1
|
Yousefzadehfard Y, Wechsler B, DeLorenzo C. Human circadian rhythm studies: Practical guidelines for inclusion/exclusion criteria and protocol. Neurobiol Sleep Circadian Rhythms 2022; 13:100080. [PMID: 35989718 PMCID: PMC9382328 DOI: 10.1016/j.nbscr.2022.100080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/03/2022] Open
Abstract
As interest in circadian rhythms and their effects continues to grow, there is an increasing need to perform circadian studies in humans. Although the constant routine is the gold standard for these studies, there are advantages to performing more naturalistic studies. Here, a review of protocols for such studies is provided along with sample inclusion and exclusion criteria. Sleep routines, drug use, shift work, and menstrual cycle are addressed as screening considerations. Regarding protocol, best practices for measuring melatonin, including light settings, posture, exercise, and dietary habits are described. The inclusion/exclusion recommendations and protocol guidelines are intended to reduce confounding variables in studies that do not involve the constant routine. Given practical limitations, a range of recommendations is provided from stringent to lenient. The scientific rationale behind these recommendations is discussed. However, where the science is equivocal, recommendations are based on empirical decisions made in previous studies. While not all of the recommendations listed may be practical in all research settings and with limited potential participants, the goal is to allow investigators to make well informed decisions about their screening procedures and protocol techniques and to improve rigor and reproducibility, in line with the objectives of the National Institutes of Health.
Collapse
Affiliation(s)
- Yashar Yousefzadehfard
- Center for Understanding Biology Using Imaging Technology, Department of Psychiatry, Stony Brook University, Stony Brook, NY, USA.,Department of Psychiatry, Texas Tech University Health Science Center, Midland, TX, USA
| | - Bennett Wechsler
- Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, USA
| | - Christine DeLorenzo
- Center for Understanding Biology Using Imaging Technology, Department of Psychiatry, Stony Brook University, Stony Brook, NY, USA
| |
Collapse
|
2
|
Touitou Y, Point S. Effects and mechanisms of action of light-emitting diodes on the human retina and internal clock. ENVIRONMENTAL RESEARCH 2020; 190:109942. [PMID: 32758719 DOI: 10.1016/j.envres.2020.109942] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/29/2020] [Accepted: 07/10/2020] [Indexed: 05/11/2023]
Abstract
White light-emitting diodes (LEDs) will likely become the most used lighting devices worldwide in the future because of their very low prices over the course of their long lifespans which can be up to several tens of thousands of hours. The expansion of LED use in both urban and domestic lighting has prompted questions regarding their possible health effects, because the light that they provide is potentially high in the harmful blue band (400-500 nm) of the visible light spectrum. Research on the potential effects of LEDs and their blue band on human health has followed three main directions: 1) examining their retinal phototoxicity; 2) examining disruption of the internal clock, i.e., an out-of-sync clock, in shift workers and night workers, including the accompanying health issues, most concerningly an increased relative risk of cancer; and 3) examining risky, inappropriate late-night use of smartphones and consoles among children and adolescents. Here, we document the recognized or potential health issues associated with LED lighting together with their underlying mechanisms of action. There is so far no evidence that LED lighting is deleterious to human retina under normal use. However, exposure to artificial light at night is a new source of pollution because it affects the circadian clock. Blue-rich light, including cold white LEDs, should be considered a new endocrine disruptor, because it affects estrogen secretion and has unhealthful consequences in women, as demonstrated to occur via a complex mechanism.
Collapse
Affiliation(s)
- Yvan Touitou
- Unité de Chronobiologie, Fondation A. de Rothschild, 75019, Paris, France.
| | | |
Collapse
|
3
|
Cornelissen G, Sothern RB, Sackett-Lundeen L, Uezono K, Otsuka K. Obituary: Pietro Cugini (13 December 1936 – 6 April 2020). Chronobiol Int 2020. [DOI: 10.1080/07420528.2020.1781361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | - Robert B Sothern
- Halberg Chronobiology Center, University of Minnesota, Minneapolis, MN, USA
| | | | - Keiko Uezono
- Institute of Health Science, Kyushu University, Fukuoka, Japan
| | - Kuniaki Otsuka
- Halberg Chronobiology Center, University of Minnesota, Minneapolis, MN, USA
- Executive Medical Center, Totsuka Royal Clinic, Tokyo Women’s Medical University, Tokyo, Japan
| |
Collapse
|
4
|
Saksvik-Lehouillier I, Harrison SL, Marshall LM, Tranah GJ, Ensrud K, Ancoli-Israel S, Clemons A, Redline S, Stone KL, Schernhammer ES. Association of Urinary 6-Sulfatoxymelatonin (aMT6s) Levels and Objective and Subjective Sleep Measures in Older Men: The MrOS Sleep Study. J Gerontol A Biol Sci Med Sci 2015; 70:1569-77. [PMID: 26265731 DOI: 10.1093/gerona/glv088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 05/27/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Sleep and melatonin have been associated with healthy aging. In this study, we examine the association between melatonin levels and sleep among older men. METHODS Cross-sectional study of a community-dwelling cohort of 2,821 men aged 65 years or older recruited from six U.S. centers. First morning void urine samples were collected to measure melatonin's major urinary metabolite, 6-sulfatoxymelatonin (aMT6s). We also assessed objective and subjective sleep parameters. We used logistic regression models to calculate multivariate (MV) odds ratios (ORs), and 95% confidence intervals (CIs) adjusted for important demographic variables and comorbidities. RESULTS In the overall sample, the only significant finding in fully adjusted models was that aMT6s levels were inversely associated with subjectively measured daytime sleepiness (sleepiness mean score of 5.79 in the top aMT6s quartile, and 6.26 in the bottom aMT6s quartile, MV OR, 1.32; 95% CI, 0.95-1.84; p trend ≤ .02). When restricting to men without β-blocker use (a known melatonin suppressant), aMT6s levels were significantly associated with shorter sleep time, that is, less than 5 hours (MV OR, = 1.90; 95% CI, 1.21-2.99; p trend = .01), and worse sleep efficiency, that is, less than 70% (MV OR, 1.58; 95% CI, 1.28-2.65; p trend < .001). aMT6s were not associated with subjective sleep quality or respiratory disturbance in any of our analyses. CONCLUSION Lower nocturnal melatonin levels were associated with worsened daytime sleepiness, sleep efficiency, and shorter sleep time in older men. The role of circadian interventions, and whether melatonin levels are a modifiable risk factor for poor sleep in older men, warrants further study.
Collapse
Affiliation(s)
| | | | - Lynn M Marshall
- Department of Orthopaedics and Rehabilitation, Oregon Health & Science University, Portland. Department of Medicine, Bone and Mineral Unit, Oregon Health & Science University, Portland
| | - Greg J Tranah
- Research Institute, California Pacific Medical Center, San Francisco
| | - Kristine Ensrud
- Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System, Minnesota. Department of Medicine, University of Minnesota, Minneapolis. Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis
| | - Sonia Ancoli-Israel
- Department of Psychiatry and Department of Medicine, University of California, San Diego, La Jolla
| | - Aaron Clemons
- Oregon Clinical and Translational Research Institute (OCTRI) Core Laboratory, Oregon Health & Science University, Portland
| | - Susan Redline
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts
| | - Katie L Stone
- Research Institute, California Pacific Medical Center, San Francisco
| | - Eva S Schernhammer
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts. Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts
| | | |
Collapse
|
5
|
Markus RP, Silva CLM, Franco DG, Barbosa EM, Ferreira ZS. Is modulation of nicotinic acetylcholine receptors by melatonin relevant for therapy with cholinergic drugs? Pharmacol Ther 2010; 126:251-62. [PMID: 20398699 DOI: 10.1016/j.pharmthera.2010.02.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Accepted: 02/24/2010] [Indexed: 12/31/2022]
Abstract
Melatonin, the darkness hormone, synchronizes several physiological functions to light/dark cycle. Besides the awake/sleep cycle that is intuitively linked to day/night, daily variations in memory acquisition and innate or acquired immune responses are some of the major activities linked to melatonin rhythm. The daily variation of these complex processes is due to changes in specific mechanisms. In the last years we focused on the influence of melatonin on the expression and function of nicotinic acetylcholine receptors (nAChRs). Melatonin, either "in vivo" or "in vitro", increases, in a selective manner, the efficiency of alpha-bungarotoxin (alpha-BTX)-sensitive nAChRs. Melatonin's effect on receptors located in rat sympathetic nerve terminals, cerebellum, skeletal muscle and chick retina, was tested. We observed that melatonin is essential for the development of alpha-BTX-sensitive nAChRs, and important for receptor maintenance in aging models. Taking into account that both melatonin and alpha-7 nAChRs (one of the subtypes sensitive to alpha-BTX) are involved in the development of Alzheimer's disease, here we discuss the possibility of a therapeutic strategy focused on both melatonin replacement and its potential association with cholinergic drugs.
Collapse
Affiliation(s)
- Regina P Markus
- Laboratory of Chronopharmacology, Department of Physiology, Institute of Bioscience, Universidade de São Paulo, Brazil.
| | | | | | | | | |
Collapse
|
6
|
|
7
|
Hardeland R, Coto-Montes A, Poeggeler B. Circadian rhythms, oxidative stress, and antioxidative defense mechanisms. Chronobiol Int 2004; 20:921-62. [PMID: 14680136 DOI: 10.1081/cbi-120025245] [Citation(s) in RCA: 231] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Endogenous circadian and exogenously driven daily rhythms of antioxidative enzyme activities and of low molecular weight antioxidants (LMWAs) are described in various phylogenetically distant organisms. Substantial amplitudes are detected in several cases, suggesting the significance of rhythmicity in avoiding excessive oxidative stress. Mammalian and/or avian glutathione peroxidase and, as a consequence, glutathione reductase activities follow the rhythm of melatonin. Another hint for an involvement of melatonin in the control of redox processes is seen in its high-affinity binding to cytosolic quinone reductase 2, previously believed to be a melatonin receptor. Although antioxidative protection by pharmacological doses of melatonin is repeatedly reported, explanations of these findings are still insufficient and their physiological and chronobiological relevance is not yet settled. Recent data indicate a role of melatonin in the avoidance of mitochondrial radical formation, a function which may prevail over direct scavenging. Rhythmic changes in oxidative damage of protein and lipid molecules are also reported. Enhanced oxidative protein modification accompanied by a marked increase in the circadian amplitude of this parameter is detected in the Drosophila mutant rosy, which is deficient in the LMWA urate. Preliminary evidence for the significance of circadian rhythmicity in diminishing oxidative stress comes from clock mutants. In Drosophila, moderately enhanced protein damage is described for the arrhythmic and melatonin null mutant per0, but even more elevated, periodic damage is found in the short-period mutant per(s), synchronized to LD 12:12. Remarkably large increases in oxidative protein damage, along with impairment of tissue integrity and--obviously insufficient--compensatory elevations in protective enzymes are observed in a particularly vulnerable organ, the Harderian gland, of another short-period mutant tau, in the Syrian hamster. Mice deficient in the per2 gene homolog are reported to be cancer-prone, a finding which might also relate to oxidative stress. In the dinoflagellate Lingulodinium polyedrum [Gonyaulax polyedra], various treatments that cause oxidative stress result in strong suppressions of melatonin and its metabolite 5-methoxytryptamine (5-MT) and to secondary effects on overt rhythmicity. The glow maximum, depending on the presence of elevated 5-MT at the end of subjective night, decreases in a dose-dependent manner already under moderate, non-lethal oxidative stress, but is restored by replenishing melatonin. Therefore, a general effect of oxidative stress may consist in declines of easily oxidizable signaling molecules such as melatonin, and this can have consequences on the circadian intraorganismal organization and expression of overt rhythms. Recent findings on a redox-sensitive input into the core oscillator via modulation of NPAS2/BMAL1 or CLK/BMAL1 heterodimer binding to DNA indicate a direct influence of cellular redox balance, including oxidative stress, on the circadian clock.
Collapse
Affiliation(s)
- Rüdiger Hardeland
- Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Germany.
| | | | | |
Collapse
|
8
|
Abstract
The pineal hormone, melatonin, has widespread effects on the body. The aim of this review is to consider the specific interactions between melatonin and human physiological functions associated with sport and exercise medicine. Separate researchers have reported that melatonin concentrations increase, decrease and remain unaffected by bouts of exercise. Such conflicting findings may be explained by inter-study differences in lighting conditions and the time of day the study participants have exercised. Age and fitness status have also been identified as intervening factors in exercise-mediated changes in melatonin concentration. The administration of exogenous melatonin leads to hypnotic and hypothermic responses in humans, which can be linked to immediate reductions in short-term mental and physical performance. Depending on the dose of melatonin, these effects may still be apparent 3-5 hours after administration for some types of cognitive performance, but effects on physical performance seem more short-lived. The hypothesis that the hypothermic effects of melatonin lead to improved endurance performance in hot environments is not supported by evidence from studies involving military recruits who exercised at relatively low intensities. Nevertheless, no research group has examined such a hypothesis with athletes as study participants and with the associated more intense levels of exercise. The fact that melatonin has also been found to preserve muscle and liver glycogen in exercised rats adds weight to the notion that melatonin might affect endurance exercise in humans. Melatonin has been successfully used to alleviate jet lag symptoms of travellers and there is also a smaller amount of evidence that the hormone helps shiftworkers adjust to nocturnal regimens. Nevertheless, the symptoms of jet lag and shiftwork problems have primarily included sleep characteristics rather than performance variables. The few studies that have involved athletes and performance-related symptoms have produced equivocal results. Melatonin has also been found to be useful for treating some sleeping disorders, but interactions between sleep, melatonin and exercise have not been studied extensively with trained study participants. It is unknown whether melatonin plays a role in some exercise training-related problems such as amenorrhoea and over-training syndrome.
Collapse
Affiliation(s)
- Greg Atkinson
- School of Sport and Exercise Sciences, Loughborough University, Loughborough, Leicestershire, UK.
| | | | | | | |
Collapse
|
9
|
Leger D, Laudon M, Zisapel N. Nocturnal 6-sulfatoxymelatonin excretion in insomnia and its relation to the response to melatonin replacement therapy. Am J Med 2004; 116:91-5. [PMID: 14715322 DOI: 10.1016/j.amjmed.2003.07.017] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE Melatonin, which is produced by the pineal gland at night, is an endogenous sleep regulator. Both sleep disorders and impaired melatonin production are common among the elderly. We examined the excretion of the major melatonin metabolite 6-sulfatoxymelatonin in insomnia patients aged >or=55 years and its relation with the subsequent response to melatonin therapy. METHODS We studied 517 insomnia patients, along with 29 age-matched and 30 younger healthy volunteers. Nocturnal urinary 6-sulfatoxymelatonin excretion was assessed between 10 pm and 10 am. Three hundred and ninety-six of the insomnia patients were treated for 2 weeks with placebo and for 3 weeks with 2 mg per night of controlled-release melatonin, of which 372 provided complete datasets. Clinical response, assessed with the Leeds Sleep Evaluation Questionnaire, was defined as an improvement of 10 mm or more on the visual analog scales. RESULTS Mean (+/- SD) 6-sulfatoxymelatonin excretion was lower in the insomnia patients (9.0 +/- 8.3 microg per night) than in volunteers of the same age (18.1 +/- 12.7 microg per night, P <0.05) and in younger volunteers (24.2 +/- 11.9 microg per night, P <0.05). About 30% of patients (112/372) excreted <or=3.5 microg of sulfatoxymelatonin per night, which is considered to be lower than normal for this age group. These "low excretors" had a significantly higher response to melatonin replacement therapy (58% [65/112] vs. 47% [122/260], P <0.05). CONCLUSION Low nocturnal melatonin production is associated with insomnia in patients aged 55 years or older, and identifies patients who are somewhat more likely to respond to melatonin replacement.
Collapse
Affiliation(s)
- Damien Leger
- Centre du Sommeil, Hotel-Dieu de Paris, Paris, France
| | | | | |
Collapse
|
10
|
Selmaoui B, Touitou Y. Reproducibility of the circadian rhythms of serum cortisol and melatonin in healthy subjects: a study of three different 24-h cycles over six weeks. Life Sci 2003; 73:3339-49. [PMID: 14572876 DOI: 10.1016/j.lfs.2003.05.007] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Plasma melatonin and cortisol are characterized by a marked circadian rhythm, but little information is available about the reproducibility and stability of these rhythms over several weeks in the same subjects. This study examined the characteristics of these rhythms in 31 healthy human subjects 20 to 30 years of age. They were synchronized with a diurnal activity from 0800 to 2300 and nocturnal rest. They participated in three 24-hour sessions (S1, S2, and S3): S2 took place two weeks after S1 and S3 4 weeks after S2. Blood samples were taken during each session at 3-hour intervals from 1100 to 2000 and hourly from 2200 to 0800. Comparison of the circadian rhythms between groups used repeated measures 2-way ANOVA, the cosinor method, and Bingham's test. Intraindividual variations were compared by the cosinor method and Bingham's test. The groups did not differ, but a slight difference in the amplitude or acrophase of individual circadian rhythms was observed in 5 of 31 subjects for melatonin and 1 of 31 for cortisol. The circadian means did not differ over the three sessions. These results show that the circadian profile of cortisol and melatonin are highly reproducible over a six-week period, in both individuals and groups. Our study clearly shows that these hormones can be considered to be stable markers of the circadian time structure and therefore useful tools to validate rhythms' synchronisation of human subjects.
Collapse
Affiliation(s)
- Brahim Selmaoui
- Faculté de Médecine Pitié-Salpêtrière, Service de Biochimie Médicale et Biologie Moléculaire, 91 Boulevard de l'Hôpital 75634 Paris Cedex 13, France
| | | |
Collapse
|
11
|
Zhao ZY, Lu FH, Xie Y, Fu YR, Bogdan A, Touitou Y. Cortisol secretion in the elderly. Influence of age, sex and cardiovascular disease in a Chinese population. Steroids 2003; 68:551-5. [PMID: 12906940 DOI: 10.1016/s0039-128x(03)00083-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Adrenal function and aging have been the object of intense interest in recent years. In this study we analyzed morning (08:00 h) serum cortisol concentrations from a sample of Chinese subjects aged from 31 to 110 years. These levels differed according to age, health status and sex, although the sex difference was confirmed only among the healthy elderly. These results suggest that age (older than 60 years), disease and male sex are associated with increased morning serum cortisol levels in a Chinese population.
Collapse
Affiliation(s)
- Zi-Yan Zhao
- Anti-Senility Research Center of Shandong, Shandong Academy of Medical Sciences, 250062, Jinan, PR China.
| | | | | | | | | | | |
Collapse
|
12
|
Abstract
The pineal hormone melatonin is the mediator of external light to physiologic adaptation to day and night rhythms, it regulates reproduction in animals but attempts to utilize melatonin in women for contraception have failed. Melatonin seems to be the natural hormone to facilitate sleep in insomniac patients and causes no hang over. When applied together with benzodiazepine it allows reduction of benzodiazepine without withdrawal effects. It should be applied 2 h before sleeping time in doses between 3 and 5 mg. Melatonin acts via the gamma-aminobutyric acid- and benzodiazepine receptor explaining its success in treatment of seizures in children and in adults. Constant application of benzodiazepine reduced the production of natural melatonin in rats, supporting the evidence that long-term application of benzodiazepine in humans does not restore sleeping habits but reduces natural sleeping habits even more. Low melatonin levels were seen in bulimia or neuralgia and in women with fibromyalgia; replacement reduced pain, sleeping disorders, and depression in fibromyalgia and bulimia. Melatonin profiles are a diagnostic tool to distinguish between several forms of depression, like major depression, winter depression (SAD), unipolar depression, delayed sleep phase syndrome (DSPS). In patients with a major depression success with antidepressants correlated with an increase in their melatonin profiles but only patients suffering from DSPS can be successfully treated with melatonin. In perimenopausal women melatonin administration did produce a change in LH, FSH and thyroid hormones. Some oncostatic properties are supported by cell culture work and studies in animals. In Nordic countries indigenous people suffer less from breast and prostate cancer, winter darkness seems to protect. The supposedly increased melatonin levels created the 'melatonin hypothesis'. Epidemiological studies did show that blind people indeed have half the rate of breast cancers, supporting the hypothesis. Controversial results concerning melatonin and insulin resistance and glucose tolerance have been published. In postmenopausal women application of melatonin reduced glucose tolerance and insulin sensitivity. Pregnant women should avoid melatonin, since its teratogenic effect is not known. Patients suffering from non-hormone dependent tumors, like leukemia, should avoid melanin, since tumor growth was promoted in animal experiments. It can be expected that melatonin will receive wide consideration for treatment of sleeping disturbances, jet lag, and fibromyalgia once an oral formulation becomes available in Europe.
Collapse
Affiliation(s)
- Uwe D Rohr
- Department of Gynecology and Obstetrics, University Hospital, Essen, Germany.
| | | |
Collapse
|