Are Individual Differences in Sleep and Circadian Timing Amplified by Use of Artificial Light Sources?

Journal of Biological Rhythms - Tập 32 Số 2 - Trang 165-176 - 2017
Krithika Swaminathan1, Elizabeth B. Klerman1, Andrew J. K. Phillips1,2
1Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
2School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia

Tóm tắt

Within the human population, there is large interindividual variability in the timing of sleep and circadian rhythms. This variability has been attributed to individual differences in sleep physiology, circadian physiology, and/or light exposure. Recent experimental evidence suggests that the latter is necessary to evoke large interindividual differences in sleep and circadian timing. We used a validated model of human sleep and circadian physiology to test the hypothesis that intrinsic differences in sleep and circadian timing are amplified by self-selected use of artificial light sources. We tested the model under 2 conditions motivated by an experimental study (Wright et al., 2013): (1) a “natural” light cycle, and (2) a “realistic” light cycle that included attenuation of light due to living indoors when natural light levels are high and use of electric light when natural light levels are low. Within these conditions, we determined the relationship between intrinsic circadian period (within the range of 23.7-24.6 h) and timing of sleep onset, sleep offset, and circadian rhythms. In addition, we simulated a work week, with fixed wake time for 5 days and free sleep times on weekends. Under both conditions, a longer intrinsic period resulted in later sleep and circadian timing. Compared to the natural condition, the realistic condition evoked more than double the variation in sleep timing across the physiological range of intrinsic circadian periods. Model predictions closely matched data from the experimental study. We found that if the intrinsic circadian period was long (>24.2 h) under the realistic condition, there was significant mismatch in sleep timing between weekdays and weekends, which is known as social jetlag. These findings indicate that individual tendencies to have very delayed schedules can be greatly amplified by self-selected modifications to the natural light/dark cycle. This has important implications for therapeutic treatment of advanced or delayed sleep phase disorders.

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Tài liệu tham khảo

10.1081/CBI-100103190

10.1016/j.jadohealth.2013.09.004

10.1038/oby.2011.100

10.1177/074873099129000777

10.1007/978-1-4615-1201-1_2

Daan S, 1984, Am J Physiol, 246, R161

10.1177/0748730410397645

10.1073/pnas.1010666108

10.1016/j.jsmc.2009.01.004

10.1037/0735-7044.115.4.895

10.1177/074873099129000867

10.1371/journal.pone.0091982

10.1177/0748730413504277

10.1073/pnas.0702835104

10.1016/j.pscychresns.2013.08.005

10.1093/sleep/28.11.1446

10.1177/074873049901400608

10.1177/0748730412475042

Klerman EB, 1996, Am J Physiol, 270, R271

10.1177/074873099129001073

10.1371/journal.pone.0042059

10.1111/sbr.12077

10.1016/j.tins.2013.10.004

10.3109/07420528.2012.741171

10.1177/0748730405277982

10.1177/0748730410369208

10.1177/0748730411414163

10.1371/journal.pcbi.1003213

10.1177/0748730406297512

10.1016/j.jtbi.2008.08.022

10.1007/BF01417856

10.1007/s00359-014-0927-x

10.1007/s00285-009-0276-5

10.1103/PhysRevE.56.826

10.1016/j.cub.2012.03.038

10.1007/978-3-642-25950-0_13

10.1016/j.smrv.2007.07.005

10.1177/074873099129001019

10.1101/sqb.2007.72.043

10.1177/0748730414550199

10.1371/journal.pone.0000721

10.1126/sciadv.1501705

10.1007/978-3-662-22492-2

10.1080/07420520500545979

10.1016/j.cub.2013.06.039

10.1016/j.cub.2015.09.046