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. 2017 Aug 8;7(1):7620.
doi: 10.1038/s41598-017-07060-8.

Differential impact in young and older individuals of blue-enriched white light on circadian physiology and alertness during sustained wakefulness

Virginie Gabel  1   2   3 , Carolin F Reichert  1   2 , Micheline Maire  1   2 , Christina Schmidt  4 , Luc J M Schlangen  5 , Vitaliy Kolodyazhniy  6 , Corrado Garbazza  1   2 , Christian Cajochen  7   8 , Antoine U Viola  1   2   9
Affiliations

Differential impact in young and older individuals of blue-enriched white light on circadian physiology and alertness during sustained wakefulness

Virginie Gabel et al. Sci Rep. .

Abstract

We tested the effect of different lights as a countermeasure against sleep-loss decrements in alertness, melatonin and cortisol profile, skin temperature and wrist motor activity in healthy young and older volunteers under extendend wakefulness. 26 young [mean (SE): 25.0 (0.6) y)] and 12 older participants [(mean (SE): 63.6 (1.3) y)] underwent 40-h of sustained wakefulness during 3 balanced crossover segments, once under dim light (DL: 8 lx), and once under either white light (WL: 250 lx, 2,800 K) or blue-enriched white light (BL: 250 lx, 9,000 K) exposure. Subjective sleepiness, melatonin and cortisol were assessed hourly. Skin temperature and wrist motor activity were continuously recorded. WL and BL induced an alerting response in both the older (p = 0.005) and the young participants (p = 0.021). The evening rise in melatonin was attentuated under both WL and BL only in the young. Cortisol levels were increased and activity levels decreased in the older compared to the young only under BL (p = 0.0003). Compared to the young, both proximal and distal skin temperatures were lower in older participants under all lighting conditions. Thus the color temperature of normal intensity lighting may have differential effects on circadian physiology in young and older individuals.

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Conflict of interest statement

Luc J.M. Schlangen is an employee of Philips Lighting Research, The Netherlands.

Figures

Figure 1
Figure 1
Time course of alertness, melatonin and cortisol profile and activity. Time course of the (a) Karolinska Sleepiness Scale (KSS), the (b) melatonin profile, the (c) cortisol profile and the (d) wrist activity in 26 young (left panel) and 12 older participants (right panel) under dim light (black lines), white light (red lines) or blue-enriched white light (blue lines). Data are plotted as a mean for each 2-hour bin for the KSS score, the melatonin and cortisol profile and in 3-hour bins for the wrist activity relative to elapsed time (hours) after wake-up. The error bars represent the standard error of the mean.
Figure 2
Figure 2
Time course of the change in melatonin concentration. Time course of the difference in melatonin concentration between the light conditions and DL (in 2 h bins). The horizontal black line represents the baseline under DL. The difference in melatonin concentration between BL and DL is depicted in light blue in the young (solid line) and in dark blue in the older (dashed line), and the difference between WL and DL is in red in the young (solid line) and in violet in the older (dashed line).
Figure 3
Figure 3
Time course of the distal-to-proximal skin temperature gradient (DPG), proximal and distal skin temperatures. Time course of the (a) distal-to-proximal skin temperature gradient (DPG), (b) proximal skin temperature and (c) distal skin temperature in 26 young participants (left panel) and 12 older (right panel) under dim light (black lines), white light (red lines) or blue enriched white light (blue lines). Data are plotted as a mean for each 3-hour bin relative to elapsed time (hours) after wake-up. The error bars represent the standard error of the mean.
Figure 4
Figure 4
Spectral composition. Spectral composition (light wavelength by irradiance; W/m2-nm) of the (a) polychromatic white light and the (b) blue-enriched polychromatic white light.
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References

    1. Cajochen C, Chellappa S, Schmidt C. What keeps us awake? The role of clocks and hourglasses, light, and melatonin. Int Rev Neurobiol. 2010;93:57–90. doi: 10.1016/S0074-7742(10)93003-1. - DOI - PubMed
    1. Czeisler CA, Gooley JJ. Sleep and circadian rhythms in humans. Cold Spring Harb Symp Quant Biol. 2007;72:579–597. doi: 10.1101/sqb.2007.72.064. - DOI - PubMed
    1. Chellappa, S. L., Gordijn, M. C. & Cajochen, C. Can light make us bright? Effects of light on cognition and sleep. Prog Brain Res190, 119–133, doi:B978-0-444-53817-8.00007-4[pii]0.1016/B978-0-444-53817-8.00007-4 (2011). - PubMed
    1. Gabel V, et al. Effects of artificial dawn and morning blue light on daytime cognitive performance, well-being, cortisol and melatonin levels. Chronobiol Int. 2013;30:988–997. doi: 10.3109/07420528.2013.793196. - DOI - PubMed
    1. Van De Werken M, et al. Effects of artificial dawn on sleep inertia, skin temperature, and the awakening cortisol response. J Sleep Res. 2010;19:425–435. doi: 10.1111/j.1365-2869.2010.00828.x. - DOI - PubMed

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