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Circadian RhythmEvidence & Dosage

The internal ~24h clock — light as the main signal, peripheral clocks in the organs.

Studies last updated

Evidence at a glance

Total studies
1,000
With abstract
49
Meta / Systematic / RCT
102
Highly cited
50
Publication years
1960–2027

Circadian Rhythm in the context of Sleep

This topic is part of our "Sleep" world. There you'll find methodology, evidence and the highest-impact levers — plus the order in which they sensibly build on each other.

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Top studies on Circadian Rhythm

Ranked by influential-citation count and publication year.

  1. Life between clocks: daily temporal patterns of human chronotypes.

    J Biol Rhythms2003n=500other200 influential citations

    Human behavior shows large interindividual variation in temporal organization. Extreme "larks" wake up when extreme "owls" fall asleep. These chronotypes are attributed to differences in the circadian clock, and in animals, the genetic…

  2. The two-process model of sleep regulation: a reappraisal.

    J Sleep Res2016Study200 influential citations

    In the last three decades the two-process model of sleep regulation has served as a major conceptual framework in sleep research. It has been applied widely in studies on fatigue and performance and to dissect individual differences in…

  3. Circadian regulation of glucose, lipid, and energy metabolism in humans.

    Metabolism2018review200 influential citations

    The circadian system orchestrates metabolism in daily 24-hour cycles. Such rhythms organize metabolism by temporally separating opposing metabolic processes and by anticipating recurring feeding-fasting cycles to increase metabolic…

  4. Association between light at night, melatonin secretion, sleep deprivation, and the internal clock: Health impacts and mechanisms of circadian disruption.

    Life Sci2017review200 influential citations

    Exposure to Artificial Light At Night (ALAN) results in a disruption of the circadian system, which is deleterious to health. In industrialized countries, 75% of the total workforce is estimated to have been involved in shift work and…

  5. Circadian rhythms and disorders of the timing of sleep.

    Lancet2022Review200 influential citations

    The daily alternation between sleep and wakefulness is one of the most dominant features of our lives and is a manifestation of the intrinsic 24 h rhythmicity underlying almost every aspect of our physiology. Circadian rhythms are…

  6. The effects of light therapy on sleep problems: A systematic review and meta-analysis.

    Sleep Med Rev2016n=115meta128 influential citations

    Although bright light therapy seems a promising treatment for sleep problems, research shows inconclusive results. This meta-analysis is the first to systematically review the effect of light therapy on sleep problems in general and on…

  7. Effects of artificial light at night on human health: A literature review of observational and experimental studies applied to exposure assessment.

    Chronobiol Int2015n=85review115 influential citations

    It has frequently been reported that exposure to artificial light at night (ALAN) may cause negative health effects, such as breast cancer, circadian phase disruption and sleep disorders. Here, we reviewed the literature assessing the…

  8. Circadian rhythms, sleep, and the menstrual cycle.

    Sleep Med2007review109 influential citations

    Women with ovulatory menstrual cycles have a circadian rhythm superimposed on the menstrual-associated rhythm; in turn, menstrual events affect the circadian rhythm. In this paper, we review circadian rhythms in temperature, selected…

  9. The influence of blue light on sleep, performance and wellbeing in young adults: A systematic review.

    Front Physiol2022systematic105 influential citations

    Introduction: Blue light from electronic devices has a bad reputation. It has a wavelength which may influence our circadian rhythm and cause bad sleep. But there are other aspects of blue light exposure which are often overlooked, for…

  10. Light exposure during sleep impairs cardiometabolic function.

    Proc Natl Acad Sci U S A2022Study102 influential citations

    SignificanceAmbient nighttime light exposure is implicated as a risk factor for adverse health outcomes, including cardiometabolic disease. However, the effects of nighttime light exposure during sleep on cardiometabolic outcomes and the…

Frequently asked

What dosage was studied?
• Questionnaire assessment of sleep times, self-reported light exposure, and chronotype on work and free days • Not applicable (Not reported) • Circadian system and circadian misalignment exposures discussed across experimental protocols
Which population does the evidence apply to?
Most studies investigated: unknown; animal.
Are there safety considerations for Circadian Rhythm?
• No adverse events reported. • None reported; this is a conceptual reappraisal rather than an interventional study. • Not reported • ALAN exposure is described as deleterious to health.

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