Wake Time Research Articles

Combined use of dexmedetomidine and nalbuphine in laparoscopic radical gastrectomy for gastric cancer.

Radical laparoscopic gastrectomy is an important treatment modality for gastric cancer. Surgery requires general anesthesia, and patients are susceptible to the effects of anesthetic drugs and carbon dioxide insufflation during the procedure, leading to inflammation or severe pain, which can affect patient outcome. To explore the efficacy of combining dexmedetomidine (DEX) with nalbuphine in patients underwent laparoscopic radical gastrectomy for gastric cancer. Patients scheduled to undergo laparoscopic radical gastrectomy were selected and randomly assigned to A or B group. In A group, patients received an intravenous injection of nalbuphine 0.2 mg/kg + DEX 0.4 μg/kg 10 min before the end of surgery; in B group, patients received only an intravenous injection of nalbuphine. The trends in hemodynamic parameter fluctuations, awakening quality during the recovery period, serum inflammatory markers, agitation scores, cough severity, incidence, and duration of postoperative delirium (POD) were compared. The mean arterial pressure and heart rate in the A group were more stable (P < 0.05). The A group had a lower average awakening time, extubation time, and agitation scores during recovery than the B group. Agitation control in the A group was more effective at different time points (P < 0.05). Patients in the A group had lower serum interleukin (IL)-6, tumour necrosis factor alpha, and IL-10 levels at 1 h after surgery than the B group. The incidence of coughing and duration of POD were lower and shorter in the A group than in the B group. Adverse reactions caused by the two anesthesia methods were less frequent in the A group than in the B group (P < 0.05). The use of DEX and nalbuphine in patients undergoing laparoscopic radical gastrectomy for gastric cancer help reducing the inflammatory response, cough severity, and agitation and helps maintain hemodynamic stability.

Effects of an OX2R agonist on migration and removal of tau from mouse brain

Pathological proteins including tau are produced in neurons and released into interstitial fluid (ISF) in a neural activity-dependent manner during wakefulness. Pathological proteins in ISF can be removed from the brain via the glymphatic pathway during nighttime. Thus, in individuals with Alzheimer’s disease (AD) that have dysregulated sleep/wake rhythm, application of orexin receptor 2 (OX2R) agonists during daytime could recover the efflux of pathological proteins to ISF and indirectly promote the glymphatic pathway by improving the quality of nighttime sleep after proper daytime arousal, resulting in increased removal of these proteins from the brain. We investigated this hypothesis using OX-201, a novel OX2R-selective agonist with a 50% effective concentration of 8.0 nM. Diurnal rhythm of tau release into hippocampal ISF correlated well with neuronal activity and wakefulness in wild-type mice. In both wild-type and human P301S tau transgenic mice, OX-201 induced wakefulness and promoted tau release into hippocampal ISF. Human P301S tau transgenic mice, tested under our conditions, showed longer wakefulness time, which differs from individuals with AD. OX-201 treatment over 2 months did not alter hippocampal tau levels. Although further studies are required, at a minimum OX2R agonists may not exacerbate tau accumulation in individuals with tauopathy, including AD.

Sociodemographic determinants of sedentary behavior and physical activity assessed by triaxial accelerometry in Brazilian adults diagnosed with type 2 Diabetes

Sedentary behavior (SB) and physical activity (PA) are distinct physical behaviors influencing health outcomes, particularly in individuals with type 2 diabetes (T2D). Increased SB is associated with higher cardiometabolic risk, while PA, especially moderate-to-vigorous intensity physical activity (MVPA), is linked to reduced mortality and improved health. Given the diverse sociodemographic context of Brazil, understanding the determinants of SB and PA in Brazilian adults with T2D is essential. To investigate the association of sociodemographic and clinical factors with SB, light-intensity physical activity (LIPA), and MVPA among Brazilian adults diagnosed with T2D, and to assess adherence to MVPA guidelines. This cross-sectional study involved 150 adults. Daily SB and PA were measured using ActiGraph™ triaxial accelerometers over eight days. Sociodemographic and clinical data were collected via questionnaires. Data were analyzed using descriptive statistics, t-tests, chi-square tests, and multivariate linear regression models. Participants spent 48.5% of daily awake time in SB, 47% in LIPA, and &lt;5% in MVPA. Gender significantly influenced SB and LIPA; males spent more time in SB and less in LIPA than females. Employment status also affected LIPA, with unemployed individuals engaging less in LIPA. Sixty-one percent of participants met MVPA guidelines, yet a high sedentary tendency persisted. Sociodemographic factors, particularly gender and employment status, significantly influence SB and LIPA in Brazilian adults living with T2D. Despite adherence to MVPA guidelines, the predominantly SB underscores the need for public health strategies promoting all PA intensities, especially LIPA, to mitigate SB's adverse effects.

Sex-specific associations between self-reported sleep characteristics and 10-year cardiovascular disease risk in men and women of African descent living in a low socioeconomic status environment

BackgroundRisk factors for cardiovascular disease (CVD) and sleep health are well-known to be sex- and race-specific. To build on the established relationship between sleep duration and CVD risk, this cross-sectional study aimed to describe sex-specific associations between CVD risk and other sleep characteristics (sleep quality, sleep timing and sleep onset latency) in low-income adults of African descent. MethodsSelf-reported sleep (Pittsburgh Sleep Quality Index [PSQI], Epworth Sleepiness Scale [ESS], Insomnia Severity Index [ISI]), demographic and lifestyle data were collected in 412 adults (56 % women, 35.0 ± 7.6y, 40 % employed) living in an informal settlement in South Africa. CVD risk was determined using the BMI-modified Framingham 10-year CVD risk formula. ResultsLogistic regression analyses, adjusted for employment, alcohol use and physical activity, indicated that men reporting poor sleep quality (OR: 1.95[95 %CI: 1.07–3.51], p=0.025) and earlier bedtimes (0.54[0.39–0.74], p<0.001) were more likely to belong to a higher 10-year CVD risk score quintile. Women reporting earlier bedtimes (0.72[0.55–0.95], p=0.020) and wake-up times (0.30[0.13–0.73], p=0.007), longer sleep-onset latency (1.47[1.43–1.88], p=0.003), shorter total sleep times (0.84[0.72–0.98], p=0.029), higher PSQI global scores (1.93[1.29–2.90], p=0.001) and more moderate to severe symptoms of insomnia (ISI≥15)(3.24[1.04–10.04], p=0.016) were more likely to belong to higher 10-year CVD risk score quintile. ConclusionIn addition to sleep duration, we found that sleep quality, sleep timing and sleep onset latency are additional risk factors for CVD in adults of African descent. Sex-specific differences in the sleep-CVD-risk relationship observed suggests that future studies and recommendations about sleep health in relation to CVD should take sex into account.

Effect of Training Load Intensification on the Sleep Pattern of Young Soccer Players

ABSTRACT Purpose: The aim of this study was to examine how intensifying training loads over a week affects the sleep patterns of young soccer players on the nights immediately following the intensified training sessions. Methods: Quasi-experimental study. Fifteen young athletes participants of a team engaged in national level competition, underwent two weeks of training with varying load magnitudes—Week 1: low accumulated training load and Week 2: intensified training loads [40% increase in external training load(ETL)]. To characterize the intensification of the workload, the methods PlayerLoad and RPE-Session were employed to measure ETL and internal training load(ITL), respectively. Total sleep time(TST), total time in bed(TTB), sleep efficiency(SE), sleep latency(SL), and wake after sleep onset(WASO) were obtained using actigraphy and daily sleep log. The variables were compared among the days of week (e.g. Monday of week 1 with Monday of week 2, and so forth). Results: Acute training intensification in week 2 led to significant increases in ETL and ITL on Monday and on Wednesday(p < .05), and ETL(p < .05) on Friday on the second week. Improvements in sleep were observed (Tuesday—TST:+80 min, WASO:-29.3 min, SL:-8 min, SE:+9%; Thursday—TST:+86 min, SL:-4 min, SE:+4%; Saturday—TST:+40 min, SL:+1 min) compared to the same day of the previous week. Correlations between ETL and ITL(r = 0.637), ITL and TST(r = 0.572), ITL and SE(r = 0.548) were found. Conclusion: Intensification of training loads results in alterations in sleep variables, notably an elevated TST and SE in the days subsequent to the acute load increment.

An exploration into the sleep of workers on block-calving, pasture-based dairy farms

The benefits of sufficient and high-quality sleep for people are well documented. Insufficient sleep increases the risk of accidents, injuries, and negative health implications for people. This is especially relevant for farmers because they work with large animals and machinery. Dairy farming often requires early start times and long days, particularly over the high-workload calving period in block-calving, pasture-based systems. However, there is little published data quantifying the sleep quantity and quality of farmers over this period. In this study, the sleep patterns of workers (n = 33) on 10 New Zealand dairy farms were measured for 90 d over the spring calving period using a sleep measuring device (Oura ring, Oura Health Ltd., Oulu, Finland). Total sleep time (TST) averaged 6 h 15 min, lower than the required 7 to 9 h for optimal wellbeing and cognitive functioning. The TST decreased over the calving period and was significantly correlated with both sleep start and wake times. Factors such as work start time, farm location, and role on farm influenced sleep quantity and quality. Further research is required to better understand sleep and its effect on dairy farmers, over both the calving period and the remaining months of the year.

Association Between Gastrointestinal and Sleep Problems in the General Population of Japan: A Cross-Sectional Community-Based Observational Study.

Background and aim Poor sleep is known to be associated with functional gastrointestinal (GI) problems in the general population, but the exact mechanisms underlying the relationship remainunclear. Deeper insights into the exact mechanisms underlying the connection may benefit individuals suffering from these conditions without efficient treatments. Therefore, this study investigated the association between functional GI symptom levels and sleep-related characteristics in the general population of Japan. Methods In this cross-sectional questionnaire-based observational study, data including the self-reported levelof poor sleep and functional GI symptoms in the last one month were collected fromconsecutive individuals who visited a hospital in Miyagi Prefecture, Japan, for regular medical checkups between April 2020 and March 2023. The levels of other physical and mental conditions, such as stress at home, fatigability, irritability, thermoregulatory problems, and edema in the limbs, were measured with an 11-point Numerical Rating Scale (NRS) between 0 and 10. Additional sleep-related specific information, such as sleep length, wake-up time, bedtime, trouble falling asleep, and nocturnal awakening, were further collected. Correlations with functional GI symptoms in these characteristics were evaluated by bivariate correlation analyses and generalized regression analyses. Results A total of 151 consecutive adults aged ≥18 years (77 males and 74 females) participated in this study. In bivariate correlation analyses, chronic GI symptom levels were significantly correlated with stress at home (p=0.0005), fatigability (p=0.0008), irritability (p=0.0022), edema in the limbs (p<0.0001), and sleep problem (p<0.0001). In the following generalized regression analysis, significant correlations with GI symptom levels were observed in sleep problems (p=0.0042) and edema in the limbs (p=0.0256). Further bivariate correlation analyses using sleep-related subscales revealed that trouble falling asleep in bed (p=0.0001), midnight awakening (p=0.0143), and wakeup time (p=0.0465) were correlated with GI symptom levels. In the following generalized regression analysis, a significant correlation withGI symptom levels was observed in trouble falling asleep (p=0.0239). Conclusion Functional GI symptoms in the general population of Japan were associated with poor sleep, even after adjusting for daily stress and irritability levels. Among the sleep-related characteristics, trouble falling asleep was associated with GI dysfunctions. Assessing sleep-related information and achieving good sleep quality with smooth sleep induction may be a clue to relieving GI dysfunctions with uncertain causes.

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.

Effect of Music Therapy on Negative Psychology, Sleep, and Quality of Life in Elderly Patients Recovering from Cerebral Infarction with Depression and Anxiety: A Retrospective Analysis.

To observe the effects of music therapy on negative psychology, sleep, and quality of life in elderly patients recovering from cerebral infarction accompanied by depression and anxiety. We performed a retrospective analysis of 160 patients with convalescent cerebral infarction diagnosed between December 2022 and December 2023 in the Affiliated Brain Hospital of Nanjing Medical University. Cases from the control group (n = 76) were treated with conventional rehabilitation training. Meanwhile, the music therapy group (n = 84) cases were managed with standard and music therapy. Various measures, including polysomnography, the general quality of life questionnaire-74 (GQOL-74), the self-rating anxiety scale (SAS), and the self-rating depression scale (SDS) were collected at baseline (admission) and 4 weeks post-admission. After 4 weeks, the music therapy group exhibited higher GQOL-74 scores, lower SAS scores, and lower SDS scores (P < 0.001). Furthermore, compared with the control group, the music therapy group had shorter sleep latency, longer sleep duration, higher sleep efficiency, lower wake time, fewer wake times, shorter S1 stage, longer S3 + S4 stage, and longer REM period (P < 0.001). Music therapy appears to be effective in improving negative psychology, sleep quality, and quality of life in elderly patients with comorbid depression and anxiety during recovery from cerebral infarction.

Hot flashes and sleep disruption in a randomized trial in menopausal women

BackgroundHot flashes, common during menopause, affect up to 80% of Western menopausal women and are reported to contribute to sleep disturbances in midlife. Few prospective data are available to confirm the specific role of hot flashes in disrupting sleep in midlife women, however, or confirm whether changes in hot flashes in response to clinical therapies result in improvement in sleep. ObjectiveTo examine the effects of continuous nitroglycerin therapy on sleep quality in peri- and postmenopausal women with frequent hot flashes (pre-specified secondary trial endpoint), and to examine prospective associations between hot flashes and sleep disruption in this population. Study DesignSleep data were analyzed from a randomized, double-blinded, placebo-controlled trial of continuous transdermal nitroglycerin (NTG) therapy to suppress nitric oxide-mediated vasodilation in peri- or postmenopausal women with hot flashes. Participants were randomized to uninterrupted use of transdermal NTG (0.2-0.6 mg/hour) or placebo for 12 weeks. Nocturnal hot flashes awakening participants from sleep were evaluated using 7-day symptom diaries at baseline, 5 weeks, and 12 weeks. Sleep disruption (wake time after sleep onset, WASO) was assessed using validated sleep diaries, and global sleep quality was assessed by the validated Pittsburgh Sleep Quality Index (PSQI: range 0 [best] 21 [worst]) questionnaire. Mixed linear models examined changes in sleep quality and disruption, as well as the strength of associations between nocturnal hot flash frequency and sleep outcomes, over 5 and 12 weeks, adjusting for baseline values, age, race, and ethnicity. ResultsAmong the 141 participants (70 to NTG and 71 to placebo, mean age 54.6 [±3.9] years), the mean baseline hot flash frequency was 10.8 (±3.5) per day, including 2.6 (±1.7) nocturnal hot flashes awakening participants. At baseline, hot flashes were the most commonly reported reason for nocturnal awakening, with 62.6% of participants reporting waking due to hot flashes at least twice nightly. Over 5 and 12 weeks, mean frequency of nocturnal hot flashes causing awakenings decreased in both groups (NTG: -0.9 episodes/night, placebo: -1.0 episodes/night). Sleep disruption as measured by average nightly WASO also decreased (NTG: -10.1 minutes, placebo: -7.3 minutes), and mean PSQI score improved (NTG: -1.3 points, placebo: -1.2 points). No significant between-group differences in change in sleep outcomes were detected from baseline to 5 and 12 weeks, including PSQI sleep quality score as a pre-specified secondary trial endpoint (P ≥ .05 for all). Greater improvement in nocturnal hot flash frequency over 5 and 12 weeks was associated with greater improvement in PSQI sleep quality score (β= -0.30, P=.01) and sleep disruption reflected by WASO (β= -1.88, P=.02) in the combined sample. ConclusionAmong menopausal women in a randomized trial of continuous NTG therapy for hot flashes, hot flashes were the most frequently reported cause of nocturnal awakenings. Compared to placebo, continuous NTG therapy did not result in greater improvements in sleep quality from baseline to 5 and 12 weeks. Based on night-by-night symptom diaries and questionnaires, however, greater improvement in nocturnal hot flash frequency in both groups was associated with greater improvement in sleep quality and disruption.

Associations between Sleep and Physical Activity Behavior Clusters and Epigenetic Age Acceleration in Mexican Adolescents.

Epigenetic aging, a marker of biological aging measured by DNA methylation, may be affected by behaviors, including sleep and physical activity. However, investigations of physical activity and sleep with epigenetic aging among pediatric populations are scant and have not accounted for correlated behaviors. The study population included 472 Mexico City adolescents (52% female). Blood collection and 7-d wrist actigraphy (Actigraph GTX-BT) occurred during a follow-up visit when participants were 14.5 (2.09) yr. Leukocyte DNA methylation was measured with the Infinium MethylationEPIC array after bisulfite conversion, and nine epigenetic clocks were calculated. Sleep versus wake time was identified through a pruned dynamic programing algorithm, and physical activity was processed with Chandler cutoffs. Kmeans clustering was used to select actigraphy-assessed physical activity and sleep behavior clusters. Linear regression analyses were used to evaluate adjusted associations between the clusters and epigenetic aging. There were three unique clusters: "Short sleep/high sedentary behavior," "Adequate sleep duration and late sleep timing/low moderate or vigorous physical activity (MVPA)," and "Adequate sleep duration/high MVPA." Compared with the "Adequate duration/high MVPA," adolescents with "Adequate duration and late sleep timing/low MVPA" had more accelerated aging for the GrimAge clock ( β = 0.63; 95% confidence interval, 0.07-1.19). In pubertal-stratified analyses, more mature adolescents in the "Adequate sleep duration and late sleep timing/low MVPA group" had accelerated epigenetic aging. In contrast, females in the "Short sleep/high sedentary" group had decelerated epigenetic aging for the Wu pediatric clock. Associations between behavior clusters and epigenetic aging varied by pubertal status and sex. Contrary results in the Wu clock suggest the need for future research on pediatric-specific clocks.

Parental Knowledge and Practices of Sleep Hygiene Among Children in Saudi Arabia: A Cross-Sectional Study.

Sleep hygiene is crucial for child development, influencing physical health, cognitive function, and emotional well-being. Parental knowledge and practices significantly influence children's sleep habits, yet gaps in understanding persist, impacting sleep quality and overall health outcomes. In Saudi Arabia, rapid societal changes and modern lifestyles pose unique challenges to maintaining healthy sleep habits among children. This study aims to assess parental knowledge and management of sleep hygiene, providing insights for targeted interventions tailored to Saudi cultural contexts. This cross-sectional study assessed parental knowledge and management of sleep hygiene among children in Saudi Arabia. Participants (N=729) were recruited from pediatric clinics and online forums, comprising parents with at least one child aged 0-18 years who completed surveys in Arabic or English. A comprehensive survey collected demographic data, parental sleep hygiene knowledge, practices, and concerns. Data were gathered between January and March 2024 via online and clinic-based distribution and analyzed using SPSS version 25 for descriptive statistics. The survey was completed by 729 participants, predominantly aged 25-44 years (70.4%), holding predominantly bachelor's degrees (34.7%), and employed full-time (49.7%). The majority reported having 2-3 children (54.9%). Findings indicated that 69.1% (504 participants) correctly identified school-aged children's sleep needs, and 71.0% (518 participants) recognized the importance of limiting electronic device use before bedtime. Sleep management practices revealed that 81.3% (592 participants) of parents adhered to bedtime routines, and 65.6% (478 participants) managed electronic device use appropriately. Bedtimes typically ranged from 7 to 9 PM for 90.5% (658 participants) of children, with wake-up times clustered between 6 and 8 AM for 75.6% (551 participants). Parental concerns showed reliance on online resources (60.4%) and pediatricians (54.7%) for sleep information, with 73.9% (539 participants) expressing interest in further education on sleep hygiene. This study highlights parental awareness of sleep hygiene practices in Saudi Arabia but underscores gaps in knowledge regarding caffeine effects and optimal napping practices. Tailored educational interventions are essential to enhance parental understanding and promote healthier sleep habits, thereby optimizing child well-being in the region.

DPoSEB: Delegated Proof of Stake with Exponential Backoff Consensus Algorithm for Ethereum Blockchain

Blockchain is a technology that is rapidly gaining prominence and finding applications in various sectors such as banking, supply chain, healthcare, and e-governance. The consensus algorithm employed in a blockchain network is crucial as it directly impacts the network's performance and security. Different consensus techniques exist, including Proof of Work (PoW), Proof of Stake (PoS), Robust Proof of Stake (RPoS), and Delegate Proof of Stake (DPoS), each with its own set of advantages and disadvantages. In this work, we propose a new consensus algorithm called Delegated Proof of Stake with Exponential Back-off (DPoSEB). DPoSEB utilizes a stake-based selection of delegates and employs an exponential back-off technique to mitigate collisions among nodes within the network. Each delegate is assigned a random sleep time, and the node with the shortest wake-up time is chosen to mine the block for that particular round. However, collisions among nodes can still occur. To provide a fair chance for each delegate node, collided nodes are assigned an exponential back-off time. We implement our proposed algorithm on an Ethereum-based private blockchain network. To evaluate the effectiveness of our proposed work, we compare it with existing consensus mechanisms such as PoS (version 2) and Delegated RPOS with downgrading (DDRPOS) using different scenarios in terms of transaction latency, waiting time, and fairness as evaluation metrics. The results reveal that DPoSEB performs better than POS and DDRPOS.

Bidirectional associations between the duration and timing of nocturnal sleep and daytime naps in adolescents differ from weekdays to weekends.

Previous studies examining bidirectional relationships between nocturnal sleep and napping have focused on sleep duration, leaving a gap in our understanding of how sleep timing contributes. Here, we assessed the duration and timing for night sleep and daytime naps, to evaluate how the previous night's sleep influences the next day's napping, and how napping influences same-night nocturnal sleep. We analyzed sleep diary and actigraphy data from 153 teens (males = 43.8%, mean age = 16.6 years). Participants who never napped were excluded. Nocturnal sleep-nap relationships were investigated using logistic and linear regression models separately for weekdays and weekends. Participants napped an average of 2.3 times a week. 167 school day naps and 107 weekends were recorded. Naps were on average 82.12 ± 53.34 minutes and the average nap onset was 14:58 ± 3.78 hours. Their duration, start and end times did not significantly differ between weekdays and weekends. Nocturnal sleep duration did not predict next-day nap occurrence or duration. However, on school days, earlier wake times significantly increased the likelihood of napping that day, and advanced nap timing. On weekends, later bedtimes and wake times delayed nap timing. On school days, napping longer than one's average shortened nocturnal sleep whereas on weekends, waking from a nap later than one's average delayed bedtimes. Early wake times increase the likelihood of napping and advance the time of a nap that day. Naps may be detrimental to the same night's sleep only if they are long and occur late, as these can delay bedtimes and shorten nocturnal sleep duration, especially on school days. The Cognitive and Metabolic Effects of Sleep Restriction in Adolescents (NFS4), https://clinicaltrials.gov/study/NCT03333512, ID: NCT03333512. Investigating Preferred Nap Schedules for Adolescents (NFS5), https://clinicaltrials.gov/study/NCT04044885, ID: NCT04044885.

Allostatic Load Is Associated with Overuse Musculoskeletal Injury during US Marine Corps Officer Candidates School.

Overuse musculoskeletal injuries (MSKI) remain a significant medical challenge in military personnel undergoing military training courses; further understanding of the biological process leading to overuse MSKI development and biological signatures for injury risk are warranted. The purpose of this study was to determine the association between overuse MSKI occurrence and physiological characteristics of allostatic load characterized as maladaptive biological responses to chronic stress measured by wearable devices in US Marine Corps officer candidates during a 10-wk training course. Devices recorded energy expenditure (EE), daytime heart rate (HR), sleeping HR, and sleep architecture (time and percentage of deep, light, rapid eye movement sleep, awake time, total sleep). Flux was calculated as the raw or absolute difference in the average value for that day or night and the day or night beforehand. Linear mixed-effect model analysis accounting for cardiorespiratory fitness assessed the association between overuse MSKI occurrence and device metrics ( α = 0.05). Sixty-nine participants (23 females) were included. Twenty-one participants (eight females) sustained overuse MSKI. Overuse MSKI occurrence in male participants was positively associated with daytime HR ( β = 5.316, P = 0.008), sleeping HR ( β = 2.708, P = 0.032), relative EE ( β = 8.968, P = 0.001), absolute flux in relative EE ( β = 2.994, P = 0.002), absolute EE ( β = 626.830, P = 0.001), and absolute flux in absolute EE ( β = 204.062, P = 0.004). Overuse MSKI occurrence in female participants was positively associated with relative EE ( β = 5.955, P = 0.026), deep sleep time ( β = 0.664, P < 0.001), and percent deep sleep ( β = 12.564, P < 0.001) and negatively associated with absolute flux in sleeping HR ( β = -0.660, P = 0.009). Overuse MSKI occurrences were associated with physiological characteristics of allostatic load, including chronically elevated HR and EE and greater time in restorative sleep stages, which may serve as biological signatures for overuse MSKI risk.

The Effect of Using Anchored Wake Time to Derive 24-h Device Measured Circadian Physical Behavior Patterns.

Tailoring physical activity interventions to individual chronotypes and preferences by time of day could promote more effective and sustainable behavior change; however, our understanding of circadian physical behavior patterns is very limited. To characterize and compare 24-h physical behavior patterns expressed relative to clock time (the standard measurement of time-based on a 24-h day) versus wake-up time in a large British cohort age 46. Data were analyzed from 4979 participants in the age 46 sweep of the 1970 British Cohort Study who had valid activPAL accelerometer data across ≥4 days. Average steps and upright time (time standing plus time stepping) per 30-min interval were determined for weekdays and weekends, both in clock time and synchronized to individual wake-up times. The mean weekday steps were 9588, and the mean weekend steps were 9354. The mean weekday upright time was 6.6 h, and the mean weekend upright time was 6.4 h. When synchronized to wake-up time, steps peaked 1 h after waking on weekdays and 2.5 h after waking on weekends. Upright time peaked immediately, in the first 30-min window, after waking on both weekdays and weekends. Aligning accelerometer data to wake-up times revealed distinct peaks in stepping and upright times shortly after waking. Activity built up more gradually across clock time in the mornings, especially on weekends. Synchronizing against wake-up times highlighted the importance of circadian rhythms and personal schedules in understanding population 24-h physical behavior patterns, and this may have important implications for promoting more effective and sustainable behavior change.

Do Sleep Time and Duration Affect the Development of Prehypertension in Undergraduate Medical Students? An Experience from a Tertiary Care Hospital in Kolkata

Abstract Introduction and Objective Hypertension is an evolving public health challenge at present, and it is preceded by a prehypertensive stage. Irregular sleep duration and pattern have been found to be linked with cardiovascular diseases. Medical students are highly vulnerable to low quality sleep due to pressure regarding the academic curriculum and poor lifestyle. The present study aimed to estimate the prevalence of prehypertension, describe the risk factors and sleep patterns of undergraduate medical students, and determine the association, if any, involving sleep time and duration and prehypertension. Materials and Methods Data was collected from 254 undergraduate medical students via the Pittsburgh Sleep Quality Index (PSQI) questionnaire and a self-structured questionnaire. The frequency of events was established and the Chi-squared and t-tests were applied to determine the association. Finally, regression analysis was performed to determine the correlation. Results Male sex, high body mass index (BMI), poor sleep quality, and night sleep duration shorter than 5 hours were found to be significant risk factors for the development of prehypertensive condition (prevalence of 42.5%). However, there were no statistically significant associations regarding prehypertension and family history, junk food and salt intake, physical activity and daytime napping, bedtime, and wake-up time. Night sleep duration shorter than 5 hours presented an odds ratio of 4.713 (p = 0.010) for the development of prehypertension after adjusting for other risk factors, such as male sex, sleep quality, and high BMI. Discussion and Conclusion A high prevalence of prehypertension (42.5%) was noted among undergraduate medical students. Night sleep duration shorter than 5 hours was a significant risk factor for the development of prehypertension, whereas sleep time was not significantly associated with prehypertension.

Sleep disturbance associated with the menopause.

Sleep disturbance is one of the most common and debilitating symptoms experienced by women during the menopause transition. However, there are currently no therapies specifically approved for sleep disturbance associated with the menopause. Here, we consider how to characterize sleep disturbance associated with the menopause and discuss its etiology, including the latest advances in our understanding of the neuronal circuits that regulate reproduction, body temperature, sleep, and mood; and reflect on its impact on women's health and well-being. We also examine the current treatment landscape and look to the future of treatment for this condition. We conducted a review of the literature and combined this with discussion with experts in the fields of sleep and menopause as well as experiences from our own clinical practices. Sleep disturbance associated with the menopause is characterized by frequent night-time awakenings and increased awake time after sleep onset. Its impacts are wide-ranging, negatively affecting health as well as personal and social relationships, productivity, and work performance. There is currently an unmet need for effective, safe, and well-tolerated treatments to address this important symptom, and wider recognition of the association between sleep disturbances and the menopause is needed. Sleep disturbances associated with the menopause can result from hormone changes as well as vasomotor and mood symptoms. Growing research has contributed to our knowledge of the role of hypothalamic estrogen-sensitive kisspeptin/neurokinin B/dynorphin neurons. These neurons are thought to integrate the gonadotropin-releasing hormone pathway and the pathways responsible for the homeostatic control of body temperature and the circadian regulation of sleep-wake cycles. Understanding these neurons offers the potential to create treatments that target a key cause of sleep disturbance associated with the menopause. Further research to understand their etiology and characterize the neuronal circuits responsible could benefit the development of these targeted treatment approaches.

Associations of actigraph sleep characteristics with blood pressure among older adults

ObjectivesMany studies have examined links between sleep and blood pressure, with mixed findings, mostly using self-reported sleep data and cross-sectional designs. We examined whether actigraph-estimated sleep characteristics are associated with concurrent blood pressure or 5-year blood pressure change in a national cohort of older adults (National Social Life, Health and Aging Project), and whether these associations differ by hypertension medication use. MethodsSubjects were 669 older adults (62-90years), 471 with 5-year follow-up data. Sleep characteristics were duration (linear plus quadratic terms); sleep percentage; and categorical onset, midpoint, and waking times. Multivariable linear models adjusted for age, race, gender, obesity, smoking, daytime napping, and hypertension medication use. Interactions between sleep characteristics and hypertension medication were tested among the 401 subjects with consistent hypertension medication status over time. ResultsWe found U-shaped cross-sectional and longitudinal relationships between duration and blood pressure, with shorter and longer sleep times associated with higher blood pressure. Later onset times were cross-sectionally associated with higher systolic blood pressure, while earlier onset times were longitudinally associated with systolic blood pressure increase. Midpoint, wake time, and sleep percentage were not significantly associated with blood pressure. Significant interaction terms suggested hypertension medications attenuated associations of sleep onset and wake time with diastolic blood pressure. ConclusionsThese results with actigraph-estimated parameters confirm some, but not all, associations reported from research based on self-reported sleep data. Our findings are consistent with recommended intermediate sleep durations for cardiovascular health and suggest hypertension medication use may attenuate some associations between sleep timing and blood pressure.

Later ("evening") circadian preference is associated with poorer executive, academic, and attentional functioning in adolescents with and without ADHD.

Adolescents vary considerably in their circadian phase preference; those with greater "eveningness" (also known as "night owls") have later bedtimes, wake times, and peak arousal compared to those with greater "morningness." Prior research suggests that (a) greater eveningness is associated with worse academic, executive, and attentional functioning; and (b) adolescents with attention-deficit/hyperactivity disorder (ADHD) tend to be high in eveningness and to have deficits in these school-related constructs. However, few studies have examined circadian preference alongside two potential confounds-sleep duration and sleep quality-as predictors of daytime functioning, or whether the strength of associations differs across adolescents with and without ADHD. Participants were 302 adolescents (Mage = 13.17 years; 44.7% female; 81.8% White); approximately half (52%) had ADHD. A multi-method, multi-informant design was used. Specifically, adolescents reported on their circadian preference, school night sleep duration, and sleep quality. Adolescents provided ratings of their academic motivation (intrinsic, extrinsic, and amotivation) and were administered standardized achievement tests in reading and math. Adolescents and parents completed ratings of daily life executive functioning (behavioral, emotion, and cognitive regulation), and they and teachers also provided ratings of ADHD inattentive symptoms. Above and beyond sleep duration, sleep quality, and covariates (sex, family income, pubertal development, medication use), greater eveningness was uniquely associated with poorer academic, executive, and attentional functioning across most measures. Sleep quality was uniquely associated with a handful of outcomes, and sleep duration was not significantly uniquely associated with any outcome in the regression analyses. ADHD status did not moderate effects. This study provides compelling evidence that poorer academic, executive, and attentional functioning are more closely associated with greater eveningness than with sleep duration or quality in adolescents. Findings suggest that targeting circadian preference may be important to reduce these problems in adolescents, especially in clinical samples such as ADHD for whom academic, executive, and attentional difficulties are exceptionally common.