Occupational physical activity and mortality among Danish workers

Interactive associations of smoking and physical activity with metabolic syndrome in adult men in Korea

Introduction

This study aimed to investigate the association of smoking and physical activity (PA) with metabolic syndrome (MetS) in adult men in Korea.

Methods

This study analyzed data of 7,229 adult men aged 19-64 years obtained from the 2014-2021 Korea National Health and Nutrition Examination Survey (KNHANES). Information on smoking habits was obtained using KNHANES data, while that on total PA (TPA), leisure-time PA (LTPA), and occupational PA (OPA) was collected using the Global Physical Activity Questionnaire. Smoking status was classified into non-smokers and smokers, and PA was categorized into three groups (total, leisure time, and occupational) according to the time spent engaging in moderate or high-intensity PA areas. The diagnosis of MetS was based on the Adult Treatment Program III of the National Cholesterol Education Program and Koreans' waist circumference criteria.

Results

Logistic regression revealed that the risk of MetS was significantly lower in non-smokers than in smokers, even after adjusting for all covariates. The risk of MetS was significantly lower in individuals who engaged in at least 150 min of moderate- and high-intensity TPA or LTPA per week than in those who did not engage in PA. Furthermore, smokers who engaged in at least 150 min of moderate- to high-intensity TPA and LTPA per week had a significantly lower risk of MetS than those who did not engage in PA. Meanwhile, OPA was not associated with MetS.

Conclusion

The findings suggest that engaging in moderate- to high-intensity TPA or LTPA for at least 150 min per week attenuates the risk of MetS caused by smoking.

Work, travel, or leisure: comparing domain-specific physical activity patterns based on rural-urban location in Canada

BACKGROUND

Physical activity occurs across various domains including leisure/recreation, for transportation, or for work or household reasons. Rural and urban active living environments are characterized by different opportunities for physical activity within each domain which may translate into different patterns of behavior. The aim of this study was to compare rural-urban differences in physical activity across different domains, and explore interactions between sociodemographic factors, physical activity domains, and rurality.

METHODS

We used self-reported data collected across three physical activity domains (active transportation, recreation, occupational/household) and relevant sociodemographic variables from the Canadian Community Health Survey. Adjusting for sociodemographic factors, we did two separate cross-sectional analyses: 1) binary logistic regression to determine the odds of reporting any activity in each domain, and 2) ordinary least squares regression using the sub-samples reporting > 0 min per week of activity to compare how much activity was reported in each domain.

RESULTS

Our final survey weighted sample of Canadian adults (mean age 47.4 years) was n = 25,669,018 (unweighted n = 47,266). Rural residents were less likely to report any active transportation (OR = 0.59, 95% CI [0.51, 0.67], p < .0001). For recreational physical activity, rural males had lower odds (OR = 0.75, 95% CI [0.67, 0.83], p < .0001) and rural females had higher odds (OR = 1.19, 95% CI [1.08, 1.30], p = .0002) of reporting any participation compared to urban residents. Rural males (OR = 1.90, 95% CI [1.74, 2.07], p < .0001) and females (OR = 1.33, 95% CI [1.21, 1.46], p < .0001) had higher odds of reporting any occupational or household physical activity.

CONCLUSIONS

Urban residents tend to participate in more active transportation, while rural residents participate in more occupational or household physical activity. Location-based differences in physical activity are best understood by examining multiple domains and must include appropriate sociodemographic interactions, such as income and sex/gender.

Occupational physical activity: the good, the bad, and the proinflammatory

Background

Physical activity (PA) is beneficial for preventing several conditions associated with underlying chronic inflammation, e. g., cardiovascular disease (CVD) and cancer. While an active lifestyle appears to have anti-inflammatory effects, high levels of occupational PA (OPA) were associated with inflammation and elevated mortality risks. We aimed to summarize the current knowledge (1) on the association between inflammation and OPA and (2) its implications for health and mortality.

Methods and results

This mini-review summarized relevant literature published before January 2023 using established scientific databases and sources. For the primary outcome, observational studies (S) reporting immunological effects (O) in subjects (P), with high (I) vs. low OPA (C), were included. For secondary outcomes, i.e., morbidity and mortality associated with inflammatory processes, (systematic) reviews were included. While "active" occupations and "moderate" OPA appear to have beneficial effects, low (particularly sedentary) and "high-intensity" OPA (particularly including heavy lifting tasks) were associated with inflammation and (CVD and cancer-related) mortality; higher leisure-time PA has been almost consistently associated with lower proinflammatory markers and all-cause mortality risks. Workplace interventions appear to counter some of the observed health effects of unfavorable work strain.

Conclusion

The few studies addressing OPA "intensity" and inflammatory markers are largely heterogeneous regarding OPA classification and confounder control. Sedentary and "heavy" OPA appear to promote proinflammatory effects. In addition to targeted management of work-related physical strain and hazardous environmental co-factors, occupational health providers should focus on employer-initiated exercise interventions and the promotion of leisure-time PA.

Exposure to environmental occupational constraints and all-cause mortality: Results for men and women from a 20-year follow-up prospective cohort, the VISAT study. Be aware of shift-night workers!

Objective

To determine the predictive value of the large panel of occupational constraints (OC) on all-cause mortality with a 20-year follow-up, in general population of workers.

Methods

In VISAT prospective cohort study, 3,138 workers (1,605 men; 1,533 women) were recruited during the periodic work health visits conducted by occupational physicians. OC (physical, organizational, psychological and employment categories) were collected through self-questionnaires. Exposure durations of each OC were divided by tertile distribution. Cox-regression models were performed to analyze the associations between all-cause mortality and each OC first separately and simultaneously in a single model.

Results

The mortality rates were higher among exposed participants to most of OC compared to those unexposed. Being exposed and longer exposure increased the risks of all-cause mortality for exposures to carrying heavy loads, loud noise, working more than 48 h/week, starting its first job before 18 years old although these risks became non-significant after adjustments for cardiovascular risk factors. Shift work and night work confirmed a high risk of mortality whatever the adjustments and notably when the other occupational exposures were taking into account, with, respectively: HR: 1.38 (1.01-1.91) and 1.44 (1.06-1.95). After adjustments being exposed more than 13 years to a work requiring getting-up before 5:00 a.m. and more than 16 years in rotating shift work significantly increased the risk of mortality by one and a half.

Conclusion

The links between each OC and all-cause mortality and the role of individual factors were stressed. For night-shift workers, it is urgent to implement preventive strategies at the workplace.

Revisiting the 'physical activity paradox' in a Chinese context: Occupational physical activity and mortality in 142,302 urban working adults from the China Kadoorie Biobank study

BACKGROUND

Previous research suggests that while leisure-time physical activity (LTPA) is beneficial, occupational physical activity (OPA) may be detrimental to health, known as the 'physical activity paradox'. However, the current evidence is primarily based on data from Western countries. We examined the association of OPA with all-cause and cardiovascular disease mortality in working adults in urban China.

METHODS

This prospective longitudinal study was based on a sample of 142,302 urban working adults aged 30-79 years from the China Kadoorie Biobank study. Self-reported OPA (mainly sedentary, standing occupation, and manual work) was collected at baseline (year 2004-2008) and linked to death registries until 31st December 2016. Multivariable Cox proportional hazards models were used to examine the relationship between OPA and mortality outcomes, with further tests for effect modification by sex, educational attainment and LTPA.

FINDINGS

During a median follow-up of 10·2 years, 4,077 deaths occurred, of which cardiovascular disease was the primary cause for 727 deaths. Crude modelling showed that compared with the sedentary workers, manual work was associated with increased risk of all-cause mortality. However, after adjusting for socio-demographic and lifestyle variables, the association was attenuated to null (HR=1·00, 95%CI: 0·93-1·08). In subgroup analysis, higher OPA was associated with lower risk of all-cause mortality in the least educated group (HR=0·84, 95%CI: 0·75-0·95 for manual work, and HR=0·86, 95%CI: 0·75-0·99 for standing occupation), but harmful in the most educated group (HR=1·17, 95%CI: 1·01-1·36) and in those who reported regular LTPA (HR=1·20, 95%CI: 1·01-1·43).

INTERPRETATION

OPA was not associated with mortality risk in the overall sample. However, findings support the 'physical activity paradox' within better educated Chinese workers.

FUNDING

None.

Occupational and Leisure Physical Activity on Cardiovascular Risk and Body Composition Among Courier Workers

OBJECTIVE

There is some controversy about the beneficial effects of occupational physical activity (OPA) on cardiovascular risk (CVR). The main aim of this study was to explore the effect of the combination of different frequencies of leisure-time physical activity (LTPA) and two types of OPA on CVR and body composition, and whether the association between physical activity (PA) and CVR was mediated by visceral adipose tissue (VAT).

METHODS

This cross-sectional study included data from 2516 couriers living in Spain, delivering either by motorbike or foot, and practicing LTPA never, occasionally, or regularly. Couriers were classified into six categories according to LTPA and OPA; body composition was assessed by Bioelectrical Impedance, and CVR by the Framingham equation. General linear models were performed to explore the association between different categories with each outcome (CVR and body composition) and the possible role of VAT as a mediator between PA and CVR.

RESULTS

Compared with the most sedentary group (motorbike couriers that never practice PA), walking couriers who practice regular PA presented the lowest CVR [β -1.58 (95% CI -2.31; -0.85)] and the lowest VAT [β -2.86 (95% CI -3.74; -1.98) followed by the motorbike couriers who practiced regular PA [β -0.51 (95% CI -1.00; -0.03) for CVR and β -2.33 (95% CI -2.91; -1.75) for VAT]. The association between PA and CVR was partially mediated by VAT.

CONCLUSION

The present results indicated that both OPA and LTPA are protective factors for CVR and play an important role on VAT accumulation.

Association of Physical Activity and Sedentary Behavior With the Risk of Colorectal Cancer

BACKGROUND

Although recent evidence supports that prolonged sedentary behavior and reduced physical activity are associated with colorectal cancer risk, there are few studies analyzing the colorectal cancer risk according to different types of physical activity and combined effects of sedentary behavior and physical activity on colorectal cancer. This study aimed to investigate the association of sedentary behavior and physical activity with colorectal cancer.

METHODS

A cross-sectional study included a total of 33,403 participants from the Korea National Health and Nutrition Examination Survey from 2014 to 2019. Sedentary behavior was dichotomized into < 10 hr/day and ≥ 10 hr/day, and three types of physical activity were investigated, including leisure-time, occupational, and transportation physical activity. Multiple logistic regression analyses were performed to assess the risk of colorectal cancer in relation to sedentary behavior and physical activity.

RESULTS

Sedentary behavior was associated with an increased risk of colorectal cancer (odds ratio [OR] 1.64; 95% confidence interval [CI], 1.22-2.21), while the different domains of physical activity were not significantly associated with colorectal cancer risk. In a combined analysis, those with sedentary behavior and without physical activity showed an increased risk of colorectal cancer compared to that of the reference category without sedentary behavior and with physical activity (OR, 1.49; 95% CI, 1.02-2.16).

CONCLUSION

This study found that sedentary behavior was significantly associated with the increased risk of colorectal cancer. Moreover, sedentary behavior without physical activity increased the risk of colorectal cancer. Reducing sedentary behavior and recommending any type of physical activity may reduce the risk of colorectal cancer.

Associations of occupational and leisure-time physical activity with self-rated health in Korea

Recent findings have suggested that not all physical activity (PA) types improve health and that the health effects of occupational PA (OPA) and leisure-time PA (LTPA) can be different. However, few studies have been reported the association of OPA and LTPA with self-rated health (SRH). Therefore, we aimed to examine the association between different PA domains and general health and the impact of LTPA on the relationship between health and OPA. In total, 33440 adults from the Korea National Health and Nutrition Examination Survey 2014-2019 were analyzed in September 2021. SRH was dichotomized into "poor" and "good." Sedentary behavior (SB) was evaluated by measuring the daily sitting time. Multiple logistic regression was used to investigate the relationship of SRH with OPA, LTPA, and SB, stratified by LTPA to identify its impact on the relationship. In the fully adjusted model, OPA was found to increase the risk of poor SRH, while LTPA was found to lower the risk. In those who did not engage in LTPA, OPA and poor SRH were significantly associated. Poor SRH was not significantly associated with OPA in those who engaged in LTPA. SB was also associated with poor SRH, independent of LTPA. To improve health, it is important to promote LTPA and reduce OPA and SB. In particular, for workers with a higher level of OPA, additional LTPA should be introduced to prevent SRH from worsening.

Intensity of occupational physical activity in blue-collar workers: do self-reported rating and device-worn measurements agree?

PURPOSE

High intensity occupational physical activity (OPA) seem to aggravate health and increase risk of sick leave and early retirement. Most intensity of OPA monitoring has been self-reported, e.g. by rating of perceived exertion (RPE). However, no studies have investigated the precision and risk of bias in RPE reporting during free-living OPA. This study investigated the agreement between OPA intensity in percentage of the heart rate reserve (%HRR) estimated from RPE and device-measured heart rate (HR), and potential bias factors on this agreement.

METHODS

The CR10 scale measured RPE at work. The Actiheart monitor measured HR during 24-h a day for 2-4 days. Both RPE and device-worn HR were converted to %HRR. The difference between both %HRR and their limits of agreement was determined in a Bland Altman plot. To detect bias factors, the difference between both %HRR was regressed on age, sex, cardiorespiratory fitness, occupational lifting, medication, consequences of musculoskeletal disorders and the interactions between these factors with device-work %HRR.

RESULTS

Six hundred and twenty-three participants were included in the analysis. Mean difference between RPE-based and device-worn %HRR was 54.6% (SD 19.5). The limits of agreement were wide (11.6-90.1%HRR). Age (0.48%HRR, 95% CI 0.18-0.79) occupational lifting (9.84%HRR, 95% CI 3.85-15.83) and cardiorespiratory fitness (0.41%HRR, 95% CI 0.03-0.79) significantly biased the agreement between the estimations of OPA intensity.

CONCLUSION

RPE overestimated OPA intensity, and was biased by several factors. Device-worn %HRR should be preferred when evaluating OPA intensity among workers with physically demanding jobs.

Association of occupational sitting with cardiovascular outcomes and cardiometabolic risk factors: a systematic review with a sex-sensitive/gender-sensitive perspective

OBJECTIVES

Sedentary behaviour is a modifiable risk factor for cardiovascular health. Although long periods of sedentary behaviour take place at work, evidence of the relationship between such occupational sitting and cardiometabolic health risks remains limited. This systematic review aimed to update the evidence on the associations of occupational sitting with cardiovascular outcomes and cardiometabolic risk factors based on longitudinal studies.

DESIGN

Systematic review.

SETTING

Workplace.

POPULATION

Employees aged 18-65 years.

PRIMARY AND SECONDARY OUTCOMES

Primary outcomes were cardiovascular diseases and cardiometabolic risk markers. The secondary outcome was all-cause mortality.

DATA SOURCES

Ten databases, including PubMed, Web of Science and CINAHL (search January 2018, updated February 2019).

DATA EXTRACTION AND SYNTHESIS

Data were screened, extracted and appraised by three independent reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Studies were markedly heterogeneous in terms of measurement of occupational sitting, cardiometabolic risk factors and cardiovascular morbidity and mortality, so that standards were hardly identifiable and limiting the value of the evidence. The review included 27 high or acceptable quality publications. Of the eight high-quality publications from seven cohorts, three cohort studies found significant associations of occupational sitting with primary outcomes. Additionally, one study described an association with the secondary outcome. Another high-quality publication found an association between occupational sitting and ischaemic heart disease in a subgroup already at risk due to hypertension. For sex/gender analysis, 11 of the 27 high and acceptable quality publications reported sex-stratified results. Five of these found sex differences.

CONCLUSIONS

Evidence regarding the association of occupational sitting with cardiometabolic health risks was limited because of the lack of standardised measurements for occupational sitting. Occupational sitting combined with an overall sedentary lifestyle was associated with an elevated relative risk for several cardiometabolic outcomes. There is an urgent need for standardised measurements of occupational sitting to facilitate meta-analysis. Sex/gender aspects of this relationship require further investigation.

Lifetime high occupational physical activity and total and cause-specific mortality among 320 000 adults in the NIH-AARP study: a cohort study

OBJECTIVES

We examined the associations of history and duration in high occupational physical activity (OPA) with long-term total and cause-specific mortality.

METHODS

The sample included 322 126 participants (135 254 women) from the National Institutes of Health-AARP Diet and Health Study, established in 1995-1996. History and duration in high OPA were reported by participants. All-cause, cardiovascular, cancer and other cause mortality records available through 31 December 2011.

RESULTS

The prevalence of high OPA was 52.1% in men and 16.1% in women. During 13.6 years (SD, 3.3) of follow-up, 73 563 participants (25 219 women) died. In age-adjusted models, the risk of death was higher among men (HR 1.14, 95% CI 1.12 to 1.16) and women (HR 1.22, 95% CI 1.18 to 1.26) with a history of high OPA. However, these associations were substantially attenuated in women (HR 1.04, 95% CI 1.00 to 1.07, an 81.8% attenuation) and eliminated in men (HR 1.02, 95% CI 0.99 to 1.04, 85.7% attenuation) after multivariable adjustments. Similar important attenuation results were found when examining duration in high OPA, as well as using cause-specific deaths as the outcomes. Educational attainment and smoking patterns were the main contributors in the excess mortality among people working in highly physically active jobs in both men and women.

CONCLUSION

Participating in high OPA was not consistently associated with a higher mortality risk, after adjustments for education and smoking factors. Workers in high OPA should be aware that they might not be getting all well-known health benefits of being physically active if they are only very active at work.

Occupational Physical Activity and New-Onset Hypertension: A Nationwide Cohort Study in China

[Figure: see text].

The occupational sitting and physical activity questionnaire (OSPAQ): a validation study with accelerometer-assessed measures

Background

The Occupational Sitting and Physical Activity Questionnaire (OSPAQ) was developed as an easy-to-use instrument for self-reported assessment of percentage sitting, standing, walking, and performing heavy labour in a workplace setting. This study aimed to evaluate the concurrent validity of all dimensions of the OSPAQ compared to accelerometer-assessed measures of occupational physical activities in a mixed sample of sedentary and physically active professions.

Methods

Data from the Flemish Employees’ Physical Activity (FEPA) study were used, including employees from the service and production sector. All participants filled in a questionnaire, underwent clinical measurements, and wore two Axivity AX3 accelerometers for at least 2 consecutive working days. Intraclass (ICC) and Spearman rho correlations (r) were analyzed to assess concurrent validity.

Results

The sample included 401 workers (16% sedentary profession) with a mean age of 39.2 (± 11) years. Concurrent validity was good and moderate for assessing percentage of sitting (ICC = 0.84; r = 0.53), and standing (ICC = 0.64; r = 0.53), respectively. The concurrent validity for walking was weak to moderate (ICC = 0.50; r = 0.49), and weak for performing heavy labour (ICC = 0.28; r = 0.35). Stronger validity scores were found in sedentary professions for occupational sitting and standing. In physically active professions, an underestimation of self-reported sitting and standing was found, and an overestimation of self-reported walking and heavy labour. No significant self-reported over- or underestimation was found for sitting and heavy labour in sedentary professions, but an underestimation of self-reported standing and an overestimation of self-reported walking was observed.

Conclusions

The OSPAQ has acceptable measurement properties for assessing occupational sitting and standing. Accelerometer-assessed measures of occupational walking and heavy labour are recommended, since a poor concurrent validity was found for both.

Workplace activity classification from shoe-based movement sensors

Background

High occupational physical activity is associated with lower health. Shoe-based movement sensors can provide an objective measurement of occupational physical activity in a lab setting but the performance of such methods in a free-living environment have not been investigated. The aim of the current study was to investigate the feasibility and accuracy of shoe sensor-based activity classification in an industrial work setting.

Results

An initial calibration part was performed with 35 subjects who performed different workplace activities in a structured lab setting while the movement was measured by a shoe-sensor. Three different machine-learning models (random forest (RF), support vector machine and k-nearest neighbour) were trained to classify activities using the collected lab data. In a second validation part, 29 industry workers were followed at work while an observer noted their activities and the movement was captured with a shoe-based movement sensor. The performance of the trained classification models were validated using the free-living workplace data. The RF classifier consistently outperformed the other models with a substantial difference in in the free-living validation. The accuracy of the initial RF classifier was 83% in the lab setting and 43% in the free-living validation. After combining activities that was difficult to discriminate the accuracy increased to 96 and 71% in the lab and free-living setting respectively. In the free-living part, 99% of the collected samples either consisted of stationary activities or walking.

Conclusions

Walking and stationary activities can be classified with high accuracy from a shoe-based movement sensor in a free-living occupational setting. The distribution of activities at the workplace should be considered when validating activity classification models in a free-living setting.

Associations between occupational relative aerobic workload and resting blood pressure among different age groups: a cross-sectional analysis in the DPhacto study

OBJECTIVE

High levels of occupational physical activity (OPA) increase heart rate, blood pressure (BP) and the risk of hypertension. Older workers may be more vulnerable to high levels of OPA due to age-related degeneration of the cardiovascular system and cardiorespiratory fitness. This study investigates the association of relative aerobic workload (RAW) with resting BP and examines if this relation is moderated by age.

DESIGN

Cross-sectional epidemiological study.

SETTING

Data were collected among employees of 15 Danish companies in the cleaning, manufacturing and transport sectors.

PARTICIPANTS

2107 employees were invited for participation, of these 1087 accepted and 562 (42% female and 4% non-Westerns) were included in the analysis based on the criteria of being non-pregnant, no allergy to bandages, sufficient amount of heart rate data corresponding to ≥4 work hours per workday or 75% of average work hours, and no missing outcome and confounder values.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was BP.

RESULTS

Heart rate reserve was estimated from ambulatory 24-hour heart rate measures covering 2.5 workdays per participant (SD 1.0 day). Age significantly moderated the association between RAW and BP. Mean intensity and duration of high RAW (≥30% heart rate reserve) showed positive associations with diastolic BP and negative associations with pulse pressure (PP) among participants ≥47 years old. Tendencies towards negative associations between RAW and BP were seen among participants <47 years old.

CONCLUSIONS

Mean intensity and duration of RAW increased diastolic BP among participants ≥47 years old. Negative associations with PP may be due to healthy worker selection bias. Prevention of hypertension should consider reductions in RAW for ageing workers.

Undiagnosed Obstructive Sleep Apnea and Physical Activity in Older Manual Workers

Cardiovascular disease is a negative health outcome of obstructive sleep apnea (OSA). Risk factors associated with OSA development include low physical activity (PA), high body mass index (BMI), and increasing age (>50 years), and weight loss is usually recommended as treatment. This cross-sectional study examined the association between PA, BMI, and OSA severity in manual workers. Fifty-five participants (23 females and 32 males; mean age 55.2 years), were examined for OSA and completed a PA and anthropometric assessment. On average, OSA severity was mild, PA levels were moderate, and 32% of the sample was classified as obese. PA was negatively associated with OSA severity, but BMI strongly independently predicted OSA severity, with no evidence of mediation. As both PA and BMI were significantly associated with OSA in older manual workers, increasing PA should also be a focus of treatment for OSA.

Leisure time and occupational physical activity, resting heart rate and mortality in the Arctic region of Norway: The Finnmark Study

Aims

This study examined the association of leisure time physical activity, occupational physical activity, and resting heart rate with all-cause and cardiovascular disease mortality in Sami and non-Sami populations.

Study design

This was a longitudinal, observational population-based study.

Methods

The Finnmark 3 study cohort was examined in 1987–1988 and followed for all-cause and cardiovascular disease mortality for 26 years. The cohort included 17,697 men and women with a mean age of 47.2 years at baseline. Leisure time physical activity and occupational physical activity were assessed with a validated questionnaire at baseline, whereas cause of death was obtained from the Norwegian Cause of Death Registry.

Results

A total of 1983 women and 3147 men died during follow-up. Leisure time physical activity was linearly and inversely associated with all-cause mortality, but not coronary heart disease mortality. Compared to inactive subjects, all-cause mortality was significantly reduced by 16% in the active leisure time physical activity group (hazard ratio 0.84; 95% confidence interval 0.76–0.92). Both for all-cause and cardiovascular disease mortality, we observed a U-shaped relationship with occupational physical activity, as participants in the walking and lifting group had significantly lower mortality than both the mostly sedentary and the heavy manual labour group ( p < 0.05). An increase in resting heart rate by one beat per minute was associated with a 1.1% increase in all-cause mortality (hazard ratio 1.011; 95% confidence interval 1.009–1.013). The associations were similar in Sami and non-Sami subjects.

Conclusion

In this population-based study, leisure time physical activity was inversely associated with all-cause mortality, whereas resting heart rate was positively associated with all-cause and cardiovascular disease mortality. There was a U-shaped association between occupational physical activity and cardiovascular disease and all-cause mortality.

Physical heaviness of work and sitting at work as predictors of mortality: a 26-year follow-up of the Helsinki Birth Cohort Study

OBJECTIVES

To examine the relationships of late-career physical heaviness of work and sitting at work with mortality. A national-level job exposure matrix was used to determine the occupation-specific level of physical heaviness and sitting.

DESIGN

Prospective cohort study between years 1990 and 2015.

SETTING

Community.

PARTICIPANTS

5210 men and 4725 women from the Helsinki Birth Cohort Study with an occupational code at baseline (ages 45-57 years).

PRIMARY AND SECONDARY OUTCOME MEASURES

Total, cardiovascular (International Classification of Diseases 10th Revision I00-I99), cancer (C00-C97) and external (S00-Y84) mortality.

RESULTS

The exposures, physical heaviness and sitting had a non-linear, inverse relationship. During the 26-year follow-up, 1536 men and 759 women died. Among men, physical heaviness of work was positively associated and sitting at work was negatively associated with all-cause, cardiovascular and external cause mortality but they were not associated with cancer mortality. The HRs for men in the highest quartile of physical heaviness of work compared with men in the lowest quartile were 1.54 (1.31-1.80) for all-cause mortality, 1.70 (1.30-2.23) for cardiovascular mortality and 3.18 (1.75-5.78) for external cause mortality (adjusted for age and years of education). Compared with the lowest quartile, the HRs for the highest quartile of sitting at work among men were 0.71 (0.61-0.82) for all-cause mortality, 0.59 (0.45-0.77) for cardiovascular mortality and 0.38 (0.22-0.66) for external cause mortality. In women, neither physical heaviness of work nor sitting at work was associated with mortality.

CONCLUSIONS

Men in physically heavy work at their late-work career are at higher risk of death than men in physically light work.

Even a Previous Light-Active Physical Activity at Work Still Reduces Late Myocardial Infarction and Stroke in Retired Adults Aged>65 Years by 32%: The PROOF Cohort Study

Background: Work may contribute significantly to daily physical activity (PA) and sedentary behavior (SB). Physical inactivity and SB at work might be two major risk factors for premature morbidity. Therefore, the aim of this research was to describe self-reported past PA and SB at work and during leisure time within the PROOF cohort subjects, and to determine consequences of PA and SB on late health of these now retired workers.

Material and Methods: The PROOF cohort study was used to prospectively allow assessment of the predictive value of PA and SB at work and during leisure time among a healthy retired French population, with regard to cardiovascular and cerebrovascular events. PA (MET-h/week) and SB (h/d) were assessed using the Population Physical Activity Questionnaire (POPAQ) and the modified Global Physical Activity Questionnaire (GPAQ). Odds ratios (ORs with 95% CIs) for cardiovascular and cerebrovascular events were associated with each level of PA at work: light (<3 METs), moderate (3–5.9 METs), vigorous (≥6 METs) and were compared to SB at work.

Results: Out of the 1011 65-year-old subjects initially included, the 15-year follow-up has been currently completed for 688 (68%) subjects; 89 deaths (all-cause mortality, 9%) and 91 fatal and non-fatal cardiovascular and cerebrovascular events (9%), were reported. An active work (light, moderate, or vigorous intensity) was associated with a 21% reduced risk of cardiovascular (myocardial infarction) and cerebrovascular events (stroke) (OR = 0.79, 95% CI: 0.32–0.91, p < 0.02) compared to sedentary work. This relationship was already significant for light intensity work (32%; i.e., OR = 0.68, 95% CI: 0.31–0.87, p < 0.02).

Conclusion: There is strong causal evidence linking PA and SB at work with late cardiovascular and cerebrovascular disease. All in all, the risk for onset of myocardial infarction and stroke was lower among those who had a previous active work compared to those with previous sedentary work. Even previous light active work produced substantial health benefits.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT00759304.

Cumulative physical workload and mobility limitations in middle-aged men and women: a population-based study with retrospective assessment of workload

PURPOSE

To assess the association between exposure to physical workload throughout working life and risk of mobility limitations in midlife in a population-based Danish cohort.

METHODS

The study was cross-sectional with a retrospective exposure assessment, and data were from a questionnaire used in the Copenhagen Aging and Biobank. Cumulative physical workload was estimated by combining information about the participants' employments and data from a job exposure matrix. Daily amount of lifting was standardised in ton-years (lifting 1000 kg/day/year) and grouped in 5 exposure groups (no/minor (1-2 ton-years)/low (3-10 ton-years)/moderate (11-20 ton-years)/high exposure (> 20 ton-years)). The outcome was self-reports of mobility limitations (running 100 m, walking 400 m, and climbing stairs to the 2nd floor) in midlife. The association between exposure and outcome was analysed using logistic regression models.

RESULTS

We included 4996 men and 2247 women, mean age 56 years. 21% of men and 10% of women were in the highest exposure-group (> 20 ton-years). Higher cumulative exposure was associated with higher odds for mobility limitations. Exposure to more than 20 ton-years compared to no exposure increased the odds for limitations in walking, age-adjusted odds ratio (OR) 3.2 (95% CI: 2.4-4.3) for men, 2.3 (1.4-3.8) for women. Corresponding results for running: 2.5 (2.2-3.0) for men, 1.6 (1.2-2.2) for women, and for limitations in climbing stairs: 4.2 (3.3-5.2) for men, 1.7 (1.2-2.4) for women. Results were attenuated when confounders were added.

CONCLUSIONS

Exposure to physical workload throughout working life is associated with higher odds for mobility limitations in midlife.

Do highly physically active workers die early? A systematic review with meta-analysis of data from 193 696 participants

Objective

Recent evidence suggests the existence of a physical activity paradox, with beneficial health outcomes associated with leisure time physical activity, but detrimental health outcomes for those engaging in high level occupational physical activity. This is the first quantitative systematic review of evidence regarding the association between occupational physical activity and all-cause mortality.

Design

Systematic review with meta-analysis.

Data source

A literature search was performed in electronic databases PubMed, Embase, CINAHL, PsycINFO and Cochrane.

Eligibility criteria for selecting studies

We screened for peer reviewed articles from prospective studies assessing the association of occupational physical activity with all-cause mortality. A meta-analysis assessed the association of high (compared with low) level occupational physical activity with all-cause mortality, estimating pooled hazard ratios (HR) (with 95% CI).

Results

2490 unique articles were screened and 33 (from 26 studies) were included. Data from 17 studies (with 193 696 participants) were used in a meta-analysis, showing that men with high level occupational physical activity had an 18% increased risk of early mortality compared with those engaging in low level occupational physical activity (HR 1.18, 95% CI 1.05 to 1.34). No such association was observed among women, for whom instead a tendency for an inverse association was found (HR 0.90, 95% CI 0.80 to 1.01).

Conclusions

The results of this review indicate detrimental health consequences associated with high level occupational physical activity in men, even when adjusting for relevant factors (such as leisure time physical activity). These findings suggest that research and physical activity guidelines may differentiate between occupational and leisure time physical activity.

Different autonomic responses to occupational and leisure time physical activities among blue-collar workers

Purpose

The differential effect of occupational and leisure time physical activity on cardiovascular health is termed the physical activity health paradox. Cardiac autonomic modulation could bring insights about the underlying mechanism behind this differential effect. The aim was to compare heart rate variability (HRV) during different activities (sitting, standing and moving) at work and leisure among blue-collar workers.

Methods

One hundred thirty-eight workers from the NOMAD cohort were included. Data from physical activity and HRV were obtained for 3–4 days using tri-axial accelerometers (Actigraph GT3X+) and a heart rate monitor (Actiheart). HRV indices were determined during sitting, standing and moving both at work and leisure. Linear mixed-models with two fixed factors (activities and domains) were applied to investigate differences in HRV indices adjusting for individual and occupational factors.

Results

The results showed significant effects of domain (p < 0.01), physical activity type (p < 0.01) and interaction between domain and activity type (p < 0.01) on HRV indices. Mean heart rate (IBI) and parasympathetic measures of HRV (RMSSD and HF) were lower for sitting (p < 0.01) and higher for moving (p < 0.01) during work compared with leisure, while no difference between domains was found for standing (p > 0.05). Sympathovagal balance (LF/HF) was higher during work for sitting and moving (p < 0.01), but showed no difference for standing (p = 0.62).

Conclusions

Differences in cardiac autonomic modulation between work and leisure were found, indicating sympathetic predominance during work and parasympathetic predominance during leisure for sitting. Autonomic responses can be part of the mechanism that explains the differential effect of occupational and leisure time physical activity on health.

Physical activity and 22-year all-cause and coronary heart disease mortality

BACKGROUND

This study explores the effects of occupational (OPA) and leisure time physical activity (LTPA) on mortality relative to cardiorespiratory fitness and pre-existing coronary heart disease (CHD).

METHODS

Associations between OPA, measured as energy expenditure (kcal/day) and relative aerobic workload (%VO₂ max), LTPA, and 22-year mortality among 1891 Finnish men were assessed by Cox regression models stratified by CHD and adjusted for 19 confounders.

RESULTS

In fully adjusted models, each 10% of relative aerobic workload increased all-cause mortality by 13% and CHD mortality 28% (P < 0.01). Compared to healthy subjects, men with CHD experienced lower mortality risks due to OPA and higher risks due to LTPA. While LTPA had no effect among healthy men, in men with CHD each weekly hour of conditioning LTPA increased all-cause mortality risks by 10% and CHD mortality by14%.

CONCLUSION

OPA was positively associated with both all-cause and CHD mortality. LTPA was not protective. Among men with CHD, LTPA increased mortality risks.

Occupational health concerns: An analysis of physical activity of submariners

BACKGROUND

Submarine crew have low physical activity by virtue of their professional requirements. Lack of space and inadequacy of regeneration capabilities render physical activity almost impossible during deployments. However, sufficient data for physical activity levels and trends are required to measure the magnitude of inactivity.

METHODS

Data was collected from 362 personnel belonging to six submarines and one submarine base using Global Physical Activity Questionnaire. Four study groups were defined: Base, Refit, Operational/Harbour and Operational/Sea.

RESULTS

Overall, 30.11% of the crew had insufficient physical activity (4.04% in Base, 5.75% in Refit, 15% in Ops/Harbour and 91.67% in Ops/Sea groups). Of the total physical activity, 48.7% was contributed by activity at work, 18.71% by travel related activity and 32.62% by recreational physical activity. Base group recorded the highest recreational activity of 1468.28 Minutes-per-Week. Recreational activity contributed 43.22% to total physical activity for this group. Mean total physical activity was highest for ≥45 years and lowest for ≤24 years. ≥45 years old also recorded the highest recreational activity.

CONCLUSION

The greatest cause for concern comes from the crew in operational submarines and the younger crew. Physical activity profile of the crew when at sea cannot be changed and greater research is required to assess the long-term health effects of physical inactivity in this group. However, what can be modified are the work schedules for refit submarines and operational submarines when in harbour. Targeted interventions and strategies are required to establish sustainable behaviour patterns with regards to physical activity in these groups.

Does influence at work modify the relation between high occupational physical activity and risk of heart disease in women?

PURPOSE

To investigate whether influence at work modifies the association between demanding and strenuous occupational physical activity (OPA) and risk of ischaemic heart disease (IHD).

METHODS

A sample of 12,093 nurses aged 45-64 years from the Danish Nurse Cohort Study was followed for 20.6 years by individual linkage to incident IHD in the Danish National Patient Registry. Information on OPA, influence at work, other occupational factors and known risk factors for IHD was collected by self-report in 1993.

RESULTS

During follow-up 869 nurses were hospitalised with incident IHD. Nurses exposed to strenuous OPA and low influence at work had a 46% increased risk of IHD [hazard ratio (HR) 1.46 (95% confidence interval (CI) 1.02-2.09)] compared to the reference group of nurses with moderate OPA and high influence at work. Nurses exposed to strenuous OPA and high influence at work were not at an increased risk of IHD [HR 1.10 (95% CI 0.59-2.06)]. An additive hazards model showed there were 18.0 (95% CI -0.01 to 36.0) additional cases of IHD per 10,000 person years among nurses with strenuous OPA and low influence at work compared to nurses with moderate OPA and high influence at work. A detrimental additive interaction between strenuous OPA and low influence at work that could explain the additional cases of IHD among nurses with strenuous OPA and low influence at work was indicated.

CONCLUSION

The findings suggest that high influence at work may buffer some of the adverse effects of strenuous OPA on risk of IHD.

Do psychosocial job resources buffer the relation between physical work demands and coronary heart disease? A prospective study among men

PURPOSE

Increasing evidence shows the detrimental impact of high physical work demands for cardiovascular health and mortality. The aim of this study was to investigate the buffering effects of social support at work and job control in the relation between physical work demands and incidence of coronary events.

METHODS

The study included 14,337 middle-aged men free from coronary heart disease (CHD) at baseline. The sample consisted of a mixed occupational group recruited within 18 organizations from the manufacturing, service, and public sector. Data were collected through standardized questionnaires and clinical examinations. The incidence of clinical coronary events was monitored during a mean follow-up time of 3.15 years. Multilevel Cox proportional hazard regression modeling was used, adjusting for socio-demographic and classical coronary risk factors.

RESULTS

Social support at work buffered the impact of physical work demands on CHD risk: Only among workers with low social support at work did physical work demands significantly increase the risk for CHD incidence (fully adjusted HR 2.50: 95 % CI 1.13-5.50), while this harmful effect completely disappeared in case of high level of workplace social support (fully adjusted HR 0.40; 95 % CI 0.09-1.70). No interaction or buffering effect with job control was observed.

CONCLUSIONS

The results of our study suggest that supportive relationships at work may be a useful resource for reducing the cardiovascular risk associated with physical work demands in men. Future studies are needed to confirm this moderating role of workplace social support and to unravel the underlying mechanisms.

Working postures and physical activity among registered nurses

Nurses report a high prevalence of musculoskeletal discomfort, particularly of the low back and neck/shoulder. This study characterized the full-shift upper arm and trunk postures and movement velocities of registered nurses using inertial measurement units (IMUs). Intensity of occupational physical activity (PA) was also ascertained using a waist-worn PA monitor and using the raw acceleration data from each IMU. Results indicated that nurses spent a relatively small proportion of their work time with the arms or trunk in extreme postures, but had few opportunities for rest and recovery in comparison to several other occupational groups. Comparisons between nurses in different PA groups suggested that using a combination of accelerometers secured to several body locations may provide more representative estimates of physical demands than a single, waist-worn PA monitor. The findings indicate a need for continued field-based research with larger sample sizes to facilitate the development of maximally effective intervention strategies.

Work, household, and leisure-time physical activity and risk of mortality in the EPIC-Spain cohort

OBJECTIVE

Large-scale longitudinal data on the association of domain-specific physical activity (PA) and mortality is limited. Our objective was to evaluate the association of work, household (HPA), and leisure time PA (LTPA) with overall and cause-specific mortality in the EPIC-Spain study.

METHODS

38,379 participants (62.4% women), 30-65years old, and free of chronic disease at baseline were followed-up from recruitment (1992 - 1996) to December 31st, 2008 to ascertain vital status and cause of death. PA was evaluated at baseline and at a 3-year follow-up with a validated questionnaire (EPIC-PAQ) and combined variables were used to classify the participants by sub-domains of PA. Associations with overall, cancer, and cardiovascular mortality risks were assessed using competing risk Cox regression models adjusted by potential confounders.

RESULTS

After 13.6years of mean follow-up, 1371 deaths were available for analyses. HPA was strongly associated to reduced overall (hazard ratio (HR) for Q4 vs. Q1=0.47 (0.34, 0.64)) and cause-specific mortalities in women and to lower cancer mortality in men (P for trend=0.004), irrespective of age, education, and lifestyle and morbidity variables. LTPA was associated with lower mortality in women (HR for Q4 vs. Q1=0.71 (0.52, 0.98)), but not men. No relationships were found between sedentariness at work and overall mortality.

CONCLUSIONS

HPA was associated to lower mortality risk in men and women from the EPIC-Spain cohort, whereas LTPA also contributed to reduce risk of death in women. Considering the large proportion of total daily PA that HPA represents in some population groups, these results are of public health importance.

Evaluation of four sensor locations for physical activity assessment

Direct measurements of physical activity (PA) obtained with inertial measurement units (IMUs) secured to the upper arms and trunk of 36 registered nurses working a full shift were compared to measurements obtained with a commercially-available PA monitor (ActiGraph wGT3X-BT) worn at the waist. Raw accelerations from each device were summarized into PA counts/min and metabolic equivalent (METs) categories using standard definitions. Differences between measurements were examined using repeated measures one-way analyses of variance (ANOVA) and agreement was assessed using Bland-Altman plots. Statistically significant differences were observed between all sensor locations for all PA summary metrics except for between the left and right arm for percentages of work time in the light and moderate counts/min categories. Bland-Altman plots suggested limited agreement between measurements obtained with the IMUs and measurements obtained with the wGT3X-BT waist-worn PA monitor. Results indicate that PA measurements vary substantially based on sensor location.

Are hypertensive women at additional risk of ischaemic heart disease from physically demanding work?

BACKGROUND

The combination of hypertension and high physical activity at work may increase blood pressure considerably and increase the risk of atherosclerosis and thereby ischaemic heart disease (IHD), but only a few studies in men, and none among women, have examined this topic.

DESIGN

This was a prospective cohort study.

METHODS

In 1993, 12,093 female nurses from the Danish Nurse Cohort Study, aged 45-64 years answered a baseline questionnaire on physical activity at work, history of hypertension, a selection of known risk factors for IHD and occupational factors. Information on incident IHD from baseline to 2008 was retrieved by individual linkage to the National Register of Hospital Discharges.

RESULTS

In a fully adjusted Cox model, hypertensive nurses with high physical activity at work had nearly three times higher risk of IHD (hazard ratio (HR) 2.87 (95% confidence interval (CI) 2.12-3.87)) compared to normotensive nurses with moderate physical activity at work. Significant additive interaction between physical activity at work and hypertension was found measured by the relative excess risk due to additive interaction (RERI) (1.20 (95% CI 0.26-2.14), and in an additive hazards model. Hypertensive nurses with high physical activity at work had 60 additional cases of IHD per 10,000 person years compared to normotensive nurses with moderate physical activity at work (60.0 (95% CI 38.1-81.9; p < 0.001)), of which more than half was explained by additive interaction (40.7 (95% CI 11.7-69.7; p = 0.006)). No multiplicative interaction (p = 0.249) was found.

CONCLUSIONS

This study among Danish nurses indicated that hypertensive women may be at particular high risk of IHD from physically demanding work.

Analysis of work ability and work-related physical activity of employees in a medium-sized business

Background

Work-related physical activity (PA) and work ability are of growing importance in modern working society. There is evidence for age- and job-related differences regarding PA and work ability. This study analyses work ability and work-related PA of employees in a medium-sized business regarding age and occupation.

Methods

The total sample consists of 148 employees (116 men—78.38 % of the sample—and 32 women, accounting for 21.62 %; mean age: 40.85 ± 10.07 years). 100 subjects (67.57 %) are white-collar workers (WC), and 48 (32.43 %) are blue-collar workers (BC). Work ability is measured using the work ability index, and physical activity is obtained via the Global Physical Activity Questionnaire.

Results

Work ability shows significant differences regarding occupation (p = 0.001) but not regarding age. Further, significant differences are found for work-related PA concerning occupation (p < 0.0001), but again not for age. Overall, more than half of all subjects meet the current guidelines for physical activity.

Conclusion

Work ability is rated as good, yet, a special focus should lie on the promotion during early and late working life. Also, there is still a lack of evidence on the level of work-related PA. Considering work-related PA could add to meeting current activity recommendations.

Physical activity levels at work and outside of work among commercial construction workers

OBJECTIVE

Characterize the number of minutes of moderate and vigorous physical activities at work and outside of work during seven consecutive days, in a sample of 55 commercial construction workers.

METHODS

Workers wore accelerometers during work and outside-of-work hours for seven consecutive days and completed brief survey at the seventh day of data collection.

RESULTS

From the directly measured physical activity, the average number per participant of moderate minutes of occupational physical activity and physical activity outside of work obtained in short bouts were 243 minutes (65%) and 130 minutes (35%), respectively. Directly measured minutes of vigorous occupational physical activity were significant and positively correlated with self-reported fatigue.

CONCLUSIONS

Among commercial construction workers, physical activity from work contributes significantly, approximately two thirds, toward a worker's total amount of weekly minutes of moderate physical activity.

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.

Is aerobic workload positively related to ambulatory blood pressure? A cross-sectional field study among cleaners

PURPOSE

Cardiovascular disease is prevalent among workers with high levels of occupational physical activity. The increased risk may be due to a high relative aerobic workload, possibly leading to increased blood pressure. However, studies investigating the relation between relative aerobic workload and ambulatory blood pressure (ABP) are lacking. The aim was to explore the relationship between objectively measured relative aerobic workload and ABP.

METHODS

A total of 116 cleaners aged 18-65 years were included after informed consent was obtained. A portable device (Spacelabs 90217) was mounted for 24-h measurements of ABP, and an Actiheart was mounted for 24-h heart rate measurements to calculate relative aerobic workload as percentage of relative heart rate reserve. A repeated-measure multi-adjusted mixed model was applied for analysis.

RESULTS

A fully adjusted mixed model of measurements throughout the day showed significant positive relations (p < 0.001): a 1% increase in mean relative aerobic workload was associated with an increase of 0.42 ± 0.05 mmHg (95% CI 0.32-0.52 mmHg) in systolic ABP and 0.30 ± 0.04 mmHg (95% CI 0.22-0.38 mmHg) in diastolic ABP. Correlations between relative aerobic workload and ABP were significant.

CONCLUSIONS

Because workers may have an elevated relative aerobic workload for several hours each working day, this relationship may elucidate a mechanism behind the increased risk for cardiovascular disease among workers exposed to high levels of occupational physical activity.

Aerobic exercise reduces biomarkers related to cardiovascular risk among cleaners: effects of a worksite intervention RCT

Purpose

Blue-collar workers have an increased risk of cardiovascular disease. Accordingly, elevated levels of biomarkers related to risk of cardiovascular disease, such as high-sensitive C-reactive protein, have been observed among blue-collar workers. The objective was to examine whether an aerobic exercise worksite intervention changes the level of inflammation biomarkers among cleaners.

Methods

The design was a cluster-randomized controlled trial with 4-month worksite intervention. Before the 116 cleaners aged 18–65 years were randomized, they signed an informed consent form. The reference group (n = 59) received lectures, and the aerobic exercise group (n = 57) performed worksite aerobic exercise (30 min twice a week). Levels of biomarkers (high-sensitive C-reactive protein, fibrinogen, cholesterol, low- and high-density lipoprotein cholesterol and triglyceride) were collected at baseline and after 4 months. A repeated-measure, multi-adjusted, mixed-model intention-to-treat analysis was applied to compare between-group differences. The study was registered as ISRCTN86682076.

Results

Significant (p < 0.05) between-group reductions from baseline to follow-up were found for high-sensitive C-reactive protein (−0.54 ± 0.20 µg/ml; 95 % CI −0.94, −0.14), low-density lipoprotein cholesterol (−0.32 ± 0.11 mmol/L; 95 % CI −0.54, −0.10) and the ratios of LDL/HDL (−0.30 ± 0.08; 95 % CI −0.46, −0.14), and LDL/TC cholesterol (−0.04 ± 0.02; 95 % CI −0.07, −0.01).

Conclusion

This study indicates that an aerobic exercise intervention among cleaners leads to reduced levels of high-sensitive C-reactive protein and low-density lipoprotein cholesterol, and an unaltered level of fibrinogen. The aerobic exercise seems to improve inflammatory levels and lipoprotein profile among cleaners, with no signs of cardiovascular overload.

Occupational noise and myocardial infarction: considerations on the interrelation of noise with job demands

The present analysis aims to differentiate the association of noise on myocardial infarction (MI) by job specific demands using International Standard Classification of Occupations (ISCO)-88 codes as a proxy. Data of a German case-control study were supplemented by job descriptions (indicated by ISCO-88). It was examined whether the demands in the various occupational groups modify the effect of noise. Noise and occupational groups are combined to form new exposure categories. Conditional logistic regression models were fitted to identify effects of combined job-noise categories. For the highest noise range (95-124 dB(A)) we found a significant odds-ratio (OR) of 2.18 (confidence interval [CI]_0.95 = 1.17-4.05) independent of the profession. Some interesting results were found indicating ISCO groups with possible risk. In men, noticeable effects for the exposure category between 62 dB(A) and 84 dB(A) are calculated in the group of legislators and senior officials (ISCO-group 11; OR=1.93; CI_0.95 = 0.50-7.42), the group consisting of life science and health professionals (ISCO-group 22; OR=2.18; CI_0.95 = 0.36-13.1), the group of life science and health associate professionals (ISCO-group 32; OR = 2.03; CI_0.95 = 0.50-8.24), and the group of “precision, handicraft, printing, and related trades workers” (ISCO-group 73; OR = 2.67; CI_0.95 = 0.54-13.0). In the exposure range of 85-94 dB(A), high ORs are calculated for “skilled agricultural, fishery, and forestry workers” (ISCO-group 6; OR = 4.31; CI_0.95 = 0.56-33.3). In women, there are high (nonsignificant) ORs in ISCO-group 1 (OR = 2.43; CI_0.95 = 0.12-50.0), ISCO-group 2 (OR = 1.80; CI_0.95 = 0.31-10.5), and ISCO-group 9 (OR = 2.45; CI_0.95 = 0.63-9.51) for a noise exposure between 62 dB(A) and 84 dB(A). When investigating noise at the workplace in relation to cardiovascular diseases it is important to take the specific requirements of a job into account. Thus, work tasks with high health risks can be identified that helps to develop appropriate prevention strategies.

Combined association of occupational and leisure-time physical activity with all-cause and coronary heart disease mortality among a cohort of men followed-up for 22 years

OBJECTIVES

Leisure-time physical activity (LTPA) is a well-established protective factor for all-cause mortality and cardiovascular mortality while occupational physical activity (OPA) has shown contradictory results. We examined the association between OPA and all-cause and coronary heart disease (CHD) mortality, and tested its combined effect with LTPA.

METHODS

The CORDIS Study (Cardiovascular Occupational Risk Factor Determination in Israel Study) is a prospective cohort study of industrial workers examined during 1985-1989 and followed-up for 22 years. Data on self-reported OPA and LTPA among 4819 males (20-70 years old) were merged with data on all-cause and CHD mortality obtained from the National Death Registry.

RESULTS

A higher incidence rate of all-cause mortality and CHD mortality was observed among men who performed moderate-hard OPA compared with those who performed none-mild OPA. Multiple regression analysis based on the Cox proportional hazards model showed that moderate-hard OPA was associated with increased risk of all-cause mortality (HR=1.42, 95% CI 1.16 to 1.74, p<0.001), while LTPA (30 min at least twice a week vs less or none) was associated with reduced risk for all-cause mortality (HR=0.61, 95% CI 0.48 to 0.79, p<0.001), after adjusting for potential confounders, including sociodemographic variables, body mass index, comorbidity and lifestyle habits. Employees who performed moderate-hard OPA and no LTPA had the greatest risk for all-cause mortality and employees who performed none-light OPA and LTPA had the lowest risk. Similar but non-significant trends were observed for the association with CHD mortality.

CONCLUSIONS

Moderate-hard OPA among industrial male workers may be deleterious to health and should not be a substitute to LTPA.

Validity of the Acti4 method for detection of physical activity types in free-living settings: comparison with video analysis

This study examined the ability of the Acti4 software for identifying physical activity types from accelerometers during free-living with different levels of movement complexity compared with video observations. Nineteen aircraft cabin cleaners with ActiGraph GT3X+ accelerometer at the thigh and hip performed one semi-standardised and two non-standardised sessions (outside and inside aircraft) with different levels of movement complexity during working hours. The sensitivity for identifying different activity types was 75.4-99.4% for the semi-standardised session, 54.6-98.5% outside the aircraft and 49.9-90.2% inside the aircraft. The specificity was above 90% for all activities, except 'moving' inside the aircraft. These findings indicate that Acti4 provides good estimates of time spent in different activity types during semi-standardised conditions, and for sitting, standing and walking during non-standardised conditions with normal level of movement complexity. The Acti4 software may be a useful tool for researchers and practitioners in the field of ergonomics, occupational and public health. Practitioner Summary: Being inexpensive, small, water-resistant and without wires, the ActiGraph GT3X+ by applying the Acti4 software may be a useful tool for long-term field measurements of physical activity types for researchers and practitioners in the field of ergonomics, occupational and public health.

High occupational physical activity and risk of ischaemic heart disease in women: the interplay with physical activity during leisure time

BACKGROUND

Recent studies indicate that physically demanding work is a risk factor for heart disease among men, especially those with low or moderate physical activity during leisure time. Among women, present evidence is inconclusive.

DESIGN

The design was a prospective cohort study.

METHODS

This investigation in the Danish Nurse Cohort Study included 12,093 female nurses aged 45-64 years, who answered a self-report questionnaire on physical activity at work and during leisure time, known risk factors for ischaemic heart disease (IHD) and occupational factors at baseline in 1993. Information on the 15-year incidence of IHD was obtained by individual linkage in the National Register of Hospital Discharges to 2008.

RESULTS

During follow-up 580 participants were hospitalised with IHD. A significant interaction between occupational and leisure time physical activity was found with the lowest risk of IHD among nurses with the combination of moderate physical activity at work and vigorous physical activity during leisure time. Compared to this group high physical activity at work was associated with a higher risk of IHD at all levels of physical activity during leisure time increasing from hazard ratio 1.75 (95% confidence interval (CI) 1.10-2.80) among nurses with vigorous physical activity during leisure time to 2.65 (95% CI 1.44-4.88) among nurses being sedentary during leisure time.

CONCLUSIONS

This study among Danish nurses suggests that high physical activity at work is a risk factor for IHD among women. Vigorous physical activity during leisure time lowered but did not completely counteract the adverse effect of occupational physical activity on risk of IHD.

Heavy lifting at work and risk of ischemic heart disease: protocol for a register-based prospective cohort study

BACKGROUND

There are theoretical grounds to suspect that heavy lifting at work is an important risk factor for ischemic heart disease (IHD). However the relationship has not been sufficiently acknowledged by empirical studies. Positive and statistically significant associations have been found in studies that utilize self-reported exposure data. Such studies are, however, prone to reporting bias. All else equal, people with a poor cardiovascular fitness/health may have a higher propensity to perceive their work environment as heavy.

OBJECTIVE

The study described in the present protocol aims to investigate the relationship between heavy lifting at work and IHD by use of material and methods that are free from reporting bias.

METHODS

This is a register-based prospective cohort study. Male blue-collar workers in Denmark will be identified and followed through national registers, from 2001-2010, for hospital treatment or death due to IHD. Relative rates of IHD between "workers in occupations likely to involve heavy lifting" and "other blue-collar workers" will be estimated through Poisson regression.

RESULTS

Results are expected to be ready in mid-2015.

CONCLUSIONS

Since this is not a randomized study, it cannot confirm etiological hypotheses. It may, however, confirm that employment in occupations that involve heavy lifting is a predictor for IHD and thereby lend support to the hypothesis of a causal relationship.

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

OBJECTIVES

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

DESIGN

Prospective population-based follow-up.

SETTING

Municipalities in Finland.

PARTICIPANTS

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

MEASUREMENTS

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

RESULTS

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

CONCLUSION

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

The combined relationship of occupational and leisure-time physical activity with all-cause mortality among men, accounting for physical fitness

The aim of this study was to assess the combined relationship of occupational physical activity and leisure-time physical activity with all-cause mortality among men, while accounting for physical fitness. The prospective Belgian Physical Fitness Study included 1,456 male workers aged 40-55 years who were free of coronary heart disease at baseline. Baseline data were collected through questionnaires and clinical examinations from 1976 to 1978. To estimate physical fitness, a submaximal graded exercise test was performed on a bicycle ergometer. Total mortality was registered during a mean follow-up period of 16.9 years. Main results were obtained through Cox proportional hazards regression analysis. A total of 145 deaths were registered during follow-up. After adjustment for confounders, a significantly increased mortality rate was observed in workers who had low levels of both physical activity types (hazard ratio = 2.07, 95% confidence interval: 1.03, 4.19) but also in workers combining high occupational physical activity and low leisure-time physical activity (hazard ratio = 2.04, 95% confidence interval: 1.07, 3.91); the latter finding was particularly pronounced among workers with a low physical fitness level. The present results confirm the existence of a complex interplay among different physical activity settings and fitness levels in predicting mortality.

The association between leisure time physical activity and coronary heart disease among men with different physical work demands: a prospective cohort study

The interplay of occupational and leisure time physical activity (LTPA) in affecting cardiovascular health is subject to debate. This study aimed to examine the independent and interacting associations of leisure time and occupational physical activity (OPA) with the incidence of coronary events within the BELSTRESS cohort. The study included 14,337 middle-aged men free from coronary heart disease at baseline. Standardized questionnaires and clinical examinations were used to assess socio-demographic factors, level of physical activity, job strain and classical coronary risk factors. The incidence of clinical coronary events was monitored during a mean follow-up time of 3.15 years. Results demonstrated overall a beneficial relation of LTPA and an adverse relation of physical work demands with cardiovascular health. However, an interaction effect between both physical activity types was observed, showing that men with high physical job demands who also engaged in physical activity during leisure time had an almost four times increased incidence of coronary events after adjusting for socio-demographic and classical coronary risk factors (HR 3.82; 95% CI 1.41-10.36). Stratified analyses revealed that moderate to high physical activity during leisure time was associated with a 60% reduced incidence rate of coronary events in men with low OPA (age adjusted HR 0.40; 95% CI 0.21-0.76), while this protective association was not observed in workers being exposed to high physical work demands (age adjusted HR 1.67; 95% CI 0.63-4.48). These findings suggest that recommendations regarding LTPA should be tailored according to the level of occupational physical activity.