Occupational heavy lifting and risk of ischemic heart disease and all-cause mortality

Leisure-time and occupational physical activity and risk of cardiovascular disease incidence: a systematic-review and dose-response meta-analysis of prospective cohort studies

BACKGROUND AND OBJECTIVE

Physical activity has benefits for the cardiovascular system, however, what levels and types of activity provide optimal cardiovascular health is unclear. We aimed to determine the level of physical activity that has the most benefits against cardiovascular diseases (CVD).

METHODS

PubMed, Scopus, and Web of Science were searched for prospective cohort studies on leisure-time (LTPA) or occupational physical activity (OPA) as the exposure and major types of CVD (total CVD, coronary heart disease [CHD], stroke, and atrial fibrillation [AF]) incidence as the outcome. Risk of bias of studies was evaluated using the ROBINS-I tool. Summary hazard ratios (HR) were calculated using random-effects pairwise model.

RESULTS

A total of 103 studies were included in the analysis. The highest versus the lowest LTPA was associated with a lower risk of overall CVD (HR = 0.81; 95% CI: 0.77-0.86), CHD (HR = 0.83; 0.79-0.88), and stroke (HR = 0.83; 0.79-0.88), but not AF (HR = 0.98; 0.92-1.05). Linear dose-response analyses showed a 10%, 12%, 9%, and 8% risk reduction in CVD, CHD, stroke, and AF incidence, respectively, for every 20 MET-hours/week increase in LTPA. In nonlinear dose-response analyses, there were inverse associations up to 20 MET-hours/week with 19% and 20% reduction in CVD and CHD risk, and up to 25 MET-hours/week with 22% reduction in stroke, with no further risk reduction at higher LTPA levels. For AF, there was a U-shaped nonlinear association with the maximum 8% risk reduction at 10 MET-hours/week of LTPA. Higher levels of OPA were not associated with risk of CVD, CHD, stroke, or AF.

CONCLUSIONS

Overall, results showed an inverse dose-response relationship between LTPA and risk of CVD, CHD, stroke, and AF. Running was the most beneficial LTPA but the risk was similar among various LTPA intensities. OPA showed no benefits in total or any type of CVD.

Relationships of Total and Domain-Specific Moderate-to-Vigorous Physical Activity with All-Cause and Disease-Specific Mortality

PURPOSE

This study aimed to investigate the relationships of moderate-to-vigorous physical activity (MVPA) with all-cause and disease-specific mortality. We also investigated how the association between MVPA at leisure time (LT-MVPA) and health outcomes differs at different MVPA at work (WT-MVPA) levels.

METHODS

The 81,601 community-dwelling Japanese persons age 50-79 yr who responded to a questionnaire in 2000-2003 were followed until 2018. Cox proportional hazard model was used to examine the association of total MVPA with risks of all-cause, cancer, heart disease, stroke, and respiratory disease mortality. Then, we compared the mortality risk according to the tertile of LT-MVPA, stratified by the tertile of WT-MVPA.

RESULTS

During the 15.1 yr of average follow-up, 16,951 deaths were identified. Even total MVPA below the recommended volume (i.e., 0.1-1.49 MET·h·d -1 ) was associated with 11% to 24% reductions in all-cause (hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.82-0.96) and heart disease mortality (HR, 0.76; 95% CI, 0.61-0.94), compared with no MVPA at all. The further reduced risks were seen in MVPA up to 10 MET·h·d -1 . The inverse association between LT-MVPA and mortality risks was more evident at lower WT-MVPA, which was also inversely associated with the risks.

CONCLUSIONS

Health benefits were observed at low levels of MVPA and up to 10 MET·h·d -1 , although the fine threshold for excessive MVPA was not clear. LT-MVPA had distinct health benefits especially for persons with lower WT-MVPA.

Occupational physical activity, all-cause mortality and incidence of cardiovascular diseases: results from three Italian cohorts

PURPOSE

To examine the association of exposure to Occupational Physical Activity (OPA) with all-cause mortality and incidence of cardiovascular diseases (CVD).

METHODS

The study population was composed of three Italian cohorts: a national cohort of employees participating in the National Health Survey 2005, followed-up until 2014 (ILS 2005), and two urban cohorts of employees resident in Turin at 2001 and 2011 censuses (TLS 2001 and TLS 2011, respectively), both followed-up until 2018. Follow-up was conducted through individual record-linkage with death registries and hospital admissions archives. Exposure to OPA was assigned through an Italian job-exposure matrix (JEM). Relative Risks of both CVD incidence and overall mortality associated with OPA quartiles (IRR) were estimated using Poisson regression models adjusted for socio-demographics and health, and in the national cohort, also for leisure time physical activity, BMI, smoking, diabetes, and hypertension.

RESULTS

Compared to the lowest quartile, the highest OPA quartile was associated in both genders with significantly increased mortality in TLS 2001 (IRR = 1.11 among men, IRR = 1.20 among women) and in TLS 2011 (IRR = 1.27 among men and IRR = 1.73 among women), whereas in the ILS 2005 cohort no association was found. Among women, high OPA was also associated with CVD risk in TLS 2001 and 2011 (IRR = 1.39 and IRR = 1.16 for the highest quartile, respectively), while in the ILS cohort in both genders only the third quartile showed a significantly higher risk.

CONCLUSION

Our results indicate that OPA does not have a beneficial effect on CVD and mortality, but rather suggest that it may produce deleterious health effects.

Differences in lumbar spine intradiscal pressure between standing and sitting postures: a comprehensive literature review

Background

Musculoskeletal disorders (MSDs), especially in the lumbar spine, are a leading concern in occupational health. Work activities associated with excessive exposure are a source of risk for MSDs. The optimal design of workplaces requires changes in both sitting and standing postures. In order to secure such a design scientifically proved quantitative data are needed that would allow for the assessment of differences in spine load due to body posture and/or exerted force. Intradiscal pressure (IP) measurement in the lumbar spine is the most direct method of estimating spinal loads. Hence, this study aims at the quantitative evaluation of differences in lumbar spine load due to body posture and exerted forces, based on IP reported in publications obtained from a comprehensive review of the available literature.

Methodology

In order to collect data from studies measuring IP in the lumbar spine, three databases were searched. Studies with IP for living adults, measured in various sitting and standing postures, where one of these was standing upright, were included in the analysis. For data to be comparable between studies, the IP for each position was referenced to upright standing. Where different studies presented IP for the same postures, those relative IPs (rIP) were merged. Then, an analysis of the respective outcomes was conducted to find the possible relationship of IPs dependent on a specific posture.

Results

A preliminary analysis of the reviewed papers returned nine items fulfilling the inclusion and exclusion criteria. After merging relative IPs from different studies, rIP for 27 sitting and 26 standing postures was yielded. Some of the data were useful for deriving mathematical equations expressing rIP as a function of back flexion angle and exerted force in the form of a second degree polynomial equation for the standing and sitting positions. The equations showed that for the standing posture, the increase in IP with increasing back flexion angle is steeper when applying an external force than when maintaining body position only. In a sitting position with the back flexed at 20°, adding 10 kg to each hand increases the IP by about 50%. According to the equations developed, for back flexion angles less than 20°, the IP is greater in sitting than in standing. When the angle is greater than 20°, the IP in the sitting position is less than in the standing position at the same angle of back flexion.

Conclusions

Analysis of the data from the reviewed papers showed that: sitting without support increases IP by about 30% in relation to upright standing; a polynomial of the second degree defines changes in IP as a function of back flexion for for both postures. There are differences in the pattern of changes in IP with a back flexion angle between sitting and standing postures, as back flexion in standing increases IP more than in sitting.

Health needs of migrant female head porters in Ghana: evidence from the Greater Accra and Greater Kumasi Metropolitan areas

BACKGROUND

In low-and middle-income countries, migrants are confronted with health needs which affect the promotion of their well-being and healthy lives. However, not much is known about the health needs of migrant female head porters (Kayayei) in Ghana. This study assesses the health needs of migrant female head porters in the Greater Kumasi Metropolitan Area (GKMA) and Greater Accra Metropolitan Area (GAMA).

METHODS

The study adopted a convergent mixed methods design where both qualitative and quantitative data were used. A representative sample size of 470 migrant female head porters was used for the study.

RESULTS

The study revealed that ante-natal care, post-natal care, treatment of malaria, treatment of diarrhoea diseases, mental health, sexual health, and cervical cancer were health needs of migrant female head porters. The findings showed that participants from the GAMA significantly have greater cervical cancer needs (71.6% vrs 67.1%, p = 0.001) compared to those from the GKMA. Kayeyei from the GKMA significantly have greater mental health needs than those from the GAMA (84.6% vrs 79.2%, p = 0.031). Also, Kayeyei from the GKMA significantly have higher attendance of post-natal care compared to those from the GAMA (99.4% vrs 96.2%, p = 0.013).

CONCLUSION

The findings underscore differential health needs across geographical localities. Based on the findings of the study, specific health needs such as ante-natal care and post-natal care should be included in any health programmes and policies that aim at addressing health needs of migrant female head porters in the two metropolitan areas of Ghana.

Assessment of cardiovascular load among hotel room cleaners

Hotel room cleaners are a vulnerable population at risk for cardiovascular disease. To evaluate their workload heart rate (HR), % heart rate reserve (%HRR), blood pressure (BP), metabolic equivalent (MET), and energy expenditure (EE) were measured over two workdays and two off-workdays. The mean age was 45.5 (SD 8.2) years with a mean 10.4 (SD 7.8) years of work experience. Mean average and peak HR, %HRR, MET, and EE were significantly higher during a workday than an off-workday for the entire work shift, first and last hour of work. Mean average HR and %HRR saw the largest increase between the lunch and post-lunch interim. One-fourth of subjects exceeded the recommended 30% HRR threshold for 8-hour shifts. Some workers experienced a substantial increase in HR and DBP over a workday indicating physiologic fatigue and thus may be at increased risk for cardiovascular disease and premature death due to excessive physical work demands.

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.

Disability pensions related to heavy physical workload: a cohort study of middle-aged and older workers in Sweden

OBJECTIVES

The aim of the study was to examine the associations between heavy physical workload among middle-aged and older workers and disability pension due to any diagnosis, as well as musculoskeletal, psychiatric, cardiovascular or respiratory diagnoses. The population-based design made it possible to examine dose-response and potential gender differences in the associations.

METHODS

About 1.8 million men and women aged 44-63 years and registered as living in Sweden in 2005 were followed regarding disability pension during 2006-2016, until ages 55-65 years. Mean values of physical workload and job control, estimated through gender-specific job-exposure matrices (JEMs), were assigned to individuals through their occupational titles in 2005. Exposure values were ranked separately for women and men and divided into quintiles. Associations were analyzed with Cox proportional-hazards regression.

RESULTS

The analyses showed robust, dose-response associations between physical workload and disability pension with a musculoskeletal diagnosis in both genders: the adjusted hazard ratio and 95% confidence interval for those with the heaviest exposure was 2.58 (2.37-2.81) in women and 3.34 (2.83-3.94) in men. Dose-response associations were also seen in relation to disability pension with a cardiovascular or a respiratory diagnosis, though the hazard ratios were smaller. Physical workload was not associated with disability pension with a psychiatric diagnosis after adjustment for job control.

CONCLUSION

This study of the entire Swedish population of middle-aged and older workers suggests that higher degrees of physical workload may increase the risk of disability pension overall, and specifically with musculoskeletal, cardiovascular or respiratory diagnosis, in both women and men.

Ischaemic Heart Disease and Occupational Exposures: A Longitudinal Linkage Study in the General and Māori Populations of New Zealand

OBJECTIVES

This study assessed associations between occupational exposures and ischaemic heart disease (IHD) for males and females in the general and Māori populations (indigenous people of New Zealand).

METHODS

Two surveys of the general adult [New Zealand Workforce Survey (NZWS); 2004-2006; n = 3003] and Māori population (Māori NZWS; 2009-2010; n = 2107), with information on occupational exposures, were linked with administrative health data and followed-up until December 2018. Cox proportional hazards regression (adjusted for age, deprivation, and smoking) was used to assess associations between organizational factors, stress, and dust, chemical and physical exposures, and IHD.

RESULTS

Dust [hazard ratio (HR) 1.6, 95%CI 1.1-2.4], smoke or fumes (HR 1.5, 1.0-2.3), and oils and solvents (HR 1.5, 1.0-2.3) were associated with IHD in NZWS males. A high frequency of awkward or tiring hand positions was associated with IHD in both males and females of the NZWS (HRs 1.8, 1.1-2.8 and 2.4, 1.1-5.0, respectively). Repetitive tasks and working at very high speed were associated with IHD among NZWS females (HRs 3.4, 1.1-10.4 and 2.6, 1.2-5.5, respectively). Māori NZWS females working with vibrating tools and those exposed to a high frequency of loud noise were more likely to experience IHD (HRs 2.3, 1.1-4.8 and 2.1, 1.0-4.4, respectively). Exposure to multiple dust and chemical factors was associated with IHD in the NZWS males, as was exposure to multiple physical factors in males and females of the NZWS.

CONCLUSIONS

Exposures associated with an elevated IHD risk included dust, smoke or fumes, oils and solvents, awkward grip or hand movements, carrying out repetitive tasks, working at very high speed, loud noise, and working with tools that vibrate. Results were not consistently observed for males and females and between the general and Māori populations.

Is occupational physical activity associated with mortality in UK Biobank?

BACKGROUND

Current physical activity guidelines do not distinguish between activity accumulated in different behavioural domains but some studies suggest that occupational physical activity (OPA) may not confer health benefits and could even be detrimental. The purpose of this study was to investigate associations between OPA and mortality outcomes.

METHODS

From baseline (2006-2010), 460,901 UK Biobank participants (aged 40-69 years) were followed for a median 12.0 (IQR: 11.3-12.7) years. OPA was categorised by cross-tabulating degree of manual work and walking/standing work amongst those in paid employment (n = 267,765), and combined with categories of occupational status for those not in paid employment (n = 193,136). Cox proportional hazards models were used to estimate sex-stratified hazard ratios (HR) and 95% confidence intervals (CI) for mortality from all causes, CVD, and cancer by occupational group, and for working hours/week and non-occupational physical activity stratified by occupational group. Models included adjustment for age and a range of lifestyle, socio-economic and health-related covariates.

RESULTS

During 5,449,989 person-years of follow-up, 28,740 deaths occurred. Compared to those reporting no heavy manual or walking/standing work (e.g. sedentary office workers) and adjusting for covariates, retirement was associated with lower mortality in women (HR = 0.62, CI: 0.53-0.72) and men (HR = 0.80, CI: 0.71-0.90), whereas unemployment was associated with higher mortality in men only (HR = 1.24, CI: 1.07-1.45). Within the working population, there was no evidence of differences in all-cause, CVD or cancer mortality by OPA group when comparing those reporting higher levels of OPA to the lowest OPA reference group for both women and men. Working < 35 h/week versus 35-40 h/week was associated with lower mortality in women (HR = 0.85, CI: 0.79-0.92) and men (HR = 0.83, CI: 0.78-0.89), with no interaction by OPA. Non-occupational physical activity was associated with lower mortality in working women (HR = 0.89 per 5 kJ/day/kg, CI: 0.84-0.95) and men (HR = 0.87 per 5 kJ/day/kg, CI: 0.84-0.91), with no interaction by OPA group.

CONCLUSIONS

Jobs classified as higher levels of OPA may not be as active as reported, or the types of physical activity performed in those jobs are not health-enhancing. Irrespective of OPA category or employment status, non-occupational physical activity appears to provide health benefits.

The effect of leisure time physical activity and sedentary behaviour on the health of workers with different occupational physical activity demands: a systematic review

BACKGROUND

Although it is generally accepted that physical activity reduces the risk for chronic non-communicable disease and mortality, accumulating evidence suggests that occupational physical activity (OPA) may not confer the same health benefits as leisure time physical activity (LTPA). It is also unclear if workers in high OPA jobs benefit from LTPA the same way as those in sedentary jobs. Our objective was to determine whether LTPA and leisure time sedentary behaviour (LTSB) confer the same health effects across occupations with different levels of OPA.

METHODS

Searches were run in Medline, Embase, PsycINFO, ProQuest Public Health and Scopus from inception to June 9, 2020. Prospective or experimental studies which examined the effects of LTPA or LTSB on all-cause and cardiovascular mortality and cardiovascular disease, musculoskeletal pain, diabetes, metabolic syndrome, arrhythmias and depression among adult workers grouped by OPA (low OPA/sitters, standers, moderate OPA/intermittent movers, high OPA/heavy labourers) were eligible. Results were synthesized using narrative syntheses and harvest plots, and certainty of evidence assessed with GRADE.

RESULTS

The review includes 38 papers. Across all outcomes, except cardiovascular mortality, metabolic syndrome and atrial fibrillation, greater LTPA was consistently protective among low OPA, but conferred less protection among moderate and high OPA. For cardiovascular mortality and metabolic syndrome, higher levels of LTPA were generally associated with similar risk reductions among all OPA groups. Few studies examined effects in standers and none examined effects of LTSB across OPA groups.

CONCLUSIONS

Evidence suggests that LTPA is beneficial for all workers, but with larger risk reductions among those with low compared to high OPA jobs. This suggests that, in our attempts to improve the health of workers through LTPA, tailored interventions for different occupational groups may be required. More high-quality studies are needed to establish recommended levels of LTPA/LTSB for different OPA groups.

PROTOCOL REGISTRATION

PROSPERO # CRD42020191708 .

Occupational lifting and risk of hypertension, stratified by use of anti-hypertensives and age - a cross-sectional and prospective cohort study

Background

Heavy occupational lifting is prevalent in the general working population and is sparsely reported to associate with hypertension, especially among older and hypertensive workers. We investigated if heavy occupational lifting is associated with hypertension and blood pressure (BP) in both cross-sectional and prospective study designs in the Copenhagen General Population Study, stratified by age, and use of anti-hypertensives.

Methods

Participation was conducted following the declaration of Helsinki and approved by the ethical committee (H-KF-01-144/01). By multivariable logistic and linear regression models, we investigated the association between heavy occupational lifting and hypertension, in a cross-sectional design (n = 67,363), using anti-hypertensives or BP ≥140/≥90 mmHg as outcome, and in a prospective design (n = 7020) with an above-median change in systolic BP (SBP) from baseline to follow-up and/or a shift from no use to use of anti-hypertensives as outcome, with and without stratification by age and use of anti-hypertensives.

Results

The odds ratio for hypertension was estimated at 0.97 (99% CI: 0.93–1.00) in the cross-sectional analysis, and at 1.08 (99% CI: 0.98–1.19) in the prospective analysis. The difference in SBP among workers with versus without heavy occupational lifting was estimated at − 0.29 mmHg (99% CI -0.82 – 0.25) in the cross-sectional and at 1.02 mmHg (99% CI -0.41 – 2.45) in the prospective analysis. No significant interaction between heavy occupational lifting and age, nor use of anti-hypertensives were shown.

Conclusions

Only the prospective analysis indicated heavy occupational lifting to increase the risk of hypertension. Further research on the association between occupational lifting and hypertension are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10651-w.

Occupational physical activity and cardiovascular disease in the United States

BACKGROUND

Emerging evidence, predominately from European and Asian countries, describes opposing effects of occupational physical activity (OPA) and leisure-time physical activity (LTPA) on cardiovascular health. This analysis examined cardiovascular disease (CVD) prevalence associated with OPA and LTPA.

METHODS

This cross-sectional analysis of 2015 National Health Interview Survey data (n=16 974) employed logistic regression to estimate odds (OR) of self-reported CVD (coronary heart disease, heart attack, stroke or angina) with self-reported total occupational activity (TOA), occupational exertion (OE), occupational standing and walking (OSW) and LTPA. OPA was measured using two questions: 'How often does your job involve…' (1) 'repeated lifting, pushing, pulling or bending?' (OE) and (2) 'standing or walking around?' (OSW) with responses on a 5-item Likert scale (0=never, 4=always). TOA was categorised similarly after summing OE and OSW scores. LTPA was defined as 0, 1-149 or ≥150 min/week of moderate-to-vigorous activity. All models adjusted for common socioeconomic variables and additional analyses were stratified by sex, smoking status and LTPA.

RESULTS

Odds for CVD were higher when 'always' performing TOA (OR 1.99 95% CI 1.12 to 3.53), OE (OR 2.15, 95% CI 1.45 to 3.19) or OSW (OR 1.84, 95% CI 1.07 to 3.17) compared with 'never'. When restricting to never-smokers, odds for CVD were higher when 'always' performing TOA (OR 3.00, 95% CI 1.38 to 6.51) and OE (OR 3.00, 95% CI 1.80 to 5.02) versus 'never'.

CONCLUSION

Associations of high OPA with CVD were equally apparent across sexes, stronger in lower LTPA levels and stronger in never-smokers. While uncontrolled confounding is still possible, even after extensive adjustment, the seemingly paradoxical adverse associations with OPA and CVD should be investigated further.

Older Workers with Physically Demanding Jobs and their Cognitive Functioning

Although employment can provide older people with both financial and nonfinancial rewards, it is questionable whether those benefits extend to all older workers, particularly those with physically demanding jobs. This study aimed to examine whether the perceived level of physical demands placed on older workers 55 or older is significantly associated with their cognitive function. Using the Health and Retirement Study (HRS) 2010 wave, we analyzed two domains of cognition: verbal episodic memory and reasoning. After controlling for demographics and risk factors for age-related cognitive deterioration, the perceived level of physical demands placed on older workers was still significantly and negatively linked with both memory and reasoning domains of cognition. Older workers with more physically demanding jobs tended to have poorer cognitive function. Further longitudinal studies are needed to confirm this relationship.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12126-020-09404-8.

Effect of welding fumes on the cardiovascular system: a six-year longitudinal study

Objective This study investigated whether low-to-moderate exposure to welding fumes is associated with adverse effects on the cardiovascular system. Methods To test this, we performed a longitudinal analysis of 78 mild steel welders and 96 controls; these subjects were examined twice, six years apart (ie, timepoints 1 and 2). All subjects (male and non-smoking at recruitment) completed questionnaires describing their health, work history, and lifestyle. We measured their blood pressure, endothelial function (by EndoPAT), and risk markers for cardiovascular disease [low-density lioprotein (LDL), homocysteine, C-reactive protein]. Exposure to welding fumes was assessed from the responses to questionnaires and measurements of respirable dust in their breathing zones adjusted for use of respiratory protection equipment. Linear mixed-effect regression models were used for the longitudinal analysis. Results Median respirable dust concentrations, adjusted for respirable protection, of the welders were 0.7 (5-95 percentile range 0.2-4.2) and 0.5 (0.1-1.9) mg/m ³at timepoints 1 and 2, respectively. Over the six-year period, welders showed a statistically significant increase in systolic [5.11 mm Hg, 95% confidence interval (CI) 1.92-8.31] and diastolic (3.12 mm Hg, 95% CI 0.74-5.5) blood pressure compared with controls (multi-variable adjusted mixed effect models). Diastolic blood pressure increased non-significantly by 0.22 mm Hg (95% CI -0.02-0.45) with every additional year of welding work. No consistent significant associations were found between exposure and endothelial function, LDL, homocysteine, or C-reactive protein. Conclusion Exposure to welding fumes at low-to-moderate levels is associated with increased blood pressure, suggesting that reducing the occupational exposure limit (2.5 mg/m ³for inorganic respirable dust in Sweden) is needed to protect cardiovascular health of workers.

Occupational categories and cardiovascular diseases incidences: a cohort study in Iranian population

Introduction

In spite of traditional cardiovascular risk factor, the different occupations can play an important role in cardiovascular disease (CVDs) incidence. We aimed to assess the correlation between the occupational classes, based on the International Standard Classification of Occupation (ISCO), and CVDs in Iran as a developing country.

Methods

We followed the 2440 men, aged 35-65 years and without history of CVDs over fourteen years; 2001 to 2015 during the Isfahan Cohort Study. ISCO was used to classify occupations into 10 categories. Incidence rates of ischemic heart diseases and stroke were recorded. Socioeconomic demographic data including marital state, income and place of living and metabolic risk factors were also recorded.

Results

The mean age was 46.97 ± 8.31 years old. 272 cardiovascular events (CVEs) were recorded that unstable angina was the highest recorded with 49% prevalence and the fatal stroke had the lowest outbreak (1%). The unemployed/jobless group and elementary occupations (9th ISCO category) had higher and lower relative frequency in CVEs respectively. There was non-significant decrease in CVEs in all of categories except of 4^th (clerical support workers) and 10th (armed forces) groups in comparison to unemployed/jobless subjects (P > 0.05). After considering of the group 7 as a reference group (most absolute CVEs frequency), in fully adjustment analysis group 4 had significant risk for CVEs (P = 0.04).

Conclusions

This study indicates that working as clerical support workers (4^th ISCO category) is associated with higher significant risk for IHD and stroke incidence in comparison to craft and related trades workers (7^th group of ISCO).

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.

Occupational physical activity and all-cause and cardiovascular disease mortality: Results from two longitudinal studies in Switzerland

BACKGROUND

Research regarding the effects of occupational physical activity on health remains inconsistent. We analyzed the association of occupational physical activity with all-cause and cardiovascular disease (CVD) mortality.

METHODS

We analyzed two cohorts with baseline assessments from 1977 to 1993 ("National Research Program 1A" (NRP1A) and "MONItoring of trends and determinants in CArdiovascular disease" [MONICA]) and mortality follow-up until 2015 using adjusted Cox regression models.

RESULTS

We included 4396 NRP1A participants (137 793 person-years of follow-up, 1541 deaths) and 5780 MONICA participants (135 410 person-years, 1158 deaths). All-cause mortality was higher for men in the high compared with the low occupational physical activity category according to NRP1A (hazard ratio [HR] 1.25, 95% confidence intervals [CI] 1.05-1.50). CVD mortality was higher for men in the moderate compared with the low occupational physical activity category according to MONICA (HR, 1.41; 95% CI, 1.03-1.91). Results for women were not statistically significant.

CONCLUSIONS

We observed higher total and CVD mortality risks in men with higher occupational physical activity but inconsistent results for women and across cohorts.

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.

Physical workload and obesity have a synergistic effect on work ability among construction workers

PURPOSE

Obesity and high physical workload are both associated with poor work ability, but the interaction between obesity and high physical workload on work ability is not yet fully understood. Obesity and high physical workload may share a common mechanical pathway, possibly leading to a synergistic negative effect on work ability. The purpose of this study was to investigate the effect of obesity on work ability in workers with high versus low physical work load.

METHODS

A longitudinal study was conducted among 36,435 Dutch construction workers who participated in at least two periodic medical examinations during the years 2008-2015. Logistic regression analyses were used to investigate the effect of manual material handling and strenuous work postures in sports on the association between obesity and work ability. Work ability was measured using the self-reported Work Ability Index consisting of seven dimensions. Confounding effects were tested for age, educational level, smoking, vigorous physical activity, psychosocial work demands, and working hours. Additive interaction between obesity and physical workload on work ability was tested using the relative excess risk due to interaction (RERI).

RESULTS

Construction workers with overweight (OR = 1.09; 95% CI 1.02-1.16) or obesity (OR = 1.27; 95% CI 1.17-1.38) had an increased risk of poor/moderate work ability. Exposure to manual material handling (OR = 1.58; 95% CI 1.49-1.68) or strenuous work postures (OR = 1.80; 95% CI 1.70-1.90) also increased the risk of poor/moderate work ability. The effect of the combination of obesity with high physical workload was greater than the sum of the individual effects (strenuous work postures: RERI = 0.39; 95% CI 0.10-0.67; manual material handling: RERI = 0.26; 95% CI 0.02-0.51).

CONCLUSIONS

Obesity and high physical workload were associated with poor work ability and had a synergistic, negative effect on work ability. Interventions that prevent obesity and high physical workload might have a beneficial effect on work ability.

Can socioeconomic health differences be explained by physical activity at work and during leisure time? Rationale and protocol of the active worker individual participant meta-analysis

INTRODUCTION

Socioeconomic health differences have often been described, but remain insufficiently understood. Recent evidence suggests that workers who are high (compared with low) physically active at work are less healthy. Moreover, workers who are highly physically active at work are predominantly physically inactive during leisure time. These observations suggest that workers with a lower socioeconomic status may be exposed to negative health consequences of occupational physical activity and may only benefit to a limited extent from health benefits of leisure-time physical activity. Physical activity may therefore be an important driver of socioeconomic health differences. We describe the rationale and protocol of the active worker study, an individual participant data meta-analysis aimed at exploring socioeconomic health differences by differential doses of physical activity at work and leisure time.

METHODS AND ANALYSIS

Using database and scoping searches (we searched in PubMed, Embase, CINAHL, PsycINFO and Evidence-Based Medicine Reviews from database inception to 14 September 2017), we have identified 49 published and unpublished prospective studies in which the association of occupational and leisure-time physical activity with cardiovascular or all-cause mortality was assessed. Principal investigators of these studies will be invited to participate in the active worker consortium, after which data will be retrieved. After data merging and harmonising, we will perform multilevel survival analysis assessing the combined association of occupational and leisure-time physical activity with mortality. We will also test the mediating effect of physical activity on the association of socioeconomic status and mortality (ie, socioeconomic health differences).

DISCUSSION

The Medical Ethical Committee of the VU University Medical Center has declared, according to Dutch legislation, that the 'Dutch Medical Research Involving Human Subjects Act' does not apply to the current study. As such, no ethics approval is required. We intent to publish outcomes of the active worker Study in scientific peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42018085228.

Occupational Physical Activity and Cardiovascular Risk Factors Profile in the Adult Population of the Southern Cone of Latin America: Results From the CESCAS I Study

OBJECTIVE

We explore the association between occupational physical activity (OPA) and cardiovascular risk factors in four cities of the Southern Cone.

METHODS

Robust multivariable linear regression models were used to examine the associations.

RESULTS

The working population was constituted by 1868 men and 1672 women. Men performing high levels of OPA showed higher levels of high-density lipoprotein (HDL; mean adj. diff. = 2.24 mg/dL; P = 0.004), lower levels of triglycerides (-24.59 mg/dL; P = 0.006), and total cholesterol (TC)/HDL ratio values (-0.21; P = 0.015) than reference. Women in the highest category of OPA had higher levels of HDL (2.85 mg/dL; P = 0.006), lower TC/HDL (0.27; P = 0.001), and low-density lipoprotein/HDL ratios (-0.18; P = 0.003) than sedentary activities.

CONCLUSION

Individuals who performed high levels of OPA did not exhibit a worse cardiovascular risk profile and an improvement on selected biomarkers was observed when compared with those performing sedentary activities.

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.

The Effect of Occupational Lifting on Hypertension Risk: Protocol for a Project Using Data From the Copenhagen City Heart Study

BACKGROUND

Hypertension is a major risk factor for cardiovascular disease and is responsible for 14% of all annual deaths globally. The prevalence of hypertension varies across occupational groups, possibly affected by differences in the working environment. One work-related factor that might impose a risk for hypertension is lifting due to the acute large increases in blood pressure (BP) during lifting.

OBJECTIVE

The aim of this study is to explore associations between heavy occupational lifting and hypertension in the Copenhagen City Heart Study.

METHODS

This study will use data from the third, fourth, and fifth examination of the Copenhagen City Heart Study. The dataset contains person-based information on health as well as a large variety of biological, environmental, and lifestyle-related factors. Using a cross-sectional design, we will investigate the association between heavy occupational lifting and hypertension, defined as using antihypertensive drugs or having a measured systolic BP (SBP) ≥140 mm Hg or diastolic BP (DBP) ≥90 mm Hg. Furthermore, in a prospective design, we will investigate the association between heavy occupational lifting and risk of becoming an SBP case, defined as the shift from not using antihypertensive drugs in examination n to use of antihypertensive drugs in examination n+1 or an above median delta value of SBP (SBP in examination n+1−SBP in examination n).

RESULTS

In the third examination in 1991-1994, 10,135 out of 16,560 participants attended (61.20%), in the fourth examination in 2001-2003, 6237 out of 12,599 participants attended (49.50%), and in the fifth examination in 2011-2015, 4550 out of 9765 participants attended (46.59%). On the basis of the inclusion criteria of answering to the level of occupational physical activity, 5031 observations were excluded from examination 3, 2600 from examination 4, and 1621 from examination 5. Hence, the final populations for the cross-sectional and prospective analysis are assumed to include less than 7166 participants in the cross-sectional analysis and less than 1850 participants in the prospective analysis due to the additional inclusion criteria of measured BP and use of antihypertensive drugs.

CONCLUSIONS

One-third of the workforce in Europe reports to carry or move heavy loads regularly during working hours (6th survey in Eurofound). Thus, if this study shows occupational lifting to increase the risk for hypertension, the prevention for hypertension can be improved.

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.

Childhood Socioeconomic Disadvantage, Occupational, Leisure-Time, and Household Physical Activity, and Diabetes in Adulthood

BACKGROUND

Regular physical activity is a key way to prevent disease. However, we have a limited understanding of the socioeconomic precursors and glucoregulatory sequelae of engaging in physical activity in different domains.

METHODS

We examined the associations among life course socioeconomic disadvantage; meeting the physical activity guidelines with leisure-time physical activity, occupational physical activity, or household physical activity; and prediabetes and diabetes in the Midlife in the United States national study (N = 986).

RESULTS

Childhood disadvantage was associated with lower odds of meeting the guidelines with leisure-time physical activity (odds ratio = 0.75; 95% confidence interval, 0.65-0.86). Adulthood disadvantage was associated with higher odds of meeting the guidelines with occupational physical activity (odds ratio = 1.94; 95% confidence interval, 1.49-2.53). Importantly, while meeting the guidelines with leisure-time physical activity was associated with lower odds of prediabetes and diabetes, we found no evidence for associations among occupational physical activity, household physical activity, and glucoregulation.

CONCLUSION

Current US physical activity guidelines do not differentiate between physical activity for leisure or work, assuming that physical activity in any domain confers comparable health benefits. We documented important differences in the associations among lifetime socioeconomic disadvantage, physical activity domain, and diabetes, suggesting that physical activity domain potentially belongs in the guidelines, similar to other characteristics of activity (eg, type, intensity).

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.

Occupational physical activity assessment for chronic disease prevention and management: A review of methods for both occupational health practitioners and researchers

Occupational physical activity (OPA) is an occupational exposure that impacts worker health. OPA is amenable to measurement and modification through the hierarchy of controls. Occupational exposure scientists have roles in addressing inadequate physical activity, as well as excessive or harmful physical activity. Occupational health researchers can contribute to the development of novel OPA exposure assessment techniques and to epidemiologic studies examining the health impacts of physical activity at work. Occupational health practitioners stand to benefit from understanding the strengths and limitations of physical activity measurement approaches, such as accelerometers in smartphones, which are already ubiquitous in many workplaces and in some worksite health programs. This comprehensive review of the literature provides an overview of physical activity monitoring for occupational exposure scientists. This article summarizes data on the public health implications of physical activity at work, highlighting complex relationships with common chronic diseases. This article includes descriptions of several techniques that have been used to measure physical activity at work and elsewhere, focusing in detail on pedometers, accelerometers, and Global Positioning System technology. Additional subjective and objective measurement strategies are described as well.

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.

Association of physical workload and leisure time physical activity with incident mobility limitations: a follow-up study

OBJECTIVES

To examine individual as well as joint associations of physical workload and leisure time physical activity with incident mobility limitations in initially well-functioning middle-aged workers.

METHODS

This study is based on 6-year follow-up data of the Danish Longitudinal Study on Work, Unemployment and Health. Physical workload was reported at baseline and categorised as light, moderate or heavy. Baseline leisure time physical activity level was categorised as sedentary or active following the current recommendations on physical activity. Incidence of mobility limitations in climbing stairs and running among initially well-functioning workers (n=3202 and n=2821, respectively) was assessed during follow-up.

RESULTS

Higher workload increased whereas active leisure time decreased the risk of developing mobility limitations. The incidence of limitations increased progressively with higher workload regardless of level of leisure time physical activity, although the risks tended to be higher among those with sedentary leisure time compared with their active counterparts. All in all, the risk for onset of mobility limitations was highest among those with heavy workload combined with sedentary leisure time and lowest among those with light workload combined with active leisure time.

CONCLUSIONS

Although leisure time physical activity prevents development of mobility decline, high workload seems to accelerate the progression of mobility limitations among both those with active and sedentary leisure time. Therefore, efforts should be made to recommend people to engage in physical activity regardless of their physical workload.

Physical activity and risk of cardiovascular disease: what does the new epidemiological evidence show?

PURPOSE OF REVIEW

Abundant evidence has documented inverse associations of physical activity and the risk of cardiovascular disease (CVD). However, the effects of different types of physical activity (e.g., leisure time and occupational physical activity) are still poorly understood.

RECENT FINDINGS

Drawing on recommended and established guidelines for study selection, we identified and included 23 prospective epidemiological studies published during the last 2 years. These studies included a total of more than 790 000 adults at baseline with some 22 000 incident cases occurring during follow-up. Our findings suggest that moderate and high levels of leisure time physical activity are associated with a moderately reduced risk of CVD. In contrast, moderate and high levels of occupational physical activity showed weak positive associations, that is, a slightly increased risk of CVD.

SUMMARY

This updated meta-analysis supports the notion of primary prevention of CVD through engagement in leisure time physical activity. The role of occupational physical activity in CVD prevention is questionable.

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.