Clocks & Sleep最新文献

Physical activity (PA) programs have been found to result in improved sleep in males with autism spectrum disorder (ASD), but little is known about the female characteristics. The aim of this work was to assess sex differences in sleep and PA indices using an accelerometer over 7 days and 7 nights. Sleep and PA variables were measured with questionnaires and with accelerometry in twenty-four children with ASD (16 boys, 10.3 ± 2.8; 8 girls, 11.1 ± 3.9). Some significant differences were reported between girls and boys. The total time in bed and wake time after sleep onset (WASO) were significantly higher in girls compared to boys (p < 0.01), whereas sleep efficiency was significantly lower in girls (p < 0.01). The results obtained from the sleep questionnaire (CSHQ) show averages above the threshold of 41 in both groups (the threshold indicates the presence of sleep disorders or low sleep quality). The number of daily steps was significantly lower in the girls' group (p < 0.01), and the PA volume for vigorous and strong vigorous intensities was significantly higher in the boys' group (p < 0.01 and p < 0.05, respectively). Our results show major alterations in girls, with a low level of PA and sleep alteration. PA is a relevant non-pharmacological approach to improve sleep quality and achieve sufficient sleep duration. However, particularly for girls with ASD, more personalized approaches to improve sleep may be needed to manage specific associated disorders.

The effect of caffeine on the behavior and sleep patterns of zebrafish larvae, as well as its underlying mechanisms, has been a topic of great interest. This study aimed to investigate the impact of caffeine on zebrafish larval sleep/wake behavior and the expression of key regulatory genes such as cAMP-response element binding protein (CREB) and adenosine (ADA) in the sleep pathway. To begin, the study determined the optimal dose and duration of caffeine exposure, with the optimal doses found to be 31.25 μM, 62.5 μM, and 120 μM. Similarly, the optimal exposure time was established as no more than 120 h, ensuring a mortality rate of less than 10%. The confirmation of these conditions was achieved through the assessment of angiogenesis and the inflammatory reaction. As a result, the treatment time point of 24 h post-fertilization (hpf) was selected to examine the effects of caffeine on zebrafish larval sleep rhythm (48 h, with a light cycle of 14:10). Furthermore, the study analyzed the expression of clock genes (bmal1a, per1b, per2, per3, cry2), adenosine receptor genes (adora1a, adora1b, adora2aa, adora2ab, adora2b), and key regulatory factors (CREB and ADA). The research confirmed that caffeine could induce sleep pattern disorders, significantly upregulate adenosine receptor genes (adora1a, adora1b, adora2a, adora2ab, adora2b) (p < 0.05), and markedly decrease the total sleep time and sleep efficiency of the larvae. Additionally, the activity of ADA significantly increased during the exposure (p < 0.001), and the tissue-specific expression of CREB was also significantly increased, as assessed by immunofluorescence. Caffeine may regulate circadian clock genes through the ADA/ADORA/CREB pathway. These findings not only enhance our understanding of the effects of caffeine on zebrafish larvae but also provide valuable insights into the potential impact of caffeine on human behavior and sleep.

I am delighted to introduce this collection of abstracts from our recent 35th Annual SLTBR Meeting in Prague [...].

Background: Several environmental factors affect sleep. We investigated the sleep and sleep-related habits of preschool children living in Tibet and conducted an international comparison with those in Japan.

Methods: We conducted a community-based cross-sectional study using the Chinese version of the Japanese Sleep Questionnaire for Preschoolers (JSQ-P-C) and compared the results with previous data on Japanese children.

Results: The sleep status of 3113 children aged 3-6 years old in Qinghai province was evaluated. The average wake time and bedtime of the Tibetan children were 7:20 ± 0:31 and 21:16 ± 0:43, respectively. Their mean nocturnal sleep duration was 10.0 ± 0.7 h. In comparing 3-year-old children, the time for which they viewed TV in Tibet was shorter (65.5 ± 44.6 min) than that in Japan (149.7 ± 76.6 min), and the mother's bedtime was earlier in Tibet (21:28 ± 2:14) than in Japan (23:20 ± 1:05). However, the bedtime and sleep duration of the Tibetan children (21:17 ± 0:37 and 10.0 ± 0.7 h) were fairly similar to those of the Japanese children (21:24 ± 1:57 and 9.8 ± 0.8 h).

Conclusions: The late bedtime and short nocturnal sleep duration of Tibetan toddlers were the same as those of Japanese toddlers despite considerable differences in their lifestyle and environment.

In this study, we investigated the sleep-wake rhythm of nursery school children with the aim of supporting their health and mental/physical development. We analyzed 4881 children from infancy to 6 years of age, using 2 week sleep tables recorded by their guardians. The tables contained night bedtimes, wake times, nighttime/daytime sleep duration, and the differences in these between weekdays and weekends. The total sleep decrement of children with increasing age is attributed to a decrease in daytime sleep, while nighttime sleep duration remains almost unchanged at about 10 h, which is, therefore, referred to as the nighttime basic sleep duration (NBSD). Although bedtime stabilizes at around 9:30 p.m. by the age of 2, wake-up times tend to be before 7 a.m., which results in sleep insufficiency during weekdays. This lack of sleep is compensated for by long naps on weekdays and by catching up on sleep on weekend mornings, which may contribute to future social jet lag. Guardians are encouraged to know their children's exact NBSD and set an appropriate bedtime to be maintained on weekdays. This helps to prevent sleep debt and fosters a consistent daily rhythm of waking up at the same time both on weekdays and weekends. These conditions are believed to support mental/physical development and school and social adaptation.

The need for sleep is universal, and the ability to meet this need impacts the quality of life for patients, families, and caregivers. Although substantial progress has been made in treating rare diseases, many patients have unmet medical sleep needs, and current regulatory policy makes it prohibitively difficult to address those needs medically. This opinion reviews the rare disease experience with sleep disorders and explores potential solutions. First, we provide case profiles for the rare diseases Wilson's Disease, Angelman Syndrome, and Prader-Willi Syndrome. These profiles highlight challenges in rare disease diagnosis and barriers to pinpointing disease pathophysiology, including biomarkers that intersect with sleep disorders. Second, we transition to a bird's eye view of sleep disorders and rare diseases by reporting input from a stakeholder discussion with the U.S. Food and Drug Administration regarding abnormal sleep patterns in various rare diseases. Last, in response to the profound unmet medical needs of patients with rare diseases and sleep disorders, we propose adapting and using the clinical trial design known as a "basket trial". In this case, a basket trial would include patients with different rare diseases but the same debilitating symptoms. This research approach has the potential to benefit many rare disease patients who are otherwise left with profound unmet medical needs.

In many medical settings, medications are typically administered in the morning or evening, aligning with patients' daily routines. This practice does not stem from chronotherapy, which involves scheduling drug administration to enhance its effectiveness, but rather from the way clinical operations are structured. The timing of drug administration can significantly affect a medication's effectiveness and side effects, with the impact varying by up to ten times based on circadian rhythms. Disorders such as major depression, bipolar disorder, and schizophrenia are linked to disruptions in these rhythms. Recent studies have found that circadian dysfunctions, including genetic and neurohumoral changes, underlie many psychiatric conditions. Issues such as an altered glucocorticoid rhythm due to impaired HPA axis function, disturbed melatonin balance, and sleep disturbances have been noted in psychotic disorders. Furthermore, mood disorders have been associated with changes in the expression of circadian rhythm genes such as Clock, Bmal1, and Per. Considering that the absorption, biodistribution, effects on target organs, half-life, metabolism, and elimination of drugs are all influenced by the body's circadian rhythms, this narrative review explores the optimal timing of medication administration to maximize efficacy and minimize side effects in the treatment of psychiatric disorders. By closely monitoring circadian variations in cortisol, melatonin, and key clock genes, as well as by deepening our understanding of the metabolisms and pharmacokinetics of antipsychotic medications, we propose a chronotherapy approach for psychiatric patients that could significantly enhance patient care.

Understanding user challenges with light dosimeters is crucial for designing more acceptable devices and advancing light exposure research. We systematically evaluated the usability and acceptability of a light dosimeter (lido) with 29 participants who wore the dosimeter near the corneal plane of the eye for 5 days. Common reasons for not wearing the dosimeter included exercise, recharging, wet environments, public places, and discomfort. Despite these issues, participants adhered to using the dosimeter with high compliance (89% of recording time). Our findings revealed a significant discrepancy between mean (300 lx_mEDI) and median (51 lx_mEDI) melanopic equivalent daylight illuminance. This discrepancy indicates that the participants were exposed to significantly lower light levels most of the time. Specifically, participants were exposed to light levels above 250 lx_mEDI for only 14% of their wearing time. This highlights the need for increased exposure to recommended light levels. In the evening, participants were exposed to less than the recommended 10 lx_mEDI for 58% of their wearing time, which is in line with the guidelines for reducing light exposure before sleep. This study highlights the urgent need for strategies to increase daily light exposure that are more in line with circadian health recommendations.

Cognitive fatigue (CF) is a critical factor affecting performance and well-being. It can be altered in suboptimal sleep quality conditions, e.g., in patients suffering from obstructive sleep apnea who experience both intermittent hypoxia and sleep fragmentation (SF). Understanding the neurophysiological basis of SF in healthy individuals can provide insights to improve cognitive functioning in disrupted sleep conditions. In this electroencephalographical (EEG) study, we investigated in 16 healthy young participants the impact of experimentally induced SF on the neurophysiological correlates of CF measured before, during, and after practice on the TloadDback, a working memory task tailored to each individual's maximal cognitive resources. The participants spent three consecutive nights in the laboratory two times, once in an undisrupted sleep (UdS) condition and once in an SF condition induced by non-awakening auditory stimulations, counterbalanced and performed the TloadDback task both in a high (HCL) and a low (LCL) cognitive load condition. EEG activity was recorded during wakefulness in the 5 min resting state immediately before and after, as well as during the 16 min of the TloadDback task practice. In the high cognitive load under a sleep-fragmentation (HCL/SF) condition, high beta power increased during the TloadDback, indicating heightened cognitive effort, and the beta and alpha power increased in the post- vs. pre-task resting state, suggesting a relaxation rebound. In the low cognitive load/undisturbed sleep (LCL/UdS) condition, low beta activity increased, suggesting a relaxed focus, as well as mid beta activity associated with active thinking. These findings highlight the dynamic impact of SF on the neurophysiological correlates of CF and underscore the importance of sleep quality and continuity to maintain optimal cognitive functioning.

For centuries, epileptic seizures have been noticed to recur with temporal regularity, suggesting that an underlying biological rhythm may play a crucial role in their timing. In this review, we propose to adopt the framework of chronobiology to study the circadian timing of seizures. We first review observations made on seizure timing in patients with epilepsy and animal models of the disorder. We then present the existing chronobiology paradigm to disentangle intertwined circadian and sleep-wake timing mechanisms. In the light of this framework, we review the existing evidence for specific timing mechanisms in specific epilepsy syndromes and highlight that current knowledge is far from sufficient. We propose that individual seizure chronotypes may result from an interplay between independent timing mechanisms. We conclude with a research agenda to help solve the urgency of ticking seizures.