Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: a systematic review and meta-analysis

Validation study of Polar V800 accelerometer

BACKGROUND

The correct quantification of physical activity (PA) and energy expenditure (EE) in daily life is an important target for researchers and professionals. The objective of this paper is to study the validity of the Polar V800 for the quantification of PA and the estimation of EE against the ActiGraph (ActiTrainer) in healthy young adults.

METHODS

Eighteen Caucasian active people (50% women) aged between 19-23 years wore an ActiTrainer on the right hip and a Polar V800 on the preferred wrist during 7 days. Paired samples t-tests were used to analyze differences in outcomes between devices, and Pearson's correlation coefficients to examine the correlation between outcomes. The agreement was studied using the Bland-Altman method. Also, the association between the difference and the magnitude of the measurement (heteroscedasticity) was examined. Sensitivity, specificity and area under the receiver operating characteristic curve (ROC-AUC value) were calculated to evaluate the ability of the devices to accurately define a person who fulfills the recommendation of 10,000 daily steps.

RESULTS

The devices significantly differed from each other on all outcomes (P<0.05), except for Polar V800's alerts vs. ActiTrainer's 1 hour sedentary bouts (P=0.595) and Polar V800's walking time vs. ActiTrainer's lifestyle time (P=0.484). Heteroscedasticity analyses were significant for all outcomes, except for Kcal and sitting time. The ROC-AUC value was fair (0.781±0.048) and the sensitivity and specificity was 98% and 58%, respectively.

CONCLUSIONS

The Polar V800 accelerometer has a comparable validity to the accelerometer in free-living conditions, regarding "1 hour sedentary bouts" and "V800's walking time vs. ActiTrainer's lifestyle time" in young adults.

Sedentary bout durations and metabolic syndrome among working adults: a prospective cohort study

Background

This study aimed to examine the associations between time spent in prolonged and non-prolonged sedentary bouts and the development of metabolic syndrome.

Methods

We used data from a prospective study of Japanese workers. Baseline examination was conducted between 2010 and 2011. A total of 430 office workers (58 women) aged 40-64 years without metabolic syndrome were followed up by annual health checkups until 2014. Metabolic syndrome was defined as having ≥ 3 out of 5 diagnostic criteria from the Joint Interim Statement 2009 definition. Sedentary time was assessed using a tri-axial accelerometer. Time spent in total, prolonged (accumulated ≥ 30 min) and non-prolonged sedentary bouts (accumulated < 30 min) was calculated. Cox proportional hazards models were used to estimate the risk of developing metabolic syndrome.

Results

During a median follow-up of 3 years, 83 participants developed metabolic syndrome. After adjustment for age, sex, education, smoking, and family income, positive associations were observed between time spent in prolonged sedentary bouts and the development of metabolic syndrome. After additional adjustment for moderate-to-vigorous physical activity, those in the three highest quartiles of time spent in prolonged sedentary bouts showed higher risk of metabolic syndrome compared to the lowest quartile group, with adjusted hazard ratios (95 % confidence intervals) of 2.72 (1.30 – 5.73), 2.42 (1.11 – 5.50), and 2.85 (1.31 – 6.18), respectively. No associations were seen for time spent in total and non-prolonged sedentary bouts.

Conclusions

Sedentary behavior accumulated in a prolonged manner was associated with an increased risk of metabolic syndrome. In devising public health recommendations for the prevention of metabolic disease, the avoidance of prolonged uninterrupted periods of sedentary behavior should be considered.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3570-3) contains supplementary material, which is available to authorized users.

Sedentary work and the risk of breast cancer in premenopausal and postmenopausal women: a pooled analysis of two case-control studies

OBJECTIVES

There is limited research on the association between sedentary behaviour and breast cancer risk, particularly whether sedentary behaviour is differentially associated with premenopausal and postmenopausal breast cancer. We pooled data from 2 case-control studies from Australia and Canada to investigate this association.

METHODS

This pooled analysis included 1762 incident breast cancer cases and 2532 controls. Participants in both studies completed a lifetime occupational history and self-rated occupational physical activity level. A job-exposure matrix (JEM) was also applied to job titles to assess sedentary work. Logistic regression analyses (6 pooled and 12 study-specific) were conducted to estimate associations between both self-reported and JEM-assessed sedentary work and breast cancer risk among premenopausal and postmenopausal women.

RESULTS

No association was observed in the 6 pooled analyses, and 10 of the study-specific analyses also showed null results. 2 study-specific analyses provided inconsistent and contradictory results, with 1 showing statistically significant increased risk of breast cancer for self-reported sedentary work among premenopausal women cancer in the Canadian study, and the other a non-significant inverse association between JEM-assessed sedentary work and breast cancer risk among postmenopausal women in the Australian study.

CONCLUSIONS

While a suggestion of increased risk was seen for premenopausal women in the Canadian study when using the self-reported measure, overall this pooled study does not provide evidence that sedentary work is associated with breast cancer risk.

Sedentary Behavior and Cardiovascular Morbidity and Mortality: A Science Advisory From the American Heart Association

Epidemiological evidence is accumulating that indicates greater time spent in sedentary behavior is associated with all-cause and cardiovascular morbidity and mortality in adults such that some countries have disseminated broad guidelines that recommend minimizing sedentary behaviors. Research examining the possible deleterious consequences of excess sedentary behavior is rapidly evolving, with the epidemiology-based literature ahead of potential biological mechanisms that might explain the observed associations. This American Heart Association science advisory reviews the current evidence on sedentary behavior in terms of assessment methods, population prevalence, determinants, associations with cardiovascular disease incidence and mortality, potential underlying mechanisms, and interventions. Recommendations for future research on this emerging cardiovascular health topic are included. Further evidence is required to better inform public health interventions and future quantitative guidelines on sedentary behavior and cardiovascular health outcomes.

Learning to Stand: The Acceptability and Feasibility of Introducing Standing Desks into College Classrooms

Prolonged sedentary behavior is an independent risk factor for multiple negative health outcomes. Evidence supports introducing standing desks into K-12 classrooms and work settings to reduce sitting time, but no studies have been conducted in the college classroom environment. The present study explored the acceptability and feasibility of introducing standing desks in college classrooms. A total of 993 students and 149 instructors completed a single online needs assessment survey. This cross-sectional study was conducted during the fall semester of 2015 at a large Midwestern University. The large majority of students (95%) reported they would prefer the option to stand in class. Most students (82.7%) reported they currently sit during their entire class time. Most students (76.6%) and instructors (86.6%) reported being in favor of introducing standing desks into college classrooms. More than half of students and instructors predicted having access to standing desks in class would improve student’s “physical health”, “attention”, and “restlessness”. Collectively, these findings support the acceptability of introducing standing desks in college classrooms. Future research is needed to test the feasibility, cost-effectiveness and efficacy of introducing standing desks in college classrooms. Such studies would be useful for informing institutional policies regarding classroom designs.

Assessment of sedentary behaviors and transport-related activities by questionnaire: a validation study

Background

Comprehensive assessment of sedentary behavior (SB) and physical activity (PA), including transport-related activities (TRA), is required to design innovative PA promotion strategies. There are few validated instruments that simultaneously assess the different components of human movement according to their context of practice (e.g. work, transport, leisure). We examined test-retest reliability and validity of the Sedentary, Transportation and Activity Questionnaire (STAQ), a newly developed questionnaire dedicated to assessing context-specific SB, TRA and PA.

Methods

Ninety six subjects (51 women) kept a contextualized activity-logbook and wore a hip accelerometer (Actigraph GT3X + ^TM) for a 7-day or 14-day period, at the end of which they completed the STAQ. Activity-energy expenditure was measured in a subgroup of 45 subjects using the double labeled water (DLW) method. Test-retest reliability was assessed using intra-class-coefficients (ICC) in a subgroup of 32 subjects who filled the questionnaire twice one month apart. Accelerometry was annotated using the logbook to obtain total and context-specific objective estimates of SB. Spearman correlations, Bland-Altman plots and ICC were used to analyze validity with logbook, accelerometry and DLW data validity criteria.

Results

Test-retest reliability was fair for total sitting time (ICC = 0.52), good to excellent for work sitting time (ICC = 0.71), transport-related walking (ICC = 0.61) and car use (ICC = 0.67), and leisure screen-related SB (ICC = 0.64-0.79), but poor for total sitting time during leisure and transport-related contexts. For validity, compared to accelerometry, significant correlations were found for STAQ estimates of total (r = 0.54) and context-specific sitting times with stronger correlations for work sitting time (r = 0.88), and screen times (TV/DVD viewing: r = 0.46; other screens: r = 0.42) than for transport (r = 0.35) or leisure-related sitting-times (r = 0.19). Compared to contextualized logbook, STAQ estimates of TRA was higher for car (r = 0.65) than for active transport (r = 0.41). The questionnaire generally overestimated work- and leisure-related SB and sitting times, while it underestimated total and transport-related sitting times.

Conclusions

The STAQ showed acceptable reliability and a good ranking validity for assessment of context-specific SB and TRA. This instrument appears as a useful tool to study SB, TRA and PA in context in adults.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3412-3) contains supplementary material, which is available to authorized users.

Occupational physical activity in relation to risk of cardiovascular mortality: The Japan Collaborative Cohort Study for Evaluation for Cancer Risk (JACC Study)

We examined the association between patterns of occupational physical activity (OPA) and mortality from cardiovascular disease (CVD) in a Japanese population. A community-based, prospective cohort of 66,161 men and women aged 40-79years without a history of CVD or cancer at baseline (1988-1990) was followed until 2009. OPA was divided into four types: mostly sitting, sitting and standing (sitting/standing), mostly standing, and standing and walking (standing/walking). During follow-up for a median of 19.2years, 3728 deaths from CVD were registered. Compared with mostly sitting OPA, standing/walking OPA was not associated with a reduced risk of CVD mortality for all subjects, but it was associated with a 20% lower risk of CVD mortality among overweight individuals (body mass index ≥25kg/m(2)). Compared with mostly sitting OPA, mostly standing OPA was associated with an approximately 20% higher risk of CVD mortality, especially among overweight individuals or those with lower exercise (<2.5h/week). In conclusion, compared with mostly sitting OPA, standing/walking OPA is associated with lower CVD mortality among overweight individuals, while mostly standing OPA is associated with higher CVD mortality, especially in physically inactive individuals.

The Five-Factor Model of Personality and Physical Inactivity: A Meta-Analysis of 16 Samples

A sedentary lifestyle is harmful for health; personality traits may contribute to physical (in)activity. With participant-level data from 16 samples (N>125,000), we examined the personality correlates of physical inactivity, frequency of physical activity, and sedentary behavior (in a subset of samples). Lower Neuroticism and higher Conscientiousness were associated with more physical activity and less inactivity and sedentary behavior. Extraversion and Openness were also associated with more physical activity and less inactivity, but these traits were mostly unrelated to specific sedentary behaviors (e.g., TV watching). The results generally did not vary by age or sex. The findings support the notion that the interest, motivational, emotional, and interpersonal processes assessed by five-factor model traits partly shape the individual's engagement in physical activity.

The use of cardiac rehabilitation services to aid the recovery of patients with bowel cancer: a pilot randomised controlled trial with embedded feasibility study

Background

Colorectal cancer (CRC) survivors are not meeting the recommended physical activity levels associated with improving their chances of survival and quality of life. Rehabilitation could address this problem.

Objectives

The aims of the Cardiac Rehabilitation In Bowel cancer study were to assess whether or not cardiac rehabilitation is a feasible and acceptable model to aid the recovery of people with CRC and to test the feasibility and acceptability of the protocol design.

Design

Intervention testing and feasibility work (phase 1) and a pilot randomised controlled trial with embedded qualitative study (phase 2), supplemented with an economic evaluation. Randomisation was to cardiac rehabilitation or usual care. Outcomes were differences in objective measures of physical activity and sedentary behaviour, self-reported measures of quality of life, anxiety, depression and fatigue. Qualitative work involved patients and clinicians from both cancer and cardiac specialties.

Setting

Three colorectal cancer wards and three cardiac rehabilitation facilities.

Participants

Inclusion criteria were those who were aged > 18 years, had primary CRC and were post surgery.

Results

Phase 1 (single site) – of 34 patient admissions, 24 (70%) were eligible and 4 (17%) participated in cardiac rehabilitation. Sixteen clinicians participated in an interview/focus group. Modifications to trial procedures were made for further testing in phase 2. Additionally, 20 clinicians in all three sites were trained in cancer and exercise, rating it as excellent. Phase 2 (three sites) – screening, eligibility, consent and retention rates were 156 (79%), 133 (67%), 41 (31%) and 38 (93%), respectively. Questionnaire completion rates were 40 (97.5%), 31 (75%) and 25 (61%) at baseline, follow-up 1 and follow-up 2, respectively. Forty (69%) accelerometer data sets were analysed; 20 (31%) were removed owing to invalid data.

Qualitative study

CRC and cardiac patients and clinicians were interviewed. Key themes were benefits and barriers for people with CRC attending cardiac rehabilitation; generic versus disease-specific rehabilitation; key concerns of the intervention; and barriers to participation (CRC participants only).

Economic evaluation

The average out-of-pocket expenses of attending cardiac rehabilitation were £50. The costs of cardiac rehabilitation for people with cancer are highly dependent on whether it involves accommodating additional patients in an already existing service or setting up a completely new service.

Limitations and conclusions

The main limitation is that this is a small feasibility and pilot study. The main novel finding is that cardiac rehabilitation for cancer and cardiac patients together is feasible and acceptable, thereby challenging disease-specific rehabilitation models.

Future work

This study highlighted important challenges to doing a full-scale trial of cardiac rehabilitation but does not, we believe, provide sufficient evidence to reject the possibility of such a future trial. We recommend that any future trial must specifically address the challenges identified in this study, such as suboptimal consent, completion, missing data and intervention adherence rates and recruitment bias, and that an internal pilot trial be conducted. This should have clear ‘stop–proceed’ rules that are formally reviewed before proceeding to the full-scale trial.

Trial registration

Current Controlled Trials ISRCTN63510637.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full inHealth Services and Delivery Research; Vol. 4, No. 24. See the NIHR Journals Library website for further project information.

Too much sitting and all-cause mortality: is there a causal link?

Background

Sedentary behaviours (time spent sitting, with low energy expenditure) are associated with deleterious health outcomes, including all-cause mortality. Whether this association can be considered causal has yet to be established.

Using systematic reviews and primary studies from those reviews, we drew upon Bradford Hill’s criteria to consider the likelihood that sedentary behaviour in epidemiological studies is likely to be causally related to all-cause (premature) mortality.

Methods

Searches for systematic reviews on sedentary behaviours and all-cause mortality yielded 386 records which, when judged against eligibility criteria, left eight reviews (addressing 17 primary studies) for analysis. Exposure measures included self-reported total sitting time, TV viewing time, and screen time. Studies included comparisons of a low-sedentary reference group with several higher sedentary categories, or compared the highest versus lowest sedentary behaviour groups. We employed four Bradford Hill criteria: strength of association, consistency, temporality, and dose–response. Evidence supporting causality at the level of each systematic review and primary study was judged using a traffic light system depicting green for causal evidence, amber for mixed or inconclusive evidence, and red for no evidence for causality (either evidence of no effect or no evidence reported).

Results

The eight systematic reviews showed evidence for consistency (7 green) and temporality (6 green), and some evidence for strength of association (4 green). There was no evidence for a dose–response relationship (5 red). Five reviews were rated green overall. Twelve (67 %) of the primary studies were rated green, with evidence for strength and temporality.

Conclusions

There is reasonable evidence for a likely causal relationship between sedentary behaviour and all-cause mortality based on the epidemiological criteria of strength of association, consistency of effect, and temporality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3307-3) contains supplementary material, which is available to authorized users.

The SOS-framework (Systems of Sedentary behaviours): an international transdisciplinary consensus framework for the study of determinants, research priorities and policy on sedentary behaviour across the life course: a DEDIPAC-study

BACKGROUND

Ecological models are currently the most used approaches to classify and conceptualise determinants of sedentary behaviour, but these approaches are limited in their ability to capture the complexity of and interplay between determinants. The aim of the project described here was to develop a transdisciplinary dynamic framework, grounded in a system-based approach, for research on determinants of sedentary behaviour across the life span and intervention and policy planning and evaluation.

METHODS

A comprehensive concept mapping approach was used to develop the Systems Of Sedentary behaviours (SOS) framework, involving four main phases: (1) preparation, (2) generation of statements, (3) structuring (sorting and ranking), and (4) analysis and interpretation. The first two phases were undertaken between December 2013 and February 2015 by the DEDIPAC KH team (DEterminants of DIet and Physical Activity Knowledge Hub). The last two phases were completed during a two-day consensus meeting in June 2015.

RESULTS

During the first phase, 550 factors regarding sedentary behaviour were listed across three age groups (i.e., youths, adults and older adults), which were reduced to a final list of 190 life course factors in phase 2 used during the consensus meeting. In total, 69 international delegates, seven invited experts and one concept mapping consultant attended the consensus meeting. The final framework obtained during that meeting consisted of six clusters of determinants: Physical Health and Wellbeing (71% consensus), Social and Cultural Context (59% consensus), Built and Natural Environment (65% consensus), Psychology and Behaviour (80% consensus), Politics and Economics (78% consensus), and Institutional and Home Settings (78% consensus). Conducting studies on Institutional Settings was ranked as the first research priority. The view that this framework captures a system-based map of determinants of sedentary behaviour was expressed by 89% of the participants.

CONCLUSION

Through an international transdisciplinary consensus process, the SOS framework was developed for the determinants of sedentary behaviour through the life course. Investigating the influence of Institutional and Home Settings was deemed to be the most important area of research to focus on at present and potentially the most modifiable. The SOS framework can be used as an important tool to prioritise future research and to develop policies to reduce sedentary time.

10-year cumulative and bidirectional associations of domain-specific physical activity and sedentary behaviour with health-related quality of life in French adults: Results from the SU.VI.MAX studies

BACKGROUND

The directionality of the associations of domain-specific physical activity (PA) and sedentary behaviour (SB) with health-related quality of life (HRQoL) in adults remain insufficiently known. This study investigated the longitudinal associations of 10-year cumulative levels of PA and SB with HRQoL and the reverse associations.

METHODS

A sample of 2093 (47.8% men) participants from a cohort of French adult (SU.VI.MAX) was included. Data were collected at 3 time points (1998, 2001 and 2007) using the Modifiable Activity Questionnaire (MAQ) for PA (leisure-time and occupational) and SB (screen-viewing, reading and total sitting time) and the DUKE Health Profile for HRQoL. The cumulative level (from 0 to 3) referred to the number of time points where a high PA level, high SB or good HRQoL was reported. Regression models examined the 10-year cumulative level of PA, SB as predictors of HRQoL and reverse associations.

RESULTS

The 10-year cumulative level of high PA, both leisure-time and occupational, predicted a higher HRQoL while the 10-year cumulative level of high screen-viewing time and high total sitting time was associated with lower HRQoL. For the reverse association, cumulative level of good HRQoL predicted more leisure-time PA, less screen-viewing time and less total sitting time but was not related to occupational PA.

CONCLUSION

Relationships between PA, SB and HRQoL are complex and should not be oversimplified in one or the other direction. Taking into account domain-specific PA and SB in health promotion programs appears of prime importance to design interventions aiming at improving HRQoL.

'The End of Sitting': An Empirical Study on Working in an Office of the Future

BACKGROUND

Inspired by recent findings that prolonged sitting has detrimental health effects, Rietveld Architecture Art Affordances (RAAAF) and visual artist Barbara Visser designed a working environment without chairs and desks. This environment, which they called The End of Sitting, is a sculpture whose surfaces afford working in several non-sitting postures (e.g. lying, standing, leaning).

OBJECTIVE

In the present study, it was tested how people use and experience The End of Sitting. Eighteen participants were to work in this environment and in a conventional office with chairs and desks, and the participants' activities, postures, and locations in each working environment were monitored. In addition, participants' experiences with working in the offices were measured with a questionnaire.

RESULTS

It was found that 83 % of participants worked in more than one non-sitting posture in The End of Sitting. All these participants also changed location in this working environment. On the other hand, in the conventional office all but one participant sat on a chair at a desk during the entire work session. On average, participants reported that The End of Sitting supported their well-being more than the conventional office. Participants also felt more energetic after working in The End of Sitting. No differences between the working environments were found in reported concentration levels and satisfaction with the created product.

CONCLUSION

The End of Sitting is a potential alternative working environment that deserves to be examined in more detail.

Examining Non-Linear Associations between Accelerometer-Measured Physical Activity, Sedentary Behavior, and All-Cause Mortality Using Segmented Cox Regression

Healthy adults are advised to perform at least 150 min of moderate-intensity physical activity weekly, but this advice is based on studies using self-reports of questionable validity. This study examined the dose-response relationship of accelerometer-measured physical activity and sedentary behaviors on all-cause mortality using segmented Cox regression to empirically determine the break-points of the dose-response relationship. Data from 7006 adult participants aged 18 or above in the National Health and Nutrition Examination Survey waves 2003-2004 and 2005-2006 were included in the analysis and linked with death certificate data using a probabilistic matching approach in the National Death Index through December 31, 2011. Physical activity and sedentary behavior were measured using ActiGraph model 7164 accelerometer over the right hip for 7 consecutive days. Each minute with accelerometer count <100; 1952-5724; and ≥5725 were classified as sedentary, moderate-intensity physical activity, and vigorous-intensity physical activity, respectively. Segmented Cox regression was used to estimate the hazard ratio (HR) of time spent in sedentary behaviors, moderate-intensity physical activity, and vigorous-intensity physical activity and all-cause mortality, adjusted for demographic characteristics, health behaviors, and health conditions. Data were analyzed in 2016. During 47,119 person-year of follow-up, 608 deaths occurred. Each additional hour per day of sedentary behaviors was associated with a HR of 1.15 (95% CI 1.01, 1.31) among participants who spend at least 10.9 h per day on sedentary behaviors, and each additional minute per day spent on moderate-intensity physical activity was associated with a HR of 0.94 (95% CI 0.91, 0.96) among participants with daily moderate-intensity physical activity ≤14.1 min. Associations of moderate physical activity and sedentary behaviors on all-cause mortality were independent of each other. To conclude, evidence from this study supported at least 15 min per day of moderate-intensity physical activity and no more than 10.9 h per day of sedentary behaviors as recommendations to reduce all-cause mortality.

Variation in population levels of sedentary time in European adults according to cross-European studies: a systematic literature review within DEDIPAC

BACKGROUND

Sedentary behaviour is increasingly recognized as a public health risk that needs to be monitored at the population level. Across Europe, there is increasing interest in assessing population levels of sedentary time. This systematic literature review aims to provide an overview of all existing cross-European studies that measure sedentary time in adults, to describe the variation in population levels across these studies and to discuss the impact of assessment methods.

METHODS

Six literature databases (PubMed, EMBASE, CINAHL, PsycINFO, SportDiscus and OpenGrey) were searched, supplemented with backward- and forward tracking and searching authors' and experts' literature databases. Articles were included if they reported on observational studies measuring any form of sedentary time in the general population in two or more European countries. Each record was reviewed, extracted and assessed by two independent researchers, and disagreements were resolved by a third researcher. The review protocol of this review is registered in the PROSPERO database under registration number CRD42014010335.

RESULTS

Of the 9,756 unique articles that were identified in the search, twelve articles were eligible for inclusion in this review, reporting on six individual studies and three Eurobarometer surveys. These studies represented 2 to 29 countries, and 321 to 65,790 participants. Eleven studies focused on total sedentary time, while one studied screen time. The majority of studies used questionnaires to assess sedentary time, while two studies used accelerometers. Total sedentary time was reported most frequently and varied from 150 (median) to 620 (mean) minutes per day across studies and countries.

CONCLUSIONS

One third of European countries were not included in any of the studies. Objective measures of European adults are currently limited, and most studies used single-item self-reported questions without assessing sedentary behaviour types or domains. Findings varied substantially between studies, meaning that population levels of sedentary time in European adults are currently unknown. In general, people living in northern Europe countries appear to report more sedentary time than southern Europeans. The findings of this review highlight the need for standardisation of the measurement methods and the added value of cross-European surveillance of sedentary behaviour.

Variation in population levels of sedentary time in European children and adolescents according to cross-European studies: a systematic literature review within DEDIPAC

BACKGROUND

A high amount of sedentary time has been proposed as a risk factor for various health outcomes in adults. While the evidence is less clear in children and adolescents, monitoring sedentary time is important to understand the prevalence rates and how this behaviour varies over time and by place. This systematic literature review aims to provide an overview of existing cross-European studies on sedentary time in children (0-12y) and adolescents (13-18y), to describe the variation in population levels of sedentary time, and to discuss the impact of assessment methods.

METHODS

Six literature databases were searched (PubMed, EMBASE, CINAHL, PsycINFO, SportDiscus and OpenGrey), followed by backward- and forward tracking and searching authors' and experts' literature databases. Included articles were observational studies reporting on levels of sedentary time in the general population of children and/or adolescents in at least two European countries. Population levels were reported separately for children and adolescents. Data were reviewed, extracted and assessed by two researchers, with disagreements being resolved by a third researcher. The review protocol is published under registration number CRD42014013379 in the PROSPERO database.

RESULTS

Forty-two eligible articles were identified, most were cross-sectional (n = 38). The number of included European countries per article ranged from 2 to 36. Levels of sedentary time were observed to be higher in East-European countries compared to the rest of Europe. There was a large variation in assessment methods and reported outcome variables. The majority of articles used a child-specific questionnaire (60%). Other methods included accelerometers, parental questionnaires or interviews and ecological momentary assessment tools. Television time was reported as outcome variable in 57% of included articles (ranging from a mean value of 1 h to 2.7 h in children and 1.3 h to 4.4 h in adolescents), total sedentary time in 24 % (ranging from a mean value of 192 min to 552 min in children and from 268 min to 506 min in adolescents).

CONCLUSION

A substantial number of published studies report on levels of sedentary time in children and adolescents across European countries, but there was a large variation in assessment methods. Questionnaires (child specific) were used most often, but they mostly measured specific screen-based activities and did not assess total sedentary time. There is a need for harmonisation and standardisation of objective and subjective methods to assess sedentary time in children and adolescents to enable comparison across countries.

Daily physical activity and type 2 diabetes: A review

Physical activity improves glycemic control and reduces the risk of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes (T2D). Moderate to vigorous physical activity is recommended to manage T2D; however, patients with T2D can be physically weak, making it difficult to engage in the recommended levels of physical activity. Daily physical activity includes various activities performed during both occupational and leisure time such as walking, gardening, and housework that type 2 diabetic patients should be able to perform without considerable physical burden. This review focuses on the association between daily physical activity and T2D. Walking was the most common form of daily physical activity, with numerous studies demonstrating its beneficial effects on reducing the risk of T2D, CVD, and mortality. Walking for at least 30 min per day was shown to reduce the risk of T2D by approximately 50%. Additionally, walking was associated with a reduction in mortality. In contrast, evidence was extremely limited regarding other daily physical activities such as gardening and housework in patients with T2D. Recent studies have suggested daily physical activity, including non-exercise activity thermogenesis, to be favorably associated with metabolic risks and mortality. However, well-designed longitudinal studies are warranted to elucidate its effects on overall health.

Physical activity prescription: a critical opportunity to address a modifiable risk factor for the prevention and management of chronic disease: a position statement by the Canadian Academy of Sport and Exercise Medicine

Non-communicable disease is a leading threat to global health. Physical inactivity is a large contributor to this problem; in fact, the WHO ranks it as the fourth leading risk factor for overall morbidity and mortality worldwide. In Canada, at least 4 of 5 adults do not meet the Canadian Physical Activity Guidelines of 150 min of moderate-to-vigorous physical activity per week. Physicians play an important role in the dissemination of physical activity (PA) recommendations to a broad segment of the population, as over 80% of Canadians visit their doctors every year and prefer to get health information directly from them. Unfortunately, most physicians do not regularly assess or prescribe PA as part of routine care, and even when discussed, few provide specific recommendations. PA prescription has the potential to be an important therapeutic agent for all ages in primary, secondary and tertiary prevention of chronic disease. Sport and exercise medicine (SEM) physicians are particularly well suited for this role and should collaborate with their primary care colleagues for optimal patient care. The purpose of this Canadian Academy and Sport and Exercise Medicine position statement is to provide an evidence-based, best practices summary to better equip SEM and primary care physicians to prescribe PA and exercise, specifically for the prevention and management of non-communicable disease. This will be achieved by addressing common questions and perceived barriers in the field.Author note This position statement has been endorsed by the following nine sport medicine societies: Australasian College of Sports and Exercise Physicians (ACSEP), American Medical Society for Sports Medicine (AMSSM), British Association of Sports and Exercise Medicine (BASEM), European College of Sport & Exercise Physicians (ECOSEP), Norsk forening for idrettsmedisin og fysisk aktivite (NIMF), South African Sports Medicine Association (SASMA), Schweizerische Gesellschaft für Sportmedizin/Swiss Society of Sports Medicine (SGSM/SSSM), Sport Doctors Australia (SDrA), Swedish Society of Exercise and Sports Medicine (SFAIM), and CASEM.

Exercise Dose in Clinical Practice

There is wide variability in the physical activity patterns of the patients in contemporary clinical cardiovascular practice. This review is designed to address the impact of exercise dose on key cardiovascular risk factors and on mortality. We begin by examining the body of literature that supports a dose-response relationship between exercise and cardiovascular disease risk factors, including plasma lipids, hypertension, diabetes mellitus, and obesity. We next explore the relationship between exercise dose and mortality by reviewing the relevant epidemiological literature underlying current physical activity guideline recommendations. We then expand this discussion to critically examine recent data pertaining to the impact of exercise dose at the lowest and highest ends of the spectrum. Finally, we provide a framework for how the key concepts of exercise dose can be integrated into clinical practice.

The association between sedentary behaviors during weekdays and weekend with change in body composition in young adults

BACKGROUND

High sedentary time has been considered an important chronic disease risk factor but there is only limited information on the association of specific sedentary behaviors on weekdays and weekend-days with body composition. The present study examines the prospective association of total sedentary time and specific sedentary behaviors during weekdays and the weekend with body composition in young adults.

METHODS

A total of 332 adults (50% male; 27.7 ± 3.7 years) were followed over a period of 1 year. Time spent sedentary, excluding sleep (SED), and in physical activity (PA) during weekdays and weekend-days was objectively assessed every 3 months with a multi-sensor device over a period of at least 8 days. In addition, participants reported sitting time, TV time and non-work related time spent at the computer separately for weekdays and the weekend. Fat mass and fat free mass were assessed via dual x-ray absorptiometry and used to calculate percent body fat (%BF). Energy intake was estimated based on TDEE and change in body composition.

RESULTS

Cross-sectional analyses showed a significant correlation between SED and body composition (0.18 ≤ r ≤ 0.34). Associations between body weight and specific sedentary behaviors were less pronounced and significant during weekdays only (r ≤ 0.16). Nevertheless, decrease in SED during weekends, rather than during weekdays, was significantly associated with subsequent decrease in %BF (β = 0.06, p <0.01). After adjusting for PA and energy intake, results for SED were no longer significant. Only the association between change in sitting time during weekends and subsequent %BF was independent from change in PA or energy intake (β%BF = 0.04, p = 0.01), while there was no significant association between TV or computer time and subsequent body composition.

CONCLUSIONS

The stronger prospective association between sedentary behavior during weekends with subsequent body composition emphasizes the importance of leisure time behavior in weight management.

Physical activity patterns and gestational diabetes outcomes - The wings project

OBJECTIVE

To compare physical activity (PA) patterns in pregnant woman with and without gestational diabetes (GDM) and to assess the effects of an exercise intervention on change in PA patterns, blood glucose levels and pregnancy outcomes in GDM women.

METHODS

For the first objective, PA patterns were studied in 795 pregnant women with and without GDM. For the second objective, the Women in India with Gestational Diabetes Strategy-Model of Care (WINGS-MOC) intervention were evaluated in 151 women out of 189 with GDM. PA was assessed using a validated questionnaire and a pedometer. Changes in PA patterns, glycemic parameters and neonatal outcomes were evaluated.

RESULTS

Overall, only 10% of pregnant women performed recommended levels of PA. Women with GDM were significantly more sedentary compared to those without GDM (86.2 vs. 61.2%, p<0.001). After the MOC was implemented in women with GDM, there was a significant improvement in PA and a decrease in sedentary behaviour amongst women (before MOC, moderate activity: 15.2%, sedentary: 84.8% vs. after MOC-moderate: 26.5%, sedentary: 73.5%; p<0.001), and an increase in their daily step count from 2206/day to 2476/day (p<0.001). Fasting 1 and 2-h postprandial glucose values significantly decreased (p<0.001 for all). Sedentary behaviour was associated with a fourfold higher risk (p=0.02), and recreational walking with 70% decreased risk, of adverse neonatal outcomes (p=0.04) after adjusting for potential confounders.

CONCLUSIONS

PA levels are inadequate amongst this group of pregnant women studied i.e. those with and without GDM. However, a low-cost, culturally appropriate MOC can bring about significant improvements in PA in women with GDM. These changes are associated with improved glycemic control and reduction in adverse neonatal outcomes.

Benefits for Type 2 Diabetes of Interrupting Prolonged Sitting With Brief Bouts of Light Walking or Simple Resistance Activities

OBJECTIVE

To determine whether interrupting prolonged sitting with brief bouts of light-intensity walking (LW) or simple resistance activities (SRA) improves postprandial cardiometabolic risk markers in adults with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

In a randomized crossover trial, 24 inactive overweight/obese adults with T2D (14 men 62 ± 6 years old) underwent the following 8-h conditions on three separate days (with 6-14 days washout): uninterrupted sitting (control) (SIT), sitting plus 3-min bouts of LW (3.2 km · h(-1)) every 30 min, and sitting plus 3-min bouts of SRA (half-squats, calf raises, gluteal contractions, and knee raises) every 30 min. Standardized meals were consumed during each condition. Incremental areas under the curve (iAUCs) for glucose, insulin, C-peptide, and triglycerides were compared between conditions.

RESULTS

Compared with SIT, both activity-break conditions significantly attenuated iAUCs for glucose (SIT mean 24.2 mmol · h · L(-1) [95% CI 20.4-28.0] vs. LW 14.8 [11.0-18.6] and SRA 14.7 [10.9-18.5]), insulin (SIT 3,293 pmol · h · L(-1) [2,887-3,700] vs. LW 2,104 [1,696-2,511] and SRA 2,066 [1,660-2,473]), and C-peptide (SIT 15,641 pmol · h · L(-1) [14,353-16,929] vs. LW 11,504 [10,209-12,799] and SRA 11,012 [9,723-12,301]) (all P < 0.001). The iAUC for triglycerides was significantly attenuated for SRA (P < 0.001) but not for LW (SIT 4.8 mmol · h · L(-1) [3.6-6.0] vs. LW 4.0 [2.8-5.1] and SRA 2.9 [1.7-4.1]).

CONCLUSIONS

Interrupting prolonged sitting with brief bouts of LW or SRA attenuates acute postprandial glucose, insulin, C-peptide, and triglyceride responses in adults with T2D. With poor adherence to structured exercise, this approach is potentially beneficial and practical.

A randomised control trial of the cognitive effects of working in a seated as opposed to a standing position in office workers

Sedentary behaviour is increasing and has been identified as a potential significant health risk, particularly for desk-based employees. The development of sit-stand workstations in the workplace is one approach to reduce sedentary behaviour. However, there is uncertainty about the effects of sit-stand workstations on cognitive functioning. A sample of 36 university staff participated in a within-subjects randomised control trial examining the effect of sitting vs. standing for one hour per day for five consecutive days on attention, information processing speed, short-term memory, working memory and task efficiency. The results of the study showed no statistically significant difference in cognitive performance or work efficiency between the sitting and standing conditions, with all effect sizes being small to very small (all ds < .2). This result suggests that the use of sit-stand workstations is not associated with a reduction in cognitive performance. Practitioner Summary: Although it has been reported that the use of sit-stand desks may help offset adverse health effects of prolonged sitting, there is scant evidence about changes in productivity. This randomised control study showed that there was no difference between sitting and standing for one hour on cognitive function or task efficiency in university staff.

The BeUpstanding Program™: Scaling up the Stand Up Australia Workplace Intervention for Translation into Practice

Context and purpose

Too much sitting is now recognised as a common risk factor for several health outcomes, with the workplace identified as a key setting in which to address prolonged sitting time. The Stand Up Australia intervention was designed to reduce prolonged sitting in the workplace by addressing influences at multiple-levels, including the organisation, the environment, and the individual. Intervention success has been achieved within the context of randomised controlled trials, where research staff deliver several of the key intervention components. This study describes the initial step in the multi-phase process of scaling up the Stand Up Australia intervention for workplace translation.

Methods

A research-government partnership was critical in funding and informing the prototype for the scaled up BeUpstanding program™. Evidence, protocols and materials from Stand Up Australia were adapted in collaboration with funding partner Workplace Health and Safety Queensland to ensure consistency and compatibility with existing government frameworks and resources. In recognition of the key role of workplace champions in facilitating workplace health promotion programs, the BeUpstanding program™ is designed to be delivered through a stand-alone, free, website-based toolkit using a ‘train the champion’ approach.

Key findings and significance

The BeUpstanding program™ was influenced by the increasing recognition of prolonged sitting as an emerging health issue as well as industry demand. The research-government partnership was critical in informing and resourcing the development of the scaled-up program.

Reliability and Validity of the Early Years Physical Activity Questionnaire (EY-PAQ)

Measuring physical activity (PA) and sedentary time (ST) in young children (<5 years) is complex. Objective measures have high validity but require specialist expertise, are expensive, and can be burdensome for participants. A proxy-report instrument for young children that accurately measures PA and ST is needed. The aim of this study was to assess the reliability and validity of the Early Years Physical Activity Questionnaire (EY-PAQ). In a setting where English and Urdu are the predominant languages spoken by parents of young children, a sample of 196 parents and their young children (mean age 3.2 ± 0.8 years) from Bradford, UK took part in the study. A total of 156 (79.6%) questionnaires were completed in English and 40 (20.4%) were completed in transliterated Urdu. A total of 109 parents took part in the reliability aspect of the study, which involved completion of the EY-PAQ on two occasions (7.2 days apart; standard deviation (SD) = 1.1). All 196 participants took part in the validity aspect which involved comparison of EY-PAQ scores against accelerometry. Validty anaylsis used all data and data falling with specific MVPA and ST boundaries. Reliability was assessed using intra-class correlations (ICC) and validity by Bland–Altman plots and rank correlation coefficients. The test re-test reliability of the EY-PAQ was moderate for ST (ICC = 0.47) and fair for moderate-to-vigorous physical activity (MVPA)(ICC = 0.35). The EY-PAQ had poor agreement with accelerometer-determined ST (mean difference = −87.5 min·day⁻¹) and good agreement for MVPA (mean difference = 7.1 min·day⁻¹) limits of agreement were wide for all variables. The rank correlation coefficient was non-significant for ST (rho = 0.19) and significant for MVPA (rho = 0.30). The EY-PAQ has comparable validity and reliability to other PA self-report tools and is a promising population-based measure of young children’s habitual MVPA but not ST. In situations when objective methods are not possible for measurement of young children’s MVPA, the EY-PAQ may be a suitable alternative but only if boundaries are applied.

Organizational-Level Strategies With or Without an Activity Tracker to Reduce Office Workers' Sitting Time: Rationale and Study Design of a Pilot Cluster-Randomized Trial

Background

The office workplace is a key setting in which to address excessive sitting time and inadequate physical activity. One major influence on workplace sitting is the organizational environment. However, the impact of organizational-level strategies on individual level activity change is unknown. Further, the emergence of sophisticated, consumer-targeted wearable activity trackers that facilitate real-time self-monitoring of activity, may be a useful adjunct to support organizational-level strategies, but to date have received little evaluation in this workplace setting.

Objective

The aim of this study is to evaluate the feasibility, acceptability, and effectiveness of organizational-level strategies with or without an activity tracker on sitting, standing, and stepping in office workers in the short (3 months, primary aim) and long-term (12 months, secondary aim).

Methods

This study is a pilot, cluster-randomized trial (with work teams as the unit of clustering) of two interventions in office workers: organizational-level support strategies (eg, visible management support, emails) or organizational-level strategies plus the use of a waist-worn activity tracker (the LUMOback) that enables self-monitoring of sitting, standing, and stepping time and enables users to set sitting and posture alerts. The key intervention message is to ‘Stand Up, Sit Less, and Move More.’ Intervention elements will be implemented from within the organization by the Head of Workplace Wellbeing. Participants will be recruited via email and enrolled face-to-face. Assessments will occur at baseline, 3, and 12 months. Time spent sitting, sitting in prolonged (≥30 minute) bouts, standing, and stepping during work hours and across the day will be measured with activPAL3 activity monitors (7 days, 24 hours/day protocol), with total sitting time and sitting time during work hours the primary outcomes. Web-based questionnaires, LUMOback recorded data, telephone interviews, and focus groups will measure the feasibility and acceptability of both interventions and potential predictors of behavior change.

Results

Baseline and follow-up data collection has finished. Results are expected in 2016.

Conclusions

This pilot, cluster-randomized trial will evaluate the feasibility, acceptability, and effectiveness of two interventions targeting reductions in sitting and increases in standing and stepping in office workers. Few studies have evaluated these intervention strategies and this study has the potential to contribute both short and long-term findings.

Beyond Calories: An Integrated Approach to Promote Health, Longevity, and Well-Being

In 1948, the World Health Organization defined health as 'a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity'. Detractors claim that this definition of health is utopian and unrealistic. However, accumulating evidence from experimental studies suggests that aging is not inevitably linked with the development of chronic diseases, and the age-associated accumulation of molecular damage can be prevented or greatly delayed by dietary and genetic manipulations that downregulate key cellular nutrient-sensing pathways. Nonetheless, to obtain a state of complete physical, mental, and social well-being, we as human beings need to go beyond nutrition or pharmacological treatments and implement a combination of interventions that enhance not only our metabolic health but also our psychological, emotional, intellectual and spiritual development, our social relationships and cultural well-being. This perspective highlights a range of scientific research-based interventions that can potentially be used to promote human health and longevity. We will also briefly address the importance of environmental health in achieving this goal.

Correlates of objectively measured sedentary behavior in breast cancer survivors

BACKGROUND

Emerging evidence indicates increased sedentary behavior is associated with poorer health outcomes and quality of life among cancer survivors. However, very little is known about which factors are associated with increased sedentary behavior. The purpose of the present study was to examine potential correlates of sedentary behavior among breast cancer survivors.

METHODS

We used hierarchical general linear modeling to examine the associations between demographic, disease-specific, and psychosocial factors at baseline and accelerometer-estimated daily proportion of time spent sedentary at 6 months in breast cancer survivors [n = 342; M age = 56.7 (SD = 9.4)]. All models adjusted for objectively measured moderate and vigorous intensity physical activity and sedentary behavior at baseline.

RESULTS

The final model including all baseline potential predictor variables and physical activity and sedentary behavior explained 49.8 % of the variance in the proportion of daily time spent sedentary at 6 months. The following factors were significantly (p < 0.05) associated with increased sedentary behavior among breast cancer survivors: higher number of comorbidities, more advanced disease stage, and increased fatigue severity. Additionally, being treated with surgery and chemotherapy was significantly related to a lower proportion of time spent sedentary compared to women who had received surgery alone.

CONCLUSIONS

This study provides preliminary insight into factors associated with sedentary behavior in breast cancer survivors. Future research is warranted to understand the potential demographic, disease-specific, psychosocial correlates of sedentary behavior to determine which correlates are potential mechanisms of behavior change and intervention targets.

Worksite Physical Activity Intervention for Ambulatory Clinic Nursing Staff

Health behaviors, including physical activity (PA), of registered nurses (RNs) and medical assistants (MAs) are suboptimal but may improve with worksite programs. Using a repeated-measures crossover design, the authors explored if integrating a 6-month worksite non-exercise activity thermogenesis (NEAT) intervention, with and without personalized health coaching via text messaging into workflow could positively affect sedentary time, PA, and body composition of nursing staff without jeopardizing work productivity. Two ambulatory clinics were randomly assigned to an environmental NEAT intervention plus a mobile text message coaching for either the first 3 months (early texting group, n = 27) or the last 3 months (delayed texting group, n = 13), with baseline 3-month and 6-month measurements. Sedentary and PA levels, fat mass, and weight improved for both groups, significantly only for the early text group. Productivity did not decline for either group. This worksite intervention is feasible and may benefit nursing staff.

Top 10 research questions to promote physical activity in bipolar disorders: A consensus statement from the International Organization of Physical Therapists in Mental Health

BACKGROUND

Research has only recently started to consider the importance and applicability of physical activity (PA) for people with bipolar disorder (BD). The aim of the current study is to highlight 10 pertinent PA research questions in people with BD.

METHODS

The International Organization of Physical Therapy in Mental Health executed a consultation with all National organizations (n=13) to identify the most salient questions to guide future research on PA in BD.

RESULTS

We identified the following 10 questions: (1) What are the benefits of PA for people with BD? (2) What are the most prominent safety issues for PA prescription in BD? (3) What is the optimal PA prescription for people with BD? (4) What are the key barriers to PA among people with BD? (5) What are the most effective motivational strategies for ensuring PA adoption and maintenance in BD? (6) How do we translate PA research into community practice? (7) If one treatment goal is increased physical activity, what type of professionals are needed as part of a multidisciplinary team? (8) How do we incorporate PA as a vital sign in clinical practice? (9) How can we prevent sedentary behavior in BD? (10) What is the most appropriate PA assessment method?

LIMITATIONS

We did not consult people with BD.

CONCLUSIONS

Addressing these questions is critical for developing evidence-based approaches for promoting and sustaining an active lifestyle in BD. Ultimately, achieving this will reduce the burden of cardiovascular disease and improve the quality of life of this population.

Decreased Vigorous Physical Activity in School-Aged Children with Human Immunodeficiency Virus in Johannesburg, South Africa

OBJECTIVE

To describe physical activity in South African children with and without HIV.

STUDY DESIGN

Study measurements were obtained in 218 children with perinatal HIV and 180 children without HIV aged 5-9 years in a study conducted in Johannesburg, South Africa. Weight-for-age z-score, height-for-age z-score, frequency and duration of moderate and vigorous physical activity, and sedentary behaviors were obtained. These measurements were compared between children with and without HIV.

RESULTS

Weight-for-age z-score and height-for-age z-score were significantly lower for children with HIV compared with those without HIV. Among children who attended school, fewer children with HIV than children without HIV participated in physical education (41% vs 64%; P = .0003) and organized after-school sports (38% vs 64%; P < .001). The proportion of children in both groups meeting World Health Organization recommendations for physical activity was similar (84% overall); however, girls with HIV spent less time in vigorous physical activity than girls without HIV (420 vs 780 minutes/week; P = .001). This difference remained significant even when girls with a medical condition with the potential to limit physical activity were excluded, and after adjusting for age. Time spent in sedentary behaviors did not differ significantly between the two groups.

CONCLUSION

Although children with HIV with well-controlled disease after initiating antiretroviral therapy early in life achieve high levels of physical activity, vigorous physical activity is lower in girls with HIV than in healthy controls. This finding may reflect lower participation in school-based physical education and organized after-school physical activity.

A systematic review and meta-analysis of workplace intervention strategies to reduce sedentary time in white-collar workers

Prolonged sedentary behaviour has been associated with various detrimental health risks. Workplace sitting is particularly important, providing it occupies majority of total daily sedentary behaviour among desk-based employees. The aim of this systematic review and meta-analysis was to examine the effectiveness of workplace interventions overall, and according to different intervention strategies (educational/behavioural, environmental and multi-component interventions) for reducing sitting among white-collar working adults. Articles published through December 2015 were identified in five online databases and manual searches. Twenty-six controlled intervention studies published between 2003 and 2015 of 4568 working adults were included. All 26 studies were presented qualitatively, and 21 studies with a control group without any intervention were included in the meta-analysis. The pooled intervention effect showed a significant workplace sitting reduction of -39.6 min/8-h workday (95% confidence interval [CI]: -51.7, -27.5), favouring the intervention group. Multi-component interventions reported the greatest workplace sitting reduction (-88.8 min/8-h workday; 95% CI: -132.7, -44.9), followed by environmental (-72.8 min/8-h workday; 95% CI: -104.9, -40.6) and educational/behavioural strategies -15.5 min/8-h workday (95% CI:-22.9,-8.2). Our study found consistent evidence for intervention effectiveness in reducing workplace sitting, particularly for multi-component and environmental strategies. Methodologically rigorous studies using standardized and objectively determined outcomes are warranted. © 2016 World Obesity.

Change in Physical Activity and Sedentary Time Associated With 2-Year Weight Loss in Obese Adults With Osteoarthritis

BACKGROUND

We examined if changes in moderate-to-vigorous physical activity (MVPA), light activity, and sedentary behavior are related to weight change over a 2-year period in obese adults with/elevated risk for knee osteoarthritis.

METHODS

Weight, physical activity, and sedentary time at baseline and 2 years were obtained from 459 obese participants from the Osteoarthritis Initiative. Weight change was categorized as ≥ 10 lbs, 5.0 to 9.9 lbs, 4.9 to -4.9 lbs, -5.0 to -9.9 lbs, and ≤ -10 lbs. We examined the association between 2-year weight change categories and changes in activity/sedentary time from accelerometer monitoring by multiple linear regression adjusted for baseline weight, demographic, and health factors.

RESULTS

Across the 5 weight categories (loss to gain), average 2-year change ranged from -7.4 to 28.0 sedentary minutes/ day, 4.2 to -23.1 light activity minutes/day, and 3.2 to -4.9 MVPA minutes/day, respectively. Higher weight loss categories were separately associated with increased MVPA (P for trend < 0.001) and less sedentary gain (P for trend = 0.01). Weight loss categories had a strong trend with light activity gain but not statistically significant (P for trend = 0.06).

CONCLUSIONS

Small increases in MVPA and decreases in sedentary time over 2 years were associated with weight loss among adults with obesity and with or at elevated risk for knee osteoarthritis.

Assessing and understanding sedentary behaviour in office-based working adults: a mixed-method approach

Background

Sedentary behaviours (SB) can be characterized by low energy expenditure in a reclining position (e.g., sitting) often associated with work and transport. Prolonged SB is associated with increased risk for chronic conditions, and due to technological advances, the working population is in office settings with high occupational exposure to SB. This study aims to assess SB among office workers, as well as barriers and strategies towards reducing SB in the work setting.

Methods

Using a mixed-methods approach guided by the socio-ecological framework, non-academic office workers from a professional school in a large public university were recruited. Of 180 eligible office workers, 40 enrolled and completed all assessments. Self-reported and objectively measured SB and activity levels were captured. Focus group discussion (FGD) were conducted to further understand perceptions, barriers, and strategies to reducing workplace SB. Environmental factors were systematically evaluated by trained research staff using an adapted version of the Checklist for Health Promotion Environments at Worksites (CHEW). Thematic analysis of FGD was conducted and descriptive analysis of quantitative data was performed.

Results

The sample was mostly Chinese (n = 33, 80 %) with a total of 24 (60 %) female participants. Most participants worked five days a week for about 9.5(0.5) hrs/day. Accelerometer data show that participants spend the majority of their days in sedentary activities both on workdays (76.9 %) and non-workdays (69.5 %). Self-report data confirm these findings with median sitting time of 420(180) minutes at work. From qualitative analyses, major barriers to reducing SB emerged, including the following themes: workplace social and cultural norms, personal factors, job scope, and physical building/office infrastructure. CHEW results confirm a lack of support from the physical infrastructure and information environment to reducing SB.

Conclusions

There is high SB among office workers in this sample. We identified multiple levels of influence for prolonged occupational SB, with a particular emphasis on workplace norms and infrastructure as important barriers to reducing SB and increasing PA. A larger, representative sample of the Singaporean population is needed to confirm our findings but it seems that any intervention aimed at reducing SB in the workplace should target individual, environmental, and organizational levels.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3023-z) contains supplementary material, which is available to authorized users.

Osteoarthritis and mortality: A prospective cohort study and systematic review with meta-analysis

OBJECTIVES

Osteoarthritis (OA) is a leading cause of disability, but the relationship with premature mortality remains uncertain. We aimed to investigate the relationship between OA and mortality from any cause and from cardiovascular disease (CVD).

METHODS

Electronic literature databases searches were conducted to identify prospective studies comparing mortality in a sample of people with and without OA. Risk of all-cause and CVD mortality were summarized using adjusted hazard ratios (HRs) for joint specific (hand, hip, and knee) and joint non-specific OA. New data from the Progetto Veneto Anziani (PRO.V.A.) study were also included.

RESULTS

From the PRO.V.A. study (N = 2927), there was no significant increase in mortality risk for participants with any joint OA (N = 1858) compared to non-OA (all-cause, HR = 0.95, 95% CI: 0.77-1.15 and CVD, HR = 1.12, 95% CI: 0.82-1.54). On meta-analysis, seven studies (OA = 10,018/non-OA = 18,541), with a median 12-year follow-up, reported no increased risk of any-cause mortality in those with OA (HR = 1.10, 95% CI: 0.97-1.25). After removing data on hand OA, a significant association between OA and mortality was observed (HR = 1.18, 95% CI: 1.08-1.28). There was a significant higher risk of overall mortality for (1) studies conducted in Europe, (2) patients with multi-joint OA; and (3) a radiological diagnosis of OA. OA was associated with significantly higher CVD mortality (HR = 1.21, 95% CI: 1.10-1.34).

CONCLUSIONS

People with OA are at increased risk of death due to CVD. The relationship with overall mortality is less clear and may be moderated by the presence of hand OA.

Sedentary behaviour in people with multiple sclerosis: Is it time to stand up against MS?

Historically, people with multiple sclerosis (MS) have been considered sedentary, although the actual scientific study of sedentary behaviour in MS did not originate until 2011. Sedentary behaviour, which is conceptually distinct from physical inactivity, is defined as any waking activity characterised by an energy expenditure ⩽ 1.5 metabolic equivalents and in a sitting or reclining posture. In the general population, the volume of sitting time is associated with increased risks of morbidity and mortality, independent of physical activity, and has been suggested to carry a greater risk of mortality than smoking behaviour. There are many symptoms of MS (e.g. mobility disability and fatigue) that could increase the prevalence of sedentary behaviour, and sedentary behaviour may have considerable implications for the development of comorbid conditions prevalent in MS. This review provides a summary of the rates, correlates, consequences and interventions attempting to reduce sedentary behaviour in MS. We provide a research agenda that guides future research on sedentary behaviour in MS. This paper provides a clarion call that it is time to 'stand up against MS'.

Combating the Health Risks of Sedentary Behavior in the Contemporary Radiology Reading Room

OBJECTIVE

We detail the association of sedentary behavior with a variety of health problems and provide the radiologist with a number of simple activities and techniques that can improve overall health while still meeting the productivity demands of a high-volume practice. Although these techniques are well known and recognized in the fitness and nutrition literature, they are not widely used in the radiology reading room. The computer- and workstation-based work routinely performed by diagnostic radiologists typically occurs in the seated position, leading to more than 8 hours per day of sitting. Studies have found that even for those who exercise regularly, spending increased time sitting can negate the healthful effects of exercise. Time spent in a seated or sedentary position leads to slowing of one's metabolism, with negative resultant effects.

CONCLUSION

The concept of nonexercise activity thermogenesis (NEAT) will be described, with examples given of how to burn more calories while at work and, therefore, improve the health of the diagnostic radiologist. NEAT refers to the energy expended during activities of daily living, excluding sportlike or intentional exercise. The concept of NEAT must be understood by radiologists, because it allows the development of multiple strategies to combat the ill effects of sitting while working. Adding intermittent movement and stretching exercises throughout the day can stimulate metabolism. An understanding of the association of sedentary work behavior with a number of health risks is crucial for radiologists so that they can implement basic changes into their work routine, allowing them to increase activity to address and avoid these potential health hazards.

Effect of steroid hormones, estrogen and progesterone, on epithelial mesenchymal transition in ovarian cancer development

As the primary female sex steroid hormones, estrogens and progesterone play important roles to regulate growth, differentiation, and function of a broad range of target tissues in the human body and maintain the function of female reproductive tissues. Ovarian cancer is the most cause of cancer death in gynecological malignancy. Despite enormous outcomes in the understanding of ovarian cancer pathology, this disease has resulted in poor survival rates since most patients are asymptomatic until the disease has been metastasized. The exact molecular events leading to metastasis of ovarian tumor cells have not yet been well elucidated, although it is recognized that the acquisition of capacity for migration and invasiveness would be a necessary prerequisite. During metastasis, epithelial-mesenchymal transition (EMT) is an important process, in which epithelial cells lose their intracellular adhesion and cell polarity and acquire increased motility and invasive properties to become mesenchymal like cells. The process of cancer cells to undergo EMT is regulated through the up- and down- regulation of a multiple cellular markers and signaling proteins. In this review, we focused the roles of women sex steroid hormones, estrogen and progesterone, in ovarian cancer, especially the ovarian cancer undergoing EMT and metastatic process. All things considered, we may suggest that progesterone is a potent hormone which inhibits the growth of human ovarian cancer cells and development to metastasis whereas estrogen may act as a risk factor of ovarian cancer progression and that progesterone therapy may be an alternative clinically effective tool for the treatment of human ovarian cancer.

Reduced Physical Activity in People Following Ankle Fractures: A Longitudinal Study

STUDY DESIGN

Longitudinal observational cohort.

BACKGROUND

The impact of ankle fracture on physical activity and sitting time and the course of recovery of physical activity are unclear.

OBJECTIVES

To assess the course of recovery of physical activity after ankle fracture and the extent to which this population may be less physically active and more sedentary than the general population.

METHODS

A cohort of individuals with ankle fracture was derived from a randomized trial and assessed with the International Physical Activity Questionnaire-Short Form (IPAQ-SF) at immobilization removal and 1, 3, and 6 months later. Total metabolic equivalent (MET) minutes per week were calculated to evaluate the course of recovery of physical activity. Sitting time (minutes per day) and the percentage of those who met the World Health Organization physical activity guidelines were calculated. Normative data were derived from a population-based cohort study that assessed physical activity using the IPAQ-SF.

RESULTS

In people with ankle fracture (n = 214), physical activity increased in the first month (from a median of 99 at immobilization removal to 979 MET min/wk) and leveled off by 6 months (1386 MET min/wk). Only 22% of the ankle fracture cohort met World Health Organization guidelines at immobilization removal, compared to 80% of the cohort from the general population (P<.001). This difference diminished over time. Sitting time in the ankle fracture cohort was higher than population norms at all time points (P<.001).

CONCLUSION

People with ankle fracture are less physically active and more sedentary than the general population. Strategies to increase physical activity must be considered. LEVEL OF EVIDENCE Prognosis, level 4.

A novel approach for measuring energy expenditure of a single sit-to-stand movement

PURPOSE

The purpose of this study was to quantify the energy expenditure (EE) of a sit-to-stand (STS) movement using a recently developed method and to examine the relationship between physical characteristics and the physiological demands of STS.

METHODS

Nineteen participants completed a multi-stage test at different STS frequencies of 6, 10, 15, 20 and 30 repetitions per minute. The expired gas, heart rate (HR) and rating of perceived exertion (RPE) were measured. The relationship between EE and STS frequency was obtained and the slope of the regression was quantified as the EE of an STS.

RESULTS

The gross EE and HR increased linearly as the STS frequency increased in all participants. The net EE of an STS was 0.92 ± 0.37 kJ. The EE of an STS increased as the height and weight increased, and these relationships were well fit by quadratic regression. The metabolic equivalent (Met) of performing 15 STSs per minute was 4.3 ± 1.0 Mets and RPE was 12 ± 1 over a total of 20.

CONCLUSION

This study demonstrated that the EE of an instantaneous movement can be quantified by relating the gross EE and different frequencies of movement. Using this method, we quantified the EE of an STS, which varied depending on participants' anthropometrics. Mets of repetitive STS movement ranged from 2.6 to 7.2. This physiological profile is useful when performing repetitive STS movements as a form of exercise.

Objectively measured patterns of sedentary time and physical activity in young adults of the Raine study cohort

Background

To provide a detailed description of young adults’ sedentary time and physical activity.

Methods

384 young women and 389 young men aged 22.1 ± 0.6 years, all participants in the 22 year old follow-up of the Raine Study pregnancy cohort, wore Actigraph GT3X+ monitors on the hip for 24 h/day over a one-week period for at least one ‘valid’ day (≥10 h of waking wear time). Each minute epoch was classified as sedentary, light, moderate or vigorous intensity using 100 count and Freedson cut-points. Mixed models assessed hourly and daily variation; t-tests assessed gender differences.

Results

The average (mean ± SD) waking wear time was 15.0 ± 1.6 h/day, of which 61.4 ± 10.1 % was spent sedentary, 34.6 ± 9.1 % in light-, 3.7 ± 5.3 % in moderate- and, 0.3 ± 0.6 % in vigorous-intensity activity. Average time spent in moderate to vigorous activity (MVPA) was 36.2 ± 27.5 min/day. Relative to men, women had higher sedentary time, but also higher vigorous activity time. The ‘usual’ bout duration of sedentary time was 11.8 ± 4.5 min in women and 11.7 ± 5.2 min in men. By contrast, other activities were accumulated in shorter bout durations. There was large variation by hour of the day and by day of the week in both sedentary time and MVPA. Evenings and Sundays through Wednesdays tended to be particularly sedentary and/or inactive.

Conclusion

For these young adults, much of the waking day was spent sedentary and many participants were physically inactive (low levels of MVPA). We provide novel evidence on the time for which activities were performed and on the time periods when young adults were more sedentary and/or less active. With high sedentary time and low MVPA, young adults may be at risk for the life-course sequelae of these behaviours.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-016-0363-0) contains supplementary material, which is available to authorized users.