0011 Modeling Endogenous and Exogenous Sources of Sleep Timing Variability

Abstract Introduction The relationship between sleep duration and loneliness among healthy older adults is not fully understood. Shorter sleep duration and increased variability of sleep timing (sleep onset and wake time) have recently been shown to have adverse health outcomes in younger adults. While physiological stressors associated with loneliness are likely distinct, we hypothesise that older adults who identify as lonely have reduced sleep duration and increased variability of sleep timing. Methods Older individuals (N=60) without significant co-morbidities were recruited via convenience sampling. Participants completed the de Jong Giervield Loneliness Scale and wore an actigraph for up to 2 weeks. Sleep metrics from actigraphy (sleep onset and wake times, and SD) were determined by algorithm assisted human scoring. Results Valid data was retrieved from N=37 participants (age 83±6.8 years [mean±SD]). There were no significant differences in demographics between those in the lonely (N=19) and not lonely (N=18) groupings. There was substantial heterogeneity in individual participant’s sleep metrics, both within and between groupings. The average sleep onset time was similar between groups, however lonely participants typically woke earlier resulting in slightly shorter sleep duration. Variability in sleep onset and wake times was reduced in lonely participants. Discussion While shorter sleep duration was expected, we did not anticipate the reduction in sleep timing variability amongst those defined as lonely; more regular sleep periods have previously been associated with better outcomes. We did not see statistically significant differences between our groups, possibly due to sample size limitations, however, the unexpected trend warrants further investigation.

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Rapid changes in overnight blood pressure after transitioning to early-morning shiftwork

SLEEP ◽

10.1093/sleep/zsab203 ◽

2021 ◽

Author(s):

Andrew W McHill ◽

Josie Velasco ◽

Todd Bodner ◽

Steven A Shea ◽

Ryan Olson

Keyword(s):

Blood Pressure ◽

Disease Risk ◽

Cardiovascular Disease Risk ◽

Early Morning ◽

Warning Sign ◽

Sleep Timing ◽

Timing Variability ◽

Significant Difference ◽

Blood Pressure Dipping ◽

Newly Hired

Abstract Risk for adverse cardiovascular events increases when blood pressure does not decrease at night (“non-dipping”, <10% decrease from daytime blood pressure). Shiftwork alters relationships between behaviors and endogenous circadian rhythms (i.e., circadian disruption along with variable sleep timing), and chronic shiftwork increases cardiovascular disease risk. To determine whether transitioning into shiftwork changes the overnight blood pressure dipping pattern, we leveraged a natural experiment that occurs when newly-hired bus operators transition from a daytime training schedule into an early-morning shiftwork or daywork schedule. Twenty participants were studied in a 90-day protocol upon new employment and underwent cardio-metabolic health assessments, including ambulatory blood pressure monitoring, and weekly sleep-wake diaries. Measurements were repeated after ~30 and 90 days after transitioning to a day or an early-morning shiftwork schedule. Newly-hired shiftworkers displayed dramatic changes in overnight blood pressure, with 62% converting from a healthy dipping blood pressure to the non-dipping pattern, resulting in 93% of shiftworkers displaying a non-dipping phenotype at 90-days. In contrast, 50% of dayworkers had a non-dipping profile at baseline and this decreased to 0% at 90-days, a significant difference from shiftworkers (p=0.001). At 90-days, overnight blood pressure dipping was ~7% less in shiftworkers than dayworkers (-6.3% [95%CI -3.7 to -8.8%] vs -13.1% [-10.3 to -15.9%]: p<0.01), with changes in dipping associated with changes in sleep timing variability (r 2=0.28, p=0.03). The observed changes in overnight blood pressure dipping in newly-hired early-morning shiftworkers, which were associated with sleep timing variability, may be an early warning sign of increased cardiovascular risk among shiftworkers.

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An exploratory study of associations between sleep timing variability and cardiometabolic health in middle-aged adults with type 2 diabetes mellitus

Chronobiology International ◽

10.1080/07420528.2021.2005083 ◽

2022 ◽

pp. 1-10

Author(s):

Rachael M. Kelly ◽

Ultan Healy ◽

Seamus Sreenan ◽

John McDermott ◽

Andrew N. Coogan

Keyword(s):

Diabetes Mellitus ◽

Type 2 Diabetes ◽

Type 2 Diabetes Mellitus ◽

Exploratory Study ◽

Cardiometabolic Health ◽

Middle Aged ◽

Sleep Timing ◽

Timing Variability ◽

Middle Aged Adults

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Effects of Quarantine Due to the COVID-19 on Sleep Duration and Quality in Algerians

Acta Facultatis Educationis Physicae Universitatis Comenianae ◽

10.2478/afepuc-2020-0015 ◽

2020 ◽

Vol 60 (2) ◽

pp. 182-193

Author(s):

Kacem Abdelhadi ◽

Houar Abdelatif ◽

Zerf Mohamed ◽

Bengoua Ali

Keyword(s):

Statistical Analysis ◽

Sleep Quality ◽

Sleep Duration ◽

Online Survey ◽

Public Awareness ◽

Italian Version ◽

Sleep Timing ◽

Algerian Population ◽

Significant Change ◽

The Impact

SummaryThis study tests the impact of COVID-19 on sleep of Algerian population before and during the COVID-19 quarantine by an estimated online survey, adapted from the PSQI Italian version. Including 1210 participants (age between 18-60 years old). The statistical analysis was carried out using SPSS version 22.0 software. Our results showed a significant change in sleeping quality during quarantine, the sleep timing markedly changed, we also noticed additional use of sleeping medications. Algerian scientists recommend to build public awareness and to provide necessary information regarding Algerian sleep quality, especially for Algerian adults.

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Meal and Sleep Timing before and during the COVID-19 Pandemic: A Cross-Sectional Anonymous Survey Study from Sweden

Clocks & Sleep ◽

10.3390/clockssleep3020015 ◽

2021 ◽

Vol 3 (2) ◽

pp. 251-258

Author(s):

Christian Benedict ◽

Luiz Eduardo Mateus Brandão ◽

Ilona Merikanto ◽

Markku Partinen ◽

Bjørn Bjorvatn ◽

...

Keyword(s):

Sample Size ◽

Metabolic Health ◽

Survey Study ◽

Cross Sectional ◽

Daily Routines ◽

Sleep Timing ◽

Social Jetlag ◽

Meal Timing ◽

At Home

The COVID-19 pandemic and related restrictions, such as stay-at-home-orders, have significantly altered daily routines and lifestyles. Given their importance for metabolic health, we herein compared sleep and meal timing parameters during vs. before the COVID-19 pandemic based on subjective recall, in an anonymous Swedish survey. Among 191 adults (mean age: 47 years; 77.5% females), we show that social jetlag, i.e., the mismatch in sleep midpoint between work and free days, was reduced by about 17 min during the pandemic compared with the pre-pandemic state (p < 0.001). Concomitantly, respondents’ sleep midpoint was shifted toward morning hours during workdays (p < 0.001). A later daily eating midpoint accompanied the shift in sleep timing (p = 0.001). This effect was mainly driven by a later scheduled first meal (p < 0.001). No difference in the timing of the day’s last meal was found (p = 0.814). Although our survey was limited in terms of sample size and by being cross-sectional, our results suggest that the delay in sleep timing due to the COVID-19 pandemic was accompanied by a corresponding shift in the timing of early but not late meals.

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

Age and Ageing ◽

10.1093/ageing/afab030.10 ◽

2021 ◽

Vol 50 (Supplement_1) ◽

pp. i12-i42

Author(s):

A Didikoglu ◽

A Maharani ◽

A Payton ◽

M M Canal ◽

N Pendleton

Keyword(s):

Older Adults ◽

Latent Class ◽

Sport Participation ◽

Sleep Time ◽

Sleep Efficiency ◽

Longitudinal Change ◽

Sleep Timing ◽

Increased Risk ◽

Health And Mortality ◽

Evening Class

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.

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542 Objective Sleep Duration, Sleep Timing and Completion of In Vitro Fertilization Cycles; a Prospective Cohort Study

SLEEP ◽

10.1093/sleep/zsab072.540 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A214-A214

Author(s):

Chawanont Pimolsri ◽

Xiru Lyu ◽

Cathy Goldstein ◽

Chelsea Fortin ◽

Sunni Mumford ◽

...

Keyword(s):

Embryo Transfer ◽

Sleep Duration ◽

Medical Center ◽

Working Women ◽

Vitro Fertilization ◽

Circadian Misalignment ◽

Logistic Regression Models ◽

Sleep Timing

Abstract Introduction Sleep duration and circadian misalignment have been linked to fertility and fecundability. However, sleep in women undergoing IVF has rarely been examined. This study investigated the role of sleep duration and timing with completion of an IVF cycle. Methods Prospective study of women undergoing IVF at a tertiary medical center between 2015 and 2017. Sleep was assessed by wrist-worn actigraphy 1–2 weeks prior to the initiation of their IVF cycle. Reproductive profile, IVF cycle details, demographic and health information were obtained from medical charts. Sleep duration, midpoint and bedtime were examined in relation to IVF cycle completion using logistic regression models, adjusted for age and anti-Müllerian hormone levels. A sub-analysis excluded women who worked non-day shifts to control for circadian misalignment. Results A total of 48 women were studied. Median age was 33y (range 25–42), with 29% of women older than 35 years. Ten women had an IVF cycle cancellation prior to embryo transfer. These women had shorter sleep duration, more nocturnal awakenings, lower sleep efficiency, and later sleep timing in comparison to those who completed their cycle. Twenty-minute increases in sleep duration were associated with lower odds of an uncompleted IVF cycle (OR = 0.88; 95% CI 0.78, 1.00). Women with later sleep midpoints and later bedtime had higher odds of an uncompleted cycle relative to those with earlier midpoints and earlier bedtime; OR=1.24; 95% CI 1.09, 1.40 and OR=1.33; 95% CI 1.17, 1.53 respectively, per 20-minute increments. These results were independent of age, levels of anti-Müllerian hormone, or sleep duration, and remained unchanged after exclusion of shift-working women. Conclusion This study demonstrated the influence of sleep duration and sleep timing on the odds of an uncompleted IVF cycle prior to embryo transfer. Sleep is a modifiable behavior that may contribute to IVF cycle success. Support (if any):

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Adverse impact of polyphasic sleep patterns in humans: Report of the National Sleep Foundation sleep timing and variability consensus panel

Sleep Health ◽

10.1016/j.sleh.2021.02.009 ◽

2021 ◽

Author(s):

Matthew D. Weaver ◽

Tracey L. Sletten ◽

Russell G. Foster ◽

David Gozal ◽

Elizabeth B. Klerman ◽

...

Keyword(s):

Adverse Impact ◽

Sleep Patterns ◽

Consensus Panel ◽

Sleep Timing

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214 Longitudinal Changes in Sleep Duration, Timing, Variability, and Stages during the COVID-19 Pandemic: Large-Scale Fitbit Data

SLEEP ◽

10.1093/sleep/zsab072.213 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A86-A86

Author(s):

Michael Grandner ◽

Naghmeh Rezaei

Keyword(s):

New York ◽

Los Angeles ◽

San Francisco ◽

Sleep Duration ◽

Large Scale ◽

Age Groups ◽

Population Level ◽

Sleep Stages ◽

Longitudinal Changes ◽

Timing Variability

Abstract Introduction The COVID-19 pandemic has resulted in societal-level changes to sleep and other behavioral patterns. Objective, longitudinal data would allow for a greater understanding of sleep-related changes at the population level. Methods N= 163,524 deidentified active Fitbit users from 6 major US cities contributed data, representing areas particularly hard-hit by the pandemic (Chicago, Houston, Los Angeles, New York, San Francisco, and Miami). Sleep variables extracted include nightly and weekly mean sleep duration and bedtime, variability (standard deviation) of sleep duration and bedtime, and estimated arousals and sleep stages. Deviation from similar timeframes in 2019 were examined. All analyses were performed in Python. Results These data detail how sleep duration and timing changed longitudinally, stratified by age group and gender, relative to previous years’ data. Overall, 2020 represented a significant departure for all age groups and both men and women (P<0.00001). Mean sleep duration increased in nearly all groups (P<0.00001) by 5-11 minutes, compared to a mean decrease of 5-8 minutes seen over the same period in 2019. Categorically, sleep duration increased for some and decreased for others, but more extended than restricted. Sleep phase shifted later for nearly all groups (p<0.00001). Categorically, bedtime was delayed for some and advanced for others, though more delayed than advanced. Duration and bedtime variability decreased, owing largely to decreased weekday-weekend differences. WASO increased, REM% increased, and Deep% decreased. Additional analyses show stratified, longitudinal changes to sleep duration and timing mean and variability distributions by month, as well as effect sizes and correlations to other outcomes. Conclusion The pandemic was associated with increased sleep duration on average, in contrast to 2019 when sleep decreased. The increase was most profound among younger adults, especially women. The youngest adults also experienced the greatest bedtime delay, in line with extensive school-start-times and chronotype data. When given the opportunity, the difference between weekdays and weekends became smaller, with occupational implications. Sleep staging data showed that slightly extending sleep minimally impacted deep sleep but resulted in a proportional increase in REM. Wakefulness during the night also increased, suggesting increased arousal despite greater sleep duration. Support (if any) This research was supported by Fitbit, Inc.

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Later Meal and Sleep Timing Predicts Higher Percent Body Fat

Nutrients ◽

10.3390/nu13010073 ◽

2020 ◽

Vol 13 (1) ◽

pp. 73

Author(s):

Elizabeth A. Thomas ◽

Adnin Zaman ◽

Marc-Andre Cornier ◽

Victoria A. Catenacci ◽

Emma J. Tussey ◽

...

Keyword(s):

Body Fat ◽

Overweight And Obesity ◽

Percent Body Fat ◽

P Value ◽

Activity Monitors ◽

Food Records ◽

Sleep Timing ◽

Meal Timing ◽

Increased Risk ◽

Unit Increase

Accumulating evidence suggests that later timing of energy intake (EI) is associated with increased risk of obesity. In this study, 83 individuals with overweight and obesity underwent assessment of a 7-day period of data collection, including measures of body weight and body composition (DXA) and 24-h measures of EI (photographic food records), sleep (actigraphy), and physical activity (PA, activity monitors) for 7 days. Relationships between body mass index (BMI) and percent body fat (DXA) with meal timing, sleep, and PA were examined. For every 1 h later start of eating, there was a 1.25 (95% CI: 0.60, 1.91) unit increase in percent body fat (False Discovery Rate (FDR) adjusted p value = 0.010). For every 1 h later midpoint of the eating window, there was a 1.35 (95% CI: 0.51, 2.19) unit increase in percent body fat (FDR p value = 0.029). For every 1 h increase in the end of the sleep period, there was a 1.64 (95% CI: 0.56, 2.72) unit increase in percent body fat (FDR p value = 0.044). Later meal and sleep timing were also associated with lower PA levels. In summary, later timing of EI and sleep are associated with higher body fat and lower levels of PA in people with overweight and obesity.

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