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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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Shriane AE, Rigney G, Ferguson SA, Bin YS, Vincent GE. Healthy sleep practices for shift workers: consensus sleep hygiene guidelines using a Delphi methodology. Sleep 2023; 46:zsad182. [PMID: 37429599 PMCID: PMC10710992 DOI: 10.1093/sleep/zsad182] [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: 11/27/2022] [Revised: 06/19/2023] [Indexed: 07/12/2023] Open
Abstract
STUDY OBJECTIVES The unique requirements of shift work, such as sleeping and working at variable times, mean that current sleep hygiene guidelines may be inappropriate for shift workers. Current guidelines may also contradict fatigue management advice (e.g. advising against daytime napping). The present study utilized a Delphi methodology to determine expert opinion regarding the applicability of current guidelines for shift workers, the appropriateness of the term "sleep hygiene," and develop tailored guidelines for shift workers. METHODS The research team reviewed current guidelines and existing evidence to draft tailored guidelines. Seventeen individual guidelines, covering sleep scheduling, napping, sleep environment, bedtime routine, substances, light exposure, diet, and exercise were drafted. Experts from sleep, shift work, and occupational health fields (n = 155) were invited to review the draft guidelines using a Delphi methodology. In each round, experts voted on individual guidelines, with 70% agreement considered consensus. Where consensus was not reached, written feedback from experts was discussed and incorporated into subsequent iterations. RESULTS Of the experts invited, 68 (44%) agreed to participate, with 55 (35%) completing the third (final) round. Most experts (84%) agreed that tailored guidelines were required for shift workers. Consensus was reached on all guidelines after three rounds. One additional guideline (sleep inertia) and an introductory statement were developed, resulting in a final set of 18 individual guidelines, termed "healthy sleep practices for shift workers." CONCLUSIONS This is the first study to develop tailored sleep hygiene guidelines for shift workers. Future research should investigate the acceptability and effectiveness of these guidelines amongst shift workers.
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Affiliation(s)
- Alexandra E Shriane
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Adelaide, SA, Australia
| | - Gabrielle Rigney
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Adelaide, SA, Australia
| | - Sally A Ferguson
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Adelaide, SA, Australia
| | - Yu Sun Bin
- Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
- Northern Clinical School, Sydney Medical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Grace E Vincent
- Appleton Institute, School of Health, Medical and Applied Sciences, Central Queensland University, Adelaide, SA, Australia
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Bessman SC, Harrison EM, Easterling AP, Snider MN, Preilipper SMM, Glickman GL. Hybrid effectiveness-implementation study of two novel spectrally engineered lighting interventions for shiftworkers on a high-security watchfloor. SLEEP ADVANCES : A JOURNAL OF THE SLEEP RESEARCH SOCIETY 2023; 4:zpad051. [PMID: 38084298 PMCID: PMC10710545 DOI: 10.1093/sleepadvances/zpad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/13/2023] [Indexed: 06/26/2024]
Abstract
Shiftwork leads to myriad negative health and safety outcomes. Lighting countermeasures can benefit shiftworkers via physiological effects of light (e.g. alerting, circadian adjustment), and short-wavelength light is the most potent for eliciting those responses; however, limited work indicates it may not be required for alerting. We developed similar-appearing light boxes (correlated color temperature: 3000-3375 K; photopic illuminance: 260-296 lux), enriched (SW+, melanopic EDI: 294 lux) or attenuated (SW-, melanopic EDI: 103 lux) in short-wavelength energy, and implemented them on a high-security watchfloor. Efficacy and feasibility of these two novel lighting interventions were assessed in personnel working 12-hour night shifts (n = 47) in this within-participants, crossover study. For each intervention condition, light boxes were arranged across the front of the watchfloor and illuminated the entire shift; blue-blocking glasses were worn post-shift and before sleep; and sleep masks were used while sleeping. Comparisons between baseline and intervention conditions included alertness, sleep, mood, quality of life (QOL), and implementation measures. On-shift alertness (Karolinska Sleepiness Scale) increased in SW- compared to baseline, while changes in SW+ were more limited. Under SW+, both mood and sleep improved. Psychomotor vigilance task performance did not vary by condition; however, perceived performance and QOL were higher, and reported caffeine consumption and sleep onset latency were lower, under SW-. For both interventions, satisfaction and comfort were high, and fewer symptoms and negative feelings were reported. The addition of spectrally engineered lights to this unique work environment improved sleep, alertness, and mood without compromising visual comfort and satisfaction. This paper is part of the Sleep and Circadian Rhythms: Management of Fatigue in Occupational Settings Collection.
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Affiliation(s)
- Sara C Bessman
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Elizabeth M Harrison
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Alexandra P Easterling
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Michelle N Snider
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Sebastian M M Preilipper
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, USA
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Gena L Glickman
- Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, USA
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He M, Liu K, Cao J, Chen Q. An update on the role and potential mechanisms of clock genes regulating spermatogenesis: A systematic review of human and animal experimental studies. Rev Endocr Metab Disord 2023; 24:585-610. [PMID: 36792803 DOI: 10.1007/s11154-022-09783-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/25/2022] [Indexed: 02/17/2023]
Abstract
Circadian clocks can be traced in nearly all life kingdoms, with the male reproductive system no exception. However, our understanding of the circadian clock in spermatogenesis seems to fall behind other scenarios. The present review aims to summarize the current knowledge about the role and especially the potential mechanisms of clock genes in spermatogenesis regulation. Accumulating studies have revealed rhythmic oscillation in semen parameters and some physiological events of spermatogenesis. Disturbing the clock gene expression by genetic mutations or environmental changes will also notably damage spermatogenesis. On the other hand, the mechanisms of spermatogenetic regulation by clock genes remain largely unclear. Some recent studies, although not revealing the entire mechanisms, indeed attempted to shed light on this issue. Emerging clues hinted that gonadal hormones, retinoic acid signaling, homologous recombination, and the chromatoid body might be involved in the regulation of spermatogenesis by clock genes. Then we highlight the challenges and the promising directions for future studies so as to stimulate attention to this critical field which has not gained adequate concern.
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Affiliation(s)
- Mengchao He
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Kun Liu
- Center for Disease Control and Prevention of Southern Theatre Command, Guangzhou, 510630, China
| | - Jia Cao
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
| | - Qing Chen
- Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Institute of Toxicology, College of Preventive Medicine, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
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Hébert M, Lavigne AA, Auclair J, Martin JS, Francis K, Gagnon JD, Dubois MA, Laberge L. A Blue-Enriched Light Intervention Counteracts the Alertness Decrement Among Mine Workers on Extended 12-Hour Night Shift Periods. J Occup Environ Med 2023; 65:584-589. [PMID: 36962091 DOI: 10.1097/jom.0000000000002849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
OBJECTIVE The aim of the study is to assess whether a blue-enriched light intervention improves nocturnal alertness and daytime sleep of night workers. METHODS Thirteen miners performing 12-hour night shifts for 12 consecutive nights were exposed to a baseline and a blue-enriched light condition. All subjects wore an actigraph and completed a Psychomotor Vigilance Task at the beginning and at the end of each shift. Data were analyzed with linear mixed models. RESULTS In the blue-enriched light condition, the daily increase in median reaction time (RT), mean RT, slowest 10% of RT, and fastest 10% of RT was lower than that observed in the baseline condition between day 1 and 12 ( P ≤ 0.05). CONCLUSIONS The addition of blue-enriched light during a long period of extended night shifts counteracts most of the daily decline in nocturnal alertness observed in the standard lighting condition, irrespectively of sleep duration and sleep efficiency.
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Affiliation(s)
- Marc Hébert
- From the Centre de recherche CERVO, Centre Intégré Universitaire de Santé et des Services Sociaux de la Capitale Nationale, Québec, Canada (M.H., A.-A.L., J.-S.M., K.F., J.D.G., M.-A.D.); Département d'Ophtalmologie et d'Oto-Rhino-Laryngologie-Chirurgie Cervico-Faciale, Faculté de Médecine, Université Laval, Québec, Canada (M.H., L.L.); ÉCOBES-Recherche et transfert, Cégep de Jonquière, Saguenay, Canada (J.A., L.L.); and Département de la santé, Université du Québec à Chicoutimi, Chicoutimi, Canada (L.L.)
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Cyr M, Artenie DZ, Al Bikaii A, Borsook D, Olson JA. The effect of evening light on circadian-related outcomes: A systematic review. Sleep Med Rev 2022; 64:101660. [PMID: 35753149 DOI: 10.1016/j.smrv.2022.101660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/26/2022] [Accepted: 05/31/2022] [Indexed: 11/26/2022]
Abstract
Bright light exposure at night can help workers adapt to their shift schedules, but there has been relatively little research on evening light. We conducted a systematic review of studies that manipulated light exposure in the evening (broadly defined as 16:00-22:00) before real or simulated night shifts. Across the five eligible studies, evening light produced phase delays in melatonin, body temperature, and sleep propensity; it also improved sleep quality, sleep duration, memory, and work performance. There were mixed effects for mood, no changes in sleepiness, and no negative effects. The confidence in these results ranged from moderate for physiological markers of circadian phase delays to very low for mood. Future studies should compare the relative effectiveness and safety of evening versus night-time light exposure. Overall, the benefits of evening light for shift workers are tentative yet promising.
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Affiliation(s)
- Mariève Cyr
- Faculty of Medicine and Health Sciences, McGill University, Montréal, QC, Canada
| | - Despina Z Artenie
- Department of Psychology, Université du Québec à Montréal, QC, Canada
| | | | - David Borsook
- Departments of Psychiatry and Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Jay A Olson
- Department of Psychology, Harvard University, Cambridge, MA, USA.
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Mason BJ, Tubbs AS, Fernandez FX, Grandner MA. Spectrophotometric properties of commercially available blue blockers across multiple lighting conditions. Chronobiol Int 2022; 39:653-664. [PMID: 34983271 PMCID: PMC9106867 DOI: 10.1080/07420528.2021.2021229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Lenses that filter short-wavelength ("blue") light are commercially marketed to improve sleep and circadian health. Despite their widespread use, minimal data are available regarding their comparative efficacy in curtailing blue light exposure while maintaining visibility. Fifty commercial lenses were evaluated using five light sources: a blue LED array, a computer tablet display, an incandescent lamp, a fluorescent overhead luminaire, and sunlight. Absolute irradiance was measured at baseline and for each lens across the visual spectrum (380-780 nm), which allowed calculation of percent transmission. Transmission specificity was also calculated to determine whether light transmission was predominantly circadian-proficient (455-560 nm) or non-proficient (380-454 nm and 561-780 nm). Lenses were grouped by tint and metrics were compared between groups. Red-tinted lenses exhibited the lowest transmission of circadian-proficient light, while reflective blue lenses had the highest transmission. Orange-tinted lenses transmitted similar circadian-proficient light as red-tinted lenses but transmitted more non-circadian-proficient light, resulting in higher transmission specificity. Orange-tinted lenses had the highest transmission specificity while limiting biologically active light exposure in ordinary lighting conditions. Glasses incorporating these lenses currently have the greatest potential to support circadian sleep-wake rhythms.
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Affiliation(s)
- Brooke J Mason
- Sleep and Health Research Program, Department of Psychiatry, University of Arizona College of Medicine - Tucson, Tucson, Arizona, USA
| | - Andrew S Tubbs
- Sleep and Health Research Program, Department of Psychiatry, University of Arizona College of Medicine - Tucson, Tucson, Arizona, USA
| | - Fabian-Xosé Fernandez
- Light Algorithms Laboratory, Department of Psychology, University of Arizona College of Science, Tucson, Arizona, USA
| | - Michael A Grandner
- Sleep and Health Research Program, Department of Psychiatry, University of Arizona College of Medicine - Tucson, Tucson, Arizona, USA
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8
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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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Martin JS, Laberge L, Sasseville A, Bérubé M, Alain S, Lavoie J, Houle J, Hébert M. Timely use of in-car dim blue light and blue blockers in the morning does not improve circadian adaptation of fast rotating shift workers. Chronobiol Int 2021; 38:705-719. [PMID: 33588653 DOI: 10.1080/07420528.2021.1872592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Circadian adaptation to night work usually does not occur in naturalistic conditions, largely due to exposure to low levels of light during the night and light in the morning on the way home. This leads to circadian misalignment, which has documented deleterious effects on sleep and functioning during waking hours. Chronic circadian misalignment is also being increasingly associated with long-term health comorbidities. As the circadian system is mostly sensitive to short wavelengths (i.e., blue light) and less sensitive to long wavelengths (i.e., red light), shaping light exposure in a "wavelength-wise" manner has been proposed to promote partial adaptation to night shifts, and, therefore, alleviate circadian rhythms disruption. This report presents results from two cross-over designed studies that aimed to investigate the effects of three different light conditions on circadian phase, sleepiness, and alertness of police patrol officers on a rotating shift schedule. The first study took place during summer (n = 15) and the second study (n = 25) during winter/early spring. In both studies, all participants went through three conditions composed of four consecutive night shifts: 1) in-car dim blue light exposure during the night shift and wearing of blue-blocking glasses (BBG) in the morning after 05:00 h; 2) in-car red light exposure during the night shift and wearing of BBG in the morning after 05:00 h; 3) a control condition with no intervention. To assess circadian phase position, salivary melatonin was collected hourly the night before and the night after each condition. Sleep was monitored by wrist actigraphy. Also, a 10-min Psychomotor Vigilance-Task was administered at the beginning and end of each night shift and the Karolinska Sleepiness Scale was completed every 2 h during each night shift. In the summer study, no difference was found in alertness and sleepiness between conditions. Participants though exhibited greater (≈3 h) phase delay after four consecutive night shifts in the control condition (in which morning light exposure was expected to prevent phase delay) than after the blue and red conditions (≈2 h) (in which wearing BBG were expected to promote phase delay). In the second study performed during the winter/early spring, a comparable ≈2 h phase delay was found in each of the three conditions, with no difference in alertness and sleepiness between conditions. In conclusion, participants in both studies exhibited modest phase delay across the four night shifts, even during the control conditions. Still, re-entrainment was not fast enough to produce partial circadian adaptation after four night shifts. A greater number of consecutive night shifts may be necessary to produce enough circadian alignment to elicit benefits on sleepiness and alertness in workers driving a motorized vehicle during night shifts. In-car dim blue light exposure combined with the wearing of BBG in the morning did not show the expected benefits on circadian adaptation, sleepiness, and alertness in our studies. Higher levels of light may be warranted when implementing light intervention in a motorized vehicle setting.
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Affiliation(s)
| | - Luc Laberge
- ÉCOBES - Recherche et Transfert, Cégep de Jonquière, Saguenay, Québec, Canada.,Département des Sciences de la Santé, Université du Québec à Chicoutimi, Saguenay, Québec, Canada.,Département d'ophtalmologie et ORL-chirurgie Cervico-faciale, Université Laval, Québec, Québec, Canada
| | | | - Marilie Bérubé
- CERVO Brain Research Centre, Université Laval, Québec, Québec, Canada
| | - Samuel Alain
- CERVO Brain Research Centre, Université Laval, Québec, Québec, Canada
| | - Joëlle Lavoie
- CERVO Brain Research Centre, Université Laval, Québec, Québec, Canada
| | - Jérôme Houle
- CERVO Brain Research Centre, Université Laval, Québec, Québec, Canada
| | - Marc Hébert
- CERVO Brain Research Centre, Université Laval, Québec, Québec, Canada.,Département d'ophtalmologie et ORL-chirurgie Cervico-faciale, Université Laval, Québec, Québec, Canada
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Crowther ME, Ferguson SA, Vincent GE, Reynolds AC. Non-Pharmacological Interventions to Improve Chronic Disease Risk Factors and Sleep in Shift Workers: A Systematic Review and Meta-Analysis. Clocks Sleep 2021; 3:132-178. [PMID: 33525534 PMCID: PMC7930959 DOI: 10.3390/clockssleep3010009] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Shift work is associated with adverse chronic health outcomes. Addressing chronic disease risk factors including biomedical risk factors, behavioural risk factors, as well as sleep and perceived health status, affords an opportunity to improve health outcomes in shift workers. The present study aimed to conduct a systematic review, qualitative synthesis, and meta-analysis of non-pharmacological interventions targeting chronic disease risk factors, including sleep, in shift workers. A total of 8465 records were retrieved; 65 publications were eligible for inclusion in qualitative analysis. Random-effects meta-analysis were conducted for eight eligible health outcomes, including a total of thirty-nine studies. Interventions resulted in increased objective sleep duration (Hedges' g = 0.73; CI: 0.36, 1.10, k = 16), improved objective sleep efficiency (Hedges' g = 0.48; CI: 0.20, 0.76, k = 10) and a small increase in both subjective sleep duration (Hedges' g = 0.11; CI: -0.04, 0.27, k = 19) and sleep quality (Hedges' g = 0.11; CI: -0.11, 0.33, k = 21). Interventions also improved perceived health status (Hedges' g = 0.20; CI: -0.05, 0.46, k = 8), decreased systolic (Hedges' g = 0.26; CI: -0.54, 0.02, k = 7) and diastolic (Hedges' g = 0.06; CI: -0.23, 0.36, k = 7) blood pressure, and reduced body mass index (Hedges' g = -0.04; CI: -0.37, 0.29, k = 9). The current study suggests interventions may improve chronic disease risk factors and sleep in shift workers; however, this could only be objectively assessed for a limited number of risk factor endpoints. Future interventions could explore the impact of non-pharmacological interventions on a broader range of chronic disease risk factors to better characterise targets for improved health outcomes in shift workers.
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Affiliation(s)
- Meagan E Crowther
- The Appleton Institute, CQUniversity, 44 Greenhill Road, Wayville, SA 5034, Australia; (S.AF.); (G.EV.)
- School of Health, Medical and Applied Sciences, CQUniversity Australia, Adelaide Campus, Wayville, SA 5034, Australia
| | - Sally A Ferguson
- The Appleton Institute, CQUniversity, 44 Greenhill Road, Wayville, SA 5034, Australia; (S.AF.); (G.EV.)
- School of Health, Medical and Applied Sciences, CQUniversity Australia, Adelaide Campus, Wayville, SA 5034, Australia
| | - Grace E Vincent
- The Appleton Institute, CQUniversity, 44 Greenhill Road, Wayville, SA 5034, Australia; (S.AF.); (G.EV.)
- School of Health, Medical and Applied Sciences, CQUniversity Australia, Adelaide Campus, Wayville, SA 5034, Australia
| | - Amy C Reynolds
- Flinders Health and Medical Research Institute (Sleep Health)/Adelaide Institute for Sleep Health (AISH): A Flinders Centre of Research Excellence, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
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11
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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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12
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Harrison EM, Schmied EA, Easterling AP, Yablonsky AM, Glickman GL. A Hybrid Effectiveness-Implementation Study of a Multi-Component Lighting Intervention for Hospital Shift Workers. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E9141. [PMID: 33297521 PMCID: PMC7730086 DOI: 10.3390/ijerph17239141] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/12/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022]
Abstract
Simple lighting solutions may mitigate the harmful effects of shiftwork. This hybrid effectiveness-implementation study evaluated a multi-component lighting intervention in hospital nurses that included 6500 K architectural lighting in the nurses' station plus optional behavioral components (a lightbox, blueblocker glasses, eyemasks) with instruction about appropriately timed usage. Selective improvements from baseline were observed in on-shift performance, sleep quality, and caffeine consumption in day workers (all p < 0.05); off-shift sleepiness scores improved for night workers (p < 0.05). Further, self-reported measures of quality of life improved for both groups (p < 0.05). Preliminary implementation data from interviews and questionnaires suggest perceived benefits and high acceptability of the intervention.
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Affiliation(s)
- Elizabeth M. Harrison
- Center for Circadian Biology, University of California San Diego, La Jolla, CA 92093, USA; (A.P.E.); (G.L.G.)
- Leidos, Inc., San Diego, CA 92121, USA
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA 92016, USA;
| | - Emily A. Schmied
- School of Public Health, San Diego State University, San Diego, CA 92182, USA;
| | - Alexandra P. Easterling
- Center for Circadian Biology, University of California San Diego, La Jolla, CA 92093, USA; (A.P.E.); (G.L.G.)
- Leidos, Inc., San Diego, CA 92121, USA
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA 92016, USA;
| | - Abigail M. Yablonsky
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA 92016, USA;
- Naval Medical Center, San Diego, CA 92134, USA
| | - Gena L. Glickman
- Center for Circadian Biology, University of California San Diego, La Jolla, CA 92093, USA; (A.P.E.); (G.L.G.)
- Departments of Psychiatry and Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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13
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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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14
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Touitou Y, Point S. Effects and mechanisms of action of light-emitting diodes on the human retina and internal clock. ENVIRONMENTAL RESEARCH 2020; 190:109942. [PMID: 32758719 DOI: 10.1016/j.envres.2020.109942] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/29/2020] [Accepted: 07/10/2020] [Indexed: 05/11/2023]
Abstract
White light-emitting diodes (LEDs) will likely become the most used lighting devices worldwide in the future because of their very low prices over the course of their long lifespans which can be up to several tens of thousands of hours. The expansion of LED use in both urban and domestic lighting has prompted questions regarding their possible health effects, because the light that they provide is potentially high in the harmful blue band (400-500 nm) of the visible light spectrum. Research on the potential effects of LEDs and their blue band on human health has followed three main directions: 1) examining their retinal phototoxicity; 2) examining disruption of the internal clock, i.e., an out-of-sync clock, in shift workers and night workers, including the accompanying health issues, most concerningly an increased relative risk of cancer; and 3) examining risky, inappropriate late-night use of smartphones and consoles among children and adolescents. Here, we document the recognized or potential health issues associated with LED lighting together with their underlying mechanisms of action. There is so far no evidence that LED lighting is deleterious to human retina under normal use. However, exposure to artificial light at night is a new source of pollution because it affects the circadian clock. Blue-rich light, including cold white LEDs, should be considered a new endocrine disruptor, because it affects estrogen secretion and has unhealthful consequences in women, as demonstrated to occur via a complex mechanism.
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Affiliation(s)
- Yvan Touitou
- Unité de Chronobiologie, Fondation A. de Rothschild, 75019, Paris, France.
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15
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Eo YJ, Kim S, Lee KN, Kim DH, Kim C, Lee SM, Do YR. WITHDRAWN: Development of a circadian illuminometer to measure the intra-daily non-visual circadian illuminance. Biosens Bioelectron 2020. [DOI: 10.1016/j.bios.2020.112688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Domagalik A, Oginska H, Beldzik E, Fafrowicz M, Pokrywka M, Chaniecki P, Rekas M, Marek T. Long-Term Reduction of Short-Wavelength Light Affects Sustained Attention and Visuospatial Working Memory With No Evidence for a Change in Circadian Rhythmicity. Front Neurosci 2020; 14:654. [PMID: 32719581 PMCID: PMC7348134 DOI: 10.3389/fnins.2020.00654] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 05/27/2020] [Indexed: 01/01/2023] Open
Abstract
The short wavelength, i.e., blue light, is crucial for non-image forming effects such as entrainment of the circadian system in humans. Moreover, many studies showed that blue light enhances alertness and performance in cognitive tasks. However, most scientific reports in this topic are based on experiments using short exposure to blue or blue-enriched light, and only a few focused on the effects of its reduced transmittance, especially in longer periods. The latter could potentially give insight into understanding if age-related sleep problems and cognitive decline are related to less amount of blue light reaching the retina, as the eyes' lenses yellow with age. In this study, we investigated the effects of prolonged blocking of blue light on cognitive functioning, in particular-sustained attention and visuospatial working memory, as well as on sleep, and melatonin and cortisol levels. A group of young, healthy participants was randomly allocated to either blue light blocking or control group. Depending on the group, participants wore amber contact lenses, reducing the transmittance of blue light by ∼90% or regular contact lenses for a period of 4 weeks. No changes were observed for measurements related to sleep and sleep-wake rhythm. Dim light melatonin onset, evening levels of melatonin, and morning cortisol answer did not show any significant alterations during blue light (BL) blockade. The significant effects were revealed both for sustained attention and visuospatial memory, i.e., the longer blocking the blue light lasted, the greater decrease in performance observed. Additionally, the follow-up session conducted ∼1 week after taking off the blue-blocking lenses revealed that in case of sustained attention, this detrimental effect of blocking BL is fully reversible. Our findings provide evidence that prolonged reduction of BL exposure directly affects human cognitive functioning regardless of circadian rhythmicity.
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Affiliation(s)
- Aleksandra Domagalik
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Halszka Oginska
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
| | - Ewa Beldzik
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
| | - Magdalena Fafrowicz
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
| | - Malgorzata Pokrywka
- Department of Clinical Biochemistry, Jagiellonian University Medical College, Kraków, Poland
| | | | - Marek Rekas
- Ophthalmology Department, Military Institute of Medicine, Warsaw, Poland
| | - Tadeusz Marek
- Brain Imaging Core Facility, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Cognitive Neuroscience and Neuroergonomics, Institute of Applied Psychology, Jagiellonian University, Kraków, Poland
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17
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Aarts MPJ, Hartmeyer SL, Morsink K, Kort HSM, de Kort YAW. Can Special Light Glasses Reduce Sleepiness and Improve Sleep of Nightshift Workers? A Placebo-Controlled Explorative Field Study. Clocks Sleep 2020; 2:225-245. [PMID: 33089202 PMCID: PMC7445845 DOI: 10.3390/clockssleep2020018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/21/2020] [Indexed: 12/22/2022] Open
Abstract
Nightshift workers go against the natural sleep-wake rhythm. Light can shift the circadian clock but can also induce acute alertness. This placebo-controlled exploratory field study examined the effectiveness of light glasses to improve alertness while reducing the sleep complaints of hospital nurses working nightshifts. In a crossover within-subjects design, 23 nurses participated, using treatment glasses and placebo glasses. Sleepiness and sleep parameters were measured. A linear mixed model analysis on sleepiness revealed no significant main effect of the light intervention. An interaction effect was found indicating that under the placebo condition, sleepiness was significantly higher on the first nightshift than on the last night, while under the treatment condition, sleepiness remained stable across nightshift sessions. Sleepiness during the commute home also showed a significant interaction effect, demonstrating that after the first nightshift, driver sleepiness was higher for placebo than for treatment. Subjective sleep quality showed a negative main effect of treatment vs. placebo, particularly after the first nightshift. In retrospect, both types of light glasses were self-rated as effective. The use of light glasses during the nightshift may help to reduce driver sleepiness during the commute home, which is relevant, as all participants drove home by car or (motor) bike.
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Affiliation(s)
- Mariëlle P J Aarts
- Department of the Built Environment, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; (K.M.); (H.S.M.K.)
| | - Steffen L Hartmeyer
- Department of Industrial Engineering and Innovation Sciences, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; (S.L.H.); (Y.A.W.d.K.)
| | - Kars Morsink
- Department of the Built Environment, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; (K.M.); (H.S.M.K.)
| | - Helianthe S M Kort
- Department of the Built Environment, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; (K.M.); (H.S.M.K.)
- Technology for Healthcare Innovations, Utrecht University of Applied Science, P.O. Box 12011, 3501 AA Utrecht, The Netherlands
| | - Yvonne A W de Kort
- Department of Industrial Engineering and Innovation Sciences, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; (S.L.H.); (Y.A.W.d.K.)
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18
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Šmotek M, Fárková E, Manková D, Kopřivová J. Evening and night exposure to screens of media devices and its association with subjectively perceived sleep: Should "light hygiene" be given more attention? Sleep Health 2020; 6:498-505. [PMID: 32197951 DOI: 10.1016/j.sleh.2019.11.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/18/2019] [Accepted: 11/22/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The aim of the study was to examine subjective sleep quality in a population of healthy volunteers and its association with evening and night light exposure to screens of media devices. METHODS A total of 693 participants (mean age 31.2±11.4 years, 159 men, and 538 women) completed an online questionnaire battery consisting of several sleep-related questionnaires: PSQI, FSS, MCTQ, MEQ, and added questions assessing the timing and character the evening and night exposure to electronical devices (TV, PC, tablets, and phones), and the use of various filters blocking short-wavelength light. RESULTS Statistical analyses show that longer cumulative exposure to screen light in the evening was associated with greater sleep inertia in the morning (P = .019, η2=0.141) and longer sleep latency on workdays P = .038, η2=0.135). Furthermore, exposure to screen light 1.5 h before sleep or during night awakenings was also associated with a decreased chance to wake up before alarm clock (P = .003, d=0.30), larger social jet lag (P < .001, d=0.15), more daytime dysfunction (P < .001, d=0.40), decreased subjective sleep quality (P = .024, d=0.16), and more fatigue (P < .001, d=0.52). A statistical trend for an increase in duration of sleep on weekdays (P = .058, d=0.23) was also found in participants using blue-light filters in the evening hours. DISCUSSION Our results are in line with other studies that converge to show the negative association of evening and night exposure to short-wavelength light on subjective and objective sleep parameters. Results suggest that light hygiene in general population should be given more attention not only in the context of clinical sleep medicine but also in the realm of public health.
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Affiliation(s)
- Michal Šmotek
- National Institute of Mental Health, Klecany, Czech Republic; Third Faculty of Medicine, Charles University, Prague, Czech Republic.
| | - Eva Fárková
- National Institute of Mental Health, Klecany, Czech Republic; Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Denisa Manková
- National Institute of Mental Health, Klecany, Czech Republic
| | - Jana Kopřivová
- National Institute of Mental Health, Klecany, Czech Republic; Third Faculty of Medicine, Charles University, Prague, Czech Republic
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19
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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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20
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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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21
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Lee S, Kakitsuba N, Katsuura T. Do green-blocking glasses enhance the nonvisual effects of white polychromatic light? J Physiol Anthropol 2018; 37:29. [PMID: 30563575 PMCID: PMC6299521 DOI: 10.1186/s40101-018-0189-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 12/04/2018] [Indexed: 12/03/2022] Open
Abstract
Background It is well known that light containing the blue component stimulates the intrinsically photosensitive retinal ganglion cells (ipRGCs) and plays a role in melatonin suppression and pupillary constriction. In our previous studies, we verified that simultaneous exposure to blue and green light resulted in less pupillary constriction than blue light exposure. Hence, we hypothesized that the nonvisual effects of polychromatic white light might be increased by blocking the green component. Therefore, we conducted an experiment using optical filters that blocked blue or green component and examined the nonvisual effects of these lights on pupillary constriction and electroencephalogram power spectra. Methods Ten healthy young males participated in this study. The participant sat on a chair with his eyes facing an integrating sphere. After 10 min of light adaptation, the participant’s left eye was exposed to white pulsed light (1000 lx; pulse width 2.5 ms) every 10 s with a blue-blocking glasses, a green-blocking glasses, or control glasses (no lens), and pupillary constriction was measured. Then, after rest for 10 min, the participant was exposed a continuous white light of 1000 lx with a blue- or green-blocking glasses or control glasses and electroencephalogram was measured. Results Pupillary constriction with the blue-blocking glasses was significantly less than that observed with the green-blocking glasses. Furthermore, pupillary constriction under the green-blocking glasses was significantly greater than that observed with the control glasses. Conclusions A reduction in the green component of light facilitated pupillary constriction. Thus, the effects of polychromatic white light containing blue and green components on ipRGCs are apparently increased by removing the green component.
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Affiliation(s)
- Soomin Lee
- Center for Environment, Health and Sciences, Chiba University, Kashiwa, Japan.
| | - Naoshi Kakitsuba
- Faculty of Science and Technology, Meijo University, Nagoya, Japan
| | - Tetso Katsuura
- Graduate School of Engineering, Chiba University, Chiba, Japan
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22
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Perry B, Herrington W, Goldsack JC, Grandinetti CA, Vasisht KP, Landray MJ, Bataille L, DiCicco RA, Bradley C, Narayan A, Papadopoulos EJ, Sheth N, Skodacek K, Stem K, Strong TV, Walton MK, Corneli A. Use of Mobile Devices to Measure Outcomes in Clinical Research, 2010-2016: A Systematic Literature Review. Digit Biomark 2018; 2:11-30. [PMID: 29938250 PMCID: PMC6008882 DOI: 10.1159/000486347] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 12/13/2017] [Indexed: 01/08/2023] Open
Abstract
Background The use of mobile devices in clinical research has advanced substantially in recent years due to the rapid pace of technology development. With an overall aim of informing the future use of mobile devices in interventional clinical research to measure primary outcomes, we conducted a systematic review of the use of and clinical outcomes measured by mobile devices (mobile outcomes) in observational and interventional clinical research. Method We conducted a PubMed search using a range of search terms to retrieve peer-reviewed articles on clinical research published between January 2010 and May 2016 in which mobile devices were used to measure study outcomes. We screened each publication for specific inclusion and exclusion criteria. We then identified and qualitatively summarized the use of mobile outcome assessments in clinical research, including the type and design of the study, therapeutic focus, type of mobile device(s) used, and specific mobile outcomes reported. Results The search retrieved 2,530 potential articles of interest. After screening, 88 publications remained. Twenty-five percent of the publications (n = 22) described mobile outcomes used in interventional research, and the rest (n = 66) described observational clinical research. Thirteen therapeutic areas were represented. Five categories of mobile devices were identified: (1) inertial sensors, (2) biosensors, (3) pressure sensors and walkways, (4) medication adherence monitors, and (5) location monitors; inertial sensors/accelerometers were most common (reported in 86% of the publications). Among the variety of mobile outcomes, various assessments of physical activity were most common (reported in 74% of the publications). Other mobile outcomes included assessments of sleep, mobility, and pill adherence, as well as biomarkers assessed using a mobile device, including cardiac measures, glucose, gastric reflux, respiratory measures, and intensity of head-related injury. Conclusion Mobile devices are being widely used in clinical research to assess outcomes, although their use in interventional research to assess therapeutic effectiveness is limited. For mobile devices to be used more frequently in pivotal interventional research – such as trials informing regulatory decision-making – more focus should be placed on: (1) consolidating the evidence supporting the clinical meaningfulness of specific mobile outcomes, and (2) standardizing the use of mobile devices in clinical research to measure specific mobile outcomes (e.g., data capture frequencies, placement of device). To that aim, this manuscript offers a broad overview of the various mobile outcome assessments currently used in observational and interventional research, and categorizes and consolidates this information for researchers interested in using mobile devices to assess outcomes in interventional research.
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Affiliation(s)
- Brian Perry
- Department of Population Health Sciences, Duke University School of Medicine, Durham, North Carolina, USA.,Clinical Trials Transformation Initiative, Durham, North Carolina, USA
| | - Will Herrington
- Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Jennifer C Goldsack
- Clinical Trials Transformation Initiative, Durham, North Carolina, USA.,Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Cheryl A Grandinetti
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Kaveeta P Vasisht
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Martin J Landray
- Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Lauren Bataille
- The Michael J. Fox Foundation for Parkinson's Research, New York, New York, USA
| | | | - Corey Bradley
- Duke University Hospital, Durham, North Carolina, USA
| | | | - Elektra J Papadopoulos
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Nirav Sheth
- MicroMedicine, Watertown, Massachusetts, USA
| | - Ken Skodacek
- Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | | | - Marc K Walton
- Janssen Research and Development, Titusville, New Jersey, USA
| | - Amy Corneli
- Department of Population Health Sciences, Duke University School of Medicine, Durham, North Carolina, USA.,Clinical Trials Transformation Initiative, Durham, North Carolina, USA
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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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Heo JY, Kim K, Fava M, Mischoulon D, Papakostas GI, Kim MJ, Kim DJ, Chang KAJ, Oh Y, Yu BH, Jeon HJ. Effects of smartphone use with and without blue light at night in healthy adults: A randomized, double-blind, cross-over, placebo-controlled comparison. J Psychiatr Res 2017; 87:61-70. [PMID: 28017916 DOI: 10.1016/j.jpsychires.2016.12.010] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 10/26/2016] [Accepted: 12/09/2016] [Indexed: 01/20/2023]
Abstract
Smartphones deliver light to users through Light Emitting Diode (LED) displays. Blue light is the most potent wavelength for sleep and mood. This study investigated the immediate effects of smartphone blue light LED on humans at night. We investigated changes in serum melatonin levels, cortisol levels, body temperature, and psychiatric measures with a randomized, double-blind, cross-over, placebo-controlled design of two 3-day admissions. Each subject played smartphone games with either conventional LED or suppressed blue light from 7:30 to 10:00PM (150 min). Then, they were readmitted and conducted the same procedure with the other type of smartphone. Serum melatonin levels were measured in 60-min intervals before, during and after use of the smartphones. Serum cortisol levels and body temperature were monitored every 120 min. The Profile of Mood States (POMS), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and auditory and visual Continuous Performance Tests (CPTs) were administered. Among the 22 participants who were each admitted twice, use of blue light smartphones was associated with significantly decreased sleepiness (Cohen's d = 0.49, Z = 43.50, p = 0.04) and confusion-bewilderment (Cohen's d = 0.53, Z = 39.00, p = 0.02), and increased commission error (Cohen's d = -0.59, t = -2.64, p = 0.02). Also, users of blue light smartphones experienced a longer time to reach dim light melatonin onset 50% (2.94 vs. 2.70 h) and had increases in body temperature, serum melatonin levels, and cortisol levels, although these changes were not statistically significant. Use of blue light LED smartphones at night may negatively influence sleep and commission errors, while it may not be enough to lead to significant changes in serum melatonin and cortisol levels.
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Affiliation(s)
- Jung-Yoon Heo
- Department of Psychiatry, Depression Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Kiwon Kim
- Department of Psychiatry, Depression Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Maurizio Fava
- Depression Clinical and Research Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - David Mischoulon
- Depression Clinical and Research Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - George I Papakostas
- Depression Clinical and Research Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Min-Ji Kim
- Statistics and Data Center, Research Institute for Future Medicine, Samsung Medical Center, Seoul, South Korea
| | - Dong Jun Kim
- Department of Psychiatry, Depression Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Department of Health Sciences & Technology, Department of Medical Device Management and Research, and Department of Clinical Research Design and Evaluation, Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea
| | - Kyung-Ah Judy Chang
- Department of Psychiatry, Depression Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Yunhye Oh
- Department of Psychiatry, Depression Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Bum-Hee Yu
- Department of Psychiatry, Depression Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Hong Jin Jeon
- Department of Psychiatry, Depression Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Depression Clinical and Research Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA; Department of Health Sciences & Technology, Department of Medical Device Management and Research, and Department of Clinical Research Design and Evaluation, Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea.
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Association between light at night, melatonin secretion, sleep deprivation, and the internal clock: Health impacts and mechanisms of circadian disruption. Life Sci 2017; 173:94-106. [PMID: 28214594 DOI: 10.1016/j.lfs.2017.02.008] [Citation(s) in RCA: 330] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 02/02/2017] [Accepted: 02/14/2017] [Indexed: 01/20/2023]
Abstract
Exposure to Artificial Light At Night (ALAN) results in a disruption of the circadian system, which is deleterious to health. In industrialized countries, 75% of the total workforce is estimated to have been involved in shift work and night work. Epidemiologic studies, mainly of nurses, have revealed an association between sustained night work and a 50-100% higher incidence of breast cancer. The potential and multifactorial mechanisms of the effects include the suppression of melatonin secretion by ALAN, sleep deprivation, and circadian disruption. Shift and/or night work generally decreases the time spent sleeping, and it disrupts the circadian time structure. In the long run, this desynchronization is detrimental to health, as underscored by a large number of epidemiological studies that have uncovered elevated rates of several diseases, including cancer, diabetes, cardiovascular risks, obesity, mood disorders and age-related macular degeneration. It amounts to a public health issue in the light of the very substantial number of individuals involved. The IARC has classified shift work in group 2A of "probable carcinogens to humans" since "they involve a circadian disorganization". Countermeasures to the effects of ALAN, such as melatonin, bright light, or psychotropic drugs, have been proposed as a means to combat circadian clock disruption and improve adaptation to shift and night work. We review the evidence for the ALAN impacts on health. Furthermore, we highlight the importance of an in-depth mechanistic understanding to combat the detrimental properties of exposure to ALAN and develop strategies of prevention.
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Wirz-Justice A, Terman M. Commentary on "Blue-blocking glasses as additive treatment for mania: a randomized placebo-controlled trial". Bipolar Disord 2016; 18:383-4. [PMID: 27233225 DOI: 10.1111/bdi.12392] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Anna Wirz-Justice
- Centre for Chronobiology, Psychiatric Hospitals, University of Basel, Basel, Switzerland
| | - Michael Terman
- Department of Psychiatry, Columbia University, New York, NY, USA
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Ayaki M, Hattori A, Maruyama Y, Nakano M, Yoshimura M, Kitazawa M, Negishi K, Tsubota K. Protective effect of blue-light shield eyewear for adults against light pollution from self-luminous devices used at night. Chronobiol Int 2016; 33:134-9. [DOI: 10.3109/07420528.2015.1119158] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Masahiko Ayaki
- Department of Ophthalmology, Keio University School of Medicine , Shinjuku, Tokyo, Japan
| | - Atsuhiko Hattori
- Department of Biology, Tokyo Medical and Dental University , Ichikawa, Chiba, Japan
| | - Yusuke Maruyama
- Department of Biology, Tokyo Medical and Dental University , Ichikawa, Chiba, Japan
| | - Masaki Nakano
- Department of Biology, Tokyo Medical and Dental University , Ichikawa, Chiba, Japan
| | - Michitaka Yoshimura
- Department of Ophthalmology, Keio University School of Medicine , Shinjuku, Tokyo, Japan
| | - Momoko Kitazawa
- Department of Ophthalmology, Keio University School of Medicine , Shinjuku, Tokyo, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine , Shinjuku, Tokyo, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine , Shinjuku, Tokyo, Japan
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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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Touitou Y. Pollution de l’horloge interne par la lumière la nuit, un problème de santé publique. BULLETIN DE L'ACADÉMIE NATIONALE DE MÉDECINE 2015. [DOI: 10.1016/s0001-4079(19)30852-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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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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31
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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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32
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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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Rahman SA, Shapiro CM, Wang F, Ainlay H, Kazmi S, Brown TJ, Casper RF. Effects of filtering visual short wavelengths during nocturnal shiftwork on sleep and performance. Chronobiol Int 2013; 30:951-62. [PMID: 23834705 PMCID: PMC3786545 DOI: 10.3109/07420528.2013.789894] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Circadian phase resetting is sensitive to visual short wavelengths (450-480 nm). Selectively filtering this range of wavelengths may reduce circadian misalignment and sleep impairment during irregular light-dark schedules associated with shiftwork. We examined the effects of filtering short wavelengths (<480 nm) during night shifts on sleep and performance in nine nurses (five females and four males; mean age ± SD: 31.3 ± 4.6 yrs). Participants were randomized to receive filtered light (intervention) or standard indoor light (baseline) on night shifts. Nighttime sleep after two night shifts and daytime sleep in between two night shifts was assessed by polysomnography (PSG). In addition, salivary melatonin levels and alertness were assessed every 2 h on the first night shift of each study period and on the middle night of a run of three night shifts in each study period. Sleep and performance under baseline and intervention conditions were compared with daytime performance on the seventh day shift, and nighttime sleep following the seventh daytime shift (comparator). On the baseline night PSG, total sleep time (TST) (p < 0.01) and sleep efficiency (p = 0.01) were significantly decreased and intervening wake times (wake after sleep onset [WASO]) (p = 0.04) were significantly increased in relation to the comparator night sleep. In contrast, under intervention, TST was increased by a mean of 40 min compared with baseline, WASO was reduced and sleep efficiency was increased to levels similar to the comparator night. Daytime sleep was significantly impaired under both baseline and intervention conditions. Salivary melatonin levels were significantly higher on the first (p < 0.05) and middle (p < 0.01) night shifts under intervention compared with baseline. Subjective sleepiness increased throughout the night under both conditions (p < 0.01). However, reaction time and throughput on vigilance tests were similar to daytime performance under intervention but impaired under baseline on the first night shift. By the middle night shift, the difference in performance was no longer significant between day shift and either of the two night shift conditions, suggesting some adaptation to the night shift had occurred under baseline conditions. These results suggest that both daytime and nighttime sleep are adversely affected in rotating-shift workers and that filtering short wavelengths may be an approach to reduce sleep disruption and improve performance in rotating-shift workers.
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Affiliation(s)
- Shadab A Rahman
- Fran and Lawrence Bloomberg Department of Obstetrics and Gynecology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
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Boivin DB, Boudreau P, James FO, Kin NMKNY. Photic resetting in night-shift work: impact on nurses' sleep. Chronobiol Int 2012; 29:619-28. [PMID: 22621359 DOI: 10.3109/07420528.2012.675257] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The objective of this study was to quantify daytime sleep in night-shift workers with and without an intervention designed to recover the normal relationship between the endogenous circadian pacemaker and the sleep/wake cycle. Workers of the treatment group received intermittent exposure to full-spectrum bright light during night shifts and wore dark goggles during the morning commute home. All workers maintained stable 8-h daytime sleep/darkness schedules. The authors found that workers of the treatment group had daytime sleep episodes that lasted 7.1 ± .1 h (mean ± SEM) versus 6.6 ± .2 h for workers in the control group (p = .04). The increase in total sleep time co-occurred with a larger proportion of the melatonin secretory episode during daytime sleep in workers of the treatment group. The results of this study showed reestablishment of a phase angle that is comparable to that observed on a day-oriented schedule favors longer daytime sleep episodes in night-shift workers. (Author correspondence: diane.boivin@douglas.mcgill.ca ).
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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, Montréal, Québec, Canada.
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Martin JS, Hébert M, Ledoux E, Gaudreault M, Laberge L. Relationship of chronotype to sleep, light exposure, and work-related fatigue in student workers. Chronobiol Int 2012; 29:295-304. [PMID: 22390242 DOI: 10.3109/07420528.2011.653656] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Students who work during the school year face the potential of sleep deprivation and its effects, since they have to juggle between school and work responsibilities along with social life. This may leave them with less time left for sleep than their nonworking counterparts. Chronotype is a factor that may exert an influence on the sleep of student workers. Also, light and social zeitgebers may have an impact on the sleep-related problems of this population. This study aimed to document sleep, light exposure patterns, social rhythms, and work-related fatigue of student workers aged 19-21 yrs and explore possible associations with chronotype. A total of 88 student workers (mean ± SD: 20.18 ± .44 yrs of age; 36 males/52 females) wore an actigraph (Actiwatch-L; Mini-Mitter/Respironics,Bend, OR) and filled out the Social Rhythm Metric for two consecutive weeks during the school year. Also, they completed the Morningness-Eveningness Questionnaire (MEQ), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Occupational Fatigue Exhaustion/Recovery Scale (OFER). Repeated and one-way analyses of variance (ANOVAs), Pearson's chi-square tests, and correlation coefficients were used for statistical comparisons. Subjects slept an average of 06:28 h/night. Actigraphic sleep parameters, such as sleep duration, sleep efficiency, wake after sleep onset, and sleep latency, did not differ between chronotypes. Results also show that evening types (n = 17) presented lower subjective sleep quality than intermediate types (n = 58) and morning types (n = 13). Moreover, evening types reported higher levels of chronic work-related fatigue, exhibited less regular social rhythms, and were exposed to lower levels of light during their waking hours (between 2 and 11 h after wake time) as compared to intermediate types and morning types. In addition, exposure to light intensities between 100 and 500 lux was lower in evening types than in intermediate types and morning types. However, bright light exposure (≥ 1000 lux) did not differ between chronotypes. In conclusion, results suggest that student workers may constitute a high-risk population for sleep deprivation. Evening types seemed to cope less well with sleep deprivation, reporting poorer sleep quality and higher levels of work-related fatigue than intermediate types and morning types. The higher chronic work-related fatigue of evening types may be linked to their attenuated level of light exposure and weaker social zeitgebers. These results add credence to the hypothesis that eveningness entails a higher risk of health-impairing behaviors.
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Boivin DB, Boudreau P, Tremblay GM. Phototherapy and Orange-Tinted Goggles for Night-Shift Adaptation of Police Officers on Patrol. Chronobiol Int 2012; 29:629-40. [DOI: 10.3109/07420528.2012.675252] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Shikder S, Mourshed M, Price A. Therapeutic lighting design for the elderly: a review. Perspect Public Health 2011; 132:282-91. [PMID: 23111083 DOI: 10.1177/1757913911422288] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AIMS Research suggests that specialised lighting design is essential to cater for the elderly users of a building because of reduced visual performance with increased age. This review aims to document what is known of the physical and psychological aspects of lighting and their role in promoting a healthy and safe environment for the elderly. METHODS A methodical review was carried out of published literature on the physical and psychological impacts of light on the elderly. Design standards and guides from professional organizations were evaluated to identify synergies and gaps between the evidence base and current practice. RESULTS Lighting has been identified as a significant environmental attribute responsible for promoting physical and mental health of the elderly. The evidence related to visual performance was found to be robust. However, guides and standards appeared to have focused mostly on illumination requirements for specific tasks and have lacked detailed guidelines on vertical lighting and luminance design. This review has identified a growing body of evidence on the therapeutic benefits of lighting and its use in treating psychological disorders among the elderly. The experiments using light as a therapy have improved our understanding of the underlying principles, but the integration of therapeutic aspects of lighting in design practice and guidelines is lacking. CONCLUSIONS While design guidelines discuss the physical needs of lighting for the elderly fairly well, they lack incorporation of photobiological impacts. Despite positive outcomes from research, the implementation of therapeutic aspects of lighting in buildings is still debatable due to insufficient relevant investigations and robustness of their findings. Collaborations between designers and physicians can contribute in delivering customised lighting solutions by considering disease types and needs. Further investigation needs to be carried out for translating therapeutic benefits to photometric units to implement them in building lighting design.
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Affiliation(s)
- Shariful Shikder
- School of Civil and Building Engineering, Loughborough University, Leicestershire, LE11 3TU, UK.
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