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Author Joo, E.Y.; Abbott, S.M.; Reid, K.J.; Wu, D.; Kang, J.; Wilson, J.; Zee, P.C.
Title 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 (down) 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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Author Akacem, L.D.; Wright, K.P.J.; LeBourgeois, M.K.
Title Bedtime and evening light exposure influence circadian timing in preschool-age children: A field study Type Journal Article
Year 2016 Publication Neurobiology of Sleep and Circadian Rhythms Abbreviated Journal Neurobiol Sleep Circadian Rhythms
Volume 1 Issue 2 Pages 27-31
Keywords Human Health
Abstract Light exposure and sleep timing are two factors that influence inter-individual variability in the timing of the human circadian clock. The aim of this study was to quantify the degree to which evening light exposure predicts variance in circadian timing over and above bedtime alone in preschool children. Participants were 21 children ages 4.5-5.0 years (4.7 +/- 0.2 years; 9 females). Children followed their typical sleep schedules for 4 days during which time they wore a wrist actigraph to assess sleep timing and a pendant light meter to measure minute-by-minute illuminance levels in lux. On the 5th day, children participated in an in-home dim-light melatonin onset (DLMO) assessment. Light exposure in the 2 h before bedtime was averaged and aggregated across the 4 nights preceding the DLMO assessment. Mean DLMO and bedtime were 19:22 +/- 01:04 and 20:07 +/- 00:46, respectively. Average evening light exposure was 710.1 +/- 1418.2 lux. Children with later bedtimes (lights-off time) had more delayed melatonin onset times (r=0.61, p=0.002). Evening light exposure was not independently associated with DLMO (r=0.32, p=0.08); however, a partial correlation between evening light exposure and DLMO when controlling for bedtime yielded a positive correlation (r=0.46, p=0.02). Bedtime explained 37.3% of the variance in the timing of DLMO, and evening light exposure accounted for an additional 13.3% of the variance. These findings represent an important step in understanding factors that influence circadian phase in preschool-age children and have implications for understanding a modifiable pathway that may underlie late sleep timing and the development of evening settling problems in early childhood.
Address Sleep and Development Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
Corporate Author Thesis
Publisher (down) Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2451-9944 ISBN Medium
Area Expedition Conference
Notes PMID:28042611; PMCID:PMC5193478 Approved no
Call Number LoNNe @ kyba @ Serial 1755
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Author Wams, E.J.; Woelders, T.; Marring, I.; van Rosmalen, L.; Beersma, D.G.M.; Gordijn, M.C.M.; Hut, R.A.
Title Linking Light Exposure and Subsequent Sleep: A Field Polysomnography Study in Humans Type Journal Article
Year 2017 Publication Sleep Abbreviated Journal Sleep
Volume 40 Issue 12 Pages
Keywords actigraphy; chronobiology; circadian rhythms; scoring; sleep/wake mechanisms
Abstract Study objectives: To determine the effect of light exposure on subsequent sleep characteristics under ambulatory field conditions. Methods: Twenty healthy participants were fitted with ambulatory polysomnography (PSG) and wrist-actigraphs to assess light exposure, rest-activity, sleep quality, timing, and architecture. Laboratory salivary dim-light melatonin onset was analyzed to determine endogenous circadian phase. Results: Later circadian clock phase was associated with lower intensity (R2 = 0.34, chi2(1) = 7.19, p < .01), later light exposure (quadratic, controlling for daylength, R2 = 0.47, chi2(3) = 32.38, p < .0001), and to later sleep timing (R2 = 0.71, chi2(1) = 20.39, p < .0001). Those with later first exposure to more than 10 lux of light had more awakenings during subsequent sleep (controlled for daylength, R2 = 0.36, chi2(2) = 8.66, p < .05). Those with later light exposure subsequently had a shorter latency to first rapid eye movement (REM) sleep episode (R2 = 0.21, chi2(1) = 5.77, p < .05). Those with less light exposure subsequently had a higher percentage of REM sleep (R2 = 0.43, chi2(2) = 13.90, p < .001) in a clock phase modulated manner. Slow-wave sleep accumulation was observed to be larger after preceding exposure to high maximal intensity and early first light exposure (p < .05). Conclusions: The quality and architecture of sleep is associated with preceding light exposure. We propose that light exposure timing and intensity do not only modulate circadian-driven aspects of sleep but also homeostatic sleep pressure. These novel ambulatory PSG findings are the first to highlight the direct relationship between light and subsequent sleep, combining knowledge of homeostatic and circadian regulation of sleep by light. Upon confirmation by interventional studies, this hypothesis could change current understanding of sleep regulation and its relationship to prior light exposure. Clinical trial details: This study was not a clinical trial. The study was ethically approved and nationally registered (NL48468.042.14).
Address Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands
Corporate Author Thesis
Publisher (down) Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0161-8105 ISBN Medium
Area Expedition Conference
Notes PMID:29040758; PMCID:PMC5806586 Approved no
Call Number GFZ @ kyba @ Serial 1885
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Author Wilson IV, J.; Reid, K.J.; Braun, R.I.; Abbott, S.M.; Zee, P.C.
Title Habitual Light Exposure Relative to Circadian Timing in Delayed Sleep-Wake Phase Disorder Type Journal Article
Year 2018 Publication Sleep Abbreviated Journal
Volume in press Issue Pages
Keywords Human Health
Abstract Study Objectives

To compare melatonin timing, a well validated marker for endogenous circadian phase, and habitual light exposure patterns in adults with delayed sleep-wake phase disorder (DSWPD) and intermediate chronotype controls.

Methods

12 individuals with DSWPD (5 females, mean age 31.1) and 12 age matched controls (6 females, mean age 33.6) underwent a minimum of seven days of light and activity monitoring followed by an inpatient hospital stay, where blood was taken to assess melatonin timing (calculated as dim light melatonin onset – DLMO). Habitual light exposure patterns were then compared to a human phase response curve (PRC) to light.

Results

Relative to clock time, individuals with DSWPD had a later light exposure pattern compared to controls, but their light exposure pattern was earlier relative to DLMO. According to the human phase response curve (PRC) to light, individuals with DSWPD had less daily advancing light exposure compared to controls. The primary difference was seen in the late portion of the advancing window, in which individuals with DSWPD were exposed to fewer pulses of light of equivalent duration and intensity compared to controls.

Conclusions

Diminished advancing light exposure may play a role in the development and perpetuation of delayed sleep-wake timing in individuals with DSWPD. Enhancing light exposure during the later portion of the advancing window represents an innovative and complementary strategy that has the potential to improve the effectiveness of bright light therapy in DSWPD.
Address
Corporate Author Thesis
Publisher (down) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0161-8105 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1990
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Author Yates, J.
Title Perspective: The Long-Term Effects of Light Exposure on Establishment of Newborn Circadian Rhythm Type Journal Article
Year 2018 Publication Journal of Clinical Sleep Medicine Abbreviated Journal Jcsm
Volume 14 Issue 10 Pages 1829-1830
Keywords Commentary; Human Health
Abstract Development of newborns continues postnatally. Evidence has accumulated on the early life programming effects of light exposure on the maturing visual axis and the developing circadian rhythm. Consideration of the effects of light at night and insufficient light during the day should occur when giving anticipatory guidance in the care of newborn infants. Long-term health consequences of light imprinting may occur with inappropriate light-dark environments during the newborn period.
Address
Corporate Author Thesis
Publisher (down) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-9389 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2032
Permanent link to this record