Search Results (250)

Morningness-eveningness is usually assessed as either a trait or a state using either a morning–evening preference scale or sleep timing reported for free days, respectively. These assessments were implemented in numerous studies exploring the associations between morningness-eveningness and health, mood, and sleep problems. Evening types almost always had more problems than morning types. We examined these associations in university students with conflicting results of trait and state assessments of morningness-eveningness and tried to confirm their chronotype using a multidimensional chronotyping approach that recognizes four types other than morning and evening (lethargic, vigilant, napping, and afternoon). The conflicting trait and state assessments of morningness-eveningness were found in 141 of 1582 students. Multidimensional chronotyping supported morningness of morning types with late weekend sleep timing, and the associations with health, mood, and sleep problems resembled the associations of other morning types (i.e., these associations persisted despite late sleep timing). In contrast, evening types with early weekend sleep timing were more likely classified as lethargic or napping types rather than evening types. They did not resemble evening types in their associations with health, mood, and sleep problems (i.e., early sleep timing did not change these associations). Model-based simulations of the sleep–wake cycles of students with conflicting trait and state assessments suggested that their bedtimes cannot be solely determined by their biological clocks. On weekdays or weekends, mind-bedtime procrastination can lead to missing the bedtime signal from their biological clocks (i.e., self-deprivation of sleep or, in other words, voluntary prolongation of the wake phase of the sleep–wake cycle). Full article

Glutamate and dopamine receptors play a crucial role in regulating synaptic plasticity throughout the sleep–wake cycle. These receptors form various heterocomplexes in synaptic areas; however, the role of this protein interactome in sleep–wake cycles remains unclear. Co-immunoprecipitation experiments were conducted to observe the complexation of the NMDA glutamate receptor (NMDAR) subunits GluN2A and GluN2B, metabotropic glutamate receptors mGluR1/5, and dopamine receptors (D1R and D2R) with the scaffold protein Homer in the synaptic membranes of the hippocampus after six hours of sleep deprivation (SD) in rats. Our findings indicate that the level of Homer in the GluN2A/mGluR1/D1R interactome decreased during SD, while the content of Homer remained unchanged in the GluN2B/mGluR1/D2R heterocomplex. Moreover, Homer immunoprecipitated a reduced amount of inositol trisphosphate receptor (IP3R) in the microsomal and synaptic fractions, confirming the dissociation of the ternary supercomplex Homer/mGluR1/IP3R during SD. Additionally, our findings indicate that SD increases the synaptic content of the AMPA receptor (AMPAR) subunit GluA1. Unlike AMPAR, NMDAR subunits in synaptic membranes do not undergo significant changes. Furthermore, the G-to-F actin ratio decreases during SD. Changes in the assembly of actin filaments occur due to the dephosphorylation of cofilin. These results suggest that SD causes the dissociation of the GluN2A/mGluR1/D1R/Homer/IP3R heterocomplex in synaptic and endoplasmic membranes. Full article

Sleep disorders, such as insomnia and narcolepsy, significantly impact quality of life. They are often associated with long-term health consequences, including cardiovascular disease, immune dysfunction, and cognitive impairment. While traditional treatments, such as sedatives and hypnotics, can be effective, they are limited by issues of tolerance and dependence. The orexinergic system, particularly the orexin 1 receptor (OXR1), has emerged as a promising therapeutic target due to its central role in regulating sleep–wake cycles. In this study, we investigate the molecular interactions of three OXR1 antagonists—daridorexant, lemborexant, and suvorexant—using an integrated computational approach combining molecular dynamics (MD) simulations, density functional theory (DFT) calculations, and the molecular fractionation with conjugate caps (MFCC) methodology. The MFCC approach enabled the precise quantification of interaction energies between ligands and key receptor residues, providing detailed insights into the contributions of specific amino acids to binding stability. Our results reveal that residues such as GLU204, HIS216, and ASN318 play critical roles in stabilizing ligand–receptor interactions, with a marked decrease in binding energy magnitude as dielectric constants increase. Daridorexant exhibited the strongest interaction energy, driven by hydrogen bonds and hydrophobic contacts, while lemborexant and suvorexant showed distinct stabilization patterns mediated by hydrophobic interactions. These findings provide a robust molecular basis for the rational design of next-generation OXR1 antagonists with improved efficacy and safety profiles. By elucidating drug–receptor interactions at the atomic level, this research underscores the impact of integrated computational approaches in drug discovery. It supports the development of precise targeted therapies for sleep disorders. Full article

Background/Objectives: Sleep and recovery are critical for optimising exercise performance. However, the efficacy of melatonin supplementation in improving sleep quality and next-day physical performance remains unclear. This study examined the effects of melatonin ingestion on sleep and performance-related outcomes the following day in trained males. Methods: In a randomised, double-blind, placebo-controlled crossover study, 12 trained males (age: 21.92 ± 2.84 years) ingested 6 mg of melatonin (MEL) or a placebo (PLA) the night before performing the 5 m shuttle test (5mSRT). Before and after the 5mSRT, blood samples were collected. Peak heart rate (HR_peak) and rating of perceived exertion (RPE) were recorded throughout the test. Perceived recovery status (PRS) and delayed onset muscle soreness (DOMS) were measured before, 5 min, 24 h, 48 h, and 72 h after the test. The sleep/wake cycle was monitored during the night after ingestion. Results: Data were analysed using paired t-tests, Wilcoxon tests, and two-way ANOVAs, with significance set at p < 0.05. Compared to PLA, MEL did not modify any sleep parameters or blood markers (all p > 0.05). However, MEL improved total distance, fatigue index, the percentage decrement between sprints, and HR_peak (all p < 0.05) in the 5mSRT compared to PLA. MEL also enhanced PRS values up to 72 h post-exercise and reduced DOMS (all p < 0.05). Conclusion: In summary, 6 mg of melatonin taken at night enhanced next-day high-intensity exercise performance and improved perceived recovery up to 72 h post-exercise. Full article

We introduce a novel system for automatic assessment of newborn and preterm infant behavior—including activity levels, behavioral states, and sleep–wake cycles—in clinical settings for streamlining care and minimizing healthcare professionals’ workload. While vital signs are routinely monitored, the previously mentioned assessments require labor-intensive direct observation. Research so far has already introduced non- and minimally invasive solutions. However, we developed a system that automatizes the preceding evaluations in a non-contact way using deep learning algorithms. In this work, we provide a Gated Recurrent Unit (GRU)-stack-based solution that works on a dynamic feature set generated by computer vision methods from the cameras’ video feed and patient monitor to classify the activity phases of infants adapted from the NIDCAP (Newborn Individualized Developmental Care Program) scale. We also show how pulse rate variability (PRV) data could improve the performance of the classification. The network was trained and evaluated on our own database of 108 h collected at the Neonatal Intensive Care Unit, Dept. of Neonatology of Pediatrics, Semmelweis University, Budapest, Hungary. Full article

Objective: The development of a normal sleep–wake rhythm in the first weeks of life depends on the physiological sensory needs of the newborn as well as the environment surrounding them. This includes, for example, avoiding pain, exposure to bright light at night and high noise levels. In high-risk newborns, this process can be influenced by immaturity of the central and peripheral nervous systems, therapeutic strategies and the work organization of an intensive care unit. Methods: This study used a narrative review to examine the literature on the interrelationship of sensory modalities on sleep–wake behavior in the context of neonatal intensive care. The current Cochrane reviews on cycled lighting’s effect on premature infants’ circadian rhythm development and noise or sound management in the neonatal intensive care unit, as well as the World Health Organization (WHO) global position paper on kangaroo mother care, were included. Results: An extensive body of literature relates to fetal and neonatal development of the five sensory modalities: touch, taste, smell, hearing and sight. In contrast, there is a lack of evidence regarding the choice of optimal lighting and suitable measures for noise reduction. Since 2023, the WHO has recommended that, from the moment of birth, every “small and sick” newborn should remain in skin-to-skin contact (SSC) with their mother. Developmental support pursues a multimodal approach with the goal of fostering early parent–child bonding, including the child’s needs and environmental conditions. Discussion: The implementation of early SSC and attention to the sleep–wake cycle require systemic changes in both the obstetric and neonatal settings to ensure seamless perinatal management and subsequent neonatal intensive care. Since there is a lack of evidence on the optimal sensory environment, well-designed, well-conducted and fully reported randomized controlled trials are needed that analyze short-term effects and long-term neurodevelopmental outcomes. Full article

Background/Objectives: Chronic rhinosinusitis (CRS) is a persistent inflammatory condition of the sinonasal mucosa lasting for at least three months. For patients, CRS-related sleep disturbances can significantly disrupt circadian rhythms, leading to further health complications such as cognitive impairment. Despite the well-documented sleep disturbances associated with CRS, there is limited research on objective assessment methods. Additionally, the severity of these issues can vary among patients. This study aims to assess sleep quality and timing in CRS patients and investigate their impact on cognition, providing guidance for personalized and tailored assessment and management of CRS. Methods: Our case–control study compares sleep patterns and cognitive function between CRS patients and healthy controls utilizing actigraphy, a non-invasive device for measuring sleep–wake cycles and circadian rhythms. The actigraphy-derived sleep variables include inter-daily variability, intra-daily variability, highest 10 h activity (M10), lowest 5 h activity (L5), relative amplitude (RA), sleep onset latency, sleep efficiency, sleep and wake time, time spent in bed, total sleep time, and wakefulness after sleep onset. We also used a standard questionnaire assessing sleep quality, the Pittsburgh Sleep Quality Index (PSQI). Results: Our study enrolled 44 CRS and 43 control participants. Our findings indicate that the actigraphy-derived sleep variables were comparable between groups, all with a p-value > 0.05. However, CRS patients exhibited greater early morning activity and significantly lower PSQI-reported sleep quality compared to controls (8.78 ± 3.45, 4.71 ± 2.96, respectively; adjusted p < 0.001). Actigraphy-derived sleep variables showed trends towards significance in association with episodic memory (p = 0.051) and executive function (p = 0.15). Conclusions: Actigraphy-derived sleep outcomes revealed associations with episodic and executive function, underscoring the potential of actigraphy in understanding the individualized sleep-related cognitive impacts in CRS patients. This highlights the importance of personalized assessment and management strategies to address the unique sleep and cognitive challenges faced by each patient. Full article

Background and Objectives: Shift work and night work are common among emergency physicians. It is necessary to provide continuous care to patients, especially with acute diseases, including throughout the night. Literature studies show that shift and night workers have an altered light exposure, timing of sleep and intake of food. The consequence of this desynchronization with the biological clock can lead these workers to be more exposed to developing some acute and chronic health conditions. In particular, the alteration of the sleep–wake cycle, fatigue, the shortened sleep duration and the misalignment of the body’s hormone production is a codified risk factor of gut dysbiosis that can lead to acute and chronic diseases, also gastrointestinal ones. the aim of this narrative review is to collect and summarize evidence about the association between the disruption of the circadian rhythm, sleep and food timing alterations, gut dysbiosis and the risk of gastrointestinal diseases among shift and night workers. Materials and Methods: we searched for evidence about the association of shift and night work, dysbiosis, gut microbiota and gastrointestinal diseases among shift workers in healthcare settings. Results: shift work and night work are associated with a higher risk of diseases, an inflammatory state and the alteration of the gut microbiota composition; but definitive data are still inconsistent. Conclusions: Until now, obtaining conclusive results in regard to the relationship between shift work, the gut microbiota and the increased risk of gastrointestinal disorders has been particularly complex and not yet feasible. More confirmatory studies are needed to better characterize risk factors and realize preventive measures. Full article

The sleep–wake rhythm, regulated by the suprachiasmatic nucleus (SCN) and peripheral clocks, is influenced by light, nutrition, stress, and exercise. Recent findings suggest that estrogen receptors in the SCN may link ovarian hormone regulation to circadian rhythms, highlighting the need to consider hormonal fluctuations throughout the menstrual cycle when examining the effects of exercise on the sleep–wake rhythm in females. Therefore, we conducted a scoping review to compile existing studies involving human participants, aiming to provide a foundation for research focused on the specific physiological phenomena in females. Based on 228 literature sources, only 6 met the inclusion criteria. Despite variations in the exercise type, intensity, and duration, transient exercise demonstrated a significant impact on the expression of the clock genes BMAL1, PER2, and CRY1, suggesting their susceptibility to such activities. This review highlights the absence of studies examining the effects of exercise on clock gene expression in females, particularly in relation to menstrual cycles and ovarian hormone fluctuations, emphasizing the need for future investigations that incorporate these factors. Full article

Background/Objectives: Primary insomnia is characterized by persistent sleeplessness that is not caused by medical, psychological, or environmental factors. It is defined by difficulty initiating or maintaining sleep for at least one month, leading to significant distress or impairment in daily functioning. This randomized, crossover, double-blind, placebo-controlled clinical trial aimed to assess the efficacy and tolerability of a Scutellaria lateriflora L. extract-based food supplement in subjects with mild to moderate primary insomnia. Methods: A total of 66 participants, aged 18–70 years, were randomly allocated into two groups (1:1 allocation ratio) and received either the food supplement (400 mg/day) or a placebo for 56 days, separated by a 28-day washout period. The clinical effectiveness of the food supplement was assessed using the Pittsburgh Sleep Quality Index (PSQI) as the primary outcome measure. Secondary outcomes included sleep-wake cycle parameters (sleep onset latency, sleep efficiency, and total sleep time) and a Visual Analog Scale (VAS). Results: A significant improvement in sleep-wake balance following supplementation with S. lateriflora, as reflected by enhanced scores in both primary and secondary outcomes, was observed. Furthermore, none of the participants reported adverse effects from the food supplement. Conclusions: Overall, these findings suggest that a S. lateriflora extract-based food supplement is a safe and effective strategy for restoring the sleep-wake cycle and improving quality of life in individuals with primary insomnia. Full article

Artificial light exposure, particularly from blue-rich sources, has raised concerns about its impact on sleep and circadian rhythms. While blue light’s effects are well-documented, the comparative impact of longer wavelengths, such as orange light (590–635 nm), remains underexplored. This study investigated the effects of 8 h blue (470–490 nm) and orange light exposures (500 lux) on sleep architecture in the next consecutive three days in Sprague-Dawley rats during the light or dark phase of a 12:12 h light–dark cycle. Sleep–wake states were assessed via electroencephalography (EEG) over 72 h. Blue light during the light period suppressed rapid eye movement (REM) sleep acutely and enhanced non-NREM sleep on Days 2 and 3. Orange light during the light period induced no immediate changes but increased NREM sleep on Day 2 with a biphasic REM response—suppression followed by rebound—persisting into Day 3. Blue light during the dark period increased NREM sleep during exposure, followed by suppression in the subsequent light period, with effects normalizing by Day 2. Blue light exposure suppressed melatonin levels compared to controls. These findings highlight spectral and temporal influences on sleep, with blue light exerting stronger acute effects and orange light eliciting delayed, biphasic responses. The results suggest implications for managing light exposure to mitigate sleep disruptions in modern environments. Full article

Trail running has seen a surge in participants, including individuals with disabilities, particularly in ultratrail running (UTRs). Sleep–wake patterns are crucial for optimal performances in UTRs, which present unique physiological and behavioral challenges. This case study evaluated the sleep–wake cycle of a blind trail ultramarathoner (BTR) and his guide (GTR) before, during, and after an 80 km UTR. Two male participants (BTR: 54 years, BMI: 26.1 kg/m²; GTR: 48 years, BMI: 24.2 kg/m²) were assessed using validated questionnaires (MEQ, ESS, ISI, and PSQI) and actigraphy over 35 days. The BTR exhibited a morning chronotype (MEQ = 63), mild insomnia (ISI = 11), poor sleep quality (PSQI = 5), and prolonged sleep latency (>60 min), while the GTR showed an indifferent chronotype (MEQ = 52), good sleep quality (PSQI = 3), and shorter latency (10 min). Post-competition, both athletes experienced an increased total sleep time (TST): the BTR by 17.8% (05:32:00 vs. 04:25:00) and the GTR by 5.5% (07:01:00 vs. 06:39:00). The BTR demonstrated a greater Wakefulness after sleep onset (WASO 01:00:00 vs. 00:49:00) and awakenings (15.4 vs. 6.1). A time series analysis revealed greater variability in the BTR’s post-competition sleep efficiency and TST, while the GTR exhibited a greater stability of the circadian phase. These findings highlight the intricate sleep challenges faced by blind athletes, informing strategies to optimize recovery and performance. Full article

Many females experience physical problems caused by menstruation, such as menstrual cramps and premenstrual syndrome, which disrupt their daily lives and work. Knowing when menstruation begins is essential for managing such physical conditions. However, menstrual periods are not always cyclic and can be extended by physical and mental stress. Currently used menstrual management applications rely on self-reported cycle length and basal body temperature (BBT), which makes it challenging to predict irregular periods. Advances in smart wearables have made continuous, non-invasive health monitoring accessible, such as heart rate variability (HRV). HRV characteristics reflect autonomic nervous system activity and are used as physical and mental health status indices. This study aims to explore the relationship between HRV indices and the menstrual cycle using smart wearables. A total of 13 females aged from 18 to 20 participated in this study and measured their indices using an underwear-type wearable device for six months. The device measured HRV and body acceleration. Participants recorded their BBT every morning and answered questionnaires about their physical and mental status every morning and evening. They also reported the start and end dates of menstruation. The HRV data were split into sleep and wake phases using acceleration and calculated time- and frequency-domain HRV indices. Cross-correlation and regression analysis were conducted to assess the relation between the menstrual cycle and phases, such as follicular and luteal, and the HRV indices. A significant relationship between HRV indices and the menstrual cycle length was found, particularly in the difference between the follicular and luteal phases of HRV indices. This difference showed a relatively high association with menstrual cycle length. Importantly, the regression analysis results suggested that HRV indices can be used to predict the length of the menstrual cycle and potential physical and mental disorders. These findings significantly contributed to menstrual health management and the Femtech industry. Full article

This study aimed to examine the influence of training load, performance, sleep, and menstrual parameters on heart rate variability (HRV) and to evaluate its potential as a predictor of sports performance. A four-year longitudinal case study was conducted on a female elite kayak athlete, involving daily monitoring of HRV, sleep quality and duration, menstrual cycles, illnesses, and acute training loads. Over this period, 1394 measurements were taken each morning immediately after waking up and before getting up. The results of four competitive seasons were analyzed using a performance index and were statistically processed with a linear mixed model. The analysis revealed a statistically significant positive association between rMSSD and both sleep quality (p < 0.001) and the follicular phase of the menstrual cycle (p = 0.003). In contrast, the training load (p = 0.94), sleep duration (p = 0.27), and illness (p > 0.05) showed no statistically significant effect on rMSSD. Additionally, neither rMSSD (p = 0.82) nor its trend (p = 0.70) were significant predictors of the performance index. Despite the lack of a statistically significant correlation between HRV and sports performance, the findings suggest that the pre-competition decrease in HRV observed in this case study may reflect anticipatory physiological changes, potentially linked to increased sympathetic activation, as suggested in the existing literature. Full article

Ageing is associated with alterations in circadian rhythms and thermoregulation, contributing to a fragmentation of the sleep–wake cycle and possibly age-related changes in cognitive performance. In this study, we investigated the relationship between visuo-spatial working memory (vsWM) performance and thermoregulation in young (18–34 years) and old (64–84 years) healthy human adults. Variations in the distal–proximal skin temperature gradient (DPG) were continuously monitored over the 24 h cycle in a field setting. vsWM was assessed during morning (09:00) and evening sessions (17:00) using an object–location binding task. As expected, a reduced circadian DPG amplitude was observed in old as compared to young participants. Likewise, old participants produced more errors than the young ones in object identification and location, suggesting reduced vsWM ability. Notwithstanding this, no significant association was found between circadian DPG modulation and vsWM performance, nor between testing time-of-day and cognitive performance. Further research is needed to explore environmental factors and the timing of peak circadian rhythms to better understand the interplay between circadian biology and cognitive ageing. Full article