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Sletten TL, Sullivan JP, Arendt J, Palinkas LA, Barger LK, Fletcher L, Arnold M, Wallace J, Strauss C, Baker RJS, Kloza K, Kennaway DJ, Rajaratnam SMW, Ayton J, Lockley SW. The role of circadian phase in sleep and performance during Antarctic winter expeditions. J Pineal Res 2022; 73:e12817. [PMID: 35833316 PMCID: PMC9541096 DOI: 10.1111/jpi.12817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/23/2022] [Accepted: 07/06/2022] [Indexed: 11/29/2022]
Abstract
The Antarctic environment presents an extreme variation in the natural light-dark cycle which can cause variability in the alignment of the circadian pacemaker with the timing of sleep, causing sleep disruption, and impaired mood and performance. This study assessed the incidence of circadian misalignment and the consequences for sleep, cognition, and psychological health in 51 over-wintering Antarctic expeditioners (45.6 ± 11.9 years) who completed daily sleep diaries, and monthly performance tests and psychological health questionnaires for 6 months. Circadian phase was assessed via monthly 48-h urine collections to assess the 6-sulphatoxymelatonin (aMT6s) rhythm. Although the average individual sleep duration was 7.2 ± 0.8 h, there was substantial sleep deficiency with 41.4% of sleep episodes <7 h and 19.1% <6 h. Circadian phase was highly variable and 34/50 expeditioners had sleep episodes that occurred at an abnormal circadian phase (acrophase outside of the sleep episode), accounting for 18.8% (295/1565) of sleep episodes. Expeditioners slept significantly less when misaligned (6.1 ± 1.3 h), compared with when aligned (7.3 ± 1.0 h; p < .0001). Performance and mood were worse when awake closer to the aMT6s peak and with increased time awake (all p < .0005). This research highlights the high incidence of circadian misalignment in Antarctic over-wintering expeditioners. Similar incidence has been observed in long-duration space flight, reinforcing the fidelity of Antarctica as a space analog. Circadian misalignment has considerable safety implications, and potentially longer term health risks for other circadian-controlled physiological systems. This increased risk highlights the need for preventative interventions, such as proactively planned lighting solutions, to ensure circadian alignment during long-duration Antarctic and space missions.
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Affiliation(s)
- Tracey L. Sletten
- Turner Institute for Brain and Mental Health and School of Psychological SciencesMonash UniversityVictoriaAustralia
| | - Jason P. Sullivan
- Division of Sleep and Circadian Disorders, Departments of Medicine and NeurologyBrigham and Women's HospitalBostonMassachusettsUSA
| | - Josephine Arendt
- Faculty of Health and Medical SciencesUniversity of SurreyGuildfordSurreyUK
| | - Lawrence A. Palinkas
- Suzanne Dworak‐Peck School of Social WorkUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Laura K. Barger
- Turner Institute for Brain and Mental Health and School of Psychological SciencesMonash UniversityVictoriaAustralia
- Division of Sleep and Circadian Disorders, Departments of Medicine and NeurologyBrigham and Women's HospitalBostonMassachusettsUSA
- Division of Sleep Medicine, Harvard Medical SchoolBostonMassachusettsUSA
| | - Lloyd Fletcher
- Polar Medicine Unit, Australian Antarctic DivisionKingstonTasmaniaAustralia
| | - Malcolm Arnold
- Polar Medicine Unit, Australian Antarctic DivisionKingstonTasmaniaAustralia
| | - Jan Wallace
- Polar Medicine Unit, Australian Antarctic DivisionKingstonTasmaniaAustralia
| | - Clive Strauss
- Polar Medicine Unit, Australian Antarctic DivisionKingstonTasmaniaAustralia
| | | | - Kate Kloza
- Polar Medicine Unit, Australian Antarctic DivisionKingstonTasmaniaAustralia
| | - David J. Kennaway
- Robinson Research Institute, School of Medicine, Discipline of Obstetrics and GynaecologyUniversity of AdelaideAdelaideSouth AustraliaAustralia
| | - Shantha M. W. Rajaratnam
- Turner Institute for Brain and Mental Health and School of Psychological SciencesMonash UniversityVictoriaAustralia
- Division of Sleep and Circadian Disorders, Departments of Medicine and NeurologyBrigham and Women's HospitalBostonMassachusettsUSA
- Division of Sleep Medicine, Harvard Medical SchoolBostonMassachusettsUSA
| | - Jeff Ayton
- Polar Medicine Unit, Australian Antarctic DivisionKingstonTasmaniaAustralia
| | - Steven W. Lockley
- Division of Sleep and Circadian Disorders, Departments of Medicine and NeurologyBrigham and Women's HospitalBostonMassachusettsUSA
- Division of Sleep Medicine, Harvard Medical SchoolBostonMassachusettsUSA
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2
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Qian J, Morris CJ, Phillips AJK, Li P, Rahman SA, Wang W, Hu K, Arendt J, Czeisler CA, Scheer FAJL. Unanticipated daytime melatonin secretion on a simulated night shift schedule generates a distinctive 24-h melatonin rhythm with antiphasic daytime and nighttime peaks. J Pineal Res 2022; 72:e12791. [PMID: 35133678 PMCID: PMC8930611 DOI: 10.1111/jpi.12791] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 11/29/2022]
Abstract
The daily rhythm of plasma melatonin concentrations is typically unimodal, with one broad peak during the circadian night and near-undetectable levels during the circadian day. Light at night acutely suppresses melatonin secretion and phase shifts its endogenous circadian rhythm. In contrast, exposure to darkness during the circadian day has not generally been reported to increase circulating melatonin concentrations acutely. Here, in a highly-controlled simulated night shift protocol with 12-h inverted behavioral/environmental cycles, we unexpectedly found that circulating melatonin levels were significantly increased during daytime sleep (p < .0001). This resulted in a secondary melatonin peak during the circadian day in addition to the primary peak during the circadian night, when sleep occurred during the circadian day following an overnight shift. This distinctive diurnal melatonin rhythm with antiphasic peaks could not be readily anticipated from the behavioral/environmental factors in the protocol (e.g., light exposure, posture, diet, activity) or from current mathematical model simulations of circadian pacemaker output. The observation, therefore, challenges our current understanding of underlying physiological mechanisms that regulate melatonin secretion. Interestingly, the increase in melatonin concentration observed during daytime sleep was positively correlated with the change in timing of melatonin nighttime peak (p = .002), but not with the degree of light-induced melatonin suppression during nighttime wakefulness (p = .92). Both the increase in daytime melatonin concentrations and the change in the timing of the nighttime peak became larger after repeated exposure to simulated night shifts (p = .002 and p = .006, respectively). Furthermore, we found that melatonin secretion during daytime sleep was positively associated with an increase in 24-h glucose and insulin levels during the night shift protocol (p = .014 and p = .027, respectively). Future studies are needed to elucidate the key factor(s) driving the unexpected daytime melatonin secretion and the melatonin rhythm with antiphasic peaks during shifted sleep/wake schedules, the underlying mechanisms of their relationship with glucose metabolism, and the relevance for diabetes risk among shift workers.
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Affiliation(s)
- Jingyi Qian
- Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
| | - Christopher J Morris
- Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
| | - Andrew JK Phillips
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Peng Li
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
- Medical Biodynamics Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
| | - Shadab A Rahman
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
| | - Wei Wang
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
| | - Kun Hu
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
- Medical Biodynamics Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
| | - Josephine Arendt
- School of Biological Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Charles A Czeisler
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
| | - Frank AJL Scheer
- Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep and Circadian Disorders, Depts. Of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA 02115, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, United States
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Brown TM, Thapan K, Arendt J, Revell VL, Skene DJ. S-cone contribution to the acute melatonin suppression response in humans. J Pineal Res 2021; 71:e12719. [PMID: 33512714 DOI: 10.1111/jpi.12719] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 01/06/2023]
Abstract
Light influences diverse aspects of human physiology and behaviour including neuroendocrine function, the circadian system and sleep. A role for melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) in driving such effects is well established. However, rod and/or cone signals routed through ipRGCs could also influence "non-visual" spectral sensitivity. In humans, this has been most extensively studied for acute, light-dependent, suppression of nocturnal melatonin production. Of the published action spectra for melatonin suppression, one demonstrates a spectral sensitivity consistent with that expected for melanopsin while our own (using briefer 30 minute light exposures) displays very high sensitivity to short wavelength light, suggesting a contribution of S-cones. To clarify that possibility, six healthy young male participants were each exposed to 30 minutes of five irradiances of 415 nm monochromatic light (1-40 µW/cm2 ) across different nights. These data were then combined with the original action spectrum. The aggregated data are incompatible with the involvement of any single-opsin and multi-opsin models based on the original action spectrum (including Circadian Stimulus) fail to predict the responses to 415 nm stimuli. Instead, the extended action spectrum can be most simply approximated by an ~2:1 combination of melanopsin and S-cone signals. Such a model also better describes the magnitude of melatonin suppression observed in other studies using an equivalent 30 minute mono- or polychromatic light paradigm but not those using longer (90 minute) light exposures. In sum, these data provide evidence for an initial S-cone contribution to melatonin suppression that rapidly decays under extended light exposure.
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Affiliation(s)
- Timothy M Brown
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Kavita Thapan
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Josephine Arendt
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Victoria L Revell
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
- Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XP, UK
| | - Debra J Skene
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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Ruiz FS, Beijamini F, Beale AD, Gonçalves BDSB, Vartanian D, Taporoski TP, Middleton B, Krieger JE, Vallada H, Arendt J, Pereira AC, Knutson KL, Pedrazzoli M, von Schantz M. Early chronotype with advanced activity rhythms and dim light melatonin onset in a rural population. J Pineal Res 2020; 69:e12675. [PMID: 32598502 PMCID: PMC7508839 DOI: 10.1111/jpi.12675] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/11/2020] [Accepted: 06/18/2020] [Indexed: 11/28/2022]
Abstract
Studying communities at different stages of urbanisation and industrialisation can teach us how timing and intensity of light affect the circadian clock under real-life conditions. We have previously described a strong tendency towards morningness in the Baependi Heart Study, located in a small rural town in Brazil. Here, we tested the hypothesis that this morningness tendency is associated with early circadian phase based on objective measurements (as determined by dim light melatonin onset, DLMO, and activity) and light exposure. We also analysed how well the previously collected chronotype questionnaire data were able to predict these DLMO values. The average DLMO observed in 73 participants (40 female) was 20:03 ± 01:21, SD, with an earlier average onset in men (19:38 ± 01:16) than in women (20:24 ± 01:21; P ≤ .01). However, men presented larger phase angle between DLMO and sleep onset time as measured by actigraphy (4.11 hours vs 3.16 hours; P ≤ .01). Correlational analysis indicated associations between light exposure, activity rhythms and DLMO, such that early DLMO was observed in participants with higher exposure to light, higher activity and earlier light exposure. The strongest significant predictor of DLMO was morningness-eveningness questionnaire (MEQ) (beta=-0.35, P ≤ .05), followed by age (beta = -0.47, P ≤ .01). Sex, light exposure and variables derived from the Munich chronotype questionnaire were not significant predictors. Our observations demonstrate that both early sleep patterns and earlier circadian phase have been retained in this small rural town in spite of availability of electrification, in contrast to metropolitan postindustrial areas.
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Affiliation(s)
- Francieli S. Ruiz
- Department of Psychiatry, University of São Paulo School of Medicine, São Paulo, SP, Brazil
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Felipe Beijamini
- Department of Psychiatry, University of São Paulo School of Medicine, São Paulo, SP, Brazil
- Federal University of Fronteira Sul, Realeza, PR, Brazil
| | - Andrew D. Beale
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | | | - Daniel Vartanian
- School of Arts, Science, and Humanities, University of São Paulo, São Paulo, Brazil
| | - Tâmara P. Taporoski
- Department of Psychiatry, University of São Paulo School of Medicine, São Paulo, SP, Brazil
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | - José E. Krieger
- Incor, University of São Paulo School of Medicine, São Paulo, SP, Brazil
| | - Homero Vallada
- Department of Psychiatry, University of São Paulo School of Medicine, São Paulo, SP, Brazil
| | - Josephine Arendt
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | | | | | - Mario Pedrazzoli
- School of Arts, Science, and Humanities, University of São Paulo, São Paulo, Brazil
| | - Malcolm von Schantz
- Department of Psychiatry, University of São Paulo School of Medicine, São Paulo, SP, Brazil
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
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Garaulet M, Qian J, Florez JC, Arendt J, Saxena R, Scheer FAJL. Melatonin Effects on Glucose Metabolism: Time To Unlock the Controversy. Trends Endocrinol Metab 2020; 31:192-204. [PMID: 31901302 PMCID: PMC7349733 DOI: 10.1016/j.tem.2019.11.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/19/2019] [Accepted: 11/21/2019] [Indexed: 12/18/2022]
Abstract
The past decade has witnessed a revival of interest in the hormone melatonin, partly attributable to the discovery that genetic variation in MTNR1B - the melatonin receptor gene - is a risk factor for impaired fasting glucose and type 2 diabetes (T2D). Despite intensive investigation, there is considerable confusion and seemingly conflicting data on the metabolic effects of melatonin and MTNR1B variation, and disagreement on whether melatonin is metabolically beneficial or deleterious, a crucial issue for melatonin agonist/antagonist drug development and dosing time. We provide a conceptual framework - anchored in the dimension of 'time' - to reconcile paradoxical findings in the literature. We propose that the relative timing between elevated melatonin concentrations and glycemic challenge should be considered to better understand the mechanisms and therapeutic opportunities of melatonin signaling in glycemic health and disease.
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Affiliation(s)
- Marta Garaulet
- Department of Physiology, University of Murcia and Research Biomedical Institute of Murcia, Murcia, Spain; Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | - Jingyi Qian
- Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Jose C Florez
- Department of Medicine, Harvard Medical School, Boston, MA, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA; Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA, USA
| | | | - Richa Saxena
- Department of Medicine, Harvard Medical School, Boston, MA, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA; Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA, USA.
| | - Frank A J L Scheer
- Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA; Broad Institute of Massachusetts Institute of Technology (MIT) and Harvard, Cambridge, MA, USA.
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Ruiz F, Beijamini F, Gonçalves B, Middleton B, Krieger J, Vallada H, Arendt J, Pereira A, Knutson K, Pedrazzoli M, von Schantz M. Circadian phase, chronotype and sleep-wake cycle under real-life conditions: the baependi heart study cohort. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
For many years now a treatment mitigating the debilitating effects of jet lag has been sought. Rapid travel across time zones leads, in most people, to temporary symptoms, in particular poor sleep, daytime alertness and poor performance. Mis-timed circadian rhythms are considered to be the main factor underlying jet-lag symptoms, together with the sleep deprivation from long haul flights. Virtually all aspects of physiology are rhythmic, from cells to systems, and circadian rhythms are coordinated by a central pacemaker or clock in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN adapts slowly to changes in time zone, and peripheral clocks or oscillators adapt at different rates, such that the organism is in a state of desynchrony from the external environment and internally. Light exposure is the main factor controlling the circadian system and needs to be considered together with any pharmacological interventions. This review covers the relatively new chronobiotic drugs, which can hasten adaptation of the circadian system, together with drugs directly affecting alertness and sleep propensity. No current treatment can instantly shift circadian phase to a new time zone; however, adaptation can be hastened. The melatoninergic drugs are promising but larger trials in real-life situations are needed. For short stopovers it is recommended to preserve sleep and alertness without necessarily modifying the circadian system. New research suggests that modification of clock function via genetic manipulation may one day have clinical applications.
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Affiliation(s)
- Josephine Arendt
- Faculty of Health and Medical Sciences (FHMS), University of Surrey, Guildford, Surrey, GU2 7XH, UK.
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Abstract
Last year melatonin was 60 years old, or at least its discovery was 60 years ago. The molecule itself may well be almost as old as life itself. So it is time to take yet another perspective on our understanding of its functions, effects and clinical uses. This is not a formal review-there is already a multitude of systematic reviews, narrative reviews, meta-analyses and even reviews of reviews. In view of the extraordinary variety of effects attributed to melatonin in the last 25 years, it is more of an attempt to sort out some areas where a consensus opinion exists, and where placebo controlled, randomized, clinical trials have confirmed early observations on therapeutic uses. The current upsurge of concern about the multiple health problems associated with disturbed circadian rhythms has generated interest in related therapeutic interventions, of which melatonin is one. The present text will consider the physiological role of endogenous melatonin, and the mostly pharmacological effects of exogenous treatment, on the assumption that normal circulating concentrations represent endogenous pineal production. It will concentrate mainly on the most researched, and accepted area of therapeutic use and potential use of melatonin-its undoubted ability to realign circadian rhythms and sleep-since this is the author's bias. It will touch briefly upon some other systems with prominent rhythmic attributes including certain cancers, the cardiovascular system, the entero-insular axis and metabolism together with the use of melatonin to assess circadian status. Many of the ills of the developed world relate to deranged rhythms-and everything is rhythmic unless proved otherwise.
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Abstract
Living for extended periods in Antarctica exposes base personnel to extremes of daylength (photoperiod) and temperature. At the British Antarctic Survey base of Halley, 75°S, the sun does not rise for 110 d in the winter and does not set for 100 d in summer. Photoperiod is the major time cue governing the timing of seasonal events such as reproduction in many species. The neuroendocrine signal providing photoperiodic information to body physiology is the duration of melatonin secretion which reflects the length of the night: longer in the short days of winter and shorter in summer. Light of sufficient intensity and spectral composition serves to suppress production of melatonin and to set the circadian timing and the duration of the rhythm. In humans early observations suggested that bright (>2000 lux) white light was needed to suppress melatonin completely. Shortly thereafter winter depression (Seasonal Affective Disorder or SAD) was described, and its successful treatment by an artificial summer photoperiod of bright white light, sufficient to shorten melatonin production. At Halley dim artificial light intensity during winter was measured, until 2003, at a maximum of approximately 500 lux in winter. Thus a strong seasonal and circadian time cue was absent. It seemed likely that winter depression would be common in the extended period of winter darkness and could be treated with an artificial summer photoperiod. These observations, and predictions, inspired a long series of studies regarding human seasonal and circadian status, and the effects of light treatment, in a small overwintering, isolated community, living in the same conditions for many months at Halley. We found little evidence of SAD, or change in duration of melatonin production with season. However the timing of the melatonin rhythm itself, and/or that of its metabolite 6-sulphatoxymelatonin (aMT6s), was used as a primary marker of seasonal, circadian and treatment changes. A substantial phase delay of melatonin in winter was advanced to summer phase by a two pulse 'skeleton' bright white light treatment. Subsequently a single morning pulse of bright white light was effective with regard to circadian phase and improved daytime performance. The circadian delay evidenced by melatonin was accompanied by delayed sleep (logs and actigraphy): poor sleep is a common complaint in Polar regions. Appropriate extra artificial light, both standard white, and blue enriched, present throughout the day, effectively countered delay in sleep timing and the aMT6s rhythm. The most important factor appeared to be the maximum light experienced. Another manifestation of the winter was a decline in self-rated libido (men only on base at this time). Women on the base showed lower aspects of physical and mental health compared to men. Free-running rhythms were seen in some subjects following night shift, but were rarely found at other times, probably because this base has strongly scheduled activity and leisure time. Complete circadian adaptation during a week of night shift, also seen in a similar situation on North Sea oil rigs, led to problems readapting back to day shift in winter, compared to summer. Here again timed light treatment was used to address the problem. Sleep, alertness and waking performance are critically dependent on optimum circadian phase. Circadian desynchrony is associated with increased risk of major disease in shift workers. These studies provide some groundwork for countering/avoiding circadian desynchrony in rather extreme conditions.
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Affiliation(s)
- Josephine Arendt
- Biochemistry and Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK.
| | - Benita Middleton
- Biochemistry and Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK.
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Korf HW, Klein DC, Arendt J, Pévet P. Andreas Oksche. J Biol Rhythms 2017; 32:99-100. [PMID: 28470124 DOI: 10.1177/0748730417703558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Abstract
Circadian (∼24-hour) timing systems pervade all kingdoms of life and temporally optimize behavior and physiology in humans. Relatively recent changes to our environments, such as the introduction of artificial lighting, can disorganize the circadian system, from the level of the molecular clocks that regulate the timing of cellular activities to the level of synchronization between our daily cycles of behavior and the solar day. Sleep/wake cycles are intertwined with the circadian system, and global trends indicate that these, too, are increasingly subject to disruption. A large proportion of the world's population is at increased risk of environmentally driven circadian rhythm and sleep disruption, and a minority of individuals are also genetically predisposed to circadian misalignment and sleep disorders. The consequences of disruption to the circadian system and sleep are profound and include myriad metabolic ramifications, some of which may be compounded by adverse effects on dietary choices. If not addressed, the deleterious effects of such disruption will continue to cause widespread health problems; therefore, implementation of the numerous behavioral and pharmaceutical interventions that can help restore circadian system alignment and enhance sleep will be important.
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Affiliation(s)
- Gregory D M Potter
- Division of Epidemiology and Biostatistics (G.D.M.P., L.J.H.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom; Chronobiology Section (D.J.S., J.A.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom; Nutritional Epidemiology Group (J.E.C.), School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom; and Division of Cardiovascular & Diabetes Research (P.J.G.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Debra J Skene
- Division of Epidemiology and Biostatistics (G.D.M.P., L.J.H.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom; Chronobiology Section (D.J.S., J.A.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom; Nutritional Epidemiology Group (J.E.C.), School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom; and Division of Cardiovascular & Diabetes Research (P.J.G.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Josephine Arendt
- Division of Epidemiology and Biostatistics (G.D.M.P., L.J.H.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom; Chronobiology Section (D.J.S., J.A.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom; Nutritional Epidemiology Group (J.E.C.), School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom; and Division of Cardiovascular & Diabetes Research (P.J.G.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Janet E Cade
- Division of Epidemiology and Biostatistics (G.D.M.P., L.J.H.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom; Chronobiology Section (D.J.S., J.A.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom; Nutritional Epidemiology Group (J.E.C.), School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom; and Division of Cardiovascular & Diabetes Research (P.J.G.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Peter J Grant
- Division of Epidemiology and Biostatistics (G.D.M.P., L.J.H.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom; Chronobiology Section (D.J.S., J.A.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom; Nutritional Epidemiology Group (J.E.C.), School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom; and Division of Cardiovascular & Diabetes Research (P.J.G.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Laura J Hardie
- Division of Epidemiology and Biostatistics (G.D.M.P., L.J.H.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom; Chronobiology Section (D.J.S., J.A.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom; Nutritional Epidemiology Group (J.E.C.), School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom; and Division of Cardiovascular & Diabetes Research (P.J.G.), LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
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12
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Paul MA, Love RJ, Hawton A, Brett K, McCreary DR, Arendt J. Light Treatment Improves Sleep Quality and Negative Affectiveness in High Arctic Residents During Winter. Photochem Photobiol 2015; 91:567-73. [DOI: 10.1111/php.12418] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 01/03/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Michel A. Paul
- Defence Research and Development Canada; Toronto ON Canada
| | - Ryan J. Love
- Defence Research and Development Canada; Toronto ON Canada
| | - Andrea Hawton
- Defence Research and Development Canada; Toronto ON Canada
| | - Kaighley Brett
- Canadian Forces Health Services Centre (Atlantic); Halifax NS
- Canadian Forces Station; Alert NU Canada
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13
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Paul MA, Love RJ, Hawton A, Arendt J. Sleep and the endogenous melatonin rhythm of high arctic residents during the summer and winter. Physiol Behav 2015; 141:199-206. [PMID: 25615594 DOI: 10.1016/j.physbeh.2015.01.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 01/15/2015] [Accepted: 01/20/2015] [Indexed: 10/24/2022]
Abstract
The seasonal extremes of photoperiod in high latitudes place particular strain on the human circadian system. Arctic residence has been associated with poor sleep in both summer and winter. The goal of the work reported here was to study the circadian rhythms of individuals living in the high Arctic by measuring sleep variables and the timing of melatonin production. Two research trials were conducted in the built environment of CFS Alert (82° 29' 58″ N). Participants wore motion logging devices (actigraphs), which measure ambient light as well as motion, for 1week to provide data on sleep quantity, quality and light exposure. On the penultimate day of each trial, the participants were maintained together in a gymnasium with lounge chairs and saliva was collected at regular intervals to measure melatonin and assess the dim light melatonin onset (DLMO), offset (MelOFF), 50% rise and fall times of the whole profile and total production. In general, sleep duration was found to be significantly different between the January and June data collections at CFS Alert, with participants in June sleeping 50min on average less each day compared to their January counterparts. In June sleep was mistimed in many subjects relative to circadian phase as evidenced by the melatonin rhythm. Exposure to bright evening light was the most likely causal factor and should be avoided in the Arctic summer. The Arctic summer represents a particularly challenging environment for obtaining sufficient sleep. This has implications for the cognitive performance of staff during work hours.
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Affiliation(s)
- Michel A Paul
- Defence Research and Development Canada, Toronto, ON, M3K2C9, Canada
| | - Ryan J Love
- Defence Research and Development Canada, Toronto, ON, M3K2C9, Canada.
| | - Andrea Hawton
- Defence Research and Development Canada, Toronto, ON, M3K2C9, Canada
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14
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Paul MA, Love RJ, Hawton A, Brett K, McCreary DR, Arendt J. Sleep deficits in the High Arctic summer in relation to light exposure and behaviour: use of melatonin as a countermeasure. Sleep Med 2015; 16:406-13. [PMID: 25747331 DOI: 10.1016/j.sleep.2014.12.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/17/2014] [Accepted: 12/19/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND There are conflicting reports regarding seasonal sleep difficulties in polar regions. Herein we report differences in actigraphic sleep measures between two summer trials (collected at Canadian Forces Station Alert, 82.5°N, in 2012 and 2014) and evaluate exogenous melatonin for preventing/treating circadian phase delay due to nocturnal light exposure. METHODS Subjects wore actigraphs continuously to obtain sleep data. Following seven days of actigraphic recording the subjects filled out questionnaires regarding sleep difficulty and psychosocial parameters and subsequently remained in dim light conditions for 24 hours, during which saliva was collected bihourly to measure melatonin. During Trial 2, individuals who reported difficulty sleeping were prescribed melatonin, and a second saliva collection was conducted to evaluate the effect of melatonin on the circadian system. RESULTS Trial 1 subjects collectively had late dim light melatonin onsets and difficulty sleeping; however, the Trial 2 subjects had normally timed melatonin rhythms, and obtained a good quantity of high-quality sleep. Nocturnal light exposure was significantly different between the trials, with Trial 1 subjects exposed to significantly more light between 2200 and 0200h. Melatonin treatment during Trial 2 led to an improvement in the subjective sleep difficulty between the pre- and post-treatment surveys; however there were no significant differences in the objective measures of sleep. CONCLUSIONS The difference in sleep and melatonin rhythms between research participants in June 2012 and June 2014 is attributed to the higher levels of nocturnal light exposure in 2012. The avoidance of nocturnal light is likely to improve sleep during the Arctic summer.
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Affiliation(s)
- Michel A Paul
- Defence Research and Development Canada, Toronto, ON, Canada M3K2C9
| | - Ryan J Love
- Defence Research and Development Canada, Toronto, ON, Canada M3K2C9.
| | - Andrea Hawton
- Defence Research and Development Canada, Toronto, ON, Canada M3K2C9
| | - Kaighley Brett
- Canadian Forces Health Services Centre (Atlantic), Halifax, NS, Canada B3K 5X5; Canadian Forces Station - Alert, Nunavut, Canada
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15
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Arendt J. Why get big in the cold? Size-fecundity relationships explain the temperature-size rule in a pulmonate snail (Physa
). J Evol Biol 2014; 28:169-78. [DOI: 10.1111/jeb.12554] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 11/09/2014] [Accepted: 11/14/2014] [Indexed: 11/26/2022]
Affiliation(s)
- J. Arendt
- Department of Biology; University of California at Riverside; Riverside CA USA
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16
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Merchant NM, Azzopardi DV, Hawwa AF, McElnay JC, Middleton B, Arendt J, Arichi T, Gressens P, Edwards AD. Pharmacokinetics of melatonin in preterm infants. Br J Clin Pharmacol 2014; 76:725-33. [PMID: 23432339 DOI: 10.1111/bcp.12092] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/07/2013] [Indexed: 11/26/2022] Open
Abstract
AIMS Preterm infants are deprived of the normal intra-uterine exposure to maternal melatonin and may benefit from replacement therapy. We conducted a pharmacokinetic study to guide potential therapeutic trials. METHODS Melatonin was administered to 18 preterm infants in doses ranging from 0.04-0.6 μg kg(-1) over 0.5-6 h. Pharmacokinetic profiles were analyzed individually and by population methods. RESULTS Baseline melatonin was largely undetectable. Infants receiving melatonin at 0.1 μg kg(-1) h(-1) for 2 h showed a median half-life of 15.82 h and median maximum plasma concentration of 203.3 pg ml(-1) . On population pharmacokinetics, clearance was 0.045 l h(-1) , volume of distribution 1.098 l and elimination half-life 16.91 h with gender (P = 0.047) and race (P < 0.0001) as significant covariates. CONCLUSIONS A 2 h infusion of 0.1 μg kg(-1) h(-1) increased blood melatonin from undetectable to approximately peak adult concentrations. Slow clearance makes replacement of a typical maternal circadian rhythm problematic. The pharmacokinetic profile of melatonin in preterm infants differs from that of adults so dosage of melatonin for preterm infants cannot be extrapolated from adult studies. Data from this study can be used to guide therapeutic clinical trials of melatonin in preterm infants.
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Affiliation(s)
- Nazakat M Merchant
- Centre for the Developing Brain, King's College London, London, UK; Centre for the Developing Brain, Imperial College, London, UK; Division of Neonatology, Imperial College Healthcare NHS Trust, London, UK; Division of Neonatology, Guy's and St Thomas' NHS Trust, London, UK
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17
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Arendt J. [A few reflections and definitions on the subject of embryonic research]. Bull Soc Sci Med Grand Duche Luxemb 2013:20-26. [PMID: 23808107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Tissue regeneration by embryonic stem cells (ESC) opens new applications for cellular therapy. ECS are used in endocrinology, rheumatology, cardiology, orthopaedics, dermatology and neurology. They come from supernumerary embryos given by their progenitors to science. The moral embryo status is the conflicting point and a hotly debated question. No ethical committee has given any valuable definition. Some countries have set time limits governing research with embryos, while others consider ECS as more akin to things or living beings such as animals.
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Affiliation(s)
- J Arendt
- Centre Hospitalier de Luxembourg, Service de Procréation Médicalement Assistée
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18
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Corbett RW, Middleton B, Arendt J. An hour of bright white light in the early morning improves performance and advances sleep and circadian phase during the Antarctic winter. Neurosci Lett 2012; 525:146-51. [PMID: 22750209 DOI: 10.1016/j.neulet.2012.06.046] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Revised: 06/11/2012] [Accepted: 06/18/2012] [Indexed: 11/29/2022]
Abstract
Previous work has demonstrated that exposure to an hour of bright light in the morning and the evening during the Polar winter has beneficial effects on circadian phase. This study investigated the effect of a single hour of bright white morning light on circadian phase, sleep, alertness and cognitive performance. Nine individuals (eight male, one female, median age 30 years), wintering at Halley Research Station (75°S), Antarctica from 7th May until 6th August 2007, were exposed to bright white light for a fortnight from 08:30 to 09:30 h, with two fortnight control periods on either side. This sequence was performed twice, before and following Midwinter. Light exposure, sleep and alertness were assessed daily by actigraphy, sleep diaries and subjective visual analogue scales. Circadian phase (assessed by urinary 6-sulphatoxymelatonin rhythm) and cognitive performance were evaluated at the end of each fortnight. During light exposure circadian phase was advanced from 4.97 ± 0.96 decimal hours (dh) (mean ± SD) to 4.08 ± 0.68 dh (p = 0.003). Wake-up time was shifted by a similar margin from 8.45 ± 1.83 dh to 7.59 ± 0.78 dh (p < 0.001). Sleep start time was also advanced (p = 0.047) but by a lesser amount, consequently, actual sleep time was slightly reduced. There was no change in objective or subjective measures of sleep quality or subjective measures of alertness. An improvement in cognitive performance was found with both the Single Letter Cancellation Test (p < 0.001) and the Digit Symbol Substitution Test (p = 0.026) with preserved circadian variation. These beneficial effects of a single short duration light treatment may have implications not only for the Antarctic but other remote environments where access to natural light and delayed circadian phase, is problematic. These results require validation in larger studies at varying locations.
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Affiliation(s)
- R W Corbett
- British Antarctic Survey Medical Unit, Derriford Hospital, Plymouth, UK.
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19
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Abstract
At Arctic and Antarctic latitudes, personnel are deprived of natural sunlight in winter and have continuous daylight in summer: light of sufficient intensity and suitable spectral composition is the main factor that maintains the 24-h period of human circadian rhythms. Thus, the status of the circadian system is of interest. Moreover, the relatively controlled artificial light conditions in winter are conducive to experimentation with different types of light treatment. The hormone melatonin and/or its metabolite 6-sulfatoxymelatonin (aMT6s) provide probably the best index of circadian (and seasonal) timing. A frequent observation has been a delay of the circadian system in winter. A skeleton photoperiod (2 × 1-h, bright white light, morning and evening) can restore summer timing. A single 1-h pulse of light in the morning may be sufficient. A few people desynchronize from the 24-h day (free-run) and show their intrinsic circadian period, usually >24 h. With regard to general health in polar regions, intermittent reports describe abnormalities in various physiological processes from the point of view of daily and seasonal rhythms, but positive health outcomes are also published. True winter depression (SAD) appears to be rare, although subsyndromal SAD is reported. Probably of most concern are the numerous reports of sleep problems. These have prompted investigations of the underlying mechanisms and treatment interventions. A delay of the circadian system with "normal" working hours implies sleep is attempted at a suboptimal phase. Decrements in sleep efficiency, latency, duration, and quality are also seen in winter. Increasing the intensity of ambient light exposure throughout the day advanced circadian phase and was associated with benefits for sleep: blue-enriched light was slightly more effective than standard white light. Effects on performance remain to be fully investigated. At 75°S, base personnel adapt the circadian system to night work within a week, in contrast to temperate zones where complete adaptation rarely occurs. A similar situation occurs on high-latitude North Sea oil installations, especially when working 18:00-06:00 h. Lack of conflicting light exposure (and "social obligations") is the probable explanation. Many have problems returning to day work, showing circadian desynchrony. Timed light treatment again has helped to restore normal phase/sleep in a small number of people. Postprandial response to meals is compromised during periods of desynchrony with evidence of insulin resistance and elevated triglycerides, risk factors for heart disease. Only small numbers of subjects have been studied intensively in polar regions; however, these observations suggest that suboptimal light conditions are deleterious to health. They apply equally to people living in temperate zones with insufficient light exposure.
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Affiliation(s)
- Josephine Arendt
- Centre for Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
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20
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Arendt J. [Can one authorize oocyte donation in the Grand Duchy of Luxembourg?]. Bull Soc Sci Med Grand Duche Luxemb 2012:21-31. [PMID: 22822560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In the case of early ovary extinction, the only way to have a child is either adoption or egg/embryo reception by donation. To day, egg donation is prohibited in Luxembourg by ministerial decision in 2003. Germ cell donation is part of artificial reproductive therapy. Oocyte donation, in particular, needs to be done by IVF treatment, which makes it more complicated then sperm donation What makes it more difficult is the fact that there are no oocyte bank yet. Today, prohibition encourages procreative tourism what only wealthy people can afford. Although donation programs are well established many questions arise about egg donation such as refunds, divulging information, women's age limit, health insurance participation.
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Affiliation(s)
- J Arendt
- Service de Médecine de Reproduction, Centre Hospitalier Luxembourg, 4, rue Barblé, L-1210, Luxembourg
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21
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Abstract
The internal circadian clock adapts slowly, if at all, to rapid transitions between different shift schedules. This leads to misalignment (desynchrony) of rhythmic physiological systems, such as sleep, alertness, performance, metabolism and the hormones melatonin and cortisol, with the imposed work-rest schedule. Consequences include sleep deprivation and poor performance. Clock gene variants may influence tolerance of sleep deprivation. Shift work is associated with an increased risk of major disease (heart disease and cancer) and this may also, at least in part, be attributed to frequent circadian desynchrony. Abnormal metabolism has been invoked as a contributory factor to the increased risk of heart disease. There is recent evidence for an increased risk of certain cancers, with hypothesized causal roles of light at night, melatonin suppression and circadian desynchrony. Various strategies exist for coping with circadian desynchrony and for hastening circadian realignment (if desired). The most important factor in manipulating the circadian system is exposure to and/or avoidance of bright light at specific times of the 'biological night'.
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Affiliation(s)
- Josephine Arendt
- Centre for Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
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22
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Warman GR, Pawley MDM, Bolton C, Cheeseman JF, Fernando AT, Arendt J, Wirz-Justice A. Circadian-related sleep disorders and sleep medication use in the New Zealand blind population: an observational prevalence survey. PLoS One 2011; 6:e22073. [PMID: 21789214 PMCID: PMC3138759 DOI: 10.1371/journal.pone.0022073] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 06/14/2011] [Indexed: 11/18/2022] Open
Abstract
STUDY OBJECTIVES To determine the prevalence of self-reported circadian-related sleep disorders, sleep medication and melatonin use in the New Zealand blind population. DESIGN A telephone survey incorporating 62 questions on sleep habits and medication together with validated questionnaires on sleep quality, chronotype and seasonality. PARTICIPANTS PARTICIPANTS WERE GROUPED INTO: (i) 157 with reduced conscious perception of light (RLP); (ii) 156 visually impaired with no reduction in light perception (LP) matched for age, sex and socioeconomic status, and (iii) 156 matched fully-sighted controls (FS). SLEEP HABITS AND DISTURBANCES: The incidence of sleep disorders, daytime somnolence, insomnia and sleep timing problems was significantly higher in RLP and LP compared to the FS controls (p<0.001). The RLP group had the highest incidence (55%) of sleep timing problems, and 26% showed drifting sleep patterns (vs. 4% FS). Odds ratios for unconventional sleep timing were 2.41 (RLP) and 1.63 (LP) compared to FS controls. For drifting sleep patterns, they were 7.3 (RLP) and 6.0 (LP). MEDICATION USE: Zopiclone was the most frequently prescribed sleep medication. Melatonin was used by only 4% in the RLP group and 2% in the LP group. CONCLUSIONS Extrapolations from the current study suggest that 3,000 blind and visually impaired New Zealanders may suffer from circadian-related sleep problems, and that of these, fewer than 15% have been prescribed melatonin. This may represent a therapeutic gap in the treatment of circadian-related sleep disorders in New Zealand, findings that may generalize to other countries.
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Affiliation(s)
- Guy R Warman
- Department of Anaesthesiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
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23
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Paul MA, Gray GW, Lieberman HR, Love RJ, Miller JC, Trouborst M, Arendt J. Phase advance with separate and combined melatonin and light treatment. Psychopharmacology (Berl) 2011; 214:515-23. [PMID: 21069516 DOI: 10.1007/s00213-010-2059-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 10/13/2010] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Melatonin and light treatment are recommended for hastening adaptation to time zone change. We evaluated an afternoon regimen of 3 mg sustained release (SR) melatonin with and without next morning green light treatment for circadian phase advance. Effects of melatonin and light were tested separately and then combined to determine if the total phase change is additive or synergistic. MATERIAL AND METHODS For each condition (melatonin, placebo, light, melatonin plus light), 11 subjects spent from Tuesday evening until Friday afternoon in the laboratory. For all four conditions, the following sleep schedule was maintained: night 1, 2345 to 0630 hours, night 2, 1600 to 0530 hours, and night 3, 2345 to 0700 hours. For the light-only condition, light treatment was administered between 0700 and 0800 hours on Thursday. For melatonin-only or placebo conditions, capsules were administered at 1600 hours on Wednesday. For the combined condition, melatonin was administered at 1600 hours on Wednesday with light treatment between 0600 and 0700 hours on Thursday. Circadian phase was assessed by calculating dim light melatonin onset (DLMO) from salivary melatonin, using a mean baseline +2 standard deviations (BL+2 SD) threshold. For all four conditions, pre-treatment and post-treatment DLMO assessments were on Tuesday and Thursday evenings, respectively. RESULTS Phase advances were: melatonin at 1600 hours, 0.72 h p<0.005, light treatment from 0700 to 0800 hours, 0.31 h, non-significant, and the combined treatment, 1.04 h p<0.0002. CONCLUSION The phase advance from the combination of afternoon melatonin with next morning light is additive.
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Affiliation(s)
- Michel A Paul
- Defence Research & Development Canada, 1133 Sheppard Ave. West, P.O. Box 2000, Toronto, ON, Canada.
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24
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Mottram V, Middleton B, Williams P, Arendt J. The impact of bright artificial white and 'blue-enriched' light on sleep and circadian phase during the polar winter. J Sleep Res 2010; 20:154-61. [PMID: 20723022 DOI: 10.1111/j.1365-2869.2010.00875.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Delayed sleep phase (and sometimes free-run) is common in the Antarctic winter (no natural sunlight) and optimizing the artificial light conditions is desirable. This project evaluated sleep when using 17,000 K blue-enriched lamps compared with standard white lamps (5000 K) for personal and communal illumination. Base personnel, 10 males, five females, 32.5±8 years took part in the study. From 24 March to 21 September 2006 light exposure alternated between 4-5-week periods of standard white (5000 K) and blue-enriched lamps (17,000 K), with a 3-week control before and after extra light. Sleep and light exposure were assessed by actigraphy and sleep diaries. General health (RAND 36-item questionnaire) and circadian phase (urinary 6-sulphatoxymelatonin rhythm) were evaluated at the end of each light condition. Direct comparison (rmanova) of blue-enriched light with white light showed that sleep onset was earlier by 19 min (P=0.022), and sleep latency tended to be shorter by 4 min (P=0.065) with blue-enriched light. Analysing all light conditions, control, blue and white, again provided evidence for greater efficiency of blue-enriched light compared with white (P<0.05), but with the best sleep timing, duration, efficiency and quality in control natural light conditions. Circadian phase was earlier on average in midwinter blue compared with midwinter white light by 45 min (P<0.05). Light condition had no influence on general health. We conclude that the use of blue-enriched light had some beneficial effects, notably earlier sleep, compared with standard white light during the polar winter.
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Affiliation(s)
- Victoria Mottram
- British Antarctic Survey Medical Unit, Derriford Hospital, Plymouth, UK
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25
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Arendt J, Schilling C, Peiffer M, Ginter S, Nahan AF, Lemos C, Dubois M, Thonon F, Jouan C, Gaspard O, Larcher ME, Gomez V, Pereira S, Geimer M. [Retrospective study--pregnancy after assisted medical reproduction from 2001 to 2009 at the Central Hospital of Luxembourg (first section)]. Bull Soc Sci Med Grand Duche Luxemb 2010:247-255. [PMID: 20882743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Retrospective study on a nine year ART practice focusing on pregnancy outcomes and multiple pregnancies, their complications, the gestational duration, delivery options, the new born weights and health statements til the age of two. Post ART pregnancies seem to have an increased complication rate; multiple births are more frequent than with spontaneous conception. The first chapter deals with the entire group. The second chapter analyses several sub-groups according to the ART method employed. The results are compared to publications in PubMed and Medline.
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Affiliation(s)
- J Arendt
- Service de stérilité et de Médecine de Reproduction du Centre Hospitalier de Luxembourg
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26
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Arendt J, Schilling C, Peiffer M, Ginter S, Nahanb AF, Lemosb C, Duboisb M, Thononb F, Jouanb C, Gaspardb O, Larcher ME, Gomez V, Pereira S, Geimer M. [Retrospective studies of pregnancies after assisted medical reproduction from 2001-2009 and Central Hospital in Luxembourg (part 2)]. Bull Soc Sci Med Grand Duche Luxemb 2010:257-270. [PMID: 20882744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The first chapter analyses the ART methods of the Centre Hospitalier of Luxembourg, in the department of reproductive medicine between 2001 and 2009. The second chapter examines the techniques individually, their influence on pregnancy outcomes, the complications on offsprings and their health. The results coincide with literature in that risks are acceptable as long as good medical and biological conditions are maintained. Multiple pregnancies remain the most frequent complication, particularly once out of IVF. These are analysed separately as well as the pregnancies after egg and semen donation.
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Affiliation(s)
- J Arendt
- Service de stérilité et de Médecine de Reproduction du Centre Hospitalier de Luxembourg
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Abstract
Jet lag degrades performance and operational readiness of recently deployed military personnel and other travelers. The objective of the studies reported here was to determine, using a narrow bandwidth light tower (500 nm), the optimum timing of light treatment to hasten adaptive circadian phase advance and delay. Three counterbalanced treatment order, repeated measures studies were conducted to compare melatonin suppression and phase shift across multiple light treatment timings. In Experiment 1, 14 normal healthy volunteers (8 men/6 women) aged 34.9+/-8.2 yrs (mean+/-SD) underwent light treatment at the following times: A) 06:00 to 07:00 h, B) 05:30 to 07:30 h, and C) 09:00 to 10:00 h (active control). In Experiment 2, 13 normal healthy subjects (7 men/6 women) aged 35.6+/-6.9 yrs, underwent light treatment at each of the following times: A) 06:00 to 07:00 h, B) 07:00 to 08:00 h, C) 08:00 to 09:00 h, and a no-light control session (D) from 07:00 to 08:00 h. In Experiment 3, 10 normal healthy subjects (6 men/4 women) aged 37.0+/-7.7 yrs underwent light treatment at the following times: A) 02:00 to 03:00 h, B) 02:30 to 03:30 h, and C) 03:00 to 04:00 h, with a no-light control (D) from 02:30 to 03:30 h. Dim light melatonin onset (DLMO) was established by two methods: when salivary melatonin levels exceeded a 1.0 pg/ml threshold, and when salivary melatonin levels exceeded three times the 0.9 pg/ml sensitivity of the radioimmunoasssy. Using the 1.0 pg/ml DLMO, significant phase advances were found in Experiment 1 for conditions A (p < .028) and B (p < 0.004). Experiment 2 showed significant phase advances in conditions A (p < 0.018) and B (p < 0.003) but not C (p < 0.23), relative to condition D. In Experiment 3, only condition B (p < 0.035) provided a significant phase delay relative to condition D. Similar but generally smaller phase shifts were found with the 2.7 pg/ml DLMO method. This threshold was used to analyze phase shifts against circadian time of the start of light treatment for all three experiments. The best fit curve applied to these data (R(2) = 0.94) provided a partial phase-response curve with maximum advance at approximately 9-11 h and maximum delay at approximately 5-6 h following DLMO. These data suggest largest phase advances will result when light treatment is started between 06:00 and 08:00 h, and greatest phase delays will result from light treatment started between 02:00 to 03:00 h in entrained subjects with a regular sleep wake cycle (23:00 to 07:00 h).
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Affiliation(s)
- Michel A Paul
- Defence Research and Development Canada, Toronto, Canada.
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Abstract
Time-dependent variations in the hormonal and metabolic responses to food are of importance to human health, as postprandial metabolic responses have been implicated as risk factors in a number of major diseases, including cardiovascular disease. Early work reported decreasing glucose tolerance in the evening and at night with evidence for insulin resistance at night. Subsequently an endogenous circadian component, assessed in constant routine (CR), as well as an influence of sleep time, was described for glucose and insulin. Plasma triacylglycerol (TAG), the major lipid component of dietary fat circulating after a meal, also appears to be influenced by both the circadian clock and sleep time with higher levels during biological night (defined as the time between the onset and offset of melatonin secretion) despite identical hourly nutrient intake. These time-dependent differences in postprandial responses have implications for shiftworkers. In the case of an unadapted night shift worker, meals during work time will be taken during biological night. In simulated night shift conditions the TAG response to a standard meal, preceded by either a low-fat or a high-fat premeal, was higher after a nighttime meal than during a daytime meal, and the day/night difference was larger in men than in women. In real night shift workers in Antarctica, insulin, glucose, and TAG all showed an increased response after a nighttime meal (second day of night shift) compared to a daytime meal. Night shift workers are reported to have an approximately 1.5 times higher incidence of heart disease risk and also demonstrate higher TAG levels compared with matched dayworkers. As both insulin resistance and elevated circulating TAG are independent risk factors for heart disease, it is possible that meals at night may contribute to this risk.
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Affiliation(s)
- Linda Morgan
- School of Biomedical and Life Sciences, University of Surrey, Guildford, UK
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Arendt J, Middleton B. Melatonin and the body clock 1. BIOL RHYTHM RES 2009. [DOI: 10.1080/09291010802067114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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30
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Abstract
Jet lag is due to the misalignment of the internal circadian clock(s) with external time cues. For short stopovers (1-2 days) adapting the circadian system is not advised, and at present immediate circadian adaptation is virtually impossible. The use of short-term measures such as judicious naps, caffeine and short acting hypnotics to maintain alertness and sleep is preferred. For intermediate length stays (3-5 days) a phase position with the circadian nadir situated within the sleep period is desirable but difficult to achieve. For longer stays (more than 4-5 days) strategies to hasten adaptation include timed exposure to and avoidance of light. The use of artificial light enriched with short wavelengths may be beneficial. The American Academy of Sleep Medicine recommends the timed use of the chronobiotic melatonin to hasten adaptation. Large individual differences in rate and direction of adaptation make timing treatment according to individual circadian phase difficult. Individual differences in tolerance to the sleep deprivation of jet lag may relate to a length polymorphism in the human clock gene PER3. The maximum efficacy for jet lag avoidance is by pre-flight adaptation, however, this requires time and commitment.
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Affiliation(s)
- Josephine Arendt
- Centre for Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
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31
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Thorne H, Hampton S, Morgan L, Skene DJ, Arendt J. Differences in sleep, light, and circadian phase in offshore 18:00-06:00 h and 19:00-07:00 h shift workers. Chronobiol Int 2008; 25:225-35. [PMID: 18484362 DOI: 10.1080/07420520802106850] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Complaints concerning sleep are high among those who work night shifts; this is in part due to the disturbed relationship between circadian phase and the timing of the sleep-wake cycle. Shift schedule, light exposure, and age are all known to affect adaptation to the night shift. This study investigated circadian phase, sleep, and light exposure in subjects working 18:00-06:00 h and 19:00-07:00 h schedules during summer (May-August). Ten men, aged 46+/-10 yrs (mean+/-SD), worked the 19:00-07:00 h shift schedule for two or three weeks offshore (58 degrees N). Seven men, mean age 41+/-12 yrs, worked the 18:00-06:00 h shift schedule for two weeks offshore (61 degrees N). Circadian phase was assessed by calculating the peak (acrophase) of the 6-sulphatoxymelatonin rhythm measured by radioimmunoassay of sequential urine samples collected for 72 h at the end of the night shift. Objective sleep and light exposure were assessed by actigraphy and subjective sleep diaries. Subjects working 18:00-06:00 h had a 6-sulphatoxymelatonin acrophase of 11.7+/-0.77 h (mean+/-SEM, decimal hours), whereas it was significantly later, 14.6+/-0.55 h (p=0.01), for adapted subjects working 19:00-07:00 h. Two subjects did not adapt to the 19:00-07:00 h night shift (6-sulphatoxymelatonin acrophases being 4.3+/-0.22 and 5.3+/-0.29 h). Actigraphy analysis of sleep duration showed significant differences (p=0.03), with a mean sleep duration for those working 19:00-07:00 h of 5.71+/-0.31 h compared to those working 18:00-06:00 h whose mean sleep duration was 6.64+/-0.33 h. There was a trend to higher morning light exposure (p=0.07) in the 19:00-07:00 h group. Circadian phase was later (delayed on average by 3 h) and objective sleep was shorter with the 19:00-07:00 h than the 18:00-06:00 h shift schedule. In these offshore conditions in summer, the earlier shift start and end time appears to favor daytime sleep.
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Affiliation(s)
- Helen Thorne
- Faculty of Health and Medical Sciences, Neuroendocrinology Group, Centre for Chronobiology, University of Surrey, Guildford, Surrey, UK
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32
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Abstract
The pineal hormone melatonin is able to shift the timing of circadian rhythms, including the sleep-wake cycle, and to promote sleep. Melatonin agonists with similar properties have therapeutic potential for the treatment of circadian rhythm sleep disorders. Depression is specifically targeted by agomelatine, which is also a serotonin-2C (5-HT(2C)) antagonist.
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33
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Abstract
The hormone melatonin is increasingly used for the treatment of certain sleep disorders, particularly those related to disturbed biological rhythms. This article summarises current knowledge of its mechanism of action and identifies situations where there is good evidence for its efficacy. The authors provide advice, based on their own experience and consistent published data, concerning the dose range of melatonin to be used and the critically important question of the timing of treatment. Anecdotal evidence for the use of melatonin needs to be replaced by data from well-controlled, preferably multi-centre, randomised clinical trials.
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Affiliation(s)
- Josephine Arendt
- Centre for Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford.
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Francis G, Bishop L, Luke C, Middleton B, Williams P, Arendt J. Sleep during the Antarctic winter: preliminary observations on changing the spectral composition of artificial light. J Sleep Res 2008; 17:354-60. [PMID: 18564297 DOI: 10.1111/j.1365-2869.2008.00664.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Antarctic Base personnel live for 3 months in winter with no natural sunlight. This project compared sleep, by actigraphy, during periods of increased exposure to white light or blue enriched light in 2003. The primary aim was to help define the optimum spectral composition and intensity of artificial environmental light. Nine men and one woman (33 +/- 7 years, mean +/- SD), wore activity and light monitors continuously from 28.2 to 9.10, and kept sleep diaries. Extra light was provided by light boxes (standard white, 5300 K, or prototype blue enriched, 10,000 K, Philips Lighting), which were turned on in bedrooms and in communal/work areas approximately 08.00-18.00 hours. After a no-treatment control period, 28.2-20.3, sequential 4-5 week periods of first white, then blue light, were imposed with a further control period 19.9-9.10. A limited baseline study in 2002 (no interventions) similarly measured light and activity in seven men and one woman (30 +/- 7 years). Daily light exposure in winter (lux, mean +/- SD) was doubled in 2003 (maximum 1039 +/- 281, average 64 +/- 21), compared to 2002 (572 +/- 276 and 30 +/- 11), P < 0.05 and P < 0.01, with no differences between white and blue light. There were no major differences in sleep between light conditions in 2003. A delay in sleep timing was found in midwinter compared to control (2003, bedtime, P < 0.05, sleep start, P < 0.05, sleep end, P < 0.01) and sleep fragmentation increased (P < 0.05). Sleep efficiency was slightly higher during all blue light periods compared to all white periods (P < 0.05). The use of higher intensity light of suitable spectral composition is proposed.
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Affiliation(s)
- Gavin Francis
- British Antarctic Survey Medical Unit, Derriford Hospital, Plymouth, UK
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Arendt J, Bojkowski C, Folkard S, Franey C, Marks V, Minors D, Waterhouse J, Wever RA, Wildgruber C, Wright J. Some effects of melatonin and the control of its secretion in humans. Ciba Found Symp 2008; 117:266-83. [PMID: 3836818 DOI: 10.1002/9780470720981.ch16] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Whether or not the pineal gland has a significant physiological role in humans is not known. There has nevertheless been speculation about the potential therapeutic use of melatonin (in view of its hypnotic and possible zeitgeber properties) in conditions such as insomnia and jet lag, and in shift-workers. Our work concerns the effects of melatonin administration in humans and the interactions between melatonin and other circadian variables. Chronic (one month), timed (1700 h), low-dose (2 mg daily) melatonin administration to normal subjects without environmental control consistently increased evening fatigue and slightly modified the 24 h prolactin rhythm without effect on cortisol, growth hormone, luteinizing hormone, thyroxine, testosterone or self-rated mood. In five out of 11 subjects the endogenous melatonin rhythm was advanced by one to three hours. During fractional desynchronization of circadian rhythms by increasing imposed 'day' length (26-29 h, 24 days, 500 lux), 5 mg melatonin per os at lights-out in two subjects resulted in better entrainment of the fatigue rhythm to the zeitgeber than in five out of six control subjects, without major consistent effects on other measured circadian variables. Using a new radioimmunoassay for 6-hydroxymelatonin sulphate (aMT6s), the major melatonin metabolite, we have shown that the urinary aMT6s rhythm is closely correlated to that of melatonin in plasma and is completely suppressed by an acute dose of atenolol (100 mg per os), a peripheral beta-adrenergic antagonist. During fractional desynchronization by increasing imposed 'day' length in one subject and decreasing imposed 'day' length in two subjects, the urinary aMT6s rhythm behaved similarly to that of core temperature. The results suggest that fatigue (or alertness) may be entrained by melatonin, but whether critical performance rhythms can be suitably manipulated remains to be clarified. It is likely that melatonin production is linked to the so-called 'strong' circadian oscillator.
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36
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Abstract
Many aspects of human physiology and behavior are dominated by 24-hour circadian rhythms that have a major impact on our health and well-being, including the sleep-wake cycle, alertness and performance patterns, and many daily hormone profiles. These rhythms are spontaneously generated by an internal "pacemaker" in the hypothalamus, and daily light exposure to the eyes is required to keep these circadian rhythms synchronized both internally and with the external environment. Sighted individuals take this daily synchronization process for granted, although they experience some of the consequences of circadian desynchrony when "jetlagged" or working night shifts. Most blind people with no perception of light, however, experience continual circadian desynchrony through a failure of light information to reach the hypothalamic circadian clock, resulting in cyclical episodes of poor sleep and daytime dysfunction. Daily melatonin administration, which provides a replacement synchronizing daily "time cue, " is a promising therapeutic strategy, although optimal treatment dose and timing remain to be determined.
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Affiliation(s)
- Steven W Lockley
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
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37
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Arendt J, Schilling C, Peiffer M. [Biological parameters for evaluation of ovarian reserve and resultant antimullerian hormone]. Bull Soc Sci Med Grand Duche Luxemb 2008:497-502. [PMID: 19024368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
No biological parameter allows a predictive result in ART for ovary stimulation. We studied the interest of dosing AMH in ovary stimulation in balance with the the clinical context.
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Affiliation(s)
- J Arendt
- Service de Médicine de Reproduction du Département de Gynécologie - Obstétrique du Centre Hospitalier de Luxembourg, route d'Arlon, L-1150 Luxembourg.
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38
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Gibbs M, Hampton S, Morgan L, Arendt J. Predicting circadian response to abrupt phase shift: 6-sulphatoxymelatonin rhythms in rotating shift workers offshore. J Biol Rhythms 2007; 22:368-70. [PMID: 17660453 DOI: 10.1177/0748730407302843] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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39
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Checkley SA, Corn TH, Glass IB, Thompson C, Franey C, Arendt J. Neuroendocrine and other studies of the mechanism of antidepressant action of desipramine. Ciba Found Symp 2007; 123:126-47. [PMID: 3028722 DOI: 10.1002/9780470513361.ch8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
It is not known whether in depressed patients antidepressant treatment increases or reduces monoaminergic neurotransmission. Clinical studies are therefore reviewed that investigate adaptive changes at adrenoceptors in depressed patients treated with desipramine, and the net effect of these changes upon neurotransmission. Although in animals chronic desipramine treatment enhances the responsiveness of alpha 1-adrenoceptors to phenylephrine, no such effect could be demonstrated in patients upon the responsiveness of pupil diameter to phenylephrine. However, in keeping with animal studies, clinical evidence of altered responsiveness of alpha 2-adrenoceptors could be demonstrated after chronic desipramine treatment. The alpha 2-mediated growth hormone response to clonidine was increased after one week's treatment with desipramine and then reduced during the second and third weeks of treatment. No clinical measure of the responsiveness of central beta-adrenoceptors is available. However, the secretion of melatonin is a measure of neurotransmission at noradrenergic terminals in the pineal with alpha 1-, alpha 2- and beta 1-adrenoceptors. In normal volunteers the secretion of melatonin was increased by the noradrenaline uptake inhibitors desipramine and (+)-oxaprotiline; (-)-oxaprotiline had no effect. In depressed patients melatonin secretion was increased after three weeks' treatment with desipramine. These and other clinical studies suggest that antidepressant treatments increase noradrenergic neurotransmission in depressed patients.
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42
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Paul MA, Miller JC, Gray G, Buick F, Blazeski S, Arendt J. Circadian phase delay induced by phototherapeutic devices. Aviat Space Environ Med 2007; 78:645-52. [PMID: 17679560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
INTRODUCTION The Canadian Forces has initiated a multiple study project to optimize circadian phase changes using appropriately timed phototherapy and/or ingestion of melatonin for those personnel on long-range deployments and shift workers. The work reported here compared four phototherapeutic devices for efficacy in effecting circadian phase delays. METHODS In a partially counterbalanced treatment order, 14 subjects (7 men and 7 women), ages 18-51 yr, participated in 5 weekly experimental sessions of phototherapy with 4 different phototherapy devices (light tower, light visor, Litebook, LED spectacles) and a no-phototherapy control. Phototherapy was applied from 24:00 to 02:00 on night. (1) Dim light melatonin onset (DLMO) was assessed on night 1 and night. (2) Subjects were tested for psychomotor performance (serial reaction time, logical reasoning, and serial subtraction tasks) and completed the Stanford Sleepiness Scale on night 1 at 19:00, 23:00, 01:00, 02:00, and 03:00. After phototherapy, subjects completed a phototherapy side-effects questionnaire. RESULTS All phototherapy devices produced melatonin suppression and significant phase delays. Sleepiness was significantly decreased with the light tower, the light visor, and the Litebook. Task performance was only slightly improved with phototherapy. The LED spectacles and light visor caused greater subjective performance impairment, more difficulty viewing the computer monitor and reading printed text than the light tower or the Litebook. The light visor, the Litebook, and the LED spectacles caused more eye discomfort than the light tower. CONCLUSIONS The light tower was the best device, producing melatonin suppression and circadian phase change while relatively free of side effects.
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43
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Vandewalle G, Middleton B, Rajaratnam SMW, Stone BM, Thorleifsdottir B, Arendt J, Dijk DJ. Robust circadian rhythm in heart rate and its variability: influence of exogenous melatonin and photoperiod. J Sleep Res 2007; 16:148-55. [PMID: 17542944 DOI: 10.1111/j.1365-2869.2007.00581.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heart rate (HR) and heart rate variability (HRV) undergo marked fluctuations over the 24-h day. Although controversial, this 24-h rhythm is thought to be driven by the sleep-wake/rest-activity cycle as well as by endogenous circadian rhythmicity. We quantified the endogenous circadian rhythm of HR and HRV and investigated whether this rhythm can be shifted by repeated melatonin administration while exposed to an altered photoperiod. Eight healthy males (age 24.4 +/- 4.4 years) participated in a double-blind cross-over design study. In both conditions, volunteers were scheduled to 16 h-8 h rest : wake and dark : light cycles for nine consecutive days preceded and followed by 29-h constant routines (CR) for assessment of endogenous circadian rhythmicity. Melatonin (1.5 mg) or placebo was administered at the beginning of the extended sleep opportunities. For all polysomnographically verified wakefulness periods of the CR, we calculated the high- (HF) and low- (LF) frequency bands of the power spectrum of the R-R interval, the standard deviation of the normal-to-normal (NN) intervals (SDNN) and the square root of the mean-squared difference of successive NN intervals (rMSSD). HR and HRV variables revealed robust endogenous circadian rhythms with fitted maxima, respectively, in the afternoon (16:36 hours) and in the early morning (between 05:00 and 06:59 hours). Melatonin treatment phase-advanced HR, HF, SDNN and rMSSD, and these shifts were significantly greater than after placebo treatment. We conclude that endogenous circadian rhythmicity influences autonomic control of HR and that the timing of these endogenous rhythms can be altered by extended sleep/rest episodes and associated changes in photoperiod as well as by melatonin treatment.
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Abstract
People who are blind, in addition to having to cope with partial or no sight, have an added handicap; the transmission of ocular light from the retina to their circadian clock is impaired. At its worse, for example in people with both eyes enucleated, this lesion results in desynchronisation of the biological clock (located in the hypothalamic suprachiasmatic nuclei) from the 24h day/night environment. While in a desynchronised state, symptoms akin to jet lag are experienced (e.g., daytime sleepiness, poor night sleep, reduced alertness and performance during waking). This is a lifelong condition. Daily administration of exogenous melatonin is the current treatment of choice for this so-called "non-24h sleep/wake disorder". Melatonin has been shown to correct the underlying circadian rhythm abnormality as well as improve sleep and reduce daytime napping. The effectiveness of melatonin therapy depends upon its time of administration relative to the timing of the person's circadian clock. If practicable, assessment of an individual's circadian phase (by measurement of the endogenous melatonin rhythm in plasma, saliva or urine) is recommended prior to commencing treatment to optimise melatonin's effectiveness.
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Affiliation(s)
- Debra J Skene
- Centre for Chronobiology, School of Biomedical and Molecular Sciences, University of Surrey, Guildford GU2 7XH, UK.
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45
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Bielecki TM, Gazdzik TS, Arendt J, Szczepanski T, Król W, Wielkoszynski T. Antibacterial effect of autologous platelet gel enriched with growth factors and other active substances. ACTA ACUST UNITED AC 2007; 89:417-20. [PMID: 17356164 DOI: 10.1302/0301-620x.89b3.18491] [Citation(s) in RCA: 242] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Platelet-rich plasma is a new inductive therapy which is being increasingly used for the treatment of the complications of bone healing, such as infection and nonunion. The activator for platelet-rich plasma is a mixture of thrombin and calcium chloride which produces a platelet-rich gel. We analysed the antibacterial effect of platelet-rich gel in vitro by using the platelet-rich plasma samples of 20 volunteers. In vitro laboratory susceptibility to platelet-rich gel was determined by the Kirby-Bauer disc-diffusion method. Baseline antimicrobial activity was assessed by measuring the zones of inhibition on agar plates coated with selected bacterial strains. Zones of inhibition produced by platelet-rich gel ranged between 6 mm and 24 mm (mean 9.83 mm) in diameter. Platelet-rich gel inhibited the growth of Staphylococcus aureus and was also active against Escherichia coli. There was no activity against Klebsiella pneumoniae, Enterococcus faecalis, and Pseudomonas aeruginosa. Moreover, platelet-rich gel seemed to induce the in vitro growth of Ps. aeruginosa, suggesting that it may cause an exacerbation of infections with this organism. We believe that a combination of the inductive and antimicrobial properties of platelet-rich gel can improve the treatment of infected delayed healing and nonunion.
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Affiliation(s)
- T M Bielecki
- Department and Clinic of Orthopaedics, Medical University of Silesia, Sosnowiec, Poland.
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46
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Arendt J. [Ethical preoccupations in the daily practice of medically assisted reproduction in the Grand Duchy of Luxembourg]. Bull Soc Sci Med Grand Duche Luxemb 2007:7-15. [PMID: 17955588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Ethical questions are daily in usual ART practice. The answers differ from the existence or not of legal resolutions. In Grand Duchy of Luxembourg, there is no law on ART practice, by now. Practice is based human sense, ethical commission guide lines and partly on French bioethical law July, 1994. We discuss several topics encountered in daily practice.
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Affiliation(s)
- J Arendt
- Centre Hospitalier de Luxembourg, Maternité, 120, route d'Arlon, L-1150 Luxembourg
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47
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Lockley SW, Arendt J, Skene DJ. Visual impairment and circadian rhythm disorders. Dialogues Clin Neurosci 2007; 9:301-14. [PMID: 17969867 PMCID: PMC3202494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/25/2024]
Abstract
Many aspects of human physiology and behavior are dominated by 24-hour circadian rhythms that have a major impact on our health and well-being, including the sleep-wake cycle, alertness and performance patterns, and many daily hormone profiles. These rhythms are spontaneously generated by an internal "pacemaker" in the hypothalamus, and daily light exposure to the eyes is required to keep these circadian rhythms synchronized both internally and with the external environment. Sighted individuals take this daily synchronization process for granted, although they experience some of the consequences of circadian desynchrony when "jetlagged" or working night shifts. Most blind people with no perception of light, however, experience continual circadian desynchrony through a failure of light information to reach the hypothalamic circadian clock, resulting in cyclical episodes of poor sleep and daytime dysfunction. Daily melatonin administration, which provides a replacement synchronizing daily "time cue, " is a promising therapeutic strategy, although optimal treatment dose and timing remain to be determined.
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Affiliation(s)
- Steven W Lockley
- Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
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48
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Arendt J. A tribute to Aaron Lerner. Chronobiol Int 2007; 24:383-5. [PMID: 17511116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
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49
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Abstract
Ocular light plays a key role in human physiology by transmitting time of day information. The production of the pineal gland hormone melatonin is under the control of the light-dark cycle. Its profile of secretion defines biological night and it has been called the 'darkness hormone'. Light mediates a number of non-visual responses, such as phase shifting the internal circadian clock, increasing alertness, heart rate and pupil constriction. Both exogenous melatonin and light, if appropriately timed, can phase shift the human circadian system. These 'chronobiotic' effects of light and melatonin have been used successfully to alleviate and correct circadian rhythm disorders, such as those experienced following travel across time zones, in night shift work and in circadian sleep disorders. The effectiveness of melatonin and light are currently being optimized in terms of time of administration, light intensity, duration and wavelength, and melatonin dose and formulation. The aim of this review is not to replicate information that has been reported in a number of reviews of the human circadian timing system and the role of melatonin and light, but rather to extract findings relevant to the field of clinical biochemistry.
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Affiliation(s)
- Debra J Skene
- Centre for Chronobiology, School of Biomedical and Molecular Sciences, University of Surrey, Guildford GU2 7XH, UK.
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50
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Abstract
Melatonin signals time of day and time of year in mammals by virtue of its pattern of secretion, which defines 'biological night.' It is supremely important for research on the physiology and pathology of the human biological clock. Light suppresses melatonin secretion at night using pathways involved in circadian photoreception. The melatonin rhythm (as evidenced by its profile in plasma, saliva, or its major metabolite, 6-sulphatoxymelatonin [aMT6s] in urine) is the best peripheral index of the timing of the human circadian pacemaker. Light suppression and phase-shifting of the melatonin 24 h profile enables the characterization of human circadian photoreception, and circulating concentrations of the hormone are used to investigate the general properties of the human circadian system in health and disease. Suppression of melatonin by light at night has been invoked as a possible influence on major disease risk as there is increasing evidence for its oncostatic effects. Exogenous melatonin acts as a 'chronobiotic.' Acutely, it increases sleep propensity during 'biological day.' These properties have led to successful treatments for serveal circadian rhythm disorders. Endogenous melatonin acts to reinforce the functioning of the human circadian system, probably in many ways. The future holds much promise for melatonin as a research tool and as a therapy for various conditions.
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Affiliation(s)
- Josephine Arendt
- Centre for Chronobiology, School of Biomedical and Molecular Sciences, University of Surrey, Guildford, England.
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