Occupational sitting and health risks: a systematic review

Standing time and all-cause mortality in a large cohort of Australian adults

OBJECTIVE

To determine the association between standing time and all-cause mortality.

METHODS

Prospective questionnaire data from 221,240 individuals from the 45 and Up Study were linked to mortality data from the New South Wales Registry of Deaths (Australia) from February 1, 2006 to June 17, 2012. Hazard ratios for all-cause mortality according to standing time at baseline were estimated in 2013 using Cox regression modelling, adjusted for sex, age, education, urban/rural residence, physical activity, sitting time, body mass index, smoking status, self-rated health and disability.

RESULTS

During 937,411 person years (mean follow-up=4.2 yr) 8009 deaths occurred. All-cause mortality hazard ratios were 0.90 (95% CI 0.85-0.95), 0.85 (95% CI 0.80-0.95), and 0.76 (95% CI 0.69-0.95) for standing 2-≤5h/d, 5-≤8h/d, or >8h/d respectively, compared to standing two or less hours per day. Further analyses revealed no significant interactions between standing and sex (p=0.93), the presence/absence of cardiovascular disease or diabetes (p=0.22), BMI (p=0.78), physical activity (p=0.16) and sitting time (p=0.22).

CONCLUSION

This study showed a dose-response association between standing time and all-cause mortality in Australian adults aged 45 years and older. Increasing standing may hold promise for alleviating the health risks of prolonged sitting.

The relationship between sedentary behaviour and physical activity in adults: a systematic review

To ascertain, through a systematic review, the associations between sedentary behaviour (SB) and physical activity (PA) among adults aged 18-60years. Studies published in English up to and including June 2013 were located from computerized and manual searches. Studies reporting on at least one measure of SB and an association with one measure of PA were included. 26 studies met the inclusion criteria. Six studies examined associations between SB and PA prospectively, and 20 were cross-sectional. The most commonly assessed subtype of sedentary behaviours were television viewing (11 studies), total sedentary time (10), total sitting time (4), general screen time (3) and occupational sedentary time (2). All studied types of SB were associated with lower levels of PA in adults. Findings of this review suggest inverse associations between SB and PA were weak to moderate. Objective monitoring studies reported larger negative associations between SB and light intensity activity. Current evidence, though limited, supports the notion that sedentary behaviour displaces light intensity activity.

Occupational sitting and weight status in a diverse sample of employees in Midwest metropolitan cities, 2012-2013

Introduction

Few studies have examined the association between occupational sitting and body mass index (BMI). There is a particular lack of evidence among diverse populations. The objective of this study was to quantify the association between self-reported occupational sitting time and BMI by sex and race, independent of levels of occupational and leisure-time physical activity.

Methods

In 2012 and 2013, participants residing in 4 Missouri metropolitan areas were interviewed via telephone. The interview included questions on sociodemographic characteristics and time spent sitting at work. Multinomial logistic regressions were used to examine the association between occupational sitting and BMI between men and women and between black and white women.

Results

Overall 1,891 participants (66.9% women, 29.5% black) provided complete data. Median daily time spent by both men and women in occupational sitting was 180 minutes (interquartile range, 30 to 360 minutes); most participants were overweight (32.3%) or obese (33.6%). After adjusting for potential confounders, we found that black women in 3 categories of sitting time (31–180 minutes, 181–360 minutes, and >360 minutes) were approximately 2.5 times as likely (P for trend, .02) to be obese as black women who reported sitting for 30 minutes or less, independent of occupational and leisure-time physical activity. This association was not seen among white women. No significant associations were found among men.

Conclusion

Occupational sitting is associated with an increased likelihood of obesity among black women, independent of occupational and leisure-time physical activity. Areas of future research include evaluating associations among various occupations and industries, assessing the association in prospective cohorts, and exploring the feasibility of worksite interventions that target sitting.

An early-stage epidemic: a systematic review of correlates of smoking among Chinese women

BACKGROUND

Despite the historically low smoking prevalence among Chinese women, there is a trend of future increase.

PURPOSE

We systematically reviewed the correlates of smoking among Chinese girls and women.

METHOD

We conducted a systematic review of literature on correlates of smoking among Chinese women using Medline and China Academic Journals databases. Following the PRISMA statement, two investigators independently searched for literature, identified and reviewed papers, assessed the quality of the papers, and extracted information. The characteristics of studies and correlates of smoking were synthesized separately for youth and adults.

RESULTS

A total of 15 articles (11 on adults, 4 on youth) met the inclusion criteria. Based on these studies, peer smoking was the most consistent correlate of smoking among Chinese girls. Among Chinese women, partner smoking, job-related stress, and exposure to cigarettes made for women were consistent correlates of smoking. Knowledge of harms and negative attitudes towards smoking were found to be negatively associated with smoking.

CONCLUSION

Overall, the evidence base for smoking among Chinese women is limited. Although smoking among Chinese women is still at an early stage, it is becoming more prevalent among specific population subgroups, such as rural-to-urban migrant workers. Although further research is needed, findings from the current study provide a roadmap for research and policy on prevention of smoking among Chinese girls and women.

Effects of a standing and three dynamic workstations on computer task performance and cognitive function tests

Sedentary work entails health risks. Dynamic (or active) workstations, at which computer tasks can be combined with physical activity, may reduce the risks of sedentary behaviour. The aim of this study was to evaluate short term task performance while working on three dynamic workstations: a treadmill, an elliptical trainer, a bicycle ergometer and a conventional standing workstation. A standard sitting workstation served as control condition. Fifteen Dutch adults performed five standardised but common office tasks in an office-like laboratory setting. Both objective and perceived work performance were measured. With the exception of high precision mouse tasks, short term work performance was not affected by working on a dynamic or a standing workstation. The participant's perception of decreased performance might complicate the acceptance of dynamic workstations, although most participants indicate that they would use a dynamic workstation if available at the workplace.

The effectiveness of sit-stand workstations for changing office workers' sitting time: results from the Stand@Work randomized controlled trial pilot

Background

Prolonged sitting time is detrimental for health. Individuals with desk-based occupations tend to sit a great deal and sit-stand workstations have been identified as a potential strategy to reduce sitting time. Hence, the objective of the current study was to examine the effects of using sit-stand workstations on office workers’ sitting time at work and over the whole day.

Methods

We conducted a randomized controlled trial pilot with crossover design and waiting list control in Sydney, Australia from September 2011 to July 2012 (n = 42; 86% female; mean age 38 ± 11 years). Participants used a sit-stand workstation for four weeks in the intervention condition. In the time-matched control condition, participants received nothing and crossed over to the intervention condition after four weeks. The primary outcomes, sitting, standing and walking time at work, were assessed before and after using the workstations with ActivPALs and self-report questionnaires. Secondary outcomes, domain-specific sitting over the whole day, were assessed by self-report. Linear mixed models estimated changes in outcomes adjusting for measurement time, study grouping and covariates.

Results

Intervention participants significantly reduced objectively assessed time spent sitting at work by 73 min/workday (95% CI: −106,-39) and increased standing time at work by 65 min/workday (95% CI: 47, 83); these changes were significant relative to controls (p = 0.004 and p < 0.001, respectively). Total sitting time significantly declined in intervention participants (−80 min/workday; 95% CI: −155, −4).

Conclusions

This study shows that introducing sit-stand workstations in the office can reduce desk-based workers’ sitting time at work in the short term. Larger scale studies on more representative samples are needed to determine the public health impact of sit-stand workstations.

Trial registration

ACTRN12612000072819

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-014-0127-7) contains supplementary material, which is available to authorized users.

Body mass index: accounting for full time sedentary occupation and 24-hr self-reported time use

Objectives

We used linked existing data from the 2006–2008 American Time Use Survey (ATUS), the Current Population Survey (CPS, a federal survey that provides on-going U.S. vital statistics, including employment rates) and self-reported body mass index (BMI) to answer: How does BMI vary across full time occupations dichotomized as sedentary/non-sedentary, accounting for time spent in sleep, other sedentary behaviors, and light, moderate, and vigorous intensity activities?

Methods

We classified time spent engaged at a primary job (sedentary or non-sedentary), sleep, and other non-work, non-sleep intensity-defined behaviors, specifically, sedentary behavior, light, moderate, and vigorous intensity activities. Age groups were defined by 20–29, 30–39, 40–49, and 50–64 years. BMI groups were defined by 18.5–24.9, 25.0–27.4, 27.5–29.9, 30.0–34.9, and ≥35.0 kg/m². Logistic and linear regression were used to examine the association between BMI and employment in a sedentary occupation, considering time spent in sleep, other non-work time spent in sedentary behaviors, and light, moderate, and vigorous intensity activities, sex, age race/ethnicity, and household income.

Results

The analysis data set comprised 4,092 non-pregnant, non-underweight individuals 20–64 years of age who also reported working more than 7 hours at their primary jobs on their designated time use reporting day. Logistic and linear regression analyses failed to reveal any associations between BMI and the sedentary/non-sedentary occupation dichotomy considering time spent in sleep, other non-work time spent in sedentary behaviors, and light, moderate, and vigorous intensity activities, sex, age, race/ethnicity, and household income.

Conclusions

We found no evidence of a relationship between self-reported full time sedentary occupation classification and BMI after accounting for sex, age, race/ethnicity, and household income and 24-hours of time use including non-work related physical activity and sedentary behaviors. The various sources of error associated with self-report methods and assignment of generalized activity and occupational intensity categories could compound to obscure any real relationships.

Reducing occupational sedentary time: a systematic review and meta-analysis of evidence on activity-permissive workstations

Excessive sedentary time is detrimentally linked to obesity, type 2 diabetes, cardiovascular disease and premature mortality. Studies have been investigating the use of activity-permissive workstations to reduce sedentary time in office workers, a highly sedentary target group. This review systematically summarizes the evidence for activity-permissive workstations on sedentary time, health-risk biomarkers, work performance and feasibility indicators in office workplaces. In July 2013, a literature search identified 38 relevant peer-reviewed publications. Key findings were independently extracted by two researchers. The average intervention effect on sedentary time was calculated via meta-analysis. In total, 984 participants across 19 field-based trials and 19 laboratory investigations were included, with sample sizes ranging from n = 2 to 66 per study. Sedentary time, health-risk biomarkers and work performance indicators were reported in 13, 23 and 23 studies, respectively. The pooled effect size from the meta-analysis was -77 min of sedentary time/8-h workday (95% confidence interval = -120, -35 min). Non-significant changes were reported for most health- and work-related outcomes. Studies with acceptability measures reported predominantly positive feedback. Findings suggest that activity-permissive workstations can be effective to reduce occupational sedentary time, without compromising work performance. Larger and longer-term randomized-controlled trials are needed to understand the sustainability of the sedentary time reductions and their longer-term impacts on health- and work-related outcomes.

Relationship between daily physical activity level and low back pain in young, female desk-job workers

OBJECTIVES

The purpose of this study was to investigate the relationship between daily physical activity (PA) level and low back pain (LBP) in young women.

MATERIAL AND METHODS

Two hundred forty three female, desk-job workers aged 20-40 voluntarily participated in the study. The participants were assessed by the use of Oswestry Disability Index for measuring LBP disability and by the use of the short version of the International Physical Activity Questionnaire for PA assessment. The 1-way ANOVA test was used for comparing the mean values according to the physical activity level groups. Correlations between the average LBP disability score and all the other variables were obtained using Pearson's correlation analysis. The level of statistical significance was p < 0.05.

RESULTS

Significant differences were found for LBP disability score between the results of 3 different PA groups (p < 0.05) (low, moderate and high PA groups). The correlation between the average LBP disability score and body weight (r = 0.187, p < 0.01), body mass index (r = 0.165, p < 0.01), vigorous MET score (r = 0.247, p < 0.01) and total PA MET score (r = 0.131, p < 0.01) were significant.

CONCLUSIONS

The main finding of this study is that there is a U-shaped relationship between PA and LBP disability score in young women. A moderate level of daily physical activity and preventing body weight and fat gain should be recommended in young, female desk-job workers in order to prevent and manage low back pain.

Office workers with high effort-reward imbalance and overcommitment have greater decreases in heart rate variability over a 2-h working period

PURPOSE

High levels of workplace psychosocial factors have been associated with adverse cardiovascular outcomes, possibly through the pathway of increasing autonomic arousal. The purpose of this study was to investigate whether the workplace psychosocial factors of effort-reward imbalance (ERI) and overcommitment were associated with greater decreases in heart rate variability (HRV) across a 2-h working period in a cohort of office workers performing their own work at their own workplaces.

METHODS

Measurements of HRV in 5-min time epochs across a 2-h morning or afternoon working period, as well as self-reports of ERI and overcommitment, were collected for 91 office workers.

RESULTS

There was a negative and significant (p < 0.01) ERI*time interaction for the standard deviation of the interval between normal heart beats (SDNN), the square root of the mean squared differences of successive normal heart beats (RMSSD), and the power in the high-frequency range of the heart rate signal (HF power), and a positive and significant ERI*time interaction for the ratio of power in the low-frequency range of the heart rate signal divided by the HF power (LF/HF ratio). There was a positive and significant overcommitment*time interaction for the LF/HF ratio (p < 0.01) in the morning, and a negative and significant overcommitment*time interaction for SDNN, RMSSD, and HF power (p < 0.01) in the afternoon.

CONCLUSIONS

The results indicate that participants exposed to high levels of ERI and overcommitment exhibited a more adverse cardiovascular response (a greater decrease in HRV throughout the 2-h measurement period) compared to their colleagues with lower levels of these factors.

Sedentary behavior and health outcomes: an overview of systematic reviews

OBJECTIVE

1) To synthesize the current observational evidence for the association between sedentary behavior and health outcomes using information from systematic reviews. 2) To assess the methodological quality of the systematic reviews found.

METHODOLOGY/PRINCIPAL FINDINGS

Medline; Excerpta Medica (Embase); PsycINFO; and Web of Science were searched for reviews published up to September 2013. Additional publications were provided by Sedentary Behaviour Research Network members. The methodological quality of the systematic reviews was evaluated using recommended standard criteria from AMSTAR. For each review, improper use of causal language in the description of their main results/conclusion was evaluated. Altogether, 1,044 review titles were identified, 144 were read in their entirety, and 27 were included. Based on the systematic reviews with the best methodological quality, we found in children and adolescents, strong evidence of a relationship between time spent in sedentary behavior and obesity. Moreover, moderate evidence was observed for blood pressure and total cholesterol, self-esteem, social behavior problems, physical fitness and academic achievement. In adults, we found strong evidence of a relationship between sedentary behavior and all-cause mortality, fatal and non-fatal cardiovascular disease, type 2 diabetes and metabolic syndrome. In addition, there is moderate evidence for incidence rates of ovarian, colon and endometrial cancers.

CONCLUSIONS

This overview based on the best available systematics reviews, shows that sedentary behavior may be an important determinant of health, independently of physical activity. However, the relationship is complex because it depends on the type of sedentary behavior and the age group studied. The relationship between sedentary behavior and many health outcomes remains uncertain; thus, further studies are warranted.

European Working Time Directive and doctors' health: a systematic review of the available epidemiological evidence

OBJECTIVE

To summarise the available scientific evidence on the health effects of exposure to working beyond the limit number of hours established by the European Working Time Directive (EWTD) on physicians.

DESIGN

A systematic literature search was conducted in PubMed and EMBASE. Study selection, quality appraisal and data extraction were carried out by independent pairs of researchers using pre-established criteria.

SETTING

Physicians of any medical, surgical or community specialty, working in any possible setting (hospitals, primary healthcare, etc), as well as trainees, residents, junior house officers or postgraduate interns, were included.

PARTICIPANTS

The total number of participants was 14 338.

PRIMARY AND SECONDARY OUTCOME MEASURES

Health effects classified under the International Classification of Diseases (ICD-10).

RESULTS

Over 3000 citations and 110 full articles were reviewed. From these, 11 studies of high or intermediate quality carried out in North America, Europe and Japan met the inclusion criteria. Six studies included medical residents, junior doctors or house officers and the five others included medical specialists or consultants, medical, dental, and general practitioners and hospital physicians. Evidence of an association was found between percutaneous injuries and road traffic accidents with extended long working hours (LWH)/days or very LWH/weeks. The evidence was insufficient for mood disorders and general health. No studies on other health outcomes were identified.

CONCLUSIONS

LWH could increase the risk of percutaneous injuries and road traffic accidents, and possibly other incidents at work through the same pathway. While associations are clear, the existing evidence does not allow for an established causal or 'dose-response' relationship between LWH and incidents at work, or for a threshold number of extended hours above which there is a significantly higher risk and the hours physicians could work and remain safe and healthy. Policymakers should consider safety issues when working on relaxing EWTD for doctors.

Television viewing and time spent sedentary in relation to cancer risk: a meta-analysis

BACKGROUND

Sedentary behavior is emerging as an independent risk factor for chronic disease and mortality. However, the evidence relating television (TV) viewing and other sedentary behaviors to cancer risk has not been quantitatively summarized.

METHODS

We performed a comprehensive electronic literature search in Cochrane, EMBASE, Medline, and SciSearch databases through February 2014 for published articles investigating sedentary behavior in relation to cancer incidence. Because randomized controlled trials are difficult to perform on this topic, we focused on observational studies that met uniform inclusion criteria. Data were extracted independently by both authors and summarized using random-effects meta-analysis and meta-regression. All statistical tests were two-sided.

RESULTS

Data from 43 observational studies including a total of 68936 cancer cases were analyzed. Comparing the highest vs lowest levels of sedentary time, the relative risks (RRs) for colon cancer were 1.54 (95% confidence interval [CI] = 1.19 to 1.98) for TV viewing time, 1.24 (95% CI = 1.09 to 1.41) for occupational sitting time, and 1.24 (95% CI = 1.03 to 1.50) for total sitting time. For endometrial cancer, the relative risks were 1.66 (95% CI = 1.21 to 2.28) for TV viewing time and 1.32 (95% CI = 1.08 to 1.61) for total sitting time. A positive association with overall sedentary behavior was also noted for lung cancer (RR = 1.21; 95% CI = 1.03 to 1.43). Sedentary behavior was unrelated to cancers of the breast, rectum, ovaries, prostate, stomach, esophagus, testes, renal cell, and non-Hodgkin lymphoma.

CONCLUSIONS

Prolonged TV viewing and time spent in other sedentary pursuits is associated with increased risks of certain types of cancer.

Association of sedentary behavior time with ideal cardiovascular health: the ORISCAV-LUX study

BACKGROUND

Recently attention has been drawn to the health impacts of time spent engaging in sedentary behaviors. No studies have examined sedentary behaviors in relation to the newly defined construct of ideal cardiovascular health, which incorporates three health factors (blood pressure, total cholesterol, fasting plasma glucose) and four behaviors (physical activity, smoking, body mass index, diet). The purpose of this study was to examine associations between sedentary behaviors, including sitting time, and time spent viewing television and in front of a computer, with cardiovascular health, in a representative sample of adults from Luxembourg.

METHODS

A cross-sectional analysis of 1262 participants in the Observation of Cardiovascular Risk Factors in Luxembourg study was conducted, who underwent objective cardiovascular health assessments and completed the International Physical Activity Questionnaire. A Cardiovascular Health Score was calculated based on the number of health factors and behaviors at ideal levels. Sitting time on a weekday, television time, and computer time (both on a workday and a day off), were related to the Cardiovascular Health Score.

RESULTS

Higher weekday sitting time was significantly associated with a poorer Cardiovascular Health Score (p = 0.002 for linear trend), after full adjustment for age, gender, education, income and occupation. Television time was inversely associated with the Cardiovascular Health Score, on both a workday and a day off (p = 0.002 for both). A similar inverse relationship was observed between the Cardiovascular Health Score and computer time, only on a day off (p = 0.04).

CONCLUSION

Higher time spent sitting, viewing television, and using a computer during a day off may be unfavorably associated with ideal cardiovascular health.

Ethnic disparities in objectively measured physical activity may be due to occupational activity

OBJECTIVES

We examined whether Mexican American adults report occupations that involve higher levels of objectively assessed physical activity compared with Non-Hispanic White and Black adults, and if the differences were independent of income.

METHODS

Data from the 2003-2004 National Health and Nutrition Examination Survey (NHANES; N=2707) were analyzed in 2012-2013. An existing classification scheme was used to classify self-reported occupation as sedentary, low-active, or moderately active. From NHANES accelerometer data, proportion of wear time was stratified by intensity.

RESULTS

A dose-response relationship was found such that workers in more active occupations spent more time in light-intensity activity and less time engaged in sedentary activities. The findings did not suggest a compensation effect for moderate-to-vigorous intensity physical activity. Mexican American adults engaged in more activity than Non-Hispanic Black or White adults for incomes between $10,000 and $64,999.

CONCLUSIONS

Mexican American adults may have higher total physical activity levels in NHANES because of occupational activity, particularly among lower income households. To the extent that light-intensity activity may provide health benefits, occupational activity may partly explain the Hispanic paradox.

Exposure to nature versus relaxation during lunch breaks and recovery from work: development and design of an intervention study to improve workers' health, well-being, work performance and creativity

Background

The objective of this research project is to understand and to improve workers’ recovery from work stress. Although recovery during lunch breaks is the most common within-workday break, it has received only minor research attention. Therefore, we will study whether lunch breaks including a relaxation session or exposure to nature have more favorable outcomes than usually spent lunch breaks concerning: a) recovery processes, b) health, c) well-being, d) job performance and e) creativity. We approach recovery by combining the theoretical frameworks of work and environmental psychology.

Methods/Design

We conduct an intervention study in a sample of 268 knowledge-workers who engage in different lunch break activities for 15-minutes per day, two weeks in a row. We randomly assign participants to three experimental conditions: 1) exposure to nature, 2) relaxation and 3) control group (lunch break spent as usual). Online questionnaires before and after the intervention assess long term changes regarding recovery processes and the major outcome variables. Before, during and after the intervention, SMS and paper-pencil questionnaires measure the same constructs four times a day with fewer items. We also measure blood pressure and collect saliva samples to map cortisol excretion across the intervention period. A timed experimental task (i.e., the Alternative Uses Task) is used to examine differences in creativity between the three groups after the intervention period.

Discussion

By combining the knowledge of work and environmental psychology about recovery and restorative experiences, by merging three recovery perspectives (settings, processes, and outcomes) and by using data triangulation, we produce valid results that broaden our view on mechanisms underlying recovery and enhance our understanding about their links to psychological, behavioural and physiological outcomes, resulting in a more comprehensive picture of work stress recovery in general.

Trial registration

ClinicalTrials.gov Protocol Registration System NCT02124837. Registered 24 April 2014.

Correlation between pedometer and the Global Physical Activity Questionnaire on physical activity measurement in office workers

Background

This study aimed to examine the correlation of physical activity levels assessed by pedometer and those by the Global Physical Activity Questionnaire (GPAQ) in a population of office workers.

Methods

A cross-sectional study was conducted on 320 office workers. A self-administered questionnaire was distributed to each office worker by hand. Physical activity level was objectively assessed by a pedometer for 7 consecutive days and subjectively assessed by the GPAQ. Based on the pedometer and GPAQ outcomes, participants were classified into 3 groups: inactive, moderately active, and highly active.

Results

No correlation in the physical activity level assessed by the pedometer and GPAQ was found (r_s = .08, P = 0.15). When considering the pedometer as the criterion for comparison, 65.3% of participants had underestimated their physical activity level using the GPAQ, whereas 9.3% of participants overestimated their physical activity level.

Conclusions

Physical activity level in office workers assessed by a subjective measure was greatly different from assessed by an objective tool. Consequently, research on physical activity level, especially in those with sedentary lifestyle, should consider using an objective measure to ensure that it closely reflects a person’s physical activity level.

Duration of television viewing and bone mineral density in Chinese women

Studies on the relationship between television (TV) viewing and bone mineral density (BMD) in adults are limited. The purpose of this study was to examine whether longer duration of TV viewing increased the risk of lower BMD in Chinese women. A total of 626 female adults were voluntarily recruited into the study. Anthropometric measurements were obtained using standard procedures. Body composition including total body and regional BMD was estimated using dual-energy X-ray absorptiometry. The duration of TV viewing was categorized into 4 groups: <1 h, 1 to <2 h, 2 to <3 h, and ≥3 h. Multiple linear regression models were applied to analyze the associations between duration of TV viewing and total and regional BMD in all subjects and in subjects stratified by age of 45 years, respectively. After adjusting for age, BMI, alcohol use, smoking, education, income, urbanicity, leisure time physical activity, occupational physical activity, and menopause, the significant trend of pelvic BMD across categories of TV viewing was observed in all subjects (p < 0.05). Further analysis revealed that women aged <45 years, the 1 to <2 h group, the 2 to <3 h group, and the ≥3 h group were significantly associated with lower total body and regional BMD compared to women aged <45 years in the <1 h group. We concluded that the duration of TV viewing was negatively associated with BMD in Chinese women, especially in those aged 18-44 years. It might be sensible to reduce TV viewing time to prevent bone loss in young women.

Inverse effects of midlife occupational and leisure time physical activity on mobility limitation in old age--a 28-year prospective follow-up study

OBJECTIVES

To evaluate in a sample of initially middle-aged municipal employees whether leisure time (LPA) or occupational physical activity (OPA) was associated with mobility limitation (ML) in old age.

DESIGN

Prospective population-based follow-up.

SETTING

Municipalities in Finland.

PARTICIPANTS

Public sector employees from the Finnish Longitudinal Study on Municipal Employees (FLAME) initially aged 44 to 58 (N = 5,200).

MEASUREMENTS

Baseline data were collected in 1981, including LPA (average exercise within previous year: inactive (no exercise), moderate (some form of exercise ≤ 1 time per week), vigorous (brisk exercise ≥ 1 time per week)) and OPA (usual activities at work within previous year: light (light work sitting, standing, or moving around), moderate (moderate work moving around), vigorous (heavy physical work)). Number of MLs was assessed using a questionnaire (8 items) in 1985, 1992, 1997, and 2009; the latest mobility score available for each subject was used for analyses. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for LPA and OPA predicting ML were estimated in a joint Poisson regression model adjusted for survival data; the other type of PA; and sociodemographic, socioeconomic, and health-related factors.

RESULTS

Mean age at baseline was 50.3 ± 3.6; 56.9% of participants were female. Participants with vigorous OPA in midlife had greater risk of a unit increase in ML in old age than those with light OPA (fully adjusted IRR = 1.09, 95% CI = 1.03-1.16). Participants with vigorous LPA had lower risk of ML than inactive participants (fully adjusted IRR = 0.81, 95% CI = 0.76-0.86).

CONCLUSION

Findings suggest that LPA and OPA in midlife have independent, inverse effects on mobility in old age in terms of a harmful effect of vigorous OPA and a protective effect of vigorous LPA.

McEachan R. Are incremental changes in physical activity and sedentary behaviours associated with improved employee health?

Purpose

– The workplace offers an ideal setting for facilitating physical activity and reducing sedentary behaviours. Understanding employees’ current health behaviours is required to inform appropriate, tailored, health promotion interventions. The purpose of this paper is to compare the physical activity and sedentary behaviours over 12 months of employees within and across five UK organisations. The paper also explores the association of these health behaviours with objective and self-reported health outcomes; and investigates the association between physical activity and sedentary behaviours.

Design/methodology/approach

– Self-reported physical activity and sedentary behaviours were recorded at four time points (baseline, three, six, 12 months). BMI, per cent body fat, waist circumference, blood pressure and resting heart rate were collected in health checks (baseline, 12 months). Well-being and health were collected via questionnaire.

Findings

– Low physical activity and high sedentariness were evident. Sitting levels varied by occupational role and organisation. More activity was associated with improved health outcomes; no association was evident for sedentary behaviour. No direct effects of occupational role or organisation on health outcomes emerged after accounting for physical activity/sedentary behaviours. Physical activity and sedentary levels were weakly associated.

Practical implications

– The low activity levels are of particular concern as linked to health outcomes for this sample. The weak association between behaviours suggests worksite interventions should target both behaviours.

Originality/value

– This study provides insight into both the physical activity and sedentary behaviours of employees of large UK employers across different occupational sectors over 12 months; importantly it is informed by the most recent guidance for these health behaviours.

Daily sitting time and all-cause mortality: a meta-analysis

Objective

To quantify the association between daily total sitting and all-cause mortality risk and to examine dose-response relationships with and without adjustment for moderate-to-vigorous physical activity.

Methods

Studies published from 1989 to January 2013 were identified via searches of multiple databases, reference lists of systematic reviews on sitting and health, and from authors’ personal literature databases. We included prospective cohort studies that had total daily sitting time as a quantitative exposure variable, all-cause mortality as the outcome and reported estimates of relative risk, or odds ratios or hazard ratios with 95% confidence intervals. Two authors independently extracted the data and summary estimates of associations were computed using random effects models.

Results

Six studies were included, involving data from 595,086 adults and 29,162 deaths over 3,565,569 person-years of follow-up. Study participants were mainly female, middle-aged or older adults from high-income countries; mean study quality score was 12/15 points. Associations between daily total sitting time and all-cause mortality were not linear. With physical activity adjustment, the spline model of best fit had dose-response HRs of 1.00 (95% CI: 0.98-1.03), 1.02 (95% CI: 0.99-1.05) and 1.05 (95% CI: 1.02-1.08) for every 1-hour increase in sitting time in intervals between 0-3, >3-7 and >7 h/day total sitting, respectively. This model estimated a 34% higher mortality risk for adults sitting 10 h/day, after taking physical activity into account. The overall weighted population attributable fraction for all-cause mortality for total daily sitting time was 5.9%, after adjusting for physical activity.

Conclusions

Higher amounts of daily total sitting time are associated with greater risk of all-cause mortality and moderate-to-vigorous physical activity appears to attenuate the hazardous association. These findings provide a starting point for identifying a threshold on which to base clinical and public health recommendations for overall sitting time, in addition to physical activity guidelines.

Participatory workplace interventions can reduce sedentary time for office workers--a randomised controlled trial

BACKGROUND

Occupational sedentary behaviour is an important contributor to overall sedentary risk. There is limited evidence for effective workplace interventions to reduce occupational sedentary time and increase light activity during work hours. The purpose of the study was to determine if participatory workplace interventions could reduce total sedentary time, sustained sedentary time (bouts >30 minutes), increase the frequency of breaks in sedentary time and promote light intensity activity and moderate/vigorous activity (MVPA) during work hours.

METHODS

A randomised controlled trial (ANZCTR NUMBER: ACTN12612000743864) was conducted using clerical, call centre and data processing workers (n = 62, aged 25-59 years) in 3 large government organisations in Perth, Australia. Three groups developed interventions with a participatory approach: 'Active office' (n = 19), 'Active Workstation' and promotion of incidental office activity; 'Traditional physical activity' (n = 14), pedometer challenge to increase activity between productive work time and 'Office ergonomics' (n = 29), computer workstation design and breaking up computer tasks. Accelerometer (ActiGraph GT3X, 7 days) determined sedentary time, sustained sedentary time, breaks in sedentary time, light intensity activity and MVPA on work days and during work hours were measured before and following a 12 week intervention period.

RESULTS

For all participants there was a significant reduction in sedentary time on work days (-1.6%, p = 0.006) and during work hours (-1.7%, p = 0.014) and a significant increase in number of breaks/sedentary hour on work days (0.64, p = 0.005) and during work hours (0.72, p = 0.015); there was a concurrent significant increase in light activity during work hours (1.5%, p = 0.012) and MVPA on work days (0.6%, p = 0.012).

CONCLUSIONS

This study explored novel ways to modify work practices to reduce occupational sedentary behaviour. Participatory workplace interventions can reduce sedentary time, increase the frequency of breaks and improve light activity and MVPA of office workers by using a variety of interventions.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTN12612000743864.

Lack of exercise is a major cause of chronic diseases

Chronic diseases are major killers in the modern era. Physical inactivity is a primary cause of most chronic diseases. The initial third of the article considers: activity and prevention definitions; historical evidence showing physical inactivity is detrimental to health and normal organ functional capacities; cause versus treatment; physical activity and inactivity mechanisms differ; gene-environment interaction (including aerobic training adaptations, personalized medicine, and co-twin physical activity); and specificity of adaptations to type of training. Next, physical activity/exercise is examined as primary prevention against 35 chronic conditions [accelerated biological aging/premature death, low cardiorespiratory fitness (VO2max), sarcopenia, metabolic syndrome, obesity, insulin resistance, prediabetes, type 2 diabetes, nonalcoholic fatty liver disease, coronary heart disease, peripheral artery disease, hypertension, stroke, congestive heart failure, endothelial dysfunction, arterial dyslipidemia, hemostasis, deep vein thrombosis, cognitive dysfunction, depression and anxiety, osteoporosis, osteoarthritis, balance, bone fracture/falls, rheumatoid arthritis, colon cancer, breast cancer, endometrial cancer, gestational diabetes, pre-eclampsia, polycystic ovary syndrome, erectile dysfunction, pain, diverticulitis, constipation, and gallbladder diseases]. The article ends with consideration of deterioration of risk factors in longer-term sedentary groups; clinical consequences of inactive childhood/adolescence; and public policy. In summary, the body rapidly maladapts to insufficient physical activity, and if continued, results in substantial decreases in both total and quality years of life. Taken together, conclusive evidence exists that physical inactivity is one important cause of most chronic diseases. In addition, physical activity primarily prevents, or delays, chronic diseases, implying that chronic disease need not be an inevitable outcome during life.

Evaluation of ergonomic and education interventions to reduce occupational sitting in office-based university workers: study protocol for a randomized controlled trial

BACKGROUND

Prolonged sitting is a specific occupational hazard in office workers. There is growing evidence that prolonged sitting is detrimental to metabolic health. The aim of this study is to determine whether providing office workers with education along with adjustable sit-stand workstations leads to reduction in sitting behavior.

METHODS/DESIGN

A randomized control trial (RCT) with three groups (one control group and two intervention groups) will be conducted in an office workplace setting. The education intervention group will receive an education package that encourages reduction in sitting behaviors. The sit-stand desk intervention group will receive the same education package along with an adjustable sit-stand desk. Participants will be included in the study if they are currently employed in a full-time academic or administrative role that involves greater than 15 hours per week or greater than 4 hours per day computer-based work. Baseline data will include participant's age, gender, weight, height, smoking habit, employment position, level of education, and baseline self-reported leisure time physical activity. The primary outcome is the average daily sedentary time during work hours, measured by an accelerometer. Participant recruitment commenced in March 2013 and will be completed by December 2013.

DISCUSSION

This study will determine whether providing office workers with an adjustable sit-stand desk and individually targeted education, or education alone, is more effective in decreasing sitting behaviors than no intervention.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12613000366752.

Does an 'activity-permissive' workplace change office workers' sitting and activity time?

Introduction

To describe changes in workplace physical activity, and health-, and work-related outcomes, in workers who transitioned from a conventional to an ‘activity-permissive’ workplace.

Methods

A natural pre-post experiment conducted in Vancouver, Canada in 2011. A convenience sample of office-based workers (n=24, 75% women, mean [SD] age = 34.5 [8.1] years) were examined four months following relocation from a conventional workplace (pre) to a newly-constructed, purpose-built, movement-oriented physical environment (post). Workplace activity- (activPAL3-derived stepping, standing, and sitting time), health- (body composition and fasting cardio-metabolic blood profile), and work- (performance; job satisfaction) related outcomes were measured pre- and post-move and compared using paired t-tests.

Results

Pre-move, on average (mean [SD]) the majority of the day was spent sitting (364 [43.0] mins/8-hr workday), followed by standing (78.2 [32.1] mins/8-hr workday) and stepping (37.7 [15.6] mins/8-hr workday). The transition to the ‘activity-permissive’ workplace resulted in a significant increase in standing time (+18.5, 95% CI: 1.8, 35.2 mins/8-hr workday), likely driven by reduced sitting time (-19.7, 95% CI: -42.1, 2.8 mins/8-hr workday) rather than increased stepping time (+1.2, 95% CI: -6.2, 8.5 mins/8-hr workday). There were no statistically significant differences observed in health- or work-related outcomes.

Discussion

This novel, opportunistic study demonstrated that the broader workplace physical environment can beneficially impact on standing time in office workers. The long-term health and work-related benefits, and the influence of individual, organizational, and social factors on this change, requires further evaluation.

Desk-based occupational sitting patterns: weight-related health outcomes

BACKGROUND

Prolonged, uninterrupted sitting time is associated with poor health outcomes. As most sitting time occurs at work, accurate, objective measurement of occupational sitting patterns is required to fully understand its effects on employee health.

PURPOSE

The purpose of this study was to examine associations of desk-based sitting patterns with waist circumference (WC) and BMI.

METHODS

Participants were full-time, office-based employees (N=105; mean age 40.9±11.5 years; BMI 26.1±3.9; 65% women). Sitting patterns (total desk-based sitting time and number of times employees got up from their desk) were assessed for 5 days using an objective measure of desk-based sitting: the sitting pad. WC, height, and weight were measured, and BMI was calculated. Associations of sitting patterns with WC and BMI were tested using logistic regression models. Data were collected and analyzed in 2011-2012.

RESULTS

Those with high levels of sitting time at their desk were 2.7 times (95% CI=1.3, 6.3) more likely to have WC ≥94 cm (men) and ≥80 cm (women), and 9.0 times (95% CI=1.9, 41.9) more likely to have BMI ≥30 than those with lower sitting time. There were no associations between the number of times employees got up from sitting at their desk and WC or BMI.

CONCLUSIONS

High levels of desk-based sitting time were associated with an increased likelihood of negative weight-related health outcomes, whereas frequency of getting up from sitting at the desk was not.

The effects of a lifestyle intervention on leisure-time sedentary behaviors in adults at risk: the Hoorn Prevention Study, a randomized controlled trial

OBJECTIVE

This study set out to assess the short- and long-term effects of a primary care-based lifestyle intervention on different domains of leisure-time sedentary behaviors in Dutch adults at risk of type 2 diabetes and cardiovascular diseases.

METHODS

Between 2007 and 2009, adults (n=622) at risk were randomly assigned to a counseling intervention aimed at adopting healthy lifestyle behaviors, or a control group that only received health brochures. Follow-up measures were done after 6, 12 and 24months. Linear regression analysis was used to examine between-group differences in self-report minutes per day sedentary behaviors, adjusted for baseline values. Stratified analyses were performed for sex and educational attainment.

RESULTS

Seventy-nine percent (n=490) of participants completed the last follow-up. Mean baseline sedentary behaviors were 254.6min per day (SD=136.2). Intention-to-treat analyses showed no significant differences in overall or domain-specific sedentary behaviors between the two groups at follow-up. Stratified analyses for educational attainment revealed a small and temporary between-group difference in favor of the intervention group, in those who finished secondary school.

CONCLUSIONS

A primary care-based general lifestyle intervention was not more effective in reducing leisure-time sedentary behaviors than providing brochures in adults at risk for chronic diseases.

Are sitting occupations associated with increased all-cause, cancer, and cardiovascular disease mortality risk? A pooled analysis of seven British population cohorts

Background

There is mounting evidence for associations between sedentary behaviours and adverse health outcomes, although the data on occupational sitting and mortality risk remain equivocal. The aim of this study was to determine the association between occupational sitting and cardiovascular, cancer and all-cause mortality in a pooled sample of seven British general population cohorts.

Methods

The sample comprised 5380 women and 5788 men in employment who were drawn from five Health Survey for England and two Scottish Health Survey cohorts. Participants were classified as reporting standing, walking or sitting in their work time and followed up over 12.9 years for mortality. Data were modelled using Cox proportional hazard regression adjusted for age, waist circumference, self-reported general health, frequency of alcohol intake, cigarette smoking, non-occupational physical activity, prevalent cardiovascular disease and cancer at baseline, psychological health, social class, and education.

Results

In total there were 754 all-cause deaths. In women, a standing/walking occupation was associated with lower risk of all-cause (fully adjusted hazard ratio [HR] = 0.68, 95% CI 0.52–0.89) and cancer (HR = 0.60, 95% CI 0.43–0.85) mortality, compared to sitting occupations. There were no associations in men. In analyses with combined occupational type and leisure-time physical activity, the risk of all-cause mortality was lowest in participants with non-sitting occupations and high leisure-time activity.

Conclusions

Sitting occupations are linked to increased risk for all-cause and cancer mortality in women only, but no such associations exist for cardiovascular mortality in men or women.

Separate and joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors in working adults: a cross-sectional study

BACKGROUND

The workplace is a main setting for prolonged sitting for some occupational groups. Convincing evidence has recently accumulated on the detrimental cardio-metabolic health effects of leisure-time sitting. Yet, much less is known about occupational sitting, and the potential health risk attached compared to leisure-time sitting.

OBJECTIVE

To explore the separate and joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors in working adults.

METHODS

All working adults (N = 2544) from the Health2006, a Danish population-based study, were included in this cross-sectional study. Participants reported hours of sitting during work, during leisure-time along with socio-demographic and behavioral characteristics, including physical activity. Cardio-metabolic risk factors (waist circumference, body mass index, body fat percentage, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, insulin, hemoglobin A1c and plasma glucose) were measured. Associations were explored by linear regression for leisure-time, occupational, and overall sitting time.

RESULTS

Statistically significant (p<.05) detrimental associations of leisure-time sitting were observed with all cardio-metabolic risk factors, except hemoglobin A1c and plasma glucose. Similarly, occupational sitting time was significantly detrimentally associated with HDL cholesterol, triglycerides, and insulin. For categories of sitting time, a joint adverse association of sitting much during both work-time and leisure-time was observed.

CONCLUSION

The associations of occupational sitting time with cardio-metabolic risk factors were fewer and weaker compared to leisure-time sitting. Yet, the joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors were higher than the separate. Our findings amplify the need for further focus in this area prior to making assumptions about equivalent health risks across sedentary behaviors. To our knowledge, this is the first study to contrast the deleterious associations of prolonged occupational and leisure-time sitting, both separately and jointly.

Study protocol: the relation of birth weight and infant growth trajectories with physical fitness, physical activity and sedentary behavior at 8-9 years of age - the ABCD study

BACKGROUND

Low birth weight and accelerated infant growth have been identified as independent risk factors for childhood and adult obesity and cardiovascular disease. This led to the 'Developmental Origins of Health and Disease' (DOHaD) hypothesis, stating that environmental factors during pregnancy and early postnatal life affect disease risk in later life. There is growing evidence that perinatal factors may influence adult health through the programming of energy balance regulation, including sedentary behavior and physical activity. The present study focuses on the influence of birth weight and infant growth on physical fitness, physical activity and sedentary behavior in 8-9 year old children, as this might partly explain the higher obesity and cardiovascular risk associated with low birth weight and accelerated infant growth. In addition, this study provides the opportunity for a validation study of a linguistic and cross-cultural translated physical activity questionnaire compared to accelerometer data. This article describes the study protocol for this study.

METHODS/DESIGN

This is a study embedded in the Amsterdam Born Children and their Development (ABCD) birth cohort. In 200 children of Dutch ethnicity, physical fitness, physical activity and sedentary behavior were assessed at age 8-9. We measured aerobic fitness using the 20 meter multistage shuttle run test, and neuromuscular fitness using the standing broad jump and handgrip strength test. Sedentary behavior and physical activity levels were measured using accelerometry. All children also completed a translated physical activity questionnaire, the scores of which will be compared to accelerometry data to assess the construct validity of the questionnaire in Dutch school-aged children.

DISCUSSION

This study will be the first population-based prospective cohort study to address the association of both prenatal and postnatal growth with physical fitness and objectively-assessed physical activity and sedentary behavior. This will contribute to a better understanding of the way perinatal growth relate to lifestyle and obesity in later life. The results may guide both future studies in the field of DOHaD, and public health strategies in the prevention of childhood obesity.

Rotating shift-work as an independent risk factor for overweight Italian workers: a cross-sectional study

Background

A job-related factor is attracting a growing interest as a possible determinant of body weight gain in shift-workers.

Objective

The aim of the study was to reinvestigate the issue of overweight between rotating shift workers and daytime workers, taking into consideration possible confounding covariate factors.

Methods

This is a cross-sectional study, conducted by reviewing data from subjects participating in an occupational surveillance program in 2008. Participants answered a self-administered questionnaire to retrieve information about socio-demographic factors and working conditions (job schedule type, job-related physical activity, time in job), subjective health status, health care visits during the previous year, and lifestyle factors (dietary habits, leisure time physical activity, alcohol consumption). Participants underwent a medical examination for measurement of BMI, and acquisition of medical history.

Results

Compared to daytime workers (N = 229), rotating shift workers (N = 110) displayed higher BMI (mean BMI was 27.6±3.9 and 26.7±3.6 for shift workers, and daytime workers, respectively; p<0.05). Logistic regression analysis allowed to highlight the role of rotating shift-work as an independent risk factor for increased body weight (OR 1.93, 95%CI 1.01–3.71), being aged between 35 and 54 years was a major determinant of increased BMI (OR 2.39, 95%CI 1.14–5.00). In addition, family history of obesity was the strongest determinant of overweight/obesity (OR 9.79, 95%CI 1.28–74.74). Interestingly, no significant association was found between overweight and other potentially relevant factors, such as diet quality and food choices, alcohol consumption, levels of occupational and leisure-time physical activity.

Conclusions

Present findings seem to support the notion that rotating shift work is an independent risk factor for overweight, regardless of workers' dietary habits and physical activity levels.

Sedentary behaviour and risk of mortality from all-causes and cardiometabolic diseases in adults: evidence from the HUNT3 population cohort

BACKGROUND

Sedentary behaviour is a potential risk factor for chronic-ill health and mortality, that is, independent of health-enhancing physical activity. Few studies have investigated the risk of mortality associated with multiple contexts of sedentary behaviour.

OBJECTIVE

To examine the prospective associations of total sitting time, TV-viewing time and occupational sitting with mortality from all causes and cardiometabolic diseases.

METHODS

Data from 50,817 adults aged ≥20 years from the Nord-Trøndelag Health Study 3 (HUNT3) in 2006-2008 were linked to the Norwegian Cause of Death Registry up to 31 December 2010. Cox proportional hazards models examined all-cause and cardiometabolic disease-related mortality associated with total sitting time, TV-viewing and occupational sitting, adjusting for multiple potential confounders including physical activity.

RESULTS

After mean follow-up of 3.3 years (137,315.8 person-years), 1068 deaths were recorded of which 388 were related to cardiometabolic diseases. HRs for all-cause mortality associated with total sitting time were 1.12 (95% CI 0.89 to 1.42), 1.18 (95% CI 0.90 to 1.57) and 1.65 (95% CI 1.24 to 2.21) for total sitting time 4-<7, 7-<10 and ≥10 h/day, respectively, relative to <4 h/day after adjusting for confounders (p-trend=0.001). A similar pattern of associations was observed between total sitting time and mortality from cardiometabolic diseases, but TV-viewing time and occupational sitting showed no or borderline significant associations with all-cause or cardiometabolic disease-related mortality over the same follow-up period.

CONCLUSIONS

Total sitting time is associated with all-cause and cardiometabolic disease-related mortality in the short term. However, prolonged sitting in specific contexts (ie, watching TV, at work) do not adversely impact health in the same timeframe. These findings suggest that adults should be encouraged to sit less throughout the day to reduce their daily total sitting time.

"Thinking on your feet": A qualitative evaluation of sit-stand desks in an Australian workplace

Background

Epidemiological research has established sitting as a new risk factor for the development of non-communicable chronic disease. Sit-stand desks have been proposed as one strategy to reduce occupational sedentary time. This formative research study evaluated the acceptability and usability of manually and electrically operated sit-stand desks in a medium-sized government organisation located in Sydney, Australia.

Methods

Sitting time pre- and three months post -installation of the sit-stand desks was measured using validated self-report measures. Additionally, three group interviews and one key-informant interview were conducted with staff regarding perceptions about ease of, and barriers to, use and satisfaction with the sit-stand desks. All interviews were recorded, transcribed and analysed for themes regarding usability and acceptability.

Results

Of 31 staff, 18 completed baseline questionnaires, and 13 completed follow-up questionnaires. The median proportion of sitting time for work was 85% (range 50%-95%) at baseline and 60% (range 10%-95%) at follow-up. Formal statistical testing of paired data (n=11) showed that the change from baseline to follow-up in time spent sitting (mean change=1.7 hours, p=.014) was statistically significant. From the qualitative data, reasons given for initiating use of the desks in the standing position were the potential health benefits, or a willingness to experiment or through external prompting. Factors influencing continued use included: concern for, and experience of, short and long term health impacts; perceived productivity whilst sitting and standing; practical accommodation of transitions between sitting and standing; electric or manual operation height adjustment. Several trajectories in patterns of initiation and continued use were identified that centered on the source and timing of commitment to using the desk in the standing position.

Conclusions

Sit-stand desks had high usability and acceptability and reduced sitting time at work. Use could be promoted by emphasizing the health benefits, providing guidance on appropriate set-up and normalizing standing for work-related tasks.

Joint association of sitting time and physical activity with metabolic risk factors among middle-aged Malays in a developing country: a cross-sectional study

Background

Prolonged sitting is associated with increased weight and higher risks for abdominal obesity, dyslipidaemia, hyperglycaemia and hypertension among the adult population. This has been well documented in the West, but studies on these associations are lacking in developing countries, including Malaysia.

Objective

This cross-sectional study aimed to examine the joint association of sitting time and physical activity with metabolic risk factors among middle-aged working adults.

Methodology

A total of 686 Malay men and women participated (mean age 45.9±6.5 years). Metabolic syndrome was diagnosed from the modified NCEP ATP III criteria. Self-reported sitting time was obtained with the validated Malay version of the International Physical Activity Questionnaire. Participants were asked about their time spent sitting during travel in a motor vehicle, e.g., car, motorcycle or bus, over the preceding 7 days. Logistic regression was used to estimate the odds ratio with the confidence interval for the combined effects of sitting quartiles and physical activity categories with metabolic risk factors.

Results/Significance

The prevalence of metabolic syndrome among our participants was 31.9%. Their average total sitting time (including transportation) was 7.6±2.4 h/day. After we adjusted for gender and educational level, higher sitting quartiles and physically inactive groups were associated with higher odds for metabolic syndrome compared with the referent group (sitting <6 h/day and physically active). In the physically active stratum, the odds for metabolic syndrome in participants who sat ≥9.3 h/day was 3.8 times that of participants who sat <6 h/day. Both higher sitting quartiles and insufficient physical activity were associated with adverse effects on abdominal obesity, hypertriglyceridemia and hyperglycaemia.

Conclusion

In joint analyses of sitting time and physical activity, higher sitting time and insufficient physical activity were deleteriously associated with odds for metabolic risk factors in middle-aged Malay men and women.

The contribution of office work to sedentary behaviour associated risk

BACKGROUND

Sedentary time has been found to be independently associated with poor health and mortality. Further, a greater proportion of the workforce is now employed in low activity occupations such as office work. To date, there is no research that specifically examines the contribution of sedentary work to overall sedentary exposure and thus risk. The purpose of the study was to determine the total exposure and exposure pattern for sedentary time, light activity and moderate/vigorous physical activity (MVPA) of office workers during work and non-work time.

METHODS

50 office workers from Perth, Australia wore an Actical (Phillips, Respironics) accelerometer during waking hours for 7 days (in 2008-2009). Participants recorded wear time, waking hours, work hours and daily activities in an activity diary. Time in activity levels (as percentage of wear time) during work and non-work time were analysed using paired t-tests and Pearson's correlations.

RESULTS

Sedentary time accounted for 81.8% of work hours (light activity 15.3% and MVPA 2.9%), which was significantly greater than sedentary time during non-work time (68.9% p < 0.001). Office workers experienced significantly more sustained sedentary time (bouts >30 minutes) and significantly less brief duration (0-10 minutes) light intensity activity during work hours compared to non-work time (p < 0.001). Further, office workers had fewer breaks in sedentary time during work hours compared to non-work time (p < 0.001).

CONCLUSIONS

Office work is characterised by sustained sedentary time and contributes significantly to overall sedentary exposure of office workers.

Non-occupational sedentary behaviors: population changes in The Netherlands, 1975-2005

BACKGROUND

Evidence is accumulating that sedentary behaviors have detrimental health effects. Comprehensive data on population changes in various sedentary behaviors over time are scarce.

PURPOSE

This study aimed to determine changes in non-occupational sedentary behaviors in the Dutch adult population between 1975 and 2005.

METHODS

The National Time Use Survey of the Netherlands was used, which has been collected in 5-year intervals since 1975 (seven time points, n range=1017-2845). Adult participants completed a 7-day time-use diary in which they recorded their primary activity in 15-minute intervals throughout or at the end of the day. A validated method was used to determine time spent in various non-occupational sedentary behaviors. Population-weighted analyses determining changes over time in various sedentary behaviors were carried out in 2011 and 2012.

RESULTS

Between 1975 and 2005, the proportion of non-occupational time spent sedentary remained relatively constant at ~60%. However, absolute time decreased, because of a 4.7-hour/week increase in occupational time. Sedentary occupational time could not be studied but has likely increased over these 3 decades. Most non-occupational sedentary behavior was during leisure, and the proportion of sedentary leisure time that comes from screen time increased from 26% in 1975 to 43% in 2005. Between 1975 and 2005, sedentary transport increased by 2 hours/week.

CONCLUSIONS

The nature and distribution of sedentary behaviors in the Dutch adult population changed substantially over 3 decades. Screen-based activities are playing an increasingly dominant role.

Effects of eight weeks of resistance training on the risk factors of metabolic syndrome in overweight /obese women - "A Pilot Study"

BACKGROUND

The purpose of the present study was to examine the effects of eight weeks of resistance training (RT) on anthropometric, cardiovascular and biochemical risk factors of metabolic syndrome (MetS), and neuromuscular variables on overweight/obese women.

METHODS

Fourteen middle-aged (33.9 ± 8.6 years) overweight/obese women (body mass index - BMI 29.6 ± 4.1 kg/m2) underwent 24 sessions (3 times/week) of a whole body RT program with 3 sets of 8-12 repetitions maximum (RM). The following variables were evaluated: maximum strength on chest press and frontal lat pull-down; isometric hand-grip strength; biceps brachii (BB) and rectus femoris (RF) muscle thickness, body mass; BMI; body adiposity index (BAI); waist, hip and neck circumferences; visceral fat volume; blood glucose; glycated hemoglobin (HbA1c); insulin; HDL-C and triglycerides.

RESULTS

There was an increase of chest press (from 52.9 ± 9.7 to 59.8 ± 7.7 kg; P = 0.02) and front lat pull-down (from 51.5 ± 7.5 to 57.6 ± 9.2 kg; P = 0.01) muscle strength, isometric handgrip (P = 0.02) and RF muscle thickness (from 42.2 ± 8.5 to 45.1 ± 7.3 mm; P = 0.02) after the 8 week RT program. There were no statistically significant alterations on plasma glucose, HbA1c, insulin, triglycerides, HDL-C, anthropometric indexes and BB muscle thickness (p > 0.05).

CONCLUSIONS

A RT program without caloric restriction promotes an increase on muscle thickness and strength, with no effects on risk factors of MetS in overweight/obese women.

The psychosocial work environment and incident diabetes in Ontario, Canada

BACKGROUND

Relatively few longitudinal studies have explored the relationship between psychosocial work conditions and diabetes incidence. Given the increasing global burden of diabetes this is an important area for public health research.

AIMS

To examine the relationships between dimensions of the psychosocial work environment on the subsequent incidence of diabetes among men and women in Ontario, Canada over a 9 year period.

METHODS

We used data from Ontario respondents (35 to 60 years of age) to the 2000-01 Canadian Community Health Survey linked to the Ontario Health Insurance Plan database for physician services and the Canadian Institute for Health Information Discharge Abstract Database for hospital admissions. Our sample of actively employed labour market participants with no previous diagnoses for diabetes was followed for a 9 year period to ascertain incident diabetes.

RESULTS

There were 7443 participants. Low levels of job control were associated with an increased risk of diabetes among women, but not among men. Counter to our hypotheses high levels of social support were also associated with increased diabetes risk among women, but not among men. No relationship was found between any psychosocial work measure and risk of diabetes among men.

CONCLUSIONS

Given the increasing prevalence of diabetes worldwide, job control could potentially be an import ant modifiable risk factor to reduce the incidence of diabetes among female, but not among male, workers. More research is needed to understand the pathways through which low social support may protect against the development of diabetes.

Associations of children's independent mobility and active travel with physical activity, sedentary behaviour and weight status: a systematic review

Health benefits from children's independent mobility and active travel beyond school travel are largely unexplored.

OBJECTIVES

This review synthesized the evidence for associations of independent mobility and active travel to various destinations with physical activity, sedentary behaviour and weight status.

DESIGN

Systematic review.

METHODS

A systematic search in six databases (PubMed, Scopus, CINAHL, SportDiscus, PsychInfo, TRIS) for papers published between January 1990 and March 2012 was undertaken, focussing on children aged 3-18 years. Study inclusion and methodological quality were independently assessed by two reviewers.

RESULTS

52 studies were included. Most studies focussed solely on active travel to and/or from school, and showed significant positive associations with physical activity. The same relationship was detected for active travel to leisure-related places and independent mobility with physical activity. An inverse relationship between active travel to school and weight status was evident but findings were inconsistent. Few studies examined correlations between active travel to school and self-reported screen-time or objectively measured sedentary behaviour, and findings were unclear.

CONCLUSIONS

Studies on independent mobility suggested that children who have the freedom to play outdoors and travel actively without adult supervision accumulate more physical activity than those who do not. Further investigation of children's active travel to leisure-related destinations, measurement of diverse sedentary behaviour beyond simply screen-based activities, and consistent thresholds for objectively measured sedentary behaviour in children will clarify the inconsistent evidence base on associations of active travel with sedentary behaviour and weight status.

Sedentary time in adults and the association with diabetes, cardiovascular disease and death: systematic review and meta-analysis

AIMS/HYPOTHESIS

Sedentary (sitting) behaviours are ubiquitous in modern society. We conducted a systematic review and meta-analysis to examine the association of sedentary time with diabetes, cardiovascular disease and cardiovascular and all-cause mortality.

METHODS

Medline, Embase and the Cochrane Library databases were searched for terms related to sedentary time and health outcomes. Cross-sectional and prospective studies were included. RR/HR and 95% CIs were extracted by two independent reviewers. Data were adjusted for baseline event rate and pooled using a random-effects model. Bayesian predictive effects and intervals were calculated to indicate the variance in outcomes that would be expected if new studies were conducted in the future.

RESULTS

Eighteen studies (16 prospective, two cross-sectional) were included, with 794,577 participants. Fifteen of these studies were moderate to high quality. The greatest sedentary time compared with the lowest was associated with a 112% increase in the RR of diabetes (RR 2.12; 95% credible interval [CrI] 1.61, 2.78), a 147% increase in the RR of cardiovascular events (RR 2.47; 95% CI 1.44, 4.24), a 90% increase in the risk of cardiovascular mortality (HR 1.90; 95% CrI 1.36, 2.66) and a 49% increase in the risk of all-cause mortality (HR 1.49; 95% CrI 1.14, 2.03). The predictive effects and intervals were only significant for diabetes.

CONCLUSIONS/INTERPRETATION

Sedentary time is associated with an increased risk of diabetes, cardiovascular disease and cardiovascular and all-cause mortality; the strength of the association is most consistent for diabetes.

Prolonged sedentary time and physical activity in workplace and non-work contexts: a cross-sectional study of office, customer service and call centre employees

BACKGROUND

To examine sedentary time, prolonged sedentary bouts and physical activity in Australian employees from different workplace settings, within work and non-work contexts.

METHODS

A convenience sample of 193 employees working in offices (131), call centres (36) and customer service (26) was recruited. Actigraph GT1M accelerometers were used to derive percentages of time spent sedentary (<100 counts per minute; cpm), in prolonged sedentary bouts (≥20 minutes or ≥30 minutes), light-intensity activity (100-1951 cpm) and moderate-to-vigorous physical activity (MVPA; ≥1952 cpm). Using mixed models adjusted for confounders, these were compared for: work days versus non-work days; work hours versus non-work hours (work days only); and, across workplace settings.

RESULTS

Working hours were mostly spent sedentary (77.0%, 95%CI: 76.3, 77.6), with approximately half of this time accumulated in prolonged bouts of 20 minutes or more. There were significant (p<0.05) differences in all outcomes between workdays and non-work days, and, on workdays, between work- versus non-work hours. Results consistently showed "work" was more sedentary and had less light-intensity activity, than "non-work". The period immediately after work appeared important for MVPA. There were significant (p<0.05) differences in all sedentary and activity outcomes occurring during work hours across the workplace settings. Call-centre workers were generally the most sedentary and least physically active at work; customer service workers were typically the least sedentary and the most active at work.

CONCLUSION

The workplace is a key setting for prolonged sedentary time, especially for some occupational groups, and the potential health risk burden attached requires investigation. Future workplace regulations and health promotion initiatives for sedentary occupations to reduce prolonged sitting time should be considered.

Sitting time and health outcomes among Mexican origin adults: obesity as a mediator

Background

Sitting time and sedentary behaviors have been associated with adverse health outcomes including obesity, diabetes and cardiovascular disease (CVD) within non- Hispanic White populations. Similar associations have not been described within Hispanic populations despite their high CVD risk profile. This study aimed to assess the association between sitting time and obesity, self-reported diagnosed diabetes, hypertension and high cholesterol among a large cohort (N=11,268) of Mexican origin adults and to assess whether obesity mediated these associations.

Methods

Using a cross-sectional design, data collected between 2004 and 2010 were analyzed in late 2010. Regression analyses evaluated associations between self-reported daily sitting hours and disease outcomes, controlling for demographics, employment status, family disease history, and light, moderate and strenuous physical activity.

Results

Participants were mostly female (81.1%) Mexican origin adults. Sitting time was associated with increased odds of being obese, having diabetes and having hypertension, but not high cholesterol. Adjusted odds ratios of participants who reported sitting > 4 hours/day compared to those sitting 1-2 hours/day were for obesity OR=1.55 (95% CI 1.39, 1.73), p<.001, for diabetes OR=1.29 (95% CI, 1.09, 1.52), p=.003, for hypertension OR=1.17 (95% CI, 1.01, 1.37), p=.041. Associations controlled for physical activity and employment status. Effects on hypertension and diabetes were mediated by obesity.

Conclusions

Sitting time was significantly associated with detrimental health outcomes, independent of physical activity. Obesity mediated these relationships for diabetes and hypertension. Future research should assess whether interventions addressing sitting time are feasible and effective among Mexican origin populations.