toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Cho, J.R.; Joo, E.Y.; Koo, D.L.; Hong, S.B. url  doi
openurl 
  Title Let there be no light: the effect of bedside light on sleep quality and background electroencephalographic rhythms Type Journal Article
  Year 2013 Publication Sleep Medicine Abbreviated Journal Sleep Med  
  Volume 14 Issue 12 Pages 1422-1425  
  Keywords Eeg; Light; Polysomnography; Sleep; Sleep spindle; Slow oscillation  
  Abstract OBJECTIVES: Artificial lighting has been beneficial to society, but unnecessary light exposure at night may cause various health problems. We aimed to investigate how whole-night bedside light can affect sleep quality and brain activity. PATIENTS AND METHODS: Ten healthy sleepers underwent two polysomnography (PSG) sessions, one with the lights off and one with the lights on. PSG variables related to sleep quality were extracted and compared between lights-off and lights-on sleep. Spectral analysis was performed to rapid eye movement (REM) sleep and non-REM (NREM) sleep epochs to reveal any light-induced differences in background brain rhythms. RESULTS: Lights-on sleep was associated with increased stage 1 sleep (N1), decreased slow-wave sleep (SWS), and increased arousal index. Spectral analysis revealed that theta power (4-8Hz) during REM sleep and slow oscillation (0.5-1Hz), delta (1-4Hz), and spindle (10-16Hz) power during NREM sleep were decreased in lights-on sleep conditions. CONCLUSIONS: Sleeping with the light on not only causes shallow sleep and frequent arousals but also has a persistent effect on brain oscillations, especially those implicated in sleep depth and stability. Our study demonstrates additional hazardous effect of light pollution on health.  
  Address Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Samsung Biomedical Research Institute, Seoul, Republic of Korea; Division of Computation and Neural Systems, California Institute of Technology, Pasadena, California, USA  
  Corporate Author (up) 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:24210607 Approved no  
  Call Number IDA @ john @ Serial 141  
Permanent link to this record
 

 
Author Haus, E.L.; Smolensky, M.H. url  doi
openurl 
  Title Shift work and cancer risk: potential mechanistic roles of circadian disruption, light at night, and sleep deprivation Type Journal Article
  Year 2013 Publication Sleep Medicine Reviews Abbreviated Journal Sleep Med Rev  
  Volume 17 Issue 4 Pages 273-284  
  Keywords Cell Cycle/physiology; Circadian Rhythm/*physiology; Epigenesis, Genetic/physiology; Humans; Light; Melatonin/physiology; Neoplasms/*etiology; Risk Factors; Sleep Deprivation/*complications; Work Schedule Tolerance/*physiology; oncogenesis  
  Abstract Shift work that includes a nighttime rotation has become an unavoidable attribute of today's 24-h society. The related disruption of the human circadian time organization leads in the short-term to an array of jet-lag-like symptoms, and in the long-run it may contribute to weight gain/obesity, metabolic syndrome/type II diabetes, and cardiovascular disease. Epidemiologic studies also suggest increased cancer risk, especially for breast cancer, in night and rotating female shift workers. If confirmed in more controlled and detailed studies, the carcinogenic effect of night and shift work will constitute additional serious medical, economic, and social problems for a substantial proportion of the working population. Here, we examine the possible multiple and interconnected cancer-promoting mechanisms as a consequence of shift work, i.e., repeated disruption of the circadian system, pineal hormone melatonin suppression by exposure to light at night, sleep-deprivation-caused impairment of the immune system, plus metabolic changes favoring obesity and generation of proinflammatory reactive oxygen species.  
  Address Department of Laboratory Medicine & Pathology, University of Minnesota and Health Partners Medical Group, Regions Hospital, 640 Jackson Street, St. Paul, Minnesota 55101, USA. Erhard.X.Haus@HealthPartners.com  
  Corporate Author (up) 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:23137527 Approved no  
  Call Number IDA @ john @ Serial 157  
Permanent link to this record
 

 
Author Smith, M.R.; Revell, V.L.; Eastman, C.I. url  doi
openurl 
  Title Phase advancing the human circadian clock with blue-enriched polychromatic light Type Journal Article
  Year 2009 Publication Sleep Medicine Abbreviated Journal Sleep Med  
  Volume 10 Issue 3 Pages 287-294  
  Keywords Adult; Circadian Rhythm/*radiation effects; Female; Humans; *Light; Lighting/*methods; Male; Melatonin/metabolism; Phototherapy/*methods; Sleep; Wakefulness; Young Adult; blue light; sleep  
  Abstract BACKGROUND: Previous studies have shown that the human circadian system is maximally sensitive to short-wavelength (blue) light. Whether this sensitivity can be utilized to increase the size of phase shifts using light boxes and protocols designed for practical settings is not known. We assessed whether bright polychromatic lamps enriched in the short-wavelength portion of the visible light spectrum could produce larger phase advances than standard bright white lamps. METHODS: Twenty-two healthy young adults received either a bright white or bright blue-enriched 2-h phase advancing light pulse upon awakening on each of four treatment days. On the first treatment day the light pulse began 8h after the dim light melatonin onset (DLMO), on average about 2h before baseline wake time. On each subsequent day, light treatment began 1h earlier than the previous day, and the sleep schedule was also advanced. RESULTS: Phase advances of the DLMO for the blue-enriched (92+/-78 min, n=12) and white groups (76+/-45 min, n=10) were not significantly different. CONCLUSION: Bright blue-enriched polychromatic light is no more effective than standard bright light therapy for phase advancing circadian rhythms at commonly used therapeutic light levels.  
  Address Biological Rhythms Research Laboratory, Rush University Medical Center, Suite 425, 1645 W. Jackson Boulevard, Chicago, IL 60612, USA  
  Corporate Author (up) 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:18805055; PMCID:PMC2723863 Approved no  
  Call Number IDA @ john @ Serial 289  
Permanent link to this record
 

 
Author Sharkey, K.M.; Carskadon, M.A.; Figueiro, M.G.; Zhu, Y.; Rea, M.S. url  doi
openurl 
  Title Effects of an advanced sleep schedule and morning short wavelength light exposure on circadian phase in young adults with late sleep schedules Type Journal Article
  Year 2011 Publication Sleep Medicine Abbreviated Journal Sleep Med  
  Volume 12 Issue 7 Pages 685-692  
  Keywords Affect/physiology/radiation effects; Circadian Rhythm/*physiology/*radiation effects; Color; Dose-Response Relationship, Radiation; Female; Humans; *Light; Male; Melatonin/metabolism; Photoperiod; Phototherapy/*methods; Saliva/metabolism; Sleep/physiology/radiation effects; Sleep Disorders, Circadian Rhythm/prevention & control/*therapy; Stress, Psychological/prevention & control/therapy; Treatment Outcome; Young Adult; blue light  
  Abstract OBJECTIVE: We examined the effects of an advanced sleep/wake schedule and morning short wavelength (blue) light in 25 adults (mean age+/-SD=21.8+/-3 years; 13 women) with late sleep schedules and subclinical features of delayed sleep phase disorder (DSPD). METHODS: After a baseline week, participants kept individualized, fixed, advanced 7.5-h sleep schedules for 6days. Participants were randomly assigned to groups to receive “blue” (470nm, approximately 225lux, n=12) or “dim” (<1lux, n=13) light for 1h after waking each day. Head-worn “Daysimeters” measured light exposure; actigraphs and sleep diaries confirmed schedule compliance. Salivary dim light melatonin onset (DLMO), self-reported sleep, and mood were examined with 2x2 ANOVA. RESULTS: After 6days, both groups showed significant circadian phase advances, but morning blue light was not associated with larger phase shifts than dim-light exposure. The average DLMO advances (mean+/-SD) were 1.5+/-1.1h in the dim light group and 1.4+/-0.7h in the blue light group. CONCLUSIONS: Adherence to a fixed advanced sleep/wake schedule resulted in significant circadian phase shifts in young adults with subclinical DSPD with or without morning blue light exposure. Light/dark exposures associated with fixed early sleep schedules are sufficient to advance circadian phase in young adults.  
  Address Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Alpert Medical School of Brown University, Box G-RIH, Providence, RI 02912, USA. katherine_sharkey@brown.edu  
  Corporate Author (up) 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:21704557; PMCID:PMC3145013 Approved no  
  Call Number IDA @ john @ Serial 303  
Permanent link to this record
 

 
Author Kayaba, M.; Iwayama, K.; Ogata, H.; Seya, Y.; Tokuyama, K.; Satoh, M. url  doi
openurl 
  Title Drowsiness and low energy metabolism in the following morning induced by nocturnal blue light exposure Type Journal Article
  Year 2013 Publication Sleep Medicine Abbreviated Journal Sleep Medicine  
  Volume 14 Issue Pages e166-e167  
  Keywords blue light; light exposure; light at night; circadian disruption; drowsiness; melatonin; metabolism; sleep  
  Abstract Introduction

Evening light exposure debilitates the circadian rhythm and elicits sleep disturbance. Blue light peak wavelengths, around 460 nm, suppress melatonin secretion via the non-image-forming system. The effects of nocturnal blue light exposure on sleep have been reported to be specific but rather small (Münch, 2008). This study was designed to assess the effect of nocturnal blue light exposure on sleep and energy metabolism until noon the next day.

Materials and methods

Nine healthy male volunteers aged between 21 and 25 participated in this study which had a balanced cross-over design with intrasubject comparisons. After 2 h dark adaptation, the subjects were exposed to blue light or no light for 2 h. The peak wavelength of the blue LED was 465 nm, and the horizontal irradiance of the blue light at the height of eye was at 7.02fÊW/cm2. Sleep was recorded polysomnographically, and energy metabolism was measured with a whole body indirect calorimeter.

Results

There were no significant differences in sleep architecture and energy metabolism during the night. However, dozing (stages 1 and 2) was significantly higher (26.0 < 29.4 vs 6.3 < 8.1 min, P < 0.05), and energy expenditure, O2 consumption, CO2 production and the thermic effect of food (increase in energy expenditure after breakfast) were significantly lower the following morning in the blue light exposure subjects.

Conclusion

Contrary to our expectation, sleep architecture and energy metabolism during sleep were not affected by evening exposure to blue light. It might be due to our milder intervention by which subjects in a sitting position did not gaze at the light source set on the ceiling, while the subjects in previous studies directly received brighter light via custom built goggles (Cajochen, 2005; Münch, 2008) or gazed at a light source under the influence of mydriatic agents to dilate pupils (Brainard, 2001). New findings of the present study were that dozing (stages 1 and 2) was significantly increased, and energy metabolism was significantly lower the following morning in blue light exposed subjects. This suggests that modulation of the circadian rhythm is affected by nocturnal blue light exposure and the effect continues in the following daytime even if the intervention was mild.
 
  Address University of Tsukuba, Graduate School of Comprehensive Human Sciences, Japan  
  Corporate Author (up) Thesis  
  Publisher Place of Publication Editor  
  Language 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 Approved no  
  Call Number IDA @ john @ Serial 349  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: