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Höhn C, Hahn MA, Gruber G, Pletzer B, Cajochen C, Hoedlmoser K. Effects of evening smartphone use on sleep and declarative memory consolidation in male adolescents and young adults. Brain Commun 2024; 6:fcae173. [PMID: 38846535 PMCID: PMC11154150 DOI: 10.1093/braincomms/fcae173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/08/2024] [Accepted: 05/16/2024] [Indexed: 06/09/2024] Open
Abstract
Exposure to short-wavelength light before bedtime is known to disrupt nocturnal melatonin secretion and can impair subsequent sleep. However, while it has been demonstrated that older adults are less affected by short-wavelength light, there is limited research exploring differences between adolescents and young adults. Furthermore, it remains unclear whether the effects of evening short-wavelength light on sleep architecture extend to sleep-related processes, such as declarative memory consolidation. Here, we recorded polysomnography from 33 male adolescents (15.42 ± 0.97 years) and 35 male young adults (21.51 ± 2.06 years) in a within-subject design during three different nights to investigate the impact of reading for 90 min either on a smartphone with or without a blue-light filter or from a printed book. We measured subjective sleepiness, melatonin secretion, sleep physiology and sleep-dependent memory consolidation. While subjective sleepiness remained unaffected, we observed a significant melatonin attenuation effect in both age groups immediately after reading on the smartphone without a blue-light filter. Interestingly, adolescents fully recovered from the melatonin attenuation in the following 50 min before bedtime, whereas adults still, at bedtime, exhibited significantly reduced melatonin levels. Sleep-dependent memory consolidation and the coupling between sleep spindles and slow oscillations were not affected by short-wavelength light in both age groups. Nevertheless, adults showed a reduction in N3 sleep during the first night quarter. In summary, avoiding smartphone use in the last hour before bedtime is advisable for adolescents and young adults to prevent sleep disturbances. Our research empirically supports general sleep hygiene advice and can inform future recommendations regarding the use of smartphones and other screen-based devices before bedtime.
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Affiliation(s)
- Christopher Höhn
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, Paris Lodron University of Salzburg, 5020 Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), Paris Lodron University of Salzburg, 5020 Salzburg, Austria
| | - Michael A Hahn
- Hertie-Institute for Clinical Brain Research, University Medical Center Tübingen, 72076 Tübingen, Germany
| | - Georg Gruber
- The Siesta Group Schlafanalyse GmbH, 1210 Vienna, Austria
| | - Belinda Pletzer
- Centre for Cognitive Neuroscience Salzburg (CCNS), Paris Lodron University of Salzburg, 5020 Salzburg, Austria
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4002 Basel, Switzerland
- Research Cluster Molecular and Cognitive Neuroscience (MCN), University of Basel, 4055 Basel, Switzerland
| | - Kerstin Hoedlmoser
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, Paris Lodron University of Salzburg, 5020 Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), Paris Lodron University of Salzburg, 5020 Salzburg, Austria
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Ballae Ganeshrao S, Theruveethi N, Srinivasan K. Knowledge, perception and practice towards blue-blocking lenses among optometrists. Clin Exp Optom 2024; 107:332-340. [PMID: 37257458 DOI: 10.1080/08164622.2023.2215380] [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: 01/12/2022] [Revised: 12/22/2022] [Accepted: 05/09/2023] [Indexed: 06/02/2023] Open
Abstract
CLINICAL RELEVANCE There is a lack of clinical guidelines in India for the prescription of blue-blocking lenses. Therefore, the practice trends will depend on practitioners' knowledge, attitude, and perception. BACKGROUND Exposure to blue light with increased use of light-emitting diode (LED) lights and digital devices along with the commercial availability of blue blocking lenses has warranted the need to understand the factors that influence the prescription of blue blocking lenses among eye care practitioners. Hence, we aim to assess knowledge, perception, and practice pattern of blue blocking lenses among Indian optometrists. METHODS This cross-sectional online survey was conducted among Indian Optometrists. The survey was distributed through various social groups of optometrists and state associations. The questionnaire had four main domains with 29 items in total. The four major domains were knowledge, practice, perception and demographic details on education. Descriptive analysis and logistic regression were performed to study the impact of these domains on the prescription of blue block lenses. RESULTS Out of 341 responses, 247 were included for analysis as per study criteria. About 50% (n = 123) of the participants had appropriate knowledge about blue light. Blue-blocking lenses were prescribed always or most of the time by 52% (n = 130) of the participants. The odds of prescribing blue blocking lenses were higher among practitioners who considered blue light as an important factor in causing computer vision syndrome (OR 3.77, 95% CI: 1.33-10.69, P = 0.01) or if they considered there is adequate published evidence (OR 3.95, 95% CI: 1.58-9.87, P = 0.003). CONCLUSIONS The source of evidence for prescribing blue-blocking lenses for our participants was mainly from advertisements rather than from scientific studies. Factors such as awareness, knowledge, education, and nature of practice did not play a significant role in prescribing blue-blocking lenses. This raises the need for evidence-based practice and the development of practice guidelines for prescribing blue-blocking lenses.
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Affiliation(s)
- Shonraj Ballae Ganeshrao
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India
| | - Nagarajan Theruveethi
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India
| | - Krithica Srinivasan
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India
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Zhong Z, Tan X, An X, Li J, Cai J, Jiang Y, Taufique SKT, Li B, Shi Q, Zhao M, Wang Y, Luo Q, Wang H. Administration of blue light in the morning and no blue-ray light in the evening improves the circadian functions of non-24-hour shift workers. Chronobiol Int 2024; 41:267-282. [PMID: 38267234 DOI: 10.1080/07420528.2024.2305218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 01/07/2024] [Indexed: 01/26/2024]
Abstract
In modern 24-hour society, various round-the-clock services have entailed shift work, resulting in non-24-hour schedules. However, the extent of behavioral and physiological alterations by non-24-hour schedules remains unclear, and particularly, effective interventions to restore the circadian functions of non-24-hour shift workers are rarely explored. In this study, we investigate the effects of a simulated non-24-hour military shift work schedule on daily rhythms and sleep, and establish an intervention measure to restore the circadian functions of non-24-hour shift workers. The three stages of experiments were conducted. The stage-one experiment was to establish a comprehensive evaluation index of the circadian rhythms and sleep for all 60 participants by analyzing wristwatch-recorded physiological parameters and sleep. The stage-two experiment evaluated the effects of an intervention strategy on physiological rhythms and sleep. The stage-three experiment was to examine the participants' physiological and behavioral disturbances under the simulated non-24-hour military shift work schedule and their improvements by the optimal lighting apparatus. We found that wristwatch-recorded physiological parameters display robust rhythmicity, and the phases of systolic blood pressures and heart rates can be used as reliable estimators for the human body time. The simulated non-24-hour military shift work schedule significantly disrupts the daily rhythms of oxygen saturation levels, blood pressures, heart rates, and reduces sleep quality. Administration of blue light in the morning and no blue-ray light in the evening improves the amplitude and synchronization of daily rhythms of the non-24-hour participants. These findings demonstrate the harmful consequences of the non-24-hour shift work schedule and provide a non-invasive strategy to improve the well-being and work efficiency of the non-24-hour shift population.
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Affiliation(s)
- Zhaomin Zhong
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Xiaohui Tan
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Xingna An
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Jie Li
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Jing Cai
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Yunchun Jiang
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - S K Tahajjul Taufique
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Bo Li
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Quan Shi
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Meng Zhao
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Yali Wang
- Department of Neurology, Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Qun Luo
- Naval Medical Center, PLA Naval Medical University, Shanghai, China
| | - Han Wang
- Center for Circadian Clocks, Soochow University, Suzhou, Jiangsu, China
- School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
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Madsen HØ, Hageman I, Martiny K, Faurholt-Jepsen M, Kolko M, Henriksen TEG, Kessing LV. BLUES - stabilizing mood and sleep with blue blocking eyewear in bipolar disorder - a randomized controlled trial study protocol. Ann Med 2023; 55:2292250. [PMID: 38109922 PMCID: PMC10732202 DOI: 10.1080/07853890.2023.2292250] [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] [Received: 09/10/2023] [Accepted: 11/26/2023] [Indexed: 12/20/2023] Open
Abstract
INTRODUCTION Chronotherapeutic interventions for bipolar depression and mania are promising interventions associated with rapid response and benign side effect profiles. Filtering of biologically active short wavelength (blue) light by orange tinted eyewear has been shown to induce antimanic and sleep promoting effects in inpatient mania. We here describe a study protocol assessing acute and long-term stabilizing effects of blue blocking (BB) glasses in outpatient treatment of bipolar disorder. PATIENTS AND METHODS A total of 150 outpatients with bipolar disorder and current symptoms of (hypo)-mania will be randomized 1:1 to wear glasses with either high (99%) (intervention group) or low (15%) (control group) filtration of short wavelength light (<500 nm). Following a baseline assessment including ratings of manic and depressive symptoms, sleep questionnaires, pupillometric evaluation and 48-h actigraphy, participants will wear the glasses from 6 PM to 8 AM for 7 consecutive days. The primary outcome is the between group difference in change in Young Mania Rating Scale scores after 7 days of intervention (day 9). Following the initial treatment period, the long-term stabilizing effects on mood and sleep will be explored in a 3-month treatment paradigm, where the period of BB treatment is tailored to the current symptomatology using a 14-h antimanic schedule during (hypo-) manic episodes (BB glasses or dark bedroom from 6 PM to 8 AM) and a 2-h maintenance schedule (BB glasses on two hours prior to bedtime/dark bedroom) during euthymic and depressive states.The assessments will be repeated at follow-up visits after 1 and 3 months. Throughout the 3-month study period, participants will perform continuous daily self-monitoring of mood, sleep and activity in a smartphone-based app. Secondary outcomes include between-group differences in actigraphic sleep parameters on day 9 and in day-to-day instability in mood, sleep and activity, general functioning and objective sleep markers (actigraphy) at weeks 5 and 15. TRIAL REGISTRATION The trial will be registered at www.clinicaltrials.gov prior to initiation and has not yet received a trial reference. ADMINISTRATIVE INFORMATION The current paper is based on protocol version 1.0_31.07.23. Trial sponsor: Lars Vedel Kessing.
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Affiliation(s)
- Helle Østergaard Madsen
- Copenhagen Affective Disorder Research Centre (CADIC), Mental Health Centre Copenhagen, Copenhagen, Denmark
| | - Ida Hageman
- Mental Health Services, Capital Region of Denmark, Copenhagen, Denmark
| | - Klaus Martiny
- Copenhagen Affective Disorder Research Centre (CADIC), Mental Health Centre Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria Faurholt-Jepsen
- Copenhagen Affective Disorder Research Centre (CADIC), Mental Health Centre Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Miriam Kolko
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Tone E. G. Henriksen
- Department of Research and Innovation, Division of Mental Health Care, Valen Hospital, Fonna Health Authority, Kvinnherad, Norway
| | - Lars Vedel Kessing
- Copenhagen Affective Disorder Research Centre (CADIC), Mental Health Centre Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Kalkanis A, Demolder S, Papadopoulos D, Testelmans D, Buyse B. Recovery from shift work. Front Neurol 2023; 14:1270043. [PMID: 38020633 PMCID: PMC10651732 DOI: 10.3389/fneur.2023.1270043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023] Open
Abstract
One fifth of today's workforce is engaged in shift work and exposed to various mental and physical health risks including shift work disorder. Efficiently recovering from shift work through physical and mental interventions allows us to mitigate negative effects on health, enables a better work-life balance and enhances our overall wellbeing. The aim of this review is to provide a state-of-the-art overview of the available literature. The role of sleep timing and naps, light therapy and psychotherapy, diet and exercise in recovery from shift work is presented here. We further review the impact of shift schedules and social support on post-shift unwinding.
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Affiliation(s)
- Alexandros Kalkanis
- Department of Respiratory Diseases, Louvain University Center for Sleep and Wake Disorders (LUCS), University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Saartje Demolder
- Department of Respiratory Diseases, Louvain University Center for Sleep and Wake Disorders (LUCS), University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Dimitrios Papadopoulos
- Department of Respiratory Diseases, Louvain University Center for Sleep and Wake Disorders (LUCS), University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Dries Testelmans
- Department of Respiratory Diseases, Louvain University Center for Sleep and Wake Disorders (LUCS), University Hospitals Leuven, KU Leuven, Leuven, Belgium
- Laboratory of Respiratory Disease and Thoracic Surgery (BREATH), KU Leuven-University, Leuven, Belgium
| | - Bertien Buyse
- Department of Respiratory Diseases, Louvain University Center for Sleep and Wake Disorders (LUCS), University Hospitals Leuven, KU Leuven, Leuven, Belgium
- Laboratory of Respiratory Disease and Thoracic Surgery (BREATH), KU Leuven-University, Leuven, Belgium
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Singh S, Keller PR, Busija L, McMillan P, Makrai E, Lawrenson JG, Hull CC, Downie LE. Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database Syst Rev 2023; 8:CD013244. [PMID: 37593770 PMCID: PMC10436683 DOI: 10.1002/14651858.cd013244.pub2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
BACKGROUND 'Blue-light filtering', or 'blue-light blocking', spectacle lenses filter ultraviolet radiation and varying portions of short-wavelength visible light from reaching the eye. Various blue-light filtering lenses are commercially available. Some claims exist that they can improve visual performance with digital device use, provide retinal protection, and promote sleep quality. We investigated clinical trial evidence for these suggested effects, and considered any potential adverse effects. OBJECTIVES To assess the effects of blue-light filtering lenses compared with non-blue-light filtering lenses, for improving visual performance, providing macular protection, and improving sleep quality in adults. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL; containing the Cochrane Eyes and Vision Trials Register; 2022, Issue 3); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and WHO ICTRP, with no date or language restrictions. We last searched the electronic databases on 22 March 2022. SELECTION CRITERIA We included randomised controlled trials (RCTs), involving adult participants, where blue-light filtering spectacle lenses were compared with non-blue-light filtering spectacle lenses. DATA COLLECTION AND ANALYSIS Primary outcomes were the change in visual fatigue score and critical flicker-fusion frequency (CFF), as continuous outcomes, between baseline and one month of follow-up. Secondary outcomes included best-corrected visual acuity (BCVA), contrast sensitivity, discomfort glare, proportion of eyes with a pathological macular finding, colour discrimination, proportion of participants with reduced daytime alertness, serum melatonin levels, subjective sleep quality, and patient satisfaction with their visual performance. We evaluated findings related to ocular and systemic adverse effects. We followed standard Cochrane methods for data extraction and assessed risk of bias using the Cochrane Risk of Bias 1 (RoB 1) tool. We used GRADE to assess the certainty of the evidence for each outcome. MAIN RESULTS We included 17 RCTs, with sample sizes ranging from five to 156 participants, and intervention follow-up periods from less than one day to five weeks. About half of included trials used a parallel-arm design; the rest adopted a cross-over design. A variety of participant characteristics was represented across the studies, ranging from healthy adults to individuals with mental health and sleep disorders. None of the studies had a low risk of bias in all seven Cochrane RoB 1 domains. We judged 65% of studies to have a high risk of bias due to outcome assessors not being masked (detection bias) and 59% to be at high risk of bias of performance bias as participants and personnel were not masked. Thirty-five per cent of studies were pre-registered on a trial registry. We did not perform meta-analyses for any of the outcome measures, due to lack of available quantitative data, heterogenous study populations, and differences in intervention follow-up periods. There may be no difference in subjective visual fatigue scores with blue-light filtering lenses compared to non-blue-light filtering lenses, at less than one week of follow-up (low-certainty evidence). One RCT reported no difference between intervention arms (mean difference (MD) 9.76 units (indicating worse symptoms), 95% confidence interval (CI) -33.95 to 53.47; 120 participants). Further, two studies (46 participants, combined) that measured visual fatigue scores reported no significant difference between intervention arms. There may be little to no difference in CFF with blue-light filtering lenses compared to non-blue-light filtering lenses, measured at less than one day of follow-up (low-certainty evidence). One study reported no significant difference between intervention arms (MD - 1.13 Hz lower (indicating poorer performance), 95% CI - 3.00 to 0.74; 120 participants). Another study reported a less negative change in CFF (indicating less visual fatigue) with high- compared to low-blue-light filtering and no blue-light filtering lenses. Compared to non-blue-light filtering lenses, there is probably little or no effect with blue-light filtering lenses on visual performance (BCVA) (MD 0.00 logMAR units, 95% CI -0.02 to 0.02; 1 study, 156 participants; moderate-certainty evidence), and unknown effects on daytime alertness (2 RCTs, 42 participants; very low-certainty evidence); uncertainty in these effects was due to lack of available data and the small number of studies reporting these outcomes. We do not know if blue-light filtering spectacle lenses are equivalent or superior to non-blue-light filtering spectacle lenses with respect to sleep quality (very low-certainty evidence). Inconsistent findings were evident across six RCTs (148 participants); three studies reported a significant improvement in sleep scores with blue-light filtering lenses compared to non-blue-light filtering lenses, and the other three studies reported no significant difference between intervention arms. We noted differences in the populations across studies and a lack of quantitative data. Device-related adverse effects were not consistently reported (9 RCTs, 333 participants; low-certainty evidence). Nine studies reported on adverse events related to study interventions; three studies described the occurrence of such events. Reported adverse events related to blue-light filtering lenses were infrequent, but included increased depressive symptoms, headache, discomfort wearing the glasses, and lower mood. Adverse events associated with non-blue-light filtering lenses were occasional hyperthymia, and discomfort wearing the spectacles. We were unable to determine whether blue-light filtering lenses affect contrast sensitivity, colour discrimination, discomfort glare, macular health, serum melatonin levels or overall patient visual satisfaction, compared to non-blue-light filtering lenses, as none of the studies evaluated these outcomes. AUTHORS' CONCLUSIONS This systematic review found that blue-light filtering spectacle lenses may not attenuate symptoms of eye strain with computer use, over a short-term follow-up period, compared to non-blue-light filtering lenses. Further, this review found no clinically meaningful difference in changes to CFF with blue-light filtering lenses compared to non-blue-light filtering lenses. Based on the current best available evidence, there is probably little or no effect of blue-light filtering lenses on BCVA compared with non-blue-light filtering lenses. Potential effects on sleep quality were also indeterminate, with included trials reporting mixed outcomes among heterogeneous study populations. There was no evidence from RCT publications relating to the outcomes of contrast sensitivity, colour discrimination, discomfort glare, macular health, serum melatonin levels, or overall patient visual satisfaction. Future high-quality randomised trials are required to define more clearly the effects of blue-light filtering lenses on visual performance, macular health and sleep, in adult populations.
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Affiliation(s)
- Sumeer Singh
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Peter R Keller
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Ljoudmila Busija
- Biostatistics Unit, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Patrick McMillan
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Eve Makrai
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - John G Lawrenson
- Centre for Applied Vision Research, School of Health Sciences, City University of London, London, UK
| | - Christopher C Hull
- Centre for Applied Vision Research, School of Health Sciences, City University of London, London, UK
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
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Kureshi S, Stowe C, Francis J, Djalilian H. Circadian therapy interventions for glymphatic dysfunction in concussions injuries: A narrative review. Sci Prog 2023; 106:368504231189536. [PMID: 37499049 PMCID: PMC10388340 DOI: 10.1177/00368504231189536] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
There are two primary threats to the brain after concussion. The first is a buildup of neurotoxic proteins in the brain. The second, a partial consequence of the first, is a sustained neuroinflammatory response that may lead to central sensitization and the development of persistent post-concussive symptoms. These threats make neurotoxin clearance a high clinical priority in the acute period after injury. The glymphatic system is the brain's primary mechanism for clearing neurotoxic waste. The glymphatic system is intimately tied to the sleep cycle and circadian dynamics. However, glymphatic dysfunction and sleep disturbances are nearly ubiquitous in the acute period after concussion injury. Because of this, sleep optimization via circadian therapy is a time-sensitive and critical tool in acute concussion management.
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Affiliation(s)
- Sohaib Kureshi
- Neurosurgical Medical Clinic, San Diego, CA, USA
- TBI Virtual, San Diego, CA, USA
| | | | | | - Hamid Djalilian
- TBI Virtual, San Diego, CA, USA
- Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, CA, USA
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Swanson LM, Raglan GB. Circadian Interventions as Adjunctive Therapies to Cognitive-Behavioral Therapy for Insomnia. Sleep Med Clin 2023; 18:21-30. [PMID: 36764783 PMCID: PMC10015491 DOI: 10.1016/j.jsmc.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The circadian system plays a key role in the sleep-wake cycle. A mismatch between the behavioral timing of sleep and the circadian timing of sleepiness/alertness can contribute to insomnia. Patients who report primarily difficulty falling asleep or early morning awakenings may benefit from circadian interventions administered adjunctively to cognitive-behavioral therapy for insomnia. Specific circadian interventions that clinicians may consider include bright light therapy, scheduled dim light, blue-blocking glasses, and melatonin. Implementation of these interventions differs depending on the patient's insomnia subtype. Further, careful attention must be paid to the timing of these interventions to ensure they are administered correctly.
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Affiliation(s)
- Leslie M Swanson
- Department of Psychiatry, University of Michigan, 4250 Plymouth Road, Ann Arbor, MI 48105, USA.
| | - Greta B Raglan
- Department of Psychiatry, University of Michigan, 4250 Plymouth Road, Ann Arbor, MI 48105, USA
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9
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Kawada T. Comment on "Effect of blue light-filtering intraocular lenses on insomnia after cataract surgery: A nationwide cohort study with 10-year follow-up". Am J Ophthalmol 2023; 247:200. [PMID: 36493847 DOI: 10.1016/j.ajo.2022.11.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 11/16/2022] [Indexed: 12/12/2022]
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Abstract
Despite sleep's fundamental role in maintaining and improving physical and mental health, many people get less than the recommended amount of sleep or suffer from sleeping disorders. This review highlights sleep's instrumental biological functions, various sleep problems, and sleep hygiene and lifestyle interventions that can help improve sleep quality. Quality sleep allows for improved cardiovascular health, mental health, cognition, memory consolidation, immunity, reproductive health, and hormone regulation. Sleep disorders, such as insomnia, sleep apnea, and circadian-rhythm-disorders, or disrupted sleep from lifestyle choices, environmental conditions, or other medical issues can lead to significant morbidity and can contribute to or exacerbate medical and psychiatric conditions. The best treatment for long-term sleep improvement is proper sleep hygiene through behavior and sleep habit modification. Recommendations to improve sleep include achieving 7 to 9 h of sleep, maintaining a consistent sleep/wake schedule, a regular bedtime routine, engaging in regular exercise, and adopting a contemplative practice. In addition, avoiding many substances late in the day can help improve sleep. Caffeine, alcohol, heavy meals, and light exposure later in the day are associated with fragmented poor-quality sleep. These sleep hygiene practices can promote better quality and duration of sleep, with corresponding health benefits.
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11
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Zhang R, Volkow ND. Seasonality of brain function: role in psychiatric disorders. Transl Psychiatry 2023; 13:65. [PMID: 36813773 PMCID: PMC9947162 DOI: 10.1038/s41398-023-02365-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/24/2023] Open
Abstract
Seasonality patterns are reported in various psychiatric disorders. The current paper summarizes findings on brain adaptations associated with seasonal changes, factors that contribute to individual differences and their implications for psychiatric disorders. Changes in circadian rhythms are likely to prominently mediate these seasonal effects since light strongly entrains the internal clock modifying brain function. Inability of circadian rhythms to accommodate to seasonal changes might increase the risk for mood and behavior problems as well as worse clinical outcomes in psychiatric disorders. Understanding the mechanisms that account for inter-individual variations in seasonality is relevant to the development of individualized prevention and treatment for psychiatric disorders. Despite promising findings, seasonal effects are still understudied and only controlled as a covariate in most brain research. Rigorous neuroimaging studies with thoughtful experimental designs, powered sample sizes and high temporal resolution alongside deep characterization of the environment are needed to better understand the seasonal adaptions of the human brain as a function of age, sex, and geographic latitude and to investigate the mechanisms underlying the alterations in seasonal adaptation in psychiatric disorders.
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Affiliation(s)
- Rui Zhang
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892-1013, USA.
| | - Nora D. Volkow
- grid.94365.3d0000 0001 2297 5165Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892-1013 USA
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Meléndez-Fernández OH, Liu JA, Nelson RJ. Circadian Rhythms Disrupted by Light at Night and Mistimed Food Intake Alter Hormonal Rhythms and Metabolism. Int J Mol Sci 2023; 24:3392. [PMID: 36834801 PMCID: PMC9963929 DOI: 10.3390/ijms24043392] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/04/2023] [Accepted: 02/07/2023] [Indexed: 02/10/2023] Open
Abstract
Availability of artificial light and light-emitting devices have altered human temporal life, allowing 24-hour healthcare, commerce and production, and expanding social life around the clock. However, physiology and behavior that evolved in the context of 24 h solar days are frequently perturbed by exposure to artificial light at night. This is particularly salient in the context of circadian rhythms, the result of endogenous biological clocks with a rhythm of ~24 h. Circadian rhythms govern the temporal features of physiology and behavior, and are set to precisely 24 h primarily by exposure to light during the solar day, though other factors, such as the timing of meals, can also affect circadian rhythms. Circadian rhythms are significantly affected by night shift work because of exposure to nocturnal light, electronic devices, and shifts in the timing of meals. Night shift workers are at increased risk for metabolic disorder, as well as several types of cancer. Others who are exposed to artificial light at night or late mealtimes also show disrupted circadian rhythms and increased metabolic and cardiac disorders. It is imperative to understand how disrupted circadian rhythms alter metabolic function to develop strategies to mitigate their negative effects. In this review, we provide an introduction to circadian rhythms, physiological regulation of homeostasis by the suprachiasmatic nucleus (SCN), and SCN-mediated hormones that display circadian rhythms, including melatonin and glucocorticoids. Next, we discuss circadian-gated physiological processes including sleep and food intake, followed by types of disrupted circadian rhythms and how modern lighting disrupts molecular clock rhythms. Lastly, we identify how disruptions to hormones and metabolism can increase susceptibility to metabolic syndrome and risk for cardiovascular diseases, and discuss various strategies to mitigate the harmful consequences associated with disrupted circadian rhythms on human health.
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Effects of Morning or Evening Narrow-band Blue Light on the Compensation to Lens-induced Hyperopic Defocus in Chicks. Optom Vis Sci 2023; 100:33-42. [PMID: 36473083 DOI: 10.1097/opx.0000000000001967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SIGNIFICANCE Exposure to blue light before bedtime is purported to be deleterious to various aspects of human health. In chicks, blue evening light stimulated ocular growth, suggesting a role in myopia development. To further investigate this hypothesis, we asked if brief blue light altered the compensatory responses to hyperopic defocus. PURPOSE Previous work showed that several hours' evening exposure to blue light stimulated ocular growth in chicks, but morning exposure was only effective at a lower illuminance. By contrast, rearing in blue light has inhibited ocular growth in untreated eyes and eyes exposed to form deprivation or defocus. We studied the effects of brief exposures to blue light on the compensation to hyperopic defocus. METHODS Chicks wore monocular negative lenses (-10 D) starting at age 10 days. They were subsequently exposed to blue light (460 nm) for 4 hours in the morning or evening for 8 to 9 days ("dim," 200 lux[morning, n = 9; evening, n = 11]; "bright," 600 lux[morning, n = 8; evening, n = 20]); controls wore lenses in white light (n = 14). Ultrasonography was done on days 1, 5, 8, and 9 for "evening" groups and days 1, 6, and 8 for "morning." All data are reported as interocular differences (experimental minus fellow eyes). Refractions were measured on the last day. RESULTS For evening exposure, dim blue light enhanced the axial compensation at all times (change in axial length: day 6: 465 vs. 329 μm/9 days, analysis of variance P < .001, P = .03; day 9: 603 vs. 416 μm/9 days, analysis of variance P < .001; P < .05). Bright blue light had a transient inhibitory effect (day 5: 160 vs. 329 μm; P < .005). Refractive errors were consistent with axial growth, with dim causing more myopia than bright (-9.4 vs. -4.7 D; P < .05). Morning blue light had no significant effect. CONCLUSIONS We speculate that these findings reflect a complex interaction between illuminance, defocus, and time of day.
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Is Melatonin the “Next Vitamin D”?: A Review of Emerging Science, Clinical Uses, Safety, and Dietary Supplements. Nutrients 2022; 14:nu14193934. [PMID: 36235587 PMCID: PMC9571539 DOI: 10.3390/nu14193934] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/17/2022] Open
Abstract
Melatonin has become a popular dietary supplement, most known as a chronobiotic, and for establishing healthy sleep. Research over the last decade into cancer, Alzheimer’s disease, multiple sclerosis, fertility, PCOS, and many other conditions, combined with the COVID-19 pandemic, has led to greater awareness of melatonin because of its ability to act as a potent antioxidant, immune-active agent, and mitochondrial regulator. There are distinct similarities between melatonin and vitamin D in the depth and breadth of their impact on health. Both act as hormones, affect multiple systems through their immune-modulating, anti-inflammatory functions, are found in the skin, and are responsive to sunlight and darkness. In fact, there may be similarities between the widespread concern about vitamin D deficiency as a “sunlight deficiency” and reduced melatonin secretion as a result of “darkness deficiency” from overexposure to artificial blue light. The trend toward greater use of melatonin supplements has resulted in concern about its safety, especially higher doses, long-term use, and application in certain populations (e.g., children). This review aims to evaluate the recent data on melatonin’s mechanisms, its clinical uses beyond sleep, safety concerns, and a thorough summary of therapeutic considerations concerning dietary supplementation, including the different formats available (animal, synthetic, and phytomelatonin), dosing, timing, contraindications, and nutrient combinations.
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Wong NA, Bahmani H. A review of the current state of research on artificial blue light safety as it applies to digital devices. Heliyon 2022; 8:e10282. [PMID: 36042717 PMCID: PMC9420367 DOI: 10.1016/j.heliyon.2022.e10282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/13/2022] [Accepted: 08/09/2022] [Indexed: 12/24/2022] Open
Abstract
Light is necessary for human health and well-being. As we spend more time indoors, we are being increasingly exposed to artificial light. The development of artificial lighting has allowed us to control the brightness, colour, and timing of our light exposure. Yet, the widespread use of artificial light has raised concerns about the impact of altering our light environment on our health. The widespread adoption of personal digital devices over the past decade has exposed us to yet another source of artificial light. We spend a significant amount of time using digital devices with light-emitting screens, including smartphones and tablets, at close range. The light emitted from these devices, while appearing white, has an emission spectrum with a peak in the blue range. Blue light is often characterised as hazardous as its photon energy is higher than that of other wavelengths of visible light. Under certain conditions, visible blue light can cause harm to the retina and other ocular structures. Blue light can also influence the circadian rhythm and processes mediated by melanopsin-expressing intrinsically photosensitive retinal ganglion cells. While the blue component of sunlight is necessary for various physiological processes, whether the low-illuminance artificial blue light emitted from digital devices presents a risk to our health remains an ongoing area of debate. As technological advancements continue, it is relevant to understand how new devices may influence our well-being. This review examines the existing research on artificial blue light safety and the eye, visual performance, and circadian functions.
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Affiliation(s)
| | - Hamed Bahmani
- Dopavision GmbH, Berlin, Germany.,Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
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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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Effects of dynamic bedroom lighting on measures of sleep and circadian rest-activity rhythm in inpatients with major depressive disorder. Sci Rep 2022; 12:6137. [PMID: 35414714 PMCID: PMC9005730 DOI: 10.1038/s41598-022-10161-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 04/01/2022] [Indexed: 11/08/2022] Open
Abstract
Bright light therapy is an effective treatment option for seasonal and non-seasonal affective disorders. However up to now, no study has investigated effects of dynamic bedroom lighting in hospitalized patients with major depression. A bedroom lighting system, which automatically delivered artificial dawn and dusk and blue-depleted nighttime lighting (DD-N lighting) was installed in a psychiatric ward. Patients with moderate to severe depression were randomly assigned to stay in bedrooms with the new lighting or standard lighting system. Patients wore wrist actimeters during the first two treatment weeks. Additionally, hospitalization duration and daily psychotropic medication were retrieved from patients' medical charts. Data from thirty patients, recorded over a period of two weeks, were analyzed. Patients under DD-N lighting generally woke up earlier (+ 20 min), slept longer (week 1: + 11 min; week 2: + 27 min) and showed higher sleep efficiency (+ 2.4%) and shorter periods of nighttime awakenings (- 15 min). In the second treatment week, patients started sleep and the most active 10-h period earlier (- 33 min and - 64 min, respectively). This pilot study gives first evidence that depressed patients' sleep and circadian rest/activity system may benefit from bedroom lighting when starting inpatient treatment.
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