Trial reportJournal of pineal research2020
Early chronotype with advanced activity rhythms and dim light melatonin onset in a rural population.
Trial report in Journal of pineal research, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers, 1 of them a synthesis that pooled it.
What it found
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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.
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.
Who cites it
12 citing papers in PubMed, 1 synthesis or guideline pooled it, 34 citations in OpenAlex.
- Evening types as determined by subjective and objective measures are more emotional eaters.Obesity (Silver Spring, Md.) · 2023Pooled it
- Association between dim light melatonin onset predicted from gene expression profiles with sleep time and chronotype preference: A pilot study.Chronobiology international · 2025Trial
- Are humans facing a sleep epidemic or enlightenment? Large-scale, industrial societies exhibit long, efficient sleep yet weak circadian function.Proceedings. Biological sciences · 2025Article
- Distribution of dim light melatonin offset (DLMOff) and phase relationship to waketime in healthy adults and associations with chronotype.Sleep health · 2024Article
- Behavioural Parameters of Circadian Rhythm Are Not Correlated with Dim Light Melatonin Onset: An Observational Study on Healthy Volunteers.Journal of clinical medicine · 2023Article
- Individual light history matters to deal with the Antarctic summer.Scientific reports · 2023Article
- Article
- Delayed circadian rhythms in older Africans living with human immunodeficiency virus (HIV).Journal of pineal research · 2023Article
- Sleep quality and neurohormonal and psychophysiological accompanying factors in adolescents with depressive disorders: study protocol.BJPsych open · 2022Article
- Sleep Under Preindustrial Conditions: What We Can Learn from It.Methods in molecular biology (Clifton, N.J.) · 2022Article
- Compared Heritability of Chronotype Instruments in a Single Population Sample.Journal of biological rhythms · 2021Article
- Evening preference correlates with regional brain volumes in the anterior occipital lobe.Chronobiology international · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
14 authors at 4 institutions in 3 countries.
Funding
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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Registered trials
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 Socratic graph.