toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Knutsson, A.; Alfredsson, L.; Karlsson, B.; Akerstedt, T.; Fransson, E.I.; Westerholm, P.; Westerlund, H. url  doi
openurl 
  Title Breast cancer among shift workers: results of the WOLF longitudinal cohort study Type Journal Article
  Year 2013 Publication Scandinavian Journal of Work, Environment & Health Abbreviated Journal Scand J Work Environ Health  
  Volume 39 Issue 2 Pages 170-177  
  Keywords (up) Adult; Aged; Breast Neoplasms/*epidemiology/etiology; Circadian Rhythm; Female; Humans; Incidence; Longitudinal Studies; Middle Aged; Proportional Hazards Models; Risk Assessment; Sweden/epidemiology; *Work Schedule Tolerance; oncogenesis  
  Abstract OBJECTIVE: The aim of this study was to investigate whether shift work (with or without night work) is associated with increased risk of breast cancer. METHODS: The population consisted of 4036 women. Data were obtained from WOLF (Work, Lipids, and Fibrinogen), a longitudinal cohort study. Information about baseline characteristics was based on questionnaire responses and medical examination. Cancer incidence from baseline to follow-up was obtained from the national cancer registry. Two exposure groups were identified: shift work with and without night work. The group with day work only was used as the reference group in the analysis. Cox regression analysis was used to calculate relative risk. RESULTS: In total, 94 women developed breast cancer during follow-up. The average follow-up time was 12.4 years. The hazard ratio for breast cancer was 1.23 [95% confidence interval (95% CI) 0.70-2.17] for shifts without night work and 2.02 (95% CI 1.03-3.95) for shifts with night work. When including only women <60 years of age, the risk estimates were 1.18 (95% CI 0.67-2.07) for shifts without night work, and 2.15 (95% CI 1.10-4.21) for shifts with night work. CONCLUSIONS: Our results indicate an increased risk for breast cancer among women who work shifts that includes night work.  
  Address Department of Health Sciences, Mid Sweden University, Sundsvall. Sweden. Anders.Knutsson@miun.se  
  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 0355-3140 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23007867 Approved no  
  Call Number IDA @ john @ Serial 154  
Permanent link to this record
 

 
Author Cajochen, C.; Altanay-Ekici, S.; Munch, M.; Frey, S.; Knoblauch, V.; Wirz-Justice, A. url  doi
openurl 
  Title Evidence that the lunar cycle influences human sleep Type Journal Article
  Year 2013 Publication Current Biology : CB Abbreviated Journal Curr Biol  
  Volume 23 Issue 15 Pages 1485-1488  
  Keywords (up) Adult; Aged; Cross-Sectional Studies; Electroencephalography; Female; Humans; Hydrocortisone/analysis/metabolism; Male; Melatonin/analysis/metabolism; Middle Aged; Moon; Nontherapeutic Human Experimentation; Periodicity; Saliva/metabolism; Sleep/*physiology; Sleep Stages/physiology; Young Adult  
  Abstract Endogenous rhythms of circalunar periodicity ( approximately 29.5 days) and their underlying molecular and genetic basis have been demonstrated in a number of marine species [1, 2]. In contrast, there is a great deal of folklore but no consistent association of moon cycles with human physiology and behavior [3]. Here we show that subjective and objective measures of sleep vary according to lunar phase and thus may reflect circalunar rhythmicity in humans. To exclude confounders such as increased light at night or the potential bias in perception regarding a lunar influence on sleep, we retrospectively analyzed sleep structure, electroencephalographic activity during non-rapid-eye-movement (NREM) sleep, and secretion of the hormones melatonin and cortisol found under stringently controlled laboratory conditions in a cross-sectional setting. At no point during and after the study were volunteers or investigators aware of the a posteriori analysis relative to lunar phase. We found that around full moon, electroencephalogram (EEG) delta activity during NREM sleep, an indicator of deep sleep, decreased by 30%, time to fall asleep increased by 5 min, and EEG-assessed total sleep duration was reduced by 20 min. These changes were associated with a decrease in subjective sleep quality and diminished endogenous melatonin levels. This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues.  
  Address Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4012 Basel, Switzerland. christian.cajochen@upkbs.ch  
  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 0960-9822 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23891110 Approved no  
  Call Number IDA @ john @ Serial 140  
Permanent link to this record
 

 
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 (up) 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 0021-972X ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22188742 Approved no  
  Call Number IDA @ john @ Serial 301  
Permanent link to this record
 

 
Author Figueiro, M.G.; Bierman, A.; Plitnick, B.; Rea, M.S. url  doi
openurl 
  Title Preliminary evidence that both blue and red light can induce alertness at night Type Journal Article
  Year 2009 Publication BMC Neuroscience Abbreviated Journal BMC Neurosci  
  Volume 10 Issue Pages 105  
  Keywords (up) Adult; Alpha Rhythm; Analysis of Variance; Beta Rhythm; Circadian Rhythm/*physiology; Cornea/physiology; Dose-Response Relationship, Radiation; Electrocardiography; Female; Humans; *Light; Male; Melatonin/secretion; Middle Aged; *Photic Stimulation; Psychomotor Performance; Radioimmunoassay; Salivary Glands/secretion; Wakefulness/*physiology; physiology of vision; blue light; red light  
  Abstract BACKGROUND: A variety of studies have demonstrated that retinal light exposure can increase alertness at night. It is now well accepted that the circadian system is maximally sensitive to short-wavelength (blue) light and is quite insensitive to long-wavelength (red) light. Retinal exposures to blue light at night have been recently shown to impact alertness, implicating participation by the circadian system. The present experiment was conducted to look at the impact of both blue and red light at two different levels on nocturnal alertness. Visually effective but moderate levels of red light are ineffective for stimulating the circadian system. If it were shown that a moderate level of red light impacts alertness, it would have had to occur via a pathway other than through the circadian system. METHODS: Fourteen subjects participated in a within-subject two-night study, where each participant was exposed to four experimental lighting conditions. Each night each subject was presented a high (40 lx at the cornea) and a low (10 lx at the cornea) diffuse light exposure condition of the same spectrum (blue, lambda(max) = 470 nm, or red, lambda(max) = 630 nm). The presentation order of the light levels was counterbalanced across sessions for a given subject; light spectra were counterbalanced across subjects within sessions. Prior to each lighting condition, subjects remained in the dark (< 1 lx at the cornea) for 60 minutes. Electroencephalogram (EEG) measurements, electrocardiogram (ECG), psychomotor vigilance tests (PVT), self-reports of sleepiness, and saliva samples for melatonin assays were collected at the end of each dark and light periods. RESULTS: Exposures to red and to blue light resulted in increased beta and reduced alpha power relative to preceding dark conditions. Exposures to high, but not low, levels of red and of blue light significantly increased heart rate relative to the dark condition. Performance and sleepiness ratings were not strongly affected by the lighting conditions. Only the higher level of blue light resulted in a reduction in melatonin levels relative to the other lighting conditions. CONCLUSION: These results support previous findings that alertness may be mediated by the circadian system, but it does not seem to be the only light-sensitive pathway that can affect alertness at night.  
  Address Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, USA. figuem@rpi.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 1471-2202 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19712442; PMCID:PMC2744917 Approved no  
  Call Number IDA @ john @ Serial 285  
Permanent link to this record
 

 
Author Dumont, M.; Lanctot, V.; Cadieux-Viau, R.; Paquet, J. url  doi
openurl 
  Title Melatonin production and light exposure of rotating night workers Type Journal Article
  Year 2012 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 29 Issue 2 Pages 203-210  
  Keywords (up) Adult; Animals; Circadian Rhythm/*physiology; Humans; *Light; Melatonin/*analogs & derivatives/*biosynthesis/urine; Neoplasms/etiology; *Photoperiod; Risk Factors; Sleep/physiology; *Work; Work Schedule Tolerance  
  Abstract Decreased melatonin production, due to acute suppression of pineal melatonin secretion by light exposure during night work, has been suggested to underlie higher cancer risks associated with prolonged experience of night work. However, the association between light exposure and melatonin production has never been measured in the field. In this study, 24-h melatonin production and ambulatory light exposure were assessed during both night-shift and day/evening-shift periods in 13 full-time rotating shiftworkers. Melatonin production was estimated with the excretion of urinary 6-sulfatoxymelatonin (aMT6s), and light exposure was measured with an ambulatory photometer. There was no difference in total 24-h aMT6s excretion between the two work periods. The night-shift period was characterized by a desynchrony between melatonin and sleep-wake rhythms, as shown by higher melatonin production during work and lower melatonin production during sleep when working night shifts than when working day/evening shifts. Light exposure during night work showed no correlation with aMT6s excreted during the night of work (p > .5), or with the difference in 24-h aMT6s excretion between the two work periods (p > .1). However, light exposure during night work was negatively correlated with total 24-h aMT6s excretion over the entire night-shift period (p < .01). In conclusion, there was no evidence of direct melatonin suppression during night work in this population. However, higher levels of light exposure during night work may have decreased total melatonin production, possibly by initiating re-entrainment and causing internal desynchrony. This interpretation is consistent with the proposition that circadian disruption, of which decreased melatonin production is only one of the adverse consequences, could be the mediator between night shiftwork and cancer risks.  
  Address Chronobiology Laboratory, Center for Advanced Research in Sleep Medicine, Sacre-Coeur Hospital of Montreal, Montreal, Quebec, Canada. marie.dumont@umontreal.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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22324558 Approved no  
  Call Number IDA @ john @ Serial 138  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: