Midday Nap Research Articles

Association between nighttime sleep duration, nap time, and mild cognitive impairment in Chinese older adults: a cross-sectional study

ObjectiveThis study aims to investigate the relationship between midday nap time, nighttime sleep duration, and mild cognitive impairment (MCI) in Chinese older adults and determine the recommended sleep duration to provide a scientific basis for preventing and managing MCI in this population.MethodsUtilizing the 2020 China Health and Retirement Longitudinal Study database, the demographic data, health status, and lifestyle information of the study participants were collected. A total of 5,314 valid samples were included in the analysis. Logistic regression and restricted cubic spline plots were employed to explore the relationship between sleep patterns and MCI.ResultsIn the cross-sectional analysis, a linear relationship was observed between midday nap duration and MCI among Chinese elderly. The probability of MCI was lowest among those who napped for less than 30 min at noon. Compared with individuals who napped for30-90 min, those who did not nap were more likely to have MCI (OR = 1.30, 95% CI: 1.05–1.60). Older adults with napping duration < 30 min (OR = 0.73, 95% CI:0.56–0.95) also exhibited lower probability of MCI when compared those without napping habit, Nighttime sleep duration exhibited a U-shaped relationship with MCI. Individuals with less than approximately 6 h of nighttime sleep showed a gradual decrease in the probability of MCI with increasing sleep duration, whereas those with more than 7.5 h demonstrated an increase in the probability of MCI with longer sleep duration. Older adults who slept less than 6 h at night (OR = 1.22, 95% CI: 1.01 ~ 1.46) or more than 8 h (OR = 1.78, 95% CI: 1.35–2.33) were more likely to develop MCI compared with those who slept 6 to 8 h.ConclusionAfter controlling for potential confounding variables, both nighttime sleep duration and midday nap duration exhibited a nonlinear “U”-shaped relationship with MCI among the elderly. The probability of depression was lower with a nap duration of approximately 60 min, and the optimal nighttime sleep duration was 6–8 h, with around 7 h providing the greatest cognitive benefits.

Habitual Nocturnal Sleep, Napping Behavior, and Recovery Following Training and Competition in Elite Water Polo: Sex-Related Effects.

To examine nocturnal sleep patterns, napping behaviors, and subjective wellness responses of elite water polo players within an in-season week and to identify whether sleeping patterns differ between men and women. Sleep characteristics of 10 male and 17 female professional water polo players were objectively assessed during 1week of the in-season period, including 5 training days, 1 match day, and 1day of rest. Internal load (rating of perceived exertion × duration of training or match) was assessed 30 minutes posttraining or postmatch, and the total quality of recovery was recorded every morning. A series of multilevel models were used to analyze the data. Time in bed and wake-up time were earlier on both training (P < .001) and rest days (P < .001) than on the day of the match. Internal workload did not predict any of the players' sleeping patterns. Midday naps predicted less time in bed (P = .03) and likely less sleep time (P = .08). The total quality of recovery was predicted only by the total sleep time (P < .01). Women exhibited higher sleep efficiency (P < .001), less waking after sleep onset (P = .01), and a lower number of awakenings (P = .02) than men. The current results indicate that the nocturnal sleep patterns of elite water polo players are not associated with internal load and that women display better nocturnal sleep quality compared with men. As long naps interfere with nocturnal sleep, and total nocturnal sleep time predicts total quality of recovery, we suggest that athletes follow hygiene sleep strategies to facilitate adequate nocturnal sleep and next-day recovery.

A nap consolidates generalized perceptual learning

Previous research has demonstrated that a night's sleep can consolidate rote and generalized perceptual learning. Over a waking retention period following training, performance gains from learning significantly decline, but sleep can restore performance to levels found immediately after learning. Furthermore, when sleep precedes a waking retention period following training, performance is protected against loss. Other research demonstrating that rote learning can be consolidated by a night's sleep has shown that a relatively brief nap can consolidate rote learning. This suggests that short periods of sleep can produce consolidation, indicating that consolidation may not require successive sleep cycles over an entire night to emerge. However, previous research has demonstrated that there can be differences in sleep-dependent consolidation for rote and generalized learning. In this study, we investigated whether an opportunity for a 90-min midday nap was sufficient to consolidate generalized perceptual learning of synthetic speech. We recruited 75 participants from the University of Chicago community (mean age of 20.83) who completed a pretest, training, and posttest in the morning on perception of synthetic speech. Training and testing in this manner are known to result in substantial generalized learning of synthetic speech. Participants then returned in the afternoon and were either given an opportunity for a 90-min nap or remained awake for 90-min. Participants were then given another posttest later that evening, never hearing the same words twice during the experiment. Results demonstrated that participants who did not nap showed significant loss of learning at the evening posttest. In contrast, individuals who napped retained what they learned, and did not show loss of learning at the evening posttest. These results are consistent with the view that an opportunity for a 90-min midday nap can consolidate generalized learning, as only individuals with consolidated learning should be able to retain what they learned despite an intervening waking retention period. This is the first demonstration that generalized skill learning is subject to sleep-dependent consolidation in short durations of sleep and does not require a full night of sleep. This work has implications for understanding the basic neural mechanisms that operate to stabilize short-term learning experiences.

Disparities in sleep-wake patterns by labor force status: Population-based findings

ABSTRACT Sleep disturbances have been associated with unemployment, but variation in sleep-wake patterns by labor force status has rarely been examined. With a population-based sample, we investigated differences in sleep-wake patterns by labor force status (employed, unemployed, and not-in-the-labor-force) and potential disparities by sociodemographic variables. The analysis included 130,602 adults aged 25–60 y, who participated in the American Time Use Survey between 2003 and 2019. Individual sleep-wake pattern was extracted from time use logs in a strict 24-h period (04:00 h–03:59 h). Functional nonparametric regression models based on dimensionality reduction and neighborhood matching were applied to model the relationship between sleep-wake patterns and labor force status. Specifically, we predicted changes in intra-person sleep-wake patterns under hypothetical changes of labor force status from employed to unemployed or not-in-the-labor-force. We then studied moderations of this association by gender, race/ethnicity and educational attainment. In comparison to the employed state, unemployed and not-in-the-labor-force states were predicted to have later wake-times, later bedtimes, and higher tendency for taking midday naps. Changes in labor force status led to more apparent shifts in wake-times than in bedtimes. Additionally, sleep schedules of Hispanics and those with higher education level were more vulnerable to the change of labor force status from employed to unemployed.

0069 Effects of Depression and Anxiety Symptoms on Sleep-Dependent Consolidation of Emotional Memory in College Students

Abstract Introduction Depression and anxiety have been associated with emotional memory biases, disturbed sleep, and cognitive deficits. The goal of the present study is to investigate the effects of elevated levels of depressive and anxiety symptoms on sleep physiology and sleep-dependent consolidation of emotional memory and reactivity over a mid-day nap in young college students. Methods Data collection is ongoing, preliminary analyses are based on 34 participants (26F, 7M, 1 non-binary, 18-27 yrs). Based on well-validated depression and anxiety scales, participants were classified into high (n=10) vs low (n=24) symptom groups. Participants studied negative and neutral picture stimuli and rated them on the dimensions of valence and arousal. Recognition memory was tested after a 5 hr interval which included a high-density EEG monitored 90 min nap. Results We do not observe any group differences in memory accuracy (d’) or in selectivity for emotional stimuli. In the entire sample, depressive symptoms correlate with decision criterion (C) for negative stimuli (r = -0.357, p=.04), such that individuals with higher depressive symptoms have a more liberal responding bias for negative stimuli. Napping is associated with a decrease in arousal ratings across all participants (F(1,32)=5.43, p=.03), and the high mood symptom group rate stimuli as more arousing (F(1,32)=13.96, p&amp;lt;.001). Further, high levels of trait anxiety is associated with more negative valence ratings post-nap (r = -0.350, p=.03). Conclusion The effects of a mid-day nap on memory consolidation and reactivity for emotional stimuli are similar between individuals with high vs low levels of mood symptoms, but heightened levels of depression and anxiety are associated with altered response bias and higher emotional reactivity. Future plans involve comparisons of NREM oscillations between groups and investigation of their relations with task performance. Support (if any) Iowa Neuroscience Institute “2021 Ideas Lab” Award (Baran)

Associations between sleep characteristics and risk for high blood pressure among students aged 9–18: A cross-sectional study in China

ObjectiveThe aim was to investigate the association of multidimensional sleep indicators with high blood pressure (HBP) of Chinese students. MethodsParticipants in this cross-sectional study included 11561 students aged 9–18. Sleep was characterized by sleep timing (e.g., bedtime), sleep duration and sleep consistency (e.g., bedtime/wake-up time deviations and social jet lag (SJL)). We used odds ratios (OR) and 95% confidence intervals (95% CI) to assess the relationship between sleep and HBP. ResultsPrimary school students who slept 8.00–9.00h had a lower risk of HBP compared with sleeping >10h (OR 0.370, 95%CI 0.208, 0.658), while junior middle school students reporting ≤8.00h on weekday night had a lower risk of HBP compared with sleeping >10h (OR 0.303, 95%CI 0.111, 0.829). Moreover, compared with deviations = 0h, the OR (95%CI) for wake-up time deviations <0h and bedtime deviations >0h in primary school students with HBP were 0.314 (0.125, 0.790) and 2.155 (1.205, 3.853). Furthermore, compared with SJL = 0h, senior high school students reporting SJL = 0.01–0.50h, SJL = 0.51–1.00h and SJL = 1.01–2.00h had greater risk of HBP (OR 1.566, 95%CI 1.039, 2.361; OR 1.760, 95%CI 1.177, 2.631; OR 1.660, 95%CI 1.124, 2.452, respectively). Bedtime at night was associated with HBP for three educational periods students, however, there was no significant association between mid-day nap and HBP. ConclusionsSleep timing, sleep duration and sleep consistency are associated with high blood pressure in children and adolescents.

Prevalence of Insomnia among Medical Students

Objective: To determine the frequency and prevalence of insomnia among medical students of sheikh Zayed hospital and medical college Study design: Cross sectional study. Place and Duration of Study: Study started from 1st September 2018 and lasted to 30th March 2019 and was carried out at Sheikh Zayed Medical College and Hospital (Rahim Yar Khan). Methodology: This study was done through a questionnaire (Athens Insomnia Scale (AIS). Sample of the study consisted in medical students who were chose by random sampling to check the prevalence of insomnia. 75 students were male and 60 were female. Similarly,14 students from third year, 93 from fourth year and 28 from final year of MBBS. Complete history record maintain in academic years, sleep hour, midday nap and common cause of sleep disturbance mention in the literature: age, gender, habitat, BMI, physical activity, smoking and socioeconomic status was taken from the participant. During the interview, psychological assessment done for psychiatric illness and other screening for medical issues. Results: Study was done on the sample size (N) of two hundred and sixty (260) medical students. Response rate was 90% for two hundred and fifty students (250). 101(40.4%) were male out of these 250 students, and 149(59.6) were female students. Maximum and minimum age of the students was 25 years and 18 years respectively and mean age of the respondents was 21.076±1. This scale Athens Insomnia Scale, 102 (40.8%) participants were found to be insomnic and 148(59.2%) are non-insomniac. Among 102 Insomniac students, 70 were females and 32 were males. So result indicates that insomnia is more common in females then males. Conclusion: Insomnia is very common in medical student’s .This study shows that prevalence of insomnia in medical students is high. While the severity of insomnia is greater in female medical students as compare to the male students. Practical Implication: In our system, proper assessment of such problems would help in developing policies and adjusting medical study curricula to boost the output of one of the most expensive professional degree courses. Keywords: Insomnia, Medical students, Athens Insomnia Scale, BMI,

Effect of homeostatic pressure on daytime vigilance performance: Evidence from behaviour and resting-state EEG.

Vigilance is highly sensitive to the time-of-day effect and goes through the daytime trough during the period of the post-noon dip. A midday nap could maintain individuals' vigilance at an optimal level. Thus, homeostatic sleep pressure is one of the main reasons for the post-noon dip in daytime vigilance. The current study focussed on the role of homeostatic sleep pressure in the diurnal variation of vigilance performance with normal circadian rhythms and the corresponding neural basis. With 34 healthy adults, we recorded the resting-state electroencephalogram activities and the following vigilance performance measured by psychomotor vigilance test in the morning, the no-nap mid afternoon, and the nap mid afternoon. The circadian process was controlled by measuring vigilance and resting-state electroencephalogram activities at the same time point in the nap and no-nap conditions. Homeostatic sleep pressure accumulated from morning to mid afternoon induced the declined vigilance performance and a global increase in resting-state delta, theta, alpha, and beta1 bands power, and a local increase in beta2 band power in the central region. Furthermore, the more the spontaneous beta2 power increased, the less vigilance declined from morning to mid afternoon. The current findings suggest that homeostatic sleep pressure increased cortical excitability but decreased cortical communication efficiency from morning to mid afternoon. In addition, the activity of the high beta waves probably reflected the compensatory effort to counteract the negative impact of the low arousal state on the following vigilance task by performing more action preparation in the no-nap afternoon.

Hypnotizability May Relate to Interoceptive Ability to Accurately Perceive Sleep Depth: An Exploratory Study

ABSTRACT When individuals score high on hypnotizability, they usually report experiencing an altered state of consciousness, physiological changes, and attentional shifts during hypnotic induction procedures as well. We hypothesize that a better interoception of such internal changes is also relevant for accurate sleep perception. We compared subjects scoring high versus low on hypnotizability to the accuracy of their estimations of Sleep Onset Latency (SOL) time awake, and sleep depth and explored their objective sleep. We sampled seven studies performed in our sleep labs across a midday nap or a night resulting in n = 231 subjects (aged 30.11 (SD = 17.02) years, range 18–82 with 15.2% males). Hypnotizability did not influence the accuracy of the perception of time needed to fall asleep or time spent awake. However, the reported sleep depth correlated significantly with the measured amount of slow-wave sleep in high hypnotizables. This pattern appeared across a nap as well as a whole night’s sleep studies. We did not find any significant differences in objective sleep patterns depending on hypnotizability. Probably, high hypnotizables benefit from a better interoceptive ability for their perception of their sleep depth.

Effects of an afternoon nap on sustained attention and working memory: The role of physiological arousal and sleep variables

Taking a short midday nap has been associated with higher alertness and better cognitive task performance. Yet, the mechanisms associated with nap-dependent performance enhancement are unclear. The current study was conducted to explore the impact of physiological arousal during cognitive task and sleep architecture during a pre-task nap on post-nap behavioral outcomes. A within-subjects design (N = 18) was employed, in which participants either took a nap or remained awake for 40 min during the post-lunch period. The psychomotor vigilance test (PVT) and n-back task were administered to assess sustained attention and working memory, respectively, with each task including one block of easy trials and one block of difficult trials. Results showed that a short midday nap improved sustained attention but not working memory. In addition, a midday nap induced lower physiological arousal during the performance on both cognitive tasks, with relatively higher delta and lower beta activity. The relative power of theta and alpha were positively correlated with performance on the easy PVT, whereas the alpha power was negatively correlated with performance on the difficult PVT, and the theta power was negatively correlated with reaction speed in the n-back task regardless of the task difficulty. Meanwhile, the shorter total sleep time and longer time of wake after sleep onset were associated with the faster overall reaction speed in PVT easy trials. These findings suggested that both changes in physiological arousal and sleep variables might account for changes in task performance after a short midday nap.

Hypoxia Differentially Affects Healthy Men and Women During a Daytime Nap With a Dose-Response Relationship: a Randomized, Cross-Over Pilot Study.

Context: The use of daytime napping as a countermeasure in sleep disturbances has been recommended but its physiological evaluation at high altitude is limited. Objective: To evaluate the neuroendocrine response to hypoxic stress during a daytime nap and its cognitive impact. Design, Subject, and Setting: Randomized, single-blind, three period cross-over pilot study conducted with 15 healthy lowlander subjects (8 women) with a mean (SD) age of 29(6) years (Clinicaltrials identifier: NCT04146857, https://clinicaltrials.gov/ct2/show/NCT04146857?cond=napping&draw=3&rank=12). Interventions: Volunteers underwent a polysomnography, hematological and cognitive evaluation around a 90 min midday nap, being allocated to a randomized sequence of three conditions: normobaric normoxia (NN), normobaric hypoxia at FiO2 14.7% (NH15) and 12.5% (NH13), with a washout period of 1 week between conditions. Results: Primary outcome was the interbeat period measured by the RR interval with electrocardiogram. Compared to normobaric normoxia, RR during napping was shortened by 57 and 206 ms under NH15 and NH13 conditions, respectively (p < 0.001). Sympathetic predominance was evident by heart rate variability analysis and increased epinephrine levels. Concomitantly, there were significant changes in endocrine parameters such as erythropoietin (∼6 UI/L) and cortisol (∼100 nmol/L) (NH13 vs. NN, p < 0.001). Cognitive evaluation revealed changes in the color-word Stroop test. Additionally, although sleep efficiency was preserved, polysomnography showed lesser deep sleep and REM sleep, and periodic breathing, predominantly in men. Conclusion: Although napping in simulated altitude does not appear to significantly affect cognitive performance, sex-dependent changes in cardiac autonomic modulation and respiratory pattern should be considered before napping is prescribed as a countermeasure.

Midday naps Effects in type 2 diabetics with reduced night-time sleep

Midday naps Effects in type 2 diabetics with reduced night-time sleep

P 87 Slow wave sleep of a 90-minute nap relates to hippocampus-dependent spatial memory consolidation

Introduction : The hippocampus is critical for learning and consolidation of behaviourally-relevant spatial information. During spatial learning, spatially-related firing patterns of hippocampal place cells reflecting the subjects‘ location can be detected. It is widely acknowledged that the stabilization of newly encoded memory traces during active system consolidation is promoted by post-learning slow wave sleep (SWS). Here, hippocampal neural sequences are reactivated (“replay”) accompanied by neocortical slow oscillations thereby synchronizing spindle-ripple events originating from hippocampal and thalamic regions. Studies in rodents and humans reported a facilitation of spatial memories after full nights of sleep, in particular in early sleep SWS (i.e., sharp-wave ripples and slow waves). In this ongoing study, we investigated the effect of a 90-min nap on sleep-associated memory consolidation of spatial information. The advantage of an isolated nap condition is the possibility to selectively study the effect of SWS on memory consolidation. Patients & Methods: Forty healthy students between 21 and 32 years were divided into a sleep group (24±1,64 years, 55% female) and a wake group (24±2,68 years, 55% female). For testing spatial learning, the Virtual Water Maze (VWM), a digitalised version of the established Morris Water Maze Test for hippocampus-dependent place learning was used. Here, students had to find a treasure box hidden in the same position on a virtual island. Between learning and the recall sessions of the VWM (90 minutes), students either performed a mid-day nap accompanied by polysomnography (sleep condition) or watched emotionally neutral documentaries (wake condition). The improvement in the recall session was then compared between the groups and the influence of EEG sleep measures was analysed. Results: We found a significant positive correlation between spatial memory consolidation and time spent in SWS (SWS [min]: r=0,612, p=0,004). Accordingly, there was a tendency of a stronger consolidation when amounts of slow oscillations and sleep spindles were higher. When directly compared, there was no significant difference in the various consolidation measures of VWM between the groups . Conclusion: We found that consolidation of hippocampus-dependent spatial memory in a young healthy population was related to longer time spent in SWS as well as the amount of sleep spindles and slow oscillations during NonREM sleep of a 90-minute nap. Our data support the notion that the efficacy of hippocampus-dependent spatial memory consolidation depends on the duration of SWS.

Associations Between Total Sleep Duration and Cognitive Function Among Middle-Aged and Older Chinese Adults: Does Midday Napping Have an Effect on It?

AimThe effect of sleep duration on cognitive function has been reported. However, the studies about the combined effects of total sleep duration and midday napping on cognition in elders were limited and inconclusive. We aimed to investigate the associations between total sleep duration, midday napping and cognitive function among middle-aged and older Chinese adults.MethodsBased on the 3rd wave of the China Health and Retirement Longitudinal Study (CHARLS) in 2015, a total of 9218 participants aged ≥45 years with completed cognition measurements were included. Cognitive functions were assessed by a combined global cognition score of episodic memory and mental status. Information about sleep-related variables, demographic characteristics, and health status were collected by validated questionnaires. Multivariate linear regression models were performed to evaluate the associations between total sleep duration, midday napping, and cognitive function. Stratified analyses were used to explore the potential effect modifier.ResultsOverall, the global cognition score was 10.38 ± 4.30 among the participants (mean age: 61.5 ± 8.7 years). For sleep duration, both short sleep and long sleep duration were significantly associated with the increased risk of cognitive impairment after controlling for demographics and other confounders. Compared with sleeping for 7h per day, the adjusted β-coefficient and 95% CI of the risk of cognitive impairment was −0.967 (95% CIs: −1.191, −0.742) for ≤5h, −0.257 (−0.498, −0.016) for 6h, −0.424 (−0.650, −0.198) for 8h and −0.664 (−0.876, −0.452) for ≥9h. The combined effect analysis indicated that subjects with extended or without naps had a significantly higher risk of cognitive impairment in the ≤5h sleep time group (ref: 7h) and in extended nappers or without naps group (ref: short nappers). Subjects with extended naps or without naps might increase the risk of cognitive impairment, especially those having ≤5h total sleep time. Stratified analysis showed that participants aged ≥60 years without social activity increased the risk of cognitive decline.ConclusionAn inverted U-shaped association was observed between total sleep duration and cognitive function in Chinese elders, especially in those aged ≥60 years or without social activity. Short midday naps could mitigate the deleterious effects of poor sleep quality and shorter sleep duration on cognitive function. The findings could help us identify the vulnerable population and decrease the burden of cognitive impairment.

Aging-Related Changes in Cortical Sources of Sleep Oscillatory Neural Activity Following Motor Learning Reflect Contributions of Cortical Thickness and Pre-sleep Functional Activity.

Oscillatory neural activity during sleep, such as that in the delta and sigma bands, is important for motor learning consolidation. This activity is reduced with typical aging, and this reduction may contribute to aging-related declines in motor learning consolidation. Evidence suggests that brain regions involved in motor learning contribute to oscillatory neural activity during subsequent sleep. However, aging-related differences in regional contributions to sleep oscillatory activity following motor learning are unclear. To characterize these differences, we estimated the cortical sources of consolidation-related oscillatory activity using individual anatomical information in young and older adults during non-rapid eye movement sleep after motor learning and analyzed them in light of cortical thickness and pre-sleep functional brain activation. High-density electroencephalogram was recorded from young and older adults during a midday nap, following completion of a functional magnetic resonance imaged serial reaction time task as part of a larger experimental protocol. Sleep delta activity was reduced with age in a left-weighted motor cortical network, including premotor cortex, primary motor cortex, supplementary motor area, and pre-supplementary motor area, as well as non-motor regions in parietal, temporal, occipital, and cingulate cortices. Sleep theta activity was reduced with age in a similar left-weighted motor network, and in non-motor prefrontal and middle cingulate regions. Sleep sigma activity was reduced with age in left primary motor cortex, in a non-motor right-weighted prefrontal-temporal network, and in cingulate regions. Cortical thinning mediated aging-related sigma reductions in lateral orbitofrontal cortex and frontal pole, and partially mediated delta reductions in parahippocampal, fusiform, and lingual gyri. Putamen, caudate, and inferior parietal cortex activation prior to sleep predicted frontal and motor cortical contributions to sleep delta and theta activity in an age-moderated fashion, reflecting negative relationships in young adults and positive or absent relationships in older adults. Overall, these results support the local sleep hypothesis that brain regions active during learning contribute to consolidation-related neural activity during subsequent sleep and demonstrate that sleep oscillatory activity in these regions is reduced with aging.

Sleep as Homework and Engagement in Rehabilitation

In today’s push for shorter and quicker hospitalisations, everyday life often becomes a place of rehabilitation for people after they undergo surgical procedures. In order for hospitals to manage shortened periods of admission and to facilitate post-operative rehabilitation, a patient‘s active engagement has become a central element to clinical treatment and care in Denmark. For example, in the recovery from orthopedic surgery, sleep becomes a type of "homework" assignment that is a vital element of the patient‘s rehabilitation trajectory. Building on the theoretical concept of ‘engagement’ developed by Gilles Deleuze and Félix Guattari (2005), we examine the patient‘s relation to sleep as part of recovery; we refer to this as ‘sleep engagement.’ In particular, we analyze sleep as part of an institutional pedagogy in rehabilitation, and we ask how this pedagogy mobilizes rehabilitation for older patients after they have been admitted to the hospital for an orthopedic surgical procedure. Using ethnographic material, our analysis leads to a discussion of institutional expectations for what it means to be engaged in one's own patient trajectory. The article presents three results: 1) Expectations of sleep as an institutionally defined homework assignment are fulfilled through the establishment of the ‘rehabilitable and non rehabilitable body’; 2) As an active attempt to mobilize resources in rehabilitation, patient sleep engagement becomes part of a historical and contextual nexus; and 3) Institutional sleep potential creates new points of ambivalence—on the one hand, sleep is an optimization-promoting requirement in order to exercise while, on the other hand, the midday nap reflects an outdated view of old age that opposes an active lifestyle perspective.

Prevalence of metabolic syndrome, its risk factors and associated lifestyles in Myanmar adult people: A community based cross-sectional study

ObjectivesMetabolic syndrome (MetS) is the constellation of cardio-metabolic risk factors, and it can illustrate the coming burden of cardiovascular diseases and diabetes mellitus. Myanmar faces larger pressure from cardio-metabolic diseases and there is no existing data to understand the magnitude of MetS in adult population. This study aimed to investigate the extent of existing people with MetS in the community and to know the related lifestyle factors to MetS. MethodsA community based cross-sectional study was performed in convenient sample of 302 Myanmar adult people. Prevalence of MetS and associated risk factors were identified by collecting sociodemographic information, anthropometric measurements, and blood investigation of glucose and lipid profiles. Logistic regression analysis was performed for developing statistical models to estimate the odd ratios (OR) and confidence intervals (CI). ResultsPrevalence of MetS is 29.1%, and there is no significant difference between male and female prevalence. Abdominal obesity is the highest component of MetS (OR: 28.37, CI: 12.41–64.85, p < 0.001) especially for female (OR: 44.52, CI: 17.19–115.31, p < 0.001), and hypertriglyceridemia (OR: 11.05, CI: 6.20–19.66, p < 0.001) is the commonest in male. Age is the constant risk for developing MetS (OR: 4.06, CI: 1.91–8.64, p < 0.001) whereas the practice of midday nap is the behavior related to increased occurrence of MetS (OR: 1.97, CI: 1.16–3.38, p < 0.05). Dietary pattern, smoking status, drinking alcoholic beverages and physical activity involvement do not impact on the development of MetS. Education, occupation, income and other sociodemographic factors do not produce significant effect on cardio-metabolic status. Obesity, diabetes, and hypertensive conditions of community residents are also explored. ConclusionsModifiable pathophysiological conditions such as abdominal obesity, and obesity play a vital role in preventing MetS before it occurs while unmodifiable risk factor such as getting older and female sex are not as much important as changeable lifestyle habits.

Ageing-related changes in nap neuroscillatory activity are mediated and moderated by grey matter volume.

Ageing‐related changes in grey matter result in changes in the intensity and topography of sleep neural activity. However, it is unclear whether these findings can be explained by ageing‐related differences in sleep pressure or circadian influence. The current study used high‐density electroencephalography to assess how grey matter volume differences between young and older adults mediate and moderate neuroscillatory activity differences during a midday nap following a motor sequencing task. Delta, theta, and sigma amplitude were reduced in older relative to young adults, especially over frontocentral scalp, leading to increases in relative delta frontality and relative sigma lateral centroposteriority. Delta reductions in older adults were mediated by grey matter loss in frontal medial cortex, primary motor cortex, thalamus, caudate, putamen, and pallidum, and were moderated by putamen grey matter volume. Theta reductions were mediated by grey matter loss in primary motor cortex, thalamus, and caudate, and were moderated by putamen and pallidum grey matter volume. Sigma changes were moderated by putamen and pallidum grey matter volume. Moderation results suggested that across frequencies, young adults with more grey matter had increased activity, whereas older adults with more grey matter had unchanged or decreased activity. These results provide a critical extension of previous findings from overnight sleep in a midday nap, indicating that they are not driven by sleep pressure or circadian confounds. Moreover, these results suggest brain regions associated with motor sequence learning contribute to sleep neural activity following a motor sequencing task.

The impact of daytime napping on athletic performance - A narrative review.

Mid-day napping has been recommended as a countermeasure against sleep debt and an effective method for recovery, regardless of nocturnal sleep duration. Herein, we summarize the available evidence regarding the influence of napping on exercise and cognitive performance as well as the effects of napping on athletes' perceptual responses prior to or during exercise. The existing studies investigating the influence of napping on athletic performance have revealed equivocal results. Prevailing findings indicate that following a normal sleep night or after a night of sleep loss, a mid-day nap may enhance or restore several exercise and cognitive performance aspects, while concomitantly provide benefits on athletes' perceptual responses. Most, but not all, findings suggest that compared to short-term naps (20-30min), long-term ones (>35-90min) appear to provide superior benefits to the athletes. The underlying mechanisms behind athletic performance enhancement following a night of normal sleep or the restoration after a night of sleep loss are not clear yet. However, the absence of benefits or even the deterioration of performance following napping in some studies is likely the result of sleep inertia. The present review sheds light on the predisposing factors that influence the post-nap outcome, such as nocturnal sleep time, mid-day nap duration and the time elapsed between the end of napping and the subsequent testing, discusses practical solutions and stimulates further research on this area.

Does Bright Light Counteract the Post-lunch Dip in Subjective States and Cognitive Performance Among Undergraduate Students?

The post-lunch dip in alertness and performance was widely experienced during the early afternoon. Taking a short nap was documented as a practical strategy for habitual nappers to counteract the decline of alertness and performance. Yet, it remains unknown whether bright light exposure in the early afternoon working hours could alleviate the performance deficits caused by a post-lunch nap loss for habitual nappers. Seventeen undergraduate students who had a long-term habit of taking a post-lunch nap were assigned to three interventions: (1) a short nap + normal indoor light (100 lx, 4,000 K at eye level); (2) no nap + normal indoor light, and (3) no nap + blue-enriched bright light (1,000 lx, 6,500 K at eye level), in which subjective alertness (Karolinska Sleepiness Scale, KSS), mood (Positive and Negative Affect Schedule, PANAS), and task performance in sustained attention (psychomotor vigilance test, PVT), response inhibition (go/no-go task), and working memory (paced visual serial addition test, PVSAT) were measured. Results showed that a post-lunch nap deprivation significantly increased subjective sleepiness and negative mood and impaired performance in PVT and PVSAT, while exposure to bright blue-enriched white light vs. normal indoor light in the early afternoon significantly relieved such negative effects on mood, sleepiness, and performance in PVSAT; subjective positive mood and performance in PVT and go/no-go task remained unaffected with light intervention. These findings suggested that bright blue-enriched white light exposure could be a potential strategy for those who are suffering from drowsiness and low working memory following a habitual midday nap loss.