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Author Chellappa, S.L.; Viola, A.U.; Schmidt, C.; Bachmann, V.; Gabel, V.; Maire, M.; Reichert, C.F.; Valomon, A.; Gotz, T.; Landolt, H.-P.; Cajochen, C. url  doi
openurl 
  Title Human melatonin and alerting response to blue-enriched light depend on a polymorphism in the clock gene PER3 Type Journal Article
  Year 2012 Publication The Journal of Clinical Endocrinology and Metabolism Abbreviated Journal J Clin Endocrinol Metab  
  Volume 97 Issue 3 Pages E433-7  
  Keywords Adult; Alleles; Cross-Over Studies; Female; Genotype; Homozygote; Humans; *Light; Male; Melatonin/*blood/genetics; *Minisatellite Repeats; Period Circadian Proteins/*genetics; *Polymorphism, Genetic; Questionnaires; Sleep/genetics; Wakefulness/*genetics  
  Abstract CONTEXT: Light exposure, particularly at the short-wavelength range, triggers several nonvisual responses in humans. However, the extent to which the melatonin-suppressing and alerting effect of light differs among individuals remains unknown. OBJECTIVE: Here we investigated whether blue-enriched polychromatic light impacts differentially on melatonin and subjective and objective alertness in healthy participants genotyped for the PERIOD3 (PER3) variable-number, tandem-repeat polymorphism. DESIGN, SETTING, AND PARTICIPANTS: Eighteen healthy young men homozygous for the PER3 polymorphism (PER3(5/5)and PER3(4/4)) underwent a balanced crossover design during the winter season, with light exposure to compact fluorescent lamps of 40 lux at 6500 K and at 2500 K during 2 h in the evening. RESULTS: In comparison to light at 2500 K, blue-enriched light at 6500 K induced a significant suppression of the evening rise in endogenous melatonin levels in PER3(5/5) individuals but not in PER3(4/4). Likewise, PER3(5/5) individuals exhibited a more pronounced alerting response to light at 6500 K than PER3(4/4) volunteers. Waking electroencephalographic activity in the theta range (5-7 Hz), a putative correlate of sleepiness, was drastically attenuated during light exposure at 6500 K in PER3(5/5) individuals as compared with PER3(4/4). CONCLUSIONS: We provide first evidence that humans homozygous for the PER3 5/5 allele are particularly sensitive to blue-enriched light, as indexed by the suppression of endogenous melatonin and waking theta activity. Light sensitivity in humans may be modulated by a clock gene polymorphism implicated in the sleep-wake regulation.  
  Address Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Wilhelm Kleinstrasse 27, CH-4012 Basel, Switzerland  
  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 (up) 0021-972X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22188742 Approved no  
  Call Number IDA @ john @ Serial 301  
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Author Kayumov, L.; Casper, R.F.; Hawa, R.J.; Perelman, B.; Chung, S.A.; Sokalsky, S.; Shapiro, C.M. url  doi
openurl 
  Title Blocking low-wavelength light prevents nocturnal melatonin suppression with no adverse effect on performance during simulated shift work Type Journal Article
  Year 2005 Publication The Journal of Clinical Endocrinology and Metabolism Abbreviated Journal J Clin Endocrinol Metab  
  Volume 90 Issue 5 Pages 2755-2761  
  Keywords Lighting; Adult; *Circadian Rhythm; Female; Humans; *Light; Male; Melatonin/*secretion; *Work Schedule Tolerance  
  Abstract Decreases in melatonin production in human and animals are known to be caused by environmental lighting, especially short-wavelength lighting (between 470 and 525 nm). We investigated the novel hypothesis that the use of goggles with selective exclusion of all wavelengths less than 530 nm could prevent the suppression of melatonin in bright-light conditions during a simulated shift-work experiment. Salivary melatonin levels were measured under dim (<5 lux), bright (800 lux), and filtered (800 lux) light at hourly intervals between 2000 and 0800 h in 11 healthy young males and eight females (mean age, 24.7 +/- 4.6 yr). The measurements were performed during three nonconsecutive nights over a 2-wk period. Subjective sleepiness was measured by self-report scales, whereas objective performance was assessed with the Continuous Performance Test. All subjects demonstrated preserved melatonin levels in filtered light similar to their dim-light secretion profile. Unfiltered bright light drastically suppressed melatonin production. Normalization of endogenous melatonin production while wearing goggles did not impair measures of performance, subjective sleepiness, or alertness.  
  Address Sleep Research Laboratory, Department of Psychiatry, University Health Network, ECW 3D-035, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8. lkayumov@uhnres.utoronto.ca  
  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 (up) 0021-972X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15713707 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 640  
Permanent link to this record
 

 
Author Cajochen, C.; Munch, M.; Kobialka, S.; Krauchi, K.; Steiner, R.; Oelhafen, P.; Orgul, S.; Wirz-Justice, A. url  doi
openurl 
  Title High sensitivity of human melatonin, alertness, thermoregulation, and heart rate to short wavelength light Type Journal Article
  Year 2005 Publication The Journal of Clinical Endocrinology and Metabolism Abbreviated Journal J Clin Endocrinol Metab  
  Volume 90 Issue 3 Pages 1311-1316  
  Keywords Human Health; Adult; Body Temperature Regulation/physiology/*radiation effects; Circadian Rhythm/physiology/radiation effects; Color; Heart Rate/physiology/*radiation effects; Humans; *Light; Male; Melatonin/*metabolism; Retinal Cone Photoreceptor Cells/physiology; Sleep Stages/physiology/radiation effects; Wakefulness/physiology/*radiation effects  
  Abstract Light can elicit acute physiological and alerting responses in humans, the magnitude of which depends on the timing, intensity, and duration of light exposure. Here, we report that the alerting response of light as well as its effects on thermoregulation and heart rate are also wavelength dependent. Exposure to 2 h of monochromatic light at 460 nm in the late evening induced a significantly greater melatonin suppression than occurred with 550-nm monochromatic light, concomitant with a significantly greater alerting response and increased core body temperature and heart rate ( approximately 2.8 x 10(13) photons/cm(2)/sec for each light treatment). Light diminished the distal-proximal skin temperature gradient, a measure of the degree of vasoconstriction, independent of wavelength. Nonclassical ocular photoreceptors with peak sensitivity around 460 nm have been found to regulate circadian rhythm function as measured by melatonin suppression and phase shifting. Our findings-that the sensitivity of the human alerting response to light and its thermoregulatory sequelae are blue-shifted relative to the three-cone visual photopic system-indicate an additional role for these novel photoreceptors in modifying human alertness, thermophysiology, and heart rate.  
  Address Centre for Chronobiology, Psychiatric University Clinic, Wilhelm Kleinstr. 27, CH-4025 Basel, Switzerland. christian.cajochen@pukbasel.ch  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0021-972X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15585546 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 728  
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Author Lockley, S.W.; Brainard, G.C.; Czeisler, C.A. url  doi
openurl 
  Title High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light Type Journal Article
  Year 2003 Publication The Journal of Clinical Endocrinology and Metabolism Abbreviated Journal J Clin Endocrinol Metab  
  Volume 88 Issue 9 Pages 4502-4505  
  Keywords Human Health; Adult; Area Under Curve; Circadian Rhythm/*radiation effects; Female; Humans; *Light; Male; Melatonin/*metabolism; Pineal Gland/metabolism/radiation effects; Saliva/metabolism; Non-programmatic  
  Abstract The endogenous circadian oscillator in mammals, situated in the suprachiasmatic nuclei, receives environmental photic input from specialized subsets of photoreceptive retinal ganglion cells. The human circadian pacemaker is exquisitely sensitive to ocular light exposure, even in some people who are otherwise totally blind. The magnitude of the resetting response to white light depends on the timing, intensity, duration, number and pattern of exposures. We report here that the circadian resetting response in humans, as measured by the pineal melatonin rhythm, is also wavelength dependent. Exposure to 6.5 h of monochromatic light at 460 nm induces a two-fold greater circadian phase delay than 6.5 h of 555 nm monochromatic light of equal photon density. Similarly, 460 nm monochromatic light causes twice the amount of melatonin suppression compared to 555 nm monochromatic light, and is dependent on the duration of exposure in addition to wavelength. These studies demonstrate that the peak of sensitivity of the human circadian pacemaker to light is blue-shifted relative to the three-cone visual photopic system, the sensitivity of which peaks at approximately 555 nm. Thus photopic lux, the standard unit of illuminance, is inappropriate when quantifying the photic drive required to reset the human circadian pacemaker.  
  Address Division of Sleep Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, Massachusetts 02115, USA  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0021-972X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12970330 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 778  
Permanent link to this record
 

 
Author Obayashi, K.; Saeki, K.; Kurumatani, N. url  doi
openurl 
  Title Ambient Light Exposure and Changes in Obesity Parameters: A Longitudinal Study of the HEIJO-KYO Cohort Type Journal Article
  Year 2016 Publication The Journal of Clinical Endocrinology and Metabolism Abbreviated Journal J Clin Endocrinol Metab  
  Volume Issue Pages jc20154123  
  Keywords Human Health  
  Abstract CONTEXT: Previous epidemiological studies have suggested an association between nighttime light levels and the prevalence of obesity, although evidence is limited to cross-sectional studies. OBJECTIVE: To evaluate the longitudinal association between ambient light exposure and the subsequent changes in obesity parameters. DESIGN AND PARTCIPANTS: Data from 1,110 elderly participants at baseline (mean age, 71.9 years) and data from 766 at follow-up (median, 21 months) were included in this prospective population-based study. MEASURES: Time-dependent ambient light exposure based on objective measurements and changes in the waist-to-height ratio (WHtR) and body mass index (BMI) were measured. RESULTS: Multivariable mixed-effect linear regression models showed a significant association between light exposure and the %WHtR gain; this was independent of potential confounders (e.g., caloric intake, physical activity, and sleep/wake parameters). Nighttime or evening exposure to higher light intensity was significantly associated with subsequent %WHtR gain. Morning exposure to a longer time >/=500 lux or nighttime exposure to a longer time <3 lux was significantly associated with subsequent %WHtR loss. These association trends were nearly consistent when the BMI was used as an obesity parameter. Increased nighttime light exposure (mean >/=3 vs. <3 lux) was estimated to correspond to a 10.2% WHtR gain and 10.0% increase in BMI over 10 years. CONCLUSIONS: Ambient light exposure, such as increased nighttime or evening light exposure and decreased morning light exposure, was independently associated with subsequent increases in obesity parameters. Further interventional studies are warranted to establish an optimal controlled lighting environment as a preventive option against obesity.  
  Address Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Nara, Japan  
  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 (up) 0021-972X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27383113 Approved no  
  Call Number LoNNe @ kyba @ Serial 1483  
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