Health outcomes associated with reallocations of time between sleep, sedentary behaviour, and physical activity: a systematic scoping review of isotemporal substitution studies

24-H movement behaviours research in Chinese population: A scoping review

Background

Numerous studies examining 24-h movement behaviours have been exponentially published globally. However, no comprehensive reviews summarized and synthesized the evidence on the Chinese population. This review aimed to map the most recent research state and fill the gaps related to 24-h movement behaviours in the Chinese population.

Methods

Five electronic databases (Web of Science, PubMed, Scopus, EBSCOhost, and CNKI (Chinese database)) were searched from their inceptions through October 2023. Quantitative studies published in English and/or Chinese were included if they were related to 24-h movement behaviours in the Chinese population.

Results

From 9431 documents screened, 53 met the inclusion criteria. All the included studies were published between 2019 and 2023, showing a notable increasing trend over the years. Most studies used cross-sectional designs (96.2 %) and self-reported measures (56.6 %). Nearly all the studies targeted general healthy population (96.2 %), especially children and adolescents (64.2 %). The main three research topics observed were health outcomes (81.1 %), prevalence (66.0 %), and correlates (15.1 %) of 24-h movement behaviours.

Conclusion

24-h movement behaviours in the Chinese population has been an increasingly important research topic in the literature, with predominant focus on children and adolescents (study population), self-report measure (measurement), cross-sectional design (study design), guidelines adherence (study topic), and health outcomes examination (study topic). These findings delineate a research landscape in the Chinese population, and highlight the research gaps needed to be addressed. Future studies are suggested to target these research gaps, expanding evidence base for the Chinese populations. For instance, more studies using device-based measures, longitudinal or interventional designs, as well as qualitative and mixed-methods approaches are required.

Enhancing clinical and public health interpretation of accelerometer-assessed physical activity with age-referenced values based on UK Biobank data

BACKGROUND

Higher accelerometer-assessed volume and intensity of physical activity (PA) have been associated with a longer life expectancy but can be difficult to translate into recommended doses of PA. We aimed to: (a) improve interpretability by producing UK Biobank age-referenced centiles for PA volume and intensity; (b) inform public-health messaging by examining how adding recommended quantities of moderate and vigorous PA affect PA volume and intensity.

METHODS

92,480 UK Biobank participants aged 43-80 years with wrist-worn accelerometer data were included. Average acceleration and intensity gradient were derived as proxies for PA volume and intensity. We generated sex-specific centile curves using Generalized Additive Models for Location Scale and Shape (GAMLSS) and modeled the effect of adding moderate (walking) or vigorous (running) activity on the combined change in the volume and intensity centiles (change in PA profile).

RESULTS

In men, volume was lower as age increased while intensity was lower after age 55; in women, both volume and intensity were lower as age increased. Adding 150 min of moderate PA weekly (5×30 min walking) increased the PA profile by 4 percentage points. Defining moderate PA as brisk walking approximately doubled the increase (9 percentage points) while 75 min of vigorous PA weekly (5×15 min running) trebled the increase (13 percentage points).

CONCLUSION

These UK Biobank reference centiles provide a benchmark for interpretation of accelerometer data. Application of our translational methods demonstrate that meeting PA guidelines through shorter duration vigorous activity is more beneficial to the PA profile (volume and intensity) than longer duration moderate activity.

Examining the relationship between different physical activities and health and well-being in middle-aged and older men: an isotemporal substitution analysis

Background

Well-being declines during men's middle years, and while physical activity (PA) can have a positive influence, the type of PA that provides the greatest benefit is not clear. This cross-sectional study explored how participation in different types of PA is associated with the well-being and self-rated health of middle-aged and older men.

Methods

A representative sample of South Australian adults completed a survey which assessed time spent in a variety of physical activities and self-rated health, life worth, life satisfaction and previous day happiness and anxiety. This study focused on a subsample of men≥35 years of age (n=1019). Partition and isotemporal substitution analyses were used to explore relationships between different types of PA and self-rated health and well-being outcomes.

Results

Weekly PA was positively associated with all outcomes among middle-aged men (35-64 years), but only with self-rated health and life satisfaction in older men (65+ years). Substituting out 30 mins of team sport participation with cycling, fitness/gym-based activities or other recreational activities was associated with higher self-rated health in middle-aged men. In older men, substituting 30 mins of dance with most other types of PA was related with greater self-rated health and life worth.

Conclusions

Total weekly PA was consistently related to the self-rated health and well-being of middle-aged men, but less so among older men. Despite some substitution effects for self-rated health, for the most part well-being was not influenced by activity substitution, particularly among middle-aged men.

Effects of replacing sedentary time with alterations in physical activity or sleep on mood states in Chinese young adults during the pandemic

BACKGROUND

Poor mood states pose the most frequent mental health, creating a considerable burden to global public health. Sedentary behavior is an essential factor affecting mood states, however, previous measures to reduce sedentary time in Chinese young adults have focused only on increasing physical activity (PA). Sedentary, PA, and sleep make up a person's day from the standpoint of time use. It is not known whether reallocating sedentary time to different types of PA (e.g. daily PA and structured PA) or sleep during an epidemic has an effect on mood states. Therefore, this study aimed to examine the association between replacing sedentary time with different types of PA or sleep during the pandemic and the mood states of Chinese young adults and to further examine whether this association varies across sleep populations and units of replacement time.

METHOD

3,579 young adults aged 18 to 25 years living in China and self-isolating at home during the COVID-19 outbreak were invited to complete an online questionnaire between February from 23 to 29, 2020. Subjects' PA, sedentary time, and mood states were assessed using the International Physical Activity Questionnaire and the Chinese version of the Profile of Mood States, respectively. Participants also reported sleep duration and some sociodemographic characteristics. Participants were divided into short sleepers (< 7 h/d), normal sleepers (7-9 h/d), and long sleepers (> 9 h/d) based upon their reported sleep duration. Relevant data were analyzed using Pearson correlation analysis and isotemporal substitution model (ISM).

RESULTS

Sedentary time was negatively associated with mood states in Chinese young adults during the pandemic (r = 0.140) and correlated strongest among short sleepers (r = 0.203). Substitution of sedentary time with structured PA was associated with good mood states (β=-0.28, 95% CI: -0.49, -0.08). Additionally, substituting sedentary time with daily PA (e.g. occupational PA, household PA) was also associated with good mood states among normal sleepers (β=-0.24, 95% CI: -0.46, -0.02). The substitution of sedentary time with sleep could bring mood benefits (β=-0.35, 95% CI: -0.47, -0.23). This benefit was particularly prominent among short sleepers. Furthermore, for long sleepers, replacing sedentary time with sleep time also resulted in significant mood benefits (β=-0.41, 95% CI: -0.69, -0.12). The longer the duration of replacing sedentary behavior with different types of PA or sleep, the greater the mood benefits.

CONCLUSIONS

A reallocation of as little as 10 min/day of sedentary time to different types of PA or sleep is beneficial for the mood states of young adults. The longer the reallocation, the greater the benefit. Our results demonstrate a feasible and practical behavior alternative for improving mood states of Chinese young adults.

Isotemporal Substitution Modeling on Sedentary Behaviors and Physical Activity With Mortality Among People With Different Diabetes Statuses: A Prospective Cohort Study From the National Health and Nutrition Examination Survey Analysis 2007-2018

BACKGROUND

To assess the associations of replacing sedentary behavior with different types of physical activity with mortality among the US adults of varying diabetes statuses.

METHODS

This prospective cohort study included 21,637 participants (mean age, 48.5 y) from the National Health and Nutrition Examination Survey 2007-2018. Physical activity including leisure-time moderate-vigorous-intensity activity (MVPA), walking/bicycling, worktime MVPA, and sedentary behavior. We conducted an isotemporal substitution analysis using Cox regression to estimate the associations between replacements and mortality risks.

RESULTS

We found significant protective associations between replacing 30 minutes per day sedentary behavior with 3 types of physical activity and all-cause, cardiovascular disease (CVD) mortality risk (except worktime MVPA for CVD mortality) among total participants, with hazard ratio (HR; 95% confidence interval [CI]) ranging from 0.86 (0.77-0.95) to 0.96 (0.94-0.98). Among participants with diagnosed diabetes, replacing sedentary behavior with leisure-time MVPA was associated with a lower all-cause mortality risk (HR 0.81, 95% CI, 0.70-0.94), which was also observed in other subgroups, with HRs (95% CI) ranging from 0.87 (0.80-0.94) to 0.89 (0.81-0.99). Among those with prediabetes/undiagnosed diabetes, replacing sedentary behavior with walking/bicycling was associated with lower CVD mortality risk, and replacement to work-time MVPA was associated with lower all-cause and CVD mortality risk, with HRs (95% CI) ranging from 0.72 (0.63-0.83) to 0.96 (0.92-0.99).

CONCLUSIONS

Replacing sedentary behaviors with 30 minutes per day leisure-time MVPA was associated with lower all-cause mortality, regardless of diabetes statuses. Among people with prediabetes/undiagnosed diabetes, walking/bicycling was additionally associated with lower CVD mortality, and worktime MVPA was associated with lower all-cause and CVD mortality.

Adherence of Brazilian Minors to the 24-Hour Movement Guidelines after In-Person School Return

The levels of adequacy of movement behaviors after returning to in-person school activities following the COVID-19 pandemic are not yet well understood. This study aimed to assess the adherence of Brazilian minors to the recommendations of the 24-Hour Movement Guidelines (moderate to vigorous physical activity, recreational screen time, and sleep duration), as well as overall adherence to these guidelines, after the relaxation of COVID-19 social isolation measures and the resumption of in-person schooling. A cross-sectional study was conducted with parents or guardians (39 ± 7.8) of minors aged up to 18 years of age (3.8 ± 2.5). A total of 172 individuals responded to the questionnaire. Data were compared with those obtained in the Survey of the Adequacy of Brazilian Children and Adolescents to the 24-Hour Movement Guidelines before and during the COVID-19 Pandemic. There was an 18.6 percentage decrease (p-value < 0.001) in overall adherence to the 24-Hour Movement Guidelines when comparing the periods before the COVID-19 pandemic (March 2020) and after the return to in-person schooling (March 2021). The largest percentage drop in adherence between these periods was observed for moderate to vigorous physical activity (27.4%; p-value < 0.001) and the lowest for sleep (10.5%; p-value < 0.001). Adherence to the 24-Hour Movement Guidelines did not return to pre-pandemic levels with the resumption of in-person school activities.

A biobehavioral observational study to understand the multilevel determinants of cardiovascular health in Black women: the BLOOM Study protocol

BACKGROUND

The racial/ethnic and gender disparities in cardiovascular disease (CVD) morbidity and mortality in the United States are evident. Across nearly every metric, non-Hispanic Black women have poorer overall cardiovascular health. Emerging evidence shows a disproportionately high burden of increased CVD risk factors in Black women of childbearing age, which has a far-reaching impact on both maternal and child outcomes, resulting in premature onset of CVD and further widens the racial disparities in CVD. There is growing recognition that the fundamental driver of persistent racial/ethnic disparities in CVD, as well as disparities in behavioral risk factors such as physical activity and sleep, is structural racism. Further, the lived personal experience of racial discrimination not only has a negative impact on health behaviors, but also links to various physiological pathways to CVD risks, such as internalized stress resulting in a pro-inflammatory state. Limited research, however, has examined the interaction between daily experience and health behaviors, which are influenced by upstream social determinants of health, and the downstream effect on biological/physiological indicators of cardiovascular health in non-pregnant Black women of childbearing age.

METHODS/DESIGN

The BLOOM Study is an observational study that combines real-time ambulatory assessments over a 10-day monitoring period with in-depth cross-sectional lab-based physiological and biological assessments. We will use a wrist-worn actigraphy device to capture 24-h movement behaviors and electronic ecological momentary assessment to capture perceived discrimination, microaggression, and stress. Blood pressure will be captured continuously through a wristband. Saliva samples will be self-collected to assess cortisol level as a biomarker of psychological stress. Lab assessments include a fasting venous blood sample, and assessment of various indices of peripheral and cerebral vascular function/health. Participants' address or primary residence will be used to obtain neighborhood-level built environmental and social environmental characteristics. We plan to enroll 80 healthy Black women who are between 18 and 49 years old for this study.

DISCUSSION

Results from this study will inform the development of multilevel (i.e., individual, interpersonal, and social-environmental levels) lifestyle interventions tailored to Black women based on their lived experiences with the goal of reducing CVD risk.

CLINICALTRIALS

GOV IDENTIFIER

NCT06150989.

Associations between levels of physical literacy and adherence to the 24-h movement guidelines among university students: A cross-sectional study

Objectives

Emerging evidence indicates that the composition of movement behaviours within a 24-h period is associated with multiple health benefits across the lifespan. A concept that emphasises an individual's active lifestyle is physical literacy (PL), yet empirical research exploring the potential associations between PL and 24-h movement guidelines remains scarce. This study aimed to evaluate the associations between levels of PL and adherence to the guidelines among Chinese university students.

Study design

A cross-sectional study.

Methods

Seven hundred and ninety-eight university students (390 male, 19.2 ± 1.2 years) completed all the measurements. Levels of PL and participants' adherence to guidelines including physical activity, sedentary behaviour and sleep were self-reported through Perceived Physical Literacy Instrument, International Physical Activity Questionnaire and Pittsburgh Sleep Quality Index, respectively. Two-way ANOVA was conducted to determine the associations between the number of guidelines met (0, 1, 2, or 3) and levels of PL.

Results

The results demonstrate that 36.5% (n = 291) of the participants met all the three guidelines, while 4.1% (n = 33) met none. Further analysis indicated that meeting physical activity or sedentary behaviour guidelines was associated with significantly higher total PL scores, and scores in the sub-domains of Confidence and Physical Competence and Motivation.

Conclusions

The findings provide evidence that young adults who obtained higher PL scores may meet more guidelines during a 24-h period. Future studies should incorporate accelerometer-based physical activity measurements and investigate the causal relationship between PL and adherence to the movement guidelines.

Associations of 24 h time-use compositions of sitting, standing, physical activity and sleeping with optimal cardiometabolic risk and glycaemic control: The Maastricht Study

AIMS/HYPOTHESIS

The associations of sitting, standing, physical activity and sleep with cardiometabolic health and glycaemic control markers are interrelated. We aimed to identify 24 h time-use compositions associated with optimal metabolic and glycaemic control and determine whether these varied by diabetes status.

METHODS

Thigh-worn activPAL data from 2388 participants aged 40-75 years (48.7% female; mean age 60.1 [SD = 8.1] years; n=684 with type 2 diabetes) in The Maastricht Study were examined. Compositional isometric log ratios were generated from mean 24 h time use (sitting, standing, light-intensity physical activity [LPA], moderate-to-vigorous physical activity [MVPA] and sleeping) and regressed with outcomes of waist circumference, fasting plasma glucose (FPG), 2 h plasma glucose, HbA1c, the Matsuda index expressed as z scores, and with a clustered cardiometabolic risk score. Overall analyses were adjusted for demographics, smoking, dietary intake and diabetes status, and interaction by diabetes status was examined separately. The estimated difference when substituting 30 min of one behaviour with another was determined with isotemporal substitution. To identify optimal time use, all combinations of 24 h compositions possible within the study footprint (1st-99th percentile of each behaviour) were investigated to determine those cross-sectionally associated with the most-optimal outcome (top 5%) for each outcome measure.

RESULTS

Compositions lower in sitting time and with greater standing time, physical activity and sleeping had the most beneficial associations with outcomes. Associations were stronger in participants with type 2 diabetes (p<0.05 for interactions), with larger estimated benefits for waist circumference, FPG and HbA1c when sitting was replaced by LPA or MVPA in those with type 2 diabetes vs the overall sample. The mean (range) optimal compositions of 24 h time use, considering all outcomes, were 6 h (range 5 h 40 min-7 h 10 min) for sitting, 5 h 10 min (4 h 10 min-6 h 10 min) for standing, 2 h 10 min (2 h-2 h 20 min) for LPA, 2 h 10 min (1 h 40 min-2 h 20 min) for MVPA and 8 h 20 min (7 h 30 min-9 h) for sleeping.

CONCLUSIONS/INTERPRETATION

Shorter sitting time and more time spent standing, undergoing physical activity and sleeping are associated with preferable cardiometabolic health. The substitutions of behavioural time use were significantly stronger in their associations with glycaemic control in those with type 2 diabetes compared with those with normoglycaemic metabolism, especially when sitting time was balanced with greater physical activity.

Longitudinal Associations between 24-h Movement Behaviors and Cardiometabolic Biomarkers: A Natural Experiment over Retirement

INTRODUCTION

Physical activity, sedentary behavior, and sleep, that is, 24-h movement behaviors, often change in the transition from work to retirement, which may affect cardiometabolic health. This study investigates the longitudinal associations between changes in 24-h movement behaviors and cardiometabolic biomarkers during the retirement transition.

METHODS

Retiring public sector workers ( n = 212; mean (SD) age, 63.5 (1.1) yr) from the Finnish Retirement and Aging study used a thigh-worn Axivity accelerometer and filled out a diary to obtain data on daily time spent in sedentary behavior (SED), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA), and sleep before and after retirement (1 yr in-between). Cardiometabolic biomarkers, including LDL-cholesterol, HDL-cholesterol, total/HDL-cholesterol ratio, triglycerides, C-reactive protein, fasting glucose, and insulin, were measured. Associations between changes in 24-h movement behaviors and cardiometabolic biomarkers were analyzed using compositional robust regression and isotemporal substitution analysis.

RESULTS

Increasing LPA in relation to remaining behaviors was associated with an increase in HDL-cholesterol and decrease in total/HDL-cholesterol ratio ( P < 0.05 for both). For instance, reallocation of 30 min from sleep/SED to LPA was associated with an increase in HDL-cholesterol by 0.02 mmol·L -1 . Moreover, increasing MVPA in relation to remaining behaviors was associated with a decrease in triglycerides ( P = 0.02). Reallocation of 30 min from SED/sleep to MVPA was associated with 0.07-0.08 mmol·L -1 decrease in triglycerides. Findings related to LDL-cholesterol, C-reactive protein, fasting glucose, and insulin were less conclusive.

CONCLUSIONS

During the transition from work to retirement, increasing physical activity at the expense of passive behaviors was associated with a better lipid profile. Our findings suggest that life transitions like retirement could be utilized more as an optimal time window for promoting physical activity and health.

Accelerometer-Based Estimates of Physical Activity and Sedentary Time Among Samoan Adults

BACKGROUND

The prevalence of obesity-related cardiometabolic disease in Samoa is among the highest globally. While physical activity is a modifiable risk factor for obesity-related disease, little is known about physical activity levels among adult Samoans. Using wrist-worn accelerometer-based devices, this study aimed to characterize physical activity among Samoan adults.

METHODS

Samoan adults (n = 385; 55% female, mean [SD] age 52 [10] y) wore Actigraph GT3X+ devices for 7 to 10 days. General linear models were used to examine mean daily minutes of sedentary time, light physical activity, and moderate to vigorous physical activity by various participant characteristics.

RESULTS

Time spent in moderate to vigorous physical activity did not differ statistically between men (88 [5] min; 95% confidence interval [CI], 80-97) and women (78 [4] min; 95% CI, 70-86; P = .08). Women, however, spent more time than men in light physical activity: 380 (7) minutes (95% CI, 367-393) versus 344 (7) minutes (95% CI, 329-358; P < .001). While there were no differences in physical activity by census region, education, or occupation among women, men in urban areas spent significantly less time in moderate to vigorous physical activity than those in peri-urban and rural areas (P = .015). Women with class II/III obesity spent more time in sedentary activities than those with healthy weight or overweight/class I obesity (P = .048).

CONCLUSIONS

This study characterizes physical activity among Samoan adults and highlights variation by sex, urbanicity, and weight status. In providing initial device-measured estimates of physical activity in Samoa, this analysis establishes a baseline from which the success of future attempts to intervene on physical activity may be assessed.

Sedentary Behaviors, Light-Intensity Physical Activity, and Healthy Aging

Importance

Sleep duration and moderate-to-vigorous physical activity (MVPA) are associated with healthy aging, but the associations of sedentary behaviors and light-intensity physical activity (LPA) with healthy aging are still unclear.

Objective

To examine the independent association of sedentary behaviors and LPA with healthy aging, and to estimate the theoretical association of replacing sedentary behavior with LPA, MVPA, or sleep with healthy aging.

Design, Setting, and Participants

In this cohort study using data from the Nurses' Health Study, participants aged 50 years or older and free of major chronic diseases in 1992 were prospectively followed up for 20 years. Data were analyzed from January to May 2022.

Exposures

Three measures for sedentary behaviors (hours watching television, sitting at work, and other sitting at home) and 2 measures for LPA (hours of standing or walking around at home [LPA-Home] and at work [LPA-Work]).

Main Outcomes and Measures

Healthy aging was defined as survival to at least age 70 years with maintenance of 4 health domains (ie, no major chronic diseases and no impairment in subjective memory, physical function, or mental health). The isotemporal substitution model was used to evaluate the potential impact on healthy aging of replacing 1 hour of 1 behavior with equivalent duration of another.

Results

Among 45 176 participants (mean [SD] age, 59.2 [6.0] years), 3873 (8.6%) women achieved healthy aging. After adjustment for covariates including MVPA, each increment of 2 hours per day in sitting watching television was associated with a 12% (95% CI, 7%-17%) reduction in the odds of healthy aging. In contrast, each increase of 2 hours per day in LPA-Work was associated with a 6% (95% CI, 3%-9%) increase in the odds of healthy aging. Replacing 1 hour of sitting watching television with LPA-Home (OR, 1.08; 95% CI, 1.05-1.12), LPA-Work (OR, 1.10; 95% CI, 1.07-1.14), or MVPA (OR, 1.28; 95% CI, 1.23-1.34) was associated with increased odds of healthy aging. Among participants who slept 7 hours per day or less, replacing television time with sleep was also associated with increased odds of healthy aging.

Conclusions and Relevance

In this cohort study, longer television watching time decreased odds of healthy aging, whereas LPA and MVPA increased odds of healthy aging and replacing sitting watching television with LPA or MVPA, or with sleep in those who slept 7 hours per day or less, was associated with increased odds of healthy aging, providing evidence for rearranging 24-hour behavior to promote overall health.

The effect of replacing sedentary behavior with different intensities of physical activity on depression and anxiety in Chinese university students: an isotemporal substitution model

BACKGROUND

Previous research has suggested that engaging in regular physical activity (PA) can help to reduce symptoms of depression and anxiety in university students. However, there is a lack of evidence regarding the impact of reducing sedentary behavior (SB) and increasing light-intensity PA (LPA) on these symptoms. This study aims to address this gap by using isotemporal substitution (IS) models to explore how substituting SB with LPA or moderate-to-vigorous PA (MVPA) affects depression and anxiety symptoms among university students.

METHODS

The study recruited 318 university students with a mean age of 21.13 years. Accelerometers were used to objectively measure the time spent on SB, LPA, and MVPA, while depression and anxiety symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D) and the Self-rating Anxiety Scale (SAS). IS models using multivariable linear regression were employed to estimate the associations between different behaviors and depression and anxiety symptoms when 30 min of one behavior was substituted with another.

RESULTS

In the single-activity model, less SB (β = 0.321, 95% CI: 0.089, 1.297) and more MVPA (β = -0.142, 95% CI: -1.496, - 0.071) were found to be significantly and negatively associated with depression scores, while less SB (β = 0.343, 95% CI: 0.057, 1.014), LPA (β = 0.132, 95% CI: 0.049, 1.023), and more MVPA (β = -0.077, 95% CI: -1.446, - 0.052) were significantly and negatively correlated with anxiety scores. The IS analysis revealed that substituting 30 min of SB with LPA (β = -0.202, 95% CI: -1.371, - 0.146) or MVPA (β = -0.308, 95% CI: -0.970, - 0.073) was associated with improvements in depressive symptoms. Substituting 30 min of SB with MVPA (β = -0.147, 95% CI: -1.863, - 0.034) was associated with reduced anxiety symptoms.

CONCLUSION

Replacing 30 min of SB with MVPA may alleviate depression and anxiety symptoms in university students. Further research is needed to explore the long-term effects of PA interventions on the mental health disorders of this population.

Promoting a healthy lifestyle: exploring the role of social media and fitness applications in the context of social media addiction risk

The popularity of social networks turns them into a legal method for promoting a healthy lifestyle, which benefits not only people but also different countries' governments. This research paper aimed to examine the Keep fitness app integrated into WeChat, Weibo and QQ as regards long-term improvements in health-related behaviors (physical activity, nutrition, health responsibility, spiritual growth, interpersonal relationships and stress management) and assess the associated risk of increased social media addiction. Students from Lishui University in China (N = 300) participated in this study, and they were formed into control and experimental groups. The Healthy Lifestyle Behavior Scale and Social Media Disorder Scale were used as psychometric instruments. The Keep app was found to improve respondents' scores on the parameters of physical activity, nutrition and health responsibility (P = 0.00). However, the level of dependence on social media did not change in either the control or the experimental group during the year of research (P ≥ 0.05). It is concluded that fitness apps can be an effective tool to promote healthy lifestyles among young people in China and other countries. The feasibility of government investment in fitness apps to promote healthy lifestyles is substantiated.

Substitutions of physical activity and sedentary behavior with negative emotions and sex difference among college students

BACKGROUND

A growing number of studies have found that physical activity (PA) benefits mental health, and sedentary behavior (SB) increases the risk of psychological symptoms, but it remains unclear whether substituting the duration of different activities may affect the association, and whether sex difference exists among college students.

METHODS

A longitudinal survey was conducted in three colleges in Anhui province, China. A total of 8049 participants validly answered the questionnaire, which included demographic variables, PA, SB and negative emotions (depressive, anxiety, and stress symptoms).

RESULTS

Substituting 30 min per day of SB with equivalent walking was associated with lower scores of depressive symptoms. Stress symptoms were reduced when SB was substituted by moderate intensity PA (MPA) and walking. Substituting 30 min per day of MPA in place of walking and SB was associated with an amelioration of depressive and stress symptoms in females, and a reallocation of 30 min walking was associated with lower depressive and stress symptom scores when SB was replaced in males.

CONCLUSIONS

Replacing SB with walking and MPA ameliorates the depressive and stress symptoms in young adults. The results suggest a reallocation of time from SB or walking to MPA in females while from SB to walking in males may markedly reduce the depressive and stress symptoms in college population.

Effects of substituting sedentary time with physical activity on body mass index in Japanese adults with Down syndrome: A cross-sectional study

Objective

and Rationale: Obesity is a health challenge for adults with Down syndrome. Therefore, a physical activity promotion program is required to prevent or reduce obesity in adults with this condition. However, there is a lack of evidence of useful risk reduction initiatives. The objective of this study was to suggest a rationale for behaviors that should replace time of inactivity to reduce obesity in Japanese adults with Down syndrome.

Methods

The participants were adults with Down syndrome, aged 18-48 years, living in Japan. The snowball sampling method was used. To detect an effect size of 0.20 for body mass index using an F-test, 80 participants were required, generating a statistical power of 0.8 and a risk level of 0.05. Survey items included sex, age, height, weight, body mass index, and physical activity (min/d). Physical activity was categorized by intensity and further divided into ambulatory and non-ambulatory activities. The body mass index categories were compared using analysis of covariance. An isotemporal substitution model was used to confirm the interdependence of behaviors.

Results

Half of the participants were obese, with a body mass index of 25 kg/m2 or higher. The obese group had significantly fewer light physical activity, moderate-to-vigorous physical activity, and ambulatory moderate-to-vigorous physical activity times than the non-obese group. Replacing 10 min of sedentary behavior with ambulatory moderate-to-vigorous physical activity was significantly associated with a lower body mass index.

Conclusions

This study suggests a rationale for behaviors that should replace time of inactivity to reduce obesity in adults with Down syndrome. Specifically, replacing 10 min of sedentary behavior with ambulatory moderate-to-vigorous physical activity time may contribute to obesity reduction.

Association between accelerometer-derived physical activity and depression: a cross-sectional study using isotemporal substitution analysis

OBJECTIVES

Depression is a significant public health concern, and physical activity has been identified as a non-pharmacological intervention. Understanding the dose-response relationship between physical activity and depression is crucial for designing effective exercise interventions and recommending physical activity to individuals with depression. The isotemporal substitution model is considered the gold standard for estimating the dose-response effects of physical activity. This study aims to investigate the dose-response association between depression and accelerometer-measured physical activity in the Korean population.

DESIGN

Cross-sectional analysis.

SETTING

A non-probability sample of the community population was drawn from the 2014 and 2016 Korean National Health and Nutrition Examination Survey.

PARTICIPANTS

The study included 1543 adults aged 19-64 years who completed the Patient Health Questionnaire-9 (PHQ-9) and volunteered to wear an accelerometer.

MAIN OUTCOME MEASURES

Physical activity was measured using a GT3X+ accelerometer for 7 consecutive days, and activity was categorised as sedentary behaviour (SB) or light, moderate or vigorous physical activity. Depression was assessed using the PHQ-9.

RESULTS

Physical activity and SB were associated with depression. In the single-parameter model, moderate-vigorous physical activity (MVPA) showed a significant association with reduced odds of depression (OR: 0.817, 95% CI: 0.678 to 0.985). Substituting 30 min of SB with 30 min of MVPA (OR: 0.815, 95% CI: 0.669 to 0.992) was linked to a decrease in the odds of depression. Conversely, replacing 30 min of MVPA with 30 min of SB (OR: 1.227, 95% CI: 1.008 to 1.495) was associated with an increase in the odds of depression.

CONCLUSIONS

This study provides evidence of an association between physical activity and depression in the Korean population, highlighting the importance of reducing SB and increasing MVPA to prevent and manage depression. Further research is needed to confirm causality and determine optimal levels of physical activity for preventing depression in different populations.

Longitudinal associations of screen time, physical activity, and sleep duration with body mass index in U.S. youth

BACKGROUND

Youth use different forms of screen time (e.g., streaming, gaming) that may be related to body mass index (BMI). Screen time is non-independent from other behaviors, including physical activity and sleep duration. Statistical approaches such as isotemporal substitution or compositional data analysis (CoDA) can model associations between these non-independent behaviors and health outcomes. Few studies have examined different types of screen time, physical activity, and sleep duration simultaneously in relation to BMI.

METHODS

Data were baseline (2017-2018) and one-year follow-up (2018-2019) from the Adolescent Brain Cognitive Development Study, a multi-site study of a nationally representative sample of U.S. youth (N = 10,544, mean [SE] baseline age = 9.9 [0.03] years, 48.9% female, 45.4% non-White). Participants reported daily minutes of screen time (streaming, gaming, socializing), physical activity, and sleep. Sex-stratified models estimated the association between baseline behaviors and follow-up BMI z-score, controlling for demographic characteristics, internalizing symptoms, and BMI z-score at baseline.

RESULTS

In females, isotemporal substitution models estimated that replacing 30 min of socializing (β [95% CI] = -0.03 [-0.05, -0.002]), streaming (-0.03 [-0.05, -0.01]), or gaming (-0.03 [-0.06, -0.01]) with 30 min of physical activity was associated with a lower follow-up BMI z-score. In males, replacing 30 min of socializing (-0.03 [-0.05, -0.01]), streaming (-0.02 [-0.03, -0.01]), or gaming (-0.02 [-0.03, -0.01]) with 30 min of sleep was associated with a lower follow-up BMI z-score. In males, replacing 30 min of socializing with 30 min of gaming was associated with a lower follow-up BMI z-score (-0.01 [-0.03, -0.0001]). CoDA estimated that in males, a greater proportion of time spent in baseline socializing, relative to the remaining behaviors, was associated with a higher follow-up BMI z-score (0.05 [0.02, 0.08]). In females, no associations between screen time and BMI were observed using CoDA.

CONCLUSIONS

One-year longitudinal associations between screen time and BMI may depend on form of screen time, what behavior it replaces (physical activity or sleep), and participant sex. The alternative statistical approaches yielded somewhat different results. Experimental manipulation of screen time and investigation of biopsychosocial mechanisms underlying the observed sex differences will allow for causal inference and can inform interventions.

Substituting Book Reading for Screen Time Benefits Preschoolers' Sleep Health: Results from the Ulm SPATZ Health Study

Purpose

Healthy sleep is essential for the physical, cognitive, and social development of children. Several studies have reported the increase in digital media use in preschool children and its association with impaired sleep. However, there is relatively little evidence on the effects of book reading as a potentially safe alternative. The objective of this study, therefore, was to investigate whether sleep in children could benefit from book reading, and whether the negative effects of media use on sleep can be mitigated by substituting book reading for screen time.

Participants and Methods

We used longitudinal data from three consecutive waves of the SPATZ Health study, including children at the ages of 4 (n=581), 5 (n=508), and 6 (n=426) years. All data were collected by self-administered questionnaires. Parent-reported child sleep was assessed by the Children's Sleep Habits Questionnaire.

Results

Across the three waves, screen-based media use increased and was associated with lower sleep quality. In contrast, the time spent with book reading decreased; however, book reading appeared to be beneficial for children's sleep. Substitution models revealed that the theoretical substitution of an equal amount of book reading for 50% of the time spent with screen-based media benefits several domains of preschoolers' sleep health, including parasomnias, sleep anxiety, daytime sleepiness, and sleep onset delay.

Conclusion

Besides implications for population-wide and individual prevention, book reading may also be incorporated as a useful intervention to improve sleep quality in children who are already affected by sleep problems. Given that book reading is perceived as a safe alternative, the presented evidence may suffice to support recommendations in this direction.

Isotemporal substitution analysis of time between sleep, sedentary behavior, and physical activity on depressive symptoms in older adults: a cross-sectional study

BACKGROUND

Compared to young individuals, older adults participate more in sedentary behavior (SB) and less in physical activity (PA). These behaviors are associated with numerous adverse health factors.

OBJECTIVE

The purpose of the study was to examine the hypothetical effects of substituting time spent sleeping, performing SB, and performing moderate-to-vigorous physical activity (MVPA) on depressive symptomatology in older adults.

DESIGN AND SETTING

An analytical cross-sectional study employing exploratory survey methods was conducted in the city of Alcobaça in the state of Bahia, Brazil.

METHODS

The study included 473 older adults who answered a structured questionnaire during an interview. Exposure time to SB and PA level were assessed using the International Physical Activity Questionnaire, and depressive symptoms were analyzed using the short version of the Geriatric Depression Scale. An isotemporal replacement model was used to evaluate the effects of different SB sessions on depressive symptomatology.

RESULTS

An increase in the risk of depressive symptoms was observed when MVPA and sleep time were substituted for the same SB time at all times tested, with maximum values of 40% and 20%, respectively. Opposite substitution of MVPA and sleep time increments reduced the risk of depressive symptomatology by 28% and 17%, respectively.

CONCLUSIONS

The results of the present study indicate that replacing SB with the same amount of sleep or MVPA may reduce depressive symptoms. The longer the reallocation time, the greater are the benefits.

High levels of sleep disturbance across early childhood increases cardiometabolic disease risk index in early adolescence: longitudinal sleep analysis using the Health Outcomes and Measures of the Environment study

STUDY OBJECTIVES

This study examines the impact of sleep duration, bedtime, and sleep disturbance during early childhood on the risk of cardiometabolic disorder (CMD) in early adolescence.

METHODS

Within the Health Outcomes and Measures of Environment Study, we examined sleep patterns of 330 children from ages 2 to 8 years and the relationship of these sleep patterns with cardiometabolic risk measures at age 12 (N = 220). We used a group-based semi-parametric mixture model to identify distinct trajectories in sleep duration, bedtime timing, and sleep disturbance for the entire sample. We then examined the associations between sleep trajectories and CMD risk measures using general linear models using both an unadjusted model (no covariates) and an adjusted model (adjusting for child pubertal stage, child sex, duration of breastfeeding, household income, maternal education, and maternal serum cotinine).

RESULTS

In the unadjusted and adjusted models, we found significant differences in CMD risk scores by trajectories of sleep disturbance. Children in the "high" disturbance trajectory had higher CMD risk scores than those in the 'low' disturbance trajectory (p's = 0.002 and 0.039, respectively). No significant differences in CMD risk were observed for bedtime timing or total sleep time trajectories in the unadjusted or adjusted models.

CONCLUSIONS

In this cohort, caregiver-reported sleep disturbance in early childhood was associated with more adverse cardiometabolic profiles in early adolescence. Our findings suggest that trials to reduce CMD risk via sleep interventions-which have been conducted in adolescents and adults-may be implemented too late.

Replacing screen time, with physical activity and sleep time: influence on cardiovascular indicators and inflammatory markers in Brazilian children

OBJECTIVE

To examine if the substitution of different screen time intervals with light physical activity (LPA), moderate to vigorous physical activity (MVPA) and sleep is associated with cardiovascular indicators and inflammatory markers in children.

METHODS

This is a cross-sectional study developed with 186 children aged between six and 11 years old from public schools in southern Brazil. CRF was measured with the 6-minute running and walking test, following the Brazil Sports Project procedures. The percentage of fat was evaluated through DXA. LPA and MVPA were measured using accelerometers. Sleep and screen time were assessed by questionnaires answered by parents. Leptin and C-reactive protein were measured by fasting blood collection. Systolic and diastolic blood pressure were determined through a digital sphygmomanometer. Isotemporal substitution models were used for statistical analysis.

RESULTS

Replacing 1 h of screen time with MVPA was associated with lower BMI, systolic and diastolic blood pressure, fat percentage, leptin, and C-reactive protein. When screen time was substituted for sleep time, lower waist circumference was observed. Regarding the substitution of 1 h of screen time with LPA, significant values were found only for leptin.

CONCLUSION

The replacement of screen time with physical activities of different intensities and sleep time was associated with benefits in cardiovascular indicators and inflammatory markers in childhood.

The relationship between nighttime exercise and problematic smartphone use before sleep and associated health issues: a cross-sectional study

OBJECTIVE

Physical exercise has the potential to mitigate addictive behaviors and relevant health issues. However, the nighttime exercise has not been studied regarding this research topic. This study aims to explore the association between nocturnal physical exercise and problematic smartphone use before sleep, as well as related health issues.

METHODS

To explore the association between nighttime physical exercise and problematic smartphone use before sleep as well as related health issues, we conducted a cross-sectional survey among 1,334 college students. Their daily exercise behaviors (including timeframe, rationale, frequency, and duration), smartphone use before sleep, sleep quality, smartphone addiction, anxiety, and depression were measured by questionnaires. The associations were assessed using generalized linear models.

RESULTS

Our findings indicate that nearly 70% of participants chose to perform exercise at nighttime. Among these individuals who exercised at nighttime, the frequency and duration of nighttime exercise were significantly associated with decreased probabilities of smartphone use before sleep. Additionally, the frequency and duration of nighttime exercise were associated with lower levels of smartphone addiction and anxiety disorders.

CONCLUSION

Nighttime Exercise behaviors can effectively reduce sleep delays caused by problematic smartphone use before bedtime. These findings contribute to understanding the potential effects of nighttime exercise on problematic smartphone use and relevant health issues. Future research should employ more precise methodologies to examine these associations.

Associations of meeting 24-h movement guidelines and metabolic syndrome in Korean adults during the COVID-19 pandemic

OBJECTIVES

This study aimed to investigate the association between adherence to 24-h movement guidelines and metabolic syndrome (MetS) before and during the COVID-19 pandemic.

STUDY DESIGN

Repeated cross-sectional design.

METHODS

We selected 10,882 adults (2019: n = 5710; 2020: n = 5172) aged ≥20 years from the Korea National Health and Nutrition Examination Survey. Domain-specific physical activity and sedentary behavior were assessed using a global physical activity questionnaire. We also measured the typical sleep duration (h/day) on weekdays and weekends. MetS was defined as the presence of more than three risk factors.

RESULTS

During the COVID-19 pandemic, transportation-related physical activity decreased, while the prevalence of abdominal obesity (+3.3 %) and low HDL-C levels (+3.1 %) increased significantly. An elevated risk of MetS was observed in the lower aerobic (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.04-1.58; P = 0.019) and muscular exercise (OR, 1.31; 95% CI, 1.04-1.66; P = 0.023) groups and in the high sedentary behavior (OR, 1.23; 95% CI, 1.00-1.51; P = 0.049) during the pandemic. Sensitivity analysis stratified by sex showed similar patterns with more pronounced changes in MetS components in males. The models also showed significant associations between aerobic physical activity, strength exercises, and sedentary behavior with MetS in males and females.

CONCLUSIONS

Although sedentary behavior and sleep time remained unchanged, a significant decrease in transportation-related physical activity was observed during the pandemic. Moreover, our findings revealed that aerobic physical activity, strength exercise, and sedentary time during the pandemic were associated with an increased MetS risk. These results highlight the importance of promoting physical activity, particularly during periods of social restriction, to mitigate the pandemic's negative effects on metabolic health.

Knowledge, attitudes, and practices regarding cardiovascular disease prevention among middle school students in China: a cross-sectional study

Background

The prevalence of cardiovascular disease (CVD) is rapidly increasing globally. With a concerning increase among adolescents due to unhealthy habits, obesity, and hypertension, understanding the current status of knowledge, attitudes, and practices (KAP) related to CVD prevention among middle school students is crucial for developing effective school-based health programs to prevent CVD.

Methods

The analytic cross-sectional survey is used in questionnaires to assess KAP related to CVD prevention among middle school students (N = 17,731) from 50 schools across 16 provinces in China in June-July 2023. The pass rate of KAP scores is categorized as good and poor. Independent predictors of good KAP of CVD prevention are ascertained using a binary logistic regression model.

Results

The study surveyed 8,118 (45.78%) junior high school students and 9,613 (54.22%) high school students. The overall mean [standard deviation (SD)] for the knowledge, attitude, and practice scores were 26.88 (8.12), 53.53 (7.22), and 39.80 (5.96), respectively. The knowledge scores had the lowest pass rate at 56.89%. Only 6.83% of the students know "the definition of blood pressure in adolescents." Attitudes toward health were positive, though the attitude regarding "the danger of prolonged sedentary to cardiovascular health" scored lowest at 73.55%. The practice section had a pass rate of 89.30%; 40.27% of students reported that they spend more than an hour a day on screens. Only one-third of the students would go to bed before 12 o'clock. In univariate analysis, junior high school and high school students differed significantly in knowledge and practice (p < 0.001), but attitude did not differ significantly (p = 0.103).

Conclusion

The majority of students lack sufficient knowledge about CVD. It is also found that socioeconomic background, family environment, and educational levels have an impact on cardiovascular health behaviors among students. Strengthening health education involving students, parents, teachers, and communities is essential to promote health knowledge and practices among adolescents.

Reallocating time between device-measured 24-hour activities and cardiovascular risk in Asian American immigrant women: An isotemporal substitution model

The 24-hour day consists of physical activity (PA), sedentary behavior, and sleep, and changing the time spent on one activity affects the others. Little is known about the impact of such changes on cardiovascular risk, particularly in Asian American immigrant (AAI) women, who not only have a higher cardiovascular risk but also place greater cultural value on family and domestic responsibilities compared to other racial/ethnic groups. The purpose of this study was to evaluate the effects of reallocating 30 minutes of each 24-hour activity component for another on BMI, waist circumference, and blood pressure in AAI women. Seventy-five AAI women completed 7 days of hip and wrist actigraphy monitoring and were included in the analysis (age = 61.5±8.0 years, BMI = 25.5±3.6 kg/m2, waist circumference = 85.9±10.2 cm). Sleep was identified from wrist actigraphy data, and moderate-to-vigorous PA (MVPA), light PA, and sedentary behavior identified from hip actigraphy data. On average, the women spent 0.5 hours in MVPA, 6.2 hours in light PA, 10 hours in sedentary activities, and 5.3 hours sleeping within a 24-hour day. According to the isotemporal substitution models, replacing 30 minutes of sedentary behavior with MVPA reduced BMI by 1.4 kg/m2 and waist circumference by 4.0 cm. Replacing that same sedentary time with sleep reduced BMI by 0.5 kg/m2 and waist circumference by 1.4 cm. Replacing 30 minutes of light PA with MVPA decreased BMI by 1.6 kg/m2 and waist circumference by 4.3 cm. Replacing 30 minutes of light PA with sleep also reduced BMI by 0.8 kg/m2 and waist circumference by 1.7 cm. However, none of the behavioral substitutions affected blood pressure. Considering AAI women's short sleep duration, replacing their sedentary time with sleep might be a feasible strategy to reduce their BMI and waist circumference.

Replacing device-measured sedentary time with physical activity is associated with lower risk of coronary heart disease regardless of genetic risk

BACKGROUND

Excess sedentary time (ST) is recognized as an important modifiable risk factor for coronary heart disease (CHD). However, whether the associations of genetic susceptibility with CHD incidence can be modified by replacing wearable-device-measured ST with physical activity (PA) is unknown.

OBJECTIVES

To examine the associations of wearable-device-measured ST replaced by PA with incident CHD across strata of genetic susceptibility.

METHODS

This study included 77,500 White British (57% female) with valid wrist-worn accelerometry and without prevalent CHD/stroke from UK Biobank. Genetic susceptibility to CHD was quantified through weighted polygenic risk scores for CHD based on 300 single-nucleotide polymorphisms. Wrist-worn accelerometer data were used to derive ST, light PA, and moderate-to-vigorous PA (MVPA).

RESULTS

Reallocation of 60 min/day of ST into the same amount of MVPA was associated with approximately 9% lower relative risk of CHD for all participants and across strata of genetic risk: replacement of 1 min/day of ST associated with <1% lower relative risk of CHD. No evidence of interaction (p: 0.784) was found between genetic risk and ST for CHD risk. Reallocating 60 min/day of ST into the same MVPA time was associated with greater absolute CHD risk reductions at high genetic risk (0.27%) versus low genetic risk (0.15%).

CONCLUSIONS

Replacing any amount of ST with an equal amount of MVPA time is associated with a lower relative risk of CHD, irrespective of genetic susceptibility to CHD. Reductions in CHD absolute risk for replacing ST with MVPA are greater at high genetic risk versus low genetic risk.

Reallocating desk workers' sitting time to standing or stepping: associations with work performance

BACKGROUND

Studies have suggested that sitting time at work may lead to underperformance but they may underestimate the benefits to desk workers' performance of reducing occupational sitting time without considering the relative effects of the specific activities replaced.

AIMS

To estimate differences in work performance (presenteeism, absenteeism and engagement) when occupational sitting time is reallocated to standing/stepping in desk workers.

METHODS

Data for middle-aged desk workers were from a Japan-wide online survey (n = 2228). Self-report proportion of occupational sitting and standing/stepping, work hours and work performance indicators, including absolute (ratings relating only to self) and relative (ratings of self, compared to others) presenteeism and absenteeism, and dimensions of work engagement, were collected. Partition and isotemporal substitution models were used to investigate the associations of occupational sitting and standing/stepping time with work performance, including their reallocation effects.

RESULTS

In partition models, longer occupational sitting time was associated with a lower absolute presenteeism score (i.e. less productivity), lower absolute absenteeism (i.e. longer-than-expected work hours), and lower engagement. Longer occupational standing/stepping time was associated with lower absolute absenteeism and more engagement. Isotemporal substitution models showed that each hour of occupational sitting reallocated to standing/stepping was favourably associated with overall work engagement (B = 0.087; 95% confidence interval 0.051, 0.122) and its dimensions (B ranged from 0.078 to 0.092), but was not associated with presenteeism or absenteeism.

CONCLUSIONS

These findings suggest that management support and practical initiatives to encourage desk workers to replace portions of their sitting time with standing/stepping may contribute to enhanced work engagement.

A time compositional analysis of the association between movement behaviors and indicators of mental health in young adults

BACKGROUND

Movement behaviors (i.e., physical activity [PA], sedentary behaviors [SB], sleep) relate to mental health. Although movement behaviors are often analyzed as distinct entities, they are in fact highly inter-dependent (e.g., if an individual increases sleep, then PA and/or SB must be reduced) and these dependencies should be accounted for in the analysis. We tested whether perceptions of time spent in movement behaviors (i.e., moderate-to-vigorous intensity PA [MVPA], light physical activity [LPA], SB, and sleep) related to depressive symptoms and self-report mental health in young adults using a compositional analysis. We then estimated change in depressive symptoms with reallocation of time across movement behaviors using compositional time-reallocation models.

METHODS

Data were drawn from the longitudinal NDIT dataset. Complete data were available for 770 young adults (Mage  = 20.3, 55% females).

RESULTS

The proportion of time spent in MVPA relative to other movement behaviors related to depressive symptoms non-significantly and to mental health significantly. Reallocating 15 min from MVPA to SB resulted in a significant (0.46 unit) increase in depressive symptoms, and reallocating 15 min of MVPA to LPA was associated with a (0.57) increase in depressive symptoms.

CONCLUSION

These results indicate the importance of relative time spent in each movement behavior to mental health. Further research should examine these associations over time.

Time Reallocations From Sedentary Behavior to Physical Activity and Cardiovascular Risk Factors in Children and Adolescents: A Systematic Review

BACKGROUND

Recent statistical approaches have allowed consideration of the integrated relationships between sedentary behavior (SB) and physical activity (PA) with different health outcomes. The present paper aimed to systematically review the literature and synthesize evidence about associations between hypothetical reallocations from SB to different PA intensities and cardiovascular risk factors in youth.

METHODS

A systematic search of 8 databases was performed. Observational studies with a population of children and/or adolescents and based on statistical analysis that investigated the associations between time reallocations from SB to PA and cardiovascular risk factors were included.

RESULTS

Twenty-eight studies met the inclusion criteria. Level of evidence (derived from cross-sectional studies) indicated that the reallocation from SB to moderate to vigorous PA was beneficially associated with adiposity, cardiorespiratory fitness, and cardiometabolic biomarkers in youth. Reallocation from SB to light PA was not associated with the analyzed outcomes. Associations derived from longitudinal studies were mostly inconclusive.

CONCLUSION

Cardiovascular risk factors could be improved by increasing moderate to vigorous PA at the expense of time spent in SB in pediatric populations. Prospective studies or studies investigating the effects of reallocating sedentary bouts to PA are needed.

Correlation analysis between physical activity and depressive tendencies among occupational groups: an isotemporal substitution approach

OBJECTIVES

Sedentary behaviour (SB) and physical activity (PA) have been shown to be associated with depression. However, behaviours, such as PA, occupy a portion of an individual's 24-h day. Thus, an increase in time for one behaviour takes away time from another. Previous evidence suggests that it would be more appropriate to shift the focus to the importance of reallocating time spent in sedentary behaviour to time spent in physical activity. The aim of this study was to analyse the mutual replacement effect of different health behaviours on depressive tendencies by isotemporal substitution modelling (ISM) under the objective condition of considering a limited 24-h day. Second, we aimed to further explore the potential association between excessive or insufficient sleep duration and depressive symptoms.

METHODS

A total of 10656 employees from 79 companies in four provinces of China participated in this survey. The Center for Epidemiological Studies Depression Scale (CES-D) was used to measure workers' depressive tendencies. The duration of various types of physical activity was self-reported by workers based on the International Physical Activity Questionnaire (IPAQ). ISM was used to assess the associations of time spent in different activities on displacement of equivalent time spent on other activities with depression risk.

RESULTS

A total of 10656 participants (89.5% of the sample) were included in the analysis. The ISM found that a 30-min unit of SB replaced with walking (OR, 95% CI: 0.83, 0.77-0.88), sleep (≤ 8 h) (OR, 95% CI: 0.77, 0.74-0.79), moderate physical activity (MPA) (OR, 95% CI: 0.87, 0.81-0.93) and vigorous physical activity (VPA) (OR, 95% CI: 0.91, 0.84-0.99) was significantly and negatively associated with the risk of depressive tendencies. When sleep duration was less than 8 h, each additional half hour of sleep time was significantly associated with a lower risk of depressive tendencies, and this association was no longer significant after 8 h.

CONCLUSION

Prolonged SB is common in the current workplace in China. Replacing an average of 30 min per day of SB with VPA and MPA, even walking is associated with less depression among workers. In addition, insufficient daily sleep is also an important risk factor for workers' depressive tendencies. These findings provide valuable evidence to promote mental health among occupational groups and support the development of healthy workplaces.

Moving beyond moderate-to-vigorous physical activity: the role of light physical activity during adolescence

Regular physical activity is an important component of a healthy lifestyle for young people. However, an estimated 80% of adolescents globally are insufficiently active. Traditionally, health benefits were attributed only to physical activity of at least moderate intensity, and recommendations focused on achieving a threshold of moderate-to-vigorous physical activity, without consideration of other aspects of movement within the 24 h cycle. Recently, the overall daily balance of active and sedentary behaviours has gained recognition as an important determinant of health. However, the relationship between light intensity physical activity and health has not been fully explored. In this perspective paper, we discuss key challenges in defining, measuring and analysing light physical activity which have hindered the advancement of knowledge in this area. Next, we suggest three ways in which light physical activity may enhance adolescent wellbeing: firstly, by replacing sedentary behaviours to increase daily movement; secondly, by supporting the accumulation of higher intensities of physical activity; and thirdly, by providing positive experiences to facilitate lifelong engagement with physical activity. In highlighting the importance of light physical activity during adolescence, we aim to encourage critical reflection and the exploration of new approaches towards physical activity within public health and beyond.

Association between physical activity and depressive symptoms in adolescents: A prospective cohort study

It remains uncertain whether a protective association between physical activity and depression exists among adolescents and what the optimal level of physical activity might be. This study aimed to estimate the associations of physical activity levels with depressive symptoms and new-onset depression, while identifying potential modifying factors influencing the relationships. In this cohort study, we initially enrolled 1957 participants at baseline and followed up with 1738 of them after two years. Our analysis focused on data from 1482 students who provided complete information on both physical activity and depressive symptoms. Generalized linear regression and restricted cubic spline regression models were performed. Our adjusted models revealed that engaging in 4-7 h/week of moderate-to-vigorous physical activity (MVPA) at baseline was negatively associated with subsequent depressive symptoms and new-onset depression compared to the non-MVPA group. However, exceeding 7 h/week of MVPA did not provide substantial benefits. Furthermore, drinking and screen time potentially modified the relationship between MVPA and new-onset depression. Our findings suggest that 4-7 h of MVPA per week may be an appropriate level to reduce depressive symptoms in adolescents. Moreover, individual behaviors (e.g., drinking and screen time) warrant heightened attention in interventions targeting the reduction of depression in this population.

The association between reallocations of time and health using compositional data analysis: a systematic scoping review with an interactive data exploration interface

BACKGROUND

How time is allocated influences health. However, any increase in time allocated to one behaviour must be offset by a decrease in others. Recently, studies have used compositional data analysis (CoDA) to estimate the associations with health when reallocating time between different behaviours. The aim of this scoping review was to provide an overview of studies that have used CoDA to model how reallocating time between different time-use components is associated with health.

METHODS

A systematic search of four electronic databases (MEDLINE, Embase, Scopus, SPORTDiscus) was conducted in October 2022. Studies were eligible if they used CoDA to examine the associations of time reallocations and health. Reallocations were considered between movement behaviours (sedentary behaviour (SB), light physical activity (LPA), moderate-to-vigorous physical activity (MVPA)) or various activities of daily living (screen time, work, household chores etc.). The review considered all populations, including clinical populations, as well as all health-related outcomes.

RESULTS

One hundred and three studies were included. Adiposity was the most commonly studied health outcome (n = 41). Most studies (n = 75) reported reallocations amongst daily sleep, SB, LPA and MVPA. While other studies reported reallocations amongst sub-compositions of these (work MVPA vs. leisure MVPA), activity types determined by recall (screen time, household chores, passive transport etc.) or bouted behaviours (short vs. long bouts of SB). In general, when considering cross-sectional results, reallocating time to MVPA from any behaviour(s) was favourably associated with health and reallocating time away from MVPA to any behaviour(s) was unfavourably associated with health. Some beneficial associations were seen when reallocating time from SB to both LPA and sleep; however, the strength of the association was much lower than for any reallocations involving MVPA. However, there were many null findings. Notably, most of the longitudinal studies found no associations between reallocations of time and health. Some evidence also suggested the context of behaviours was important, with reallocations of leisure time toward MVPA having a stronger favourable association for health than reallocating work time towards MVPA.

CONCLUSIONS

Evidence suggests that reallocating time towards MVPA from any behaviour(s) has the strongest favourable association with health, and reallocating time away from MVPA toward any behaviour(s) has the strongest unfavourable association with health. Future studies should use longitudinal and experimental study designs, and for a wider range of outcomes.

24-hour movement behaviours and self-rated health in Chinese adolescents: a questionnaire-based survey in Eastern China

Objective

Although much evidence has demonstrated the benefits of adhering to the 24-hour movement guidelines, little is known about their association with self-rated health in adolescents. The objective of this study was to explore the association between adherence to the 24-hour movement guidelines (i.e., physical activity, screen time, and sleep) and self-rated health among Chinese adolescents aged 10-17 ages.

Methods

A convenient sample of 12 schools and their students were recruited for this cross-sectional study. Physical activity and screen time were assessed using a questionnaire based on the Health Behaviour in School-aged Children questionnaire, while sleep duration was used measured using the Pittsburgh Sleep Scale. Ordinal logistic regression was performed to examine the association between adherence to the 24-hour movement guidelines and self-rated health.

Results

Adolescents who adhered to more guidelines contained in the 24-hour movement guidelines reported better self-rated health. A dose-response association was observed, with the odds ratio (OR) for adhering to all three = 11.26, 95% CI [4.82-26.35]; OR for meeting two = 1.62, 95% CI [1.25-2.12]; OR for meeting one = 1.16, 95% CI [0.98-1.38]) indicating a higher probability of better self-rated health with increasing adherence. Regarding adherence to specific combination of 24-hour movement guidelines, positive associations were found for adhering to all three recommendations (OR = 11.95, 95% CI [5.06-28.19]), only MVPA (OR = 4.96, 95% CI [2.82-8.72]), MVPA + screen time (OR = 5.50, 95% CI [3.02-9.99]), and MVPA + sleep (OR = 4.63, 95% CI [2.52-8.51]).

Conclusion

This study provides evidence supporting the association between adherence to the 24-hour movement guidelines and better self-rated health among Chinese adolescents. Sufficient physical activity may be particularly important for promoting self-rated health in this population.

Physical activity during early life and the risk of all-cause mortality in midlife: findings from a birth cohort study

BACKGROUND

The objective of this study was to examine the association between physical activity during childhood and adolescence and the risk of all-cause mortality in midlife. We analyzed data from a birth cohort (The 1958 National Child Development Survey), including births in England, Wales and Scotland.

METHODS

Physical activity was assessed using questionnaires at ages 7, 11 and 16. Death certificates defined all-cause mortality. Cumulative exposure, sensitive and critical periods, and physical activity trajectory from childhood to adolescence were tested using multivariate Cox proportional hazard models. The sweep the death was confirmed was defined as the time event.

RESULTS

From age 23 to 55, 8.9% of participants (n = 9398) died. Physical activity in childhood and adolescence affected the risk of all-cause mortality in midlife. In men, physical activity at ages 11 [hazard ratio (HR): 0.77; 95% confidence interval (CI): 0.60-0.98] and 16 (HR: 0.60; 95% CI: 0.46-0.78) was associated with reduced risk of all-cause mortality. In women, physical activity at age 16 (HR: 0.68; 95% CI: 0.48-0.95) was associated with reduced risk of all-cause mortality. Physical activity in adolescence eliminated the risk of all-cause mortality associated with physical inactivity in adulthood in women.

CONCLUSIONS

Physical activity during childhood and adolescence was associated with reduced risk of all-cause mortality with different effects by sex.

Prospective association between 24-hour movement behaviors and mental health among overweight/obese college students: a compositional data analysis approach

Background

24-h movement behaviors, including light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), screen-based sedentary behavior (SSB), non-screen-based sedentary behavior (NSB) and sleep are crucial components affecting mental health. This study aimed to examine the associations of movement behaviors with mental health outcomes among overweight/obese college students using a compositional data analysis approach.

Methods

Using a prospective design, 437 Chinese college students (20.1 ± 1.7 years, 51.7% female) completed a two-wave online data collection, where demographics and movement behaviors (LPA, MVPA, SSB, NSB, sleep) were collected at baseline, while depression, anxiety and stress were measured at the 2-month follow-up (Apr-Jul 2022). Compositional data analyses were implemented using R.

Results

Depression, anxiety, and stress were negatively associated with time spent in MVPA and sleep (p < 0.001) and positively associated with time spent in SSB and NSB (p < 0.001). Reallocating 15 min to MVPA from LPA, SSB and NSB predicted improvements in depression (LPA: -0.234 unit; SSB: -0.375 unit; NSB: -0.249 unit), anxiety (LPA: -0.092 unit; SSB: -0.284 unit; NSB: -0.165 unit), and stress (LPA: -0.083 unit; SSB: -0.312 unit; NSB: -0.191 unit). For dose-response relationships of 5-55 min isotemporal substitution, when time was reallocated to MVPA from LPA, NSB, and SSB, the estimated detriments to mental health were larger in magnitude than the estimated benefits of time reallocation from MVPA to LPA, NSB, and SSB.

Conclusion

The findings emphasize the importance of participating in MVPA to improve mental health in overweight/obese college students during the post-COVID-19 era. The compositional analysis produced clear targets for the time allocation of these behaviors for future interventions and policymaking.

Modifications of 24-h movement behaviors to prevent obesity in retirement: a natural experiment using compositional data analysis

BACKGROUND

Retirement often leads to a more passive lifestyle and may therefore lead to weight gain. This study aims to investigate longitudinal associations between changes in 24-h movement behaviors and BMI and waist circumference in relation to the transition from work to retirement.

METHODS

The study population included 213 retiring public sector workers (mean age 63.5 years, standard deviation 1.1) from the Finnish Retirement and Aging study. Before and after retirement participants wore an Axivity accelerometer on their thigh and filled in a daily log for at least four days to measure daily time spent sleeping, in sedentary behavior (SED), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA). Also, their body mass index (BMI) and waist circumference were measured repeatedly. Compositional linear regression analysis and isotemporal substitution analysis were used to study associations between one-year changes in 24-h movement behaviors and concurrent changes in BMI and waist circumference.

RESULTS

An increase in MVPA in relation to sleep, SED and LPA was associated with a decreasing BMI (β = -0.60, p = 0.04) and waist circumference (β = -2.14, p = 0.05) over one year from before retirement to after retirement. In contrast, increasing sleep in relation to SED, LPA and MVPA was associated with an increasing BMI (β = 1.34, p = 0.02). Reallocating 60 min from MVPA to SED or sleep was estimated to increase BMI by on average 0.8-0.9 kg/m2 and waist circumference by 3.0 cm during one year.

CONCLUSIONS

During the transition from work to retirement, increasing MVPA was associated with a slight decrease in BMI and waist circumference, whereas increasing sleep was associated with an increasing BMI. Common life transitions, like retirement, should be considered when giving recommendations and guidance for physical activity and sleep.

Compositional functional regression and isotemporal substitution analysis: Methods and application in time-use epidemiology

The distribution of time that people spend in physical activity of various intensities has important health implications. Physical activity (commonly categorised by the intensity into light, moderate and vigorous physical activity), sedentary behaviour and sleep, should not be analysed separately, because they are parts of a time-use composition with a natural constraint of 24 h/day. To find out how are relative reallocations of time between physical activity of various intensities associated with health, herewith we describe compositional scalar-on-function regression and a newly developed compositional functional isotemporal substitution analysis. Physical activity intensity data can be considered as probability density functions, which better reflects the continuous character of their measurement using accelerometers. These probability density functions are characterised by specific properties, such as scale invariance and relative scale, and they are geometrically represented using Bayes spaces with the Hilbert space structure. This makes possible to process them using standard methods of functional data analysis in the L 2 space, via centred logratio (clr) transformation. The scalar-on-function regression with clr transformation of the explanatory probability density functions and compositional functional isotemporal substitution analysis were applied to a dataset from a cross-sectional study on adiposity conducted among school-aged children in the Czech Republic. Theoretical reallocations of time to physical activity of higher intensities were found to be associated with larger and more progressive expected decreases in adiposity. We obtained a detailed insight into the dose-response relationship between physical activity intensity and adiposity, which was enabled by using the compositional functional approach.

The Goldilocks Day for healthy adiposity measures among children and adolescents

Background

The optimal balance of time spent on daily movement behaviors ("The Goldilocks Day") associated with childhood obesity remains unknown.

Objective

To estimate the optimal durations of sleep, sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MPVA) associated with excess adiposity in a paediatric population.

Methods

Accelerometer-measured 24-h movement behaviors were obtained from 659 Czech children and adolescents (8-18-year-olds). Adiposity indicators were body mass index z-score, fat mass percentage, fat-free mass index, and visceral adipose tissue. Excess adiposity was defined as exceeding the 85th percentile for an adiposity indicator. Compositional regression analyses were used investigate the associations between movement behaviors and adiposity indicators and estimating "The Goldilocks Day."

Results

The movement behavior composition was associated with visceral adipose tissue (Fdf1 = 3,df2 = 317 = 3.672, p = 0.013) and fat mass percentage (Fdf1 = 3,df2 = 289 = 2.733, p = 0.044) among children and adolescents. The Goldilocks Day consisted of 8.5 h of sleep, 10.8 h of SB, 3.9 h of LPA, and 0.8 h of MVPA among children and 7.5 h of sleep, 12.4 h of SB, 3.6 h of LPA, and 0.5 h of MVPA among adolescents.

Conclusion

Optimizing the time spent sleeping, and in sedentary and physical activities appears to be important in the prevention of excess adiposity.

The dilemma of physical activity questionnaires: Fitter people are less prone to over reporting

Physical activity questionnaires (PAQs) are a popular method of monitoring physical activity, although their validity is usually low. Descriptions of physical activity levels in questionnaires usually rely on physical responses to physical activity. Therefore, we hypothesised that the validity of PAQs would be higher in the more physically fit group of participants. To test this, we conducted a validation study with 179 adults whom we divided into three fitness groups based on their cardiovascular fitness and age. Participants were measured for one week using the UKK RM42 accelerometer and self-reported their physical activity using IPAQ-SF, GPAQ, and EHIS-PAQ. We analysed the differences between fitness groups in terms of validity for each PAQ using ANOVA. We also performed an equivalence testing to compare the data obtained with the PAQs and the accelerometers. The results showed a significant trend toward higher validity for moderate to vigorous physical activity from the low to high fitness group as assessed by GPAQ and IPAQ-SF (low, intermediate and high fitness group: 0.06-0.21; 0.26-0.29; 0.40, respectively). The equivalence testing showed that all fitness groups overestimated their physical activity and underestimated their sedentary behaviour, with the high fitness group overestimating their physical activity the least. However, EHIS-PAQ was found to agree best with accelerometer data in assessing moderate to vigorous physical activity, regardless of fitness group, and had a validity greater than 0.4 for all fitness groups. In conclusion, we confirmed that when using PAQs describing physical responses to physical activity, participants' fitness should be considered in the interpretation, especially when comparing results internationally.

Web-based need-supportive parenting program to promote physical activity in secondary school students: a randomized controlled pilot trial

BACKGROUND

Current global trend of insufficient physical activity (PA) among children and adolescents highlights the necessity of finding effective ways to promote PA in childhood. Self-determination theory (SDT) has demonstrated efficacy as a conceptual framework for developing interventions aimed at promoting diverse health behaviours. Parents have potential to influence children's health behaviours to a great extent, which could be enhanced from an online, self-paced training to gain knowledge on how to support children's intrinsic motivation towards particular health behaviour. In this pilot study, we developed and tested an online SDT-informed need-supportive training for parents, enabling them to interact with their children in a way to support their intrinsic motivation towards leisure-time physical activity.

METHODS

Sixty eight students (Mage = 12.5 ± 0.72) and one parent for each child were randomly assigned to the 6-week intervention condition or control condition. Students completed psychological measures (i.e., perceptions of parents' need-supportive behaviours, basic psychological need satisfaction and frustration, autonomous and controlled forms of motivation, as well as social cognition beliefs towards leisure-time PA) and self-reported PA pre-intervention, post-intervention, and one-month after the intervention. Repeated measures ANOVAs were conducted to test the effects of the intervention condition and time.

RESULTS

While a statistically significant intervention effect on children's leisure-time PA was not found, students in the intervention group reported higher, albeit marginal, perceptions of intrinsic motivation (F(2, 84) = 3.095, p = 0.050) and lower perceptions of introjected regulation (F(2, 88) = 3.107, p = 0.050) and autonomy frustration (F(2, 84) = 2.987, p = 0.056) at follow-up. Contrary to expectations, children in the control group demonstrated higher perceptions of intention (F(2, 84) = 4.838, p = 0.010) and effort (F(2, 80) = 3.473, p = 0.036) towards leisure-time physical activity at follow-up. No significant changes were found in perceptions of need-supportive behaviour from parents, attitude, and perceived behavioural control.

CONCLUSIONS

Our pilot study highlights the importance of parental training and the potential for SDT-informed interventions to support children's intrinsic motivation towards physical activity. Further research is needed to test the intervention in other domains and combine interventions in several domains to have the highest impact.

TRIAL REGISTRATION

This pilot study is part of preparation for the main study, prospectively registered in ISRCTN registry as ISRCTN78373974 (15.12.2022). The current stage of the main study is 'recruiting'.

Prehospital Emergency Care in Low- and Middle-Income Countries: A Systematic Review

BACKGROUND

An under-developed and fragmented prehospital Emergency Medical Services (EMS) system is a major obstacle to the timely care of emergency patients. Insufficient emphasis on prehospital emergency systems in low- and middle-income countries (LMICs) currently causes a substantial number of avoidable deaths from time-sensitive illnesses, highlighting a critical need for improved prehospital emergency care systems. Therefore, this systematic review aimed to assess the prehospital emergency care services across LMICs.

METHODS

This systematic review used four electronic databases, namely: PubMed/MEDLINE, CINAHL, EMBASE, and SCOPUS, to search for published reports on prehospital emergency medical care in LMICs. Only peer-reviewed studies published in English language from January 1, 2010 through November 1, 2022 were included in the review. The Newcastle-Ottawa Scale (NOS) and Critical Appraisal Skills Programme (CASP) checklist were used to assess the methodological quality of the included studies. Further, the protocol of this systematic review has been registered on the International Prospective Register of Systematic Reviews (PROSPERO) database (Ref: CRD42022371936) and has been conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Of the 4,909 identified studies, a total of 87 studies met the inclusion criteria and were therefore included in the review. Prehospital emergency care structure, transport care, prehospital times, health outcomes, quality of information exchange, and patient satisfaction were the most reported outcomes in the considered studies.

CONCLUSIONS

The prehospital care system in LMICs is fragmented and uncoordinated, lacking trained medical personnel and first responders, inadequate basic materials, and substandard infrastructure.

The link between unhealthy lifestyle behaviors and emotional and behavioral problems in children and adolescents: a latent class analysis

Unhealthy lifestyle behaviors (ULBs) in children and adolescents are relatively common. Previous studies have shown an association between a single ULBs and emotional and behavioral problems (EBPs); however, few studies have explored the connection between multiple behavioral patterns and EBPs in children and adolescents. Hence, we aimed to investigate the link between ULBs clusters and EBPs among Chinese children and adolescents. From April to May 2019, we used cluster sampling to investigate children and adolescents in grades 1-12 from 14 schools located across six streets of Bao'an District in the city of Shenzhen. We measured emotional and behavioral problems using the Strengths and Difficulties Questionnaire (SDQ). ULBs included the consumption of sugar-sweetened beverages, takeaway and fast food consumption, lack of sleep, low outdoor activity, and excessive screen time. We performed clustering of ULBs using the regression hybrid modeling method of latent class analysis (LCA). We analyzed the association between ULBs and EBPs using logistic regression. In total, 30188 children and adolescents remained for analysis, with an average age of 12.44 ± 3.47 years. The LCA revealed four distinct patterns of ULBs: (1) lowest risk; (2) high-risk unhealthy lifestyle behaviors; (3) high-risk dietary unhealthy lifestyle behaviors; and (4) highest risk. Compared to ULBs with the lowest risk, high-risk ULBs, high-risk dietary ULBs, and highest risk ULBs were positively correlated with EBPs, with an adjusted odds ratio (aOR) (95% confidence interval [CI]) of 1.27, 1.34 and 2.05, respectively. Children and adolescents who reported engaging in multiple ULBs were also more likely to have poorer EBPs status. This implies that school administrations should pay more attention to the management of dietary and lifestyle behaviors to prevent EBPs in children and adolescents. Our findings highlight the need to focus on multiple clusters of ULBs among adolescents in a preventive care system and to validate EBP that may occur in children who are exposed to ULBs.

Association of Domains of Sedentary Behavior with Cardiovascular Disease Events in The Multi-Ethnic Study of Atherosclerosis

Background

Sedentary behavior is associated with an increased risk for adverse health outcomes, including cardiovascular disease (CVD), independent of physical activity status. Little is known about this relationship in an ethnically diverse population. The objective of our study is to assess the effects of leisure time and occupational sedentary behavior on multiple cardiovascular outcomes in a multi-ethnic cohort.

Methods

The Multi-Ethnic Study of Atherosclerosis (MESA) includes 2619 Caucasian, 1495 Hispanic, 1891 Black, and 804 Chinese-American adults aged 45-84 years and free of clinical CVD at enrollment, Sedentary behavior was self-reported at baseline. Participants were followed for an average of 13.6 years, and 14 types of cardiovascular outcomes were ascertained. Hazards of each cardiovascular outcome were modeled with adjustment for potential confounders, including physical activity.

Results

Every one hour per day increase in leisure time sedentary behavior predicts a 6% increase in the adjusted hazards for CVD death ( P < 0.05). Every one hour increase in occupational sedentary time predicts a 21% and 20% decrease in the hazard for PVD and other revascularization, respectively ( P < 0.05).

Conclusions

Leisure time sedentary behavior was associated with increased hazards for CVD death, but occupational sedentary time appears to be protective of peripheral vascular disease and other revascularization.

Condensed Abstract

Sedentary behavior has been consistently associated with an increased risk for adverse health outcomes, including cardiovascular disease (CVD), independent of physical activity status. The Multi-Ethnic Study of Atherosclerosis (MESA) consists of a racially and ethnically diverse cohort of adults age 45-84, free from CVD at baseline. Greater levels of leisure time sedentary behavior predicted increased hazards for PVD and CVD death after an average follow up of 13.6 years whereas occupational sedentary behaviors predicted reduced PVD. These results underscore the importance of reducing time spent sitting in addition to advocating for meeting physical activity targets across ethnicities.

Physical Activity of Children and Adolescents in Croatia: A Global Matrix 4.0 Systematic Review of Its Prevalence and Associated Personal, Social, Environmental, and Policy Factors

BACKGROUND

The previous review of physical activity (PA) among Croatian children and adolescents was conducted a decade ago. Therefore, the aim of this study was to summarize recent evidence on PA of Croatian children and adolescents and associated personal, social, environmental, and policy factors.

METHODS

Eighteen experts reviewed the available evidence and provided ratings (from the lowest grade "F" to the highest grade "A+") for the 10 Global Matrix indicators. A systematic search with 100 keywords was conducted in Hrčak, PubMed/MEDLINE, Scopus, SPORTDiscus, and Web of Science for documents published from January 01, 2012, to April 15, 2022. We also conducted internet searches and secondary analyses of data (relative frequencies) from 6 studies.

RESULTS

After assessing 7562 references, we included 90 publications in the review and 18 studies (83.3% of medium-to-good quality) in evidence synthesis. We found a high prevalence of insufficient PA (especially among girls) and excessive screen time (especially among boys). PA participation of children and adolescents in Croatia has declined over time. The following grades were assigned to the indicators for Croatia: B- for overall PA, C- for organized sport and PA, C for active play, C- for active transportation, D+ for sedentary behavior, inconclusive for physical fitness, D+ for family and peers, B- for school, B- for community and environment, and D+ for government.

CONCLUSIONS

Coordinated actions are needed across sectors to improve PA promotion, with a focus on increasing PA among girls, reducing sedentary screen time among boys, improving parental support for PA, and further development of national PA policies.

Defecation Habits in Preschoolers Are Associated with Physical Activity: A Cross-Sectional and Isotemporal Substitution Analysis

There is a lack of research on the relationship between defecation habits (DF) and physical activity (PA) in preschoolers. This study aimed to clarify the relationship between sedentary behaviour (SB), PA time, and DF in preschoolers and to estimate the effect of DF replacement in an isotemporal substitution (IS) model. The participants included 166 children (aged 4-6 years) attending childcare facilities. PA was measured using an accelerometer to calculate the daily activity and wearing time for SB, light-intensity physical activity (LPA), and moderate-to-vigorous-intensity physical activity (MVPA). DF were classified based on defecation frequency and timing. A multinomial logistic regression analysis was used for the IS model. One-way analysis of variance detected significant differences in MVPA between the DF groups (F(2) = 3.12, p < 0.05). According to the analysis results of the IS model, replacing 5 min of SB with MVPA resulted in improved DF (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.81-0.97). Conversely, replacing 5 min of MVPA with SB worsened DF (OR, 1.13; 95% CI, 1.03-1.23). The findings suggest that PA is associated with DF among preschoolers. It also indicates that replacing SB with MVPA could help improve DF in children.

Sleep Quality, Metabolic Function, Physical Activity, and Neurocognition Among Individuals with Resistant Hypertension

BACKGROUND

Resistant hypertension (RH) is a major risk factor for stroke, cognitive decline, and dementia. Sleep quality is increasingly suggested to play an important role linking RH to cognitive outcomes, although the mechanisms linking sleep quality to poor cognitive function have yet to be fully delineated.

OBJECTIVE

To delineate biobehavioral mechanisms linking sleep quality, metabolic function, and cognitive function among 140 overweight/obese adults with RH in the TRIUMPH clinical trial.

METHODS

Sleep quality was indexed using actigraphy measures of sleep quality and sleep fragmentation, as well as self-reported sleep quality from the Pittsburgh Sleep Quality Index (PSQI). Cognitive function was assessed using a 45-minute battery assessing executive function, processing speed, and memory. Participants were randomized to a cardiac rehabilitation-based lifestyle program (C-LIFE) or a standardized education and physician advice condition (SEPA) for 4 months.

RESULTS

Better sleep quality at baseline was associated with better executive function (B = 0.18 p = 0.027), as well as greater fitness (B = 0.27, p = 0.007) and lower HBA1c (B = -0.25, p = 0.010). Cross-sectional analyses revealed that the sleep quality executive function association was mediated by HBA1c (B = 0.71 [0.05, 2.05]). C-LIFE improved sleep quality (-1.1 [-1.5, -0.6] versus+-0.1 [-0.8, 0.7]) and actigraphy steps (+922 [529, 1316] versus+56 [-548, 661]), with actigraphy mediating improvements in executive function (B = 0.40 [0.02, 1.07]).

CONCLUSION

Better metabolic function and improved physical activity patterns levels play important roles linking sleep quality and executive function in RH.

Survey of the Adequacy of Brazilian Children and Adolescents to the 24-Hour Movement Guidelines before and during the COVID-19 Pandemic

The 24-Hour Movement Guidelines provide specific recommendations on movement behaviors for children and adolescents. The objective of this study was to verify the adequacy of children and adolescents to the guidelines for moderate to vigorous physical activity, recreational screen time, and sleep duration, and the overall adequacy to the guidelines, before and during the COVID-19 pandemic. A cross-sectional study was conducted with parents or guardians of children or adolescents from different regions of Brazil using a digital interview form including sociodemographic characteristics of families, moderate to vigorous physical activity, recreational screen time, and sleep duration before and during the pandemic. Statistically significant variation was observed in both groups in relation to moderate to vigorous physical activity and recreational screen time between the two periods evaluated. Overall adequacy to the guidelines before the pandemic was 19.28% for children from Group 1 (0-5 years old) and 39.50% for those from Group 2 (6 to 17 years old). During the pandemic, it corresponded to 3.58% in Group 1 and 4.94% in Group 2 (p-value between periods ≤0.001). This study showed the significant impact of pandemic restrictions on reducing overall compliance and physical activity, and increasing screen time among Brazilian children and adolescents.

Exchanging screen for non-screen sitting time or physical activity might attenuate depression and anxiety: A cross-sectional isotemporal analysis during early pandemics in South America

OBJECTIVES

To examine the theoretical substitutions of screen exposure, non-screen sitting time, moderate and vigorous physical activity with depressive and anxiety symptoms in South American adults during the COVID-19 pandemic.

DESIGN

A cross-sectional study during the first months of the COVID-19 pandemic with data from 1981 adults from Chile, Argentina, and Brazil.

METHODS

Depressive and anxiety symptoms were assessed using the Beck Depression and Anxiety Inventories. Participants also reported physical activity, sitting time, screen exposure, sociodemographic, and tobacco use data. Isotemporal substitution models were created using multivariable linear regression methods.

RESULTS

Vigorous physical activity, moderate physical activity, and screen exposure were independently associated with depression and anxiety symptoms. In adjusted isotemporal substitution models, replacing 10 min/day of either screen exposure or non-screen sitting time with any intensity of physical activity was associated with lower levels of depressive symptoms. Improvements in anxiety symptoms were found when reallocating either screen exposure or non-screen sitting time to moderate physical activity. Furthermore, replacing 10 min/day of screen exposure with non-screen sitting time was beneficially associated with anxiety (B = -0.033; 95 % CI = -0.059, -0.006) and depression (B = -0.026; 95 % CI = -0.050, -0.002).

CONCLUSIONS

Replacement of screen exposure with any intensity of physical activity or non-screen sitting time could improve mental health symptoms. Strategies aiming to reduce depressive and anxiety symptoms highlight physical activity promotion. However, future interventions should explore specific sedentary behaviors as some will relate positively while others negatively.