Relationship of television time with accelerometer-derived sedentary time: NHANES

Causal effects of sedentary behaviours on the risk of migraine: A univariable and multivariable Mendelian randomization study

BACKGROUND

Migraine is a common and burdensome neurological disorder. The causal relationship between sedentary behaviours (SBs) and migraine remains instinct. We aimed to evaluate the roles of SBs including watching TV, using computer and driving in the risk of migraine.

METHODS

We conducted a univariable and multivariable Mendelian randomization (MR) study based on summary datasets of large genome-wide association studies. The inverse variance weighted method was utilized as the primary analytical tool. Cochran's Q, MR-Egger intercept test, MR pleiotropy residual sum and outlier and leave-one-out were conducted as sensitivity analysis. Additionally, we performed a meta-analysis to combine the causal estimates.

RESULTS

In the discovery analysis, we identified causal associations between time spent watching TV and an increased risk of migraine (p = 0.015) and migraine without aura (MO) (p = 0.002). Such causalities with increasing risk of migraine (p = 0.005), and MO (p = 0.006) were further verified using summary datasets from another study in the replication analysis. There was no significant causal association found between time spent using computer, driving and migraine or its two subtypes. The meta-analysis and multivariable MR analysis also strongly supported the causal relationships between time spent watching TV and an increased risk of migraine (p = 0.0003 and p = 0.034), as well as MO (p < 0.0001 and p = 0.0004), respectively. These findings were robust under all sensitivity analysis.

CONCLUSIONS

Our study suggested that time spent watching TV may be causally associated with an increased risk of migraine, particularly MO. Large-scale and well-designed cohort studies may be warranted for further validation.

SIGNIFICANCE STATEMENT

This study represents the first attempt to investigate whether a causal relationship exists between SBs and migraine. Utilizing MR analysis helps mitigate reverse causation bias and confounding factors commonly encountered in observational cohorts, thereby enhancing the robustness of derived causal associations. Our MR analysis revealed that time spent watching TV may serve as a potential risk factor for migraine, particularly MO.

Modifiable Lifestyle, Sedentary Behaviors and the Risk of Frailty: A Univariate and Multivariate Mendelian Randomization Study

This research conducted a two-sample univariate and multivariate Mendelian Randomization (MR) analysis to explore the causal link between different types of leisure sedentary behavior (LSB) and frailty. Independent instrumental variables significantly associated with sedentary behaviors (p < 5 × 10-8) are obtained from a genome-wide association study (GWAS) of 422,218 individuals, and Frailty Index (FI) are derived from the latest GWAS dataset of 175,226 individuals. MR analysis is conducted using inverse variance weighting, MR-Egger, weighted median, simple mode, and weighted mode, supplemented by MRAPSS. Univariate MR revealed that sedentary behaviors such as watching television increased the risk of frailty (OR, 1.271; 95% CI: 1.202-1.345; p = 6.952 × 10-17), as sedentary driving behaviors are done (OR, 1.436; 95% CI: 1.026-2.011; p = 0.035). Further validation through APSS, taking into account cryptic relatedness, stratification, and sample overlap, maintained the association between television viewing and increased frailty risk (OR, 1.394; 95% CI: 1.266-1.534; p = 1.143 × 10-11), while the association with driving dissipated. In multivariate inverse variance weighted (IVW) analysis, after adjusting for C-reactive protein (CRP) levels, television Sedentary behavior (SB) inversely affected frailty (OR, 0.782; 95% CI: 0.724-0.845; p = 4.820 × 10-10). This study indicates that televisio SB significantly increases the risk of frailty, suggesting potential biological heterogeneity behind specific sedentary activities. This process may interact with inflammation, influencing the development of frailty.

StandUPTV: Preparation and optimization phases of a mHealth intervention to reduce sedentary screen time in adults

Recreational sedentary screen time (rSST) is the most prevalent sedentary behavior for adults outside of work, school, and sleep, and is strongly linked to poor health. StandUPTV is a mHealth trial that uses the Multiphase Optimization Strategy (MOST) framework to develop and evaluate the efficacy of three theory-based strategies for reducing rSST among adults. This paper describes the preparation and optimization phases of StandUPTV within the MOST framework. We identified three candidate components based on previous literature: (a) rSST electronic lockout (LOCKOUT), which restricts rSST through electronic means; (b) adaptive prompts (TEXT), which provides adaptive prompts based on rSST behaviors; and (c) earning rSST through increased moderate-vigorous physical activity (MVPA) participation (EARN). We also describe the mHealth iterative design process and the selection of an optimization objective. Finally, we describe the protocol of the optimization randomized controlled trial using a 23 factorial experimental design. We will enroll 240 individuals aged 23-64 y who engage in >3 h/day of rSST. All participants will receive a target to reduce rSST by 50% and be randomized to one of 8 combinations representing all components and component levels: LOCKOUT (yes vs. no), TEXT (yes vs. no), and EARN (yes vs. no). Results will support the selection of the components for the intervention package that meet the optimization objective and are acceptable to participants. The optimized intervention will be tested in a future evaluation randomized trial to examine reductions in rSST on health outcomes among adults.

Leisure time television watching, computer use and risks of breast, colorectal and prostate cancer: A Mendelian randomisation analysis

BACKGROUND

Sedentary behaviours have been associated with increased risks of some common cancers in epidemiological studies; however, it is unclear if these associations are causal.

METHODS

We used univariable and multivariable two-sample Mendelian randomisation (MR) to examine potential causal relationships between sedentary behaviours and risks of breast, colorectal and prostate cancer. Genetic variants associated with self-reported leisure television watching and computer use were identified from a recent genome-wide association study (GWAS). Data related to cancer risk were obtained from cancer GWAS consortia. A series of sensitivity analyses were applied to examine the robustness of the results to the presence of confounding.

RESULTS

A 1-standard deviation (SD: 1.5 h/day) increment in hours of television watching increased risk of breast cancer (OR per 1-SD: 1.15, 95% confidence interval [CI]: 1.05-1.26) and colorectal cancer (OR per 1-SD: 1.32, 95% CI: 1.16-1.49) while there was little evidence of an association for prostate cancer risk (OR per 1-SD: 0.94, 95% CI: 0.84-1.06). After adjusting for years of education, the effect estimates for television watching were attenuated (breast cancer, OR per 1-SD: 1.08, 95% CI: 0.92-1.27; colorectal cancer, OR per 1-SD: 1.08, 95% CI: 0.90-1.31). Post hoc analyses showed that years of education might have a possible confounding and mediating role in the association between television watching with breast and colorectal cancer. Consistent results were observed for each cancer site according to sex (colorectal cancer), anatomical subsites and cancer subtypes. There was little evidence of associations between genetically predicted computer use and cancer risk.

CONCLUSIONS

Our univariable analysis identified some positive associations between hours of television watching and risks of breast and colorectal cancer. However, further adjustment for additional lifestyle factors especially years of education attenuated these results. Future studies using objective measures of exposure can provide new insights into the possible role of sedentary behaviour in cancer development.

Full-Day Physical Activity and Sedentary Behaviour Levels of Typically Developing Children and Adolescents in the Middle East: A Systematic Review

Physical activity (PA) and sedentary behaviour (SB) are important components of physical behaviour associated with long-term health outcomes. Environmental and cultural factors may influence physical behaviour. To explore full day PA and SB in children and adolescents (2-18 years old) in the Middle East, a systematic literature review was performed including 183 journal articles. A wide range of PA and SB outcomes were reported, in some cases making synthesis of results difficult. As a consequence, results were generally reported narratively (MVPA time, total PA, SB time). Meta-regression of daily step count revealed females took 4600 fewer steps than males, with 3000 fewer steps on weekdays than weekends, and overweight individuals taking 2800 fewer steps/day. Steps decreased with age. Meta-regression for TV viewing time demonstrated an increase by 0.04 h per year of age. Even though environmental and cultural conditions may be different, PA and SB of children and adolescents in the Middle East were largely comparable to those of Europeans and North Americans. The wide range of data collection instruments used (both self-report questionnaire and body-worn devices) and heterogeneity of data made synthesis of reported data across studies very difficult, suggesting a need for greater standardisation of data collection methods.

Physical Activity, Sedentary Behavior, and Osteoarthritis: A Two-Sample Mendelian Randomization Analysis

Background

Sedentary behavior and physical activity are still ambiguous in their effects on osteoarthritis. We aimed to evaluate the effects of physical activity and sedentary behavior on osteoarthritis to provide a reference for the prevention of osteoarthritis.

Methods

This study was conducted in Changchun, China in 2022. We used two-sample Mendelian randomization with the SNP as an instrumental variable to investigate the effect of physical activity and sedentary behavior on osteoarthritis. In addition, a two-step Mendelian randomization method was used to test whether mediating factors (BMI, smoking, Apolipoprotein B) were involved in mediating the effects of exposure factors on osteoarthritis.

Results

TV watching was causally related to knee osteoarthritis and spine osteoarthritis, and they were positively correlated (knee osteoarthritis: OR=1.162,95 %CI: 1.027-1.315, P=0.017; spine osteoarthritis: OR=1.208,95 %CI: 1.033-1.413, P=0.018). BMI played a mediating role in the process of TV watching with knee osteoarthritis and spine osteoarthritis. ((The proportion of BMI mediating effect: knee osteoarthritis: 47.1% (95% CI: 36.7%~63.2%); spine osteoarthritis: 29.5% (95% CI: 19.3%~40.8%)). The proportion of Smoking mediating effect in the process of TV watching with spine osteoarthritis was 16.1% (95% CI: 3.7% ~ 31.6%).

Conclusion

TV watching is a potential risk factor for osteoarthritis and plays a role through modifiable factors such as BMI and smoking, therefore, interventions on these factors have the potential to reduce the burden of osteoarthritis caused by longer TV watching times.

The Relationship Between Psychological Distress and Physical Activity Is Non-linear and Differs by Domain: a Cross-Sectional Study

BACKGROUND

There is increasing evidence for the relationship between physical activity (PA), sedentary behaviour and mental health. Limited data exists on sex-specific associations. We aimed to identify associations between PA dose and domain and television time with psychological distress, including sex-stratified models.

METHODS

A total of 22,176 adults from the Melbourne Collaborative Cohort Study follow-up 2 cohort (2003-2007) participated in this cross-sectional study. Occupational, household, transport, leisure PA, hours watching television and psychological distress were assessed. Restricted cubic splines were used to examine the relationships between PA domains, television viewing time and psychological distress.

RESULTS

The relationships between PA and psychological distress were non-linear (p < 0.05) and differed by PA domain. There were dose-dependent, inverse associations between distress with transport (B[95% CI] = -0.39[-0.49, -0.30]) and leisure PA (B[95% CI] = -0.35[-0.46, -0.25]). The effect estimates for transport and leisure PA with distress were larger for women. For household domain, a U-shaped curve with an elongated tail was seen. Median PA was associated with lower distress compared with lower quantities (B[95% CI] = -0.12[-0.22, -0.03]); however, this association was not evident with increasing household PA. There were no clear associations between occupational PA and distress. Higher television viewing was associated with higher distress (B[95% CI] = 0.16[0.02, 0.30]).

CONCLUSIONS

Increasing PA and reducing television viewing may contribute to reduced psychological distress, particularly in women. Future interventions should incorporate leisure and transport PA and decrease television viewing to assess the impact on mental health.

Leisure sedentary behaviour increases the risk of venous thromboembolism: a Mendelian randomisation study

BACKGROUND

Venous thromboembolism (VTE) is a substantial contributor to the global burden of disease. Observational studies have suggested that leisure sedentary behaviours (LSB) are related to the risk of VTE; however, the causal role of LSB in VTE remains unclear.

METHODS

Using data obtained from genome-wide association studies in the UK Biobank (N = 422,218), we identified 84, 21, and 4 single nucleotide polymorphisms (SNPs) related to sedentary television (TV) watching, computer use, and driving, respectively. These SNPs were employed as instrumental variables. Summary statistics for SNP-VTE associations was obtained from the FinnGen study (5,403 cases and 130,235 controls). Two-sample Mendelian randomisation (MR) analyses were performed using inverse-variance weighted (IVW), MR-Egger,weighted median, and weighted mode approaches. Sensitivity analyses were conducted to ensure robustness of the results.

RESULTS

The main IVW approach demonstrated a positive association between the genetically predicted sedentary TV watching and the risk of VTE [odds ratio (OR):1.35, 95% confidence interval (CI):1.02-1.80, P = 0.039]. However, no significant association was observed for genetically predicted sedentary computer use or driving and VTE risk. The results from our series of sensitivity analyses, including Cochran's Q test, MR-Egger intercept test, and MR-Pleiotropy RESidual Sum and Outlier method, further supported these findings.

CONCLUSION

This study provides evidence of an association between genetically predicted sedentary TV watching and the risk of VTE. Further studies are required to elucidate the underlying causal mechanisms.

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.

Leisure time sedentary behaviour and risks of breast, colorectal, and prostate cancer: A Mendelian randomization analysis

Sedentary behaviours have been associated with increased risks of some common cancers in epidemiological studies; however, it is unclear if these associations are causal. We examined potential causal associations between self-reported leisure television watching and computer use and risks of breast, colorectal, and prostate cancer using a two-sample Mendelian randomization framework. Genetic variants were identified from a recent genome-wide association study (GWAS). Cancer data were obtained from cancer GWAS consortia. Additional sensitivity analyses were applied to examine the robustness of the results. A 1-standard deviation increment in hours of television watching increased risk of breast (OR: 1.15, 95% confidence interval [CI]: 1.05,1.26) and colorectal cancer (OR: 1.32, 95%CI: 1.16,1.49) with little evidence of an association for prostate cancer risk. In multivariable models adjusted for years of education, the effect estimates for television watching were attenuated (breast cancer, OR: 1.08, 95%CI: 0.92,1.27; colorectal cancer, OR: 1.08, 95%CI: 0.90,1.31). Post-hoc analyses showed that years of education might have a possible confounding and mediating role in the association between television watching with breast and colorectal cancer. Consistent results were observed by sex (colorectal cancer), anatomical subsites, and cancer subtypes. There was little evidence of associations between computer use and cancer risk. We found evidence of positive associations between hours of television watching and risks of breast and colorectal cancer. However, these findings should be interpreted cautiously given the complex role of education. Future studies using objective measures of exposure can provide new insights into the possible role of sedentary behaviour in cancer development.

Novelty and impact

Evidence from observational studies that examined associations between sedentary behaviours and common cancers is mixed and causality is uncertain. In our Mendelian randomization analyses, higher levels of leisure television watching were found to increase the risks of breast and colorectal cancer, suggesting that the that the promotion of lowering sedentary behaviour time could be an effective strategy in the primary prevention of these commonly diagnosed cancers.

Article category

Cancer Epidemiology.

Potential causal association between leisure sedentary behaviors, physical activity and musculoskeletal health: A Mendelian randomization study

BACKGROUND

Increasing evidence shows that leisure sedentary behaviors (LSB) and physical activity (PA) are associated with various musculoskeletal disorders. However, the causality between LSB/PA and musculoskeletal health remained unknown. In this study, we aimed to evaluate the causal relationships between LSB/PA and lower back pain (LBP), intervertebral disc disorder (IVDD), rheumatoid arthritis (RA), and bone mineral density (BMD) by using a two-sample Mendelian randomization method.

METHODS

The exposure data were obtained from large-scale genome-wide association studies (GWAS), including the PA dataset (self-reported PA, n  =  377,234; accelerometer-assessed PA, n  = 91,084) and LSB dataset (n  =  422,218). The outcome data were derived from the FinnGen LBP dataset (n  =  248,528), FinnGen IVDD dataset (n  =  256,896), BMD GWAS dataset (n  =  56,284), and RA GWAS dataset (n  =  58,284). The causal relationships were estimated with inverse variance weighted (IVW), MR-Egger, and weighted median methods. Sensitivity analyses were performed with Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis to estimate the robustness of our findings.

RESULTS

Genetically predicted leisure television watching increased the risk of LBP (OR = 1.68, 95% CI 1.41 to 2.01; P = 8.23×10-9) and IVDD (OR  =  1.62, 95% CI 1.37 to 1.91; P  =  2.13 × 10-8). In addition, this study revealed a potential causal relationship between computer use and a reduced risk of IVDD (OR  = 0.60, 95% CI 0.42 to 0.86; P  =  0.005) and RA (OR  = 0.28, 95% CI 0.13 to 0.60; P  =  0.001).

CONCLUSIONS

Our results suggest that leisure television watching is a risk factor for LBP and IVDD, whereas leisure computer use may act as a protective factor against IVDD and RA. These findings emphasized the importance of distinguishing between different sedentary behaviors in musculoskeletal disease studies.

Organized Youth Sports Trajectories and Adult Health Outcomes: The Young Finns Study

INTRODUCTION

This study identified the trajectories of organized youth sports over 9 years in youths aged 9-18 years and examined whether the trajectories predicted physical activity, sedentary behavior, and obesity in midlife.

METHODS

Self-reported organized youth sports trajectories were identified for participants between 1980 and 1989 (N=3,474). Accelerometer-derived physical activity was quantified for participants (n=1,349) in 2018-2020. Sociodemographic, physical activity, and TV viewing data were collected through questionnaires either at baselines or follow-up. Adult BMI was calculated to clarify obesity. Associations of organized youth sports trajectories with adult physical activity, sedentary behavior, and obesity were evaluated using mixture models, which were stratified by sex and conducted in 2022.

RESULTS

Three organized youth sports trajectories were identified for boys and girls (sustained high-sports participation, 12.0%/7.5%; sustained moderate-sports participation, 14.0%/13.3%; and low-sports/nonparticipation, 74.0%/79.2%). Boys sustaining both moderate- and high-sports participation had higher levels of adult self-reported physical activity (β=0.59, p=0.007; β=0.69, p<0.001) than low-sports/nonparticipating boys. Girls sustaining both moderate- and high-sports participation accumulated more total physical activity (β=113.4, p=0.009; β=144.3, p=0.002), moderate-to-vigorous physical activity (β=7.86, p=0.016; β=14.01, p<0.001), step counts (β=1,020, p=0.003; β=1,045, p=0.005), and self-reported physical activity (β=0.79, p<0001; β=0.63, p=0.003) in midlife than their low-sports/nonparticipating counterparts. Girls sustaining moderate-sports participation accumulated more light-intensity physical activity (β=19.79, p=0.012) and less sedentary time (β= -27.65, p=0.002), and those sustaining high-sports participation had lower obesity prevalence (OR=0.41, p=0.009) 40 years later than low-sports/nonparticipating girls.

CONCLUSIONS

Sustained participation in organized youth sports is independently predictive of physical activity patterns, sedentary time, and obesity in midlife, especially in girls, thus contributing to the development of a healthy and active lifestyle across the life course.

Total Sedentary Time and Cognitive Function in Middle-Aged and Older Adults: A Systematic Review and Meta-analysis

Background

An estimated 47 million people have dementia globally, and around 10 million new cases are diagnosed each year. Many lifestyle factors have been linked to cognitive impairment; one emerging modifiable lifestyle factor is sedentary time.

Objective

To conduct a systematic review and meta-analysis of peer-reviewed literature examining the association between total sedentary time with cognitive function in middle-aged and older adults under the moderating conditions of (a) type of sedentary time measurement; (b) the cognitive domain being assessed; (c) looking at sedentary time using categorical variables (i.e., high versus low sedentary time); and (d) the pattern of sedentary time accumulation (e.g., longer versus shorter bouts). We also aimed to examine the prevalence of sedentary time in healthy versus cognitively impaired populations and to explore how experimental studies reducing or breaking up sedentary time affect cognitive function. Lastly, we aimed to conduct a quantitative pooled analysis of all individual studies through meta-analysis procedures to derive conclusions about these relationships.

Methods

Eight electronic databases (EMBASE; Web of Science; PsycINFO; CINAHL; SciELO; SPORTDiscus; PubMed; and Scopus) were searched from inception to February 2021. Our search included terms related to the exposure (i.e., sedentary time), the population (i.e., middle-aged and older adults), and the outcome of interest (i.e., cognitive function). PICOS framework used middle-aged and older adults where there was an intervention or exposure of any sedentary time compared to any or no comparison, where cognitive function and/or cognitive impairment was measured, and all types of quantitative, empirical, observational data published in any year were included that were published in English. Risk of bias was assessed using QualSyst.

Results

Fifty-three studies including 83,137 participants met the inclusion criteria of which 23 studies had appropriate data for inclusion in the main meta-analysis. The overall meta-analysis suggested that total sedentary time has no association with cognitive function (r = −0.012 [95% CI − 0.035, 0.011], p = 0.296) with marked heterogeneity (I² = 89%). Subgroup analyses demonstrated a significant negative association for studies using a device to capture sedentary time r = −0.035 [95% CI − 0.063, − 0.008], p = 0.012). Specifically, the domains of global cognitive function (r = −0.061 [95% CI − 0.100, − 0.022], p = 0.002) and processing speed (r = −0.067, [95% CI − 0.103, − 0.030], p < 0.001). A significant positive association was found for studies using self-report (r = 0.037 [95% CI − 0.019, 0.054], p < 0.001). Specifically, the domain of processing speed showed a significant positive association (r = 0.057 [95% CI 0.045, 0.069], p < 0.001). For prevalence, populations diagnosed with cognitive impairment spent significantly more time sedentary compared to populations with no known cognitive impairments (standard difference in mean = −0.219 [95% CI − 0.310, − 0.128], p < 0.001).

Conclusions

The association of total sedentary time with cognitive function is weak and varies based on measurement of sedentary time and domain being assessed. Future research is needed to better categorize domains of sedentary behaviour with both a validated self-report and device-based measure in order to improve the strength of this relationship. PROSPERO registration number: CRD42018082384.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00507-x.

Rapid cycle adaptation of a classroom-based intervention to promote equity in access to youth physical activity

Our objective was to systematically adapt Interrupting Prolonged sitting with ACTivity (InPACT), a classroom-based physical activity intervention, for home delivery to equitably increase access to structured youth physical activity opportunities during the COVID-19 pandemic. Key steps in the rapid-cycle research adaptation process included: (Step 1) identifying partner organizations; (Steps 2 and 3) engaging in problem and knowledge exploration to examine the problem from different perspectives; (Steps 4 and 5) initiating solution development and testing by selecting an intervention and adapting the format and content for home delivery. Using Rapid RE-AIM to guide online assessment and refinement of InPACT at Home; and (Step 6) utilizing dissemination strategies to extend the reach of the program. Core elements of the InPACT program that were retained included: the use of exercise videos, maintenance of the intervention dose, and teacher-led physical activities. Key adaptations included: utilization of physical education specialists to develop the exercise videos, incorporation of health messaging in videos, and utilization of dissemination strategies (intervention website) to reach K-12 students across the state. Intervention website reach included all 83 counties in Michigan, but goals were not met for website pageviews (5,147; 85% of goal) and video view duration (7 min 19 sec; 37% of goal). Accordingly, dissemination was expanded to include public television broadcasting (monthly viewers: 500,000) and videos were shortened to 8 minutes. Dissemination and implementation science frameworks guided the rapid adaptation of an existing intervention, InPACT, to equitably increase access to structured youth physical activity opportunities at home during the pandemic.

An invisible villain: high perceived stress, its associated factors, and possible consequences in a population-based survey in southern Brazil

INTRODUCTION

Much of the evidence on the relationship between stress, lifestyle, and other physical and mental health outcomes comes from studies conducted in high-income countries. There is therefore a need for research among populations in low and middle-income settings.

OBJECTIVES

To measure stress levels and identify factors associated with a high stress level and its consequences for health.

METHODS

This was a population-based cross-sectional study carried out in 2016 with adults aged 18 years or older in a municipality in southern Brazil. A two-stage sampling strategy based on census tracts was used. Stress levels were measured with the Perceived Stress Scale (PSS-14) and classified into quartiles. The impact of the highest stress levelon each outcome was assessed with etiologic fractions (EF).

RESULTS

The most stressed groups were: females (PR = 1.51, 95%CI 1.25-1.81), younger people (PR = 1.76, 95%CI 1.26-2.46), middle-aged individuals (PR = 1.60, 95%CI 1.17-2.19), those with lower schooling (PR = 1.56, 95%CI 1.20-2.02), the physically inactive (PR = 1.51, 95%CI 1.20-1.91), people who spent three or more hours watching television per day (PR = 1.29, 95%CI 1.12-1.50), and those with food insecurity (PR = 1.44, 95%CI 1.19-175). Possible consequences of high stress level were regular or poor self-perception of health (EF = 29.6%), poor or very poor sleep quality (EF = 17.3%), lower quality of life (EF = 45.6%), sadness (EF = 24.2%), and depressive symptoms (EF = 35.8%).

CONCLUSIONS

Stress plays an important role in several domains of health. Both public policies that target reduction of inequalities and specific stress-management interventions can reduce stress levels in populations, thereby decreasing the burden of other negative physical and mental health outcomes related to stress.

Redevelopment and Examination of the Psychometric Properties of the Chinese Version of the Last 7-Day Sedentary Behaviour Questionnaire (SIT-Q-7d-Chi) in Hong Kong Older Adults

(1) Background: This study examined the psychometric properties of the Chinese version of the Last 7-Day Sedentary Behaviour Questionnaire (SIT-Q-7d-Chi) in Hong Kong older adults; (2) Methods: Study 1 assessed the questionnaire’s test–retest reliability, and Study 2 examined its validity. Place the question addressed in a broad context and highlight the purpose of the study; (3) Results: In Study 1, 84 older adults (aged 60–90) completed the SIT-Q-7d-Chi twice over a 2-week interval, and in Study 2, 38 older adults (i) completed the SIT-Q-7d-Chi and the Sedentary Behaviour Questionnaire for Older Adults (SBQOA) and (ii) wore a waist-mounted accelerometer for 7 consecutive days. In Study 1, the SIT-Q-7d-Chi’s test–retest reliability (ICC = 0.91–0.99) was satisfactory, and adequate internal consistency was found for most domains of the SIT-Q-7d-Chi (Cronbach’s alpha value being 0.7 or above). Study 2′s results showed that the SIT-Q-7d-Chi results were significantly correlated with the SBQOA results, but not with the accelerometer results; (4) Conclusions: This study revealed the prevalence of sedentary behavior among Hong Kong’s senior citizens, which can be used as a reference to plan or evaluate a future sedentary behavior intervention for older persons, including identifying the content and intensity of activities.

Causal relationship between physical activity, leisure sedentary behaviors and COVID-19 risk: a Mendelian randomization study

BACKGROUND

The 2019 coronavirus disease pandemic (COVID-19) poses an enormous threat to public health worldwide, and the ensuing management of social isolation has greatly decreased opportunities for physical activity (PA) and increased opportunities for leisure sedentary behaviors (LSB). Given that both PA and LSB have been established as major influencing factors for obesity, diabetes and cardiometabolic syndrome, whether PA/LSB in turn affects the susceptibility to COVID-19 by disrupting metabolic homeostasis remains to be explored. In this study, we aimed to systematically evaluate the causal relationship between PA/LSB and COVID-19 susceptibility, hospitalization and severity using a Mendelian randomization study.

METHODS

Data were obtained from a large-scale PA dataset (N = 377,000), LSB dataset (N = 422,218) and COVID-19 Host Genetics Initiative (N = 2,586,691). The causal effects were estimated with inverse variance weighted, MR-Egger, weighted median and MR-PRESSO. Sensitivity analyses were implemented with Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis and the funnel plot. Risk factor analyses were further conducted to investigate the potential mediators.

RESULTS

Genetically predicted accelerometer-assessed PA decreased the risk for COVID-19 hospitalization (OR = 0.93, 95% CI 0.88-0.97; P = 0.002), while leisure television watching significantly increased the risk of COVID-19 hospitalization (OR = 1.55, 95% CI 1.29-1.88; P = 4.68 × 10-6) and disease severity (OR = 1.85, 95% CI 1.33-2.56; P = 0.0002) after Bonferroni correction. No causal effects of self-reported moderate to vigorous physical activity (MVPA), accelerometer fraction of accelerations > 425 milligravities, computer use or driving on COVID-19 progression were observed. Risk factor analyses indicated that the above causal associations might be mediated by several metabolic risk factors, including smoking, high body mass index, elevated serum triglyceride levels, insulin resistance and the occurrence of type 2 diabetes.

CONCLUSION

Our findings supported a causal effect of accelerometer-assessed PA on the reduced risk of COVID-19 hospitalization as well as television watching on the increased risk of COVID-19 hospitalization and severity, which was potentially mediated by smoking, obesity and type 2 diabetes-related phenotypes. Particular attention should be given to reducing leisure sedentary behaviors and encouraging proper exercise during isolation and quarantine for COVID-19.

Physical activity, sedentary behaviour and incidence of obstructive sleep apnoea in three prospective US cohorts

BACKGROUND

Reduced physical activity and increased sedentary behaviour may independently contribute to the development of obstructive sleep apnoea (OSA) through increased adiposity, inflammation, insulin resistance and body fluid retention. However, epidemiological evidence remains sparse and is primarily limited to cross-sectional studies.

METHODS

We prospectively followed 50 332 women from the Nurses' Health Study (2002-2012), 68 265 women from the Nurses' Health Study II (1995-2013) and 19 320 men from the Health Professionals Follow-up Study (1996-2012). Recreational physical activity (quantified by metabolic equivalent of task (MET)-h per week) and sitting time spent watching TV and at work/away from home were assessed by questionnaires every 2-4 years. Physician-diagnosed OSA was identified by validated self-report. Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals for OSA incidence associated with physical activity and sedentary behaviour.

RESULTS

During 2 004 663 person-years of follow-up, we documented 8733 incident OSA cases. After adjusting for potential confounders, the pooled HR for OSA comparing participants with ≥36.0 versus <6.0 MET-h per week of physical activity was 0.46 (95% CI 0.43-0.50; p_trend<0.001). Compared with participants spending <4.0 h per week sitting watching TV, the multivariable-adjusted HR was 1.78 (95% CI 1.60-1.98) for participants spending ≥28.0 h per week (p_trend<0.001). The comparable HR was 1.49 (95% CI 1.38-1.62) for sitting hours at work/away from home (p_trend<0.001). With additional adjustment for several metabolic factors, including body mass index and waist circumference, the associations with physical activity and sitting hours at work/away from home were attenuated but remained significant (p_trend<0.001), whereas the association with sitting hours watching TV was no longer statistically significant (p_trend=0.18).

CONCLUSIONS

Higher levels of physical activity and fewer sedentary hours were associated with lower OSA incidence. The potential mediating role of metabolic factors in the association between sedentary behaviour and OSA incidence may depend on the type of sedentary behaviour. Our results suggest that promoting an active lifestyle may reduce OSA incidence.

Leisure Sedentary Behavior and Risk of Lung Cancer: A Two-Sample Mendelian Randomization Study and Mediation Analysis

Leisure sedentary behavior, especially television watching, has been previously reported as associated with the risk of lung cancer in observational studies. This study aims to evaluate the causal association with two-sample Mendelian randomization (MR) analysis. Single nucleotide polymorphisms associated with leisure television watching, computer use, and driving were extracted from genome-wide association studies. Summary-level results of lung cancer overall and histological types were obtained from International Lung Cancer Consortium (ILCCO). In univariable MR using inverse-variance-weighted method, we observed causal effects of television watching on lung cancer [OR, 1.89, 95% confidence interval (CI), 1.41, 2.54; p = 2.33 × 10-5], and squamous cell lung cancer (OR, 2.37, 95% CI, 1.58, 3.55; p = 3.02 × 10-5), but not on lung adenocarcinoma (OR, 1.40, 95% CI, 0.94, 2.09; p = 0.100). No causal effects of computer use and driving on lung cancer were observed. Television watching significantly increased the exposure to several common risk factors of lung cancer. The associations of television watching with lung cancer and squamous cell lung cancer were compromised after adjusting for smoking quantity with multivariable MR. Our mediation analyses estimated indirect effects of television watching on lung cancer (beta, 0.31, 95% CI, 0.13, 0.52; p = 6.64 × 10-4) and squamous cell lung cancer (beta, 0.33, 95% CI, 0.14, 0.53, p = 4.76 × 10-4) mediated by smoking quantity. Our findings indicate that television watching is positively correlated with the risk of lung cancer, potentially mediated through affecting smoking quantity.

The Prediction of Running Velocity during the 30-15 Intermittent Fitness Test Using Accelerometry-Derived Metrics and Physiological Parameters: A Machine Learning Approach

Measuring exercise variables is one of the most important points to consider to maximize physiological adaptations. High-intensity interval training (HIIT) is a useful method to improve both cardiovascular and neuromuscular performance. The 30–15_IFT is a field test reflecting the effort elicited by HIIT, and the final velocity reached in the test is used to set the intensity of HIIT during the training session. In order to have a valid measure of the velocity during training, devices such as GPS can be used. However, in several situations (e.g., indoor setting), such devices do not provide reliable measures. The aim of the study was to predict exact running velocity during the 30–15_IFT using accelerometry-derived metrics (i.e., Player Load and Average Net Force) and heart rate (HR) through a machine learning (ML) approach (i.e., Support Vector Machine) with a leave-one-subject-out cross-validation. The SVM approach showed the highest performance to predict running velocity (r = 0.91) when compared to univariate approaches using PL (r = 0.62), AvNetForce (r = 0.73) and HR only (r = 0.87). In conclusion, the presented multivariate ML approach is able to predict running velocity better than univariate ones, and the model is generalizable across subjects.

Television Viewing, Physical Activity, and Loneliness in Late Life

BACKGROUND AND OBJECTIVES

Television viewing is the most common leisure activity in late life and may ease loneliness but encourage sedentary behavior. These associations may be particularly evident among older adults who live alone and who may lack other forms of companionship throughout the day.

RESEARCH DESIGN AND METHODS

Adults aged 65+ (N = 257) participated, of whom 34% lived alone. Participants completed an initial interview followed by a 5- to 6-day data collection involving multi-methods: (a) Electronically Activated Recorders (EAR) (30 seconds every 7 minutes) provided audio recordings of television viewing, (b) Actical accelerometers objectively measured physical activity, and (c) ecological momentary assessments (EMA) every 3 hours assessed social interactions.

RESULTS

On average, older adults spent approximately 37% of their waking time (6.4 hours a day) watching television. Multilevel models revealed that television viewing occurred when participants were alone or with a spouse and was associated with a greater proportion of time sedentary, lower activity, and higher ratings of loneliness compared to when not watching television. Older adults who lived alone reported greater loneliness during 3-hour intervals when viewing television, but older adults who lived with others spent a greater proportion of time sedentary when viewing television.

DISCUSSION AND IMPLICATIONS

Findings are discussed with regard to different rationales and ways of watching television - as compensation for social isolation or as a passive leisure activity with a social partner. We discuss ideas for research on additional aspects of television viewing and screen time in late life.

Patterns of Change in Device-Based Physical Activity and Sedentary Time Following Bariatric Surgery: a Longitudinal Observational Study

PURPOSE

The aim of this study is to investigate changes in physical activity (PA) and sedentary time (ST) over 12 months following bariatric surgery.

METHODS

Pre-surgery and at 3, 6, 9, and 12 months post-surgery, wearable devices were used to measure PA at different intensities, grouped according to energy expenditure and daily step count, and ST. Measures were also collected of weight and self-efficacy for exercise. Pre- and 12 months post-surgery, measures were collected of body composition and cardiovascular fitness.

RESULTS

Thirty adults scheduled for bariatric surgery were recruited (20 females, 44.1 [range, 22.0 to 65.0] years, body mass index 39.6 [range, 30.9 to 50.9] kg/m²). When compared to pre-surgery measures, over the 12 months post-surgery, there were no changes in the percentage of waking hours (mean [95% CI]) spent in ST (- 2% [- 6 to 3]), light intensity PA (1% [- 3 to 5]), and moderate-to-vigorous intensity PA (1% [- 1 to 3]). At all time points, participants spent most (> 70%) of their waking hours accumulating ST, with little time spent in light intensity PA (~ 21%) and almost no time in moderate-to-vigorous intensity PA (~ 5%). Step count and cardiovascular fitness were also unchanged. There were significant changes in weight, self-efficacy for exercise, and body composition.

CONCLUSIONS

Although bariatric surgery resulted in substantial weight loss and improved self-efficacy for exercise, it was insufficient to effect change in PA, ST or cardiovascular fitness. Complementing surgical intervention with behavioral interventions may optimize change in PA and ST.

Objective and subjective measurement of sedentary behavior in human adults: A toolkit

OBJECTIVES

Objectives: Human biologists are increasingly interested in measuring and comparing physical activities in different societies. Sedentary behavior, which refers to time spent sitting or lying down while awake, is a large component of daily 24 hours movement patterns in humans and has been linked to poor health outcomes such as risk of all-cause and cardiovascular mortality, independently of physical activity. As such, it is important for researchers, with the aim of measuring human movement patterns, to most effectively use resources available to them to capture sedentary behavior.

METHODS

This toolkit outlines objective (device-based) and subjective (self-report) methods for measuring sedentary behavior in free-living contexts, the benefits and drawbacks to each, as well as novel options for combined use to maximize scientific rigor. Throughout this toolkit, emphasis is placed on considerations for the use of these methods in various field conditions and in varying cultural contexts.

RESULTS

Objective measures such as inclinometers are the gold-standard for measuring total sedentary time but they typically cannot capture contextual information or determine which specific behaviors are taking place. Subjective measures such as questionnaires and 24 hours-recall methods can provide measurements of time spent in specific sedentary behaviors but are subject to measurement error and response bias.

CONCLUSIONS

We recommend that researchers use the method(s) that suit the research question; inclinometers are recommended for the measurement of total sedentary time, while self-report methods are recommended for measuring time spent in particular contexts of sedentary behavior.

Objectively measured sedentary time, physical activity and liver enzyme elevations in US Hispanics/Latinos

BACKGROUND & AIMS

Sedentariness and physical inactiveness are associated with deleterious health outcomes, but their associations with liver enzyme elevations remain uncertain.

METHODS

In 10 385 US Hispanics/Latinos from the Hispanic Community Health Study/Study of Latinos, we examined associations of sedentary time and moderate-to-vigorous physical activity (MVPA) measured by accelerometers with liver enzyme elevations. Elevated alanine aminotransferase (ALT), aspartate aminotransferase and γ-glutamyltransferase (GGT) were defined as the highest gender-specific deciles. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were calculated using weighted Poisson regressions.

RESULTS

After adjusting for demographical/socioeconomic factors and MVPA, increasing quartiles of sedentary time were associated with a higher prevalence of elevated ALT (PRs [95% CI] = 1.0, 1.17 [0.92-1.47], 1.21 [0.96, 1.53] and 1.51 [1.13-2.02]; P-trend = .007) and elevated GGT (PRs [95% CI] = 1.0, 1.06 [0.82-1.36], 1.35 [1.06-1.73] and 1.66 [1.27-2.16]; P-trend = .0001). These associations were attenuated but remained significant after further adjustment for cardiometabolic traits including body-mass index, waist-hip-ratio, lipids and homeostatic model assessment of insulin resistance. In contrast, increasing quartiles of MVPA were associated with a lower prevalence of elevated ALT (PRs [95% CI] =1.0, 0.97 [0.77-1.23], 0.84 [0.66-1.06] and 0.72 [0.54-0.96]; P-trend = .01) after adjusting for demographical/socioeconomic factors and sedentary time, but this association became non-significant after further adjustment for cardiometabolic traits. Notably, the association of sedentary time with GGT elevation was significant both in individuals meeting the US Physical Activity Guidelines for Americans (MVPA ≥150 minutes/week) and in those who did not (both P-trend ≤ .003).

CONCLUSIONS

Our findings suggest that objectively measured sedentary time is independently associated with elevated ALT and GGT in US Hispanics/Latinos.

Main and interacting effects of physical activity and sedentary time on older adults' BMI: The moderating roles of socio-demographic and environmental attributes

Objectives

Our first aim was to examine the main and interacting effects of accelerometer-based sedentary time (ST) and moderate-to-vigorous physical activity (MVPA) with BMI and the likelihood of being overweight/obese in Hong Kong and Ghent (Belgium) older adults. Second, we examined whether these main associations and interactions between MVPA and ST were moderated by socio-demographics (gender, education) and objective neighbourhood attributes supposed to be associated with healthy food intake (food outlet density, neighbourhood-level SES). Finally, we determined whether the associations and interactions were generalisable across study sites.

Methods

Data from the ALECS (Hong Kong) and BEPAS Seniors studies (Ghent), two comparable observational studies, were used. Older adults (n = 829, 65+) provided self-reported socio-demographic information and objective MVPA and ST data using Actigraph accelerometers. Annual household income data and GIS software were used to assess neighbourhood-level SES and food outlet density. Generalised additive mixed models were conducted in R.

Results

ST was linearly and positively related to both weight outcomes in the overall sample, while MVPA was not. The overall-sample analyses including the two-way interaction between MVPA and ST showed no interactions between these behaviours on weight outcomes. Three site-specific findings were identified, showing distinct associations in Hong Kong compared to Ghent. Study site moderated the interaction between ST and MVPA on both weight outcomes, the interaction between education and ST on both weight outcomes and the interaction between the number of food outlets and ST on being overweight/obese.

Conclusions

The country-specific effects confirm the cultural dependency and complexity of the associations between PA, ST and weight outcomes. Future longitudinal international studies including older adults from multiple regions assessing PA, ST, weight outcomes and dietary intake should be encouraged. Such studies are needed to refine the recommendations regarding ST and PA in older adults in light of preventing overweight and obesity.

Antihypertensive medications and physical function in older persons

BACKGROUND

To further inform benefits and risks of medications on physical function in aging populations, we have evaluated the associations of antihypertensive (antiHTN) class and number used with skeletal muscle function, mobility, sedentary time, and symptoms in older persons.

METHODS

Using baseline data from the Lifestyle Interventions and Independence in Elder (LIFE) study (N = 1567, mean age 78.9 years) and multivariable models, we evaluated cross-sectional associations of antiHTN class and number used with physical measures and symptom questionnaires. AntiHTN class included diuretics, angiotensin converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), calcium channel blockers (CCB), and beta blockers (BB). Physical measures included respiratory muscle weakness (maximal inspiratory pressure), grip weakness (dynamometer), impaired lower extremity proximal muscle strength (chair stands), impaired balance (three-stage test), slow gait (400 m walk), mobility impairment (Short Physical Performance Battery), and high sedentary time (accelerometry). Symptoms included dyspnea and fatigue. Covariates included clinical characteristics and non-antiHTNs.

RESULTS

Use of any antiHTN was highly prevalent (n = 1248 [79.6%]). In the antiHTN subgroup, each antiHTN class was well represented (ranging 36.6%-62.7%) and included use of three or more antiHTNs (32.0%). In adjusted models, the only statistically significant associations were use of BB and three or more antiHTNs with high sedentary time: odds ratios (95% confidence intervals) 1.44 (1.12, 1.85) and 1.52 (1.04, 2.23), respectively.

CONCLUSION

Use of BB and three or more antiHTNs yielded 44% and 52% increased odds of accelerometry-defined high sedentary time, respectively. Notably, high sedentary time is a risk factor for adverse health outcomes. Thus, future work should evaluate whether high sedentary time mitigates benefits or increases risks, regarding antiHTN use in aging populations.

The Length and Number of Sedentary Bouts Predict Fibrinogen Levels in Postmenopausal Women

Menopause is associated with adverse changes in coagulation homeostasis. We aimed to investigate the association between objectively measured sedentary behavior (SB) and SB bouts (i.e., number and length of SB bouts) vs. fibrinogen levels in post-menopausal women. Fifty-three post-menopausal women (age 59.8 ± 6.2 years, BMI 27.3 ± 4.4) wore a multisensory device (Sensewear Mini Armband, BodyMedia, Inc., Pittsburgh, PA) for 5 days, to measure SB and physical activity (PA). Blood samples were collected to measure serum fibrinogen. Fibrinogen was directly correlated with SB (r = −0.48, p < 0.01), lying down during awake time (r = −0.50, p < 0.01), and both medium (11–30 mins) and very long bouts (>1 h) of SB (r = −0.59, p < 0.01; r = −0.51, p < 0.01, respectively), and inversely correlated with moderate to vigorous-intensity physical activity (r = −0.39, p < 0.01). Furthermore, fibrinogen was also directly correlated with BMI (r = −0.28, p < 0.05). In postmenopausal women without prevalent cardiovascular disease, the number of prolonged and uninterrupted sedentary bouts is directly correlated with increased fibrinogen levels, regardless of PA and BMI. This result suggests the importance of delivering new strategies to counteract the increase of sedentariness and inactivity of the postmenopausal population.

Genome-wide association studies and Mendelian randomization analyses for leisure sedentary behaviours

Leisure sedentary behaviours are associated with increased risk of cardiovascular disease, but whether this relationship is causal is unknown. The aim of this study is to identify genetic determinants associated with leisure sedentary behaviours and to estimate the potential causal effect on coronary artery disease (CAD). Genome wide association analyses of leisure television watching, leisure computer use and driving behaviour in the UK Biobank identify 145, 36 and 4 genetic loci (P < 1×10-8), respectively. High genetic correlations are observed between sedentary behaviours and neurological traits, including education and body mass index (BMI). Two-sample Mendelian randomization (MR) analysis estimates a causal effect between 1.5 hour increase in television watching and CAD (OR 1.44, 95%CI 1.25-1.66, P = 5.63 × 10-07), that is partially independent of education and BMI in multivariable MR analyses. This study finds independent observational and genetic support for the hypothesis that increased sedentary behaviour by leisure television watching is a risk factor for CAD.

Associations Between Television Time and activPAL-Measured Duration and Pattern of Sedentary Time Among Pregnant Women at Risk of Gestational Diabetes in the UK

BACKGROUND

Television (TV) time is associated with poor cardiometabolic health outcomes. This finding is commonly attributed to duration of sitting or patterns of sitting associated with high TV time, but there is very little evidence on this link.

METHODS

Pregnant women (n = 167) at risk of gestational diabetes wore an activPAL accelerometer and self-reported their usual TV time in the second trimester. Generalized linear mixed models were used to compare objectively measured total sedentary time (ST), prolonged ST (bouts ≥30 min), and breaks in ST for all hours and evening hours (6 PM-11 PM) between those with high (≥2 h/d) and low TV time.

RESULTS

Over all waking hours, those with high TV time had fewer breaks in ST than those with low TV time, exp(b) 0.92; 95% confidence interval, 0.86 to 0.998; there were no differences in total ST or prolonged ST between the 2 groups. Those with high TV time had significantly higher evening ST (b = 9.9; 95% confidence interval, 0.5 to 19.2); there were no differences in prolonged ST or breaks in ST during evening hours.

CONCLUSIONS

These findings suggest that high TV time may be associated with higher evening ST and fewer breaks in ST. The link between TV time and sitting patterns requires further investigation.

Time Spent Sitting as an Independent Risk Factor for Cardiovascular Disease

Sedentary behavior is highly prevalent despite growing evidence of adverse effects on the cardiovascular and metabolic system that are independent of the level of recreational physical activity (PA). We present results for the association between sitting time and cardiovascular disease (CVD) from selected cohort and cross-sectional studies published in or after the year 2010 according to the domains where sitting time is accumulated during the day. These include TV viewing, occupational sitting, and sitting during transportation as well as overall sitting. The outcomes considered in this review are total CVD, coronary heart disease, and stroke as well as CVD risk factors-namely, hypertension, hypercholesterolemia, and type 2 diabetes and their associated biomarkers. Finally, several current issues with regard to studying the effects of sitting time on CVD are discussed, including how sedentary behavior is assessed, isotemporal substitution modeling, examination of joint associations for sitting and PA, and benefits of breaks in sitting time. Overall, the scientific evidence supports public health recommendations that encourage adults to limit their sedentary time in order to improve their cardiovascular health.

Correlates of Total and domain-specific Sedentary behavior: a cross-sectional study in Dutch adults

Background

Sedentary behavior (SB) is associated with increased risks of detrimental health outcomes. Few studies have explored correlates of SB in physically active individuals. Furthermore, SB correlates may depend on settings of SB, such as occupation, transportation and leisure time sitting. This study aims to identify subject-, lifestyle- and health-related correlates for total SB and different SB domains: transportation, occupation, and leisure time.

Methods

Dutch participants were recruited between June, 2015 and December, 2016. Participant characteristics (i.e. age, sex, weight, height, marital status, education level, employment), lifestyle (sleep, smoking, alcohol consumption, physical activity) and medical history were collected via an online questionnaire. SB was assessed using the Sedentary Behavior Questionnaire and estimated for 9 different activities during weekdays and weekend days. Logistic regression was used to calculate odds ratios and 95% confidence intervals for the association between correlates and SB. Total SB was dichotomized at > 8 h/day and > 10 h/day, and being sedentary during transportation, occupation and leisure time at the 75th percentile (60 min/day, 275 min/day and 410 min/day, respectively).

Results

In total, 8471 participants (median age 55, 55% men) were included of whom 86% met the physical activity guidelines. Median SB was 9.1 h/day (Q₂₅ 6.3-Q₇₅ 12.0) during weekdays and 7.4 h/day (Q₂₅ 5.5-Q₇₅ 9.5) during weekend days. SB was most prevalent during leisure time (5.3 h/day; Q₂₅ 3.9-Q₇₅ 6.8), followed by occupation (2 h/day; Q₂₅ 0.1-Q₇₅ 4.6) and transportation (0.5 h/day; Q₂₅ 0.2-Q₇₅ 1.0). Younger age, male sex, being unmarried, higher education, employment and higher BMI were significantly related to higher levels of total SB. Younger age, male sex, employment, and higher BMI increased the odds for high SB volumes during occupation and transportation. Higher education, being unmarried and smoking status were positively associated with high volumes of occupational SB only, whereas older age, being unmarried, unemployment, higher BMI and poor health were positively linked to leisure time SB.

Conclusions

SB is highly prevalent in physically active individuals, with SB during leisure time as the most important contributor. Correlates for high volumes of SB vary substantially across SB domains, emphasizing the difficulty to target this unhealthy lifestyle.

Types of Sedentary Behavior and Risk of Cardiovascular Events and Mortality in Blacks: The Jackson Heart Study

Background

Previous cross‐sectional studies have shown conflicting results regarding the effects of television viewing and occupational sitting on cardiovascular disease (CVD) risk factors. The purpose of this study was to compare the association of both television viewing and occupational sitting with CVD events and all‐cause mortality in blacks.

Methods and Results

Participants included 3592 individuals enrolled in the Jackson Heart Study, a community‐based study of blacks residing in Jackson, Mississippi. Television viewing (<2, 2–4, and >4 h/day) and occupational sitting (never/seldom, sometimes, often/always) were self‐reported. Over a median follow‐up of 8.4 years, there were 129 CVD events and 205 deaths. The highest category of television viewing (>4 h/day) was associated with a greater risk for a composite CVD events/all‐cause mortality end point compared with the lowest category (<2 h/day; hazard ratio, 1.49; 95% CI, 1.13–1.97). In contrast, the highest category of occupational sitting (often/always) was not associated with risk for a composite CVD events/all‐cause mortality end point compared with the lowest category (never/seldom; hazard ratio, 0.90; 95% CI, 0.69–1.18). Moderate‐to‐vigorous physical activity moderated the association of television viewing with CVD events/all‐cause mortality such that television viewing was not associated with greater risk among those with high moderate‐to‐vigorous physical activity levels.

Conclusions

Television viewing was associated with greater risk of CVD events and all‐cause mortality, while occupational sitting had no association with these outcomes. These findings suggest that minimizing television viewing may be more effective for reducing CVD and mortality risk in blacks compared with reducing occupational sedentary behavior.

Perceived and objective characteristics of the neighborhood environment are associated with accelerometer-measured sedentary time and physical activity, the CARDIA Study

We investigated cross-sectional and longitudinal associations of neighborhood environment characteristics with accelerometer-measured sedentary time (SED), light-intensity physical activity (LPA), and moderate-to-vigorous intensity physical activity (MVPA). Participants were 2120 men and women in the year 20 (2005-2006) and year 30 CARDIA exams (2015-2016). Year 20 neighborhood characteristics included neighborhood cohesion, resources for physical activity, poverty, and racial residential segregation. Physical activity was measured by accelerometer at years 20 and 30. Multivariable linear regression models examined associations of standardized neighborhood measures at year 20 with SED, LPA, and MVPA assessed that year, and with 10-year changes in SED, LPA, and MVPA. Cross-sectionally, a one standard deviation (SD) increase in cohesion was associated with 4.06 less SED min/day (95% CI: -7.98, -0.15), and 4.46 more LPA min/day (95% CI: 0.88, 8.03). Each one SD increase in resources was associated with 1.19 more MVPA min/day (95% CI: 0.06, 2.31). A one SD increase in poverty was associated with 11.18 less SED min/day (95% CI: -21.16, -1.18) and 10.60 more LPA min/day (95% CI: 1.79, 19.41) among black men. No neighborhood characteristic was associated with 10-year changes in physical activity in the full sample; however, a one SD increase in cohesion was associated with a 10-year decrease of 25.44 SED min/day (95% CI: -46.73, -4.14) and an increase of 19.0 LPA min/day (95% CI, 1.89, 36.10) in black men. Characteristics of the neighborhood environment are associated with accelerometer-measured physical activity. Differences were observed by race and sex, with more robust findings observed in black men.

Longitudinal Sedentary Time Among Females Aged 17 to 23 Years

INTRODUCTION

Time spent in sedentary behaviors is a newer risk factor for poor cardiometabolic health. This study examined longitudinal correlates of sedentary time among a cohort of females from about age 17 to age 23 years.

METHODS

The cohort included females originally participating in the Trial of Activity for Adolescent Girls Maryland site who had assessments in 2009 and 2015 (n=431). Percentage daily time in sedentary behaviors was determined from accelerometers. Sociodemographics, psychosocial factors, and health behaviors were assessed by questionnaire. Lasso variable selection identified potential variables included in linear mixed effects models. As a secondary analysis, a k-means algorithm for longitudinal data identified homogeneous clusters of individual sedentary time trajectories.

RESULTS

Percentage daily sedentary time did not change over time (67% to 68%). Not of black race (p=0.04), higher father's education (p<0.001), more weekday computer hours (p<0.001), more weekend TV hours (p=0.01), more physical activity barriers (p=0.003), fewer days per week driving (p=0.01), and more vehicles in the household (p=0.02) were associated with greater sedentary time. Cluster analysis resulted in two patterns: more (70%) versus less (60%) time being sedentary. The more sedentary individuals were more likely to be college graduates (p<0.001), have a higher income (p=0.03), and work fewer hours (p=0.009). They were also less likely to be married or in a common-law relationship (p=0.05) or in a parenting role (p=0.02).

CONCLUSIONS

Time spent in sedentary behaviors remained stable. Factors associated with sedentary time were significant across the socioecologic framework and included several factors indicating higher SES.

Television Viewing Time and Breast Cancer Incidence for Japanese Premenopausal and Postmenopausal Women: The JACC Study

Purpose

The evidence on effects of TV viewing time among premenopausal and postmenopausal women for breast cancer risk remains controversial and limited.

Materials and Methods

A prospective study encompassing 33,276 (17,568 premenopausal, and 15,708 postmenopausal) women aged 40-79 years in whom TV viewing time, menstrual, and reproductive histories were determined by a self-administered questionnaire. The follow-up was from 1988 to 2009 and hazard ratios (HRs) with 95% confidence intervals (CIs) of breast cancer incidence were calculated for longer TV viewing time in reference to shorter TV viewing time by Cox proportional hazard models.

Results

During 16.8-year median follow-up, we found positive associations between TV viewing time and breast cancer incidence with a borderline significant trend among total women and a significant trend among postmenopausal women. Among total women, the multivariable HRs (95% CIs) for risk of breast cancer in reference to < 1.5 hr/day of TV viewing time were 0.89 (0.59-1.34) for 1.5 to < 3.0 hr/day, 1.19 (0.82-1.74) for 3.0 to < 4.5 hr/day, and 1.45 (0.91-2.32) for ≥ 4.5 hr/day (p for trend=0.053) and among postmenopausal women, the corresponding risk estimates were 1.10 (0.42-2.88), 2.54 (1.11-5.80), and 2.37 (0.92-6.10) (p for trend=0.009), respectively.

Conclusion

Prolonged TV viewing time was associated with increased risk of breast cancer, especially among postmenopausal women.

Lifestyle factors and visceral adipose tissue: Results from the PREDIMED-PLUS study

Background

Visceral adipose tissue (VAT) is a strong predictor of cardiometabolic health, and lifestyle factors may have a positive influence on VAT depot. This study aimed to assess the cross-sectional associations between baseline levels of physical activity (PA), sedentary behaviours (SB) and adherence to the Mediterranean diet (MedDiet) with VAT depot in older individuals with overweight/obesity and metabolic syndrome.

Methods

Baseline data of the PREDIMED-Plus study including a sample of 1,231 Caucasian men and women aged 55–75 years were used. Levels of leisure-time PA (total, light, and moderate-to-vigorous, in METs·min/day) and SB (total and TV-viewing, in h/day) were evaluated using validated questionnaires. Adherence to the MedDiet was evaluated using a 17-item energy-restricted MedDiet (erMedDiet) screener. The chair-stand test was used to estimate the muscle strength. VAT depot was assessed with DXA-CoreScan. Multivariable adjusted linear regression models were used to evaluate the association between lifestyle factors and VAT. For the statistics we had used multiadjusted linear regression models.

Results

Total leisure-time PA (100 METs·min/day: β -24.3g, -36.7;-11.9g), moderate-to-vigorous PA (β -27.8g, 95% CI -40.8;-14.8g), chair-stand test (repeat: β -11.5g, 95% CI -20.1;-2.93g) were inversely associated, and total SB (h/day: β 38.2g, 95% CI 14.7;61.7) positively associated with VAT. Light PA, TV-viewing time and adherence to an erMedDiet were not significantly associated with VAT.

Conclusions

In older adults with overweigh/obesity and metabolic syndrome, greater PA, muscle strength, and lower total SB were associated with less VAT depot. In this study, adherence to an erMedDiet was not associated with lower VAT.

Effectiveness of interventions aiming at reducing sedentary behaviour in a non-surgical population with overweight or obesity: A systematic review and meta-analysis

AIM

This systematic review and meta-analyses of randomised controlled trials (RCTs) investigated the effectiveness of interventions to reduce sedentary behaviour amongst people with overweight or obesity. Secondarily, it aimed to investigate the effectiveness of these interventions on body mass index (BMI), time spent in moderate-to-vigorous physical activity (MVPA) and health-related quality of life (HRQoL).

METHODS

A search of six databases (CENTRAL, PubMed, Embase, PEDro, CINAHL and PsycINFO) was conducted from inception to July 2018. RCTs in which sedentary behaviour was measured by accelerometry or inclinometry, with participants of any age with overweight or obesity were included. Subgroup analyses were undertaken comparing studies that included adults versus children and studies with an active component (e.g., treadmill desk, physically active breaks) versus no active component to their intervention.

RESULTS

Nine studies (n=1859) were included. Compared to the control group, the interventions significantly reduced time spent in sedentary behaviour (standardised mean difference [95% confidence interval] -0.33 [-0.59 to -0.08] overall; -0.53 [-0.95 to -0.11] in adults). Subgroup analyses demonstrated that only interventions that included active components reduced time spent in sedentary behaviour (-0.54 [-0.88 to -0.20]) and increased time spent in MVPA (1.29 [0.02 to 2.56]). Subgroup analyses demonstrated that interventions only reduced BMI in studies of children (-0.09 [-0.18 to -0.00]) and in those with no active component (-0.09 [-0.18 to -0.01]). There were insufficient data to investigate the effectiveness of these interventions on HRQoL.

CONCLUSIONS

This novel systematic review and meta-analyses suggests interventions aiming to effectively reduce objectively-measured sedentary behaviour need to specifically include an active component.

Use of Time and Energy on Exercise, Prolonged TV Viewing, and Work Days

INTRODUCTION

The goal of this study was to describe differences in time use and energy expenditure associated with exercise, prolonged TV viewing, and work days in a longitudinal study of older adults.

METHODS

Participants were 1,020 adults who completed previous-day recalls that provided a profile of the use of time in sedentary and physical activity. Time use and physical activity energy expenditure were predicted for each type of day (exercise, prolonged TV, work) using linear mixed models, adjusting for age, sex, season of the year, and day of the week. Data were collected in 2012-2013; analysis was completed in 2017.

RESULTS

Exercise days had less sedentary time (-0.37 hours/day) and light activity (-0.29 hours/day), and less household, work, and shopping activities, such that the increase in total physical activity energy expenditure on exercise days (2.83 MET-hours/day) was only about half that expended during exercise (5.98 MET-hours/day). Prolonged TV viewing days had more total sedentary time (0.86 hours/days) and less light (-0.45 hours/day) and moderate-vigorous intensity activity (-0.41 hours/day), and thus lower total physical activity energy expenditure (-2.43 MET-hours/day). Work days had less sleep (-0.91 hours/day) and more total sedentary time (1.32 hours/day).

CONCLUSIONS

Exercise days had more physical activity energy expenditure, but because of reductions in other activities, only about half of the energy expended during exercise was added to total daily physical activity energy expenditure. Prolonged TV viewing days had less physical activity energy expenditure and less moderate-vigorous activity. These findings provide new insights into possible compensation associated with exercise, and suggest a strong link between TV viewing and physical inactivity.

Is the time right for quantitative public health guidelines on sitting? A narrative review of sedentary behaviour research paradigms and findings

Sedentary behaviour (SB) has been proposed as an 'independent' risk factor for chronic disease risk, attracting much research and media attention. Many countries have included generic, non-quantitative reductions in SB in their public health guidelines and calls for quantitative SB targets are increasing. The aim of this narrative review is to critically evaluate key evidence areas relating to the development of guidance on sitting for adults. We carried out a non-systematic narrative evidence synthesis across seven key areas: (1) definition of SB, (2) independence of sitting from physical activity, (3) use of television viewing as a proxy of sitting, (4) interpretation of SB evidence, (5) evidence on 'sedentary breaks', (6) evidence on objectively measured sedentary SB and mortality and (7) dose response of sitting and mortality/cardiovascular disease. Despite research progress, we still know little about the independent detrimental health effects of sitting, and the possibility that sitting is mostly the inverse of physical activity remains. Unresolved issues include an unclear definition, inconsistencies between mechanistic and epidemiological studies, over-reliance on surrogate outcomes, a very weak epidemiological evidence base to support the inclusion of 'sedentary breaks' in guidelines, reliance on self-reported sitting measures, and misinterpretation of data whereby methodologically inconsistent associations are claimed to be strong evidence. In conclusion, public health guidance requires a consistent evidence base but this is lacking for SB. The development of quantitative SB guidance, using an underdeveloped evidence base, is premature; any further recommendations for sedentary behaviour require development of the evidence base and refinement of the research paradigms used in the field.

Using open source accelerometer analysis to assess physical activity and sedentary behaviour in overweight and obese adults

Background

Physical activity and sedentary behaviour are difficult to assess in overweight and obese adults. However, the use of open-source, raw accelerometer data analysis could overcome this. This study compared raw accelerometer and questionnaire-assessed moderate-to-vigorous physical activity (MVPA), walking and sedentary behaviour in normal, overweight and obese adults, and determined the effect of using different methods to categorise overweight and obesity, namely body mass index (BMI), bioelectrical impedance analysis (BIA) and waist-to-hip ratio (WHR).

Methods

One hundred twenty adults, aged 24–60 years, wore a raw, tri-axial accelerometer (Actigraph GT3X+), for 3 days and completed a physical activity questionnaire (IPAQ-S). We used open-source accelerometer analyses to estimate MVPA, walking and sedentary behaviour from a single raw accelerometer signal. Accelerometer and questionnaire-assessed measures were compared in normal, overweight and obese adults categorised using BMI, BIA and WHR.

Results

Relationships between accelerometer and questionnaire-assessed MVPA (Rs = 0.30 to 0.48) and walking (Rs = 0.43 to 0.58) were stronger in normal and overweight groups whilst sedentary behaviour were modest (Rs = 0.22 to 0.38) in normal, overweight and obese groups. The use of WHR resulted in stronger agreement between the questionnaire and accelerometer than BMI and BIA. Finally, accelerometer data showed stronger associations with BMI, BIA and WHR (Rs = 0.40 to 0.77) than questionnaire data (Rs = 0.24 to 0.37).

Conclusions

Open-source, raw accelerometer data analysis can be used to estimate MVPA, walking and sedentary behaviour from a single acceleration signal in normal, overweight and obese adults. Our data supports the use of WHR to categorise overweight and obese adults. This evidence helps researchers obtain more accurate measures of physical activity and sedentary behaviour in overweight and obese populations.

"What Is a Step?" Differences in How a Step Is Detected among Three Popular Activity Monitors That Have Impacted Physical Activity Research

(1) Background: This study compared manually-counted treadmill walking steps from the hip-worn DigiwalkerSW200 and OmronHJ720ITC, and hip and wrist-worn ActiGraph GT3X+ and GT9X; determined brand-specific acceleration amplitude (g) and/or frequency (Hz) step-detection thresholds; and quantified key features of the acceleration signal during walking. (2) Methods: Twenty participants (Age: 26.7 ± 4.9 years) performed treadmill walking between 0.89-to-1.79 m/s (2–4 mph) while wearing a hip-worn DigiwalkerSW200, OmronHJ720ITC, GT3X+ and GT9X, and a wrist-worn GT3X+ and GT9X. A DigiwalkerSW200 and OmronHJ720ITC underwent shaker testing to determine device-specific frequency and amplitude step-detection thresholds. Simulated signal testing was used to determine thresholds for the ActiGraph step algorithm. Steps during human testing were compared using bias and confidence intervals. (3) Results: The OmronHJ720ITC was most accurate during treadmill walking. Hip and wrist-worn ActiGraph outputs were significantly different from the criterion. The DigiwalkerSW200 records steps for movements with a total acceleration of ≥1.21 g. The OmronHJ720ITC detects a step when movement has an acceleration ≥0.10 g with a dominant frequency of ≥1 Hz. The step-threshold for the ActiLife algorithm is variable based on signal frequency. Acceleration signals at the hip and wrist have distinctive patterns during treadmill walking. (4) Conclusions: Three common research-grade physical activity monitors employ different step-detection strategies, which causes variability in step output.

Does Childhood Temperamental Activity Predict Physical Activity and Sedentary Behavior over a 30-Year Period? Evidence from the Young Finns Study

PURPOSE

We examined associations between childhood temperamental activity, physical activity (PA), and television (TV) viewing over a 30-year period.

METHOD

The participants (1220 boys and 1237 girls) were aged 3, 6, 9, and 12 years in 1980 and were followed until 2011. Temperamental activity was evaluated by participants' mothers at baseline. The PA was assessed based on maternal ratings of the child from ages 3 to 6 and via self-report age from the age of 9 across all measurements. TV viewing was assessed using self-reports taken from 2001 to 2011. The associations between temperamental activity and the level and change of PA and TV viewing were determined using linear growth modeling stratified by gender and age group.

RESULTS

High temperamental activity assessed from ages 9 to 12 was associated with high levels of childhood PA in both genders, but with a steeper decline in PA levels during the first 9 years of follow-up in boys. High temperamental activity assessed from ages 3 to 6 was associated with the decline of PA from childhood to youth in girls. High childhood temperamental activity was associated with decreased levels of PA in adulthood in men, but not in women. The associations between childhood temperamental activity and TV viewing during adulthood seemed to be positive but not consistently significant in all age and gender groups.

CONCLUSION

High temperamental activity may contribute to the development of a physically inactive lifestyle. More evidence is needed with regard to gender differences among participants in similar study settings.

Quantification of walking-based physical activity and sedentary time in individuals with Rett syndrome

AIM

To quantify, in individuals with Rett syndrome with the capacity to walk, walking-based activity and sedentary time, and to analyse the influences of age, walking ability, scoliosis, and the severity of epilepsy.

METHOD

Sixty-four participants with a mean age of 17 years and 7 months (standard deviation [SD] 9y) were recruited from the Australian Rett Syndrome Database for this cross-sectional study. Each participant wore a StepWatch Activity Monitor for at least 4 days. Linear regression models were used to assess relationships between daily step count and the proportion of waking hours spent in sedentary time with the covariates of age group, walking ability, presence of scoliosis, and frequency of seizures.

RESULTS

On average, 62% (SD 19%) of waking hours were sedentary and 20% (SD 8%) was at cadences lower than or equal to 20 steps in a minute. The median daily steps count was 5093 (interquartile range 2026-8602). Compared with females younger than 13 years of age and accounting for the effects of covariates, adults took fewer steps, and both adolescents and adults had more sedentary time.

INTERPRETATION

Adolescents and adults led the least active lives and would appear to be in particular need of interventions aiming to optimize slow walking-based physical activity and reduce sedentary time.

Leisure-time physical activity, sedentary behaviors, sleep, and cardiometabolic risk factors at baseline in the PREDIMED-PLUS intervention trial: A cross-sectional analysis

Limited data exists on the interrelationships between physical activity (PA), sedentary behaviors and sleep concerning cardiometabolic risk factors in aged adults at high cardiovascular disease risk. Our aim was to examine independent and joint associations between time spent in leisure-time PA, sedentary behaviors and sleep on the prevalence of obesity, type 2 diabetes (T2D) and components of the metabolic syndrome (MetS) in Mediterranean individuals at high cardiovascular risk. Cross-sectional analyses were performed on baseline data from 5776 Spanish adults (aged 55-75y in men; 60-75y in women) with overweight/obesity and MetS, from October 2013 to October 2016, in the PREDIMED-PLUS trial. Employing multivariable-adjusted Cox regression with robust variance and constant time (given the cross-sectional design), higher prevalence of obesity, T2D and abdominal obesity as component of the MetS were associated with greater time in TV-viewing (Relative Risk, RR: 1.02, 95%CI: 1.01, 1.03; RR:1.04, 95%CI: 1.02, 1.06 and RR: 1.01 95%CI: 1.00, 1.02; respectively, all P < .01). Conversely, greater time in moderate-vigorous PA (MVPA) was associated with lower prevalence of obesity, T2D, abdominal obesity and low HDL-cholesterol (RR: 0.95, 95%CI: 0.93, 0.97; RR: 0.94, 95%CI: 0.89, 0.99; RR: 0.97, 95%CI: 0.96, 0.98; and RR: 0.95, 95%CI: 0.91, 0.99, respectively, all P < .05). For these outcomes, theoretically substituting 1-h/day of MVPA for 1-h/day TV-viewing was also significantly associated with lower prevalence (RR 0.91 to 0.97, all P < .05). Similar lower RR in these outcomes was observed when substituting 1-h/day of MVPA for 1-h/day of sleeping. Longer time watching TV and not meeting MVPA recommendations were jointly associated with higher RR of the prevalence of obesity and T2D. We concluded that, in senior individuals at high cardiovascular risk, greater time spent on MVPA and fewer on sedentary behaviors was inversely associated with prevalence of obesity, T2D, and some of the components of MetS.

Sitting behaviour is not associated with incident diabetes over 13 years: the Whitehall II cohort study

BACKGROUND

Although certain types of sedentary behaviour have been linked to metabolic risk, prospective studies describing the links between sitting with incident diabetes are scarce and often do not account for baseline adiposity. We investigate the associations between context-specific sitting and incident diabetes in a cohort of mid-aged to older British civil servants.

METHODS

Using data from the Whitehall II study (n=4811), Cox proportional hazards models (adjusted for age, sex, ethnicity, employment grade, smoking, alcohol intake, fruit and vegetable consumption, self-rated health, physical functioning, walking and moderate-to-vigorous physical activity, and body mass index (BMI)) were fitted to examine associations between total sitting and context-specific sitting time (work, television (TV), non-TV leisure time sitting at home) at phase 5 (1997-1999) and fasting glucose-defined incident diabetes up to 2011.

RESULTS

Total sitting (HR of the top compared with the bottom group: 1.26; 95% CI 1.00 to 1.62; p=0.01) and TV sitting (1.33; 95% CI 1.03 to 1.88; p=0.05) showed associations with incident diabetes; once BMI was included in the model these associations were attenuated for both total sitting (1.19; 95% CI 0.92 to 1.55; p=0.22) and TV sitting (1.31; 95% CI 0.96 to 1.76; p=0.14).

CONCLUSION

We found limited evidence linking sitting and incident diabetes over 13 years in this occupational cohort of civil servants.

Using Television-Viewing Hours and Total Hours Sitting as Interchangeable Measures of Sedentary Behavior

Sedentary behaviors, activities spent sitting, or lying down during waking hours, are of significant public health importance. Television-viewing (TV-viewing) hours and total hours sitting are common self-report measures of sedentary behaviors. Given the widespread usage of these measures, the study purpose was to measure the concordance between TV-viewing hours and total hours sitting to determine whether they can be used as interchangeable measures of time spent in sedentary behavior. Using a sample (n = 2687) of workers from a group-randomized control trial, the current study assessed the concordance between weekday total hours sitting and TV-viewing hours. Tertiles were created based on the distribution of total hours sitting and TV-viewing hours. Weighted Kappa (Kappa_w) statistics were calculated for the full sample and subgroups. Half of the sample reported 2 to 3 daily hours of TV-viewing hours and the most reported total hours sitting was 8 hours (14%). Kappa_w statistics for tertiles of total hours sitting and TV-viewing hours were 0.005 (95% CI = -0.02 to 0.03), indicating little agreement. Kappa_w statistics for subgroup analyses (body mass index categories, gender, and intervention assignment) showed poor agreement. Results do not support the use of total hours sitting and TV-viewing hours as interchangeable measures of sedentary behavior.

Objectively Measured Sedentary Time in Children and Their Parents

Background

No studies have examined associations in objectively measured sedentary time between parents and young people using activPAL posture sensors, which provide a more accurate estimate of sedentary time compared to accelerometer-based devices. This study examines patterns and associations of activPAL measured sedentary time and number of sedentary breaks on weekdays and weekend days in preschool (2–4 yrs), primary (5–11 yrs) and secondary school aged children (12–17 yrs) and their parents.

Methods

51 parents (16 M, 35 F; mean age 39 (+/−8) yrs) and 51 children (28 M, 23 F; mean age 9 (+/−5) yrs) wore an activPAL monitor for 7 days to measure time spent sedentary and number of breaks in sedentary time. Data was assessed by Pearson's correlations and t-tests.

Results

Secondary school children spent a greater percentage of their day sedentary (64.5 (+/−8.5) %) than preschool (57.4 (+/−7.3) %) and primary school children (57.2 (+/−5) %). For the secondary school parent dyad, there were no significant positive associations for time sedentary (r = −0.167, p = 0.494) and percentage of day sedentary (r = −0.247, p = 0.308). For the primary school parent dyad, there were medium, but non-significant positive correlations for time sedentary (r = 0.38, p = 0.146) and percentage of day sedentary (r = 0.363, p = 0.167). For the preschool parent dyad, there were medium—large positive correlations for percentage of waking day sedentary at weekends (r = 0.479, p = 0.083) and number of sedentary breaks (r = 0.648, p = 0.012) at weekends.

Conclusions

There were positive associations in sedentary time between primary school children and their parents, and between preschool children and their parents at the weekend. Thus, interventions aimed at reducing sedentary time of parents and children together, particularly at the weekend for young children, may be effective in these age groups. Secondary school children were more sedentary and had fewer sedentary breaks than younger children, thus interventions should promote breaks in sedentary time as well as reducing total sedentary time in this age group.

Objectively measured sedentary behavior and physical activity in a sample of Finnish adults: a cross-sectional study

Background

Regular physical activity (PA) confers many positive effects on health and well-being. Sedentary behavior (SB), in turn, is a risk factor for health, regardless of the level of moderate to vigorous PA. The present study describes the levels of objectively measured SB, breaks in SB, standing still and PA among Finnish adults.

Methods

This cross-sectional analysis is based on the sub-sample of the population-based Health 2011 Study of Finnish adults. The study population consisted of 18-to-85-year old men and women who wore a waist-worn triaxial accelerometer (Hookie AM 20) for at least 4 days, for at least 10 h per day (n = 1587) during a week. PA and SB were objectively assessed from the raw accelerometric data using novel processing and analysis algorithms with mean amplitude deviation as the processing method. The data was statistically analyzed using cross-tabulations, analysis of variance and analysis of covariance.

Results

The participants were on average 52 years old, 57 % being women. Participants were sedentary 59 % of their waking wear time, mainly sitting. They spent 17 % of the time standing still, 15 % in light intensity PA, 9 % in moderate PA and less than 1 % in vigorous PA. Participants aged 30–39 years had the highest number of breaks in SB per day. Younger participants (<30 years of age) had more moderate and vigorous PA than older ones (≥60 years of age), and 30–60-year-olds had the greatest amount of light PA.

Conclusions

Participants spent nearly 60 % of their waking time sedentary, and the majority of their daily PA was light. From a public health perspective it is important to find effective ways to decrease SB as well as to increase the level of PA. Our analysis method of raw accelerometer data may allow more precise assessment of dose-response relationships between objectively measured PA and SB and various indicators of health and well-being.