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Author Mottram, V.; Middleton, B.; Williams, P.; Arendt, J.
Title (up) The impact of bright artificial white and 'blue-enriched' light on sleep and circadian phase during the polar winter Type Journal Article
Year 2011 Publication Journal of Sleep Research Abbreviated Journal J Sleep Res
Volume 20 Issue 1 Pt 2 Pages 154-161
Keywords Adult; Circadian Rhythm/*physiology; *Cold Climate; Female; Humans; *Light; Male; Medical Records; Questionnaires; Sleep/*physiology; Time Factors; blue light
Abstract Delayed sleep phase (and sometimes free-run) is common in the Antarctic winter (no natural sunlight) and optimizing the artificial light conditions is desirable. This project evaluated sleep when using 17,000 K blue-enriched lamps compared with standard white lamps (5000 K) for personal and communal illumination. Base personnel, 10 males, five females, 32.5+/-8 years took part in the study. From 24 March to 21 September 2006 light exposure alternated between 4-5-week periods of standard white (5000 K) and blue-enriched lamps (17,000 K), with a 3-week control before and after extra light. Sleep and light exposure were assessed by actigraphy and sleep diaries. General health (RAND 36-item questionnaire) and circadian phase (urinary 6-sulphatoxymelatonin rhythm) were evaluated at the end of each light condition. Direct comparison (rmanova) of blue-enriched light with white light showed that sleep onset was earlier by 19 min (P=0.022), and sleep latency tended to be shorter by 4 min (P=0.065) with blue-enriched light. Analysing all light conditions, control, blue and white, again provided evidence for greater efficiency of blue-enriched light compared with white (P<0.05), but with the best sleep timing, duration, efficiency and quality in control natural light conditions. Circadian phase was earlier on average in midwinter blue compared with midwinter white light by 45 min (P<0.05). Light condition had no influence on general health. We conclude that the use of blue-enriched light had some beneficial effects, notably earlier sleep, compared with standard white light during the polar winter.
Address British Antarctic Survey Medical Unit, Derriford Hospital, Plymouth, UK
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0962-1105 ISBN Medium
Area Expedition Conference
Notes PMID:20723022 Approved no
Call Number IDA @ john @ Serial 348
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Author Lack, L.C.; Gradisar, M.; Van Someren, E.J.W.; Wright, H.R.; Lushington, K.
Title (up) The relationship between insomnia and body temperatures Type Journal Article
Year 2008 Publication Sleep Medicine Reviews Abbreviated Journal Sleep Med Rev
Volume 12 Issue 4 Pages 307-317
Keywords Human Health; Arousal/physiology; Body Temperature Regulation/*physiology; Circadian Rhythm/physiology; Homeostasis/physiology; Humans; Melatonin/blood; Phototherapy; Skin Temperature/physiology; Sleep Disorders, Circadian Rhythm/physiopathology/therapy; Sleep Initiation and Maintenance Disorders/*physiopathology/therapy; Sympathetic Nervous System/physiopathology; Wakefulness/physiology
Abstract Sleepiness and sleep propensity are strongly influenced by our circadian clock as indicated by many circadian rhythms, most commonly by that of core body temperature. Sleep is most conducive in the temperature minimum phase, but is inhibited in a “wake maintenance zone” before the minimum phase, and is disrupted in a zone following that phase. Different types of insomnia symptoms have been associated with abnormalities of the body temperature rhythm. Sleep onset insomnia is associated with a delayed temperature rhythm presumably, at least partly, because sleep is attempted during a delayed evening wake maintenance zone. Morning bright light has been used to phase advance circadian rhythms and successfully treat sleep onset insomnia. Conversely, early morning awakening insomnia has been associated with a phase advanced temperature rhythm and has been successfully treated with the phase delaying effects of evening bright light. Sleep maintenance insomnia has been associated not with a circadian rhythm timing abnormality, but with nocturnally elevated core body temperature. Combination of sleep onset and maintenance insomnia has been associated with a 24-h elevation of core body temperature supporting the chronic hyper-arousal model of insomnia. The possibility that these last two types of insomnia may be related to impaired thermoregulation, particularly a reduced ability to dissipate body heat from distal skin areas, has not been consistently supported in laboratory studies. Further studies of thermoregulation are needed in the typical home environment in which the insomnia is most evident.
Address School of Psychology, Flinders University, South Australia, Australia. leon.lack@flinders.edu.au
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1087-0792 ISBN Medium
Area Expedition Conference
Notes PMID:18603220 Approved no
Call Number LoNNe @ kagoburian @ Serial 775
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Author Joo, E.Y.; Abbott, S.M.; Reid, K.J.; Wu, D.; Kang, J.; Wilson, J.; Zee, P.C.
Title (up) Timing of light exposure and activity in adults with delayed sleep-wake phase disorder Type Journal Article
Year 2016 Publication Sleep Medicine Abbreviated Journal Sleep Med
Volume 32 Issue Pages 259-265
Keywords Human Health
Abstract OBJECTIVE: To characterize the patterns of light exposure and physical activity level and assess their relationship with sleep quality and depressive symptoms in adults with delayed sleep-wake phase disorder (DSWPD). METHODS: 42 DSWPD (22 female, mean age 34.5 y) and 26 (+/-4 years) age-and-sex-matched controls (12 female, mean age 33.4 y) underwent seven days of light and activity monitoring. RESULTS: Individuals with DSWPD had significantly delayed bed times and wake times, but similar sleep duration compared to controls. Subjective sleep quality (Pittsburgh Sleep Quality Index (PSQI)) was poorer in DSWPDs compared to controls. Those with DSWPD had significantly more activity and light exposure late at night (2:00-4:00) and significantly less activity and light exposure in the morning (8:00-11:00). Total 24 h levels of light and activity were not significantly different between DSWPD and controls. However, the DSWPD group had significantly more light exposure than controls 22 h after waking, during their sleep period. Later light exposure correlated with higher depression scores [Beck Depression Index (BDI)] and poorer sleep quality (PSQI). CONCLUSIONS: The light exposure patterns observed in DSWPD likely contribute to and perpetuate the chronically delayed sleep and wake phase in these patients. In addition, increased light exposure during the sleep period may also contribute to the poor sleep quality and mood disorders that are common in these individuals.
Address Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA. Electronic address: p-zee@northwestern.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1389-9457 ISBN Medium
Area Expedition Conference
Notes PMID:27964860 Approved no
Call Number LoNNe @ kyba @ Serial 1639
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