Earlier Sleep Timing Research Articles

Sleep timing and the prevalence of hypertension in middle-aged and older populations: the sleep heart health study

ObjectivesSleep characteristics such as duration, continuity, and irregularity are associated with the risk of hypertension. This study aimed to investigate the association between sleep timing (including bedtime, wake-up time, and sleep midpoint) and the prevalence of hypertension.MethodsParticipants were selected from the Sleep Heart Health Study (n = 5504). Bedtime and wake-up times were assessed using sleep habit questionnaires. The sleep midpoint was calculated as the halfway point between the bedtime and wake-up time. Restricted cubic splines and logistic regression analyses were performed to explore the association between sleep timing and hypertension.ResultsA significant nonlinear association was observed between bedtime (Poverall<0.001; Pnonlinear<0.001), wake-up time (Poverall=0.024; Pnonlinear=0.076), sleep midpoint (Poverall=0.002; Pnonlinear=0.005), and the prevalence of hypertension after adjusting for potential confounders. Multivariable logistic regression showed that both late (> 12:00AM and 23:01PM to 12:00AM) and early (≤ 22:00PM) bedtimes were associated with an increased risk of hypertension compared to bedtimes between 22:01PM and 23:00PM. In addition, individuals with late (> 7:00AM) and early (≤ 5:00AM) wake-up times had a higher prevalence of hypertension than those with wake-up times ranging between 5:01AM and 6:00AM. Delaying the sleep midpoint (> 3:00AM) was also associated with an increased risk of hypertension. Furthermore, no significant interaction effect was found in the subgroup analyses stratified by age, sex, or apnea-hypopnea index.ConclusionsOur findings identified a nonlinear association between sleep timing and hypertension. Individuals with both early and late sleep timing had a high prevalence of hypertension.

Weekday and weekend sleep times across the human lifespan: a model-based simulation.

The shifts in the opposite directions, toward later and earlier sleep timing, occur during the transition through adolescence and adulthood, respectively. Such a n-shape of age-associated change in sleep timing does not resemble the inverse relationship of sleep duration with ages. Age-associated variation in the parameters of the mechanisms of circadian and homeostatic regulation of sleep would underlie these different shapes of relationship of sleep times with ages. Here, we searched for a parsimonious explanation of these different shapes by simulating sleep times on weekdays and weekends with one of the variants of the two-process model of sleep regulation. Using mean age of a sample with reported sleep times on weekdays and weekends, the whole set of 1404 such samples was subdivided into 15 age subsets. Simulations of sleep times in these subsets were performed with and without the suggestion of age-associated variation in the circadian phase. Simulations showed that the age-associated decay of slow-wave activity can parsimoniously explain not only the parallel decreases in weekend sleep duration and rate of the buildup of sleep pressure during the wake phase of the sleep-wake cycle, but also both the delay and advance of sleep timing during the transition through adolescence and adulthood, respectively. The almost functional relationships were revealed between the age-related changes in sleep duration, rate of the buildup of sleep pressure, and slow-wave activity that is a good electrophysiological marker of cortical metabolic rate and synaptic density, strength and efficacy.

346 Multimodal assessment of sleep in individuals with chronic post-concussive symptoms: A Pilot Study

OBJECTIVES/GOALS: Weaimed to compare subjective and objective sleep in individuals with chronic post-concussive symptoms. We hypothesized an association between self-reported sleep quality and objective sleep parameters, which is different for concussed and control cohorts. METHODS/STUDY POPULATION: 28 individuals with chronic post-concussive symptoms and 13 age-matched controls (no concussion history) completed the ISI, PSQI, PROMIS Depression, Anxiety, Stress and Cognitive questionnaires at enrollment. Objective sleep parameters were obtained for a minimum of 7 days and up to 30 days with a validated sleep monitoring device placed under the subject’s bed (Emfit). For each night, raw activity data per minute were analyzed to determinein-bed, sleep, wake, andout-of-bedtimes. These measures were used to calculate total sleep time (TST), sleep onset latency (SOL), and wake after sleep onset (WASO) for each night. RESULTS/ANTICIPATED RESULTS: Concussed individuals reported worse sleep with PSQI and ISI scores significantly higher than controls. They also showedsignificant associations between PSQI and Dep ression, ISI and Depression, and ISI and Anxiety scores. There was no difference between objective sleep parameters in the concussed and control cohorts (in-bed/sleep/wake/out-of-bed times, TST, SOL, and WASO). Instead, higher PSQI, ISI, Depression, Anxiety, and Stress scores (greater symptom burden) were all associated with later sleep times, where as higher Cognitive scores (greater cognitive function) were associated with earlier sleep times, regardless of group status. DISCUSSION/SIGNIFICANCE: Concussed individuals report worse subjective sleep but no differences to controls when objectively assessing sleep. Depression/anxiety, and not concussion status, determine objective sleep parameters. Psychiatric comorbidities should inform the treatment of post-concussive sleep disturbances.

DAILY ASSOCIATIONS OF SOCIAL INTERACTIONS WITH OBJECTIVE SLEEP MEASURES AMONG OLDER ADULTS

Abstract Disturbed sleep is a common problem and can have profound effects on older adults. Social relationships are known to be associated with quantity and quality of sleep. To extend prior research, we examined the associations of daily social interactions and sleep, using objective sleep measures and an ecological momentary assessments (EMA) approach. Participants in the Einstein Aging Study (n=285, Mage=77, range=70-90, 68% women, 46% White, 40% Black) reported their recent social interactions and physical contact four times a day for 16 days via EMA on mobile phones. Objective sleep measures (sleep timing, night sleep time, wake after sleep onset (WASO), sleep maintenance efficiency) were calculated from concurrent wrist actigraphy. Multilevel models controlled for demographics, living arrangement, Instrumental Activities of Daily Living, sleep-disordered breathing, and hypoxemia. Results showed that, on days when older adults had more day-time social interactions than their average, they had earlier sleep timing, shorter night sleep time, and less WASO, but no differences in sleep efficiency. On days when older adults had more physical contact than their average, they had earlier sleep timing and shorter night sleep time but no differences in WASO or sleep efficiency. These micro-longitudinal analyses among older adults suggest that daily social interactions are related to subsequent earlier sleep timing and shorter sleep at night, and can be beneficial for sleep quality. Physical contact seemed to be only associated with the timing and quantity of sleep but not sleep quality. Potential benefits of using an EMA approach in sleep research will be discussed.

The association between cortical gyrification and sleep in adolescents and young adults.

Healthy sleep is important for adolescent neurodevelopment, and relationships between brain structure and sleep can vary in strength over this maturational window. Although cortical gyrification is increasingly considered a useful index for understanding cognitive and emotional outcomes in adolescence, and sleep is also a strong predictor of such outcomes, we know relatively little about associations between cortical gyrification and sleep. We aimed to identify developmentally invariant (stable across age) or developmentally specific (observed only during discrete age intervals) gyrification-sleep relationships in young people. A total of 252 Neuroimaging and Pediatric Sleep Databank participants (9-26 years; 58.3% female) completed wrist actigraphy and a structural MRI scan. Local gyrification index (lGI) was estimated for 34 bilateral brain regions. Naturalistic sleep characteristics (duration, timing, continuity, and regularity) were estimated from wrist actigraphy. Regularized regression for feature selection was used to examine gyrification-sleep relationships. For most brain regions, greater lGI was associated with longer sleep duration, earlier sleep timing, lower variability in sleep regularity, and shorter time awake after sleep onset. lGI in frontoparietal network regions showed associations with sleep patterns that were stable across age. However, in default mode network regions, lGI was only associated with sleep patterns from late childhood through early-to-mid adolescence, a period of vulnerability for mental health disorders. We detected both developmentally invariant and developmentally specific ties between local gyrification and naturalistic sleep patterns. Default mode network regions may be particularly susceptible to interventions promoting more optimal sleep during childhood and adolescence.

Associations between light exposure and sleep timing and sleepiness while awake in a sample of UK adults in everyday life

Experimental and interventional studies show that light can regulate sleep timing and sleepiness while awake by setting the phase of circadian rhythms and supporting alertness. The extent to which differences in light exposure explain variations in sleep and sleepiness within and between individuals in everyday life remains less clear. Here, we establish a method to address this deficit, incorporating an open-source wearable wrist-worn light logger (SpectraWear) and smartphone-based online data collection. We use it to simultaneously record longitudinal light exposure (in melanopic equivalent daylight illuminance), sleep timing, and subjective alertness over seven days in a convenience sample of 59 UK adults without externally imposed circadian challenge (e.g., shift work or jetlag). Participants reliably had strong daily rhythms in light exposure but frequently were exposed to less light during the daytime and more light in pre-bedtime and sleep episodes than recommended [T. M. Brown et al., PLoS Biol. 20, e3001571 (2022)]. Prior light exposure over several hours was associated with lower subjective sleepiness with, in particular, brighter light in the late sleep episode and after wake linked to reduced early morning sleepiness (sleep inertia). Higher pre-bedtime light exposure was associated with longer sleep onset latency. Early sleep timing was correlated with more reproducible and robust daily patterns of light exposure and higher daytime/lower night-time light exposure. Our study establishes a method for collecting longitudinal sleep and health/performance data in everyday life and provides evidence of associations between light exposure and important determinants of sleep health and performance.

Associations of actigraphy-assessed sleep variables with adiposity and serum cardiometabolic outcomes in emerging adults.

This study assessed associations of actigraphy-assessed sleep with adiposity and serum cardiometabolic outcomes in emerging adults, and whether sex and race modified these associations. Data on 147 emerging adults (age = 19.4 ± 1.3 years; body mass index = 26.4 ± 7.0 kg m-2 ; 59% female; 65% White) from RIGHT Track Health were used. Actigraphy-based sleep measures included sleep duration, sleep efficiency, sleep timing midpoint, day-to-day sleep duration and sleep timing midpoint variability. Combined sleep duration and sleep timing behaviours were also derived (early-bed/late-rise, early-bed/early-rise, late-bed/late-rise, late-bed/early-rise). Outcomes included body mass index and BodPod-assessed fat mass index, fasting serum leptin, C-reactive protein, and homeostatic model assessment-insulin resistance. Sleep duration was 5.4 h per night. We noted an inverse association between sleep duration and homeostatic model assessment-insulin resistance. The early-bed/early-rise group had greater body mass index, C-reactive protein and homeostatic model assessment-insulin resistance compared with the early-bed/late-rise group (referent). Sex modified associations of sleep efficiency with C-reactive protein; stratified results revealed positive association between sleep efficiency and C-reactive protein in males, but not females. Race modified associations of sleep duration with body mass index and leptin, and of sleep duration variability with C-reactive protein. Stratified analyses revealed inverse associations between sleep duration with body mass index and leptin in Black, multiracial/other race individuals only. Positive association between sleep duration variability and C-reactive protein was noted in White individuals only. Shorter sleep duration, particularly when combined with earlier sleep timing, is associated with greater adiposity and serum cardiometabolic outcomes. Additional studies are needed to assess individual- and contextual-level factors that may contribute to sex and race differences in sleep health and cardiometabolic risk in emerging adults.

Associations of time in bed and sleep timing with dementia and cognitive decline among Chinese rural‐dwelling older adults: A cohort study

AbstractBackgroundThe longitudinal associations of time in bed (TIB) (a composite indicator of sleep duration, latency, and fragmentation) and sleep timing (a marker of circadian rhythms) with dementia and cognitive decline in older adults are unclear.MethodThis population‐based cohort study used data from 1982 participants in the Shandong Yanggu Study of Aging and Dementia, who were aged ≥60 years, free of dementia, and living in the rural communities in western Shandong Province, China. At the baseline (2014) and follow‐up (2018) examinations, sleep parameters were assessed using the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. Global cognitive function was measured using the Mini‐Mental State Examination (MMSE). Dementia was diagnosed following the DSM‐IV criteria, and the NIA‐AA criteria for Alzheimer disease (AD). Data were analyzed using restricted cubic splines, Cox proportional‐hazards models, and general linear models.ResultDuring the mean follow‐up of 3.7 (standard deviation = 0.3) years, dementia was diagnosed in 97 participants (68 with AD). Restricted cubic spline curves showed J‐shaped associations of sleep duration, TIB, and rise time with dementia risk, and a reverse J‐shaped association with mid‐sleep time. When continuous sleep parameters were categorized into tertiles, the multivariable‐adjusted hazard ratio (HR) of incident dementia was 1.69 (95%CI 1.01‐2.83) for baseline sleep duration &gt;8 hours (vs. 7‐8 hours), 2.17 (1.22‐3.87) for bedtime before 9PM (vs. 10PM or later), and 2.00 (1.23‐3.24) for mid‐sleep time before 1AM (vs. 1‐1.5AM). Early bedtime and mid‐sleep time were significantly associated with incident AD (multivariable‐adjusted HR range: 2.25‐2.51; P&lt;0.05). Among individuals who were free of dementia at follow‐up, baseline long TIB, early bedtime and mid‐sleep time, early and late rise time, and prolonged TIB and advanced mid‐sleep time from baseline to follow‐up were associated with greater decline in MMSE score (P&lt;0.05). These associations with cognitive decline were statistically evident mainly among men or participants who were aged &lt;75 years.ConclusionLong TIB and early sleep timing are associated with an increased risk of dementia and AD, and their associations with greater cognitive decline are evident only among young‐old people and men.

0737 Age, menstrual phase, and circadian preference impact sleep in menstruating individuals

Abstract Introduction An eveningness chronotype is generally associated with reduced sleep continuity and quality, as well as social jetlag. Changes in hormones and menstrual phase similarly impact sleep, although research on the chronobiological effects of these changes are equivocal. This study aimed to examine the role of menstrual cycle in daily self-report and actigraphy-assessed sleep in two consecutive menstrual cycles. Methods Participants (n=51; 43% Caucasian), 18-35 years (23.67±4.68) completed actigraphy and daily sleep diaries over two menstrual cycles (m days=51.29). Four menstrual phases were identified via dates of menstrual bleeding and urinary ovulation testing: perimenstrual (±3 days of bleeding), mid-follicular, periovulatory, and mid-luteal. Relationships between menstrual phase and sleep parameters were estimated using multistep hierarchical linear modeling. Subjective and objective measures yielded the following sleep variables: Total Wake Time (TWTsub and TWTobj), Sleep Efficiency (SEsub and SEobj), and mid-sleep point (MSP). Participants completed the Morning-Eveningness Questionnaire (MEQ) at baseline. Results Mean cycle length was 28.61 days±2.69. Age was significantly associated with TWTobj (r=-.32, p &amp;lt;.001); SEobj (r=.34, p &amp;lt;.001), and MSP (r=-.42, p &amp;lt;.001) such that older participants had shorter TWT, higher SE, and earlier MSP. TWTobj was 4-7 minutes lower during the mid-follicular (61.54±3.37) and mid-luteal phases (63.11±3.29) compared to the perimenstrual phase (67.54±3.37; p &amp;lt;.001). SEobj was higher in the mid-luteal phase (82.50±0.79) vs. the perimenstrual phase (80.71±0.82, p =.006). Perimenstrual women reported 8-16 minutes longer awake (TWTsub=52.23±5.01, p &amp;lt;.001) and had 1-3% reduction in SEsub (89.70±0.10, p &amp;lt;.001). MEQ negatively predicted TWTobj (p=.004) and SEobj (p=.003), but did not vary across menstrual phase. In morning-type individuals, TST was significantly higher in the periovulatory (b =1.81, p=.01) and mid-luteal phases (b=2.03, p&amp;lt;.001) compared to the perimenstrual phase. Conclusion With increasing age, women experienced reduced time awake, higher sleep efficiency, and earlier sleep timing. Eveningness predicted greater total wake time and lower sleep efficiency. With menstrual phase considered, disturbed sleep was highest in the perimenstrual phase and women reporting a stronger preference for eveningness reported shorter TST during the perimenstrual phase. These findings highlight the importance of considering the menstrual cycle in the sleep health of menstruating individuals. Support (if any)

Associations between exposure to phthalates, phenols, and parabens with objective and subjective measures of sleep health among Mexican women in midlife: a cross-sectional and retrospective analysis.

Endocrine-disrupting chemicals (EDCs) may impact sleep during the menopausal transition by altering sex hormones. However, these studies are scarce among Latin American women. This investigation utilized cross-sectional and retrospective data from midlife women enrolled in the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) study to examine associations between exposure to EDCs (phthalates, phenols, and parabens) and sleep health measures. For cross-sectional analyses, single spot urine samples were collected between 2017-2019 from a pilot sample of women (N = 91) of midlife age to estimate the urinary concentration of individual phthalates, phenols, and parabens and to calculate the summary concentration of phthalate mixtures. Seven-day nightly sleep duration, midpoint, and fragmentation were obtained from wrist-actigraphy devices and estimated from the actigraphy data using a pruned dynamic programming algorithm. Self-reported poor sleep quality was assessed by one item from the Pittsburgh Sleep Quality Index (PSQI). We examined associations between urinary summary phthalate mixtures, phthalate metabolites, phenol, and paraben analytes with each sleep measure using linear or logistic (to compute odds of poor sleep quality only) regression models adjusted for specific gravity, age, and socioeconomic status. We ran similar regression models for retrospective analyses (N = 74), except that urine exposure biomarker data were collected in 2008 when women were 24-50years old. At the 2017-2019 midlife visit, 38% reported poor sleep quality. Cross-sectionally, EDCs were associated with longer sleep duration, earlier sleep timing, and more fragmented sleep. For example, every 1-unit IQR increase in the phenol triclosan was associated with a 26.3min per night (95% CI: 10.5, 42.2; P < 0.05) longer sleep duration and marginally associated with 0.2 decimal hours (95% CI: -0.4, 0.0; P < 0.10) earlier sleep midpoint; while every 1-unit IQR increase in the phthalate metabolite MEHP was associated with 1.1% higher sleep fragmentation (95% CI: 0.1, 2.1; P < 0.05). Retrospective study results generally mirrored cross-sectional results such that EDCs were linked to longer sleep duration, earlier sleep timing, and more fragmented sleep. EDCs were not significantly associated with odds of self-reported poor sleep quality. Results from cross-sectional and retrospective analyses revealed that higher exposure to EDCs was predictive of longer sleep duration, earlier sleep timing, and more fragmented sleep among midlife women.

Sleep and circadian rhythm profiles in seasonal depression

Sleep and circadian rhythm disruptions are symptoms of, and hypothesized underlying mechanisms in, seasonal depression. Discrepant observational findings and mixed responses to sleep/circadian-based treatments suggest heterogenous sleep and circadian disruptions in seasonal depression, despite these disruptions historically conceptualized as delayed circadian phase and hypersomnia. This study used a data-driven cluster analysis to characterize sleep/circadian profiles in seasonal depression to identify treatment targets for future interventions.Biobehavioral measures of sleep and circadian rhythms were assessed during the winter in individuals with Seasonal Affective Disorder (SAD), subsyndromal-SAD (S-SAD), or nonseasonal, never depressed controls (total sample N = 103). The following variables were used in the cluster analysis: circadian phase (from dim light melatonin onset), midsleep timing, total sleep time, sleep efficiency, regularity of midsleep timing, and nap duration (all from wrist actigraphy). Sleep and circadian variables were compared across clusters and controls.Despite limited sleep/circadian differences between diagnostic groups, there were two reliable (Jaccard Coefficients >0.75) sleep/circadian profiles in SAD/S-SAD individuals: a ‘Disrupted sleep’ cluster, characterized by irregular and fragmented sleep and an ‘Advanced’ cluster, characterized by early sleep and circadian timing and longer total sleep times (>7.5 h). Clusters did not differ by depression severity. Midsleep correlated with DLMO (r = 0.56), irregularity (r = 0.3), and total sleep time (r = −0.27).Sleep and circadian disruptions in seasonal depression are not uniformly characterized by hypersomnia and circadian phase delay. Presence of distinct sleep and circadian subgroups in seasonal depression may predict successful treatment response. Prospective assessment and tailoring of individual sleep and circadian disruptions may reduce treatment failures.

Associations of sleep timing and time in bed with dementia and cognitive decline among Chinese older adults: A cohort study.

The longitudinal associations of sleep timing and time in bed (TIB) with dementia and cognitive decline in older adults are unclear. This population-based cohort study used data from 1982 participants who were aged ≥60 years, free of dementia, and living in rural communities in western Shandong, China. At the baseline (2014) and follow-up (2018) examinations, sleep parameters were assessed using standard questionnaires. Cognitive function was measured using the Mini-Mental State Examination (MMSE). Dementia was diagnosed following the DSM-IV criteria, and the NIA-AA criteria for Alzheimer disease (AD). Data were analyzed using restricted cubic splines, Cox proportional-hazards models, and general linear models. During the mean follow-up of 3.7 years, dementia was diagnosed in 97 participants (68 with AD). Restricted cubic spline curves showed J-shaped associations of sleep duration, TIB, and rise time with dementia risk, and a reverse J-shaped association with mid-sleep time. When sleep parameters were categorized into tertiles, the multivariable-adjusted hazard ratio (HR) of incident dementia was 1.69 (95%CI 1.01-2.83) for baseline sleep duration >8 hours (vs. 7-8 h), 2.17 (1.22-3.87) for bedtime before 9 p.m. (vs. 10 p.m. or later), and 2.00 (1.23-3.24) for mid-sleep time before 1 a.m. (vs. 1-1.5 a.m.). Early bedtime and mid-sleep time were significantly associated with incident AD (HR range: 2.25-2.51; p < 0.05). Among individuals who were free of dementia at follow-up, baseline long TIB, early bedtime and mid-sleep time, early and late rise time, and prolonged TIB and advanced bedtime and mid-sleep time from baseline to follow-up were associated with a greater decline in MMSE score (p < 0.05). These associations with cognitive decline were statistically evident mainly among men or participants who were aged 60-74 years. Long TIB and early sleep timing are associated with an increased risk of dementia, and the associations with greater cognitive decline are evident only among older people aged 60-74 years and men.

Objectively measured physical activity among treatment seeking children and adolescents with severe obesity and normal weight peers.

Treatment seeking children and adolescents with severe obesity often experience barriers to physical activity. Studies objectively measuring physical activity in this group and investigating explanatory factors for physical activity levels could inform clinical practice. This study aimed to compare objectively measured physical activity levels among treatment seeking children and adolescents with severe obesity and normal weight peers, and to investigate explanatory factors for time spent in moderate physical activity and vigorous physical activity among children and adolescents with severe obesity. Children with severe obesity (n=85) were matched 1:1 by age, gender, and the season for accelerometer measurements with normal weight peers (n=85). Children wore accelerometers for seven consecutive days, yielding measures of physical activity, sleep duration and timing. Parents reported on screen time, parental body mass index and participation in organized sports. Children and adolescents with severe obesity spent significantly less time in moderate physical activity (12min, p<0.001) and vigorous physical activity (21min, p<0.001) per day compared to normal weight peers. No difference for time spent in sedentary activity was found between groups. For participants with severe obesity, age ≤12years (p=0.009) and participation in organized sports (p=0.023) were related to more moderate physical activity, while age ≤12years (p=0.038) and early sleep timing (p=0.019) were related to more vigorous physical activity. Children and adolescents with severe obesity were less physically active than their normal weight peers. Factors related to more moderate and vigorous physical activity in children with severe obesity were lower age, participation in organized sports and earlier sleep timing.

Links Between Personality and Sleep Midpoint in Older Adults in the National Social Life, Health, and Aging Project

Chronotype has been linked to poor cognitive outcomes and mortality among older adults. Although previous studies indicate an association between personality and sleep, little is known about associations between personality and chronotype in older adults. We examined the association between personality and objective sleep midpoint (a measure of chronotype) in 463 older adults aged 73.5 ±7.7 from the National Social Life, Health, and Aging Project who completed the Midlife Developmental Inventory Personality scale and three nights of wrist actigraphy, from which we derived participants’ average sleep midpoints. After adjusting for demographics, higher conscientiousness was associated with earlier sleep midpoint (B=-0.53, SE=0.02, p<0.01). Associations for other traits were not significant. Findings link conscientiousness to chronotype and raise the possibility that earlier sleep timing may partially account for associations of conscientiousness with health outcomes. Further studies are needed investigating the role of personality in links of sleep and circadian factors with health.

Reopening after lockdown: the influence of working-from-home and digital device use on sleep, physical activity, and wellbeing following COVID-19 lockdown and reopening.

Study ObjectivesCOVID-19 lockdowns drastically affected sleep, physical activity, and wellbeing. We studied how these behaviors evolved during reopening the possible contributions of continued working from home and smartphone usage.MethodsParticipants (N = 198) were studied through the lockdown and subsequent reopening period, using a wearable sleep/activity tracker, smartphone-delivered ecological momentary assessment (EMA), and passive smartphone usage tracking. Work/study location was obtained through daily EMA ascertainment.ResultsUpon reopening, earlier, shorter sleep and increased physical activity were observed, alongside increased self-rated stress and poorer evening mood ratings. These reopening changes were affected by post-lockdown work arrangements and patterns of smartphone usage. Individuals who returned to work or school in-person tended toward larger shifts to earlier sleep and wake timings. Returning to in-person work/school also correlated with more physical activity. Contrary to expectation, there was no decrease in objectively measured smartphone usage after reopening. A cluster analysis showed that persons with relatively heavier smartphone use prior to bedtime had later sleep timings and lower physical activity.ConclusionsThese observations indicate that the reopening after lockdown was accompanied by earlier sleep timing, increased physical activity, and altered mental wellbeing. Moreover, these changes were affected by work/study arrangements and smartphone usage patterns.

Bangla version of the composite scale of morningness: factor invariance and validity with sleep habits, mood and mental health

ABSTRACT The Composite Scale of Morningness (CSM) is a self-report measure of circadian preference that is related with one’s physical and mental health. This study aimed to explore the psychometric properties of the Bangla version of the CSM and validate it with sleep habits, BRUnel Mood Scale (BRUMS) and Positive Mental Health Scale (PMH-scale). The sample consisted of 1164 (38.8% women) Bangladeshi university students aged between 18 and 27 (M = 21.9, SD = 1.88). Using confirmatory factor analysis, the competing factorial models of the CSM and measurement invariance for sex were tested. The Bangla CSM showed high internal consistency reliability (α = .88) and excellent retest reliability (ICC = .92). The cut-off values for the Bangla CSM were 26 or less for evening-types (lower 10 percentiles) and 46 or more for morning-types (upper 10 percentiles). The Bangla CSM consisted of two components: morningness and morning affect. From eight factorial models, the two-factor bifactor model was found invariant for sex. Higher CSM score (morningness) was significantly related with earlier sleep times, better mood and mental health, which support its validity. The CSM is a valid and psychometrically robust tool for assessing morningness-eveningness in Bangladeshi students.

COVID-19 babies: auto-videosomnography and parent reports of infant sleep, screen time, and parent well-being in 2019 vs 2020

ObjectiveThe COVID-19 pandemic has profoundly impacted families, yet studies on its effects on infants and their parents have thus far been sparse and based mostly on retrospective parent reporting. This study aimed to prospectively evaluate the impact of COVID-19 living conditions on infant and parent sleep, as well as infant screen exposure, parent daytime sleepiness, and parent depression levels, using multi-method assessment. MethodsInfant and parent data collected in 2020 were compared with a matched cohort collected in 2019. The total sample included 1518 US infants aged 1–18 months (M = 8.5, SD = 4.6; 54% boys). Auto-videosomnography metrics were obtained from the 14-day period prior to survey completion (number of analyzed nights: M = 12.11 SD = 2.66 in the 2019 cohort; and M = 11.91 SD = 2.41 in the 2020 cohort). Parents completed online questionnaires regarding their infant's sleep and screen exposure, as well as their own sleep quality, daytime sleepiness, and depression levels. ResultsCompared to 2019, infants in 2020 slept ∼40 min more per night on average, as indicated by auto-videosomnography. Infants additionally had earlier sleep timing, and increased parent-reported sleep-onset latency and nocturnal wakefulness. Infant screen time rose by 18.3 min per day for older infants, but remained stable for younger infants. Parents reported lower daytime sleepiness and higher depression symptomology during 2020, whereas no change was apparent in their sleep quality ratings. ConclusionsRestricted living conditions during COVID-19 in the USA led to increased infant screen exposure and parental depression, but also to increased infant sleep duration and reduced parent sleepiness. Future research is needed to examine the mechanistic pathways through which COVID-19 impacted on infant and parent well-being.

Later sleep timing predicts accelerated summer weight gain among elementary school children: a prospective observational study

Objectives and backgroundSocial demands of the school-year and summer environment may affect children’s sleep patterns and circadian rhythms during these periods. The current study examined differences in children’s sleep and circadian-related behaviors during the school-year and summer and explored the association between sleep and circadian parameters and change in body mass index (BMI) during these time periods.MethodsThis was a prospective observational study with 119 children ages 5 to 8 years with three sequential BMI assessments: early school-year (fall), late school-year (spring), and beginning of the following school-year in Houston, Texas, USA. Sleep midpoint, sleep duration, variability of sleep midpoint, physical activity, and light exposure were estimated using wrist-worn accelerometry during the school-year (fall) and summer. To examine the effect of sleep parameters, physical activity level, and light exposure on change in BMI, growth curve modeling was conducted controlling for age, race, sex, and chronotype.ResultsChildren’s sleep midpoint shifted later by an average of 1.5 h during summer compared to the school-year. After controlling for covariates, later sleep midpoints predicted larger increases in BMI during summer, (γ = .0004, p = .03), but not during the school-year. Sleep duration, sleep midpoint variability, physical activity levels, and sedentary behavior were not associated with change in BMI during the school-year or summer. Females tended to increase their BMI at a faster rate during summer compared to males, γ = .06, p = .049. Greater amounts of outdoor light exposure (γ = −.01, p = .02) predicted smaller increases in school-year BMI.ConclusionsObesity prevention interventions may need to target different behaviors depending on whether children are in or out of school. Promotion of outdoor time during the school-year and earlier sleep times during the summer may be effective obesity prevention strategies during these respective times.

Prenatal Diet in Relation to Sleep Health of Offspring During Adolescence: Evidence From the ELEMENT Study

ObjectivesMaternal diet during gestation has been linked to sex-specific differences in infant sleep; however, the impact on sleep into adolescence is unknown. We sought to examine the relationship between maternal diet patterns and sex-stratified offspring sleep health during adolescence among a Mexico City cohort. MethodsData from 309 mother-adolescent dyads were analyzed. Prenatal diet patterns were formed by principal component analysis derived from a food frequency questionnaire collected over the third trimester. Sleep variables were derived from 7-day actigraphy data from adolescents aged 9–17 years. Linear regression was employed to examine sex-stratified associations between tertiles of the diet patterns with adolescent sleep, adjusting for confounding factors. ResultsThree diet patterns included: the Prudent Diet (PD), high in lean proteins and vegetables; the Transitioning Mexican Diet (TMD) high in Mexican and “Westernized” foods; and the High Meat & Fat Diet (HMFD), high in meats and high-fat dairy products. The mean (SD) offspring age was 15.1 (1.9) years, and 52.4% of the sample was female. The mean (SD) sleep duration was 8.4 (1.4) h/night. Adjusted analyses showed an association between PD adherence and earlier sleep midpoint among female offspring, the offspring of mothers in the highest tertile of PD had a 0.70 h (95% CI: –1.2, –0.20; p = 0.01) earlier sleep midpoint (p, trend = 0.01). Additional associations were detected between TMD prenatal adherence with shorter sleep duration and earlier sleep midpoint among both sexes. For example, female and male offspring of mothers in the highest tertile of TMD had 0.80 h (95% CI: –85.0, –10.6; p = 0.01) (p, trend = 0.0043) and 0.54 h (95% CI: –66.1, 1.3) (p, trend = 0.03) shorter sleep duration, respectively. HMFD prenatal adherence was associated with less fragmented sleep in a non-linear manner among females and was non-linearly associated with an earlier sleep midpoint among males. ConclusionsSex-stratified analyses demonstrated that findings were more robust between multiple diet patterns and shorter sleep, earlier sleep timing, and less fragmented sleep among female offspring, thus indicating that maternal diet during pregnancy may impact female offspring’s sleep health in adolescence. Funding SourcesUS EPA, NIEHS, NHLBI, and the National Institute of Public Health/Ministry of Health of Mexico.

49 Longitudinal Change of Sleep in the Elderly and Its Associations with Health

Abstract Introduction In elderly populations, sleep quality deteriorates and sleep time shifts towards earlier times. These sleep characteristics have been associated with cardiovascular, metabolic and psychiatric disorders, cognitive decline and mortality. Our aims are to examine longitudinal changes of sleep in older adults and to investigate the relationship between sleep variations, general health and mortality. Methods The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age cohort (6,375 participants, recruited in the North of England, between 1983 and 1993) was used. Mixed models were used to investigate individual sleep trajectories (5 waves in 30-year period). Sleep timing and efficiency trajectories were clustered using latent class analysis and analysed against daily habits, health and mortality. Results Older adults have decreased sleep efficiency (~20%) and early sleep time (~30 min) between 40 and 100 years of age. Those in the high sleep efficiency latent class had minimal decrease in their sleep efficiency as they aged. Belonging to the high sleep efficiency latent class was associated with having lower prevalence of hypertension, circulatory problems, arthritis, breathing problems and recurrent depression compared to the low efficiency latent class. Results showed a higher risk of hypertension and metabolic syndrome in the evening-type latent class compared to morning-type individuals. Evening class was associated with traits related to lower health such as reduced sport participation, increased risk of depression and psychoticism personality, late eating, increased smoking and alcohol usage. Survival analysis revealed that individuals in the evening class had 1.15-fold increased risk of all-cause mortality compared to those with morning preferences. Conclusion Ageing is associated with decreased sleep efficiency and early sleep timing. However, there are detectable subgroups of sleep traits that are related to prevalence of different diseases and longevity. Understating these subgroups may pave the way for new treatments for healthy sleeping habits in older population.