Perspective: Casting light on sleep deficiency

Division of Sleep Medicine, Harvard Medical School, and Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, in Boston, Massachusetts.
Nature (Impact Factor: 41.46). 05/2013; 497(7450):S13. DOI: 10.1038/497S13a
Source: PubMed


The use of electric lights at night is disrupting the sleep of more and
more people, says Charles Czeisler.

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    • "As more time is spent under electrical light exposure in work places, daily exposure to darkness and total sleep durations have decreased [1]. As a result, the production of hormones such as melatonin is disturbed [2]. The impact of this metabolic alteration depends on the age, sex, and activity schedule (work, school, social interaction) of each individual. "
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    ABSTRACT: Objective This epidemiological study evaluated the impact of school time on sleep parameters of children and adolescents. Methods 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. Results 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 R2 = 0.95; F = 1606.87; p < 0.001). Conclusion The results showed that school time influences the sleep parameters. The association of school schedules and physiological factors influence the sleep/wake cycle.
    No preview · Article · Jan 2016 · Sleep Medicine
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    • "ight affects our circadian rhythms more powerfully than any drug " Czeisler, 2013, S13. prof. "
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    DESCRIPTION: The ties between our social context, our spatial, physical and technological environment and human experience are many and this web of relationships does not easily lend itself to a comprehensive discussion, nor to all-inclusive investigation. In this inaugural lecture I make a case for a contextual perspective in human-technology interaction by illustrating how the investigation and innovation of technical products and services requires a thorough understanding of the contextualized nature of human experience. Light is one of those crucial, but generally ignored aspects of context with varied and profound effects on affect, cognition, behavior, and health. But at the same time, light’s effects cannot be understood outside of their physical, social and temporal context. Light research, therefore, nicely illustrates why we need a combination of fundamental, translational and applied research efforts, and close collaboration with experts in myriad other domains to make meaningful progress. Inaugural lecture 13 November 2015
    Full-text · Research · Nov 2015
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    • "By this route, information about the amount of light falling on the retina regulates the operation of the SCN, controlling circadian rhythms, including sleep and waking. " [L]ight affects our circadian rhythms more powerfully than any drug " (Czeisler, 2013, S13). The regularly repeating daily exposure to light and dark results in a stable sleepewake cycle, which is essential for mental and physical health (e.g., Alvarez & Ayas, 2004; Alvaro, Roberts, & Harris, 2013). "

    Full-text · Article · Jan 2014 · Journal of Environmental Psychology
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