Evidence map›Paper›PMID 30340620›Full record

ArticleJournal of physiological anthropology2018

Suppression of salivary melatonin secretion under 100-Hz flickering and non-flickering blue light.

Tomoaki Kozaki, Yuki Hidaka, Jun-Ya Takakura, Yosuke Kusano

Open access · goldAbstract read
In one paragraph

Article in Journal of physiological anthropology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
7citing papers in PubMed, 1 pooled it
1.0field-weighted citation impact, top 26% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

7 citing papers in PubMed, 1 synthesis or guideline pooled it, 15 citations in OpenAlex.

  1. Melatonin-Measurement Methods and the Factors Modifying the Results. A Systematic Review of the Literature.International journal of environmental research and public health · 2020
    Pooled it
  2. Trial
  3. Article
  4. Blue Light-Ocular and Systemic Damaging Effects: A Narrative Review.International journal of molecular sciences · 2023
    Review
  5. Article
  6. Article
  7. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors at 4 institutions in 1 country.

Tomoaki KozakiDepartment of Environmental Science, International College of Arts and Sciences, Fukuoka Women's University, 1-1-1 Kasumigaoka, Higashi-ku, Fukuoka, 813-8529, Japan. kozaki@fwu.ac.jp.
Yuki HidakaFaculty of Design, Kyushu University, Fukuoka, Japan.
Jun-Ya TakakuraCenter for Social and Environmental Systems Research, National Institute for Environmental Studies, Tsukuba, Japan.
Yosuke KusanoDepartment of Health and Nutrition Sciences, Nishikyushu University, Kanzaki, Japan.
Fukuoka Women's University · JPKanzaki (Japan) · JPKyushu University · JPNational Institute for Environmental Studies · JP

Funding

Japan Society for the Promotion of Science 15H04431
6 · The paper itself

Abstract

backgroundBright light at night is known to suppress melatonin secretion. Novel photoreceptors named intrinsically photosensitive retinal ganglion cells (ipRGCs) are mainly responsible for projecting dark/bright information to the suprachiasmatic nucleus and thus regulating the circadian system. However, it has been shown that the amplitude of the electroretinogram of ipRGCs is considerably lower under flickering light at 100 Hz than at 1-5 Hz, suggesting that flickering light may also affect the circadian system. Therefore, in this study, we evaluated light-induced melatonin suppression under flickering and non-flickering light.

methodsTwelve male participants between the ages of 20 and 23 years (mean ± S.D. = 21.6 ± 1.5 years) were exposed to three light conditions (dim, 100-Hz flickering, and non-flickering blue light) from 1:00 A.M. to 2:30 A.M., and saliva samples were obtained just before 1:00 A.M. and at 1:15, 1:30, 2:00, and 2:30 A.M.

resultsA repeated measures t test with Bonferroni correction showed that at 1:15 A.M., melatonin concentrations were significantly lower following exposure to non-flickering light compared with dim light, whereas there was no significant difference between the dim and 100-Hz flickering light conditions. By contrast, after 1:30 A.M., the mean melatonin concentrations were significantly lower under both 100-Hz flickering and non-flickering light than under dim light.

conclusionAlthough melatonin suppression rate tended to be lower under 100-Hz flickering light than under non-flickering light at the initial 15 min of the light exposure, the present study suggests that 100-Hz flickering light may have the same impact on melatonin secretion as non-flickering light.

Indexed as

LightAdultCircadian RhythmHumansMaleMelatoninSalivaYoung AdultMelatonin

Identifiers

PMID30340620
PMCPMC6194675
OpenAlexW2897031694

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.