Occupational sitting and health risks: a systematic review

Let's Move Together

BACKGROUND

Due to shared health behaviors and disease risk, families may be more effective targets for health promotion. This study assessed whether providing family health history (FHH)-based risk information for heart disease and diabetes affected encouragement to engage in physical activity (PA) and healthy weight (HW) maintenance and co-engagement in physical activity among 320 Mexican-origin parents and their 1,081 children.

METHOD

At baseline and 10 months, parents indicated who they encouraged and who encouraged them to engage in PA/HW, and with whom they co-engaged in PA. Households were randomized to receive FHH-based assessments either by one or all adult household members. Primary analyses consisted of regression analyses using generalized estimating equations.

RESULTS

At baseline, parents reported encouraging their child for both PA and HW in 37.6% of parent-child dyads and reported receiving children's encouragement for both in 12.1% of dyads. These increased to 56.8% and 17.5% at 10 months ( p < .001). Co-engagement in PA increased from 11.4% to 15.7% ( p < .001), with younger children (30.4%) and mother-daughter dyads (26.8%) most likely to co-engage at 10 months. Providing FHH-based risk information to all adult household members (vs. one) was associated with increased parent-to-child encouragement of PA/HW ( p = .011) at 10 months but not child-to-parent encouragement. New encouragement from parent-to-child ( p = .048) and from child-to-parent ( p = .003) predicted new 10-month PA co-engagement.

DISCUSSION

Providing FHH information on a household level can promote parental encouragement for PA/HW, which can promote greater parent-child co-engagement in PA. In this high-risk population with a cultural emphasis on family ties, using FHH-based risk information for all adult household members may be a promising avenue to promote PA.

Effectiveness of Workplace Weight Management Interventions: a Systematic Review

A systematic review was conducted of randomized trials of workplace weight management interventions, including trials with dietary, physical activity, environmental, behavioral, and incentive-based components. Main outcomes were defined as change in weight-related measures. Keywords related to weight management and workplace interventions were used to search relevant databases, and 23 eligible studies were reviewed in detail using a data extraction form and quality assessment checklist. The trials were conducted mainly in the USA and Europe, with four additional countries represented. Interventions were mostly multicomponent and were implemented in both sexes and in a range of employment categories. Intervention effectiveness appeared unrelated to region of the world and was highest in 6-12-month trials. The results ranged widely from clinically significant 8.8-kg weight loss in one trial to less effective than the control treatment in others. Some workplace interventions achieve clinically significant benefits, and further studies are needed to replicate those results in wider sociocultural and geographical contexts.

The Effectiveness of a Web-Based Computer-Tailored Intervention on Workplace Sitting: A Randomized Controlled Trial

Background

Effective interventions to influence workplace sitting are needed, as office-based workers demonstrate high levels of continued sitting, and sitting too much is associated with adverse health effects. Therefore, we developed a theory-driven, Web-based, interactive, computer-tailored intervention aimed at reducing and interrupting sitting at work.

Objective

The objective of our study was to investigate the effects of this intervention on objectively measured sitting time, standing time, and breaks from sitting, as well as self-reported context-specific sitting among Flemish employees in a field-based approach.

Methods

Employees (n=213) participated in a 3-group randomized controlled trial that assessed outcomes at baseline, 1-month follow-up, and 3-month follow-up through self-reports. A subsample (n=122) were willing to wear an activity monitor (activPAL) from Monday to Friday. The tailored group received an automated Web-based, computer-tailored intervention including personalized feedback and tips on how to reduce or interrupt workplace sitting. The generic group received an automated Web-based generic advice with tips. The control group was a wait-list control condition, initially receiving no intervention. Intervention effects were tested with repeated-measures multivariate analysis of variance.

Results

The tailored intervention was successful in decreasing self-reported total workday sitting (time × group: P<.001), sitting at work (time × group: P<.001), and leisure time sitting (time × group: P=.03), and in increasing objectively measured breaks at work (time × group: P=.07); this was not the case in the other conditions. The changes in self-reported total nonworkday sitting, sitting during transport, television viewing, and personal computer use, objectively measured total sitting time, and sitting and standing time at work did not differ between conditions.

Conclusions

Our results point out the significance of computer tailoring for sedentary behavior and its potential use in public health promotion, as the effects of the tailored condition were superior to the generic and control conditions.

Trial Registration

Clinicaltrials.gov NCT02672215; http://clinicaltrials.gov/ct2/show/NCT02672215 (Archived by WebCite at http://www.webcitation.org/6glPFBLWv)

Perspectives on a 'Sit Less, Move More' Intervention in Australian Emergency Call Centres

Background

Prolonged sitting is associated with increased risk of chronic diseases. Workplace programs that aim to reduce sitting time (sit less) and increase physical activity (move more) have targeted desk-based workers in corporate and university settings with promising results. However, little is known about ‘move more, sit less’ programs for workers in other types of jobs and industries, such as shift workers. This formative research examines the perceptions of a ‘sit less, move more’ program in an Australian Emergency Call Centre that operates 24 hours per day, 7 days per week.

Methods

Participants were employees (N = 39, 72% female, 50% aged 36–55 years) recruited from Emergency Services control centres located in New South Wales, Australia. The ‘sit less, move more’ intervention, consisting of emails, posters and timer lights, was co-designed with the management team and tailored to the control centre environment and work practices, which already included electronic height-adjustable sit-stand workstations for all call centre staff. Participants reported their perceptions and experiences of the intervention in a self-report online questionnaire, and directly to the research team during regular site visits. Questionnaire topics included barriers and facilitators to standing while working, mental wellbeing, effects on work performance, and workplace satisfaction. Field notes and open-ended response data were analysed in an iterative process during and after data collection to identify the main themes.

Results

Whilst participants already had sit-stand workstations, use of the desks in the standing position varied and sometimes were contrary to expectations (e.g, less tired standing than sitting; standing when experiencing high call stress). Participants emphasised the “challenging” and “unrelenting” nature of their work. They reported sleep issues (“always tired”), work stress (“non-stop demands”), and feeling mentally and physically drained due to shift work and length of shifts. Overall, participants liked the initiative but acknowledged that their predominantly sitting habits were entrenched and work demands took precedence.

Conclusions

This study demonstrates the low acceptability of a ‘sit less, move more’ program in shift workers in high stress environments like emergency call centres. Work demands take priority and other health concerns, like poor sleep and high stress, may be more salient than the need to sit less and move more during work shifts.

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.

Underweight but metabolically abnormal phenotype: Metabolic features and its association with cardiovascular disease

BACKGROUND

Previous studies revealed that among people with normal and high body mass index (BMI), metabolic abnormalities contribute to the increased risk of cardiovascular disease (CVD). However, studies investigating the metabolic features and its association with CVD are limited.

METHODS

A national representative sample of adult population in China was used. Underweight was defined as BMI <18.5kg/m(2). Participants who had less than 2 criteria of metabolic syndrome were classified as metabolically healthy; those who had 2 or more criteria of metabolic syndrome were classified as metabolically abnormal. Presence of CVD and albuminuria were compared among groups stratified by BMI and metabolic status.

RESULTS

Among 46308 participants, 2267 (4.6%) were classified as underweight; and 372 (16.4%) of them were identified as metabolically abnormal. Metabolic features were comparable between underweight but metabolically abnormal participants and obese participants. Compared with participants with normal weight and normal metabolic features, the underweight but metabolically abnormal participants were more likely to have CVD and albuminuria, with an adjusted odds ratio of 2.33 (95% confidence interval (CI) 1.34-4.05) and 2.56 (95% CI 1.86-3.52), respectively. Among underweight participants, factors associated with metabolic abnormal phenotype included leisure time physical inactivity, mild occupational physical activity, and waist circumference.

CONCLUSIONS

Metabolically abnormal phenotype is not rare among underweight population in China, and preventive strategy against CVD should also be considered in that population.

Workplace interventions for reducing sitting at work

BACKGROUND

Office work has changed considerably over the previous couple of decades and has become sedentary in nature. Physical inactivity at workplaces and particularly increased sitting has been linked to increase in cardiovascular disease, obesity and overall mortality.

OBJECTIVES

To evaluate the effects of workplace interventions to reduce sitting at work compared to no intervention or alternative interventions.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, OSH UPDATE, PsycINFO, Clinical trials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal up to 2 June, 2015. We also screened reference lists of articles and contacted authors to find more studies to include.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-randomised controlled trials (cRCTs), and quasi-randomised controlled trials of interventions to reduce sitting at work. For changes of workplace arrangements, we also included controlled before-and-after studies (CBAs) with a concurrent control group. The primary outcome was time spent sitting at work per day, either self-reported or objectively measured by means of an accelerometer-inclinometer. We considered energy expenditure, duration and number of sitting episodes lasting 30 minutes or more, work productivity and adverse events as secondary outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full-text articles for study eligibility. Two review authors independently extracted data and assessed risk of bias. We contacted authors for additional data where required.

MAIN RESULTS

We included 20 studies, two cross-over RCTs, 11 RCTs, three cRCTs and four CBAs, with a total of 2180 participants from high income nations. The studies evaluated physical workplace changes (nine studies), policy changes (two studies), information and counselling (seven studies) and interventions from multiple categories (two studies). One study had both physical workplace changes and information and counselling components. We did not find any studies that had investigated the effect of periodic breaks or standing or walking meetings. Physical workplace changesA sit-stand desk alone compared to no intervention reduced sitting time at work per workday with between thirty minutes to two hours at short term (up to three months) follow-up (six studies, 218 participants, very low quality evidence). In two studies, sit-stand desks with additional counselling reduced sitting time at work in the same range at short-term follow-up (61 participants, very low quality evidence). One study found a reduction at six months' follow-up of -56 minutes (95% CI -101 to -12, very low quality evidence) compared to no intervention. Also total sitting time at work and outside work decreased with sit-stand desks compared to no intervention (MD -78 minutes, 95% CI -125 to -31, one study) as did the duration of sitting episodes lasting 30 minutes or more (MD -52 minutes, 95% CI -79 to -26, two studies). This is considerably less than the two to four hours recommended by experts. Sit-stand desks did not have a considerable effect on work performance, musculoskeletal symptoms or sick leave. It remains unclear if standing can repair the harms of sitting because there is hardly any extra energy expenditure.The effects of active workstations were inconsistent. Treadmill desks combined with counselling reduced sitting time at work (MD -29 minutes, 95% CI -55 to -2, one study) compared to no intervention at 12 weeks' follow-up. Pedalling workstations combined with information did not reduce inactive sitting at work considerably (MD -12 minutes, 95% CI -24 to 1, one study) compared to information alone at 16 weeks' follow-up. The quality of evidence was low for active workstations. Policy changesTwo studies with 443 participants provided low quality evidence that walking strategies did not have a considerable effect on workplace sitting time at 10 weeks' (MD -16 minutes, 95% CI -54 to 23) or 21 weeks' (MD -17 minutes, 95% CI -58 to 25) follow-up respectively. Information and counsellingCounselling reduced sitting time at work (MD -28 minutes, 95% CI -52 to -5, two studies, low quality evidence) at medium term (three months to 12 months) follow-up. Mindfulness training did not considerably reduce workplace sitting time (MD -2 minutes, 95% CI -22 to 18) at six months' follow-up and at 12 months' follow-up (MD -16 minutes, 95% CI -45 to 12, one study, low quality evidence). There was no considerable increase in work engagement with counselling.There was an inconsistent effect of computer prompting on sitting time at work. One study found no considerable effect on sitting at work (MD -17 minutes, 95% CI -48 to 14, low quality evidence) at 10 days' follow-up, while another study reported a significant reduction in sitting at work (MD -55 minutes, 95% CI -96 to -14, low quality evidence) at 13 weeks' follow-up. Computer prompts to stand reduced sitting at work by 14 minutes more (95% CI 10 to 19, one study) compared to computer prompts to step at six days' follow-up. Computer prompts did not change the number of sitting episodes that last 30 minutes or longer. Interventions from multiple categories Interventions combining multiple categories had an inconsistent effect on sitting time at work, with a reduction in sitting time at 12 weeks' (25 participants, very low quality evidence) and six months' (294 participants, low quality evidence) follow-up in two studies but no considerable effect at 12 months' follow-up in one study (MD -47.98, 95% CI -103 to 7, 294 participants, low quality evidence).

AUTHORS' CONCLUSIONS

At present there is very low to low quality evidence that sit-stand desks may decrease workplace sitting between thirty minutes to two hours per day without having adverse effects at the short or medium term. There is no evidence on the effects in the long term. There were no considerable or inconsistent effects of other interventions such as changing work organisation or information and counselling. There is a need for cluster-randomised trials with a sufficient sample size and long term follow-up to determine the effectiveness of different types of interventions to reduce objectively measured sitting time at work.

Objectively Measured Total and Occupational Sedentary Time in Three Work Settings

Background

Sedentary behaviour increases the risk for morbidity. Our primary aim is to determine the proportion and factors associated with objectively measured total and occupational sedentary time in three work settings. Secondary aim is to study the proportion of physical activity and prolonged sedentary bouts.

Methods

Data were obtained using ActiGraph accelerometers from employees of: 1) a financial service provider (n = 49 men, 31 women), 2) two research institutes (n = 30 men, 57 women), and 3) a construction company (n = 38 men). Total (over the whole day) and occupational sedentary time, physical activity and prolonged sedentary bouts (lasting ≥30 minutes) were calculated by work setting. Linear regression analyses were performed to examine general, health and work-related factors associated with sedentary time.

Results

The employees of the financial service provider and the research institutes spent 76–80% of their occupational time in sedentary behaviour, 18–20% in light intensity physical activity and 3–5% in moderate-to-vigorous intensity physical activity. Occupational time in prolonged sedentary bouts was 27–30%. Total time was less sedentary (64–70%), and had more light intensity physical activity (26–33%). The employees of the construction company spent 44% of their occupational time in sedentary behaviour, 49% in light, and 7% in moderate intensity physical activity, and spent 7% in sedentary bouts. Total time spent in sedentary behavior was 56%, 40% in light, and 4% in moderate intensity physical behaviour, and 12% in sedentary bouts. For women, low to intermediate education was the only factor that was negatively associated with occupational sedentary time.

Conclusions

Sedentary behaviour is high among white-collar employees, especially in highly educated women. A relatively small proportion of sedentary time was accrued in sedentary bouts. It is recommended that worksite health promotion efforts should focus on reducing sedentary behaviour through improving light intensity physical activity.

European Sitting Championship: Prevalence and Correlates of Self-Reported Sitting Time in the 28 European Union Member States

Objective

Sedentary behaviour is increasingly recognized as an important health risk, but comparable data across Europe are scarce. The objective of this study was to explore the prevalence and correlates of self-reported sitting time in adults across and within the 28 European Union Member States.

Methods

This study reports data from the Special Eurobarometer 412. In 2013, 27,919 randomly selected Europeans (approximately 1000 per Member State) were interviewed face-to-face. Sitting time on a usual day was self-reported and dichotomised into sitting less- and more than 7.5 hours per day. Uni- and multivariate odds ratios of sitting more than 7.5 hours per day were assessed by country and socio-demographic variables using binary logistic regression analyses. The analyses were stratified by country to study the socio-demographic correlates of sitting time within the different countries.

Results

A total of 26,617 respondents were included in the analyses. Median sitting time was five hours per day. Across Europe, 18.5 percent of the respondents reported to sit more than 7.5 hours per day, with substantial variation between countries (ranging from 8.9 to 32.1 percent). In general, northern European countries reported more sitting than countries in the south of Europe. ‘Current occupation’ and ‘age when stopped education’ were found to be the strongest correlates of sitting time, both across Europe and within most Member States. Compared to manual workers, the odds ratio of sitting more than 7.5 hours per day was 5.00 for people with white collar occupations, 3.84 for students, and 3.65 for managers.

Conclusions

There is substantial variation in self-reported sitting time among European adults across countries as well as socio-demographic groups. While regular surveillance of (objectively measured) sedentary behaviour is needed, the results of this study provide entry points for developing targeted interventions aimed at highly sedentary populations, such as people with sedentary occupations.

Comparison of the postural and physiological effects of two dynamic workstations to conventional sitting and standing workstations

Increasing evidence is being found for the association of health risk factors with work-related physical inactivity. An increasing number of people are being exposed to this form of inactivity, and as a result, various interventions aimed at increasing physical activity during working hours are being developed. This study aims to investigate the differences in postural, muscular and physical activities resulting from two dynamic workstations, namely an elliptical trainer and a treadmill workstation, compared with a conventional sitting and standing workstation. Twelve participants completed five standardised office tasks in a laboratory setting at all workstations. No significant effect was found regarding changes in posture and the muscular activity was only significantly higher for the trapezius muscle (50th percentile: 8.1 %MVC) at the dynamic workstations. For the dynamic workstations, physical activity ranged from 4.0 to 14.9 × 10(-2) g, heart rate from 14.3 to 27.5 %HRR and energy expenditure from 1.8 to 3.1 METs. Practitioner Summary: Work-related physical inactivity is associated with health risk factors. In this study, physiological and postural effects of dynamic workstations were assessed in comparison to conventional workstations. No significant effects were found regarding changes in posture and muscular activity. Physical activity, heart rate and energy expenditure increased for the dynamic workstations.

Sedentary behavior and subclinical atherosclerosis in African Americans: cross-sectional analysis of the Jackson heart study

Background

Previous studies have reported conflicting results as to whether an association exists between sedentary time and cardiovascular disease (CVD) risk among African Americans. These studies, however, were limited by lack of consideration of sedentary behavior in leisure versus non-leisure settings. To elucidate this relation, we investigated the associations of television (TV) viewing time and occupational sitting with carotid intima-media thickness (CIMT), a subclinical atherosclerosis measure, in a community-based sample of African Americans.

Methods

We studied 3410 participants from the Jackson Heart Study, a single-site, community-based study of African Americans residing in Jackson, MS. CIMT was assessed by ultrasonography and represented mean far-wall thickness across right and left sides of the common carotid artery. TV viewing time, a measure of leisure sedentary behavior, and occupational sitting, a measure of non-leisure sedentary behavior, were assessed by questionnaire.

Results

In a multivariable regression model that included physical activity and CVD risk factors, longer TV viewing time (2–4 h/day and >4 h/day) was associated with greater CIMT (adjusted mean ± SE difference from referent [<2 h/day] of 0.009 ± 0.008 mm for 2–4 h/day, and 0.028 ± 0.009 mm for >4 h/day; P-trend =0.001). In contrast, more frequent occupational sitting (‘sometimes’ and ‘often/always’) was associated with lower CIMT (adjusted mean ± SE difference from referent [‘never/seldom’]:−0.021 ± 0.009 mm for ‘sometimes’, and−0.018 ± 0.008 mm for ‘often/always’; P-trend = 0.042).

Conclusions

Longer TV viewing time was associated with greater CIMT, while occupational sitting was associated with lower CIMT. These findings suggest the role of sedentary behaviors in the pathogenesis of CVD among African Americans may vary by whether individuals engage in leisure versus non-leisure sedentary behaviors.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-016-0349-y) contains supplementary material, which is available to authorized users.

Percentage-Method Improves Properties of Workers' Sitting- and Walking-Time Questionnaire

Background

Does asking for the percentage of time spent sitting during work (P-method) instead of asking for the absolute length of time spent sitting (T-method) improve properties of the workers’ sitting- and walking-time questionnaire (WSWQ)? The purpose of this study was to investigate whether questioning technique influences test-retest reliability and criterion validity of the WSWQ.

Methods

Sixty-five Japanese workers completed each version of the WSWQ in random order. Both questionnaires assessed quantities of time spent sitting or walking (including standing) during work time, non-working time on a workday, and anytime on a non-workday. Participants wore the thigh-worn inclinometer (activPAL) as criterion measure. Intraclass correlation coefficients (ICC) and Spearman’s ρ were used for the analyses.

Results

For all three domains, values of reliability and validity with the P-method tended to be higher than with the T-method: ICC values ranged from 0.48–0.85 for the T-method and from 0.71–0.85 for the P-method; Spearman’s ρ values ranged from 0.25–0.58 for the T-method and from 0.42–0.65 for the P-method. The validities with both methods on a workday (0.51–0.58 for the T-method and 0.56–0.65 for the P-method) were higher than validities on a non-workday (0.25–0.45 for the T-method and 0.42–0.60 for the P-method). In post-survey interviews, 48 participants (77%) chose the P-method as their preferred questioning style.

Conclusions

The study revealed that the P-method WSWQ had better reliability, validity, and ease of answering than the T-method, suggesting that the P-method can improve properties of the WSWQ and consequently advance the quality of epidemiological surveys in this field.

Sitting Time, Fidgeting, and All-Cause Mortality in the UK Women's Cohort Study

INTRODUCTION

Sedentary behaviors (including sitting) may increase mortality risk independently of physical activity level. Little is known about how fidgeting behaviors might modify the association.

METHODS

Data were from the United Kingdom (UK) Women's Cohort Study. In 1999-2002, a total of 12,778 women (aged 37-78 years) provided data on average daily sitting time, overall fidgeting (irrespective of posture), and a range of relevant covariates including physical activity, diet, smoking status, and alcohol consumption. Participants were followed for mortality over a mean of 12 years. Proportional hazards Cox regression models estimated the relative risk of mortality in high (versus low) and medium (versus low) sitting time groups.

RESULTS

Fidgeting modified the risk associated with sitting time (p=0.04 for interaction), leading us to separate groups for analysis. Adjusting for covariates, sitting for ≥7 hours/day (versus <5 hours/day) was associated with 30% increased all-cause mortality risk (hazard ratio [HR]=1.30, 95% CI=1.02, 1.66) only among women in the low fidgeting group. Among women in the high fidgeting group, sitting for 5-6 hours/day (versus <5 hours/day) was associated with decreased mortality risk (HR=0.63, 95% CI=0.43, 0.91), adjusting for a range of covariates. There was no increased mortality risk from longer sitting time in the middle and high fidgeting groups.

CONCLUSIONS

Fidgeting may reduce the risk of all-cause mortality associated with excessive sitting time. More detailed and better-validated measures of fidgeting should be identified in other studies to replicate these findings and identity mechanisms, particularly measures that distinguish fidgeting in a seated from standing posture.

The Relation between Occupational Sitting and Mental, Cardiometabolic, and Musculoskeletal Health over a Period of 15 Years--The Doetinchem Cohort Study

OBJECTIVE

Sedentary behaviors are reported to impose health risks. Since occupational exposure is a major proportion of total sedentary time, we studied the association between occupational sitting and a number of health problems.

METHODS

From the longitudinal Doetinchem Cohort Study, we selected those working at baseline with complete data (n = 1,509). Participants were examined four times at 5 year-intervals between 1993 and 2012. We characterized occupational sitting as follows: 1) stable sitters and stable non sitters over a 15-year period, based on job characteristics and (2) having a job with a low, moderate or high amount of sitting, based on tertiles of self-reported number of hours per week of occupational sitting, measured at wave 5. Linear and logistic regression models were used. Outcomes were self-reported mental health, low-back or upper extremity pain, and objectively measured cardiometabolic health (overweight, hypertension, hypercholesterolemia).

RESULTS

Compared to stable non sitters, a lower risk of chronic upper extremity pain was observed for stable sitters (OR 0.75, 95% CI: 0.57; 1.00) as well as for those in the two upper tertiles for hours of occupational sitting (>4 hr/wk) (OR 0.65; 95%CI 0.50-0.86). For the other health outcomes studied, no significant associations were found with occupational sitting.

CONCLUSION

Our findings do not support the hypothesis that occupational sitting is associated with health problems. The finding that occupational sitting is associated with less upper extremity pain might be due to the association of occupational sitting with less physical load.

Sedentary behaviors and light-intensity activities in relation to colorectal cancer risk

A recent meta-analysis found that sedentary behaviors are associated with an increased colorectal cancer (CRC) risk. Yet, the finding on TV viewing time, the most widely used surrogate of sedentary behaviors, was based on only two studies. Furthermore, light-intensity activities (e.g., standing and slow walking), non-sedentary by posture but close to sedentary behaviors by Metabolic Equivalent Task values, have not been investigated in relation to CRC risk. Thus, we prospectively analyzed the relationships based on 69,715 women from Nurses' Health Study (1992-2010) and 36,806 men from Health Professionals Follow-Up Study (1988 - 2010). Throughout follow-up, time spent on sedentary behaviors including sitting watching TV and on light-intensity activities were assessed repeatedly; incidence of CRC was ascertained. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models from each cohort. A total of 1,119 and 913 incident cases were documented from women and men, respectively. The multivariable HR comparing ≥ 21 versus < 7 hr/week of sitting watching TV was 1.21 (95% CI = 1.02 to 1.43, ptrend =.01) in women and 1.06 (95% CI = 0.84 to 1.34, ptrend =.93) in men. In women, those highly sedentary and physically less active had an approximately 41% elevated risk of CRC (95% CI = 1.03 to 1.92) compared with those less sedentary and physically more active. The other sedentary behaviors and light-intensity activities were not related to CRC risk in women or men. In conclusion, we found that prolonged sitting time watching TV was associated with an increased CRC risk in women but not in men.

Quantifying Socioeconomic and Lifestyle Related Health Risks: Burden of Cardiovascular Disease Among Indian Males

Background

Non-communicable diseases account for a significant disease burden in the South East Asia region. India is facing an increased incidence of lifestyle-related diseases, such as cardiovascular disease. Socioeconomic and lifestyle risk factors for cardiovascular disease (CVD) have been under investigated in India. This study was designed to explore risk factors contributing to the development of cardiovascular disease among Indian males.

Methods

A population-based cross-sectional study was conducted among 2,235 males in the age group of 18-60 years across three states of India. A household survey was used to collect demographic and socioeconomic status information in addition to lifestyle-related attributes such as smoking, alcohol consumption, diet, and physical activity. Descriptive statistics and logistic regression were performed to identify the role of various factors that may be associated with the development of cardiovascular disease in this population.

Results

The prevalence of cardiovascular disease among the male respondents contacted through a household survey was reported to be 9.8%. Logistic regression revealed that males with higher education and higher income were more likely to report CVD. With age as a strong predictor of CVD, the risk of CVD was found to be five times higher in the older age group. Current smokers were 1.3 times more likely to have CVD compared to those who never smoked. Those who were engaged in physical activity were less likely to have CVD; however, the adverse effects of smoking and excessive consumption of red meat showed a stronger association with CVD than the protective effects of physical activity.

Conclusion

In developing countries, where the increase in earning capacity and change in lifestyle has been found to be accompanied by substantial risk of heart disease for males, public health measures like health promotion programs need to be implemented to decrease CVD burden.

Occupation and risk of sudden death in a United States community: a case-control analysis

OBJECTIVE

Work environment is said to influence cardiovascular risk. We assessed whether nature of occupation affects risk of sudden cardiac death (SCD) in the general population.

METHODS

In the ongoing, prospective Oregon Sudden Unexpected Death Study (catchment population 1 million), working-age SCD cases (18-65 years) were compared with controls who died from any cause. Usual occupation obtained from death certificates was classified using the US Census Bureau standard occupational classification descriptions and categorised as white collar, blue collar or homemaker. Odds ratio (OR) for SCD by occupation category was obtained and clinical profile of SCD cases was compared by occupation type.

RESULTS

Among SCD cases (n=646; 74% male) compared to controls (n=622; 73.6% male), the proportion of white collar workers was higher among male SCD cases (52.7% vs 43.7%; p=0.01); the difference in females was smaller (59.5% vs 55%; p=0.62). Adjusting for race and smoking status, male white collar workers had a higher risk of SCD compared to blue collar workers (OR=1.67, (1.26 to 2.23), p<0.001). A similar, non-significant trend was observed among females (OR 1.49 (0.81 to 2.75); p=0.20). White collar SCD cases were less likely to be current smokers (34.7% vs 45.3%, p=0.008), drug misusers (13.1% vs 18.5%) or have diabetes (21.4% vs 28.2%, both p=0.07) compared to blue collar workers. Other cardiac risk factors were similar.

CONCLUSIONS

A white collar occupation was associated with increased risk of SCD, when compared to blue collar occupations. Since differences in conventional risk factors did not explain this elevated risk, work-related behavioural and psychosocial stressors warrant a closer evaluation.

More standing and just as productive: Effects of a sit-stand desk intervention on call center workers' sitting, standing, and productivity at work in the Opt to Stand pilot study

This study evaluated the effects of sit-stand desks on workers' objectively and subjectively assessed sitting, physical activity, and productivity. This quasi-experimental study involved one intervention group (n = 16) and one comparison group (n = 15). Participants were call center employees from two job-matched teams at a large telecommunications company in Sydney, Australia (45% female, 33 ± 11 years old). Intervention participants received a sit-stand desk, brief training, and daily e-mail reminders to stand up more frequently for the first 2 weeks post-installation. Control participants carried out their usual work duties at seated desks. Primary outcomes were workday sitting and physical activity assessed using ActivPAL or ActiGraph devices and self-report questionnaires. Productivity outcomes were company-specific objective metrics (e.g., hold time, talking time, absenteeism) and subjective measures. Measurements were taken at baseline, 1, 4, and 19 weeks post-installation. Intervention participants increased standing time after 1 week (+ 73 min/workday (95% CI: 22, 123)) and 4 weeks (+ 96 min/workday (95% CI: 41, 150)) post-intervention, while control group showed no changes. Between-group differences in standing time at one and 4 weeks were + 78 (95% CI: 9, 147) and + 95 min/workday (95% CI: 15, 174), respectively. Sitting time in the intervention group changed by − 64 (95% CI: − 125, − 2), − 76 (95% CI: − 142, − 11), and − 100 min/workday (95% CI: − 172, − 29) at 1, 4, and 19 weeks post-installation, respectively, while the control group showed no changes. No changes were observed in productivity outcomes from baseline to follow-up in either group. Sit-stand desks can increase standing time at work in call center workers without reducing productivity.

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Few workplace sitting interventions have involved objective productivity outcomes.

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This sit-stand desk intervention increased standing time in call center workers (73–90 min/workday).

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Sitting time decreased in the intervention group (64–100 min/workday).

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Using sit-stand desks at work did not change call center workers’ productivity (e.g., talking time, hold time).

Association Between Television Viewing Time and All-Cause Mortality: A Meta-Analysis of Cohort Studies

Findings on the association between television (TV) viewing and all-cause mortality in epidemiologic studies have been inconsistent. Therefore, we conducted a meta-analysis of data from prospective cohort studies to quantify this association. Relevant articles were identified by searching MEDLINE (PubMed; National Library of Medicine, Bethesda, Maryland) and EMBASE (Elsevier B.V., Amsterdam, the Netherlands) from inception to March 1, 2015, and reviewing the reference lists of retrieved articles. Study-specific results were pooled using a random-effects model. Of 2,578 citations identified by the search strategy, 10 cohort studies (61,494 deaths among 647,475 individuals) met the inclusion criteria. The summary relative risk of all-cause mortality for the highest category of TV viewing time versus the lowest was 1.33 (95% confidence interval: 1.20, 1.47), with heterogeneity among studies (I(2) = 66.7%, P(heterogeneity) = 0.001). In dose-response meta-analysis, TV viewing time was statistically significantly associated with all-cause mortality risk in a J-shaped fashion (P(nonlinearity) = 0.001). These results indicate that prolonged TV viewing time might increase the risk of all-cause mortality. Given the high prevalence of excessive TV viewing, public health recommendations or interventions aimed at decreasing the amount of TV viewing time in modern societies are warranted.

Association Between Sedentary Work and BMI in a U.S. National Longitudinal Survey

INTRODUCTION

Technological advancements have made life and work more sedentary, and long hours of sitting are known to be associated with many health concerns. Several studies have reported an association between prolonged sitting time at work and weight gain, but the results are inconsistent. This study examined the relationship between sitting time at work and BMI using data from a large prospective cohort of U.S. men and women from 2002 to 2010. Initial analyses were performed in 2013, with additional analyses in 2014 and 2015.

METHODS

The sample size at the base year (2002) was 5,285 and the age range 38-45 years. The outcome, BMI, was based on self-reported measures of height and weight. Estimates of workplace sitting time were linked from an external database (Occupational Information Network), and the occupation-wide rating for sitting time was linked to survey participants by occupation. Fixed-effects models controlling for time-invariant effects of all time-invariant characteristics were employed to examine the association, controlling for age, education, work hours, and hours of vigorous and light/moderate physical activities.

RESULTS

Longer sitting time was significantly associated with higher BMI for the overall sample (β = 0.054; p<0.05) and men (β = 0.086; p<0.01). For women, the association was not statistically significant.

CONCLUSIONS

The findings provide further support for initiatives to reduce workplace sitting time as a means of reducing the risk of weight gain and related health conditions.

Associations of sitting behaviours with all-cause mortality over a 16-year follow-up: the Whitehall II study

BACKGROUND

Sitting behaviours have been linked with increased risk of all-cause mortality independent of moderate to vigorous physical activity (MVPA). Previous studies have tended to examine single indicators of sitting or all sitting behaviours combined. This study aims to enhance the evidence base by examining the type-specific prospective associations of four different sitting behaviours as well as total sitting with the risk of all-cause mortality.

METHODS

Participants (3720 men and 1412 women) from the Whitehall II cohort study who were free from cardiovascular disease provided information on weekly sitting time (at work, during leisure time, while watching TV, during leisure time excluding TV, and at work and during leisure time combined) and covariates in 1997-99. Cox proportional hazards models were used to investigate prospective associations between sitting time (h/week) and mortality risk. Follow-up was from date of measurement until (the earliest of) death, date of censor or July 31 2014.

RESULTS

Over 81 373 person-years of follow-up (mean follow-up time 15.7 ± 2.2 years) a total of 450 deaths were recorded. No associations were observed between any of the five sitting indicators and mortality risk, either in unadjusted models or models adjusted for covariates including MVPA.

CONCLUSIONS

Sitting time was not associated with all-cause mortality risk. The results of this study suggest that policy makers and clinicians should be cautious about placing emphasis on sitting behaviour as a risk factor for mortality that is distinct from the effect of physical activity.

Validity and responsiveness of four measures of occupational sitting and standing

Background

Evidence on the detrimental health effects of prolonged sedentary behavior is accumulating. Interventions need to have a specific focus on sedentary behavior in order to generate clinically meaningful decreases in sedentary time. When evaluating such intervention, the question whether a participant improved or deteriorated their behavior is fundamental and instruments that are able to detect those changes are essential. Therefore, the aim of this study was to determine the criterion validity against activPAL and responsiveness to change of two activity monitors (ActiGraph and activPAL) and two questionnaires for the assessment of occupational sitting and standing time.

Methods

42 participants took part in the Stand@Work intervention trial. Six (T0) and two (T1) weeks before they received a sit-stand workstation and three weeks thereafter (T2), participants wore an ActiGraph and an activPAL activity monitor, and completed the Occupational Sitting and Physical Activity Questionnaire (OSPAQ) and the Workforce Sitting Questionnaire (WSQ). The activPAL was used as the criterion validity measure.

Results

The ActiGraph showed strong validity for occupational sedentary time at T0 and T1 (Spearman rho = 0.77 and 0.69), but its validity dropped substantially after introduction of the sit-stand workstation (rho = 0.19). Correlations between occupational light-intensity activity assessed by the ActiGraph and occupational standing time assessed by the activPAL varied between 0.25–0.63. The occupational sitting validity correlation of the OSPAQ and WSQ varied from 0.35-0.48 and 0.25-0.30, respectively, and between 0.16–0.68 for the OSPAQ for occupational standing time. The intervention-induced changes in occupational sitting and standing time were well detected by the activPAL, OSPAQ and WSQ (sitting only), but not by the ActiGraph, which had the lowest responsiveness to change.

Conclusions

This study suggests that studies aimed at determining differences in occupational sitting and standing time should use activPAL-type inclinometers as a preferred type of objective measure. Simple questionnaires showed sufficient validity and are usable in addition to an objective measure or alone when objective monitoring is not possible. The hip-worn ActiGraph was unable to distinguish between occupational sitting and standing time, when using uniaxial data and traditional cut-points for sedentary time and light-intensity activity.

Trial registration

The study was registered with the Australian New Zealand Clinical Trials Registry (No. ACTRN 12612000072819).

Deviation between self-reported and measured occupational physical activity levels in office employees: effects of age and body composition

OBJECTIVES

Whether occupational physical activity (PA) will be assessed via questionnaires or accelerometry depends on available resources. Although self-reported data collection seems feasible and inexpensive, obtained information could be biased by demographic determinants. Thus, we aimed at comparing self-reported and objectively measured occupational sitting, standing, and walking times adjusted for socio-demographic variables.

METHODS

Thirty-eight office employees (eight males, 30 females, age 40.8 ± 11.4 years, BMI 23.9 ± 4.2 kg/m(2)) supplied with height-adjustable working desks were asked to report sitting, standing, and walking times using the Occupational Sitting and Physical Activity Questionnaire during one working week. The ActiGraph wGT3X-BT was used to objectively measure occupational PA during the same week. Subjectively and objectively measured data were compared computing the intra-class correlation coefficients, paired t tests and Bland-Altman plots. Furthermore, repeated-measurement ANOVAs for measurement (subjective vs. objective) and socio-demographic variables were calculated.

RESULTS

Self-reported data yielded a significant underestimation of standing time (13.3 vs. 17.9%) and an overestimation of walking time (12.7 vs. 5.0%). Significant interaction effects of age and measurement of standing time (F = 6.0, p = .02, ηp(2) = .14) and BMI group and measurement of walking time were found (F = 3.7, p = .04, ηp(2) = .17). Older employees (>39 years) underestimated their standing time, while underweight workers (BMI < 20 kg/m(2)) overestimated their walking time.

CONCLUSIONS

Self-reported PA data differ from objective data. Demographic variables (age, BMI) affect the amount of self-reported misjudging of PA. In order to improve the validity of self-reported data, a correction formula for the economic assessment of PA by subjective measures is needed, considering age and BMI.

Alternating bouts of sitting and standing attenuate postprandial glucose responses

PURPOSE

This study aimed to examine whether reductions in sitting time through alternating 30-min bouts of sitting and standing can reduce postprandial glucose, insulin, and triglyceride responses.

METHODS

Twenty-three overweight/obese sedentary office workers (17 males and six females; mean ± SD: age, 48.2 ± 7.9 yr; body mass index, 29.6 ± 4.0 kg · m(-2)) undertook two short-term (5 d) experimental conditions in an equal, randomized (1:1) order. In a simulated office environment, participants performed typical occupational tasks for 8 h · d(-1) while in a 1) seated work posture (control condition) or 2) interchanging between a seated and standing work posture every 30 min using an electric, height-adjustable workstation (intervention condition). Fasting and postprandial blood samples after a mixed test drink were collected hourly for 4 h on days 1 and 5 of each condition to assess serum insulin, plasma glucose, and triglycerides. Dietary intake (kJ · d(-1)) and physical activity were standardized during each condition. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12611000632998).

RESULTS

After adjustment for time (days 1 and 5), incremental area under the analyte time curve differed significantly between conditions for plasma glucose (P = 0.007) but not for serum insulin or plasma triglycerides. Adjusted mean glucose incremental area under the analyte time curve was lowered by 11.1% after the intervention condition (6.38 mM · h(-1) (confidence interval, 5.04-7.71)) relative to the control condition (7.18 mM · h(-1) (confidence interval, 5.85-8.52)). No temporal changes (days 1 vs 5) between conditions were observed.

CONCLUSIONS

Alternating standing and sitting in 30-min bouts results in modest beneficial effects on postprandial glucose responses in overweight/obese office workers.

Validity of self-reported sedentary time differs between Australian rural men engaged in office and farming occupations

Rural Australians have a higher likelihood of chronic disease than urban Australians, particularly male farmers. Chronic disease has been associated with occupational sedentary time. The aim was to validate the self-report of sedentary time in men in contrasting rural occupations. Farmers (n = 29) and office workers (n = 28), age 30-65 years, were recruited from the Riverland region of South Australia. Daily sedentary time and number of breaks in sedentary time were self-reported and measured objectively using body-worn inclinometers. Correlational analyses were conducted between self-reported and objectively measured variables, separately by occupation. There was a significant correlation between self-reported and objectively measured sedentary time in the whole sample (r = 0.44, P = 0.001). The correlation among office workers was significant (r = 0.57, P = 0.003) but not among farmers (r = 0.08, P = 0.68). There were no significant correlations between self-reported and measured number of breaks in sedentary time, for the whole sample (rho = -0.03, P = 0.83), office workers (rho = 0.17, P = 0.39) and farmers (rho = -0.22, P = 0.25). In conclusion, the validity of self-report of sedentary behaviours by farmers was poor. Further research is needed to develop better performing self-report instruments or more accessible objective measures of sedentary behaviour in this population.

Differences between work and leisure in temporal patterns of objectively measured physical activity among blue-collar workers

Background

Leisure time physical activity (LTPA) is generally associated with favorable cardiovascular health outcomes, while occupational physical activity (OPA) shows less clear, or even opposite, cardiovascular effects. This apparent paradox is not sufficiently understood, but differences in temporal patterns of OPA and LTPA have been suggested as one explanation. Our aim was to investigate the extent to which work and leisure (non-occupational time) differ in temporal activity patterns among blue-collar workers, and to assess the modification of these patterns by age and gender.

Methods

This study was conducted on a cross-sectional sample of male (n = 108) and female (n = 83) blue-collar workers, aged between 21 and 65 years. Physical activity and sedentary behavior were assessed using accelerometers (Actigraph GT3X+) worn on the thigh and trunk for four consecutive days. Temporal patterns of OPA and LTPA were retrieved using Exposure Variation Analysis (EVA), and expressed in terms of percentage of work and leisure time spent in uninterrupted periods of different durations (<1 min, 1–5 min, 5–10 min, 10–30 min, 30–60 min and > 60 min) of sitting, standing, and walking. Repeated measures ANOVA and linear regression analyses were used to test a) possible differences between OPA and LTPA in selected EVA derivatives, and b) the modification of these differences by age and gender.

Results

OPA showed a larger percentage time walking in brief (<5 min) periods [mean (SD): 33.4 % (12.2)], and less time in prolonged (>30 min) sitting [7.0 % (9.3)] than LTPA [walking 15.4 % (5.0); sitting 31.9 % (15.3)], even after adjustment for the difference between work and leisure in total time spent in each activity type. These marked differences in the temporal pattern of OPA and LTPA were modified by gender, but not age.

Conclusion

We found that the temporal patterns of OPA and LTPA among blue-collar workers were markedly different even after adjustment for total physical activity time, and that this difference was modified by gender. We recommend using EVA derivatives in future studies striving to disentangle the apparent paradoxical cardiovascular effect of physical activity at work and during leisure.

Theory-driven, web-based, computer-tailored advice to reduce and interrupt sitting at work: development, feasibility and acceptability testing among employees

Background

Because of the adverse health effects in adults, interventions to influence workplace sitting, a large contributor to overall daily sedentary time, are needed. Computer-tailored interventions have demonstrated good outcomes in other health behaviours, though few have targeted sitting time at work. Therefore, the present aims were to (1) describe the development of a theory-driven, web-based, computer-tailored advice to influence sitting at work, (2) report on the feasibility of reaching employees, and (3) report on the acceptability of the advice.

Methods

Employees from a public city service (n = 179) were invited by e-mail to participate. Employees interested to request the advice (n = 112) were sent the website link, a personal login and password. The online advice was based on different aspects of the Theory of Planned Behaviour, Self-Determination Theory and Self-Regulation Theory. Logistic regressions were conducted to compare characteristics (gender, age, education, employment status, amount of sitting and psychosocial correlates of workplace sitting) of employees requesting the advice (n = 90, 80.4 %) with those who did not. Two weeks after visiting the website, 47 employees (52.2 %) completed an online acceptability questionnaire.

Results

Those with a high education were more likely to request the advice than those with a low education (OR = 2.4, CI = 1.0-5.8), and those with a part-time job were more likely to request the advice compared to full-time employees (OR = 2.9, CI = 1.2-7.1). The majority found the advice interesting (n = 36/47, 76.6 %), relevant (n = 33/47, 70.2 %) and motivating (n = 29/47, 61.7 %). Fewer employees believed the advice was practicable (n = 15/47, 31.9 %). After completing the advice, 58.0 % (n = 25/43) reported to have started interrupting their sitting and 32.6 % (n = 17/43) additionally intended to do so; 14.0 % (n = 6/43) reported to have reduced their sitting and another 51.2 % (n = 22/43) intended to do so.

Discussion

More efforts are needed to reach lower educated and full-time workers. Further research should examinethe effects of this intervention in a rigorous randomised controlled trial.

Conclusions

It is feasible to reach employees with this tool. Most of the employees who requested the advice found itacceptable and reported they changed their behaviour or intended to change it. Interrupting sittingappeared more achievable than reducing workplace sitting.

Why Women Sit: Determinants of Leisure Sitting Time for Working Women

BACKGROUND

Sedentary behavior is associated with negative health consequences independent of physical activity levels. Evidence suggests the work environment promotes sedentary behavior regardless of sector, and that employees with occupations requiring longer sitting times differ only marginally in leisure sitting time from those with more active occupations. Because physical activity opportunities may be limited across many work settings, leisure sedentary time may be more easily replaced with physical activity. Understanding correlates of leisure sedentary behaviors could inform interventions, specifically for women who are among the least active in America.

METHODS

Female employees at two universities completed online surveys (n = 156; mean age, 45.12 [SD = 12.5]; mean BMI, 26.7 kg/m(2) [SD = 5.9]; mean work hours/week, 43.7 [SD = 9.4]). Bivariate correlations and two hierarchical regression analyses were conducted to examine personal and behavioral correlates of weekday and weekend leisure sitting time.

FINDINGS

Final regression models revealed that greater weekday leisure sitting time (R(2) = 0.307) was related with being older (p = .006), having fewer children (p = .001), self-reporting poorer health (p = .006), and greater weekend sitting time (p < .001). Greater weekend leisure sitting time (R(2) = 0.261) was related with greater work-related sitting time (p = .020) and greater weekday leisure sitting time (p < .001). Physical activity was not related with weekday or weekend leisure sitting time.

CONCLUSIONS

The most prominent correlates of leisure sitting time were other types of sedentary behaviors. This suggests that sedentary time in one segment of life predicts time spent sitting in other areas of life. Future interventions should target decreasing sedentary behaviors during leisure time specifically, in addition to increasing physical activity behavior.

Pain and Prejudice: Does Collecting Information From the Standpoint of Exposed Workers Improve Scientific Examination of Work-Related Musculoskeletal Disorders?

The meaning, feasibility, and importance of scientific objectivity have been debated among public health scientists. The debate is particularly relevant to occupational health, because of frequent opposition between employer and worker interests. This article suggests that the concept of standpoint (J. Eakin) may be more useful than that of objectivity in framing discussion of work-related musculoskeletal disorders. Studies done from a "worker" standpoint can, for example, investigate and characterize environmental risk factors for work-related musculoskeletal disorders, while studies from an "employer" standpoint may concentrate on identifying individual workers likely to report work-related musculoskeletal disorders or those for whom consequences of work-related musculoskeletal disorders are more severe. Within "worker" standpoints, a distinction between "high-prestige worker" and "lower-prestige worker" standpoints can be identified in the current scientific debate about the health costs and benefits of prolonged standing vs prolonged sitting at work. Contact with workers, particularly lower-prestige workers, is critical to developing and sustaining a worker-based standpoint among researchers in occupational health. This contact can be facilitated by formal collaborations between universities and unions or other community groups.

Physical activity, sedentary behavior time and lipid levels in the Observation of Cardiovascular Risk Factors in Luxembourg study

Background

Recently attention has been drawn to the health impacts of time spent engaging in sedentary behaviors. While many studies have investigated general physical activity (PA) in relation to blood lipid levels, the current study aimed to examine the intensity of activity, including sedentary behavior time, and time spent engaging in moderate and intense PA, with concentrations of HDL and LDL-cholesterol, total cholesterol, and triglycerides.

Methods

Participants comprised 1331 individuals, aged 18 to 70 years, from the Observation of Cardiovascular Risk Factors in Luxembourg (ORISCAV-LUX) study, who underwent objective cardiovascular health assessments and completed the International Physical Activity Questionnaire (IPAQ). Time spent engaging in sedentary behaviors (screen time on a workday and a day off, and total sitting time on a work day), and moderate and intense PA, were related to levels of HDL and LDL-cholesterol, total cholesterol, and triglycerides. Analyses were conducted in the whole sample, and then with stratification according to BMI (normal weight versus overweight/obese).

Results

Both lower screen time during days off and higher intense PA time were significantly associated with higher HDL-cholesterol after full adjustment for socio-demographic factors, dietary factors and smoking (both p < 0.05). In normal weight individuals, consistent positive relations between triglycerides, LDL, and total cholesterol with all sedentary behavior time variables were observed (all p < 0.05; adjusted for age, education, gender). There were no statistically significant associations between any intensity level of PA or sedentary behavior time variable and lipid levels in those overweight or obese.

Conclusions

Spending less time in sedentary behaviors, and engaging in medium levels of intense physical activity may be associated with a more favorable blood lipid profile, particularly with regard to levels of HDL and triglycerides.

Is Sitting Too Much Bad for Your Health?

Office workers spend a large part of their workday sitting down. Too much sitting seems bad for people’s health and puts them at risk for premature death. Workstation alternatives that allow desk work to be done while standing, walking, biking, or stepping reduce the total time spent sitting without affecting work performance much. Moreover, these alternatives seem acceptable to users. Future research is needed to determine long-term effects and whether results apply to different working populations. Ergonomists play an important role in developing recommendations for the setup and use of alternative workstations and in improving their feasibility.

Improving current practice in reviews of the built environment and physical activity

Over the last decade, there has been a marked increase in studies about built environments and physical activity. As the number of publications is growing rapidly, literature reviews play an important role in identifying primary studies and in synthesizing their findings. However, many of the reviews of effectiveness in this field demonstrate methodological limitations that might lead to inaccurate portrayals of the evidence. Some literature reviews a priori excluded intervention studies even though they provide the strongest level of evidence. The label 'systematic review' has mostly been used inappropriately. One of the major criteria of a systematic review that is hardly ever met is that the quality of the primary studies needs to be assessed and this should be reflected in the synthesis, presentation and interpretation of results. With few exceptions, 'systematic' reviews about environments and physical activity did not refer to or follow the QUORUM or PRISMA statements. This commentary points out the usefulness of the PRISMA statement to standardize the reporting of methodology of reviews and provides additional guidance to limit sources of bias in them. The findings and recommendations from this article can help in moving forward the synthesis of evidence of effectiveness not only in built environments and physical activity, but also more broadly in exercise science and public health.

Aerobic Capacity, Physical Activity and Metabolic Risk Factors in Firefighters Compared with Police Officers and Sedentary Clerks

Background

This study examined the association between the physical work environment and physiological performance measures, physical activity levels and metabolic parameters among German civil servants. A main focus in this study was to examine the group differences rather than measuring the absolute values in an occupational group.

Methods

We prospectively examined 198 male German civil servants (97 firefighters [FFs], 55 police officers [POs] and 46 sedentary clerks [SCs]). For each parameter, the groups were compared using a linear regression adjusted for age.

Results

The 97 FFs showed a similar maximal aerobic power (VO_2max l/min) of 3.17±0.44 l/min compared with the POs, who had a maximal aerobic power of 3.13±0.62 l/min (estimated difference, POs vs. FFs: 0.05, CI: -0.12-0.23, p=0.553). The maximal aerobic power of the FFs was slightly higher than that of the SCs, who had a maximal aerobic power of 2.85±0.52 l/min (-0.21, CI: -0.39-0.04, p=0.018 vs. FFs). The average physical activity (in metabolic equivalents [METS]/week) of the FFs was 3818.8±2843.5, whereas those of the POs and SCs were 2838.2±2871.9 (-808.2, CI: 1757.6-141.2, p=0.095) and 2212.2±2292.8 (vs. FFs: -1417.1, CI: -2302-531.88, p=0.002; vs. POs: -2974.4, CI: -1611.2-393.5, p=0.232), respectively. For the FFs, the average body fat percentage was 17.7%±6.2, whereas it was 21.4%±5.6 for the POs (vs. FFs: 2.75, CI: 0.92-4.59, p=0.004) and 20.8%±6.5 for the SCs (vs. FFs: 1.98, CI: -0.28-4.25, p=0.086; vs. POs: -0.77, CI: 3.15-1.61, p=0.523). The average waist circumference was 89.8 cm±10.0 for the FFs, 97.8 cm±12.4 (5.63, CI: 2.10-9.15, p=0.002) for the POs, and 97.3±11.7 (vs. FFs: -4.89, CI: 1.24-8.55, p=0.009; vs. POs: -0.73, CI: -5.21-3.74, p=0.747) for the SCs.

Conclusions

The FFs showed significantly higher physical activity levels compared with the SCs. The PO group had the highest cardiovascular risk of all of the groups because it included more participants with metabolic syndrome; furthermore, the POs had an average of 2.75% higher body fat, lower HDL cholesterol values and higher waist circumferences compared with the FFs and higher LDL cholesterol values compared with the SCs. Our data indicate that sedentary occupations appear to be linked to obesity and metabolic syndrome in middle-aged men.

Prolonged Sitting Time: Barriers, Facilitators and Views on Change among Primary Healthcare Patients Who Are Overweight or Moderately Obese

BACKGROUND AND OBJECTIVES

Prolonged sitting time has negative consequences on health, although the population is not well aware of these harmful effects. We explored opinions expressed by primary care patients diagnosed as overweight or moderately obese concerning their time spent sitting, willingness to change, and barriers, facilitators, goals and expectations related to limiting this behaviour.

METHODS

A descriptive-interpretive qualitative study was carried out at three healthcare centres in Barcelona, Spain, and included 23 patients with overweight or moderate obesity, aged 25 to 65 years, who reported sitting for at least 6 hours a day. Exclusion criteria were inability to sit down or stand up from a chair without help and language barriers that precluded interview participation. Ten in-depth, semi-structured interviews (5 group, 5 individual) were audio recorded from January to July 2012 and transcribed. The interview script included questions about time spent sitting, willingness to change, barriers and facilitators, and the prospect of assistance from primary healthcare professionals. An analysis of thematic content was made using ATLAS.Ti and triangulation of analysts.

RESULTS

The most frequent sedentary activities were computer use, watching television, and motorized journeys. There was a lack of awareness of the amount of time spent sitting and its negative consequences on health. Barriers to reducing sedentary time included work and family routines, lack of time and willpower, age and sociocultural limitations. Facilitators identified were sociocultural change, free time and active work, and family surroundings. Participants recognized the abilities of health professionals to provide help and advice, and reported a preference for patient-centred or group interventions.

CONCLUSIONS

Findings from this study have implications for reducing sedentary behaviour. Patient insights were used to design an intervention to reduce sitting time within the frame of the SEDESTACTIV clinical trial.

Temporal changes in occupational sitting time in the Danish workforce and associations with all-cause mortality: results from the Danish work environment cohort study

BACKGROUND

Prolonged sitting has been negatively associated with a range of non-communicably diseases. However, the role of occupational sitting is less clear, and little is known on the changes of occupational sitting in a working population over time. The present study aimed to determine 1) temporal changes in occupational sitting time between 1990 and 2010 in the Danish workforce; 2) the association and possible dose-response relationship between occupational sitting time and all-cause mortality.

METHODS

This study analysed data from the Danish Work Environment Cohort Study (DWECS), which is a cohort study of the Danish working population conducted in five yearly intervals between 1990 and 2010. Occupational sitting time is self-reported in the DWECS. To determine the association with all-cause mortality, the DWECS was linked to the Danish Register of Causes of Death via the Central Person Register.

RESULTS

Between 1990 and 2010 the proportion of the Danish workforce who sat for at least three quarters of their work time gradually increased from 33.1 to 39.1%. All-cause mortality analyses were performed with 149,773 person-years of observation and an average follow-up of 12.61 years, during which 533 deaths were registered. None of the presented analyses found a statistically significant association between occupational sitting time and all-cause mortality. The hazard ratio for all-cause mortality was 0.97 (95% CI: 0.79; 1.18) when ≥24 hr/wk occupational sitting time was compared to <24 hr/wk for the 1990-2005 waves.

CONCLUSIONS

Occupational sitting time increased by 18% in the Danish workforce, which seemed to be limited to people with high socio-economic status. If this increase is accompanied by increases in total sitting time, this development has serious public health implications, given the detrimental associations between total sitting time and mortality. The current study was inconclusive on the specific role that occupational sitting might play in the increased all-cause mortality risk associated with the total volume of sitting.

Repetitive daily point of choice prompts and occupational sit-stand transfers, concentration and neuromuscular performance in office workers: an RCT

Objective: Prolonged office sitting time adversely affects neuromuscular and cardiovascular health parameters. As a consequence, the present study investigated the effects of prompting the use of height-adjustable working desk (HAWD) on occupational sitting and standing time, neuromuscular outcomes and concentration in office workers. Methods: A single-blinded randomized controlled trial (RCT) with parallel group design was conducted. Thirty-eight office workers were supplied with HAWDs and randomly assigned (Strata: physical activity (PA), BMI, gender, workload) to a prompt (INT) or non-prompt (CON) group. INT received three daily screen-based prompts within 12 weeks. CON was only instructed once concerning the benefits of using HAWDs prior to the start of the study. Sitting and standing times were objectively assessed as primary outcomes for one entire working week using the ActiGraph wGT3X-BT at baseline (pre), after 6 (mid) and 12 weeks (post). Concentration (d2-test), postural sway during upright stance (under single, dual and triple task) and lower limb strength endurance (heel-rise) were collected as secondary outcomes. Results: With large but not statistically significant within group effects from pre to post, INT increased weekly standing time at work by 9% (p = 0.22, d = 0.8) representing an increase from 7.2 h (4.8) to 9.7 (6.6) h (p = 0.07). Concentration and neuromuscular performance did not change from pre to post testing (0.23 < p < 0.95; 0.001 < η_p² < 0.05). Conclusion: Low-frequent and low cost screen-based point of choice prompts (3 per day within 12 weeks) already result in notable increases of occupational standing time of approx. daily 30 min. These stimuli, however, did not relevantly affect neuromuscular outcomes.  

Patterns of impact resulting from a 'sit less, move more' web-based program in sedentary office employees

PURPOSE

Encouraging office workers to 'sit less and move more' encompasses two public health priorities. However, there is little evidence on the effectiveness of workplace interventions for reducing sitting, even less about the longer term effects of such interventions and still less on dual-focused interventions. This study assessed the short and mid-term impacts of a workplace web-based intervention (Walk@WorkSpain, W@WS; 2010-11) on self-reported sitting time, step counts and physical risk factors (waist circumference, BMI, blood pressure) for chronic disease.

METHODS

Employees at six Spanish university campuses (n=264; 42±10 years; 171 female) were randomly assigned by worksite and campus to an Intervention (used W@WS; n=129; 87 female) or a Comparison group (maintained normal behavior; n=135; 84 female). This phased, 19-week program aimed to decrease occupational sitting time through increased incidental movement and short walks. A linear mixed model assessed changes in outcome measures between the baseline, ramping (8 weeks), maintenance (11 weeks) and follow-up (two months) phases for Intervention versus Comparison groups.

RESULTS

A significant 2 (group) × 2 (program phases) interaction was found for self-reported occupational sitting (F[3]=7.97, p=0.046), daily step counts (F[3]=15.68, p=0.0013) and waist circumference (F[3]=11.67, p=0.0086). The Intervention group decreased minutes of daily occupational sitting while also increasing step counts from baseline (446±126; 8,862±2,475) through ramping (+425±120; 9,345±2,435), maintenance (+422±123; 9,638±3,131) and follow-up (+414±129; 9,786±3,205). In the Comparison group, compared to baseline (404±106), sitting time remained unchanged through ramping and maintenance, but decreased at follow-up (-388±120), while step counts diminished across all phases. The Intervention group significantly reduced waist circumference by 2.1cms from baseline to follow-up while the Comparison group reduced waist circumference by 1.3cms over the same period.

CONCLUSIONS

W@WS is a feasible and effective evidence-based intervention that can be successfully deployed with sedentary employees to elicit sustained changes on "sitting less and moving more".

Sedentary work--associations between five-year changes in occupational sitting time and body mass index

OBJECTIVE

The aim of this study is to investigate the association between five-year changes in occupational sitting and body mass index (BMI) in working adults.

METHODS

We analyzed data from The Danish Work Environment Cohort Study (2005 and 2010, n=3.482). Data on occupational sitting, weight, height and several potential confounders were self-reported. The association between change in occupational sitting (hours) (categorized as large decrease <-7.5, moderate decrease -7.5 to <-2.5, no change -2.5 to 2.5, moderate increase >2.5 to 7.5 and large increase >7.5) and change in BMI was explored by multiple linear regression analyses.

RESULTS

43.0% men and 36.1% women had high occupational sitting time (≥25h per week) at baseline. 31.8% men and 27.2% women decreased while 30.0% men and 33.0% women increased occupational sitting. The proportion of obese (BMI≥30) increased almost 3% for both genders. BMI changed 0.13 (CI: 0.06; 0.20, p=0.0003), per category of change in occupational sitting in women, but no association was found in men.

CONCLUSION

In women, there is a positive association between five-year changes in occupational sitting and BMI.

Acceptability and feasibility of potential intervention strategies for influencing sedentary time at work: focus group interviews in executives and employees

BACKGROUND

Occupational sitting can be the largest contributor to overall daily sitting time in white-collar workers. With adverse health effects in adults, intervention strategies to influence sedentary time on a working day are needed. Therefore, the present aim was to examine employees' and executives' reflections on occupational sitting and to examine the potential acceptability and feasibility of intervention strategies to reduce and interrupt sedentary time on a working day.

METHODS

Seven focus groups (four among employees, n = 34; three among executives, n = 21) were conducted in a convenience sample of three different companies in Flanders (Belgium), using a semi-structured questioning route in five themes [personal sitting patterns; intervention strategies during working hours, (lunch) breaks, commuting; and intervention approach]. The audiotaped interviews were verbatim transcribed, followed by a qualitative inductive content analysis in NVivo 10.

RESULTS

The majority of participants recognized they spend their working day mostly sitting and associated this mainly with musculoskeletal health problems. Participants suggested a variety of possible strategies, primarily for working hours (standing during phone calls/meetings, PC reminders, increasing bathroom use by drinking more water, active sitting furniture, standing desks, rearranging the office) and (lunch) breaks (physical activity, movement breaks, standing tables). However, several barriers were reported, including productivity concerns, impracticality, awkwardness of standing, and the habitual nature of sitting. Facilitating factors were raising awareness, providing alternatives for simply standing, making some strategies obligatory and workers taking some personal responsibility.

CONCLUSIONS

There are some strategies targeting sedentary time on a working day that are perceived to be realistic and useful. However several barriers emerged, which future trials and practical initiatives should take into account.

Surveying the Impact of Work Hours and Schedules on Commercial Motor Vehicle Driver Sleep

Background

Given the long hours on the road involving multiple and interacting work stressors (i.e., delivery pressures, irregular shifts, ergonomic hazards), commercial drivers face a plethora of health and safety risks. Researchers goal was to determine whether and to what extent long-haul trucker work schedules influence sleep duration and quality.

Methods

Survey and biometric data collected from male long-haul truck drivers at a major truckstop in central North Carolina over a six month period.

Results

Daily hours worked (mean = 11 hours, 55 minutes) and frequency of working over government-mandated daily HOS regulations (23.8% “frequently or always”) were statistically significant predictors of sleep duration. Miles driven per week (mean = 2,812.61), irregular daily hours worked (63.8%), and frequency of working over the daily hour limit (23.8% “frequently or always”) were statistically significant predictors of sleep quality.

Conclusion

Implications of findings suggest a comprehensive review of the regulations and operational conditions for commercial motor vehicle drivers be undertaken.

Workplace interventions for reducing sitting at work

BACKGROUND

The number of people working whilst seated at a desk keeps increasing worldwide. As sitting increases, occupational physical strain declines at the same time. This has contributed to increases in cardiovascular disease, obesity and diabetes. Therefore, reducing and breaking up the time that people spend sitting while at work is important for health.

OBJECTIVES

To evaluate the effects of workplace interventions to reduce sitting at work compared to no intervention or alternative interventions.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, OSH UPDATE, PsycINFO, Clinical trials.gov and the World Health Organization (WHO) search trial portal up to 14 February, 2014. We also searched reference lists of articles and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCT), cluster-randomised controlled trials (cRCTs), and quasi-randomised controlled trials of interventions to reduce sitting at work. For changes of workplace arrangements, we also included controlled before-and-after studies (CBAs) with a concurrent control group. The primary outcome was time spent sitting at work per day, either self-reported or objectively measured by means of an accelerometer coupled with an inclinometer. We considered energy expenditure, duration and number of sitting episodes lasting 30 minutes or more, work productivity and adverse events as secondary outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full-text articles for study eligibility. Two review authors independently extracted data and assessed risk of bias. We contacted authors for additional data where required.

MAIN RESULTS

We included eight studies, four RCTs, three CBAs and one cRCT, with a total of 1125 participants. The studies evaluated physical workplace changes (three studies), policy changes (one study) and information and counselling (four studies). No studies investigated the effect of treadmill desks, stepping devices, periodic breaks or standing or walking meetings. All the studies were at high risk of bias. The quality of the evidence was very low to low. Half of the studies were from Australia and the other half from Europe, with none from low- or middle-income countries. Physical workplace changesWe found very low quality evidence that sit-stand desks with or without additional counselling reduced sitting time at work per workday at one week follow-up (MD -143 minutes (95% CI -184 to -102, one study, 31 participants) and at three months' follow-up (MD - 113 minutes, 95% CI -143 to -84, two studies, 61 participants) compared to no intervention. Total sitting time during the whole day decreased also with sit-stand desks compared to no intervention (MD -78 minutes, 95% CI -125 to -30, one study, 31 participants) as did the duration of sitting episodes lasting 30 minutes or more (MD -52 minutes, 95% CI -79 to -26, two studies, 74 participants). Sit-stand desks did not have a considerable effect on work performance and had an inconsistent effect on musculoskeletal symptoms and sick leave. Policy changesWalking strategies had no considerable effect on sitting at work (MD -16 minutes, 95% CI -54 to 23, one study, 179 participants, low quality evidence). Information and counsellingGuideline-based counselling by occupational physicians reduced sitting time at work (MD -28 minutes, 95% CI -54 to -2, one study, 396 participants, low quality evidence). There was no considerable effect on reduction in total sitting time during the whole day.Mindfulness training induced a non-significant reduction in workplace sitting time (MD -2 minutes, 95% CI -22 to 18) at six months' follow-up and at 12 months' follow-up (MD -16 minutes, 95% CI -45 to 12, one study, 257 participants, low quality evidence).There was an inconsistent effect of computer prompting on sitting time at work. One study found no considerable effect on sitting at work (MD -18 minutes, 95% CI -53 to 17, 28 participants, low quality evidence) at 10 days' follow-up, while another study reported a significant reduction in sitting at work (MD -55 minutes, 95% CI -96 to -14, 34 participants, low quality evidence) at 13 weeks' follow-up. Computer prompting software also led to a non-significant increase in energy expenditure at work (MD 278 calories/workday, 95% CI 0 to 556, one study, 34 participants, low quality evidence) at 13 weeks' follow-up.

AUTHORS' CONCLUSIONS

At present there is very low quality evidence that sit-stand desks can reduce sitting time at work, but the effects of policy changes and information and counselling are inconsistent. There is a need for high quality cluster-randomised trials to assess the effects of different types of interventions on objectively measured sitting time. There are many ongoing trials that might change these conclusions in the near future.

Facilitators and barriers to using treadmill workstations under real working conditions: a qualitative study in female office workers

PURPOSE

Characterize barriers and facilitators to use treadmill workstations in real work sites.

DESIGN

For 6 months, workers tried a sit-stand-walk treadmill workstation at will with expert ergonomic support. Qualitative data were collected monthly.

SETTING

Administrative and academic departments at a higher education institution in Massachusetts, United States.

PARTICIPANTS

Five female administrative office workers.

METHOD

One monthly group interview and one personal interview per participant during 6 months. Emerging topics from previous interviews were used in successive data gatherings. Transcribed data were manually coded according to the predefined topics of usability, comfort, safety, and productivity.

RESULTS

The setup of the work station, communication difficulties while walking (disrespectful, noisy), and peer pressure to maximize use were the main usability barriers. There was no event of falls. Trips were minimized. About comfort, subjects reported it hard to get used to prolonged standing position during the first month. Treadmill speed affected productivity mostly while drawing and working in spreadsheets. Lack of job autonomy was revealed as a generic barrier.

CONCLUSION

In this female group, treadmill workstations had serious design problems for workers with not enough control of their jobs. The early identification and removal of barriers likely needs to be considered when offering these workstations to workers with low job autonomy.

Is sitting worse than static standing? How a gender analysis can move us toward understanding determinants and effects of occupational standing and walking

The Yant Award was established in 1964 to honor the contributions of William P. Yant, the first president of the American Industrial Hygiene Association. It is presented annually for outstanding contributions in industrial hygiene or allied fields to an individual residing outside the United States. The 2014 award recipient is Dr. Karen Messing, Professor emeritus, Department of Biological Sciences, Université du Québec à Montréal and Researcher, CINBIOSE Research Centre. Gender (socially determined) differences in occupations, employment, and working conditions, task assignments, and work methods that affect exposure to health risks are increasingly documented. Interactions of (biologically influenced) sex differences with workplace parameters may also influence exposure levels. During field studies, ergonomists learn a lot about gender and sex that can be important when generating and testing hypotheses about the mechanisms that link workplace exposures to health outcomes. Prolonged standing is common in North America; almost half (45%) of Québec workers spend more than three-quarters of their working time on their feet and 40% of these cannot sit at will. This posture has been linked to chronic back pain and musculoskeletal disorders (MSDs) in the lower limbs, but many health professionals suggest workers should stand rather than sit at work. We ask: (1) Given the fact that roughly the same proportion of men and women stand at work, what does a gender-sensitive analysis add to our ability to detect and thus prevent work-related MSDs?; (2) How does ergonomics research inform gender-sensitive analysis of occupational health data?; and (3) What do researchers need to know to orient interventions to improve general working postures? We have sought answers to these questions through collaborative research with specialists in epidemiology, occupational medicine, biomechanics, and physiology, carried out in partnership with public health organisations, community groups, and unions. We conclude that failure to characterize prolonged static standing and to apply gender-sensitive analysis can confuse assessment of musculoskeletal and circulatory effects of working postures. We suggest that prolonged static sitting and standing postures can and should be avoided by changes to workplace organization and environments. Research is needed to define optimal walking speeds and arrive at optimal ratios of sitting, standing, and walking in the workplace.

Socio-demographic, behavioural and cognitive correlates of work-related sitting time in German men and women

BACKGROUND

Sitting time is ubiquitous for most adults in developed countries and is most prevalent in three domains: in the workplace, during transport and during leisure time. The correlates of prolonged sitting time in workplace settings are not well understood. Therefore, the aim of this study was to examine the gender-specific associations between the socio-demographic, behavioural and cognitive correlates of work-related sitting time.

METHODS

A cross-sectional sample of working German adults (n = 1515; 747 men; 43.5 ± 11.0 years) completed questionnaires regarding domain-specific sitting times and physical activity (PA) and answered statements concerning beliefs about sitting. To identify gender-specific correlates of work-related sitting time, we used a series of linear regressions.

RESULTS

The overall median was 2 hours of work-related sitting time/day. Regression analyses showed for men (β = -.43) and for women (β = -.32) that work-related PA was negatively associated with work-related sitting time, but leisure-related PA was not a significant correlate. For women only, transport-related PA (β = -.07) was a negative correlate of work-related sitting time, suggesting increased sitting times during work with decreased PA in transport. Education and income levels were positively associated, and in women only, age (β = -.14) had a negative correlation with work-related sitting time. For both genders, TV-related sitting time was negatively associated with work-related sitting time. The only association with cognitive correlates was found in men for the belief 'Sitting for long periods does not matter to me' (β = .10) expressing a more positive attitude towards sitting with increasing sitting durations.

CONCLUSIONS

The present findings show that in particular, higher educated men and women as well as young women are high-risk groups to target for reducing prolonged work-related sitting time. In addition, our findings propose considering increasing transport-related PA, especially in women, as well as promoting recreation-related PA in conjunction with efforts to reduce long work-related sitting times.

Biobehavioral factors mediate exercise effects on fatigue in breast cancer survivors

PURPOSE

This study aimed to examine mediators of fatigue response to an exercise intervention for breast cancer survivors in a pilot randomized controlled trial.

METHODS

Postmenopausal breast cancer survivors (n = 46; ≤stage 2), off primary treatment, and reporting fatigue and/or sleep dysfunction were randomized to a 3-month exercise intervention (160 min·wk of moderate-intensity aerobic walking, twice weekly resistance training with resistance bands) or control group. Six discussion group sessions provided behavioral support to improve adherence. Fatigue, serum cytokines, accelerometer physical activity, cardiorespiratory fitness, sleep dysfunction, and psychosocial factors were assessed at baseline and 3 months.

RESULTS

The exercise intervention effect sizes for fatigue were as follows: fatigue intensity d = 0.30 (P = 0.34), interference d = -0.38 (P = 0.22), and general fatigue d = -0.49 (P = 0.13). Using the Freedman-Schatzkin difference-in-coefficients tests, increase in fatigue intensity was significantly mediated by interleukin 6 (IL-6) (82%), IL-10 (94%), IL-6/IL-10 (49%), and tumor necrosis factor-α (TNF-α):IL-10 (78%) with reduced sleep dysfunction increasing the relationship between intervention and fatigue intensity rather than mediating intervention effects (-88%). Decrease in fatigue interference was mediated by sleep dysfunction (35%), whereas IL-10 and pro-anti-inflammatory cytokine ratios increased the relationship between intervention and interference (-25% to -40%). The reduction in general fatigue was significantly mediated by minutes of physical activity (76%), sleep dysfunction (45%), and physical activity enjoyment (40%), with IL-10 (-40%) and IL-6/IL-10 (-11%) increasing the intervention-fatigue relationship. In the intervention group, higher baseline fatigue, anxiety, depression, and perceived exercise barrier interference predicted a greater decline in fatigue interference and/or general fatigue during the intervention.

CONCLUSIONS

Biobehavioral factors mediated and enhanced intervention effects on fatigue, whereas psychosocial factors predicted fatigue response. Further study is warranted to confirm our results and to improve understanding of relationships that mediate and strengthen the intervention-fatigue association.