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Haghani M, Abbasi S, Abdoli L, Shams SF, Baha'addini Baigy Zarandi BF, Shokrpour N, Jahromizadeh A, Mortazavi SA, Mortazavi SMJ. Blue Light and Digital Screens Revisited: A New Look at Blue Light from the Vision Quality, Circadian Rhythm and Cognitive Functions Perspective. J Biomed Phys Eng 2024; 14:213-228. [PMID: 39027713 PMCID: PMC11252550 DOI: 10.31661/jbpe.v0i0.2106-1355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/29/2021] [Indexed: 07/20/2024]
Abstract
Research conducted over the years has established that artificial light at night (ALAN), particularly short wavelengths in the blue region (~400-500 nm), can disrupt the circadian rhythm, cause sleep disturbances, and lead to metabolic dysregulation. With the increasing number of people spending considerable amounts of time at home or work staring at digital screens such as smartphones, tablets, and laptops, the negative impacts of blue light are becoming more apparent. While blue wavelengths during the day can enhance attention and reaction times, they are disruptive at night and are associated with a wide range of health problems such as poor sleep quality, mental health problems, and increased risk of some cancers. The growing global concern over the detrimental effects of ALAN on human health is supported by epidemiological and experimental studies, which suggest that exposure to ALAN is associated with disorders like type 2 diabetes, obesity, and increased risk of breast and prostate cancer. Moreover, several studies have reported a connection between ALAN, night-shift work, reduced cognitive performance, and a higher likelihood of human errors. The purpose of this paper is to review the biological impacts of blue light exposure on human cognitive functions and vision quality. Additionally, studies indicating a potential link between exposure to blue light from digital screens and increased risk of breast cancer are also reviewed. However, more research is needed to fully comprehend the relationship between blue light exposure and adverse health effects, such as the risk of breast cancer.
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Affiliation(s)
- Masoud Haghani
- Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Samaneh Abbasi
- Department of Medical Physics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Leila Abdoli
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyedeh Fatemeh Shams
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Nasrin Shokrpour
- School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Atefeh Jahromizadeh
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Seyed Mohammad Javad Mortazavi
- Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
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Cervera-Sánchez Z, Cacho-Martínez P, García-Muñoz Á. Efficacy of optometric phototherapy: a systematic review. JOURNAL OF OPTOMETRY 2023; 16:305-314. [PMID: 37230932 PMCID: PMC10518764 DOI: 10.1016/j.optom.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/14/2023] [Accepted: 03/21/2023] [Indexed: 05/27/2023]
Abstract
PURPOSE To analyse the scientific evidence about the efficacy of Syntonic phototherapy for producing changes in visual function. MATERIAL AND METHODS A systematic review was performed to obtain studies on the effects of Syntonic phototherapy on vision. A search in health science databases (Medline, Scopus, Web of Science and PsycINFO) for studies published between 1980 and 2022 was conducted in accordance with the principles of Cochrane approach. The search identified 197 articles. Only clinical studies which used the Syntonic phototherapy as a vision therapy for any visual condition were included. Clinical cases and case series were excluded. Following the inclusion criteria, 8 clinical studies met inclusion, 5 of them being pseudo-experimental studies with an equivalent control group and 3 pre-post pseudo-experimental studies. GRADE tool was used to assess the certainty of the evidence of the studies. The GRADE evidence profile for the studies through the Soft table was made to analyse data. RESULTS The studies analysed seven outcomes: visual symptoms, functional visual fields, visual acuity, contrast sensitivity, deviation (phoria/tropia), stereopsis and reading abilities. Finding table about results (Soft Table) showed that for all outcomes reviewed, all studies yielded very low certainty of evidence. Results revealed a lack of scientific evidence of the efficacy of Syntonic optometric phototherapy to produce changes in the visual function. CONCLUSION This systematic review found no consistent evidence for the efficacy of Syntonic phototherapy to cause changes in visual function. There is no scientific evidence to support its clinical use for treating any type of visual anomalies.
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Affiliation(s)
- Zaíra Cervera-Sánchez
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain
| | - Pilar Cacho-Martínez
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain.
| | - Ángel García-Muñoz
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain
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Zhang Y, Murphy J, Lammers-van der Holst HM, Barger LK, Lai YJ, Duffy JF. Interventions to improve the sleep of nurses: A systematic review. Res Nurs Health 2023; 46:462-484. [PMID: 37710916 PMCID: PMC10539041 DOI: 10.1002/nur.22337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/03/2023] [Accepted: 08/18/2023] [Indexed: 09/16/2023]
Abstract
Nurses are at a high risk for short sleep duration and poor sleep quality due to irregular work schedules and high occupational stress. Considering the effect of nurses' sleep on the safety and health of themselves and their patients, it is important to promote healthy sleep for nurses. We sought to synthesize the published experimental and quasi-experimental studies that address interventions to improve sleep in nurses. A systematic search was conducted for studies published in English up until May 15, 2023, using the databases PubMed, CINAHL, Academic Search Ultimate, and PsycINFO. In total, 38 articles were included, covering 22 experimental and 16 quasi-experimental studies with sample sizes ranging from 9 to 207. Studies were assessed using the Cochrane Risk of Bias tool and considered as low to medium quality. Thirty-six of the 38 studies reported positive findings for at least one sleep outcome. Intervention types included aroma therapy, dietary supplements, cognitive behavioral therapy, light therapy, mind-body therapy, sleep education, exercise, napping, shift schedule modification, and multicomponent intervention, all of which showed moderate effectiveness in promoting sleep outcomes of nurses. Comparing and contrasting studies on specific interventions for improving sleep in nurses is sparse and often equivocal. With the variations of research methodology and outcome measures, it is difficult to make a conclusion about each intervention's effectiveness on specific sleep outcomes. Additional high-quality research, including randomized controlled trials, is needed to evaluate strategies for improving sleep in this unique, safety-sensitive occupational group.
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Affiliation(s)
- Yuan Zhang
- Solomont School of Nursing, Zuckerberg College of Health Sciences, University of Massachusetts Lowell, Lowell, MA 01854
| | - Jennifer Murphy
- Solomont School of Nursing, Zuckerberg College of Health Sciences, University of Massachusetts Lowell, Lowell, MA 01854
| | | | - Laura K. Barger
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Boston, MA 02115
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115
| | - Yun-Ju Lai
- Solomont School of Nursing, Zuckerberg College of Health Sciences, University of Massachusetts Lowell, Lowell, MA 01854
| | - Jeanne F. Duffy
- Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Boston, MA 02115
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115
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Jeon BM, Kim SH, Shin SH. Effectiveness of sleep interventions for rotating night shift workers: a systematic review and meta-analysis. Front Public Health 2023; 11:1187382. [PMID: 37427284 PMCID: PMC10323438 DOI: 10.3389/fpubh.2023.1187382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/06/2023] [Indexed: 07/11/2023] Open
Abstract
Background Sleep disturbance is a common issue among rotating night shift workers and is closely related to health risks. The present study aimed to determine the effectiveness of pharmacological and non-pharmacological sleep interventions for the management of sleep disturbance among rotating night shift workers. Methods For this systematic review and meta-analysis, we searched six electronic databases-EMBASE, CINAHL, Cochrane Library, PubMed, Scopus, and Web of Science-for randomized controlled trials and clinical trials published from January 1990 to June 2022. The quality of eligible studies was independently assessed by three authors using the Joanna Briggs Institute Critical Appraisal Checklist for randomized controlled trials and quasi-experimental studies. The meta-analysis was performed based on the random effects model using the Comprehensive Meta-Analysis software. The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results Of the 1019 studies retrieved, 30 met the inclusion criteria for the systematic review; 25 were selected for the meta-analysis. Sleep interventions were categorized as follows: pharmacological approach (n = 7), light therapy (n = 9), cognitive behavioral approach (n = 7), aroma or alternative therapy (n = 4), and shift schedule modification (n = 3). The overall mean effect size of the interventions was moderate (Hedges' g = 0.59; 95% confidence interval = 0.33-0.84, z = 4.50, p < 0.001). Conclusion Sleep interventions were effective in promoting sleep or reducing sleep disturbance among rotating night shift workers. These findings provide evidence of the effectiveness of various pharmacological and non-pharmacological sleep interventions for managing sleep health in the work environment of rotating night shift workers.
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Affiliation(s)
- Bo Min Jeon
- College of Nursing, Kyungpook National University, Daegu, Republic of Korea
| | - Su Hyun Kim
- College of Nursing, The Research Institute of Nursing Science, Kyungpook National University, Daegu, Republic of Korea
| | - Seung Hwa Shin
- Department of Nursing, Andong Science College, Andong, Republic of Korea
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Bijnens S, Depoortere I. Controlled light exposure and intermittent fasting as treatment strategies for metabolic syndrome and gut microbiome dysregulation in night shift workers. Physiol Behav 2023; 263:114103. [PMID: 36731762 DOI: 10.1016/j.physbeh.2023.114103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/09/2023] [Accepted: 01/28/2023] [Indexed: 02/01/2023]
Abstract
The mammalian circadian clocks are entrained by environmental time cues, such as the light-dark cycle and the feeding-fasting cycle. In modern society, circadian misalignment is increasingly more common under the guise of shift work. Shift workers, accounting for roughly 20% of the workforce population, are more susceptible to metabolic disease. Exposure to artificial light at night and eating at inappropriate times of the day uncouples the central and peripheral circadian clocks. This internal circadian desynchrony is believed to be one of the culprits leading to metabolic disease. In this review, we discuss how alterations in the rhythm of gut microbiota and their metabolites during chronodisruption send conflicting signals to the host, which may ultimately contribute to disturbed metabolic processes. We propose two behavioral interventions to improve health in shift workers. Firstly, by carefully timing the moments of exposure to blue light, and hence shifting the melatonin peak, to improve sleep quality of daytime sleeping episodes. Secondly, by timing the daily time window of caloric intake to the biological morning, to properly align the feeding-fasting cycle with the light-dark cycle and to reduce the risk of metabolic disease. These interventions can be a first step in reducing the worldwide burden of health problems associated with shift work.
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Affiliation(s)
- Sofie Bijnens
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium
| | - Inge Depoortere
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders, University of Leuven, Leuven, Belgium.
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Pun TB, Phillips CL, Marshall NS, Comas M, Hoyos CM, D’Rozario AL, Bartlett DJ, Davis W, Hu W, Naismith SL, Cain S, Postnova S, Grunstein RR, Gordon CJ. The Effect of Light Therapy on Electroencephalographic Sleep in Sleep and Circadian Rhythm Disorders: A Scoping Review. Clocks Sleep 2022; 4:358-373. [PMID: 35997384 PMCID: PMC9397048 DOI: 10.3390/clockssleep4030030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 07/21/2022] [Accepted: 08/02/2022] [Indexed: 01/27/2023] Open
Abstract
Light therapy is used to treat sleep and circadian rhythm disorders, yet there are limited studies on whether light therapy impacts electroencephalographic (EEG) activity during sleep. Therefore, we aimed to provide an overview of research studies that examined the effects of light therapy on sleep macro- and micro-architecture in populations with sleep and circadian rhythm disorders. We searched for randomized controlled trials that used light therapy and included EEG sleep measures using MEDLINE, PubMed, CINAHL, PsycINFO and Cochrane Central Register of Controlled Trials databases. Five articles met the inclusion criteria of patients with either insomnia or delayed sleep−wake phase disorder (DSWPD). These trials reported sleep macro-architecture outcomes using EEG or polysomnography. Three insomnia trials showed no effect of the timing or intensity of light therapy on total sleep time, wake after sleep onset, sleep efficiency and sleep stage duration compared to controls. Only one insomnia trial reported significantly higher sleep efficiency after evening light therapy (>4000 lx between 21:00−23:00 h) compared with afternoon light therapy (>4000 lx between 15:00−17:00 h). In the only DSWPD trial, six multiple sleep latency tests were conducted across the day (09:00 and 19:00 h) and bright light (2500 lx) significantly lengthened sleep latency in the morning (09:00 and 11:00 h) compared to control light (300 lx). None of the five trials reported any sleep micro-architecture measures. Overall, there was limited research about the effect of light therapy on EEG sleep measures, and studies were confined to patients with insomnia and DSWPD only. More research is needed to better understand whether lighting interventions in clinical populations affect sleep macro- and micro-architecture and objective sleep timing and quality.
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Affiliation(s)
- Teha B. Pun
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Craig L. Phillips
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Nathaniel S. Marshall
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Maria Comas
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Camilla M. Hoyos
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Angela L. D’Rozario
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Delwyn J. Bartlett
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Wendy Davis
- School of Architecture, Design and Planning, The University of Sydney, Sydney, NSW 2008, Australia
| | - Wenye Hu
- School of Architecture, Design and Planning, The University of Sydney, Sydney, NSW 2008, Australia
| | - Sharon L. Naismith
- Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Sean Cain
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC 3800, Australia
| | - Svetlana Postnova
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- School of Physics, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ron R. Grunstein
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Sleep and Severe Mental Illness Clinic, CPC-RPA Clinic, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia
| | - Christopher J. Gordon
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Correspondence: ; Tel.: +61-2-9351-0586
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Boivin DB, Boudreau P, Kosmadopoulos A. Disturbance of the Circadian System in Shift Work and Its Health Impact. J Biol Rhythms 2021; 37:3-28. [PMID: 34969316 PMCID: PMC8832572 DOI: 10.1177/07487304211064218] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The various non-standard schedules required of shift workers force abrupt changes in the timing of sleep and light-dark exposure. These changes result in disturbances of the endogenous circadian system and its misalignment with the environment. Simulated night-shift experiments and field-based studies with shift workers both indicate that the circadian system is resistant to adaptation from a day- to a night-oriented schedule, as determined by a lack of substantial phase shifts over multiple days in centrally controlled rhythms, such as those of melatonin and cortisol. There is evidence that disruption of the circadian system caused by night-shift work results not only in a misalignment between the circadian system and the external light-dark cycle, but also in a state of internal desynchronization between various levels of the circadian system. This is the case between rhythms controlled by the central circadian pacemaker and clock genes expression in tissues such as peripheral blood mononuclear cells, hair follicle cells, and oral mucosa cells. The disruptive effects of atypical work schedules extend beyond the expression profile of canonical circadian clock genes and affects other transcripts of the human genome. In general, after several days of living at night, most rhythmic transcripts in the human genome remain adjusted to a day-oriented schedule, with dampened group amplitudes. In contrast to circadian clock genes and rhythmic transcripts, metabolomics studies revealed that most metabolites shift by several hours when working nights, thus leading to their misalignment with the circadian system. Altogether, these circadian and sleep-wake disturbances emphasize the all-encompassing impact of night-shift work, and can contribute to the increased risk of various medical conditions. Here, we review the latest scientific evidence regarding the effects of atypical work schedules on the circadian system, sleep and alertness of shift-working populations, and discuss their potential clinical impacts.
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Affiliation(s)
- Diane B Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Philippe Boudreau
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Anastasi Kosmadopoulos
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
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Shin S, Kim SH, Jeon B. Objective Assessment of Sleep Patterns among Night-Shift Workers: A Scoping Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182413236. [PMID: 34948844 PMCID: PMC8701940 DOI: 10.3390/ijerph182413236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/03/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022]
Abstract
In this scoping review of the literature, we identified the types and the parameters of objective measurements to assess sleep patterns among night-shift workers. We conducted a literature search using electronic databases for studies published from 1991 to 2020 and charted and summarized key information. We included 32 studies in the review. Polysomnography was used in 6 studies and wearable sleep detection devices were utilized in 26 studies. The duration of sleep assessment using the wearable devices ranged from 1 day to ≥4 weeks, and more than half of the studies collected data for >2 weeks. The majority of the studies used subjective questionnaires, such as the Karolinska Sleepiness Scale, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index, in addition to objective sleep measurements. Total sleep time was the most common parameter, followed by sleep efficiency, sleep onset latency, and time or frequency of being awake. As the utilization of wearable devices to assess the sleep patterns of night-shift workers is expected to increase, further evaluation of device accuracy and precision, optimal data collection period, and key parameters is warranted.
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Affiliation(s)
- Seunghwa Shin
- Department of Nursing, Andong Science College, Kyungpook, Andong 36616, Korea;
| | - Su-Hyun Kim
- College of Nursing, Kyungpook National University, Daegu 41944, Korea;
- Research Institute of Nursing Science, College of Nursing, Kyungpook National University, Gukchaebosang-ro 680, Daegu 41944, Korea
- Correspondence: ; Tel.: +82-53-420-4928; Fax: +82-53-421-2758
| | - Bomin Jeon
- College of Nursing, Kyungpook National University, Daegu 41944, Korea;
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9
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Harrison EM, Schmied EA, Yablonsky AM, Glickman GL. Implementation of interventions designed to promote healthy sleep and circadian rhythms in shiftworkers. Chronobiol Int 2020; 38:467-479. [PMID: 33327802 DOI: 10.1080/07420528.2020.1845190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Shiftwork is a significant risk factor for a host of negative health and safety outcomes, which have been at least partly attributed to disturbances of the circadian timing system. As a result, an entire sub-field of chronobiology has been devoted to developing and evaluating countermeasures for circadian misalignment, sleep disruption, fatigue, and other issues associated with shiftwork. Much of this research takes place under highly controlled laboratory conditions due to the necessity of accurately characterizing individual rhythms, both for intervention design and assessment of efficacy. Applied studies of interventions for shiftworkers are, by their nature, more complicated, often demonstrating less consistent findings. While this, in part, reflects execution under less rigorously controlled conditions, it may also stem from variability in implementation approaches. A systematic review of published studies (through May 2017) of interventions designed to enhance circadian health in shiftworkers was conducted to determine the frequency and quality of the assessment of implementation as well as barriers and enablers to implementation. A search of PubMed, PsychINFO, Web of Science, and CINAHL databases yielded a total of 5368 unique references. After a title and abstract screen, 323 proceeded to full-text review; 68 of those met final criteria for data extraction. Implementation was assessed to some degree in 60.3% of those 68 articles. Where it was assessed, the mean quality score on a scale from 1 to 5 (1 = very little, 3 = moderate, 5 = very in-depth) was 2.56. One or more enablers were identified in just 17 of the 68 studies (25.0%), and barriers in just 18 (26.5%). Implementation of these interventions is a critical but seldom-acknowledged component of their uptake and effectiveness, and we highly recommend that future shiftworker intervention research make an effort to incorporate formalized assessments of implementation and/or hybrid effectiveness-implementation approaches.
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Affiliation(s)
- Elizabeth M Harrison
- Center for Circadian Biology, University of California San Diego, La Jolla, CA, USA.,Leidos, Inc., San Diego, CA, USA.,Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, USA
| | - Emily A Schmied
- Leidos, Inc., San Diego, CA, USA.,Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, USA.,School of Public Health, San Diego State University, San Diego, CA, USA
| | - Abigail M Yablonsky
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, USA.,Directorate for Professional Education, Naval Medical Center San Diego, San Diego, CA, USA
| | - Gena L Glickman
- Center for Circadian Biology, University of California San Diego, La Jolla, CA, USA.,Department of Psychiatry and Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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Schilperoort M, Rensen PCN, Kooijman S. Time for Novel Strategies to Mitigate Cardiometabolic Risk in Shift Workers. Trends Endocrinol Metab 2020; 31:952-964. [PMID: 33183967 DOI: 10.1016/j.tem.2020.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/15/2022]
Abstract
Circadian disruption induced by shift work is robustly associated with obesity, diabetes, and cardiovascular disease in humans. Less well-known are the mechanisms underlying these associations, and the effectiveness of strategies to reduce cardiometabolic risk in the shift work population. In this review, the different ways in which shift work can deteriorate cardiometabolic health, and how to use this information to reflect on various risk-mitigating strategies, is discussed. While individual strategies appear promising in animal studies, the multifactorial disease risk in shift workers likely requires a multidisciplinary approach. Therefore, the need for individually-tailored combined lifestyle interventions, that could be essential in reducing cardiometabolic disorders in the large population of shift workers in our 24/7 society, is argued.
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Affiliation(s)
- Maaike Schilperoort
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, The Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Albinusdreef 2, 2333ZA Leiden, The Netherlands
| | - Patrick C N Rensen
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, The Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Albinusdreef 2, 2333ZA Leiden, The Netherlands
| | - Sander Kooijman
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, The Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Albinusdreef 2, 2333ZA Leiden, The Netherlands.
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11
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Electrochromic selective filtering of chronodisruptive visible wavelengths. PLoS One 2020; 15:e0241900. [PMID: 33152042 PMCID: PMC7643985 DOI: 10.1371/journal.pone.0241900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/22/2020] [Indexed: 01/20/2023] Open
Abstract
We present evidence of pupil response modification, as well as differential theoretical melatonin suppression through selective and dynamic electrochromic filtering of visible light in the 400-500 nm range to minimize chronodisruptive nocturnal blue light exposure. A lower activation of intrinsically photosensitive retinal ganglion cells (ipRGCs), the first step for light to reach a human's internal clock, is related to melatonin secretion therefore avoiding detrimental effects of excessive blue light exposure. Pupillary Light Reflex and Color Naming were experimentally assessed under light filtered by two different coloration states (transmissive and absorptive) of these novel dynamic filters, plus an uncoated test device, in 16 volunteers. Also, different commercial light sources at illuminances ranging from 1 to 1000 lux were differentially filtered and compared in terms of theoretical melatonin suppression. Representative parameters of the pupil responses reflected lower pupil constriction when the electrochromic filters (ECFs) were switched on (absorptive state, blue light is absorbed by the filter) compared to uncoated filters (control sample), but failed to do so under transmissive state (blue light passes through the filter) indicating less activation of ipRGCs under absorptive state (although no significant differences between states was found). Out of eight colors tested, just one showed significant differences in naming between both filter states. Thus, the ECF would have some protecting effect on ipRGC activation with very limited changes in color perception. While there are some limitations of the theoretical model used, the absorptive state yielded significantly lower theoretical melatonin suppression in all those light sources containing blue wavelengths across the illuminance range tested. This would open the way for further research on biological applications of electrochromic devices.
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van Woerkom M. A quasi-experimental study into the effects of naps and therapy glasses on fatigue and well-being. J Nurs Manag 2020; 29:562-571. [PMID: 33029828 PMCID: PMC8247279 DOI: 10.1111/jonm.13172] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 02/02/2023]
Abstract
Aim To investigate the effects of a napping facility and therapy glasses on fatigue and well‐being at the end of the night shift. Background Night shift work has adverse effects on fatigue and well‐being. Methods A quasi‐experimental study was conducted, and data were collected on 243 night shifts of 95 nurses who had either access to a napping facility, therapy glasses, both facilities or no facilities. Multilevel analyses were conducted to predict fatigue and well‐being. Results Night shifts of nurses having access to both facilities were associated with less fatigue and more well‐being. The use of therapy glasses related negatively to fatigue and positively to well‐being. The use of the napping facility was not associated with fatigue and well‐being. However, having slept while napping and sleeping time during napping were negatively associated with fatigue and positively associated with well‐being. Conclusion Therapy glasses and sleeping in a napping facility can be effective interventions in reducing the adverse effects of night shift work. Implications for Nursing Management Therapy glasses seem an effective investment to facilitate the well‐being of nurses. To enhance sleeping during napping, it is worthwhile to let nurses get accustomed to the napping facility and customize settings to personal preferences.
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Affiliation(s)
- Marianne van Woerkom
- Department of Human Resource Studies, Tilburg University, Tilburg, The Netherlands.,Department of Psychology, Education and Child Studies, Erasmus University Rotterdam, Rotterdam, The Netherlands
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13
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Hou Y, Liu L, Chen X, Li Q, Li J. Association between circadian disruption and diseases: A narrative review. Life Sci 2020; 262:118512. [PMID: 33010281 DOI: 10.1016/j.lfs.2020.118512] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 09/15/2020] [Accepted: 09/24/2020] [Indexed: 02/06/2023]
Abstract
Circadian rhythms play an important role in a wide range of human physiology and pathology. Individuals increasingly experience situations such as night-shift work schedules, likely leading to circadian disruption. Recent studies have also demonstrated that patients with other diseases often show symptoms of circadian disruption as manifested by the sleep-wake cycle and other biological rhythms. Circadian disruption often results in changes to the phase, period, and amplitude of the sleep-wake cycle, melatonin rhythm, and core body temperature. Several cardiometabolic, psychiatric, and neurodegenerative diseases are closely related to circadian disruption. Several interventions are also available, including phototherapy, exogenous melatonin, and exercise. The cumulative findings suggest that circadian disruption can increase risk for some cardiometabolic diseases. Circadian disruption also acts as a concomitant symptom of several psychiatric and neurodegenerative diseases. More attention should be paid to evaluating the impact of circadian disruption on these related diseases, as well as the benefits of the mitigation interventions for both circadian disruption and related diseases.
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Affiliation(s)
- Yuchao Hou
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Lumin Liu
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Xiaotong Chen
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Qi Li
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Jing Li
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China.
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14
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Improving fatigue risk management in healthcare: A scoping review of sleep-related/ fatigue-management interventions for nurses and midwives (reprint). Int J Nurs Stud 2020; 112:103745. [PMID: 32847675 DOI: 10.1016/j.ijnurstu.2020.103745] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Nurses and midwives make up almost 50% of the global healthcare shift working workforce. Shift work interferes with sleep and causes fatigue with adverse effects for nurses' and midwives' health, as well as on patient safety and care. Where other safety-critical sectors have developed Fatigue Risk Management Systems, healthcare is behind the curve; with published literature only focussing on the evaluation of discreet sleep-related/fatigue-management interventions. Little is known, however, about which interventions have been evaluated for nurses and midwives. Our review is a critical first step to building the evidence-base for healthcare organisations seeking to address this important operational issue. OBJECTIVES We address two questions: (1) what sleep-related/fatigue-management interventions have been assessed in nurses and midwives and what is their evidence-base? and (2) what measures are used by researchers to assess intervention effectiveness? DESIGN AND DATA SOURCES The following databases were searched in November, 2018 with no limit on publication dates: MEDLINE, PsychINFO and CINAHL. REVIEW METHODS We included: (1) studies conducted in adult samples of nurses and/or midwives that had evaluated a sleep-related/fatigue-management intervention; and (2) studies that reported intervention effects on fatigue, sleep, or performance at work, and on measures of attention or cognitive performance (as they relate to the impact of shift working on patient safety/care). RESULTS The search identified 798 potentially relevant articles, out of which 32 met our inclusion criteria. There were 8619 participants across the included studies and all were nurses (88.6% female). We did not find any studies conducted in midwives nor any studies conducted in the UK, with most studies conducted in the US, Italy and Taiwan. There was heterogeneity both in terms of the interventions evaluated and the measures used to assess effectiveness. Napping could be beneficial but there was wide variation regarding nap duration and timing, and we need to understand more about barriers to implementation. Longer shifts, shift patterns including nights, and inadequate recovery time between shifts (quick returns) were associated with poorer sleep, increased sleepiness and increased levels of fatigue. Light exposure and/or light attenuation interventions showed promise but the literature was dominated by small, potentially unrepresentative samples. CONCLUSIONS The literature related to sleep-related/fatigue-management interventions for nurses and midwives is fragmented and lacks cohesion. Further empirical work is warranted with a view to developing comprehensive Fatigue Risk Management Systems to protect against fatigue in nurses, midwives, and other shift working healthcare staff.
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15
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LaPlaca DA, Turner H. Health Ramifications of Smart Devices. Strength Cond J 2020. [DOI: 10.1519/ssc.0000000000000535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Spitschan M, Lazar R, Cajochen C. Visual and non-visual properties of filters manipulating short-wavelength light. Ophthalmic Physiol Opt 2020; 39:459-468. [PMID: 31696535 PMCID: PMC6887545 DOI: 10.1111/opo.12648] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/26/2019] [Indexed: 12/14/2022]
Abstract
Purpose Optical filters and tints manipulating short‐wavelength light (sometimes called ‘blue‐blocking’ or ‘blue‐attenuating’ filters) are used in the management of a range of ocular, retinal, neurological and psychiatric disorders. In many cases, the only available quantification of the optical effects of a given optical filter is the spectral transmittance, which specifies the amount of light transmitted as a function of wavelength. Methods We propose a novel physiologically relevant and retinally referenced framework for quantifying the visual and non‐visual effects of these filters, incorporating the attenuation of luminance (luminous transmittance), the attenuation of melanopsin activation (melanopsin transmittance), the colour shift, and the reduction of the colour gamut (gamut reduction). Using these criteria, we examined a novel database of spectral transmittance functions of optical filters (n = 121) which were digitally extracted from a variety of sources. Results We find a large diversity in the alteration of visual and non‐visual properties. The spectral transmittance properties of the examined filters vary widely, in terms of shapes and cut‐off wavelengths. All filters show relatively more melanopsin attenuation than luminance attenuation (lower melanopsin transmittance than luminous transmittance). Across the data set, we find that melanopsin transmittance and luminous transmittance are correlated. Conclusions We suggest that future studies and examinations of the physiological effects of optical filters quantify the visual and non‐visual effects of the filters beyond the spectral transmittance, which will eventually aid in developing a mechanistic understanding of how different filters affect physiology. We strongly discourage comparing the downstream effects of different filters on, e.g. sleep or circadian responses, without considering their effects on the retinal stimulus.
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Affiliation(s)
- Manuel Spitschan
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Centre for Chronobiology, Psychiatric Hospital of the University of Basel (UPK), Basel, Switzerland.,Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
| | - Rafael Lazar
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel (UPK), Basel, Switzerland.,Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel (UPK), Basel, Switzerland.,Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
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17
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Querstret D, O'Brien K, Skene DJ, Maben J. Improving fatigue risk management in healthcare: A systematic scoping review of sleep-related/fatigue-management interventions for nurses and midwives. Int J Nurs Stud 2019; 106:103513. [PMID: 32283414 DOI: 10.1016/j.ijnurstu.2019.103513] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 12/04/2019] [Accepted: 12/24/2019] [Indexed: 01/13/2023]
Abstract
BACKGROUND Nurses and midwives make up almost 50% of the global healthcare shift working workforce. Shift work interferes with sleep and causes fatigue with adverse effects for nurses' and midwives' health, as well as on patient safety and care. Where other safety-critical sectors have developed Fatigue Risk Management Systems, healthcare is behind the curve; with published literature only focussing on the evaluation of discreet sleep-related/fatigue-management interventions. Little is known, however, about which interventions have been evaluated for nurses and midwives. Our review is a critical first step to building the evidence-base for healthcare organisations seeking to address this important operational issue. OBJECTIVES We address two questions: (1) what sleep-related/fatigue-management interventions have been assessed in nurses and midwives and what is their evidence-base? and (2) what measures are used by researchers to assess intervention effectiveness? DESIGN AND DATA SOURCES The following databases were searched in November, 2018 with no limit on publication dates: MEDLINE, PsychINFO and CINAHL. REVIEW METHODS We included: (1) studies conducted in adult samples of nurses and/or midwives that had evaluated a sleep-related/fatigue-management intervention; and (2) studies that reported intervention effects on fatigue, sleep, or performance at work, and on measures of attention or cognitive performance (as they relate to the impact of shift working on patient safety/care). RESULTS The search identified 798 potentially relevant articles, out of which 32 met our inclusion criteria. There were 8619 participants across the included studies and all were nurses (88.6% female). We did not find any studies conducted in midwives nor any studies conducted in the UK, with most studies conducted in the US, Italy and Taiwan. There was heterogeneity both in terms of the interventions evaluated and the measures used to assess effectiveness. Napping could be beneficial but there was wide variation regarding nap duration and timing, and we need to understand more about barriers to implementation. Longer shifts, shift patterns including nights, and inadequate recovery time between shifts (quick returns) were associated with poorer sleep, increased sleepiness and increased levels of fatigue. Light exposure and/or light attenuation interventions showed promise but the literature was dominated by small, potentially unrepresentative samples. CONCLUSIONS The literature related to sleep-related/fatigue-management interventions for nurses and midwives is fragmented and lacks cohesion. Further empirical work is warranted with a view to developing comprehensive Fatigue Risk Management Systems to protect against fatigue in nurses, midwives, and other shift working healthcare staff.
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Affiliation(s)
- Dawn Querstret
- Faculty of Sport, Health and Applied Science, St Mary's University, London TW1 4SX, UK.
| | - Katie O'Brien
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7YH, UK
| | - Debra J Skene
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7YH, UK
| | - Jill Maben
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7YH, UK
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18
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Gladanac B, Jonkman J, Shapiro CM, Brown TJ, Ralph MR, Casper RF, Rahman SA. Removing Short Wavelengths From Polychromatic White Light Attenuates Circadian Phase Resetting in Rats. Front Neurosci 2019; 13:954. [PMID: 31551702 PMCID: PMC6746919 DOI: 10.3389/fnins.2019.00954] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/23/2019] [Indexed: 11/13/2022] Open
Abstract
Visible light is the principal stimulus for resetting the mammalian central circadian pacemaker. Circadian phase resetting is most sensitive to short-wavelength (blue) visible light. We examined the effects of removing short-wavelengths < 500 nm from polychromatic white light using optical filters on circadian phase resetting in rats. Under high irradiance conditions, both long- (7 h) and short- (1 h) duration short-wavelength filtered (< 500 nm) light exposure attenuated phase-delay shifts in locomotor activity rhythms by (∼40-50%) as compared to unfiltered light exposure. However, there was no attenuation in phase resetting under low irradiance conditions. Additionally, the reduction in phase-delay shifts corresponded to regionally specific attenuation in molecular markers of pacemaker activation in response to light exposure, including c-FOS, Per1 and Per2. These results demonstrate that removing short-wavelengths from polychromatic white light can attenuate circadian phase resetting in an irradiance dependent manner. These results have important implications for designing and optimizing lighting interventions to enhance circadian adaptation.
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Affiliation(s)
- Bojana Gladanac
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - James Jonkman
- Advanced Optical Microscopy Facility, University Health Network, Toronto, ON, Canada
| | - Colin M Shapiro
- Department of Psychiatry and Ophthalmology, University of Toronto, Toronto, ON, Canada.,Youthdale Child and Adolescent Sleep Centre, Toronto, ON, Canada
| | - Theodore J Brown
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Division of Reproductive Endocrinology and Infertility, University of Toronto, Toronto, ON, Canada
| | - Martin R Ralph
- Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Robert F Casper
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Division of Reproductive Endocrinology and Infertility, University of Toronto, Toronto, ON, Canada
| | - Shadab A Rahman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States
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19
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Kazemi R, Alighanbari N, Zamanian Z. The effects of screen light filtering software on cognitive performance and sleep among night workers. Health Promot Perspect 2019; 9:233-240. [PMID: 31508344 PMCID: PMC6717920 DOI: 10.15171/hpp.2019.32] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/26/2019] [Indexed: 12/02/2022] Open
Abstract
Background: Previous studies have reported impaired performance, sleepiness and sleep deprivation among night workers. The purpose of this study was to investigate the effect of color screen Light Filtering software on cognitive performance, alertness and sleep quality among night shift operators of a medical emergency operations center. Methods: This field trial interventional study was carried out among 30 nightshift operators of shiraz emergency control center. The baseline assessments were carried out under the existing computer screen light conditions in the week preceding the installation of f.lux software. The same measurements were repeated again 4 weeks after installing the software. The cognitive performance of the participants was measured using continuous performance test (CPT) and n-back, while their sleep quality was assessed through Pietersburg Sleep Quality Index (PSQI). Further, to assess their subjective and objective alertness, Stanford sleepiness index and go/nogo test were used, respectively. Results: The results of this study showed that Screen Light Filtering software significantly increased subjective (P<0.001) and objective alertness (P<0.05). Additionally, the performance of the working memory (P=0.008) and sleep quality (P=0.008) improved significantly after the intervention. Conclusion: The results revealed that using Screen Light Filtering software is an effective and low-cost method to improve sleep quality and cognitive performance since it filters the short wavelength part of the spectrum and helps body adaptation.
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Affiliation(s)
- Reza Kazemi
- Ergonomics Department, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Negar Alighanbari
- School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Zamanian
- Ergonomics Department, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
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20
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LOWDEN A, ÖZTÜRK G, REYNOLDS A, BJORVATN B. Working Time Society consensus statements: Evidence based interventions using light to improve circadian adaptation to working hours. INDUSTRIAL HEALTH 2019; 57:213-227. [PMID: 30700675 PMCID: PMC6449639 DOI: 10.2486/indhealth.sw-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Interventions and strategies to improve health through the management of circadian (re) adaptation have been explored in the field, and in both human and animal laboratory manipulations of shiftwork. As part of an initiative by the Working Time Society (WTS) and International Committee on Occupational Health (ICOH), this review summarises the literature on the management of circadian (re) adaption using bright light treatment. Recommendations to maximise circadian adaptation are summarised for practitioners based on a variety of shiftwork schedules. In slowly rotating night shift schedules bright light appears most suitable when used in connection with the first three night shifts. These interventions are improved when combined with orange glasses (to block blue-green light exposure) for the commute home. Non-shifting strategies involve a lower dosage of light at night and promoting natural daylight exposure during the day (also recommended for day shifts) in acordance with the phase and amplitude response curves to light in humans.
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Affiliation(s)
- Arne LOWDEN
- Stress Research Institute, Stockholm University, Sweden
- *To whom correspondence should be addressed. E-mail:
| | - Gülcin ÖZTÜRK
- Stress Research Institute, Stockholm University, Sweden
| | | | - Bjørn BJORVATN
- Department of Global Public Health and Primary Care,
University of Bergen, Norway
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21
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Abstract
Light, through its non-imaging forming effects, plays a dominant role on a myriad of physiological functions, including the human sleep–wake cycle. The non-image forming effects of light heavily rely on specific properties such as intensity, duration, timing, pattern, and wavelengths. Here, we address how specific properties of light influence sleep and wakefulness in humans through acute effects, e.g., on alertness, and/or effects on the circadian timing system. Of critical relevance, we discuss how different characteristics of light exposure across the 24-h day can lead to changes in sleep–wake timing, sleep propensity, sleep architecture, and sleep and wake electroencephalogram (EEG) power spectra. Ultimately, knowledge on how light affects sleep and wakefulness can improve light settings at home and at the workplace to improve health and well-being and optimize treatments of chronobiological disorders.
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22
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Caldwell JA, Caldwell JL, Thompson LA, Lieberman HR. Fatigue and its management in the workplace. Neurosci Biobehav Rev 2019; 96:272-289. [DOI: 10.1016/j.neubiorev.2018.10.024] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/04/2018] [Accepted: 10/31/2018] [Indexed: 01/01/2023]
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23
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Brown GM, McIntyre RS, Rosenblat J, Hardeland R. Depressive disorders: Processes leading to neurogeneration and potential novel treatments. Prog Neuropsychopharmacol Biol Psychiatry 2018; 80:189-204. [PMID: 28433459 DOI: 10.1016/j.pnpbp.2017.04.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 04/01/2017] [Indexed: 12/18/2022]
Abstract
Mood disorders are wide spread with estimates that one in seven of the population are affected at some time in their life (Kessler et al., 2012). Many of those affected with severe depressive disorders have cognitive deficits which may progress to frank neurodegeneration. There are several peripheral markers shown by patients who have cognitive deficits that could represent causative factors and could potentially serve as guides to the prevention or even treatment of neurodegeneration. Circadian rhythm misalignment, immune dysfunction and oxidative stress are key pathologic processes implicated in neurodegeneration and cognitive dysfunction in depressive disorders. Novel treatments targeting these pathways may therefore potentially improve patient outcomes whereby the primary mechanism of action is outside of the monoaminergic system. Moreover, targeting immune dysfunction, oxidative stress and circadian rhythm misalignment (rather than primarily the monoaminergic system) may hold promise for truly disease modifying treatments that may prevent neurodegeneration rather than simply alleviating symptoms with no curative intent. Further research is required to more comprehensively understand the contributions of these pathways to the pathophysiology of depressive disorders to allow for disease modifying treatments to be discovered.
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Affiliation(s)
- Gregory M Brown
- Department of Psychiatry, University of Toronto, Centre for Addiction and Mental Health, 250 College St. Toronto, ON M5T 1R8, Canada.
| | - Roger S McIntyre
- Psychiatry and Pharmacology, University of Toronto, Mood Disorders Psychopharmacology Unit, University Health Network, 399 Bathurst Street, MP 9-325, Toronto, ON M5T 2S8, Canada.
| | - Joshua Rosenblat
- Resident of Psychiatry, Clinician Scientist Stream, University of Toronto, Mood Disorders Psychopharmacology Unit, University Health Network, 399 Bathurst Street, MP 9-325, Toronto, ON M5T 2S8, Canada
| | - Rüdiger Hardeland
- Johann Friedrich Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, Buergerstrasse 50, D-37073 Göttingen, Germany.
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24
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Souman JL, Tinga AM, te Pas SF, van Ee R, Vlaskamp BN. Acute alerting effects of light: A systematic literature review. Behav Brain Res 2018; 337:228-239. [DOI: 10.1016/j.bbr.2017.09.016] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/01/2017] [Accepted: 09/07/2017] [Indexed: 10/18/2022]
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25
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Green A, Cohen-Zion M, Haim A, Dagan Y. Comparing the response to acute and chronic exposure to short wavelength lighting emitted from computer screens. Chronobiol Int 2017; 35:90-100. [DOI: 10.1080/07420528.2017.1387555] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- A. Green
- The Israeli Center for Interdisciplinary Research in Chronobiology, University of Haifa, Haifa, Israel
- The Sleep and Fatigue Institute, Assuta Medical Center, Tel Aviv, Israel
| | - M. Cohen-Zion
- The Sleep and Fatigue Institute, Assuta Medical Center, Tel Aviv, Israel
- School of Behavioral Sciences, The Academic College of Tel Aviv Jaffa, Tel Aviv-Jaffa, Israel
| | - A. Haim
- The Israeli Center for Interdisciplinary Research in Chronobiology, University of Haifa, Haifa, Israel
| | - Y. Dagan
- The Israeli Center for Interdisciplinary Research in Chronobiology, University of Haifa, Haifa, Israel
- The Sleep and Fatigue Institute, Assuta Medical Center, Tel Aviv, Israel
- The Research Institute of Applied Chronobiology, The Academic College of Tel-Hai, Tel Hai, Israel
- The Department of Human Biology, University of Haifa, Haifa, Israel
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26
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Regente J, de Zeeuw J, Bes F, Nowozin C, Appelhoff S, Wahnschaffe A, Münch M, Kunz D. Can short-wavelength depleted bright light during single simulated night shifts prevent circadian phase shifts? APPLIED ERGONOMICS 2017; 61:22-30. [PMID: 28237017 DOI: 10.1016/j.apergo.2016.12.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 06/06/2023]
Abstract
In single night shifts, extending habitual wake episodes leads to sleep deprivation induced decrements of performance during the shift and re-adaptation effects the next day. We investigated whether short-wavelength depleted (=filtered) bright light (FBL) during a simulated night shift would counteract such effects. Twenty-four participants underwent a simulated night shift in dim light (DL) and in FBL. Reaction times, subjective sleepiness and salivary melatonin concentrations were assessed during both nights. Daytime sleep was recorded after both simulated night shifts. During FBL, we found no melatonin suppression compared to DL, but slightly faster reaction times in the second half of the night. Daytime sleep was not statistically different between both lighting conditions (n = 24) and there was no significant phase shift after FBL (n = 11). To conclude, our results showed positive effects from FBL during simulated single night shifts which need to be further tested with larger groups, in more applied studies and compared to standard lighting.
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Affiliation(s)
- J Regente
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, Immanuel Clinic Rüdersdorf, Medical School Brandenburg, Rüdersdorf near Berlin, Germany
| | - J de Zeeuw
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany
| | - F Bes
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany; Clinic for Sleep & Chronomedicine, St-Hedwig-Krankenhaus, D-10115 Berlin, Germany
| | - C Nowozin
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany; Clinic for Sleep & Chronomedicine, St-Hedwig-Krankenhaus, D-10115 Berlin, Germany
| | - S Appelhoff
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany
| | - A Wahnschaffe
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany; Clinic for Sleep & Chronomedicine, St-Hedwig-Krankenhaus, D-10115 Berlin, Germany
| | - M Münch
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany; Clinic for Sleep & Chronomedicine, St-Hedwig-Krankenhaus, D-10115 Berlin, Germany.
| | - D Kunz
- Charité University Medicine, Institute of Physiology, Sleep Research & Clinical Chronobiology, Berlin, Germany; Clinic for Sleep & Chronomedicine, St-Hedwig-Krankenhaus, D-10115 Berlin, Germany
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27
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The effects of spectral tuning of evening ambient light on melatonin suppression, alertness and sleep. Physiol Behav 2017; 177:221-229. [PMID: 28472667 DOI: 10.1016/j.physbeh.2017.05.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/15/2017] [Accepted: 05/01/2017] [Indexed: 11/22/2022]
Abstract
We compared the effects of bedroom-intensity light from a standard fluorescent and a blue- (i.e., short-wavelength) depleted LED source on melatonin suppression, alertness, and sleep. Sixteen healthy participants (8 females) completed a 4-day inpatient study. Participants were exposed to blue-depleted circadian-sensitive (C-LED) light and a standard fluorescent light (FL, 4100K) of equal illuminance (50lx) for 8h prior to a fixed bedtime on two separate days in a within-subject, randomized, cross-over design. Each light exposure day was preceded by a dim light (<3lx) control at the same time 24h earlier. Compared to the FL condition, control-adjusted melatonin suppression was significantly reduced. Although subjective sleepiness was not different between the two light conditions, auditory reaction times were significantly slower under C-LED conditions compared to FL 30min prior to bedtime. EEG-based correlates of alertness corroborated the reduced alertness under C-LED conditions as shown by significantly increased EEG spectral power in the delta-theta (0.5-8.0Hz) bands under C-LED as compared to FL exposure. There was no significant difference in total sleep time (TST), sleep efficiency (SE%), and slow-wave activity (SWA) between the two conditions. Unlike melatonin suppression and alertness, a significant order effect was observed on all three sleep variables, however. Individuals who received C-LED first and then FL had increased TST, SE% and SWA averaged across both nights compared to individuals who received FL first and then C-LED. These data show that the spectral characteristics of light can be fine-tuned to attenuate non-visual responses to light in humans.
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Canazei M, Pohl W, Bliem HR, Weiss EM. Acute effects of different light spectra on simulated night-shift work without circadian alignment. Chronobiol Int 2016; 34:303-317. [PMID: 27579732 DOI: 10.1080/07420528.2016.1222414] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Short-wavelength and short-wavelength-enhanced light have a strong impact on night-time working performance, subjective feelings of alertness and circadian physiology. In the present study, we investigated acute effects of white light sources with varied reduced portions of short wavelengths on cognitive and visual performance, mood and cardiac output.Thirty-one healthy subjects were investigated in a balanced cross-over design under three light spectra in a simulated night-shift paradigm without circadian adaptation.Exposure to the light spectrum with the largest attenuation of short wavelengths reduced heart rate and increased vagal cardiac parameters during the night compared to the other two light spectra without deleterious effects on sustained attention, working memory and subjective alertness. In addition, colour discrimination capability was significantly decreased under this light source.To our knowledge, the present study for the first time demonstrates that polychromatic white light with reduced short wavelengths, fulfilling current lighting standards for indoor illumination, may have a positive impact on cardiac physiology of night-shift workers without detrimental consequences for cognitive performance and alertness.
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Affiliation(s)
- Markus Canazei
- a Research Department , Bartenbach GmbH , Aldrans , Austria.,b Department of Psychology , University of Innsbruck , Innsbruck , Austria
| | - Wilfried Pohl
- a Research Department , Bartenbach GmbH , Aldrans , Austria
| | - Harald R Bliem
- b Department of Psychology , University of Innsbruck , Innsbruck , Austria
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Slanger TE, Gross JV, Pinger A, Morfeld P, Bellinger M, Duhme A, Reichardt Ortega RA, Costa G, Driscoll TR, Foster RG, Fritschi L, Sallinen M, Liira J, Erren TC. Person-directed, non-pharmacological interventions for sleepiness at work and sleep disturbances caused by shift work. Cochrane Database Syst Rev 2016; 2016:CD010641. [PMID: 27549931 PMCID: PMC8406755 DOI: 10.1002/14651858.cd010641.pub2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Shift work is often associated with sleepiness and sleep disorders. Person-directed, non-pharmacological interventions may positively influence the impact of shift work on sleep, thereby improving workers' well-being, safety, and health. OBJECTIVES To assess the effects of person-directed, non-pharmacological interventions for reducing sleepiness at work and improving the length and quality of sleep between shifts for shift workers. SEARCH METHODS We searched CENTRAL, MEDLINE Ovid, Embase, Web of Knowledge, ProQuest, PsycINFO, OpenGrey, and OSH-UPDATE from inception to August 2015. We also screened reference lists and conference proceedings and searched the World Health Organization (WHO) Trial register. We contacted experts to obtain unpublished data. SELECTION CRITERIA Randomised controlled trials (RCTs) (including cross-over designs) that investigated the effect of any person-directed, non-pharmacological intervention on sleepiness on-shift or sleep length and sleep quality off-shift in shift workers who also work nights. DATA COLLECTION AND ANALYSIS At least two authors screened titles and abstracts for relevant studies, extracted data, and assessed risk of bias. We contacted authors to obtain missing information. We conducted meta-analyses when pooling of studies was possible. MAIN RESULTS We included 17 relevant trials (with 556 review-relevant participants) which we categorised into three types of interventions: (1) various exposures to bright light (n = 10); (2) various opportunities for napping (n = 4); and (3) other interventions, such as physical exercise or sleep education (n = 3). In most instances, the studies were too heterogeneous to pool. Most of the comparisons yielded low to very low quality evidence. Only one comparison provided moderate quality evidence. Overall, the included studies' results were inconclusive. We present the results regarding sleepiness below. Bright light Combining two comparable studies (with 184 participants altogether) that investigated the effect of bright light during the night on sleepiness during a shift, revealed a mean reduction 0.83 score points of sleepiness (measured via the Stanford Sleepiness Scale (SSS) (95% confidence interval (CI) -1.3 to -0.36, very low quality evidence). Another trial did not find a significant difference in overall sleepiness on another sleepiness scale (16 participants, low quality evidence).Bright light during the night plus sunglasses at dawn did not significantly influence sleepiness compared to normal light (1 study, 17 participants, assessment via reaction time, very low quality evidence).Bright light during the day shift did not significantly reduce sleepiness during the day compared to normal light (1 trial, 61 participants, subjective assessment, low quality evidence) or compared to normal light plus placebo capsule (1 trial, 12 participants, assessment via reaction time, very low quality evidence). Napping during the night shiftA meta-analysis on a single nap opportunity and the effect on the mean reaction time as a surrogate for sleepiness, resulted in a 11.87 ms reduction (95% CI 31.94 to -8.2, very low quality evidence). Two other studies also reported statistically non-significant decreases in reaction time (1 study seven participants; 1 study 49 participants, very low quality evidence).A two-nap opportunity resulted in a statistically non-significant increase of sleepiness (subjective assessment) in one study (mean difference (MD) 2.32, 95% CI -24.74 to 29.38, 1 study, 15 participants, low quality evidence). Other interventionsPhysical exercise and sleep education interventions showed promise, but sufficient data to draw conclusions are lacking. AUTHORS' CONCLUSIONS Given the methodological diversity of the included studies, in terms of interventions, settings, and assessment tools, their limited reporting and the very low to low quality of the evidence they present, it is not possible to determine whether shift workers' sleepiness can be reduced or if their sleep length or quality can be improved with these interventions.We need better and adequately powered RCTs of the effect of bright light, and naps, either on their own or together and other non-pharmacological interventions that also consider shift workers' chronobiology on the investigated sleep parameters.
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Affiliation(s)
- Tracy E Slanger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - J. Valérie Gross
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Andreas Pinger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Peter Morfeld
- Evonik Technology & Infrastructure GmbHInstitute for Occupational Epidemiology and Risk Assessment (IERA)Rellinghauser Str. 1‐11EssenGermany45128
| | - Miriam Bellinger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Anna‐Lena Duhme
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Rosalinde Amancay Reichardt Ortega
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Giovanni Costa
- University of MilanDepartment of Clinical Sciences and Community HealthVia S. Barnaba 8MilanItaly20122
| | - Tim R Driscoll
- The University of SydneySchool of Public HealthEdward Ford Building (A27)SydneyNew South WalesAustralia2006
| | - Russell G Foster
- University of OxfordNuffield Department of Clinical Neurosciences; Circadian and Visual NeuroscienceLevel 6, West Wing, The John Radcliffe HospitalHeadley WayOxfordUKOX3 9DU
| | - Lin Fritschi
- Curtin UniversitySchool of Public Health35 Stirling HighwayPerthWest AustraliaAustralia6152
| | - Mikael Sallinen
- Finnish Institute of Occupational HealthCentre of Expertise for the Development of Work and Organizations / Working Hours, Alertness, and Professional Traffic teamTopeliuksenkatu 41 a AHelsinkiFinlandFI‐00250
| | - Juha Liira
- Finnish Institute of Occupational HealthResearch and Development in Occupational Health ServicesTopeliuksenkatu 41 a AHelsinkiFinlandFI‐00250
| | - Thomas C Erren
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
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Affiliation(s)
- Tracy A. Bedrosian
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, California 92037
| | - Laura K. Fonken
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309
| | - Randy J. Nelson
- Department of Neuroscience and Behavioral Neuroendocrinology Group, The Ohio State University, Columbus, Ohio 43210;
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Investigating the contribution of short wavelengths in the alerting effect of bright light. Physiol Behav 2015; 151:81-7. [DOI: 10.1016/j.physbeh.2015.06.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 06/17/2015] [Accepted: 06/20/2015] [Indexed: 11/22/2022]
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Smolensky MH, Sackett-Lundeen LL, Portaluppi F. Nocturnal light pollution and underexposure to daytime sunlight: Complementary mechanisms of circadian disruption and related diseases. Chronobiol Int 2015; 32:1029-48. [PMID: 26374931 DOI: 10.3109/07420528.2015.1072002] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Routine exposure to artificial light at night (ALAN) in work, home, and community settings is linked with increased risk of breast and prostate cancer (BC, PC) in normally sighted women and men, the hypothesized biological rhythm mechanisms being frequent nocturnal melatonin synthesis suppression, circadian time structure (CTS) desynchronization, and sleep/wake cycle disruption with sleep deprivation. ALAN-induced perturbation of the CTS melatonin synchronizer signal is communicated maternally at the very onset of life and after birth via breast or artificial formula feedings. Nighttime use of personal computers, mobile phones, electronic tablets, televisions, and the like--now epidemic in adolescents and adults and highly prevalent in pre-school and school-aged children--is a new source of ALAN. However, ALAN exposure occurs concomitantly with almost complete absence of daytime sunlight, whose blue-violet (446-484 nm λ) spectrum synchronizes the CTS and whose UV-B (290-315 nm λ) spectrum stimulates vitamin D synthesis. Under natural conditions and clear skies, day/night and annual cycles of UV-B irradiation drive corresponding periodicities in vitamin D synthesis and numerous bioprocesses regulated by active metabolites augment and strengthen the biological time structure. Vitamin D insufficiency and deficiency are widespread in children and adults in developed and developing countries as a consequence of inadequate sunlight exposure. Past epidemiologic studies have focused either on exposure to too little daytime UV-B or too much ALAN, respectively, on vitamin D deficiency/insufficiency or melatonin suppression in relation to risk of cancer and other, e.g., psychiatric, hypertensive, cardiac, and vascular, so-called, diseases of civilization. The observed elevated incidence of medical conditions the two are alleged to influence through many complementary bioprocesses of cells, tissues, and organs led us to examine effects of the totality of the artificial light environment in which humans reside today. Never have chronobiologic or epidemiologic investigations comprehensively researched the potentially deleterious consequences of the combination of suppressed vitamin D plus melatonin synthesis due to life in today's man-made artificial light environment, which in our opinion is long overdue.
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Affiliation(s)
- Michael H Smolensky
- a Department of Biomedical Engineering , Cockrell School of Engineering, The University of Texas at Austin , Austin , TX , USA
| | - Linda L Sackett-Lundeen
- b American Association for Clinical Chronobiology and Chronotherapeutics , Roseville , MN , USA , and
| | - Francesco Portaluppi
- c Hypertension Center, S. Anna University Hospital, University of Ferrara , Ferrara , Italy
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Krishnan HC, Lyons LC. Synchrony and desynchrony in circadian clocks: impacts on learning and memory. ACTA ACUST UNITED AC 2015; 22:426-37. [PMID: 26286653 PMCID: PMC4561405 DOI: 10.1101/lm.038877.115] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/29/2015] [Indexed: 12/11/2022]
Abstract
Circadian clocks evolved under conditions of environmental variation, primarily alternating light dark cycles, to enable organisms to anticipate daily environmental events and coordinate metabolic, physiological, and behavioral activities. However, modern lifestyle and advances in technology have increased the percentage of individuals working in phases misaligned with natural circadian activity rhythms. Endogenous circadian oscillators modulate alertness, the acquisition of learning, memory formation, and the recall of memory with examples of circadian modulation of memory observed across phyla from invertebrates to humans. Cognitive performance and memory are significantly diminished when occurring out of phase with natural circadian rhythms. Disruptions in circadian regulation can lead to impairment in the formation of memories and manifestation of other cognitive deficits. This review explores the types of interactions through which the circadian clock modulates cognition, highlights recent progress in identifying mechanistic interactions between the circadian system and the processes involved in memory formation, and outlines methods used to remediate circadian perturbations and reinforce circadian adaptation.
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Affiliation(s)
- Harini C Krishnan
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, Florida 32306, USA
| | - Lisa C Lyons
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, Florida 32306, USA
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Bonmati-Carrion MA, Arguelles-Prieto R, Martinez-Madrid MJ, Reiter R, Hardeland R, Rol MA, Madrid JA. Protecting the melatonin rhythm through circadian healthy light exposure. Int J Mol Sci 2014; 15:23448-500. [PMID: 25526564 PMCID: PMC4284776 DOI: 10.3390/ijms151223448] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 11/02/2014] [Accepted: 11/09/2014] [Indexed: 12/14/2022] Open
Abstract
Currently, in developed countries, nights are excessively illuminated (light at night), whereas daytime is mainly spent indoors, and thus people are exposed to much lower light intensities than under natural conditions. In spite of the positive impact of artificial light, we pay a price for the easy access to light during the night: disorganization of our circadian system or chronodisruption (CD), including perturbations in melatonin rhythm. Epidemiological studies show that CD is associated with an increased incidence of diabetes, obesity, heart disease, cognitive and affective impairment, premature aging and some types of cancer. Knowledge of retinal photoreceptors and the discovery of melanopsin in some ganglion cells demonstrate that light intensity, timing and spectrum must be considered to keep the biological clock properly entrained. Importantly, not all wavelengths of light are equally chronodisrupting. Blue light, which is particularly beneficial during the daytime, seems to be more disruptive at night, and induces the strongest melatonin inhibition. Nocturnal blue light exposure is currently increasing, due to the proliferation of energy-efficient lighting (LEDs) and electronic devices. Thus, the development of lighting systems that preserve the melatonin rhythm could reduce the health risks induced by chronodisruption. This review addresses the state of the art regarding the crosstalk between light and the circadian system.
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Affiliation(s)
| | | | | | - Russel Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA.
| | - Ruediger Hardeland
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen 37073, Germany.
| | - Maria Angeles Rol
- Department of Physiology, Faculty of Biology, University of Murcia, Murcia 30100, Spain.
| | - Juan Antonio Madrid
- Department of Physiology, Faculty of Biology, University of Murcia, Murcia 30100, Spain.
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Spectral modulation of light wavelengths using optical filters: effect on melatonin secretion. Fertil Steril 2014; 102:336-8. [DOI: 10.1016/j.fertnstert.2014.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/04/2014] [Accepted: 06/04/2014] [Indexed: 11/22/2022]
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