Bidirectional associations between sedentary time and sleep duration among 12- to 14-year-old adolescents

Abstract Background The aim of this study was to investigate bidirectional associations between (prolonged) sitting time and sleep duration in 12- to 14-year-old adolescents using a between-subjects and within-subjects analyses approach. Methods Observational data were used from 108 adolescents (53% girls; mean age 12.9 (SD 0.7) years) from six schools in Flanders, Belgium. The Axivity AX3 triaxial accelerometer, worn on the thigh, was used to assess daily total sitting time and daily time spent in sedentary bouts of ≥30 min (as a proxy for prolonged sitting time). The Fitbit Charge 3 was used to assess nightly sleep duration. Both monitors were worn on schooldays only (ranging from 4 to 5 days). Linear mixed models were conducted to analyse the associations, resulting in four models. In each model, the independent variable (sleep duration, sitting time or prolonged sitting time) was included as within- as well as between-subjects factor. Results Within-subjects analyses showed that when the adolescents sat more and when the adolescents spent more time sitting in bouts of ≥30 min than they usually did on a given day, they slept less during the following night (p = 0.01 and p = 0.05 (borderline significant), respectively). These associations were not significant in the other direction. Between-subjects analyses showed that adolescents who slept more on average, spent less time sitting (p = 0.006) and less time sitting in bouts of ≥30 min (p = 0.004) compared with adolescents who slept less on average. Conversely, adolescents who spent more time sitting on average and adolescents who spent more time sitting in bouts of ≥30 min on average, slept less (p = 0.02 and p = 0.003, respectively). Conclusions Based on the between-subjects analyses, interventions focusing on reducing or regularly breaking up sitting time could improve adolescents’ sleep duration on a population level, and vice versa. However, the within-subjects association was only found in one direction and suggests that to sleep sufficiently during the night, adolescents might limit and regularly break up their sitting time the preceding day. Trial registration Data have been used from our trial registered at ClinicalTrials.gov (NCT04327414; registered on March 11, 2020).

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Simple intermittent resistance activity mitigates the detrimental effect of prolonged unbroken sitting on arterial function in overweight and obese adults

Journal of Applied Physiology ◽

10.1152/japplphysiol.00544.2018 ◽

2018 ◽

Vol 125 (6) ◽

pp. 1787-1794 ◽

Cited By ~ 12

Author(s):

Rachel E. Climie ◽

Michael J. Wheeler ◽

Megan Grace ◽

Elisabeth A. Lambert ◽

Neale Cohen ◽

...

Keyword(s):

Cardiovascular Disease ◽

Shear Rate ◽

Adhesion Molecule ◽

Femoral Artery ◽

Sitting Time ◽

Cvd Risk ◽

Obese Adults ◽

Arterial Function ◽

Endothelin 1 ◽

Prolonged Sitting

Prolonged sitting contributes to cardiovascular disease (CVD) risk. The underlying mechanisms are unknown but may include changes in arterial function and vasoactive mediators. We examined the effects of prolonged unbroken sitting, relative to regular active interruptions to sitting time, on arterial function in adults at increased CVD risk. In a randomized crossover trial, 19 sedentary overweight/obese adults (mean ± SD age 57 ± 12 yr) completed 2 laboratory-based conditions: 5 h uninterrupted sitting (SIT) and 5 h sitting interrupted every 30 min by 3 min of simple resistance activities (SRA). Femoral artery function [flow-mediated dilation (FMD)], blood flow, and shear rate were measured at 0 h, 30 min, 1 h, 2 h, and 5 h. Brachial FMD was assessed at 0 and 5 h. Plasma was collected hourly for measurement of endothelin-1 (ET-1), nitrates/nitrites, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). There was a significant decline in femoral artery FMD, averaged over 5 h in the SIT condition, relative to SRA ( P < 0.001). Plasma ET-1 total area under the curve over 5 h increased in the SIT condition compared with SRA ( P = 0.006). There was no significant difference between conditions in femoral or brachial shear rate, brachial FMD, nitrates/nitrites, VCAM-1, or ICAM-1 ( P > 0.05 for all). Five hours of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating ET-1 in overweight/obese adults. There is the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting. NEW & NOTEWORTHY This is the first study to examine the effect of prolonged sitting on arterial function in adults at increased cardiovascular disease risk. We have shown that 5 h of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating endothelin-1 in overweight/obese adults. There is now the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting.

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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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Behavioral Correlates of Depression Among Adults with Visual Impairments

Journal of Visual Impairment & Blindness ◽

10.1177/0145482x211046696 ◽

2021 ◽

pp. 0145482X2110466

Author(s):

Justin A. Haegele ◽

Xihe Zhu ◽

Sean Healy

Keyword(s):

Physical Activity ◽

Visual Impairment ◽

Sleep Duration ◽

Visual Impairments ◽

The United States ◽

Sitting Time ◽

Hierarchical Regression ◽

Regression Analyses ◽

The Impact ◽

Negative Predictor

Introduction: This study sought to examine: (a) the associations between physical activity, sedentary time, and sleep duration, as discrete behaviors, with depression among adults with visual impairments; and (b) the impact of meeting none, one, two, or three of the guidelines for these behaviors on depression among adults with visual impairments. Materials: One hundred eighty-two ( Mage = 44.8) adults with visual impairments, recruited via email through two visual impairment organizations in the United States, completed the International Physical Activity Questionnaire–Short Form, a sleep duration question, the Major Depression Inventory, and a demographic questionnaire. Based on results from the questionnaires, dichotomous variables for meeting or not meeting physical activity, sleep, and sitting guidelines were created. Data were analyzed using three components: a descriptive analysis, Pearson product-moment correlation analyses, and hierarchical regression analyses. Results: Overall, 14.8% of participants were categorized as having some degree of depression. Meeting the sleep guideline was a significant negative predictor of depression scores in the hierarchical regression analyses. The number of guidelines met was a negative predictor for depression score controlling for other variables. Discussion: Adequate sleep, as well as meeting all three guidelines synergistically, was meaningful in influencing depression among this population. The current study’s results should prompt the continued examination of health-behaviors among adults with visual impairment using a more holistic 24-hour activity cycle framework. Implications for practitioners: This study supports the utilization of multi-behavioral interventions to reduce the risk of depression by enhancing physical activity and sleep, while reducing sitting time, among this population.

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The Effects of Superficial Heating before 1-MHz Ultrasound on Tissue Temperature

Journal of Sport Rehabilitation ◽

10.1123/jsr.12.2.95 ◽

2003 ◽

Vol 12 (2) ◽

pp. 95-103 ◽

Cited By ~ 3

Author(s):

William R. Holcomb ◽

Chris Blank

Keyword(s):

Athletic Training ◽

Repeated Measures ◽

Outcome Measure ◽

Tissue Temperature ◽

Temperature Elevation ◽

Main Outcome Measure ◽

Cooling Period ◽

Dependent Variables ◽

Within Subjects ◽

Independent Variable

Context:Ultrasound significantly raises tissue temperature, but the time of temperature elevation is short.Objective:To assess the effectiveness of superficial preheating on temperature elevation and decline when using ultrasound.Design:Within-subjects design to test the independent variable, treatment condition; repeated-measures ANOVAs to analyze the dependent variables, temperature elevation and decline.Setting:Athletic training laboratory.Intervention:Temperature at a depth of 3.75 cm was measured during ultrasound after superficial heating and with ultrasound alone.Subjects:10 healthy men.Main Outcome Measure:Temperature was recorded every 30 s during 15 min of ultrasound and for 15 min afterward.Results:Temperature elevation with ultrasound was significantly greater with preheating (4.0 ± 0.21 °C) than with ultrasound alone (3.0 ± 0.22 °C). Temperature decline was not significantly different between preheating and ultrasound alone.Conclusions:Superficial preheating significantly increases temperature elevation but has no effect on temperature decline during a 15-min cooling period.

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Addressing physical inactivity in Omani adults: perceptions of public health managers

Public Health Nutrition ◽

10.1017/s1368980012005678 ◽

2013 ◽

Vol 17 (3) ◽

pp. 674-681 ◽

Cited By ~ 13

Author(s):

Ruth M Mabry ◽

Zakiya Q Al-Busaidi ◽

Marina M Reeves ◽

Neville Owen ◽

Elizabeth G Eakin

Keyword(s):

Public Health ◽

Physical Inactivity ◽

Ecological Model ◽

Adult Population ◽

Arabian Gulf ◽

Sitting Time ◽

Structured Interviews ◽

Prolonged Sitting ◽

Culturally Sensitive Interventions ◽

Health Managers

AbstractObjectiveTo explore barriers and solutions to addressing physical inactivity and prolonged sitting in the adult population of Oman.DesignQualitative study involving semi-structured interviews that took place from October 2011 to January 2012. Participants were recruited through purposive sampling. Data collection and analysis was an iterative process; later interviews explored emerging themes. Interviews were audio-recorded and transcribed and continued until data saturation; this occurred by the tenth interviewee. Thematic content analysis was carried out, guided by an ecological model of health behaviour.SettingMuscat, Oman.SubjectsTen mid-level public health managers.ResultsBarriers for physical inactivity were grouped around four themes: (i) intrapersonal (lack of motivation, awareness and time); (ii) social (norms restricting women's participation in outdoor activity, low value of physical activity); (iii) environment (lack of places to be active, weather); and (iv) policy (ineffective health communication, limited resources). Solutions focused on culturally sensitive interventions at the environment (building sidewalks and exercise facilities) and policy levels (strengthening existing interventions and coordinating actions with relevant sectors). Participants’ responses regarding sitting time were similar to, but much more limited than those related to physical inactivity, except for community participation and voluntarism, which were given greater emphasis as possible solutions to reduce sitting time.ConclusionsGiven the increasing prevalence of chronic disease in Oman and the Arabian Gulf, urgent action is required to implement gender-relevant public health policies and programmes to address physical inactivity, a key modifiable risk factor. Additionally, research on the determinants of physical inactivity and prolonged sitting time is required to guide policy makers.

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Longitudinal Changes in Sitting Patterns, Physical Activity, and Health Outcomes in Adolescents

Children ◽

10.3390/children6010002 ◽

2018 ◽

Vol 6 (1) ◽

pp. 2 ◽

Cited By ~ 5

Author(s):

Ana Contardo Ayala ◽

Jo Salmon ◽

David Dunstan ◽

Lauren Arundell ◽

Kate Parker ◽

...

Keyword(s):

Physical Activity ◽

Vigorous Physical Activity ◽

Activity Patterns ◽

Sitting Time ◽

Linear Regression Models ◽

Anthropometric Measures ◽

Prolonged Sitting ◽

Intensity Physical Activity ◽

Changes Over Time

This study examined two-year changes in patterns of activity and associations with body mass index (BMI) and waist circumference (WC) among adolescents. Inclinometers (activPAL) assessed sitting, sitting bouts, standing, stepping, and breaks from sitting. ActiGraph-accelerometers assessed sedentary time (SED), light-intensity physical activity (LIPA, stratified as low- and high-LIPA), and moderate-to-vigorous physical activity (MVPA). Anthropometric measures were objectively assessed at baseline and self-reported at follow-up. Data from 324 and 67 participants were obtained at baseline and follow-up, respectively. Multilevel mixed-effects linear regression models examined changes over time, and associations between baseline values and BMI and WC at follow-up. There were significant increases in BMI (0.6 kg/m2) and durations of prolonged sitting (26.4 min/day) and SED (52 min/day), and significant decreases in stepping (−19 min/day), LIPA (−33 min/day), low-LIPA (−26 min/day), high-LIPA (−6.3 min/day), MVPA (−19 min/day), and the number of breaks/day (−8). High baseline sitting time was associated (p = 0.086) with higher BMI at follow-up. There were no significant associations between baseline sitting, prolonged sitting, LIPA, or MVPA with WC. Although changes in daily activity patterns were not in a favourable direction, there were no clear associations with BMI or WC. Research with larger sample sizes and more time points is needed.

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Student mood and responses to standing desks in the college classroom

American Journal of Health Studies ◽

10.47779/ajhs.2020.257 ◽

2021 ◽

Vol 35 (4) ◽

Author(s):

Ryan M. Green ◽

Myia L. Graves ◽

Carrie M. Edwards ◽

Edward P. Hebert ◽

Daniel B. Hollander

Keyword(s):

Physical Activity ◽

Metabolic Syndrome ◽

Undergraduate Students ◽

Sitting Time ◽

College Classrooms ◽

Class Meetings ◽

Students First ◽

Negative Effect ◽

Within Subjects

Physical activity enhances physical health, reduces disease, and resists metabolic syndrome and obesity, while sitting for extended periods of time has a negative effect on long term health outcomes. Thus, reducing sitting time has been identified as a health-enhancing goal. The purpose of this study was to explore perceptions and responses of college students to sitting versus standing in class. Five standing desks were placed in a classroom of traditional sitting desks. In a counterbalanced, within subjects design, 88 undergraduate students (age M=21.64, SD=6.55 years) participated in the study. Some participating students first stood at a desk for three consecutive class meetings and then sat for three classes while others sat for three consecutive classes and then stood for three. Surveys were administered at the beginning and end of each class and at the end of six consecutive class sessions. Results indicated that mood was signifi- cantly higher on standing than sitting days, the majority of participants had a favorable perception of the standing-in-class experience, and would use standing stations if the option was available. This study is one of few to examine the viability and response to adding standing desks in college classrooms, and indicates standing desks may be perceived favorably and could be utilized to reduce sitting time.

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Abstract MP38: Longitudinal Population-Level Changes In Resting Heart Rate During The COVID-19 Pandemic: Impact Of Changes In Sleep, Circadian, And Physical Activity Variables

Circulation ◽

10.1161/circ.143.suppl_1.mp38 ◽

2021 ◽

Vol 143 (Suppl_1) ◽

Author(s):

Naghmeh Rezaei ◽

Michael A Grandner

Keyword(s):

New York ◽

Heart Rate ◽

Los Angeles ◽

Health Behaviors ◽

San Francisco ◽

Sleep Duration ◽

Age Groups ◽

Population Level ◽

Sleep Stages ◽

Resting Heart Rate

Introduction: Population-level objective estimates of changes in health metrics over the course of the COVID-19 pandemic are sparse. This study evaluated change in resting heart rate (RHR) determined by optical plethysmography and relationships to changes in other lifestyle health behaviors (sleep and activity). Methods: Data were obtained from N=197,988 Fitbit users who wore their heart-rate enabled Fitbit device to sleep and had detected sleep stages at least 10 days in the month of January, the baseline period; and synced their devices at least once in the last 10 days of April. In addition, potential participants needed to reside in one of 6 target cities: Chicago, Illinois; Houston, Texas; Los Angeles, California; San Francisco, California; New York City, New York; and Miami, Florida. Users who met these criteria were randomly selected. Daily RHR, sleep duration (minutes), sleep duration variability (standard deviation), bedtime, step count, and active minutes were estimated by the device. Differences between January (before the pandemic) and April (peak of stay-at-home orders) was computed. Correlations between change in RHR and change in other variables were evaluated, stratified by age and sex. Results: For all age groups, in both men and women, mean RHR declined from January to April by about 1bpm, with the highest reductions in the youngest adults (all p<1x10 -100 ). In general, across both genders and all age groups, reductions in RHR were correlated with greater sleep duration, delaying bedtime, reduced sleep variability, and more active minutes. Steps were also associated in younger (but not older) adults. Results for ages 18-29 and >=65 are displayed in the Table. Discussion: During the COVID-19 pandemic, RHR decreased robustly but very slightly. Reductions in RHR were correlated with improvements in other health behaviors (sleep and activity). Causal relationships could not be evaluated, but future studies may explore whether even small changes in health behaviors can measurably impact population RHR.

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Does Interrupting Prolonged Sitting With 10- or 20-Min Standing Attenuate Postprandial Glycemia and Blood Pressure in Middle-Aged and Older Adults With Type 2 Diabetes?

Journal of Aging and Physical Activity ◽

10.1123/japa.2020-0418 ◽

2020 ◽

pp. 1-8

Author(s):

Yuri A. Freire ◽

Carlos A. Silva ◽

Geovani A. D. Macêdo ◽

Rodrigo A. V. Browne ◽

Bruno M. de Oliveira ◽

...

Keyword(s):

Blood Pressure ◽

Type 2 Diabetes ◽

Older Adults ◽

Area Under The Curve ◽

Acute Effect ◽

Sitting Time ◽

Middle Aged ◽

Postprandial Glycemia ◽

Prolonged Sitting

We carried out three types of 2-hr experimental sessions with middle-aged and older adults with Type 2 diabetes in order to examine the acute effect of interrupting prolonged sitting with varying periods of standing on postprandial glycemia and blood pressure (BP): (a) prolonged sitting after breakfast; (b) standing for 10 min, 30 min after breakfast; and (c) standing for 20 min, 30 min after breakfast. Glucose and BP were assessed before and after breakfast. A generalized linear model revealed no significant differences for the incremental area under the curve of glucose between standing for 10 min, 30 min after breakfast, versus prolonged sitting after breakfast (β = –4.5 mg/dl/2 hr, 95% CI [–17.3, 8.4]) and standing for 20 min, 30 min after breakfast, versus prolonged sitting after breakfast (β = 0.9 mg/dl/2 hr, 95% CI [–11.9, 13.7]). There was no difference in area under the curve of systolic and diastolic BP among the sessions. Interrupting prolonged sitting time with 10 or 20 min of standing 30 min after breakfast does not attenuate postprandial glycemia or BP in middle-aged and older adults with Type 2 diabetes.

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190 Changing national trends in sleep and related features among Korean adults between 2009 and 2018

SLEEP ◽

10.1093/sleep/zsab072.189 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A76-A77

Author(s):

Jee-Eun Yoon ◽

Daeyoung Kim ◽

Kwang Ik Yang ◽

Min Kyung Chu ◽

Chang-Ho Yun

Keyword(s):

Phase I ◽

Sleep Duration ◽

Adult Population ◽

Population Level ◽

Nationwide Survey ◽

Study Phase ◽

Poor Sleep ◽

Cross Sectional ◽

Targeted Interventions ◽

Korean Adults

Abstract Introduction Sleep patterns have been linked to various heath disease. Evaluating population-level trend of sleep could provide a comprehensive population health-forecasting model that has the potential to inform targeted interventions. Therefore, we aimed to examine the cross-sectional differences in sleep characteristics among Korean adults during a 9-year period of 2009-2018. Methods The data in this study were derived from two nationwide survey regarding sleep and headache in the representative sample of Korean adult population, namely the Korean Sleep Headache Study phase I (2009) and II (2018). The survey was conducted through door-to-door visit and face-to-face interview by using structured questionnaires. Total of 2,836 participants from Phase I (47.9±16.4 years old; female, 50.2%) and 2,501 participants (47.9±16.4 years old; female, 50.3%) from Phase II gave informed consents and completed the survey. For this study, we excluded those who worked as shift workers and missing data. From the MCTQ, we collected participants’ sleep schedule during workdays and free days over the past four weeks. Average sleep duration was a weighted mean of sleep duration on workdays and free days. Poor sleep quality was defined as PSQI >5. Excessive daytime sleepiness and Depression are performed with ESS and PHQ-9, respectively. Results During the 9 years, average sleep duration decreased by 21 minutes, especially more reduction on free days (workday: 7:17±1:58 vs. 7:06±1:06, p <0.001; free days 8:04±2:32 vs. 7:49±1:23, p <0.001). People go to sleep and wake up earlier on workday (workday 23:39±1:50 vs. 23:25±1:30, p <0.001; free days 23:51±2:11 vs. 23:25±2:11, p <0.001), whereas they go to bed earlier and wake up later on free days compared to past (workday 6:52±1:36 vs. 6:37±1:11, p <0.001; 7:42±2:04 vs. 7:49±1:42 p =0.023). Social jetlag was increased by 5 minutes (0:46±1:35 vs. 0:51±0:52, p =0.028). There was the difference of age on the habitual sleep-wake rhythm and sleep related symptoms. Also, short or long sleep duration was associated with a significant increase in each health outcomes. Conclusion Decreased sleep duration seems to be on the rise in the general adult population, which lead to a poor health status. Interventions to promote adequate sleep is urgently needed. Support (if any):

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