| 1. |
- de la Iglesia, Horacio O., et al.
(författare)
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Ancestral sleep
- 2016
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 26:7, s. R271-R272
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- While we do not yet understand all the functions of sleep, its critical role for normal physiology and behaviour is evident. Its amount and temporal pattern depend on species and condition. Humans sleep about a third of the day with the longest, consolidated episode during the night. The change in lifestyle from hunter-gatherers via agricultural communities to densely populated industrialized centres has certainly affected sleep, and a major concern in the medical community is the impact of insufficient sleep on health 1 and 2. One of the causal mechanisms leading to insufficient sleep is altered exposure to the natural light–dark cycle. This includes the wide availability of electric light, attenuated exposure to daylight within buildings, and evening use of light-emitting devices, all of which decrease the strength of natural light–dark signals that entrain circadian systems [3].
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| 2. |
- Lowden, Arne, 1957-, et al.
(författare)
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Delayed Sleep in Winter Related to Natural Daylight Exposure among Arctic Day Workers
- 2018
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Ingår i: Clocks & Sleep. - : MDPI AG. - 2624-5175. ; 1:1, s. 105-116
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Tidskriftsartikel (refereegranskat)abstract
- Natural daylight exposures in arctic regions vary substantially across seasons. Negative consequences have been observed in self-reports of sleep and daytime functions during the winter but have rarely been studied in detail. The focus of the present study set out to investigate sleep seasonality among indoor workers using objective and subjective measures. Sleep seasonality among daytime office workers (n = 32) in Kiruna (Sweden, 67.86° N, 20.23° E) was studied by comparing the same group of workers in a winter and summer week, including work and days off at the weekend, using actigraphs (motion loggers) and subjective ratings of alertness and mood. Actigraph analyses showed delayed sleep onset of 39 min in winter compared to the corresponding summer week (p < 0.0001) and shorter weekly sleep duration by 12 min (p = 0.0154). A delay of mid-sleep was present in winter at workdays (25 min, p < 0.0001) and more strongly delayed during days off (46 min, p < 0.0001). Sleepiness levels were higher in winter compared to summer (p < 0.05). Increased morning light exposure was associated with earlier mid-sleep (p < 0.001), while increased evening light exposure was associated with delay (p < 0.01). This study confirms earlier work that suggests that lack of natural daylight delays the sleep/wake cycle in a group of indoor workers, despite having access to electric lighting. Photic stimuli resulted in a general advanced sleep/wake rhythm during summer and increased alertness levels.
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| 3. |
- Moreno, Claudia R. C., et al.
(författare)
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Are We Ready to Implement Circadian Hygiene Interventions and Programs?
- 2022
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 19:24
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Tidskriftsartikel (refereegranskat)abstract
- Circadian hygiene, a concept not to be confused with the notion of public or social hygiene, should be discussed among experts and society. Light–dark cycles and other possible synchronizers of the human circadian timing system affect ways of life, including sleeping, eating, working and physical activity. Some of these behaviors have also been investigated individually as synchronizers (e.g., eating times). Therefore, the knowledge held today about circadian rhythms, and their implications for health, allows future perspectives in this field to be mapped. The present article summarizes the latest knowledge on factors influencing circadian rhythms to discuss a perspective for the future of health promotion based on circadian hygiene. However, it is important to highlight that circadian hygiene is the product of an imbrication of individual and societal involvement. First, it is important to adopt practices and devise public health policies in line with circadian hygiene. Second, individual healthy habits require internal rhythms to be examined. Last, the research agenda on circadian hygiene can be developed on a public as well as individual level, raising the question as to how much society is willing to embrace this change.
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| 4. |
- Teixeira, Liliane, et al.
(författare)
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Exposure to bright light during evening class hours increases alertness among working college students
- 2013
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Ingår i: Sleep Medicine. - : Elsevier BV. - 1389-9457 .- 1878-5506. ; 14:1, s. 91-97
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the effects of exposure to bright light on sleepiness during evening hours among college students. METHODS: Twenty-seven healthy college students, all males, with ages ranging from 21 to 24years, working during the day and studying in the evening, participated in this study. During the 3week study, the students wore actigraphs and recorded levels of sleepiness. In a crossover design, on the second and third weeks, the students were exposed to bright light (BL) at either 19:00 or 21:00h. Salivary melatonin samples were collected before and after BL exposure. ANOVA test for repeated measurements were performed. RESULTS: After BL exposure, sleepiness levels were reduced at 20:30 and 22:00h (F=2.2; p<0.05). ANOVA showed statistical differences between time (F=4.84; p=0.04) and between day and time of BL exposure (F=4.24; p=0.05). The results showed effects of melatonin onset at 20:00 and 21:30h and sleepiness levels (F=7.67; p=0.02) and perception of sleepiness and intervention time (F=6.52; p=0.01). CONCLUSION: Controlled exposure to BL during evening hours increased alertness among college students. The effects of BL on sleepiness varied according to the time of melatonin onset.
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