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Collery A, Browne JA, O'Brien C, Sheridan JT, Murphy BA. Optimised Stable Lighting Strengthens Circadian Clock Gene Rhythmicity in Equine Hair Follicles. Animals (Basel) 2023; 13:2335. [PMID: 37508112 PMCID: PMC10376498 DOI: 10.3390/ani13142335] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Hair follicles (HF) represent a useful tissue for monitoring the circadian clock in mammals. Irregular light exposure causes circadian disruption and represents a welfare concern for stabled horses. We aimed to evaluate the impact of two stable lighting regimes on circadian clock gene rhythmicity in HF from racehorses. Two groups of five Thoroughbred racehorses in training at a commercial racehorse yard were exposed to standard incandescent light or a customized LED lighting system. The control group received light from incandescent bulbs used according to standard yard practice. The treatment group received timed, blue-enriched white LED light by day and dim red LED light at night. On weeks 0 and 20, mane hairs were collected at 4 h intervals for 24 h. Samples were stored in RNAlater at -20 °C. RNA was isolated and samples interrogated by quantitative PCR for the core clock genes: ARNTL, CRY1, PER1, PER2, NR1D2, and the clock-controlled gene DBP. Cosinor analyses revealed 24 h rhythmicity for NR1D2 and PER2 and approached significance for CRY1 (p = 0.013, p = 0.013, and p = 0.051, respectively) in week 20 in the treatment group only. No rhythmicity was detected in week 0 or in week 20 in the HF of control horses. Results suggest that lighting practices in racehorse stables may be improved to better stimulate optimum functioning of the circadian system.
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Affiliation(s)
- Aileen Collery
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland
| | - John A Browne
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland
| | | | - John T Sheridan
- School of Electrical, Electronic and Mechanical Engineering, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland
| | - Barbara A Murphy
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland
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2
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Baptista E, André Arriel R, de Castro Carvalho AL, Bispo MMC, Rodrigues AB, Souza H, Mota GR, Marocolo M. Influence of Wearing Blue Lenses on Melatonin Production and
Performance in Volleyball Players. Sports Med Int Open 2022; 6:E1-E8. [PMID: 35211651 PMCID: PMC8860502 DOI: 10.1055/a-1720-6083] [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: 08/16/2021] [Accepted: 12/05/2021] [Indexed: 11/29/2022] Open
Abstract
We analyzed the effects of wearing blue lenses on melatonin level, physical and
cognitive performance. Fifteen youth volleyball players
(15.0±1.5 yrs) attended the laboratory on 3 occasions (48-h
interval): on the 1
st
visit they were familiarized with the
procedures of the study, and on 2
nd
and 3
rd
visits they
were submitted to the testing protocol wearing transparent (control) or blue
lens glasses in a counterbalanced crossover design. The protocol consisted of
10 min in “total darkness,” 30 min of light
stimulation (wearing blue or transparent lenses), followed by an attentional
test, and an agility T-test (without wearing the glasses). Samples of saliva (to
determine melatonin concentration) were obtained pre- and post-exposure
(30 min) to artificial light, wearing the lenses. Sleepiness, alertness,
attention, mood, and perceived recovery status and performance variables
(reaction time and T-test) were assessed after lens exposure. Melatonin levels
did not differ within and between groups (blue lenses, pre: 0.79±0.73
and post: 1.19±1.374 pg/dl, p=0.252, effect size
(ES)=0.38; control, pre: 0.97±1.00 and post:
0.67±0.71 pg/dl, p=0.305,
ES=–0.35). Nonetheless, melatonin differences were significantly
correlated with physical sedation for glasses with blue lenses
(r=−0.526; p=0.04). No other variables differed
(p>0.05) between protocols, including T-test performance
(p=0.07; ES=0.41). Blue lenses do not influence melatonin
levels, cognitive/physical performance, and mood status in amateur youth
volleyball players.
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Affiliation(s)
- Eduardo Baptista
- Institute of Biological Sciences, Department of Physiology,
Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Rhai André Arriel
- Institute of Biological Sciences, Department of Physiology,
Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Ana Luiza de Castro Carvalho
- Institute of Biological Sciences, Department of Physiology,
Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Matheus M. C. Bispo
- Institute of Biological Sciences, Department of Physiology,
Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Alex Batista Rodrigues
- Institute of Biological Sciences, Department of Physiology,
Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Hiago Souza
- Institute of Biological Sciences, Department of Physiology,
Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Gustavo R. Mota
- Department of Sport Sciences/Institute of Health Sciences,
Federal University of Triangulo Mineiro, UBERABA, Brazil
| | - Moacir Marocolo
- Institute of Biological Sciences, Department of Physiology,
Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
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3
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Hayano J, Ueda N, Kisohara M, Yoshida Y, Yuda E. Ambient-task combined lighting to regulate autonomic and psychomotor arousal levels without compromising subjective comfort to lighting. J Physiol Anthropol 2021; 40:8. [PMID: 34372917 PMCID: PMC8353805 DOI: 10.1186/s40101-021-00258-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 07/26/2021] [Indexed: 01/18/2023] Open
Abstract
Background Although evidence of both beneficial and adverse biological effects of lighting has accumulated, biologically favorable lighting often does not match subjectively comfortable lighting. By controlling the correlated color temperature (CCT) of ambient lights, we investigated the feasibility of combined lighting that meets both biological requirements and subjective comfort. Methods Two types of combined lightings were compared; one consisted of a high-CCT (12000 K) light-emitting diode (LED) panel as the ambient light and a low-CCT (5000 K) LED stand light as the task light (high-low combined lighting), and the other consisted of a low-CCT (4500 K) LED panel as the ambient light and the same low-CCT (5000 K) stand light as the task light (low-low combined lighting) as control. Ten healthy subjects (5 young and 5 elderly) were exposed to the two types of lighting on separate days. Autonomic function by heart rate variability, psychomotor performances, and subjective comfort were compared. Results Both at sitting rest and during psychomotor workload, heart rate was higher and the parasympathetic index of heart rate variability was lower under the high-low combined lighting than the low-low combined lighting in both young and elderly subject groups. Increased psychomotor alertness in the elderly and improved sustainability of concentration work performance in both age groups were also observed under the high-low combined lighting. However, no significant difference was observed in the visual-analog-scale assessment of subjective comfort between the two types of lightings. Conclusions High-CCT ambient lighting, even when used in combination with low-CCT task lighting, could increase autonomic and psychomotor arousal levels without compromising subjective comfort. This finding suggests the feasibility of independent control of ambient and task lighting as a way to achieve both biological function regulation and subjective comfort.
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Affiliation(s)
- Junichiro Hayano
- Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya, 467-8601, Japan.
| | - Norihiro Ueda
- Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya, 467-8601, Japan
| | - Masaya Kisohara
- Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya, 467-8601, Japan
| | - Yutaka Yoshida
- Nagoya City University Graduate School of Design and Architecture, Nagoya, 464-0083, Japan
| | - Emi Yuda
- Center for Data-driven Science and Artificial Intelligence, Tohoku University, 41 Kawauchi, Aoba-ku, Sendai, 980-8576, Japan
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4
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Abstract
In this highly digitalized era, sleep disorders are becoming more common and are associated with an increased burden of chronic disease. Shift workers are at an increased risk for both sleep disorders and metabolic syndrome. In this article, the authors outline the connection between circadian discordance, hormonal imbalance, and the development of metabolic syndrome in shift workers. Based on a literature review of animal model studies, observational studies, and clinical trials conducted between August and October of 2018, the authors offer several clinical interventions, including work schedules, light therapy, medications, and dietary habits to improve the circadian synchronicity of shift workers and reduce their risk of morbidity and mortality. It is important for physicians to be familiar with the consequences of shift work and ways to mitigate the risks for this patient population.
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5
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Lee SI, Kinoshita S, Noguchi A, Eto T, Ohashi M, Nishimura Y, Maeda K, Motomura Y, Awata Y, Higuchi S. Melatonin suppression during a simulated night shift in medium intensity light is increased by 10-minute breaks in dim light and decreased by 10-minute breaks in bright light. Chronobiol Int 2020; 37:897-909. [PMID: 32326827 DOI: 10.1080/07420528.2020.1752704] [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: 01/07/2023]
Abstract
Exposure to light at night results in disruption of endogenous circadian rhythmicity and/or suppression of pineal melatonin, which can consequently lead to acute or chronic adverse health problems. In the present study, we investigated whether exposure to very dim light or very bright light for a short duration influences melatonin suppression, subjective sleepiness, and performance during exposure to constant moderately bright light. Twenty-four healthy male university students were divided into two experimental groups: Half of them (mean age: 20.0 ± 0.9 years) participated in an experiment for short-duration (10 min) light conditions of medium intensity light (430 lx, medium breaks) vs. very dim light (< 1 lx, dim breaks) and the other half (mean age: 21.3 ± 2.5 years) participated in an experiment for short-duration light conditions of medium intensity light (430 lx, medium breaks) vs. very bright light (4700 lx, bright breaks). Each simulated night shift consisting of 5 sets (each including 50-minute night work and 10-minute break) was performed from 01:00 to 06:00 h. The subjects were exposed to medium intensity light (550 lx) during the night work. Each 10-minute break was conducted every hour from 02:00 to 06:00 h. Salivary melatonin concentrations were measured, subjective sleepiness was assessed, the psychomotor vigilance task was performed at hourly intervals from 21:00 h until the end of the experiment. Compared to melatonin suppression between 04:00 and 06:00 h in the condition of medium breaks, the condition of dim breaks significantly promoted melatonin suppression and the condition of bright breaks significantly diminished melatonin suppression. However, there was no remarkable effect of either dim breaks or bright breaks on subjective sleepiness and performance of the psychomotor vigilance task. Our findings suggest that periodic exposure to light for short durations during exposure to a constant light environment affects the sensitivity of pineal melatonin to constant light depending on the difference between light intensities in the two light conditions (i.e., short light exposure vs. constant light exposure). Also, our findings indicate that exposure to light of various intensities at night could be a factor influencing the light-induced melatonin suppression in real night work settings.
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Affiliation(s)
- Sang-Il Lee
- Department of Human Science, Faculty of Design, Kyushu University , Fukuoka, Japan.,Division of Human Environmental Systems, Faculty of Engineering, Hokkaido University , Sapporo, Japan
| | - Saki Kinoshita
- Department of Kansei Science, Graduate School of Integrated Frontier Science, Kyushu University , Fukuoka, Japan
| | - Anna Noguchi
- Department of Kansei Science, Graduate School of Integrated Frontier Science, Kyushu University , Fukuoka, Japan
| | - Taisuke Eto
- Department of Kansei Science, Graduate School of Integrated Frontier Science, Kyushu University , Fukuoka, Japan
| | - Michihiro Ohashi
- Department of Kansei Science, Graduate School of Integrated Frontier Science, Kyushu University , Fukuoka, Japan
| | - Yuki Nishimura
- Department of Kansei Science, Graduate School of Integrated Frontier Science, Kyushu University , Fukuoka, Japan.,Occupational Stress and Health Management Research Group, National Institute of Occupational Safety and Health , Kawasaki, Japan
| | - Kaho Maeda
- Ground Facilities Department, Japan Aerospace Exploration Agency , Tsukuba, Japan
| | - Yuki Motomura
- Department of Human Science, Faculty of Design, Kyushu University , Fukuoka, Japan
| | - Yasuhiro Awata
- Ground Facilities Department, Japan Aerospace Exploration Agency , Tsukuba, Japan
| | - Shigekazu Higuchi
- Department of Human Science, Faculty of Design, Kyushu University , Fukuoka, Japan
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6
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Abstract
Artificial light at night (ALAN) is increasing exponentially worldwide, accelerated by the transition to new efficient lighting technologies. However, ALAN and resulting light pollution can cause unintended physiological consequences. In vertebrates, production of melatonin—the “hormone of darkness” and a key player in circadian regulation—can be suppressed by ALAN. In this paper, we provide an overview of research on melatonin and ALAN in vertebrates. We discuss how ALAN disrupts natural photic environments, its effect on melatonin and circadian rhythms, and different photoreceptor systems across vertebrate taxa. We then present the results of a systematic review in which we identified studies on melatonin under typical light-polluted conditions in fishes, amphibians, reptiles, birds, and mammals, including humans. Melatonin is suppressed by extremely low light intensities in many vertebrates, ranging from 0.01–0.03 lx for fishes and rodents to 6 lx for sensitive humans. Even lower, wavelength-dependent intensities are implied by some studies and require rigorous testing in ecological contexts. In many studies, melatonin suppression occurs at the minimum light levels tested, and, in better-studied groups, melatonin suppression is reported to occur at lower light levels. We identify major research gaps and conclude that, for most groups, crucial information is lacking. No studies were identified for amphibians and reptiles and long-term impacts of low-level ALAN exposure are unknown. Given the high sensitivity of vertebrate melatonin production to ALAN and the paucity of available information, it is crucial to research impacts of ALAN further in order to inform effective mitigation strategies for human health and the wellbeing and fitness of vertebrates in natural ecosystems.
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7
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Katsuura T, Lee S. A review of the studies on nonvisual lighting effects in the field of physiological anthropology. J Physiol Anthropol 2019; 38:2. [PMID: 30670097 PMCID: PMC6343353 DOI: 10.1186/s40101-018-0190-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/04/2018] [Indexed: 12/16/2022] Open
Abstract
Here, we review the history and the trends in the research on the nonvisual effect of light in the field of physiological anthropology. Research on the nonvisual effect of light in the field of physiological anthropology was pioneered by Sato and colleagues in the early 1990s. These authors found that the color temperature of light affected physiological functions in humans. The groundbreaking event with regard to the study of nonvisual effects of light was the discovery of the intrinsically photosensitive retinal ganglion cells in the mammalian retina in the early 2000s. The interest of the physiological anthropology scientific community in the nonvisual effects of light has been increasing since then. A total of 61 papers on nonvisual effects of light were published in the Journal of Physiological Anthropology (including its predecessor journals) until October 2018, 14 papers (1.4/year) in the decade from 1992 to 2001, 45 papers (2.8/year) in the 16 years between 2002 and 2017, and two papers in 2018 (January-October). The number of papers on this topic has been increasing in recent years. We categorized all papers according to light conditions, such as color temperature of light, light intensity, and monochromatic light. Among the 61 papers, 11 papers were related to color temperature, 20 papers were related to light intensity, 18 papers were related to monochromatic light, and 12 papers were classified as others. We provide an overview of these papers and mention future research prospects.
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Affiliation(s)
- Tetsuo Katsuura
- Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
| | - Soomin Lee
- Center for Environment, Health and Sciences, Chiba University, 6-2-1 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
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8
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Schmidt C, Xhrouet M, Hamacher M, Delloye E, LeGoff C, Cavalier E, Collette F, Vandewalle G. Light exposure via a head-mounted device suppresses melatonin and improves vigilant attention without affecting cortisol and comfort. Psych J 2018; 7:163-175. [PMID: 29943899 DOI: 10.1002/pchj.215] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 04/03/2018] [Accepted: 04/08/2018] [Indexed: 11/11/2022]
Abstract
We aimed at assessing whether a head-mounted light therapy device, enriched in blue wavelengths, suppresses melatonin secretion and improves vigilant attention in the late evening hours. We also assessed whether using such light device is associated with discomfort and physiological stress. Seventeen healthy young participants (eight females) participated in a counterbalanced within-subject design during which they were exposed for 2 hr before habitual sleep time to a blue-enriched light (1500 lx) or to a lower intensity red-light (150 lx) control condition, using a new-generation light emitting diode (LED) head-mounted device. Compared to the red light control condition, blue-enriched light significantly reduced melatonin secretion and reaction times during a psychomotor vigilance task while no significant differences were detected in discomfort and cortisol levels. These results suggest that, compared to a control condition, blue-enriched light, delivered by a new-generation head-mounted device, elicits typical non-visual responses to light without detectable discomfort and physiological stress. They suggest that such devices might constitute an effective alternative to standard light boxes.
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Affiliation(s)
- Christina Schmidt
- Sleep Research Group, GIGA-Institute, Cyclotron Research Centre-In Vivo Imaging Unit, University of Liège, Liège, Belgium.,Psychology and Neuroscience of Cognition Research Unit (PsyNCog), Faculty of Psychology and Educational Sciences, University of Liège, Liège, Belgium
| | - Marine Xhrouet
- Sleep Research Group, GIGA-Institute, Cyclotron Research Centre-In Vivo Imaging Unit, University of Liège, Liège, Belgium.,Psychology and Neuroscience of Cognition Research Unit (PsyNCog), Faculty of Psychology and Educational Sciences, University of Liège, Liège, Belgium
| | - Manon Hamacher
- Sleep Research Group, GIGA-Institute, Cyclotron Research Centre-In Vivo Imaging Unit, University of Liège, Liège, Belgium.,Psychology and Neuroscience of Cognition Research Unit (PsyNCog), Faculty of Psychology and Educational Sciences, University of Liège, Liège, Belgium
| | | | - Caroline LeGoff
- Department of Clinical Chemistry, University Hospital of Liège, University of Liège, Liège, Belgium
| | - Etienne Cavalier
- Department of Clinical Chemistry, University Hospital of Liège, University of Liège, Liège, Belgium
| | - Fabienne Collette
- Sleep Research Group, GIGA-Institute, Cyclotron Research Centre-In Vivo Imaging Unit, University of Liège, Liège, Belgium.,Psychology and Neuroscience of Cognition Research Unit (PsyNCog), Faculty of Psychology and Educational Sciences, University of Liège, Liège, Belgium
| | - Gilles Vandewalle
- Sleep Research Group, GIGA-Institute, Cyclotron Research Centre-In Vivo Imaging Unit, University of Liège, Liège, Belgium
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9
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Souman JL, Tinga AM, te Pas SF, van Ee R, Vlaskamp BN. Acute alerting effects of light: A systematic literature review. Behav Brain Res 2018; 337:228-239. [DOI: 10.1016/j.bbr.2017.09.016] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/01/2017] [Accepted: 09/07/2017] [Indexed: 10/18/2022]
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10
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Nagashima S, Osawa M, Matsuyama H, Ohoka W, Ahn A, Wakamura T. Bright-light exposure during daytime sleeping affects nocturnal melatonin secretion after simulated night work. Chronobiol Int 2017; 35:229-239. [PMID: 29144169 DOI: 10.1080/07420528.2017.1394321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The guidelines for night and shift workers recommend that after night work, they should sleep in a dark environment during the daytime. However, staying in a dark environment during the daytime reduces nocturnal melatonin secretion and delays its onset. Daytime bright-light exposure after night work is important for melatonin synthesis the subsequent night and for maintaining the circadian rhythms. However, it is not clear whether daytime sleeping after night work should be in a dim- or a bright-light environment for maintaining melatonin secretion. The aim of this study, therefore, was to evaluate the effect of bright-light exposure during daytime sleeping on nocturnal melatonin secretion after simulated night work. Twelve healthy male subjects, aged 24.8 ± 4.6 (mean ± SD), participated in 3-day sessions under two experimental conditions, bright light or dim light, in a random order. On the first day, the subjects entered the experimental room at 16:00 and saliva samples were collected every hour between 18:00 and 00:00 under dim-light conditions. Between 00:00 and 08:00, they participated in tasks that simulated night work. At 10:00 the next morning, they slept for 6 hours under either a bright-light condition (>3000 lx) or a dim-light condition (<50 lx). In the evening, saliva samples were collected as on the first day. The saliva samples were analyzed for melatonin concentration. Activity and sleep times were recorded by a wrist device worn throughout the experiment. In the statistical analysis, the time courses of melatonin concentration were compared between the two conditions by three-way repeated measurements ANOVA (light condition, day and time of day). The change in dim light melatonin onset (ΔDLMO) between the first and second days, and daytime and nocturnal sleep parameters after the simulated night work were compared between the light conditions using paired t-tests. The ANOVA results indicated a significant interaction (light condition and3 day) (p = .006). Post hoc tests indicated that in the dim-light condition, the melatonin concentration was significantly lower on the second day than on the first day (p = .046); however, in the bright-light condition, there was no significant difference in the melatonin concentration between the days (p = .560). There was a significant difference in ΔDLMO between the conditions (p = .015): DLMO after sleeping was advanced by 11.1 ± 17.4 min under bright-light conditions but delayed for 7.2 ± 13.6 min after sleeping under dim-light conditions. No significant differences were found in any sleep parameter. Our study demonstrated that daytime sleeping under bright-light conditions after night work could not reduce late evening melatonin secretion until midnight or delay the phase of melatonin secretion without decreasing the quality of the daytime sleeping. Thus, these results suggested that, to enhance melatonin secretion and to maintain their conventional sleep-wake cycle, after night work, shift workers should sleep during the daytime under bright-light conditions rather than dim-light conditions.
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Affiliation(s)
- Shunsuke Nagashima
- a Kyoto university , Department of Human Health Sciences, Graduate school of Medicine , Kyoto , Japan.,b Research fellow of Japan Society for the Promotion of Science , Tokyo , Japan
| | - Madoka Osawa
- c Department of Human Health Sciences, Faculty of Medicine , Kyoto University , Kyoto , Japan
| | - Hiroto Matsuyama
- c Department of Human Health Sciences, Faculty of Medicine , Kyoto University , Kyoto , Japan
| | - Wataru Ohoka
- c Department of Human Health Sciences, Faculty of Medicine , Kyoto University , Kyoto , Japan
| | - Aemi Ahn
- c Department of Human Health Sciences, Faculty of Medicine , Kyoto University , Kyoto , Japan
| | - Tomoko Wakamura
- a Kyoto university , Department of Human Health Sciences, Graduate school of Medicine , Kyoto , Japan
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11
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Slanger TE, Gross JV, Pinger A, Morfeld P, Bellinger M, Duhme A, Reichardt Ortega RA, Costa G, Driscoll TR, Foster RG, Fritschi L, Sallinen M, Liira J, Erren TC. Person-directed, non-pharmacological interventions for sleepiness at work and sleep disturbances caused by shift work. Cochrane Database Syst Rev 2016; 2016:CD010641. [PMID: 27549931 PMCID: PMC8406755 DOI: 10.1002/14651858.cd010641.pub2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Shift work is often associated with sleepiness and sleep disorders. Person-directed, non-pharmacological interventions may positively influence the impact of shift work on sleep, thereby improving workers' well-being, safety, and health. OBJECTIVES To assess the effects of person-directed, non-pharmacological interventions for reducing sleepiness at work and improving the length and quality of sleep between shifts for shift workers. SEARCH METHODS We searched CENTRAL, MEDLINE Ovid, Embase, Web of Knowledge, ProQuest, PsycINFO, OpenGrey, and OSH-UPDATE from inception to August 2015. We also screened reference lists and conference proceedings and searched the World Health Organization (WHO) Trial register. We contacted experts to obtain unpublished data. SELECTION CRITERIA Randomised controlled trials (RCTs) (including cross-over designs) that investigated the effect of any person-directed, non-pharmacological intervention on sleepiness on-shift or sleep length and sleep quality off-shift in shift workers who also work nights. DATA COLLECTION AND ANALYSIS At least two authors screened titles and abstracts for relevant studies, extracted data, and assessed risk of bias. We contacted authors to obtain missing information. We conducted meta-analyses when pooling of studies was possible. MAIN RESULTS We included 17 relevant trials (with 556 review-relevant participants) which we categorised into three types of interventions: (1) various exposures to bright light (n = 10); (2) various opportunities for napping (n = 4); and (3) other interventions, such as physical exercise or sleep education (n = 3). In most instances, the studies were too heterogeneous to pool. Most of the comparisons yielded low to very low quality evidence. Only one comparison provided moderate quality evidence. Overall, the included studies' results were inconclusive. We present the results regarding sleepiness below. Bright light Combining two comparable studies (with 184 participants altogether) that investigated the effect of bright light during the night on sleepiness during a shift, revealed a mean reduction 0.83 score points of sleepiness (measured via the Stanford Sleepiness Scale (SSS) (95% confidence interval (CI) -1.3 to -0.36, very low quality evidence). Another trial did not find a significant difference in overall sleepiness on another sleepiness scale (16 participants, low quality evidence).Bright light during the night plus sunglasses at dawn did not significantly influence sleepiness compared to normal light (1 study, 17 participants, assessment via reaction time, very low quality evidence).Bright light during the day shift did not significantly reduce sleepiness during the day compared to normal light (1 trial, 61 participants, subjective assessment, low quality evidence) or compared to normal light plus placebo capsule (1 trial, 12 participants, assessment via reaction time, very low quality evidence). Napping during the night shiftA meta-analysis on a single nap opportunity and the effect on the mean reaction time as a surrogate for sleepiness, resulted in a 11.87 ms reduction (95% CI 31.94 to -8.2, very low quality evidence). Two other studies also reported statistically non-significant decreases in reaction time (1 study seven participants; 1 study 49 participants, very low quality evidence).A two-nap opportunity resulted in a statistically non-significant increase of sleepiness (subjective assessment) in one study (mean difference (MD) 2.32, 95% CI -24.74 to 29.38, 1 study, 15 participants, low quality evidence). Other interventionsPhysical exercise and sleep education interventions showed promise, but sufficient data to draw conclusions are lacking. AUTHORS' CONCLUSIONS Given the methodological diversity of the included studies, in terms of interventions, settings, and assessment tools, their limited reporting and the very low to low quality of the evidence they present, it is not possible to determine whether shift workers' sleepiness can be reduced or if their sleep length or quality can be improved with these interventions.We need better and adequately powered RCTs of the effect of bright light, and naps, either on their own or together and other non-pharmacological interventions that also consider shift workers' chronobiology on the investigated sleep parameters.
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Affiliation(s)
- Tracy E Slanger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - J. Valérie Gross
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Andreas Pinger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Peter Morfeld
- Evonik Technology & Infrastructure GmbHInstitute for Occupational Epidemiology and Risk Assessment (IERA)Rellinghauser Str. 1‐11EssenGermany45128
| | - Miriam Bellinger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Anna‐Lena Duhme
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Rosalinde Amancay Reichardt Ortega
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Giovanni Costa
- University of MilanDepartment of Clinical Sciences and Community HealthVia S. Barnaba 8MilanItaly20122
| | - Tim R Driscoll
- The University of SydneySchool of Public HealthEdward Ford Building (A27)SydneyNew South WalesAustralia2006
| | - Russell G Foster
- University of OxfordNuffield Department of Clinical Neurosciences; Circadian and Visual NeuroscienceLevel 6, West Wing, The John Radcliffe HospitalHeadley WayOxfordUKOX3 9DU
| | - Lin Fritschi
- Curtin UniversitySchool of Public Health35 Stirling HighwayPerthWest AustraliaAustralia6152
| | - Mikael Sallinen
- Finnish Institute of Occupational HealthCentre of Expertise for the Development of Work and Organizations / Working Hours, Alertness, and Professional Traffic teamTopeliuksenkatu 41 a AHelsinkiFinlandFI‐00250
| | - Juha Liira
- Finnish Institute of Occupational HealthResearch and Development in Occupational Health ServicesTopeliuksenkatu 41 a AHelsinkiFinlandFI‐00250
| | - Thomas C Erren
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
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Nogueira LM, Sampson JN, Chu LW, Yu K, Andriole G, Church T, Stanczyk FZ, Koshiol J, Hsing AW. Individual variations in serum melatonin levels through time: implications for epidemiologic studies. PLoS One 2013; 8:e83208. [PMID: 24376664 PMCID: PMC3871612 DOI: 10.1371/journal.pone.0083208] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 11/11/2013] [Indexed: 12/14/2022] Open
Abstract
Melatonin, a marker for the circadian rhythm with serum levels peaking between 2AM and 5AM, is hypothesized to possess anti-cancer properties, making it a mechanistic candidate for the probable carcinogenic effect of circadian rhythm disruption. In order to weigh epidemiologic evidence on the association of melatonin with cancer, we must first understand the laboratory and biological sources of variability in melatonin levels measured in samples. Participants for this methodological study were men enrolled in the Prostate Lung Colorectal and Ovarian Cancer Screening Trial (PLCO). We measured serum melatonin levels over a five year period in 97 individuals to test if melatonin levels are steady over time. The Pearson correlation coefficient between two measures separated by 1 year was 0.87, while the correlation between two measures separated by 5 years was to 0.70. In an additional cross-sectional study of 292 individuals, we used Analysis of Variance to identify differences in melatonin levels between different lifestyle and environmental characteristics. Serum melatonin levels were slightly higher in samples collected from 130 individuals during the winter, (6.36±0.59 pg/ml) than in samples collected from 119 individuals during the summer (4.83±0.62 pg/ml). Serum melatonin levels were lowest in current smokers (3.02±1.25 pg/ml, p = 0.007) compared to never (6.66±0.66 pg/ml) and former (5.59±0.50 pg/ml) smokers whereas BMI did not significantly affect serum melatonin levels in this study. In conclusion, the high 5 year correlation of melatonin levels implies that single measurements may be used to detect population level associations between melatonin and risk of cancer. Furthermore, our results reiterate the need to record season of sample collection, and individual characteristics in order to maximize study power and prevent confounding.
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Affiliation(s)
- Leticia M. Nogueira
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, United States of America
- * E-mail:
| | - Joshua N. Sampson
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Lisa W. Chu
- Cancer Prevention Institute of California, Fremont, California, United States of America
| | - Kai Yu
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Gerald Andriole
- Division of Urological Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Timothy Church
- Department of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, Minnesota, United States of America
| | - Frank Z. Stanczyk
- Department of Obstetrics, Gynecology, and Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jill Koshiol
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Ann W. Hsing
- Cancer Prevention Institute of California, Fremont, California, United States of America
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Liebrich LS, Schredl M, Findeisen P, Groden C, Bumb JM, Nölte IS. Morphology and function: MR pineal volume and melatonin level in human saliva are correlated. J Magn Reson Imaging 2013; 40:966-71. [PMID: 24214660 DOI: 10.1002/jmri.24449] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 09/10/2013] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate the relation between circadian saliva melatonin levels and pineal volume as determined by MRI. Plasma melatonin levels follow a circadian rhythm with a high interindividual variability. MATERIALS AND METHODS In 103 healthy individuals saliva melatonin levels were determined at four time points within 24 h and MRI was performed once (3.0 Tesla, including three-dimensional T2 turbo spin echo [3D-T2-TSE], susceptibility-weighted imaging [SWI]). Pineal volume as well as cyst volume were assessed from multiplanar reconstructed 3D-T2-TSE images. Pineal calcification volume tissue was determined on SWI. To correct for hormonal inactive pineal tissue, cystic and calcified areas were excluded. Sleep quality was assessed with the Landeck Inventory for sleep quality disturbance. RESULTS Solid and uncalcified pineal volume correlated to melatonin maximum (r = 0.28; P < 0.05) and area under the curve (r = 0.29; P < 0.05). Of interest, solid and uncalcified pineal volume correlated negatively with the sleep rhythm disturbances subscore (r = -0.17; P < 0.05) despite a very homogenous population. CONCLUSION Uncalcified solid pineal tissue measured by 3D-T2-TSE and SWI is related to human saliva melatonin levels. The analysis of the sleep quality and pineal volume suggests a linkage between better sleep quality and hormonal active pineal tissue.
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Affiliation(s)
- Luisa-Sophie Liebrich
- Department of Neuroradiology, Medical Faculty Mannheim, University of Heidelberg, Germany
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Association between melanopsin gene polymorphism (I394T) and pupillary light reflex is dependent on light wavelength. J Physiol Anthropol 2013; 32:16. [PMID: 24119231 PMCID: PMC4015917 DOI: 10.1186/1880-6805-32-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 09/30/2013] [Indexed: 12/17/2022] Open
Abstract
Background Our aim was to determine the association between melanopsin gene polymorphism and pupillary light reflex under diverse photic conditions, including different intensities and wavelengths. Methods A total of 195 visually corrected subjects volunteered for investigation of the melanopsin gene of single nucleotide polymorphism (SNP) of rs1079610 (I394T). The genotype groups were TT (n = 126), TC (n = 55), and CC (n = 8), and 75 of the subjects, including subjects with TT (n = 34), TC (n = 33), and CC (n = 8) participated in our experiment. Three monochromatic lights with peak wavelengths of 465 nm (blue), 536 nm (green), and 632 nm (red) were prepared, and each light was projected to the subjects with five intensities, 12, 13, 14, 14.5 and 15 log photons/(cm2 s), for one minute. The pupil size of the left eye was measured under each light condition after a 1-minute adaptation. Results The pupils of the TC + CC genotypes (n = 38) were significantly smaller than those of the TT genotype (n = 31) under a blue (463 nm) light condition with 15 log photons/(cm2 s) (P < 0.05). In contrast, there were no significant differences under green (536 nm) and red (632 nm) light conditions. Conversely, relative pupil constrictions of the TC + CC genotypes were greater than those of the TT genotype under both blue and green conditions with high intensities (14.5 and 15 log photons/(cm2 s)). In contrast, there were no significant differences between genotype groups in pupil size and relative pupilloconstriction under the red light conditions. Conclusions Our findings suggest that the melanopsin gene polymorphism (I394T) functionally interacts with pupillary light reflex, depending on light intensity and, particularly, wavelength, and that under a light condition fulfilling both high intensity and short wavelength, the pupillary light response of subjects with the C allele (TC + CC) is more sensitive to light than that of subjects with the TT genotype.
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