endothelial vasodilator and fibrinolytic function with insufficient sleep will be due, at least in part, to increased oxidative stress. Moreover, increasing sleep duration and improving sleep quality will increase both endothelium-dependent nitric oxide-mediated vasodilation and endothelial tissue-type plasminogen activator release in ART-treated HIV-1-seropositive adults. Increases in endothelial vasodilator and fibrinolytic function will be due, at least in part, to reduced oxidative stress.
Comparison Across Multiple Types of Sleep Deprivation
Sleep DeprivationSleep RestrictionThis study is designed to assess neurobehavioral performance, as well as genetic and other physiological changes associated with variations in timing and quantity of sleep.
Call- Associated Acute Fatigue in Surgical Residency
Sleep DeprivationThe study aimed to evaluate the effects of 24-Hour-Call-associated acute partial sleep deprivation on surgical residents' technical and cognitive performance in a virtual reality (VR) setting. Physiological parameters were used to quantify fatigue in respect to hours of sleep and subjective degrees of sleepiness. Technical performance and cognitive skills were assessed through low- and high fidelity tasks usig the VR- simulator LapSim. Objective alertness was measured by the standardized d2-Paper-Pencil-Test. Cited assessments were performed on three consecutive mornings- pre- and post-call as after 24 hours resting.
Cardiovascular Effects of Partial Sleep Deprivation
Sleep DeprivationBackground: Sleep curtailment is common and is associated with increased mortality due to cardiovascular causes. However, the mechanisms are not completely understood.We hypothesized that partial sleep deprivation caused however significant changes in sympathetic activity and endothelial function in healthy volunteers. Methods: Thirteen young healthy male volunteers will be monitored during 12 days by sleep diary and wrist actigraphy. The subjects will keep under their usual daily activities and randomized to 5 nights of prolonged sleep (control) or partial sleep deprivation, interposed by 2 nights of unrestricted sleep (wash out). At the end of each period, the subjects will be evaluate by: 1. electrocardiogram and beat-to-beat blood pressure with spectral analysis of heart rate and blood pressure in the supine position and after head up tilt test maneuver; 2. resting plasma norepinephrine; 3. venous endothelial function (dorsal hand vein technique).