Publikováno:
2022, Clocks & Sleep, Basel, MDPI AG), p. 438-439)
Anotace:
Abstract: Background: In today’s modern society, people spend most of their time in buildings where they are usually exposed to a mere fraction of daylight. This, combined with artificial lighting in the evening, leads to a decrease in the contrast of the photic signal between day and night, which is essential for proper circadian entrainment. Insufficient exposure to bright daylight has been associated with disrupted synchronization of circadian rhythms and related consequences for health, quality of sleep, mood and overall well-being. This study aimed to explore whether winter morning exposure to electric lighting with unique, daylight-mimicking qualities provided by an experimental phototherapy booth prototype called Sun spa would have a significant effect on mood, sleep quality and circadian rhythmicity of healthy volunteers. Methods: The ‘Sun spa’ is a cubic interior pavilion with a side of 2.5 m. The ceiling and half of one side wall serve as the source of the light. It provides a corneal illuminance above 8000 lx, which represents Equivalent Daylight Illuminance >7400 lx, with a CCT of 4500 K and a color-rendering index above 90. The light has a diffuse character and balanced spatial distribution with maximal luminance of 8000 cd/m2, which is similar to the natural sky. In this preliminary study, 18 participants were exposed to 30 min experimental lighting inside of the ‘Sun spa’ from 10:00 am to 10:30 am for two consecutive workweeks during the winter months. Participants were monitored by MotionWatch8 actigraphy devices starting 2 weeks prior to the experimental lighting exposure and ending 2 weeks post-exposure. Self-report questionnaires and scales on sleep quality and mood were administered 2 days before the experimental lighting exposure and one day after the experimental lighting exposure. Results: During the two-week experimental lighting exposure, the Interdaily Stability of the participants´ circadian rhythmicity was significantly increased compared to the two weeks prior and two weeks post-exposure. Self-report scales and questionnaires on anxiety (STAI), depressive symptoms (BDI) and positive and negative affect (PANAS) revealed no significant differences pre- and postexposure. Conclusions: While the experimental lighting exposure significantly increased the interdaily stability of the participants´ circadian rhythmicity during the two weeks of exposure, the intervention had no significant effect on self-report ‘mood’ correlates. However, part of the experiment, affecting a subset of participants, took place when the war had already started and participants reported it affected their sleep quality and emotions. Moreover, it remains to be determined to what extent the increased interdaily stability actually reflected the required commitment to attend the ‘Sun spa’ regularly
Typ:
Abstrakt ve sborníku z prestižní konf.