Sleep and Biological Rhythms最新文献

[This corrects the article DOI: 10.1007/s41105-020-00262-0.].

Health effects of weekend catch-up sleep (CUS) could differ depending on both the ability to obtain sufficient sleep during weekdays and amount of weekend CUS required to compensate for sleep lost during the week. Using data from 3128 middle-aged (40-64 years) participants of the Sleep Heart Health Study, we examined the longitudinal association of these two aspects of sleep with all-cause mortality. CUS was calculated as the difference in self-reported habitual sleep duration between weekends and weekdays, and classified into no, short (1 h), and long (2 h or more) CUS. Polysomnography-measured total sleep time, representing the ability to obtain sufficient sleep, was classified into short (< 360 min) or normal (≥ 360 min) sleep durations. We estimated multivariable-adjusted mortality hazard ratios (HRs) and 95% confidence intervals (CIs) for six groups divided by the extent of CUS and sleep duration. Participants were followed up for a median (interquartile range) of 12.3 (11.3-13.5) years. Short weekend CUS with normal sleep duration was associated with lower mortality compared to no CUS with normal sleep duration (HR, 0.48; 95% CI 0.27-0.83). When stricter cutoffs were applied for sleep durations, while the protective effect of short CUS with normal sleep duration (≥ 390 min) was strengthened (HR, 0.36; 95% CI 0.17-0.78), the harmful effect of short CUS with short sleep duration (< 330 min) emerged (HR, 1.84; 95% CI 1.08-3.14). Results highlight the importance of balancing sleep ability and CUS. Sufficient sleep may reduce weekday sleep debt and only a short CUS would be required on weekends, improving mortality in middle-aged adults.

Supplementary information: The online version contains supplementary material available at 10.1007/s41105-023-00460-6.

This study aimed to answer the question of how media users will reallocate their sleep time when their main content channel changes from real-time broadcasting to selective viewing through the over-the-top (OTT) media streaming service. To draw a causal inference between OTT consumption and sleep patterns, the difference-in-difference (DID) estimation method was applied. With the DID approach, a clear distinction between treatment and control groups is essential because the main treatment effects can be screened by the compounding effects. While the conventional way of dividing two groups relies on the selection of limited variables, this study adopted random forest nearest-neighbor propensity score matching based on a machine learning algorithm to divide the two groups. This allows for meticulous matching of the two groups except for treatment. Results show that watching OTT late at night has a significant effect on reducing the total sleep duration on average by about 18-20 min (maximum about 30 min at 95% confidence level) and delaying bedtime by about 18 min (maximum about 26 min at 95% confidence level). This study showed that the selective viewing of content through OTT has the advantage of widening the range of content choices for media users and helping in arranging their time more autonomously, but watching content through OTT late at night leads to media users' departure from the existing sleep routine.

COVID-19 lockdowns can influence the sleep quality and daytime condition of patients with narcolepsy. Using data from our cohort study, we investigated changes in the quality of life and the symptom severity of patients with narcolepsy during Taiwan's 2021 lockdown and investigated differences by narcolepsy subtype, sex, and age. Patients with type 1 and type 2 narcolepsy (NT1 and NT2, respectively) aged 6-40 years were retrospectively recruited from our narcolepsy cohort study. These patients were regularly evaluated using the Short Form 36 Health Survey questionnaire (SF-36), the Epworth Sleepiness Scale (ESS), the visual analog scale (VAS) for hypersomnolence, the VAS for cataplexy and sleep diary. We compared the differences between the lockdown and the prelockdown periods by narcolepsy subtype, sex, and age. We used a paired t test analysis to compare differences in the SF-36, ESS, VAS scores and data of sleep diary between the prelockdown and lockdown periods (p1), and an independent t test analysis was used to compare the changes in different subgroups between the prelockdown and lockdown periods (p2). A total of 120 patients with narcolepsy were recruited (mean age 24.22 ± 6.87 years; 58% male); 80 of the patients had NT1 (mean age 25.25 ± 6.79 years; 60% male) and 40 had NT2 (mean age 22.16 ± 6.64, 53% male). During the lockdown period, the ESS score of total patients was decreased (p = 0.039) and body mass index was increased (p = 0.02). The NT1 group decreased significantly (p1 = 0.017), especially in men (p1 = 0.016) and adults (p1 = 0.04); scores for the VT domain of the SF-36 increased significantly in male and adult patients with NT2 (p1 = 0.048 and 0.012). Additionally, male patients with NT2 exhibited significantly decreased scores in the physical and emotional role functioning domains (p1 = 0.028, 0.024). The children and adolescents with NT1 had significantly decreased scores in the general health domain of the SF-36, but no significant change was noted in that of adults (p1 = 0.027, p2 = 0.012). We observed both negative and positive impacts of Taiwan's 2021 lockdown on patients with narcolepsy. A more flexible but structured daily routine with adequate sleep time should be considered for this population during lockdown and nonlockdown periods.

The beginning of the university brings together maturational, psychosocial and academic changes that make university students more prone to suffer from insufficient or poor quality sleep, which can negatively influence their academic performance. The period of taking exams is a key part of the academic year. However, there are few studies that analyze sleep during this period of time. Our aim is to study the association of sleep quality and sleep deprivation with academic performance during the examination period. A descriptive, cross-sectional and correlational study was carried out with the participation of 640 subjects in the first three years of five faculties belonging to the Universidad Autónoma de Madrid. The instrument used consisted of a questionnaire that included sociodemographic and academic data, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and information about the academic performance. During the examination period, a positive association was found between sleep quality and academic performance. University students slept less than desired, both on weekdays and weekends, and the sleep debt during the week was associated with a worse students' perception of their academic performance. In total, 61.3% of the students believed that their performance would improve by getting more sleep. In addition, low drowsiness and napping were also found. In conclusion, during periods of greater academic demand, an insufficient sleep and poor quality is commonly observed, affecting negatively to their academic performance. Actually, about 2/3 of our subjects believed that their performance would improve by getting more sleep.

Purpose: Obstructive sleep apnea (OSA) is associated with poorer executive function. This study examined the effects of a comprehensive exercise intervention on executive function in overweight adults with mild and moderate-to-severe OSA.

Methods: Participants aged between 30 and 65 years, with a body mass index (BMI) ranging from 27 to 42 kg/m^2, participated in a 6-week exercise program. Standardized polysomnographic recording methods provided total Apnea-Hypopnea Index (AHI) and level of hypoxemia. Executive function was assessed using the NIH Toolbox Flanker Inhibitory Control Test. A submaximal treadmill exercise test evaluated cardiorespiratory fitness. Participants with baseline total AHI between 5 and 14.9 events/h were classified as mild OSA and participants with baseline total AHI 15 ≥ events/h were classified as moderate-to-severe OSA.

Results: Fifteen participants completed 18 exercise sessions. Significant differences between OSA categories at baseline were observed for sleep characteristics, but not for fitness or executive function. Wilcoxon Signed Rank Tests showed significant increases in median values for the Flanker Test in the moderate-to-severe category only, z = 2.429, p < .015, η² = .737.

Conclusion: Six weeks of exercise improved executive function in overweight individuals with moderate-to-severe OSA, but not in those with mild OSA.

Purpose: The relationship between sleep and adiposity in older women remains unclear partly due to the reliance of body mass index as a measure of adiposity. The purpose of this study was to investigate associations between objectively measured sleep characteristics and body composition measured by dual energy x-ray absorptiometry (DXA) in older women. A secondary purpose was to examine if physical function mediates this relationship.

Methods: Non-obese older women (ages 60-75 years, n=102) were included in the study. Total sleep time (TST), time in bed (TIB), sleep efficiency (SE), and wake after sleep onset (WASO) were determined by actigraphy. A battery of tests was used to assess physical function.

Results: With adjustment for age, there was a negative association between TST and TIB with lean mass. Both grip strength and dominant leg extension were associated with TST, TIB, and lean mass; the associations between TST and TIB with lean mass were lost after adjusting for grip strength or leg extension strength. Additionally, SE was negatively associated with total, gynoid, and trunk lean mass, and there was a positive association between TST and percent trunk fat, and WASO and gynoid lean mass, with age adjusted.

Conclusions: Sleep characteristics, TST, TIB, SE, and WASO, were associated body composition measures in this sample of older women. The relationship between TST and TIB with body composition was mediated, in part, by grip strength and leg extension strength.

Sleep disorders affect more than one-quarter of the world's population, resulting in reduced daytime productivity, impaired immune function, and an increased risk of cardiovascular disease. It is important to identify the physiological and psychological factors related to sleep for the prevention and treatment of sleep disorders. In this study, we correlated measurements of emotional state, sleep quality, and some brain neural activity parameters to better understand the brain and psychological factors related to sleep. Resting-state functional magnetic resonance imaging (rs-fMRI) of 116 healthy undergraduates were analyzed using graph theory to assess regional topological characteristics. Among these, the left thalamic cluster coefficient proved to be the ablest to reflect the characteristics of the sleep neural graph index. The Profile of Mood States (POMS) was used to measure vigor, and the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. The results showed that the left thalamic clustering coefficient was negatively correlated with sleep quality and vigor. Further, the left thalamic clustering coefficient moderated the relationship between vigor and sleep quality. When the left thalamic clustering coefficient was very low, there was a significant positive correlation between vigor and sleep quality. However, when the left thalamic clustering coefficient was high, the correlation between vigor and sleep quality became insignificant. The relationship between vigor and sleep quality is heterogeneous. Analyzing the function of the left thalamic neural network could help understand the variation in the relationship between vigor and sleep quality in different populations. Such observations may help in the development of personalized interventions for sleep disorders.

The study was attempted to investigate the effect on and mechanisms of action of dexmedetomidine with regard to learning and memory impairment in rats with chronic rapid eye movement (REM) sleep deprivation. A total of 50 male Sprague Dawley rats were randomly divided into five groups. Modified multiple platform method was conducted to cause the sleep deprivation of rats. Dexmedetomidine and midazolam were administered by intraperitoneal injection. Learning and memory ability was assessed through Morris water maze. Morphological changes of rat hippocampal neurons and synaptic were detected by transmission electron microscope and Golgi staining. The gene expression in hippocampus of each group was detected by RNA-seq and verified by RT-PCR and western blot. REM Sleep-deprived rats exhibited spatial learning and memory deficits. Furthermore, there was decreased density of synaptic spinous in the hippocampal CA1 region of the sleep deprivation group compared with the control. Additionally, transmission electron microscopy showed that the synaptic gaps of hippocampal neurons in REM sleep deprivation group were loose and fuzzy. Interestingly, dexmedetomidine treatment normalized these events to control levels following REM sleep deprivation. Molecular biological methods showed that Alox15 expression increased significantly after REM sleep deprivation as compared to control, while dexmedetomidine administration reversed the expression of Alox15. Dexmedetomidine alleviated the spatial learning and memory dysfunction induced with chronic REM sleep deprivation in rats. This protective effect may be related to the down-regulation of Alox15 expression and thereby the enhancement of synaptic structural plasticity in the hippocampal CA1 area of rats.

Supplementary information: The online version contains supplementary material available at 10.1007/s41105-023-00450-8.