High sensitivity and interindividual variability in the response of the human circadian system to evening light

Proceedings of the National Academy of Sciences, Journal Year: 2019, Volume and Issue: 116(24), P. 12019 - 12024

Published: May 28, 2019

Before the invention of electric lighting, humans were primarily exposed to intense (>300 lux) or dim (<30 environmental light-stimuli at extreme ends circadian system's dose-response curve light. Today, spend hours per day intermediate light intensities (30-300 lux), particularly in evening. Interindividual differences sensitivity evening this intensity range could therefore represent a source vulnerability disruption by modern lighting. We characterized individual-level curves light-induced melatonin suppression using within-subjects protocol. Fifty-five participants (aged 18-30) control (<1 and experimental levels (10-2,000 lux for 5 h) Melatonin was determined each level, effective dose 50% (ED50) computed individual group levels. The group-level fitted ED50 24.60 lux, indicating that system is highly sensitive typical indoor Light 10, 30, 50 resulted later apparent onsets 22, 77, 109 min, respectively. Individual-level values ranged over an order magnitude (6 most individual, 350 least individual), with 26% coefficient variation. These findings demonstrate same evening-light environment registered very differently between individuals. This interindividual variability may be important factor determining clock's role human health disease.

Language: Английский

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Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adults

PLoS Biology, Journal Year: 2022, Volume and Issue: 20(3), P. e3001571 - e3001571

Published: March 17, 2022

Ocular light exposure has important influences on human health and well-being through modulation of circadian rhythms sleep, as well neuroendocrine cognitive functions. Prevailing patterns do not optimally engage these actions for many individuals, but advances in our understanding the underpinning mechanisms emerging lighting technologies now present opportunities to adjust promote optimal physical mental performance. A newly developed, international standard provides a SI-compliant way quantifying influence intrinsically photosensitive, melanopsin-expressing, retinal neurons that mediate effects. The report recommendations lighting, based an expert scientific consensus expressed easily measured quantity (melanopic equivalent daylight illuminance (melaponic EDI)) defined within this standard. are supported by detailed analysis sensitivity circadian, neuroendocrine, alerting responses ocular provide straightforward framework inform design practice.

Language: Английский

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Melanopic illuminance defines the magnitude of human circadian light responses under a wide range of conditions

Journal of Pineal Research, Journal Year: 2020, Volume and Issue: 69(1)

Published: April 5, 2020

Abstract Ocular light drives a range of nonvisual responses in humans including suppression melatonin secretion and circadian phase resetting. These are driven by intrinsically photosensitive retinal ganglion cells (ipRGCs) which combine intrinsic, melanopsin‐based, phototransduction with extrinsic rod/cone‐mediated signals. As result this arrangement, it has remained unclear how best to quantify predict its effects. To address this, we analysed data from nineteen different laboratory studies that measured suppression, resetting and/or alerting wide array stimulus types, intensities durations or without pupil dilation. Using newly established SI‐compliant metrics ipRGC‐influenced light, show melanopic illuminance consistently provides the available predictor for human system. In almost all cases, is able fully account differences sensitivity stimuli varying spectral composition, acting drive track variations illumination characteristic those encountered over civil twilight (~1‐1000 lux equivalent daylight illuminance). Collectively, our demonstrate widespread utility as metric predicting impact environmental illumination. therefore provide strong support use basis guidelines seek regulate exposure benefit health inform future lighting design.

Language: Английский

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Light Pollution, Circadian Photoreception, and Melatonin in Vertebrates

Sustainability, Journal Year: 2019, Volume and Issue: 11(22), P. 6400 - 6400

Published: Nov. 14, 2019

Artificial light at night (ALAN) is increasing exponentially worldwide, accelerated by the transition to new efficient lighting technologies. However, ALAN and resulting pollution can cause unintended physiological consequences. In vertebrates, production of melatonin—the “hormone darkness” a key player in circadian regulation—can be suppressed ALAN. this paper, we provide an overview research on melatonin vertebrates. We discuss how disrupts natural photic environments, its effect rhythms, different photoreceptor systems across vertebrate taxa. then present results systematic review which identified studies under typical light-polluted conditions fishes, amphibians, reptiles, birds, mammals, including humans. Melatonin extremely low intensities many ranging from 0.01–0.03 lx for fishes rodents 6 sensitive Even lower, wavelength-dependent are implied some require rigorous testing ecological contexts. studies, suppression occurs minimum levels tested, and, better-studied groups, reported occur lower levels. identify major gaps conclude that, most crucial information lacking. No were amphibians reptiles long-term impacts low-level exposure unknown. Given high sensitivity paucity available information, it further order inform effective mitigation strategies human health wellbeing fitness vertebrates ecosystems.

Language: Английский

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Smartphones in mental health: a critical review of background issues, current status and future concerns

International Journal of Bipolar Disorders, Journal Year: 2020, Volume and Issue: 8(1)

Published: Jan. 10, 2020

Abstract There has been increasing interest in the use of smartphone applications (apps) and other consumer technology mental health care for a number years. However, vision data from apps seamlessly returned to, integrated in, electronic medical record (EMR) to assist both psychiatrists patients not widely achieved, due part complex issues involved psychiatry. These include usage, clinical utility, commercialization, evolving technology. Technological, legal commercial issues, as well will determine role Recommendations more productive direction psychiatry are provided.

Language: Английский

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A Review of Human Physiological Responses to Light: Implications for the Development of Integrative Lighting Solutions

LEUKOS The Journal of the Illuminating Engineering Society of North America, Journal Year: 2021, Volume and Issue: 18(3), P. 387 - 414

Published: March 26, 2021

Architectural lighting has potent biological effects but applied practices that capitalize on this potential have been limited. In review, we endeavor to consolidate and synthesize key references will be useful for professionals, with the goal of supporting knowledge translation into pragmatic strategies. Specifically, explain relevant terminology, outline basic concepts, identify references, provide a balanced overview current state knowledge, highlight important remaining questions. We summarize physiological light human health well-being, including description processes underlying photic regulation circadian, neuroendocrine, neurobehavioral functions. review seminal work elucidating elements mediating potency these responses, specific attention factors critical interpreting those findings. parallel, endorse melanopic Equivalent Daylight Illuminance (Ev,melD65) as preferred measure quantify light. Ultimately, while future studies are necessary further facilitate laboratory domestic workplace settings, immediate better support is clear. Aiming integrative solutions biologically high during day low night perhaps most improvement made in order applications humans.

Language: Английский

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Individual differences in light sensitivity affect sleep and circadian rhythms

SLEEP, Journal Year: 2020, Volume and Issue: 44(2)

Published: Oct. 13, 2020

Abstract Artificial lighting is omnipresent in contemporary society with disruptive consequences for human sleep and circadian rhythms because of overexposure to light, particularly the evening/night hours. Recent evidence shows large individual variations photosensitivity, such as melatonin suppression, due artificial light exposure. Despite emerging body research indicating that effects on vary dramatically across individuals, recommendations appropriate exposure real-life settings rarely consider effects. This review addresses recently identified links among traits, example, age, sex, chronotype, genetic haplotypes, hallmarks, based laboratory field studies. Target biological mechanisms differences sensitivity include occurring within retina downstream, central clock. also highlights there are wide gaps uncertainty, despite growing awareness shape physiology. These (1) why do certain traits differentially affect influence rhythms; (2) what translational value populations typically exposed at night, night shift workers; (3) magnitude population-based studies? Collectively, current findings provide strong support considering when defining optimal specifications, thus allowing personalized solutions promote quality life health.

Language: Английский

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Melanopsin contributions to non-visual and visual function

Current Opinion in Behavioral Sciences, Journal Year: 2019, Volume and Issue: 30, P. 67 - 72

Published: July 27, 2019

Melanopsin is a short-wavelength-sensitive photopigment that was discovered only around 20 years ago. It expressed in the cell bodies and processes of subset retinal ganglion cells retina (the intrinsically photosensitive cells; ipRGCs), thereby allowing them to signal light even absence cone rod input. Many fundamental properties melanopsin signalling humans for both visual (e.g. detection, discrimination, brightness estimation) non-visual function melatonin suppression, circadian phase shifting) remain be elucidated. Here, we give an overview what know about contributions function.

Language: Английский

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Light Modulation of Human Clocks, Wake, and Sleep

Clocks & Sleep, Journal Year: 2019, Volume and Issue: 1(1), P. 193 - 208

Published: March 13, 2019

Light, through its non-imaging forming effects, plays a dominant role on myriad of physiological functions, including the human sleep-wake cycle. The non-image effects light heavily rely specific properties such as intensity, duration, timing, pattern, and wavelengths. Here, we address how influence sleep wakefulness in humans acute e.g., alertness, and/or circadian timing system. Of critical relevance, discuss different characteristics exposure across 24-h day can lead to changes propensity, architecture, wake electroencephalogram (EEG) power spectra. Ultimately, knowledge affects improve settings at home workplace health well-being optimize treatments chronobiological disorders.

Language: Английский

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Evening home lighting adversely impacts the circadian system and sleep

Scientific Reports, Journal Year: 2020, Volume and Issue: 10(1)

Published: Nov. 5, 2020

The regular rise and fall of the sun resulted in development 24-h rhythms virtually all organisms. In an evolutionary heartbeat, humans have taken control their light environment with electric light. Humans are highly sensitive to light, yet most people now use until bedtime. We evaluated impact modern home lighting environments relation sleep individual-level sensitivity using a new wearable spectrophotometer. found that nearly half homes had bright enough suppress melatonin by 50%, but wide range individual responses (0-87% suppression for average home). Greater evening relative individual's was associated increased wakefulness after Homes energy-efficient lights double melanopic illuminance incandescent lighting. These findings demonstrate significantly affects circadian system, specific is unpredictable.

Language: Английский

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