Associations of objectively assessed physical activity and sedentary time with all-cause mortality in US adults: the NHANES study

Development of an accelerometer age- and sex-specific approach based on population-standardized values for physical activity surveillance: A proof of concept

BACKGROUND

A shift from self-reports to wearable sensors for global physical activity (PA) surveillance has been recommended. The conventional use of a generic cut-point to assess moderate-to-vigorous PA (MVPA) is problematic as these cut-points are often derived from non-representative samples under non-ecological laboratory conditions. This study aimed to develop age- and sex-specific (age-sex) cut-points for MVPA based on population-standardized values as a feasible approach to assess the adherence to PA guidelines and to investigate its associations with all-cause mortality.

METHODS

A total of 7601 participants (20-85+ years) were drawn from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Surveys (NHANES). Minutes per week of MVPA were assessed with a hip-worn accelerometer. Counts per minute (CPM) were used to define an age- and sex-specific target intensity, representing the intensity each person should be able to reach based on their age and sex. Age- and sex-specific MVPA cut-points were defined as any activity above 40% of the target intensity. These population- and free-living-based age-sex specific cut-points overcome many of the limitations of the standard generic cut-point approach. For comparison, we also calculated MVPA with a generic cut-point of 1952 CPM. Both approaches were compared for assessing adherence to PA guidelines and association of MVPA with all-cause mortality (ascertained through December 2015).

RESULTS

Both approaches indicated that 37% of the sample met the 150+ min/week guideline. The generic cut-point approach showed a trend to inactivity with age, which was less pronounced using the age-sex cut-points. Overall mortality rates were comparable using generic cut-point (hazard ratio (HR) = 0.61, 95% confidence interval (95%CI): 0.50‒0.73) or age-sex cut-points (HR = 0.57, 95%CI: 0.50‒0.66) for the entire sample. The generic cut-point method revealed an age- and sex-related gap in the benefits of achieving 150+ min/week of MVPA, with older adults showing an 18% greater reduction in mortality rates than younger adults, and a larger difference in women than in men. This disparity disappeared when using age-sex-specific cut-points.

CONCLUSION

Our findings underscore the value of age-sex cut-points for global PA surveillance. MVPA defined with age-sex thresholds was associated with all-cause mortality and the dose‒response was similar for all ages and sexes. This aligns with the single recommendation of accumulating 150+ min/week MVPA for all adults, irrespective of age and sex. This study serves as a proof of concept to develop this methodology for PA surveillance over more advanced open-source acceleration metrics and other national and international cohorts.

Exploring the Association between Daily Distributional Patterns of Physical Activity and Cardiovascular Mortality Risk among Older Adults in NHANES 2003-2006

PURPOSE

Cardiovascular disease (CVD) is one of the leading causes of death worldwide. Physical activity (PA) has previously been shown to be a prominent risk factor for CVD mortality. Traditionally, measurements of PA have been self-reported and based on various summary metrics. However, recent advances in wearable technology provide continuously monitored and objectively measured physical activity data. This facilitates a more comprehensive interpretation of the implications of PA in the context of CVD mortality by considering its daily patterns and compositions.

METHODS

This study utilized accelerometer data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) on 2,816 older adults aged 50-85 and mortality data from the National Death Index (NDI) in December 2019. A novel partially functional distributional analysis method was used to quantify and understand the association between daily distributional patterns of physical activity and cardiovascular mortality risk through a multivariable functional Cox model.

RESULTS

A higher mean intensity of daily PA during the day was associated with a reduced hazard of CVD mortality after adjusting for other higher order distributional summaries of PA and age, gender, race, body mass index (BMI), smoking and coronary heart disease (CHD). A higher daily variability of PA during afternoon was associated with a reduced hazard of CVD mortality, after adjusting for the other predictors, particularly on weekdays. The subjects with a lower variability of PA, despite having same mean PA throughout the day, could have a lower reserve of PA and hence could be at increased risk for CVD mortality.

CONCLUSIONS

Our results demonstrate that not only the mean intensity of daily PA during daytime, but also the variability of PA during afternoon could be an important protective factor against the risk of CVD-mortality. Considering circadian rhythm of PA as well as its daily compositions can be useful for designing time-of-day and intensity-specific PA interventions to protect against the risk of CVD mortality.

Enhancing mental well-being of undergraduates: establishing cut-off values and analyzing substitutive effects of physical activity on depression regulation

Objective

This study aimed to analyze the effects of physical activity (PA), sleep quality, and sedentary behavior on subthreshold depression (StD) among undergraduates.

Methods

This study included 834 undergraduates and assessed the impact of PA time, sleep quality, and sedentary behavior on depression. The receiver operating characteristic (ROC) analysis was performed to determine cut-off values for StD risk, while the isochronous substitution analysis was performed to evaluate the effects of different activities on depression regulation.

Results

Gender, age, and academic grade had no significant influence on depression levels among undergraduates (p > 0.05). However, students engaging in sedentary behavior for more than 12.1 h per day or with a Pittsburgh Sleep Quality Index score above 3.5 were at an increased risk of subclinical depression. Additionally, the isochronous substitution of light-intensity physical activity for other activities (sleep, sedentary behavior, moderate and vigorous intensity physical activity) showed statistically significant effects (p < 0.05) in both 5-min and 10-min substitution models, demonstrating a positive effect on alleviating depression.

Conclusion

The findings indicate that specific lifestyle factors, particularly high levels of sedentary behavior and poor sleep quality, are crucial determinants of subclinical depression among undergraduates, independent of demographic variables such as gender, age, and academic grade. Notably, light-intensity PA plays a key role in StD regulation, as substituting it with more intense physical activities or improving sleep quality substantially reduces depression scores. Furthermore, the benefits such substitution became more pronounced with the increase in duration of the activity.

Delay Discounting and BMI in Hypertensives: Serial Mediations of Self-Efficacy, Physical Activity and Sedentary Behavior

Objective

Our study aimed to examine the association between delay discounting (DD) and body mass index (BMI) in individuals with hypertension. Additionally, we sought to explore and compare the potential mediating effects of self-efficacy, physical activity and sedentary behavior in this association.

Methods

A cross-sectional survey was conducted in two cities in the Jiangsu province of China, specifically Nanjing and Yangzhou, from March to June 2023. A total of 972 hypertensive patients completed the questionnaire (M age = 64.7 years, SD age = 8.2 years, 54.2% female). Participants engaged in a money choice experiment on computers, provided their height and weight, and completed the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and General Self-Efficacy Scale (GSES). The experimental program was generated using the programming software E-Prime version 2.0. Multiple hierarchical regression analysis was conducted to identify potential covariates. Two serial mediation models were conducted using PROCESS macro 4.1 in SPSS 27.0. Physical activity and sedentary behavior were designated as M2 to investigate and contrast their respective mediating effects in the association between delay discounting and body mass index.

Results

Self-efficacy, physical activity, and sedentary behavior served as mediators in the relationship between delay discounting and BMI. Self-efficacy accounted for 14.9% and 14.3% of the total effect in Models 1 and 2, respectively, while physical activity and sedentary behavior each accounted for 14.9% and 9.5% of the total effect, respectively. The serial mediation effects of self-efficacy and physical activity, as well as self-efficacy and sedentary behavior, were significant (B = 0.01, 95% CI [0.01, 0.02]; B = 0.01, 95% CI [0.002, 0.01]), collectively contributing 2.1% and 2.4% of the total effect. Sedentary behavior played a smaller mediating role compared to physical activity in this association.

Conclusion

The results indicated that self-efficacy, physical activity and sedentary behavior could act as mediators in the association between delay discounting and BMI, thus potentially mitigating the risk of obesity in hypertensive individuals.

Applied Physical Activity Epidemiology: Relationship of Physical Activity and Exercise Exposures with Health Outcomes

There is consistent, strong evidence that both physical activity and exercise lowers risk of many diseases, yet the way physical activity and exercise are measured varies substantially. Physical activity epidemiologists use observational designs (such as cohort or case-control studies) to examine the relationship of physical activity exposures and outcomes including mortality, or disease-specific such as incident type 2 diabetes mellitus, cancer, cardiovascular disease, anxiety, or depression. These same observational designs can be used to examine the associations of prevalent disease in reducing symptom burden in those who are physically active compared to those who are not, specifically examining anxiety and depression. There is great statistical power and often large sample sizes in physical activity epidemiologic studies with valid and reliable assessment tools but known limitations such as measurement error or social desirability bias. Overall, physical activity epidemiology can be a useful tool to understand the influence of exercise and physical activity on risk of disease. In this chapter, we will explore the strength, consistency, and sources of evidence primarily using a physical activity epidemiology lens.

A Physical Activity and Sitting Time Balance Index and All-Cause Mortality Risk

INTRODUCTION

Achieving a healthier balance of more time spent in physical activity (PA) and less time in sedentary behavior is now widely advocated for achieving multiple health benefits. This study introduces a Physical Activity and Sitting Time Balance Index (PASTBI), a potential risk identification tool addressing the interplay between PA and sedentary behavior; and aims to explore its association with the risk of all-cause mortality in Australian adults.

METHODS

This prospective cohort study analyzed the Australian Diabetes, Obesity and Lifestyle Study (AusDiab) data on 5,836 Australian adults. The PASTBI was calculated by dividing the total duration of PA (minutes/day) by the duration of sitting time (ST) (hours/day), both self-reported at baseline (2004-2005). The PASTBI was expressed in quartiles ranging from Q1 - low PA/high ST to Q4 - high PA/low ST. The association between PASTBI and all-cause mortality was explored (in 2022) using the Cox proportional hazards regression models adjusted for socio-demographics, lifestyle factors, waist circumference, and the number of comorbidities.

RESULTS

During 78,406 person-years of follow-up (median follow-up of 14.3 years), there were 885 deaths (15%). In the fully adjusted model, compared to those in the highest PASTBI category (Quartile 4 - high PA/low ST), participants from the lowest PASTBI category (Quartile 1 - low PA/high ST) were at a higher risk of all-cause mortality [HR (95% CI) = 1.47 (1.21-1.79)].

CONCLUSIONS

A less favorable balance of time spent in PA and ST (as characterized by a parsimonious PASTBI index approach) was associated with a higher risk of all-cause mortality.

Quantifying the time-varying association between objectively measured physical activity and mortality in US older adults over a 12-year follow-up period: the NHANES 2003-2006 study

Objectively measuring physical activity (PA) has consistently shown an association with reduced all-cause mortality risk in cross-sectional studies. However, the strength of this association may change over time. We quantify the time-varying, covariate-adjusted association between the total volume of PA and all-cause mortality over a 12-year follow-up period using Cox regression with a time varying effect of population-referenced quantile total activity count adjusted for traditional risk factors. Analyses focus on participants 50-84 years old with adequate accelerometer wear time and without missing covariates. The findings suggest that (1) the use of baseline PA in Cox models with long follow-up periods may be inappropriate without time-varying effects and (2) the use of accelerometry derived volume of PA in risk score calculations may be most appropriate for short-term to medium-term risk scores.

Association of Sedentary Lifestyle with All-Cause and Cause-Specific Mortality in Adults with Reduced Kidney Function

Key Points

Nearly half of individuals with reduced kidney function had sedentary lifestyle, defined as more than 6 hours of sitting a day. Non-Hispanic White individuals and individuals with younger age, obesity, and with diabetes were more likely to have sedentary lifestyles. Spending more than 6 hours a day sedentary increases the future risk of death from all causes and cardiovascular diseases in individuals with reduced kidney function.

Background

Individuals with CKD tend to have sedentary behavior and decreased physical activity; both are independent predictors of mortality in general population. While physical inactivity correlates to adverse health outcomes in patients with reduced kidney function, it is unclear whether this relationship remains significant for sedentary behavior. Our study purpose was to evaluate the association of sedentary lifestyle with mortality risk in individuals with renal insufficiency.

Methods

The study population were adult participants of 2007–2016 National Health and Nutrition Examination Survey with eGFR <60 ml/min per 1.73 m2 or self-reporting receiving dialysis (N =1419). Sedentary lifestyle was defined as sedentary time >6 hours per day. Outcome of interest was all-cause and cardiovascular disease (CVD)–related or cancer-related mortality.

Results

We observed that non-Hispanic White individuals and individuals with younger age and higher educational level were more likely to have sedentary lifestyle. During a median follow-up of 99 (interquartile range, 70–128) months, a total of 458 participants died (3.98 deaths per 1000 person-months); 120 died from CVD and 92 from cancer, respectively. The crude analysis showed that individuals with sedentary lifestyle have higher risk of all-cause and CVD-related but not cancer-related mortality compared with the nonsedentary population. After adjusting for potential confounders, we showed that all-cause mortality and CVD-related mortality were 1.64-fold (95% confidence interval, 1.26 to 2.12) and 1.66-fold (95% confidence interval, 1.03 to 2.67) higher, respectively, in the sedentary population compared with the nonsedentary population. Similar results were observed in the sensitive analyses, in which we excluded individuals with dialysis, eGFR <15 ml/min per 1.73 m2, or mobility disability.

Conclusions

Our findings suggest that sedentary lifestyle correlated to greater risk of all-cause and CVD-related mortality among individuals with reduced kidney function. Interventions targeting the individuals with risky behaviors may have practical importance for public health.

Quantifying the Association between Objectively Measured Physical Activity and Multiple Sclerosis in the UK Biobank

INTRODUCTION

Objectively measured physical activity (PA) data were collected in the accelerometry substudy of the UK Biobank. UK Biobank also contains information about multiple sclerosis (MS) diagnosis at the time of and after PA collection. This study aimed to 1) quantify the difference in PA between prevalent MS cases and matched healthy controls, and 2) evaluate the predictive performance of objective PA measures for incident MS cases.

METHODS

The first analysis compared eight accelerometer-derived PA summaries between MS patients ( N = 316) and matched controls (30 controls for each MS case). The second analysis focused on predicting time to MS diagnosis among participants who were not diagnosed with MS. A total of 19 predictors including eight measures of objective PA were compared using Cox proportional hazards models (number of events = 47; 585,900 person-years of follow-up).

RESULTS

In the prevalent MS study, the difference between MS cases and matched controls was statistically significant for all PA summaries ( P < 0.001). In the incident MS study, the most predictive variable of progression to MS in univariate Cox regression models was lower age ( C = 0.604), and the most predictive PA variable was lower relative amplitude (RA, C = 0.594). A two-stage forward selection using Cox regression resulted in a model with concordance C = 0.693 and four predictors: age ( P = 0.015), stroke ( P = 0.009), Townsend deprivation index ( P = 0.874), and RA ( P = 0.004). A model including age, stroke, and RA had a concordance of C = 0.691.

CONCLUSIONS

Objective PA summaries were significantly different and consistent with lower activity among study participants who had MS at the time of the accelerometry study. Among individuals who did not have MS, younger age, stroke history, and lower RA were significantly associated with a higher risk of a future MS diagnosis.

Objectively Assessing the Effect of a Messenger-based Intervention to Reduce Sedentary Behavior in University Students: A Pilot Study

AIM

Sedentary behavior poses a serious health risk. Students in particular are highly affected by prolonged, uninterrupted periods of sitting due to routines in everyday university life, such as attending lectures, self-study periods in the library, etc. Whereas university students are mostly young and therefore appear to be healthy, evidence-based consequences of prolonged sitting may come to pass in prospective times. Therefore, primary prevention must be initiated to shield university students from the occurrence of non-communicable diseases (NCDs). Consequently, the study aims to evaluate a messenger-based intervention designed to reduce sedentary time among university students.

SUBJECTS AND METHODS

The effectiveness of the intervention was assessed in a randomized controlled trial with a convenience sample of thirty-four German university students. ActivPal devices (Pal Technologies Ltd., Glasgow) were applied to measure sedentary behavior objectively before and after a 3-week intervention of messages to interrupt sedentary time. An additional evaluation of the messages was carried out.

RESULTS

Sedentary behavior decreased by about one hour in the intervention group. Explorative analysis shows a statistically significant, negative correlation between sedentary time at baseline and the change of sedentary behavior over time in the intervention group (r = - .81) indicating effectiveness of the intervention for the participants with the highest sedentary times at baseline. Additionally, the messages were considered appropriate by the participants.

CONCLUSION

A reduction of sedentary time of one hour per day in the intervention group is practically significant. The current investigation had similar findings with prior studies where promising results for the reduction of sedentary behavior were observed through mobile-based interventions. The detected effects of the intervention in this pilot study demonstrate an opportunity for further research in this field.

There is urgent need to treat atherosclerotic cardiovascular disease risk earlier, more intensively, and with greater precision: A review of current practice and recommendations for improved effectiveness

Atherosclerotic cardiovascular disease (ASCVD) is epidemic throughout the world and is etiologic for such acute cardiovascular events as myocardial infarction, ischemic stroke, unstable angina, and death. ASCVD also impacts risk for dementia, chronic kidney disease peripheral arterial disease and mobility, impaired sexual response, and a host of other visceral impairments that adversely impact the quality and rate of progression of aging. The relationship between low-density lipoprotein cholesterol (LDL-C) and risk for ASCVD is one of the most highly established and investigated issues in the entirety of modern medicine. Elevated LDL-C is a necessary condition for atherogenesis induction. Basic scientific investigation, prospective longitudinal cohorts, and randomized clinical trials have all validated this association. Yet despite the enormous number of clinical trials which support the need for reducing the burden of atherogenic lipoprotein in blood, the percentage of high and very high-risk patients who achieve risk stratified LDL-C target reductions is low and has remained low for the last thirty years. Atherosclerosis is a preventable disease. As clinicians, the time has come for us to take primordial and primary prevention more serously. Despite a plethora of therapeutic approaches, the large majority of patients at risk for ASCVD are poorly or inadequately treated, leaving them vulnerable to disease progression, acute cardiovascular events, and poor aging due to loss of function in multiple visceral organs. Herein we discuss the need to greatly intensify efforts to reduce risk, decrease disease burden, and provide more comprehensive and earlier risk assessment to optimally prevent ASCVD and its complications. Evidence is presented to support that treatment should aim for far lower goals in cholesterol management, should take into account many more factors than commonly employed today and should begin significantly earlier in life.

Cardiovascular mortality risk prediction using objectively measured physical activity phenotypes in NHANES 2003-2006

Increased physical activity (PA) has been associated with a decreased risk of cardiovascular disease (CVD) and mortality. However, most previous studies use self-reported PA instead of objectively measured PA assessed by wearable accelerometers. To the best of our knowledge, there have not been studies that quantified the univariate and multivariate ability of objectively measured PA summaries to predict the risk of CVD mortality. We investigate the ability of objectively measured PA summary variables to predict CVD mortality: as individual predictors, as part of the best multivariate model incorporating traditional predictors, and as additions to the best multivariate model using only traditional CVD predictors. Data were collected in the National Health and Nutrition Examination Survey 2003-2006 waves for US participants aged 50-85. The predictive ability was measured using Concordance, sometimes referred to as the C-statistic. Specifically, we calculated 10-fold cross-validated concordance (CVC) in survey-weighted Cox proportional hazard models. The best univariate predictor of CVD mortality was total activity count (outperformed age). In multivariate models, two of the eight predictors identified using the improvement in CVC threshold of 0.001 were PA measures (CVC = 0.844). The best model without physical activity (7 predictors) had CVC of 0.830. The addition of PA measures to the best traditional model was significantly better at predicting CVD mortality (P < 0.001). Accelerometer-derived PA measures have excellent cardiovascular mortality prediction performance. Wearable accelerometers have a potential for assessment of individuals' CVD mortality risks.

Multivariate Analysis on Physical Activity, Emotional and Health Status of University Students Caused by COVID-19 Confinement

Confinement as a result of COVID-19 had a strong impact around the world and restricted mobility. The university community started to take routine classes in a virtual and sedentary way, causing negative effects on their health and habits. The objective of this research is to analyze the impact of confinement through surveys of students and interviews with university professors, in order to study the effects of confinement on physical activity, emotional state, and health. The methodology was as follows: (i) preliminary data; (ii) survey development, interviews, and information collection; (iii) data processing and multivariate presentation of the results, using multiple correspondence analysis (MCA) and multiple factor analysis (MFA). The results of 375 respondents show that there is a low level of physical activity (<300 METs, 49.6%), where women register sedentary behavior (73%). Emotionally, most of them show feeling bored. Some express anxiety, depression, discomfort, and frustration. In terms of health, there are rheumatic, circulatory, respiratory, and other diseases related to obesity. It is essential to create programs that promote physical exercise to reduce the consequences of sedentary lifestyles on the physical, social, and mental health of university students, especially engineering students, who experienced greater effects of confinement than those studying nutrition and social sciences.

Physical Activity and Sedentary Time Among Mothers of School-Aged Children: Differences in Accelerometer-Derived Pattern Metrics by Demographic, Employment, and Household Factors

BACKGROUND

Dynamic patterns of how physical activity and sedentary time are accumulated across the day are associated with health outcomes, independent of total activity levels. Individual factors may influence activity patterns in mothers, but these associations are unknown. This study examined multivariable associations between demographic, employment, and household factors and day-level pattern metrics.

METHODS

Mothers (N = 200) of school-aged children (ages 8-12 years) participated in 6 semi-annual 7-day assessments. Waist-worn Actigraph GT3X accelerometers assessed daily moderate-to-vigorous physical activity (MVPA; minutes, number of short bouts [<10 minutes], proportion of long bouts [≥20 minutes]) and sedentary time (minutes, number of breaks, proportion of long bouts [≥60 minutes], temporal dispersion). Multilevel models examined associations between individual characteristics and activity metrics.

RESULTS

There were 4,930 day-level observations. Having a college degree was associated with fewer short MVPA bouts (B = -2.67), more sedentary minutes (B = 21.66), greater long sedentary bouts (odds ratio = 1.50), and having sedentary time less evenly distributed across the day (B = 0.01). Working full-time was associated with more short MVPA bouts (B = 1.39) and breaks in sedentary time (B = 2.08). Having at least 1 infant (<6 months old) in the same household was associated with fewer MVPA minutes (B = -0.11) and short MVPA bouts (B = -4.46), whereas having at least 1 young child (6 months-5 years old) in the same household was associated with fewer sedentary minutes (B = -11.85) and fewer long sedentary bouts (odds ratio = 0.70).

CONCLUSIONS

Day-level pattern metrics show differences not captured when examining total volume alone. Results provide more nuanced information as to how activity is accumulated in terms of bouts and breaks, which can inform programs to increase MVPA and reduce sedentary time by elucidating subpopulations that should be targeted by health behavior interventions.

Get up, stand up: a randomized controlled trial to assess the effectiveness of a messenger-based intervention to reduce sedentary behavior in university students

Aim

Sedentary behavior is a severe and independent risk factor for health. According to current research, sitting time is at a dangerously high level. Especially young adults show a high prevalence compared to others. The study aimed to assess the effectiveness of a 6-week messenger-based intervention to reduce sedentary behavior in university students.

Subject and methods

The 345 university students that enrolled were randomly assigned to the intervention group (n = 173) and control group (n = 172). Randomization and allocation to the trial group were computer assisted. The trial was conducted remotely, without any personal contact. A drop out of 276 participants led to a primary analysis of 71 (IG n = 41; CG n = 31) participants. Sedentary behavior was assessed online using the Heidelberg Questionnaire for the Assessment of Sitting Behavior, at 5 time points: baseline (T0), 2 weeks (Z1), 4 weeks (Z2) 6 weeks (end of the intervention, T1), and follow-up 4 weeks after intervention (T2).

Results

Mixed ANOVA was carried out for T0 and T1 to reveal interaction effects between time and group. Mean differences show a highly practically and statistically relevant reduction in sitting time in the intervention group of 60 min between baseline and T1. No sustained effect of the intervention could be detected by analyzing sitting times at follow-up, 4 weeks after the end of the intervention.

Conclusions

Reduction in sedentary behavior in the intervention group after 6 weeks shows that the intervention is practically and statistically relevant. Limitations concerning the assessment method (questionnaire) as well as the sample size should be considered. The trial serves as a pilot study. However, the positive outcome of sitting time reduction paves the way for further research in this field.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-022-01747-7.

Influence of grit and healthy lifestyle behaviors on anxiety and depression in US adults at the beginning of the COVID-19 pandemic: Cross-sectional study

Background: The coronavirus disease 2019 (COVID-19) pandemic altered lifestyles and impacted mental health of many adults. Engaging in physical activity, avoiding prolonged sitting, and consuming a healthy diet improve mental health. The current study investigated the association between health-related lifestyle behaviors on feelings of anxiety and depression in adults during the early stages of the COVID-19 pandemic. Methods: Adults (n=796) living in the United States completed an internet-based survey in Spring 2020 that included validated survey instruments for moods, physical activity, sitting and dietary behaviors. Multivariate multiple regression models were used to assess the association between health-related lifestyle behaviors and feelings of anxiety and depression. Results: A majority (70.7%; 95% CI: [0.607, 0.807]) of participants met physical activity (PA) guidelines, 43.7% (95% CI: [0.287, 0.587]) sat for ≥ 8 hours per day, and 87.7% (95% CI [0.807, 0.947]) ate a healthy diet. Our final models explained 6.2% and 9.8% of the variance in anxiety and depression, respectively. Vigorous PA (anxiety: B=-0.111, 95% CI: [-0.171,0.000]; depression: B=-0.111, 95% CI: [-0.186,-0.037]) and dietary behaviors (anxiety: B=-0.112, 95% CI: [-0.180,-0.444]; depression: B=-0.112, 95% CI: [-0.213,-0.076]) were associated with reduced feelings of anxiety and depression while sitting time (anxiety: B=0.119, 95% CI: [0.000,0.199]; depression: B=0.119, 95% CI: [0.199,0.199]) were associated with greater feelings of anxiety and depression. Conclusion: Engaging in vigorous physically activity, reducing sitting time, and consuming a healthy diet was associated with reduced feelings of anxiety and depression during the early part of the pandemic. The aforementioned modifiable lifestyle behaviors are independent of each other suggesting improvements in one behavior may improve feelings of anxiety and depression.

Planning for a Healthy Aging Program to Reduce Sedentary Behavior: Perceptions among Diverse Older Adults

Reducing prolonged engagement in sedentary behavior is increasingly considered a viable pathway to older-adult health and continued functional ability. Community-based programs that aim to increase physical activity can improve programs' acceptability by integrating older adults' perspectives on sedentary behavior and healthy aging into their design. The purpose of this study was to better understand the perceptions of a diverse group of community-dwelling older adults regarding sedentary behavior and its influence on healthy aging. Six focus group discussions with forty-six participants took place across two senior centers in New York City. Self-report questionnaires about daily activity patterns, general health status, and typical sedentary behaviors were also completed by the participants and analyzed using descriptive statistics. The focus group discussions were audio-recorded, transcribed, and analyzed using inductive and deductive approaches and an ecological framework to identify salient themes. A qualitative analysis revealed that the participants were aware of the physical costs of engaging in prolonged sedentary behavior. However, many routine sedentary activities were perceived to be health-promoting and of psychological, cognitive, or social value. The insights gained can inform the development of senior-center programs and health-promotion messaging strategies that aim to reduce older adults' sedentary behavior.

Physical activity and sedentary behavior trajectories and their associations with quality of life, disability, and all-cause mortality

BACKGROUND

Physical activity (PA) and sedentary behavior (SB) are not stable conditions but change over time and among individuals, and both could have deleterious effects on health-related outcomes among older adults. This study aimed to identify the longitudinal trajectories of PA and SB and estimate their association with quality of life, disability, and all-cause mortality in a national sample of older Mexican adults.

METHODS

Data comes from three waves of the WHO Study on global AGEing and adult health (SAGE) in Mexico (2009, 2014, 2017). In total, 3209 older adults ages 50 and above were included. PA and SB were determined by using the Global Physical Activity Questionnaire (GPAQ). Disability was measured using the WHO Disability Assessment Schedule (WHODAS 2.0), quality of life using the WHOQOL (WHO Quality of Life) instrument, and all-cause mortality using a verbal autopsy. We used growth mixture modeling (GMM) to investigate the longitudinal trajectories of PA and SB. Three-level linear mixed effect models were used to estimate the associations of PA and SB with quality of life and disability and the Cox model for the association with all-cause mortality.

RESULTS

Three longitudinal trajectories of PA and SB were found: low-PA-decreasers, moderate-PA-decreasers, and high-PA-decreasers for PA; and low-maintainers, steep-decreasers, and steep-increasers for SB. Decreased quality of life, increased disability, and all-cause mortality were all consistently associated with worse PA and SB trajectories.

CONCLUSIONS

Our results highlight the need for health policies and prevention strategies that promote PA and limit SB in middle-aged adults. Further studies should consider these activities/behaviors as exposures that vary throughout life and work to identify vulnerable groups of older adults for whom physical activation interventions and programs would be most impactful.

Association of Membership at a Medical Fitness Facility With Adverse Health Outcomes

INTRODUCTION

Interventions that increase physical activity behavior can reduce morbidity and prolong life, but long-term effects in large populations are unproven. This study investigates the association of medical fitness facility membership and frequency of attendance with all-cause mortality and rate of hospitalization.

METHODS

A propensity weighted retrospective cohort study was conducted by linking individuals who attended medical fitness facilities in Winnipeg, Canada to provincial health administrative databases. Members aged ≥18 years who had ≥1 year of provincial health coverage from their index date between January 1, 2005 and December 31, 2015 were included. Controls were assigned a pseudo-index date at random on the basis of the frequency distribution of index dates in the intervention group. Members were stratified into low-frequency attenders (<1 weekly visit), moderate-frequency attenders (1-3 weekly visits), and high-frequency attenders (>3 weekly visits). The primary outcomes were time to all-cause mortality and rate of hospitalizations. Statistical analyses were performed between 2018 and 2020.

RESULTS

Among 19,300 adult members and 515,810 controls, members had a 60% lower risk of all-cause mortality during the first 651 days and 48% after 651 days. Membership was associated with a 13% lower risk of hospitalizations. A dose-response effect was apparent because higher weekly attendance was associated with a lower risk of hospitalizations (low frequency: 9%, moderate frequency: 20%, high frequency: 39%).

CONCLUSIONS

Membership at a medical fitness facility was associated with a reduced risk of all-cause mortality and hospitalizations. Healthcare systems should consider the medical fitness model as a preventative public health strategy to encourage physical activity participation.

Impact of the COVID-19 Pandemic on Sedentary Time and Behaviour in Children and Adults: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to quantify the change in sedentary time during the COVID-19 pandemic and its effect on health outcomes in the general population. One thousand six hundred and one articles published after 2019 were retrieved from five databases, of which 64 and 40 were included in the systematic review and meta-analysis, respectively. Studies were grouped according to population: children (<18 years), adults (18–64 years) and older adults (>65 years). Average sedentary time was calculated, with sub-analyses performed by country, behaviour type and health outcomes. Children were most affected, increasing their sedentary time by 159.5 ± 142.6 min day⁻¹, followed by adults (+126.9 ± 42.2 min day⁻¹) and older adults (+46.9 ± 22.0 min day⁻¹). There were no sex differences in any age group. Screen time was the only consistently measured behaviour and accounted for 46.8% and 57.2% of total sedentary time in children and adults, respectively. Increases in sedentary time were negatively correlated with global mental health, depression, anxiety and quality of life, irrespective of age. Whilst lockdown negatively affected all age groups, children were more negatively affected than adults or older adults, highlighting this population as a key intervention target. As lockdowns ease worldwide, strategies should be employed to reduce time spent sedentary. Trial registration: PROSPERO (CRD42020208909).

Physical activity combined with sedentary behaviour in the risk of mortality in older adults

OBJECTIVE

To examine the effects of physical activity (PA) and sedentary behaviour (SB), in isolation and combination, on all-cause mortality in older adults.

METHODS

Prospective, population-based cohort study. The data were collected from first wave in 2015 and the follow-up continued until 2020. The sample consisted of 332 older adult people aged ≥ 60 years-old, out of which 59 died. The level of PA and SB was assessed by the International Physical Activity Questionnaire (IPAQ). The older adults were divided into PA categorized as sufficiently active and insufficiently active and into high and low SB. We built four combinations of PA and SB. Also, we used the Cox proportional hazards regression with a 95% confidence interval with hazard ratio estimate so as to verify the mortality risks between PA, SB, and the combinations of PA and SB.

RESULTS

Insufficiently active individuals had higher risks of mortality compared to sufficiently active people. We observed no associations between SB and mortality separately; however, when evaluated in a combined way, insufficiently active individuals and with a high SB time had a higher chance of mortality compared to active individuals with a low SB time.

CONCLUSION

Our isolated analyses demonstrate that complying with PA recommendations reduces the risk of mortality; however, no association was found between the time of PA exposure with the time of SB. When analysing the combination, being physically inactive and with a long time of SB showed higher mortality rates, with SB being an enhancer of this risk. The results of this study show the interdependence of SB for PA performed at moderate to vigorous intensity. The understanding of this interrelation must be considered in the formulation of public health guidelines.

Culture and Health: Recent Developments and Future Directions 1

Evidence of cultural differences in relationships and emotions has accumulated over the past few decades. As findings on cultural differences in psychological processes have accumulated, there has been growing interest in investigating whether they have implications for other phenomena such as health. Using scientific advances from the MIDUS and MIDJA studies, both publicly available, we examine links between culture and health. We first briefly review the accumulated evidence on cultural influences on health correlates of psychosocial factors. We then feature two recent developments - a more micro-level perspective on biological factors that may be involved in the culture and health linkage, and a more macro-level view of socioeconomic inequality, which also matters for health. Both perspectives inform the pathways through which health effects occur. Finally, we conclude our review by highlighting the changing historical contexts surrounding these cross-cultural investigations. Specifically, we draw attention to widening of economic inequality across cultures and the world-wide COVID-19 pandemic. These happenings bring notable implications for future research on health across cultural contexts.

Physical Activity, Dietary Patterns, and Glycemic Management in Active Individuals with Type 1 Diabetes: An Online Survey

Individuals with type 1 diabetes (T1D) are able to balance their blood glucose levels while engaging in a wide variety of physical activities and sports. However, insulin use forces them to contend with many daily training and performance challenges involved with fine-tuning medication dosing, physical activity levels, and dietary patterns to optimize their participation and performance. The aim of this study was to ascertain which variables related to the diabetes management of physically active individuals with T1D have the greatest impact on overall blood glucose levels (reported as A1C) in a real-world setting. A total of 220 individuals with T1D completed an online survey to self-report information about their glycemic management, physical activity patterns, carbohydrate and dietary intake, use of diabetes technologies, and other variables that impact diabetes management and health. In analyzing many variables affecting glycemic management, the primary significant finding was that A1C values in lower, recommended ranges (<7%) were significantly predicted by a very-low carbohydrate intake dietary pattern, whereas the use of continuous glucose monitoring (CGM) devices had the greatest predictive ability when A1C was above recommended (≥7%). Various aspects of physical activity participation (including type, weekly time, frequency, and intensity) were not significantly associated with A1C for participants in this survey. In conclusion, when individuals with T1D are already physically active, dietary changes and more frequent monitoring of glucose may be most capable of further enhancing glycemic management.

Identifying individuals with multiple non-communicable disease risk factors in Kenya: a latent class analysis

OBJECTIVES

Non-communicable diseases (NCDs) are the leading causes of death globally. In Kenya, the number of deaths resulting from NCDs is projected to surpass malaria and tuberculosis by 2030. Studies in Kenya show increasing NCDs; the aim of the present study is to examine the clustering of NCDs and risk factors in Kenya.

STUDY DESIGN

This is a cross-sectional study using data from the 2015 Kenya STEPwise Survey.

METHODS

This study examined relationships between NCDs (e.g. obesity, hypertension and diabetes) and health behaviours (e.g. sedentary activity, and fruit and vegetable consumption). Survey probability weights, which estimated the sampling design effect, were applied to consider the sampling units, and stratifications were used during sampling so that the results could be generalisable to the national adult Kenyan population. In total, 4350 adults were included in the study sample.

RESULTS

Overall, 24.43% of participants were classified as having hypertension, 1.88% as having type 2 diabetes, and 27.94% were classified as being overweight or obese. The best-fit model was a four-class solution. Class 1 is best described as 'young with high NCD risk' and had the highest sedentary activity. Class 2 is best described as 'poor rural with lower NCD risk' with a high chance of smoking and alcohol consumption. Class 3 is best described as 'rural with high NCD risk' and had the highest fruit and vegetable consumption. Class 4 is best described as 'wealthy young urban dwellers with high NCD risk' with a high chance of alcohol consumption and smoking. Individuals in Class 4 had the highest chance (40%) of being overweight/obese, a 2% chance of type 2 diabetes and a 23% chance of having hypertension.

CONCLUSIONS

NCDs are clustered in groups with high-risk behaviours. The group with the highest chance of having NCDs also had the highest chance of engaging in high-risk behaviours. The findings of this study suggest that smoking and alcohol consumption increase NCD risk in rural areas. Tailored and targeted interventions are needed to curb the increasing NCD prevalence in Kenya.

Urban greenery cushions the decrease in leisure-time physical activity during the COVID-19 pandemic: A natural experimental study

The coronavirus disease 2019 (COVID-19) pandemic and related social distancing measures have altered the daily lifestyles of people worldwide. Although studies on this disease are emerging rapidly, less is known about the impacts of COVID-19 and urban greenery on leisure-time physical activity, which is critical to maintain health for urban residents during the pandemic. In this study, we used a natural experimental research design to identify whether urban greenery cushions the decrease in leisure-time physical activity caused by the pandemic and related social distancing measures in a high-density city. The two-wave physical activity data (before and during the pandemic) were collected for urban residents in neighborhoods with high or low levels of greenery. The results of difference-in-differences model suggest that urban greenery mitigated the decrease in physical activity during the pandemic. People who lived in greener neighborhoods experienced a lesser decrease in the leisure-time physical activity level than those who lived in less green neighborhoods. Additionally, people who lived in greener neighborhoods experienced increased levels of physical activity related to visits to country parks during the pandemic. These findings suggest that urban green spaces play a significant role in shaping physical activity and providing a refuge for the public during crises. Our study is among the first to investigate the impact of urban greenery on pandemic-induced changes in leisure-time physical activity in densely populated Asian cities, and our findings shed light on the potential protective role of urban greenery on public health during the COVID-19 pandemic and beyond.

Striking the Right Balance: Evidence to Inform Combined Physical Activity and Sedentary Behavior Recommendations

BACKGROUND

Crucial evidence gaps regarding: (1) the joint association of physical activity and sedentary time with health outcomes and (2) the benefits of light-intensity physical activity were identified during the development of recommendations for the World Health Organization Guidelines on physical activity and sedentary behavior (SB). The authors present alternative ways to evidence the relationship between health outcomes and time spent in physical activity and SB and examine how this could be translated into a combined recommendation in future guidelines.

METHODS

We used compositional data analysis to quantify the dose-response associations between the balance of time spent in physical activity and SB with all-cause mortality. The authors applied this approach using 2005-2006 National Health and Nutrition Examination Survey accelerometer data.

RESULTS

Different combinations of time spent in moderate- to vigorous-intensity physical activity, light-intensity physical activity, and SB are associated with similar all-cause mortality risk level. A balance of more than 2.5 minutes of moderate- to vigorous-intensity physical activity per hour of daily sedentary time is associated with the same magnitude of risk reduction for all-cause mortality as obtained by being physically active according to the current recommendations.

CONCLUSION

This method could be applied to provide evidence for more flexible recommendations in the future with options to act on different behaviors depending on individuals' circumstances and capacity.

Fast, Optimal, and Targeted Predictions using Parametrized Decision Analysis

Prediction is critical for decision-making under uncertainty and lends validity to statistical inference. With targeted prediction, the goal is to optimize predictions for specific decision tasks of interest, which we represent via functionals. Although classical decision analysis extracts predictions from a Bayesian model, these predictions are often difficult to interpret and slow to compute. Instead, we design a class of parametrized actions for Bayesian decision analysis that produce optimal, scalable, and simple targeted predictions. For a wide variety of action parametrizations and loss functions-including linear actions with sparsity constraints for targeted variable selection-we derive a convenient representation of the optimal targeted prediction that yields efficient and interpretable solutions. Customized out-of-sample predictive metrics are developed to evaluate and compare among targeted predictors. Through careful use of the posterior predictive distribution, we introduce a procedure that identifies a set of near-optimal, or acceptable targeted predictors, which provide unique insights into the features and level of complexity needed for accurate targeted prediction. Simulations demonstrate excellent prediction, estimation, and variable selection capabilities. Targeted predictions are constructed for physical activity data from the National Health and Nutrition Examination Survey (NHANES) to better predict and understand the characteristics of intraday physical activity.

Effects of Classroom Active Desks on Children and Adolescents' Physical Activity, Sedentary Behavior, Academic Achievements and Overall Health: A Systematic Review

The purpose of this systematic review was to examine the effects of active desks in the school setting on sedentary behavior, physical activity, academic achievements and overall health among children and adolescents aged 5-17 years. A systematic literature search was conducted using five databases until October 2020. Twenty-three studies were included. Studies reported an increase of around 36% in energy expenditure for cycling desks and between 15% and 27.7% for upright active desks. Children increased inhibitory control and selective attention capacity while using cycling desks. A heterogeneous quality of design and of results were observed limiting comparisons and conclusions for each active desk. Despite the lack of strong methodology for the included studies, active desks appear to be a promising intervention in classrooms to improve health-related outcomes in children aged 5-17 years. Due to weak methodology, future studies with stronger study designs and methodology are needed to better inform policy and practice about the role of classroom active desks on health-related outcomes in children and adolescents.

Association of Physical Activity and Poor Health Outcomes in Patients With Advanced CKD

RATIONALE & OBJECTIVE

Chronic kidney disease (CKD) is associated with declining physical function and activity. In the general population, lower physical activity is associated with poorer quality of life and greater all-cause mortality. The aim of this study was to assess if lower physical activity levels are associated with adverse health outcomes in patients with advanced CKD.

STUDY DESIGN

A multicenter prospective cohort study.

SETTING & PARTICIPANTS

579 adult patients with CKD glomerular filtration rate categories 4 and 5 (G4-G5) treated at 4 Canadian multidisciplinary kidney health clinics between 2012 and 2018.

EXPOSURE

Patient-reported measures of physical activity using the Physical Activity Scale for the Elderly (PASE) questionnaire and subsequently stratified PASE scores into tertiles.

OUTCOME

All-cause mortality, progression to kidney failure, and future falls.

ANALYTICAL APPROACH

Outcomes were analyzed using time-dependent proportional hazards models and logistic regression models.

RESULTS

In 1,193 days of follow-up observation, 118 patients died, 204 progressed to dialysis, and 129 reported a fall. When compared with low physical activity, higher levels of physical activity were associated with a 52% lower all-cause mortality (adjusted HR, 0.48; 95% CI, 0.27-0.85) in models adjusted for age, sex, and comorbidity. No associations were detected between higher levels of physical activity and either slower progression to kidney failure or a lower rate of future falls.

LIMITATIONS

Physical activity and falls were self-reported. Our population was of limited racial/ethnic diversity, which may affect generalizability. Findings were observational and do not indicate whether interventions targeting physical activity may affect adverse health outcomes.

CONCLUSIONS

Higher levels of physical activity were associated with about 50% lower all-cause mortality in the advanced CKD population. These findings are consistent with a potential benefit from maintained physical activity as patients approach kidney failure.

Objectively measured physical activity and all cause mortality: A systematic review and meta-analysis

Current physical activity recommendations have been based on evidence from systematic reviews of questionnaire-based data. Questionnaire-based physical activity data are subject to both random and non-random error. If the estimated association between physical activity and health outcomes was different when a more accurate, objective measure was used, this would have important health policy implications for physical activity. We conducted a systematic review and meta-analysis of published cohort studies that investigated the association between an objective measure of physical activity and all cause mortality. We searched PubMed, Scopus, Embase, Cochrane library, and SPORTDiscus for prospective cohort studies that examined the association between objectively measured (accelerometer, pedometer, or doubly labeled water method) physical activity and mortality in adults aged≥18 years, of either sex. Summary hazard ratios and 95% confidence interval [CI]s were computed using random-effects models. Thirty-three articles from 15 cohort studies were identified that together ascertained 3903 deaths. The mean years of follow-up ranged from 2.3-14.2 years. Individuals in the highest category of light, moderate-to-vigorous, and total physical activity had 40% (95%CI 20% to 55%), 56% (95%CI 41% to 67%), and 67% (95%CI 57% to 75%), respectively, lower risk for mortality compared to individuals in the lowest category of light, moderate-to-vigorous, and total physical activity. The summary hazard ratio for objectively measured physical activity and all cause mortality is lower than previously estimated from questionnaire based studies. Current recommendations for physical activity that are based on subjective measurement may underestimate the true reduction in mortality risk associated with physical activity.

Additive Functional Cox Model

We propose the Additive Functional Cox Model to flexibly quantify the association between functional covariates and time to event data. The model extends the linear functional proportional hazards model by allowing the association between the functional covariate and log hazard to vary non-linearly in both the functional domain and the value of the functional covariate. Additionally, we introduce critical transformations of the functional covariate which address the weak model identifiability in areas of information sparsity and discuss their impact on interpretation and inference. We also introduce a novel estimation procedure that accounts for identifiability constraints directly during model fitting. Methods are applied to the National Health and Nutrition Examination Survey (NHANES) 2003-2006 accelerometry data and quantify new and interpretable circadian patterns of physical activity that are associated with all-cause mortality. We also introduce a simple and novel simulation framework for generating survival data with functional predictors which resemble the observed data. The accompanying inferential R software is fast, open source and publicly available. Our data application and simulations are fully reproducible through the accompanying vignette.

Association between obesity and sedentary behavior in adults

Abstract Although sedentary behavior (SB) is related to the development of metabolic diseases, there is still no consensus in literature about the association between accelerometer-based SB and obesity, especially adjusted for cardiovascular risk factors and level of daily physical activities. The aim was to evaluate the association between obesity and SB adjusted for potential confounders in adults. Data from 780 participants of the Epidemiology and Human Movement (EPIMOV) Study were analyzed. Body weight, body mass index (BMI), and fat body mass as percentage (%FBM) (bioelectrical impedance) were obtained and, then, used to stratify participants. SB was objectively measured using triaxial waist-worn accelerometers placed above the dominant hip during waking hours for at least four consecutive days (4-7 days). SB and its pattern were not significantly different between obesity groups. Although SB presented some significant correlations with obesity, the correlation and determination coefficient indicated weak association between SB and obesity (e.g., BMI and %FBM). Obesity presented little or no association with SB and its pattern after adjustment for potential confounders, especially when SB is measured through accelerometry.

Biomarker association with cardiovascular disease and mortality - The role of fibrinogen. A report from the NHANES study

BACKGROUND

While fibrinogen is a known cardiovascular disease (CVD) risk marker, its quantitative input to mortality risk is a topic of debate.

METHODS

We investigated the contribution of fibrinogen, among that of other biomarkers, to prevalent CVD and incident CVD mortality in 4487 participants of the US National Health and Nutrition Examination Survey (NHANES). Participants were observed for a median period of 14 years, resulting in more than 58,000 person-years.

RESULTS

At baseline 551 participants had CVD and during follow up, 1339 all-cause deaths occurred, 321 (24%) of which were due to CVD. Hierarchical cluster analysis and principal component analysis (PCA) were performed to derive clusters of association between biomarkers. Next, structural equation modelling was performed to investigate the association of these clusters with baseline CVD and all-cause and CVD mortality during follow-up. Mediation analysis was used to determine which biomarkers played a mediatory role between prevalent CVD and future mortality. Fibrinogen clustered with C-reactive protein only and was associated with CVD at baseline (p < 0.0001) and with all-cause (p < 0.001) and CVD (p < 0.001) mortality at follow-up. Only fibrinogen (4.7%), followed by gamma-glutamyl transferase (GGT) (3.5%) and uric acid (2.3%) were identified as possible mediators between CVD status and all-cause mortality, with fibrinogen (3.2%) and GGT (3.1%) the only mediators between CVD status and CVD mortality.

CONCLUSION

This data shows that fibrinogen is not only cross-sectionally associated with CVD, but also contributes to all-cause and CVD mortality at follow-up. It furthermore appears to mediate the association between prevalent CVD and both all-cause and CVD mortality.

Physical activity and risk of cardiovascular events and all-cause mortality among kidney transplant recipients

BACKGROUND

Insufficient physical activity (PA) may increase the risk of all-cause mortality and cardiovascular disease (CVD) morbidity and mortality among kidney transplant recipients (KTRs), but limited research is available. We examine the relationship between PA and the development of CVD events, CVD death and all-cause mortality among KTRs.

METHODS

A total of 3050 KTRs enrolled in an international homocysteine-lowering randomized controlled trial were examined (38% female; mean age 51.8 ± 9.4 years; 75% white; 20% with prevalent CVD). PA was measured at baseline using a modified Yale Physical Activity Survey, divided into tertiles (T1, T2 and T3) from lowest to highest PA. Kaplan-Meier survival curves were used to graph the risk of events; Cox proportional hazards regression models examined the association of baseline PA levels with CVD events (e.g. stroke, myocardial infarction), CVD mortality and all-cause mortality over time.

RESULTS

Participants were followed up to 2500 days (mean 3.7 ± 1.6 years). The cohort experienced 426 CVD events and 357 deaths. Fully adjusted models revealed that, compared to the lowest tertile of PA, the highest tertile experienced a significantly lower risk of CVD events {hazard ratio [HR] 0.76 [95% confidence interval (CI) 0.59-0.98]}, CVD mortality [HR 0.58 (95% CI 0.35-0.96)] and all-cause mortality [HR 0.76 (95% CI 0.59-0.98)]. Results were similar in unadjusted models.

CONCLUSIONS

PA was associated with a reduced risk of CVD events and all-cause mortality among KTRs. These observed associations in a large, international sample, even when controlling for traditional CVD risk factors, indicate the potential importance of PA in reducing CVD and death among KTRs.

The Predictive Performance of Objective Measures of Physical Activity Derived From Accelerometry Data for 5-Year All-Cause Mortality in Older Adults: National Health and Nutritional Examination Survey 2003-2006

BACKGROUND

Declining physical activity (PA) is a hallmark of aging. Wearable technology provides reliable measures of the frequency, duration, intensity, and timing of PA. Accelerometry-derived measures of PA are compared with established predictors of 5-year all-cause mortality in older adults in terms of individual, relative, and combined predictive performance.

METHODS

Participants aged between 50 and 85 years from the 2003-2006 National Health and Nutritional Examination Survey (NHANES, n = 2,978) wore a hip-worn accelerometer in the free-living environment for up to 7 days. A total of 33 predictors of 5-year all-cause mortality (number of events = 297), including 20 measures of objective PA, were compared using univariate and multivariate logistic regression.

RESULTS

In univariate logistic regression, the total activity count was the best predictor of 5-year mortality (Area under the Curve (AUC) = 0.771) followed by age (AUC = 0.758). Overall, 9 of the top 10 predictors were objective PA measures (AUC from 0.771 to 0.692). In multivariate regression, the 10-fold cross-validated AUC was 0.798 for the model without objective PA variables (9 predictors) and 0.838 for the forward selection model with objective PA variables (13 predictors). The Net Reclassification Index was substantially improved by adding objective PA variables (p < .001).

CONCLUSIONS

Objective accelerometry-derived PA measures outperform traditional predictors of 5-year mortality, including age. This highlights the importance of wearable technology for providing reproducible, unbiased, and prognostic biomarkers of health.

The long-term impact of restricting cycling and walking during high air pollution days on all-cause mortality: Health impact Assessment study

Regular active commuting, such as cycling and walking to and from the workplace, is associated with lower all-cause mortality through increased physical activity (PA). However, active commuting may increase intake of fine particles (PM_2.5), causing negative health effects. The purpose of this study is to estimate the combined risk of PA and air pollution for all-cause mortality among active commuters who, on days with high PM_2.5 levels, switch to commuting by public transportation or work from home. Towards this purpose, we developed a Health Impact Assessment model for six cities (Helsinki, London, Sao Paulo, Warsaw, Beijing, New Delhi) using daily, city-specific PM_2.5 concentrations. For each city we estimated combined Relative Risk (RR) due to all-cause mortality for the PA benefits and PM_2.5 risks with different thresholds concentrations. Everyday cycling to work resulted in annual all-cause mortality risk reductions ranging from 28 averted deaths per 1000 cyclists (95% confidence interval (CI): 20-38) in Sao Paolo to 12 averted deaths per 1000 cyclists (95% CI: 5-19) in Beijing. Similarly, for everyday walking, the reductions in annual all-cause mortality ranged from 23 averted deaths per 1000 pedestrians (95 CI: 16-31) in Sao Paolo to 10 averted deaths per 1000 pedestrians (95%CI: 5-16) in Beijing. Restricting active commuting during days with PM_2.5 levels above specific air quality thresholds would not decrease all-cause mortality risk in any examined city. On the contrary, all-cause mortality risk would increase if walking and cycling are restricted in days with PM_2.5 concentrations below 150 μg/m³ in highly polluted cities (Beijing, New Delhi). In all six cities, everyday active commuting reduced all-cause mortality when benefits of PA and risk or air pollution were combined. Switching to working from home or using public transport on days with high air pollution is not expected to lead to improved all-cause mortality risks.

Fractal Complexity of Daily Physical Activity Patterns Differs With Age Over the Life Span and Is Associated With Mortality in Older Adults

BACKGROUND

Accelerometers are included in a wide range of devices that monitor and track physical activity for health-related applications. However, the clinical utility of the information embedded in their rich time-series data has been greatly understudied and has yet to be fully realized. Here, we examine the potential for fractal complexity of actigraphy data to serve as a clinical biomarker for mortality risk.

METHODS

We use detrended fluctuation analysis (DFA) to analyze actigraphy data from the National Health and Nutrition Examination Survey (NHANES; n = 11,694). The DFA method measures fractal complexity (signal self-affinity across time-scales) as correlations between the amplitude of signal fluctuations in time-series data across a range of time-scales. The slope, α, relating the fluctuation amplitudes to the time-scales over which they were measured describes the complexity of the signal.

RESULTS

Fractal complexity of physical activity (α) decreased significantly with age (p = 1.29E-6) and was lower in women compared with men (p = 1.79E-4). Higher levels of moderate-to-vigorous physical activity in older adults and in women were associated with greater fractal complexity. In adults aged 50-79 years, lower fractal complexity of activity (α) was associated with greater mortality (hazard ratio = 0.64; 95% confidence interval = 0.49-0.82) after adjusting for age, exercise engagement, chronic diseases, and other covariates associated with mortality.

CONCLUSIONS

Wearable accelerometers can provide a noninvasive biomarker of physiological aging and mortality risk after adjusting for other factors strongly associated with mortality. Thus, this fractal analysis of accelerometer signals provides a novel clinical application for wearable accelerometers, advancing efforts for remote monitoring of physiological health by clinicians.

Does meeting physical activity recommendations ameliorate association between television viewing with cardiovascular disease risk? A cross-sectional, population-based analysis

OBJECTIVES

As a common form of sedentary behaviour, television viewing is associated with an increase in body mass index (BMI) as well as overall cardiovascular disease (CVD) risk. This study examined the extent to which meeting the recommended volume of weekly physical activity (PA) reduced the association between television viewing with the outcomes of BMI and CVD risk. A second aim was to determine the number of hours (ie, cut-point) of daily television viewing that conferred a higher BMI and CVD risk for a large population-based sample of adults.

DESIGN

Population-based, cross-sectional study.

SETTING

UK Biobank recruited across 35 centres in the UK between 2006 and 2010.

PRIMARY OUTCOME

CVD risk, as measured by the 30-year Framingham risk score.

RESULTS

Linear regression models indicated that every additional hour of television viewing per day was associated with a 3% increase in CVD risk (aCoeff=0.03, d=0.16, p<0.0001); the interaction between television viewing with meeting PA guidelines was marginally associated with CVD risk (aCoeff=0.0010, d=0.01, p=0.014). Each additional hour of television viewing per day was associated with a 0.54 increase in BMI (aCoeff=0.54, d=0.13, p<0.0001); the interaction between television viewing with meeting PA guidelines was not significantly associated with BMI. Regression tree models of the study outcomes revealed that 2.5 hours of television viewing was associated with pronounced increases in BMI and CVD risk.

CONCLUSIONS

These data underscore the independent association between television viewing with cardiovascular risk and suggest that reducing television viewing to less than 2.5 hours per day, even in physically active adults, is a clinical and public health priority.

Activity Level as a Mortality Predictor in a Population Sample after Typical Underwriting Exclusions and Laboratory Scoring

  Objectives.- To quantify the effect of physical activity on the mortality rates of healthy individuals in a population sample, after controlling for other sources of mortality risk. Background.- The widespread availability of activity monitors has spurred life insurance companies to consider incorporating such data into their underwriting practices. Studies have shown that sedentary lifestyles are associated with poor health outcomes and higher risks of death. The aim of this paper is to investigate how well certain measures of activity predict mortality when controlled for other known predictors of mortality including a multivariate laboratory based risk score. Methods.- Data were obtained from the National Health and Nutrition Examination Survey (NHANES) for the years 1999 through 2014. Laboratory and biometric data were scored for mortality risk using a previously developed proprietary algorithm (CRL SmartScore). Data on activity were obtained from the NHANES questionnaires pertaining to activity. In a second analysis, data were obtained from pedometers worn for 1 week by NHANES participants (years 2003-2004, and 2005-2006 only). Before analysis, cases were selected based on commonly used life insurance underwriting criteria to remove from consideration those who have major health issues, which would ordinarily preclude an offer of life insurance. Results.-In fully-adjusted Cox model which included survey-based MET*hours per day as a 3-level categorical variable, the moderate and minimal levels of activity were associated with hazard ratios of 1.15 (95% CI: 1.04-1.28) and 1.38 (95% CI: 1.23-1.56), respectively, when compared to the highest level of activity. When treated as a continuous variable, the fully adjusted model the HR for MET*hours per day was 0.91 (95% CI: 0.87-0.95). In fully adjusted models using pedometer data, the percentage of wear time spent sedentary was associated with mortality (HR: 1.19, 95% CI: 1.09-1.31), while average counts per minute were negatively associated with mortality (HR: 0.82, CI: 0.75-0.90). Conclusions.-It is clear from these results that high proportions of sedentary time are associated with increased mortality, whether the sedentary time is quantified via questionnaire or pedometer. Because both laboratory scores and activity levels remain significant in Cox models where both are included, these factors are largely independent, indicating that they are measuring distinct influences on the risk of mortality.

Trends in alcohol consumption in relation to cause-specific and all-cause mortality in the United States: a report from the NHANES linked to the US mortality registry

BACKGROUND

Excessive alcohol use is the third leading cause of mortality in the United States, where alcohol use consistently increased over the last decades. This trend is currently maintained, despite regulatory policies aimed to counteract it. While the increased health risks resulting from alcohol use are evident, some open questions regarding alcohol use and its consequences in the US population remain.

OBJECTIVES

The current work aims to evaluate the relation between alcohol consumption trends over a period of 15 y with all-cause and cause-specific mortality. In addition, we evaluate the adequacy of the current alcohol recommended limits according to the 2015-2020 US Dietary Guidelines for Americans (USDGA).

METHODS

This was a prospective population-based study defined by the NHANES conducted over the period 1999-2014 linked to US mortality registry in 2015.

RESULTS

The sample, composed of 34,672 participants, was observed for a median period of 7.8 y, totaling 282,855 person-years. In the present sample, 4,303 deaths were observed. Alcohol use increased during the period 1999-2014. Alcohol use above the current US recommendations was associated with increased all-cause and cause-specific mortality risk, ranging from 39% to 126%. A proportion of these deaths, ranging from 19% to 26%, could be theoretically prevented if US citizens followed current guidelines, and 13% of all-cause deaths in men could be avoided if the current US guidelines for women (1 standard drink/d) were applied to them.

CONCLUSIONS

The present study provides evidence in support of limiting alcohol intake in adherence to the USDGA recommendations.

A Scoping Review of Digital Tools to Reduce Sedentary Behavior or Increase Physical Activity in Knowledge Workers

Background: There is increasing interest in the role that technology can play in improving the vitality of knowledge workers. A promising and widely adopted strategy to attain this goal is to reduce sedentary behavior (SB) and increase physical activity (PA). In this paper, we review the state-of-the-art SB and PA interventions using technology in the office environment. By scoping the existing landscape, we identified current gaps and underexplored possibilities. We discuss opportunities for future development and research on SB and PA interventions using technology. Methods: A systematic search was conducted in the Association for Computing Machinery digital library, the interdisciplinary library Scopus, and the Institute of Electrical and Electronics Engineers Xplore Digital Library to locate peer-reviewed scientific articles detailing SB and PA technology interventions in office environments between 2009 and 2019. Results: The initial search identified 1130 articles, of which 45 studies were included in the analysis. Our scoping review focused on the technologies supporting the interventions, which were coded using a grounded approach. Conclusion: Our findings showed that current SB and PA interventions using technology provide limited possibilities for physically active ways of working as opposed to the common strategy of prompting breaks. Interventions are also often offered as additional systems or services, rather than integrated into existing office infrastructures. With this work, we have mapped different types of interventions and provide an increased understanding of the opportunities for future multidisciplinary development and research of technologies to address sedentary behavior and physical activity in the office context.

Original research Socio-demographic patterning of self-reported physical activity and sitting time in Latin American countries: findings from ELANS

Background

Low levels of physical activity (PA) and prolonged sitting time (ST) increase the risk of non-communicable diseases and mortality, and can be influenced by socio-demographic characteristics. The aim of this study was to use self-report data to characterise socio-demographic patterns of PA and ST in eight Latin American countries.

Methods

Data were obtained from the Latin American Study of Nutrition and Health (ELANS), a household population-based, multi-national, cross-sectional survey (n = 9218, aged 15–65 years), collected from September 2014 to February 2015. Transport and leisure PA and ST were assessed using the International Physical Activity Questionnaire–long version. Overall and country-specific mean and median levels of time spent in transport and leisure PA and ST were compared by sex, age, socioeconomic and education level.

Results

Mean levels of transport and leisure PA were 220.3 min/week (ranging from 177.6 min/week in Venezuela to 275.3 min/week in Costa Rica) and 316.4 min/week (ranging from 272.1 min/week in Peru to 401.4 min/week in Ecuador). Transport and leisure PA were higher (p < 0.005) in men than women with mean differences of 58.0 and 34.0 min/week. The mean and median for transport PA were similar across age groups (15–29 years: mean 215.5 and median 120 min/week; 30–59 years: mean 225.0 and median 120 min/week; ≥60 years: mean 212.0 and median 120 min/week). The median time spent in transport and leisure PA between three strata of socioeconomic and education levels were similar. The prevalence of not meeting PA recommendations were 69.9% (95% CI: 68.9–70.8) for transport and 72.8% (95% CI: 72.0–73.7) for leisure. Men, younger people (15–29 years), individuals with higher socioeconomic and education levels spent significantly (p < 0.001) more time sitting than women, older people (30–59 years and ≥ 60 years) and those in the middle and low socioeconomic and education groups, respectively.

Conclusions

Transport and leisure PA and ST range widely by country, sex, and age group in Latin America. Programs for promoting leisure and transport PA and reducing ST in Latin America should consider these differences by age and gender and between countries.

Trial registration

ClinicalTrials.Gov NCT02226627. Retrospectively registered on August 27, 2014.

Predictors of real-life mobility in community-dwelling older adults: an exploration based on a comprehensive framework for analyzing mobility

BACKGROUND

Reduced mobility is associated with a plethora of adverse outcomes. To support older adults in maintaining their independence, it first is important to have deeper knowledge of factors that impact on their mobility. Based on a framework that encompasses demographical, environmental, physical, cognitive, psychological and social domains, this study explores predictors of different aspects of real-life mobility in community-dwelling older adults.

METHODS

Data were obtained in two study waves with a total sample of n = 154. Real-life mobility (physical activity-based mobility and life-space mobility) was assessed over one week using smartphones. Active and gait time and number of steps were calculated from inertial sensor data, and life-space area, total distance, and action range were calculated from GPS data. Demographic measures included age, gender and education. Physical functioning was assessed based on measures of cardiovascular fitness, leg and handgrip strength, balance and gait function; cognitive functioning was assessed based on measures of attention and executive function. Psychological and social assessments included measures of self-efficacy, depression, rigidity, arousal, and loneliness, sociableness, perceived help availability, perceived ageism and social networks. Maximum temperature was used to assess weather conditions on monitoring days.

RESULTS

Multiple regression analyses indicated just physical and psychological measures accounted for significant but rather low proportions of variance (5-30%) in real-life mobility. Strength measures were retained in most of the regression models. Cognitive and social measures did not remain as significant predictors in any of the models.

CONCLUSIONS

In older adults without mobility limitations, real-life mobility was associated primarily with measures of physical functioning. Psychological functioning also seemed to play a role for real-life mobility, though the associations were more pronounced for physical activity-based mobility than life-space mobility. Further factors should be assessed in order to achieve more conclusive results about predictors of real-life mobility in community-dwelling older adults.

The Relationship of Physical Activity and Obesity with the Incidence of Hypertension in Adults Aged 26-45 Years in Medan

BACKGROUND:

The incidence rate of hypertension is increasing in Indonesia concerning unhealthy behaviours such as unhealthy physical activity and eating pattern which trigger obesity. In Indonesia, the prevalence of hypertension in > 18-year-old people was 34.1% in 2018.

AIM:

The objective of the research was to find out the relationship between physical activity and obesity with the incidence of hypertension in adults (26-45 years old) in Medan.

METHODS:

The research was done in Medan, using a case-control study design. The samples were 150 hypertension patients, taken by using proportional allocation: 75 of them were in the case group and the other 75 of them were in the control group. The data were gathered by conducting interviews, measurement, and questionnaires and analysed by using simple logistic regression test.

RESULTS:

The result of the research showed that there was significant relationship of physical activity (p = 0.000; OR = 3.6; 95% CI, 1.802-7.270) and obesity (p = 0.000; OR = 4; 95% CI, 2.030-7.900) with the incidence of hypertension in 26-45-year-old respondents.

CONCLUSION:

Make a habit of a healthy lifestyle in their daily life by doing physical activity regularly and good eating pattern to forestall hypertension.

Do older English adults exhibit day-to-day compensation in sedentary time and in prolonged sedentary bouts? An EPIC-Norfolk cohort analysis

INTRODUCTION

Compensatory behaviours may be one of the reasons for the limited success of sedentary time interventions in older adults, but this possibility remains unexplored. Activity compensation is the idea that if we change activity levels at one time we compensate for them at a later time to maintain a set point. We aimed to assess, among adults aged ≥60 years, whether sedentary time and time spent in prolonged sedentary bouts (≥30 mins) on one day were associated with sedentary time and time spent in prolonged sedentary bouts (≥30 mins) on the following day. We also sought to determine whether these associations varied by sociodemographic and comorbid factors.

METHODS

Sedentary time was assessed for seven days using hip-worn accelerometers (ActiGraph GT1M) for 3459 adults who participated in the EPIC-Norfolk Study between 2004 and 2011. We assessed day-to-day associations in total and prolonged bouts of sedentary time using multi-level regressions. We included interaction terms to determine whether associations varied by age, sex, smoking, body mass index, social class, retirement, education and comorbid factors (stroke, diabetes, myocardial infarction and cancer).

RESULTS

Participants (mean age = 70.3, SD = 6.8 years) accumulated 540 sedentary mins/day (SD = 80.1). On any given day, every 60 minutes spent in sedentary time was associated with 9.9 extra sedentary minutes on the following day (95% CI 9.0, 10.2). This association was greater in non-retired compared to retired participants (non-retired 2.57 extra minutes, p = 0.024) and in current compared to former and never-smokers (5.26 extra mins for current vs former; 5.52 extra mins for current vs never, p = 0.023 and 0.017, respectively). On any given day, every 60 minutes spent in prolonged bouts was associated with 7.8 extra minutes in these bouts the following day (95% CI 7.6, 8.4). This association was greater in older individuals (0.18 extra minutes/year of age, 95% CI 0.061, 0.29), and for retired versus non-retired (retired 2.74 extra minutes, 95% CI 0.21, 5.74).

CONCLUSION

Older adults did not display day-to-day compensation. Instead, individuals demonstrate a large stable component of day-to-day time spent sedentary and in prolonged bouts with a small but important capacity for positive variation. Therefore older adults appear to be largely habitual in their sedentary behaviour. Strategies to augment these patterns may be possible, given they may differ by age, smoking, and working status.