The post Sleep Disturbances, Circadian Activity and Nocturnal Light Exposure Characterize High Risk for and Current Depression in Adolescence appeared first on EMFSA.

Abstract

Declining female fertility has become a global health concern. It results partially from an abnormal circadian clock caused by unhealthy diet and sleep habits in modern life. The circadian clock system is a hierarchical network consisting of central and peripheral clocks. It not only controls the sleep–wake and feeding–fasting cycles but also coordinates and maintains the required reproductive activities in the body. Physiologically, the reproductive processes are governed by the hypothalamic–pituitary–gonadal (HPG) axis in a time-dependent manner. The HPG axis releases hormones, generates female characteristics, and achieves fertility. Conversely, an abnormal daily rhythm caused by aberrant clock genes or abnormal environmental stimuli contributes to disorders of the female reproductive system, such as polycystic ovarian syndrome and premature ovarian insufficiency. Therefore, breaking the “time code” of the female reproductive system is crucial. In this paper, we review the interplay between circadian clocks and the female reproductive system and present its regulatory principles, moving from normal physiology regulation to disease etiology.

Extract only, for the full study https://academic.oup.com/endo/article/162/8/bqab117/6298422

Remaining Questions and Future Direction

The normal routine of working at sunrise and resting at sunset has been gradually eroded in the social development process. Instead, high-intensity working patterns along with consequent eating and sleeping disorders and other “modern diseases” are becoming the main theme of daily life. Therefore, larger population studies are needed to characterize this remolding of the circadian rhythm. On this basis, chronobiology can help reverse poor physical conditions and improve existing treatment methods.

As early as 1994, the United Nations highlighted the importance of reproductive health in human development. The decline in female fertility resulting from abnormal circadian rhythms caused by unhealthy diet and sleep habits in modern life has become a global health concern (124, 125). Therefore, breaking the “time code” of the female reproductive system is an urgent task. Despite a large number of studies at present, most studies confine the role of a certain clock gene to a specific cell. As the female reproductive system is by no means a simple superposition of cells and tissues, future chronobiology studies are encouraged from a holistic perspective. Furthermore, constructing and improving the circadian clock network of the female reproductive system is needed to help determine biomarkers that could detect and diagnose circadian rhythm disturbances.

https://academic.oup.com/endo/article/162/8/bqab117/6298422

The post Circadian Rhythms Within the Female HPG Axis: From Physiology to Etiology appeared first on EMFSA.

Abstract

Background: Aortic aneurysm (AA) is a common atherosclerotic condition, accounting for nearly 6000 deaths in England and up to 175,000 deaths globally each year. The pathological outward bulging of the aorta typically results from atherosclerosis or hereditary connective tissue disorders. AAs are usually asymptomatic until spontaneous rupture or detected on incidental screening. Eight in 10 patients do not survive the rupture and die either before reaching hospital or from complications following surgery. Similar to other cardiovascular pathologies, AA is thought to be subject to chronobiological patterns of varying incidence.

Methods: We performed a literature review of the current literature to evaluate the association between circadian rhythms, seasonal variations, and genetic factors and the pathogenesis of AA, reviewing the impact of chronobiology.

Results: The incidence of AA is found to peak in the early morning (6-11 a.m.) and colder months, and conversely troughs towards the evening and warmer months, exhibiting a similar pattern of chronobiological rhythm as other cerebrovascular pathologies, such as myocardial infarcts, or cerebrovascular strokes.

Conclusion: Literature suggests there exists a clear relationship between chronobiology and the incidence and pathogenesis of ruptured AA; incidence increases in the morning (6-11 a.m.), and during colder months (December-January). This is more pronounced in patients with Marfan syndrome, or vitamin D deficiency. The underlying pathophysiology and implications this has for chronotherapeutics, are also discussed. Our review shows a clear need for further research into the chronotherapeutic approach to preventing ruptured AA in the journey towards precision medicine.

© 2021 Wiley Periodicals LLC.

https://pubmed.ncbi.nlm.nih.gov/33797793/

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Abstract

The intrinsic earth magnetic field (geomagnetic field, GMF) provides an essential environmental condition for most living organisms to adapt the solar cycle by rhythmically synchronizing physiological and behavioral processes. However, hypomagnetic field (HMF) of outer space, the Moon, and the Mars differs much from GMF, which poses a critical problem to astronauts during long-term interplanetary missions. Multiple experimental works have been devoted to the HMF effects on circadian rhythm and found that HMF perturbs circadian rhythms and profoundly contributes to health problems such as sleep disorders, altered metabolic as well as neurological diseases. By systemizing the latest progress on interdisciplinary cooperation between magnetobiology and chronobiology, this review sheds light on the health effects of HMF on circadian rhythms by elaborating the underlying circadian clock machinery and molecular processes.

Copyright © 2021 Xue, Ali, Luo, Liu, Zhou and Liu.

https://pubmed.ncbi.nlm.nih.gov/33767637/

The post Biological Effects of Space Hypomagnetic Environment on Circadian Rhythm appeared first on EMFSA.

Published: 21 September 2020

Abstract

Study Objectives

Blue-depleted lighting reduces the disruptive effects of evening artificial light on the circadian system in laboratory experiments, but this has not yet been shown in naturalistic settings. The aim of the current study was to test the effects of residing in an evening blue-depleted light environment on melatonin levels, sleep, neurocognitive arousal, sleepiness, and potential side effects.

Methods

The study was undertaken in a new psychiatric hospital unit where dynamic light sources were installed. All light sources in all rooms were blue-depleted in one half of the unit between 06:30 pm and 07:00 am (melanopic lux range: 7–21, melanopic equivalent daylight illuminance [M-EDI] range: 6–19, photopic lux range: 55–124), whereas the other had standard lighting (melanopic lux range: 30–70, M-EDI range: 27–63, photopic lux range: 64–136), but was otherwise identical. A total of 12 healthy adults resided for 5 days in each light environment (LE) in a randomized cross-over trial.

Results

Melatonin levels were less suppressed in the blue-depleted LE (15%) compared with the normal LE (45%; p = 0.011). Dim light melatonin onset was phase-advanced more (1:20 h) after residing in the blue-depleted LE than after the normal LE (0:46 h; p = 0.008). Total sleep time was 8.1 min longer (p = 0.032), rapid eye movement sleep 13.9 min longer (p < 0.001), and neurocognitive arousal was lower (p = 0.042) in the blue-depleted LE. There were no significant differences in subjective sleepiness (p = 0.16) or side effects (p = 0.09).

Conclusions

It is possible to create an evening LE that has an impact on the circadian system and sleep without serious side effects. This demonstrates the feasibility and potential benefits of designing buildings or hospital units according to chronobiological principles and provide a basis for studies in both nonclinical and clinical populations.

https://academic.oup.com/sleep/article/44/3/zsaa194/5909282

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Nutrients2020, 12(9), 2881; https://doi.org/10.3390/nu12092881 Received: 16 August 2020 / Revised: 11 September 2020 / Accepted: 15 September 2020 / Published: 21 September 2020(This article belongs to the Special Issue Meal Timing to Improve Human Health)

Abstract

Late eating has been shown to promote metabolic dysregulation and to be associated with obesity in adults. However, few studies have explored this association in children. We compared the presence of obesity, metabolic alterations and circadian-related disturbances between school-aged children who were early dinner eaters (EDE) or late dinner eaters (LDE). School-age children (n = 397; 8–12 years; mean BMI (range): 19.4 kg/m² (11.6–35.1); 30.5% overweight/obesity) from Spain were classified into EDE and LDE, according to dinner timing (Median: 21:07). Seven-day-dietary-records were used to assess food-timing and composition. Non-invasive tools were used to collect metabolic biomarkers (saliva), sleep and circadian-related variables (body-temperature and actigraphy). Compared to EDE, LDE were more likely to be overweight/obese [OR: 2.1 (CI: 1.33, 3.31); p = 0.002], and had higher waist-circumference and inflammatory markers, such as IL-6 (1.6-fold) (p = 0.036)) and CRP (1.4-fold) than EDE (p = 0.009). LDE had alterations in the daily patterns of: (a) body-temperature, with a phase delay of 26 min (p = 0.002), and a reduced amplitude (LDE = 0.028 (0.001) and EDE = 0.030 (0.001) (Mean (SEM); p = 0.039); (b) cortisol, with a reduced amplitude (LDE = 0.94 (0.02) and EDE = 1.00 (0.02); p = 0.035). This study represents a significant step towards the understanding of novel aspects in the timing of food intake in children.

The post Late Eating Is Associated with Obesity, Inflammatory Markers and Circadian-Related Disturbances in School-Aged Children appeared first on EMFSA.

The post Artificial Light, Chronobiology and LED Hazards appeared first on EMFSA.

Abstract

Exposure to light at inappropriate times in relation to the solar cycle can disturb circadian endocrine and metabolic rhythms. Previous studies have suggested an association between light exposure at night (LAN) and obesity, an important risk factor of atherosclerosis, although it remains unclear whether LAN associates with progression of atherosclerosis. To evaluate the longitudinal association between bedroom LAN intensity and progression of carotid atherosclerosis, light intensity in the bedroom at baseline and carotid artery intima-media thickness (IMT) at baseline and follow-up were measured in 989 elderly participants (945 at baseline and 780 at a median follow-up time of 34 months). The mean age of the participants was 71.4 ± 6.9 years. The average mean and maximal carotid IMT at baseline were 0.88 ± 0.15 and 1.10 ± 0.32 mm, respectively. The median intensity of bedroom LAN was 0.68 lx (IQR, 0.07–3.29). In multivariable analysis adjusted for potential confounders, the highest LAN group exhibited a significant increase in mean carotid IMT (adjusted β, 0.028; 95% CI, 0.005–0.052; P = 0.019) compared with the lowest LAN quartile group. A similar relationship was found between LAN and maximal carotid IMT (adjusted β, 0.083; 95% CI, 0.037–0.129; P < 0.001).

In conclusion, we found a clear and significant association between bedroom LAN intensity and progression of subclinical carotid atherosclerosis, which was independent of known risk factors for atherosclerosis, including age, obesity, smoking, economic status, hypertension, and diabetes. Indoor light pollution may be a potential risk factor for atherosclerosis in the general population.

https://www.sciencedirect.com/science/article/pii/S0160412019309432?via%3Dihub

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University of Groningen

This video paints the life and scientific contributions of Professor Serge Daan (1940-2018). Daan was an inspiring biologist with a broad interest in science. He started as professor at the University of Groningen in 1975. His publications were cited over 17,000 times and include seminal work in chronobiology, sleep research, psychiatry, physiology, ecology and behavioural biology. The ‘Two Process Model’ of human sleep regulation he developed with Alex Borbély and Domien Beersma, still inspires many sleep researchers all over the world. He was awarded several prizes and awards, including the prestigious International Prize for Biology, which he received from the Emperor of Japan.

Production: University of Groningen, Heddema Communications

For more about the life and work of Professor Serge Daan:

https://www.rug.nl/fse/research/daan_-prof.-serge

Prof Daan:

“In physics you ask how come?, in biology you ask how, but also why.”

“Biologists have the real experimental and analytical approaches.”

The post The life and contributions of Prof. Serge Daan, behavioural biologist appeared first on EMFSA.

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