Sleep Variables Research Articles

Objective and Subjective Intraindividual Variability in Sleep: Predisposing Factors and Health Consequences.

We investigated the factors that predispose or precipitate greater intraindividual variability (IIV) in sleep. We further examined the potential consequences of IIV on overall sleep quality and health outcomes, including whether these relationships were found in both self-reported and actigraphy-measured sleep IIV. In Study 1, 699 US adults completed a Sleep Intra-Individual Variability Questionnaire and self-reported psychosocial, sleep quality, and health outcomes. In Study 2, 100 university students wore actigraphy and completed psychosocial, sleep, and health surveys at multiple timepoints. In cross-sectional analyses that controlled for mean sleep duration, predisposing/precipitating factors to greater IIV were being an underrepresented racial/ethnic minority (Study 1: F = 13.95, p < .001; Study 2: F = 7.03, p = .009), having greater stress (Study 2: r values ≥ 0.32, p values ≤ .002) or trait vulnerability to stress (Study 1: r values ≥ 0.15, p values < .001), and showing poorer time management (Study 1: r values ≤ -0.12, p values ≤ .004; Study 2: r values ≤ -0.23, p values ≤ .028). In addition, both studies showed that greater sleep IIV was associated with decreased overall sleep quality, independent of mean sleep duration (Study 1: r values ≥ 0.20, p values < .001; Study 2: r values ≥ 0.33, p values ≤ .001). Concordance across subjective and objective IIV measures was modest ( r values = 0.09-0.35) and similar to concordance observed for subjective-objective mean sleep duration measures. Risk for irregular sleep patterns is increased in specific demographic groups and may be precipitated by, or contribute to, higher stress and time management inefficiencies. Irregular sleep may lead to poor sleep quality and adverse health outcomes, independent of mean sleep duration, underscoring the importance of addressing sleep consistency.

Sleep architecture of elite soccer players surrounding match days as measured by WHOOP straps

ABSTRACT This study aimed to quantify and compare sleep architecture before and after home and away matches in elite soccer players from the English Premier League. Across two seasons, 6 male players (age 28 ± 5 y; body mass 85.1 ± 9.5 kg; height 1.86 ± 0.09 m) wore WHOOP straps to monitor sleep across 13 matches that kicked off before 17:00 h. For each, sleep was recorded the night before (MD−1), after (MD) and following the match (MD +1). Across these 3 days total sleep time (TST), sleep efficiency (SE), sleep disturbances, wake time, light sleep, deep sleep, REM sleep, sleep and wake onsets, alongside external load, were compared. TST was reduced after MD versus MD +1 (392.9 ± 76.4 vs 459.1 ± 66.7 min, p = 0.003) but no differences existed in any other sleep variables between days (p > 0.05). TST did not differ after home (386.9 ± 75.7 min) vs. away matches (401.0 ± 78.3 min) (p = 0.475), nor did other sleep variables (p > 0.05). GPS-derived external load peaked on MD (p < 0.05). In conclusion, despite reduced TST on MD, sleep architecture was unaffected after matches played before 17:00 h, suggesting sleep quality was not significantly compromised.

A WeChat-based nursing intervention program improves the postoperative rehabilitation of breast cancer patients: results from a randomized controlled trial.

In postoperative setting, breast cancer (BC) patients can experience adverse effects, including fatigue, sleep disorders, and pain, which substantially affect their health-related quality of life (HRQoL). This study sought to assess the effectiveness of a WeChat-based multimodal nursing program (WCBMNP) that was specifically designed for the rehabilitation of women following BC surgery. BC patients were randomly, single-blinded allocated to either the intervention (n=62) or control (n=63) cohorts. Over a period of 6 months (24 weeks), the intervention cohort received a WCBMNP in addition to routine nursing care, while the control cohort received routine nursing care only. To evaluate patients' fear of cancer recurrence (FCR), their overall fear score was assessed using the Japanese version of the Concerns About Recurrence Scale (CARS-J) for primary outcome. The initial outcome (HRQoL) and secondary results, such as fatigue, sleep, and pain, were examined using the Functional Assessment of Cancer Therapy-Breast (FACT-B, version 4.0) and Nursing Rating Scale (NRS), respectively. Two hundred and ten participants, 85 participants were excluded. Compared to the controls (n=63), the intervention cohort (n=62) showed statistically significant improvements in their CARS-J scores. The intervention cohort aggregate scores on the FACT-B improved significantly but were affected by the compounding influences of cohort dynamics, temporal progression, and their interaction. Similar improvements were observed in the social/family and functional well-being domains. Emotional well-being was improved based on the effects of time and group-time interaction. In the intervention cohort, the "BC-specific subscale for additional concerns" was affected by group and time, whereas physical well-being was only affected by time. Conversely, there were no statistically significant changes in the variables of fatigue, sleep, and pain. The WCBMNP reduced FCR and significantly increased the HRQoL of female patients with BC postoperatively. The WCBMNP could be implemented as a postoperative rehabilitation intervention in this patient population to improve outcomes. Chinese Clinical Trial Registry (ChiCTR2400081557).

Impact of immersive virtual reality games or traditional physical exercise on cardiovascular and autonomic responses, enjoyment and sleep quality: a randomized crossover study

Objectives: To assess the potential of immersive virtual reality (IVR) in achieving moderate exercise intensity, and 2) to examine the acute effects of two IVR exergame sessions (BOXVR and Beat Saber), comparing them with the impact of traditional exercise on heart rate variability (HRV), perceived effort, delayed onset muscle soreness, motivation, and sleep. Materials and methods: A crossover design was used. The participants (n = 22) randomly performed two sessions of IVR and one session of moderate intensity physical activity, each session lasting 30 min. Heart Rate (HR) and HRV, Perceived Exertion Scale, Intrinsic Motivation Inventory, sleep quality, and perceived pain, were evaluated. Results: The cardiac response to the activities was significantly higher when participants performed traditional physical activity as compared to the BOXVR and Beat Saber games. Traditional training provided a different HRV response as compared to Beat Saber (LnRMSSD, p = 0.025; SDNN, p = 0.031). Although the sessions were planned for moderate intensity, BOXVR generated a moderate intensity (49.3% HRreserve), Beat Saber (29.6% HRreserve) a light one, and the Circuit session, a vigorous one (62.9% HRreserve). In addition, traditional training reported higher perceived exertion and pain with less enjoyment. Differences were observed between the exergames. BOXVR resulted in a lower cardiac response (HRmax and HRmean), and a higher perception of exertion and pain at 72 h. The sleep variables analyzed were not altered by any of the sessions. Conclusions: BOXVR and traditional training can lead to moderate intensity physical activity. However, traditional training could result in lower adherence to physical exercise programs, as it was perceived as more intense and less enjoyable.

D Tipi Kişilik, Uyku Vaktini Erteleme ve Uyku Kalitesi Arasındaki İlişki

Background/Aims: Bedtime procrastination (BP) is an unhealthy sleep behavior, but its relationship with Type D (distress) personality has never been examined. This study aimed to investigate the relationship between Type D Personality, BP, and Sleep Quality in university students.&#x0D; Methods: In this cross-sectional study, we applied the sociodemographic sleep data form, Type D personality scale (DS-14), Bedtime Procrastination Scale (BPS), Pittsburgh Sleep Quality Index (PSQI) (subjective sleep quality and daytime dysfunction subscales), Insomnia Severity Index (ISI), and Epworth Sleepiness Scale (ESS). All participants were divided into two groups: Type D personality and non- Type D personality. Sleep variables and scales were compared between these two groups. Additionally, correlation analysis was performed between the scales and the subdimensions of Type D personality.&#x0D; Results: We completed our study with 209 university students (66%, n = 138 female and 34%, n=71 male). The mean age was 22.17 ± 4.33, and 51.2% of all participants had Type D personality. Sleep quality was poor, and insomnia was more severe in participants with Type D personality. Participants with Type D personality had more delayed bedtime. Negative affectivity was associated with poor sleep quality, more severe insomnia, and BP, but social inhibition was not associated with BP.&#x0D; Conclusion: Clinicians should consider the negative affectivity sub-dimension of Type D personality contributing to BP behavior among university students when planning interventions to reduce BP behavior.

The Impact of Screen Time on Sleep Patterns in School-Aged Children: A Cross-Sectional Analysis.

In a world filled with technology, there's concern about the impact of screen time on children and teenagers. A recent study of 11,875 children aged nine to 10 in the US explored how screen time affects mental health, behaviour, school performance, sleep, and friendships. The results indicate that more screen time is mildly linked to worse mental health, more behaviour problems, lower academic performance, and poorer sleep, but slightly better peer relationships. However, these connections were weak, with socioeconomic status (SES) having a stronger influence on these outcomes. The study doesn't prove that screen time causes these issues, suggesting that increased screen time might not be directly harmful to children in this age group. The research adds to the understanding of how screen time impacts children's well-being and highlights the importance of promoting healthy habits. Our study aims to add to this literature by examining how screen time impacts sleep quality, dream recall, and academic performance in school-aged children. Understanding the potential consequences of screen time is crucial for promoting healthy habits and ensuring the overall well-being of children. Our research seeks to provide further insights into the relationship between screen time and key aspects of children's lives as its prevalence continues to rise. The research incorporates a cohort of 1000 school-aged children, bifurcated evenly into two categories based on their daily screen exposure: a low screen time group (less than one hour daily, n = 500) and a high screen time group (over three hours daily, n = 500). The study probes into the correlation between screen time and various health parameters, such as sleep patterns, dream recall, and academic prowess. The analysis showed that children with low screen time had better sleep efficiency (90% vs. 75%), more frequent dream recall (70% vs. 30%), fewer nocturnal awakenings (0.5 vs. 1.5 times weekly), less daytime sleepiness (20% vs. 60%), and higher physical activity levels (60 vs. 30 minutes per day) compared to those with high screen time. They also had less weekend sleep variability (1.2 hours) and a lower risk of circadian rhythm disturbances (20% increased risk in the high screen time group). Additionally, a screen-free bedroom was more common in the low screen time group (85% vs. 30%), and parental involvement in sleep routines was higher (90% vs. 40%). Academically, the low screen time group achieved higher grades ('A' to 'A+' vs. 'B'), and they had more face-to-face social interactions (two vs. one hour per day). Escalating screen time is correlated with detrimental impacts on sleep efficiency, dream recall, physical activity, circadian rhythms, and academic performance in school-aged children. Fostering a screen-free bedroom environment and augmenting parental involvement in sleep routines may alleviate these adverse effects.

The early-stage impacts of shock events on adult sleep: Lessons from the COVID-19 pandemic.

The present study aims to estimate the early-stage association of the coronavirus disease 2019 (COVID-19) pandemic with sleep duration, 4months after the initial outbreak, at a national level. Using the China Family Panel Studies in 2018 and its follow-up in 2020, 16,563 adult participants were analyzed in our study. The first wave transmissibility of the COVID-19 pandemic in mainland China was used as a quasi-natural experiment. The difference in difference method was employed to compare variations across participants interviewed before or after the pandemic and between groups from provinces with different COVID-19 severity. The study observed a decline in workday sleep duration among adults, regardless of their employment status. Specifically, working adults experienced a significant decrease in sleep duration on work days (-1.54, 95% confidence interval -2.16 to -0.92), alongside an increase on work-free days (2.41, 1.56-3.24), leading to a wider sleep discrepancy in sleep patterns (3.95, 3.31-4.59). Noteworthy, working-age adults (-2.00, -2.79 to -1.22) and males (-3.31, -4.31 to -2.30) exhibited greater sleep decreases on work days, whereas females exhibited a more pronounced disparity in sleep patterns (6.18, 4.73-7.63) between work and work-free days. The pandemic is significantly associated with prolonged changes in adults' sleep duration, including sleep decreases on work days and catch-up sleep on work-free days for working adults. To prepare for future global emergencies, the government may need to promote resilience to mitigate the pandemic's adverse impacts on the working population. Guaranteeing adequate sleep among working adults and reducing sleep debt should be prioritized in such efforts.

Dysregulated 24 h melatonin secretion associated with intrinsically photosensitive retinal ganglion cell function in diabetic retinopathy: a cross-sectional study.

The aim of this study was to explore whether diabetic retinopathy is associated with alterations of the circadian system, and to examine the role of reduced intrinsically photosensitive retinal ganglion cell (ipRGC) function. Participants with type 2 diabetes, with diabetic retinopathy (n=14) and without diabetic retinopathy (n=9) underwent 24 h blood sampling for melatonin and cortisol under controlled laboratory conditions. ipRGC function was inferred from the post-illumination pupil response (PIPR). Habitual sleep duration, efficiency and variability were assessed by actigraphy. Participants with diabetic retinopathy compared to participants without diabetic retinopathy had smaller PIPR (p=0.007), lower 24 h serum melatonin output (p=0.042) and greater day-to-day sleep variability (p=0.012). By contrast, 24 h cortisol profiles, sleep duration and efficiency were similar in both groups. Six individuals with diabetic retinopathy had no detectable dim-light melatonin onset. PIPR correlated with 24 h mean melatonin levels (r=0.555, p=0.007). ipRCG dysfunction in diabetic retinopathy is associated with disruptions of the 24 h melatonin rhythm, suggesting circadian dysregulation in diabetic retinopathy.

Sleep physiology in patients with epilepsy: Influence of seizures on rapid eye movement (REM) latency and REM duration.

A well-established bidirectional relationship exists between sleep and epilepsy. Patients with epilepsy tend to have less efficient sleep and shorter rapid eye movement (REM) sleep. Seizures are far more likely to arise from sleep transitions and non-REM sleep compared to REM sleep. Delay in REM onset or reduction in REM duration may have reciprocal interactions with seizure occurrence. Greater insight into the relationship between REM sleep and seizure occurrence is essential to our understanding of circadian patterns and predictability of seizure activity. We assessed a cohort of adults undergoing evaluation of drug-resistant epilepsy to examine whether REM sleep prior to or following seizures is delayed in latency or reduced in quantity. We used a spectrogram-guided approach to review the video-electroencephalograms of patients' epilepsy monitoring unit admissions for sleep scoring to determine sleep variables. In our cohort of patients, we found group- and individual-level delay of REM latency and reduced REM duration when patients experienced a seizure before the primary sleep period (PSP) of interest or during the PSP of interest. A significant increase in REM latency and decrease in REM quantity were observed on nights where a seizure occurred within 4 h of sleep onset. No change in REM variables was found when investigating seizures that occurred the day after the PSP of interest. Our study is the first to provide insight about a perisleep period, which we defined as 4-h periods before and after the PSP. Our results demonstrate a significant relationship between seizures occurring prior to the PSP, during the PSP, and in the 4-h perisleep period and a delay in REM latency. These findings have implications for developing a biomarker of seizure detection as well as longer term seizure risk monitoring.

Preventive noninvasive vagal nerve stimulation reduces insufficient sleep-induced depression by improving the autonomic nervous system

BackgroundDepression is closely linked to an imbalance in the autonomic nervous system (ANS). However, the role of this imbalance in mediating the effects of sleep deprivation (SD) and vagus nerve stimulation (VNS) on emotional well-being is not fully understood. MethodsA population-based analysis was conducted to explore the relationship between sleep duration, depression scores, and heart rate variability (HRV). Additionally, the chronic SD mouse model was established to assess the impact of preventive transcutaneous auricular VNS (taVNS) on pathological and behavioral changes. ResultsOur study found a significant link between sleep duration, depression severity, and HRV. Shorter sleep duration was associated with higher depression scores and lower RMSSD (a measure of HRV). In our rat model, insufficient sleep consistently impaired HRV. This effect was mitigated by taVNS, accompanied by corresponding changes in levels of IL-1β and IL-6, astrocyte and microglia activation, and tail suspension times. ConclusionsUsing VNS as a preventive treatment for depression-risk individuals with insufficient sleep shows promise. It not only broadens the potential applications of VNS but also sheds light on its mechanism—particularly its role in enhancing vagal nerve function and balancing the ANS, as evidenced by HRV measurements.

Home-Based Aerobic Interval Training Combined with Resistance Training Improved Daytime Dysfunction in Adults with Obesity and Sleep-Disordered Breathing

Abstract Introduction There have been many barriers to exercising at a gym due to the coronavirus disease 2019 (COVID-19) pandemic worldwide. Home-based aerobic interval training (AIT) combined with resistance training (RT) may be helpful for obese adults with sleep-disordered breathing (SDB) to overcome those barriers and improve their subjective sleep disorders. Thus, the present study aimed to examine the effects of home-based AIT combined with RT on subjective sleep disorders in obese adults with SDB. Material and Methods This study has a one-group pretest-posttest design. Twenty-one adults with obesity and SDB were assigned to perform 8 weeks of AIT combined with RT. Subjective sleep disorder variables including the Pittsburgh Sleep Quality Index (PSQI), Berlin Questionnaire, and Epworth Sleepiness Scale were defined as primary outcomes. Anthropometric variables, physical fitness components, and blood biomarkers were assigned as secondary outcomes. All outcome measurements were examined at baseline and after 8 weeks of training. Results Daytime dysfunction of PSQI was significantly improved after 8 weeks of the exercise program (p &lt; 0.05). Upper and lower chest expansion and estimated maximum oxygen consumption were significantly increased after 8 weeks of the exercise program (all p &lt; 0.05). None of the blood biomarkers changed after 8 weeks of training. Conclusion This study suggests that home-based AIT combined with RT effectively alleviates daytime dysfunction and seems to be more helpful in improving global PSQI in adults with obesity. Future studies with a larger sample size, under a controlled trial are recommended to prove the benefits of the exercise program.

Association between Social Jetlag and Objective Physical Activity among Female University Students of Japan: A Cross-Sectional Study

Abstract Objective Discrepancies between sleep timing on work/school and free days, also known as social jetlag (SJL), can cause health problems. These issues occur most often in individuals from adolescence to the early 20s, which is equivalent to the age of university students. This study was designed to explore the recommended level of physical activity required to minimize SJL and to examine the relationship between SJL and objective physical activity among female university students. Methods We assessed the SJL of 68 female students using the Japanese version of the Munich Chronotype Questionnaire. The objective physical activity and sleep variables of subjects were also evaluated at 3 to 4 weeks using a small triaxial accelerometer. Results A significant negative correlation was found between SJL and physical activity on both free (r = − 0.435, p &lt; 0.001) and school days (r = − 0.341, p &lt; 0.01). According to the linear regression analysis, physical activity of 11,174 steps on school days and 10,713 steps on free days had the lowest SJL value. Total sleep time on free days had a significant positive correlation with SJL (r = 0.399, p &lt; 0.001) and a negative correlation with physical activity (r = − 0.520, p &lt; 0.001). Discussion Our results suggest that substantial SJL may cause chronic fatigue and lead to a low level of physical activity in female university students. These results also imply that the recommended level of physical activity necessary to minimize SJL among these students is around 11,000 steps on both school and free days.

Shorter self-reported sleep duration is associated with worse virtual spatial navigation performance in men.

Sleep has been shown to impact navigation ability. However, it remains unclear how different sleep-related variables may be independently associated with spatial navigation performance, and as to whether gender may play a role in these associations. We used a mobile video game app, Sea Hero Quest (SHQ), to measure wayfinding ability in US-based participants. Wayfinding performance on SHQ has been shown to correlate with real-world wayfinding. Participants were asked to report their sleep duration, quality, daytime sleepiness and nap frequency and duration on a typical night (n = 766, 335 men, 431 women, mean age = 26.5years, range = 18-59years). A multiple linear regression was used to identify which self-reported sleep variables were independently associated with wayfinding performance. Shorter self-reported sleep durations were significantly associated with worse wayfinding performance in men only. Other self-reported sleep variables showed non-significant trends of association with wayfinding performance. When removing non-typical sleepers (< 6 or > 9h of sleep on a typical night), the significant association between sleep duration and spatial navigation performance in men was no longer present. These findings from U.S.-based participants suggest that a longer self-reported sleep duration may be an important contributor to successful navigation ability in men.

Patterns in behavioural sleep variables and social jetlag in elderly people of Western Odisha

ABSTRACT In humans, sleep is an essential physiological process for life and survival. The main objective of the current study is to determine the behavioural sleep patterns and social jetlag in elderly adults. The second objective is to define the relationship among subjective sleep quality, mid-sleep timings, social jetlag, and sunlight exposure. We recruited 945 female and 1047 male participants aged ≥ 60 years from 65 rural villages in the Sambalpur district of Odisha, India. The Munich Chrono Type Questionnaire (MCTQ) is a self-reported questionnaire that measures a person’s behavioral sleep variables, including social jetlag and chronotype, whereas the Pittsburgh Sleep Quality Index (PSQI) measures the subjective sleep quality of an individual. We employed MCTQ and PSQI to obtain behavioral sleep variables and subjective sleep quality in the recruited subjects. The behavioral sleep variables were compared using a paired t-test on both work and work-free days. In addition, the behavioral sleep variables as a function of gender were compared using an independent Student’s t-test. In the current study, most of the elderly individuals reported both midpoint of sleep on workdays (MSW) and midpoint of sleep on work-free days (MSF) between 00:01–03:00. The averages of mid-sleep timings between workdays and work-free days were not statistically significant. Data on MSFsc (midpoint of sleep on work-free days sleep corrected) indicated that most elderly adults (99.6%) are morning type; they go to bed early and wake up early. The elderly participants from the rural population of Sambalpur district in western Odisha had the least social jetlag and exhibited good subjective sleep quality. It would be worthwhile to find out the determinants of these positive features apropos social jetlag and behavioural sleep patterns.

Effects of REM Sleep and systolic blood pressure variability on five-year cardiovascular disease risk

Effects of REM Sleep and systolic blood pressure variability on five-year cardiovascular disease risk

Sleep and glycemic variability in people with diabetes: A systematic review

Sleep and glycemic variability in people with diabetes: A systematic review

EFFECTS OF A SINGLE EVENING VINYASA YOGA SESSION ON SLEEP IN ADULTS WITH INSOMNIA SYMPTOMS

https://youtu.be/1I7CENnICb4 BACKGROUND Vinyasa yoga (VY), a form of yoga that links breath with movement and has higher energy expenditure perhaps than most other types of yoga, has been sparsely studied for its effects on sleep among adults with insomnia. It remains unknown whether and how an acute bout of VY performed in the evening impacts sleep and autonomic function. The purpose of this study it to examine the effects of an acute session of VY performed in the evening on sleep and nocturnal heart rate variability (HRV) in adults with insomnia symptoms. METHODS 33 insufficiently active adults (84.8% female; 78.8% White; age=34.9±10.6 y; body mass index=28.9 kg/m2) with at least mild insomnia symptoms (Insomnia Severity Index ≥ 10) were randomized to either a single 60-min session of VY (n=17) or a quiet rest control condition (CON: n=16) occurring between 15:00 and 20:00 h. VY followed a pre-recorded practice and CON watched a nature documentary. On one night before and after the experimental session, participants wore a wrist accelerometer and a chest heart rate (HR) monitor overnight and completed a sleep diary. HRV was derived from the entire HR recording across the nocturnal period and standardized for sleep duration, with root mean square of successive differences (RMSSD) as the primary outcome. Analyses compared the changes from pre- to post-session between groups using linear mixed models and Cohen’s d effect sizes. RESULTS The change in actigraphy-assessed sleep efficiency (SE) and total sleep time (TST) did not differ from pre- to post-session for VY (SE: 88.9±1.4 to 88.9±1.5%; TST: 454.7±15.8 to 445.8±17.4 min) or CON (SE: 89.4±1.4 to 88.7±1.6%; TST: 401.3±16.3 vs. 407.3±17.3 min); group x time interactions were not statistically significant (each p &amp;gt; 0.48). The change in nocturnal RMSSD did not differ from pre- to post-session for either VY (39.5±6.8 to 38.7±6.0 ms) or CON (37.6±7.0 to 35.8±6.2 ms) and the group x time interaction was not statistically significant (p=0.94). CONCLUSION An acute bout of VY performed in the early evening did not significantly change accelerometer- or diary-assessed sleep or impact parasympathetic tone during sleep. VY in the early evening is unlikely to benefit or impair sleep in adults with insomnia symptoms.

Sleep and Caregiver Burden Among Caregivers of Persons Living With Dementia: A Scoping Review.

Caregivers of persons with dementia report worse sleep when compared to the general population. The objective of this review was to synthesize evidence regarding the link between caregiver burden and dementia caregivers' sleep. We conducted a scoping review using a systematic search for pertinent literature in PubMed, CINAHL, and Web of Science through March 2022. Keywords included content areas of dementia, caregiver burden, and sleep. Inclusion criteria were informal caregivers of persons living with dementia, a measured relationship between informal dementia caregiver sleep and subjective caregiver burden variables, and original research. Non-English studies were excluded. Extracted data were organized in tables, compared, and synthesized. The search yielded 540 nonduplicate articles screened by title and abstract; 118 full-text articles were reviewed; 24 were included. Most studies were cross-sectional, with variable sample sizes. Dementia caregivers had significantly poorer overall perceived sleep than noncaregivers across 4 studies that examined self-reported sleep measures. Eighteen studies investigated the association between caregiver burden and self-reported sleep quality, with 14 reporting a significant positive association between caregiver burden and self-reported sleep quality, and 4 finding null results. Only 2 of the 4 studies reporting the association between caregiver burden and objective sleep parameters (ie, actigraphy and polysomnography) reported a significant positive association for at least one sleep subdomain. Although subjective sleep quality is commonly affected by dementia caregiving burden, there is a lack of corresponding evidence on the relationship between burden and objective sleep metrics. Healthcare providers should consider the dementia caregiver burden's impact on sleep and regularly assess caregivers' sleep difficulties. Future studies should focus on consistently measuring caregiver burden and sleep to promote dementia caregiver health and well-being.

Effects of daily fluctuations in seep and intraindividual sleep variability on mood, motivation and sleepiness in university students: a wearable and digital diary approach

Effects of daily fluctuations in seep and intraindividual sleep variability on mood, motivation and sleepiness in university students: a wearable and digital diary approach

Impact on health outcomes associated with changing the clock 1 hour during fall and spring transitions in the Southern Hemisphere.

Changing the clocks seasonally is potentially harmful because it interferes with normal daytime activities. Studies aimed at quantifying this association are scant. The objective of this study was to determine the effects of 1 year's worth of changing the clocks (fall and spring transitions) on healthy young men located in the Southern Hemisphere in South America. We performed an observational prospective study. Thirty healthy male university students were evaluated from 2 weeks before to 2 weeks after both the fall and spring transitions. We administered an overall sleep questionnaire, assessed quality of life, recorded 7-day wrist actigraphy, and had participants perform a psychomotor vigilance task. We defined the 1-hour clock change as the primary exposure and the change in psychomotor vigilance task lapses of 500 milliseconds or more in response time as our primary outcome. Changes were evaluated by the Wilcoxon rank test (significance: P < .05). After the fall transition, we found a significant worsening in psychomotor vigilance task performance (median [interquartile range], 9.9 [6.0-14.3] lapses of ≥ 500 milliseconds in response time at baseline vs 16.8 [8.2-28.0] after transition; P < .002). Additionally, we found a median loss of about 1 hour of total sleep time and time in bed after the fall transition. Furthermore, participants presented with insomnia. Performance on the psychomotor vigilance task was also affected after the spring transition (16.7 [10-23] vs 23 [12.2-32.2]; P < .001). A decrease in performance in neurocognitive tests was found after both time transitions. The transition led to insomnia and a significant worsening of sleep variables. Labarca G, Henriquez-Beltrán M, Sanhueza R, etal. Impact on health outcomes associated with changing the clock 1 hour during fall and spring transitions in the Southern Hemisphere. J Clin Sleep Med. 2024;20(6):887-893.