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Link to original content: http://pubmed.ncbi.nlm.nih.gov/23481485
Controlling light-dark exposure patterns rather than sleep schedules determines circadian phase - PubMed Skip to main page content
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. 2013 May;14(5):456-61.
doi: 10.1016/j.sleep.2012.12.011. Epub 2013 Mar 6.

Controlling light-dark exposure patterns rather than sleep schedules determines circadian phase

Kenneth Appleman  1 , Mariana G Figueiro, Mark S Rea
Affiliations

Controlling light-dark exposure patterns rather than sleep schedules determines circadian phase

Kenneth Appleman et al. Sleep Med. 2013 May.

Abstract

Objective: To examine, in a field study circadian phase changes associated with two different light-dark exposures patterns, one that was congruent with a phase advanced sleep schedule and one that was incongruent with an advanced schedule.

Methods: Twenty-one adults (mean age±standard deviation=22.5±3.9 years; 11 women) participated in the 12day study. After a five-day baseline period, participants were all given individualized, fixed, 90-minute advanced sleep schedules for one week. Participants were randomly assigned to one of two groups, an advance group with a light-dark exposure prescription designed to advance circadian phase or a delay group with light-dark exposure prescription designed to delay circadian phase. The advance group received two morning hours of short-wavelength (blue) light (λmax ≈ 476±1 nm, full-width-half-maximum ≈20 nm) exposure and three evening hours of light restriction (orange-filtered light, λ<525 nm=0). The delay group received blue light for three hours in the evening and light restriction for two hours in the morning. Participants led their normal lives while wearing a calibrated wrist-worn light exposure and activity monitor.

Results: After seven days on the 90-minute advanced sleep schedule, circadian phase advanced 132±19 minutes for the advance group and delayed 59±7.5 minutes for the delay group.

Conclusions: Controlling the light-dark exposure pattern shifts circadian phase in the expected direction irrespective of the fixed advanced sleep schedule.

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Conflict of interest statement

Conflict of Interest: The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2012.12.011.

Figures

Fig. 1
Fig. 1
CS light exposures, advance and delay groups. Absence of error bars for the intervention week data reflects the use of the blue-light goggles and the orange-tinted glasses.
Fig. 2
Fig. 2
Salivary DLMO Phase Shifts. Diamonds indicate phase shifts in salivary DLMO for participants in the advance (n = 10) and delay (n = 11) groups.
Fig. 3
Fig. 3
KSS Averages by time-of-day for the advance and delay groups. Asterisks identify significant differences between the baseline period and the intervention week for each group.
See this image and copyright information in PMC

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References

    1. Brainard GC, Hanifin JP, Greeson JM, Byrne B, Glickman G, Gerner E, et al. Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor. J Neurosci. 2001;21(16):6405–12. - PMC - PubMed
    1. Thapan K, Arendt J, Skene DJ. An action spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans. J Physiol. 2001;535(Pt 1):261–7. - PMC - PubMed
    1. Rea MS, Figueiro MG, Bullough JD, Bierman A. A model of phototransduction by the human circadian system. Brain Res Rev. 2005;50(2):213–28. - PubMed
    1. Wright HR, Lack LC. Effect of light wavelength on suppression and phase delay of the melatonin rhythm. Chronobiol Int. 2001;18(5):801–8. - PubMed
    1. Honma K, Honma S, Wada T. Phase-dependent shift of free-running human circadian rhythms in response to a single bright pulse. Experientia. 1987;43(11-12):1205–7. - PubMed

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