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

Physical Activity and Bladder Cancer Risk: Findings of the Japan Collaborative Cohort Study

PURPOSE

The association of physical activity with the risk of bladder cancer remains inconsistent among Asian populations. We aimed to examine the association in a large Japanese cohort.

MATERIALS AND METHODS

In a population-based prospective cohort study, a total of 50,374 Japanese adults aged 40-79 years without a history of cancer or cardiovascular disease who had information on physical activity from self-administrated questionnaires were used for analysis. We performed Cox proportional hazard models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident bladder cancer after adjusting for several potential confounders.

RESULTS

During the median 17.5 years of follow-up, 153 incident bladder cancers (116 men and 37 women) were identified. After the multivariable adjustment, HRs (95% CI) of bladder cancer concerning those with recreational sports participation of 1-2 hr/wk, 3-4 hr/wk, and 5 hr/wk and more were 0.67 (0.38-1.20), 0.79 (0.36-1.74), and 0.28 (0.09-0.89), respectively (p for trend=0.017). Compared with mostly sitting at the workplace, occupational physical activity of standing and walking were associated with a lower risk of bladder cancer (HR, 0.53 [95% CI, 0.32 to 0.85]). Hours of daily walking were not associated with the risk. The lower risk of bladder cancer was more evident for recreational sports (HR, 0.33 [95% CI, 0.10 to 1.00]), and for occupational standing and walking activity at work (HR, 0.57 [95% CI, 0.33 to 0.98]) among men.

CONCLUSION

Recreational sports participation and occupational physical activity were inversely associated with the risk of bladder cancer among Japanese, especially in men.

Re: Cillekens B, Huysmans MA, Holtermann A, van Mechelen W, Straker L, Krause N, van der Beek AJ, Coenen P. Physical activity at work may not be health enhancing. A systematic review with meta-analysis on the association between occupational physical activity and cardiovascular disease mortality covering 23 studies with 655 892 participants. Scand J Work Environ Health. 2022;48(2):86-98. doi:10.5271/sjweh.3993

Objectives

Emerging evidence suggests contrasting health effects for leisure-time and occupational physical activity. In this systematic review, we synthesized and described the epidemiological evidence regarding the association between occupational physical activity and cardiovascular disease (CVD) mortality.

Methods

A literature search was performed in PubMed, Embase, CINAHL, PsycINFO and Evidence-Based Medicine Reviews, from database inception to 17 April 2020. Articles were included if they described original observational prospective research, assessing the association between occupational physical activity and CVD mortality among adult workers. Reviews were included if they controlled for age and gender and at least one other relevant variable. We performed meta-analyses on the associations between occupational physical activity and CVD mortality.

Results

We screened 3345 unique articles, and 31 articles (from 23 studies) were described in this review. In the meta-analysis, occupational physical activity showed no significant association with overall CVD mortality for both males [hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.84–1.12] and females (HR 0.97, 95% CI 0.82–1.15). Additional analysis showed that higher levels of occupational physical activity were non-significantly associated with a 9% increase in studies reporting on the outcome ischemic heart disease mortality (HR 1.09, 95% CI 0.82–1.43).

Conclusions

While the beneficial association between leisure-time physical activity and CVD mortality has been widely documented, occupational physical activity was not found to have a beneficial association with CVD mortality. This observation may have implications for our appreciation of the association between physical activity and health for workers in physically demanding jobs, as occupational physical activity may not be health enhancing.

Does stressful workplace characteristics moderate or confound the association between occupational physical activity and elevated depressive symptoms? A large study including 36,442 adults

BACKGROUND

We tested whether stressful workplace characteristics confound or moderate the association between occupational physical activity and depressive symptoms.

METHOD

We used data of 36,442 employed adults (16,992 women), with a mean age of 39.3 ± 12.6y, from the 2013 Brazilian National Health Survey. Depressive symptoms were assessed through the Patient Health Questionnaire-9 (cut-point: ≥10). Occupational physical activity was self-reported and classified using the cut-point of 150 min/week and the highest quintile. Ten stressful workplace characteristics (e.g. exposure to stress, noise, violence) were also self-reported dichotomously. Logistic regression models were used considering the adjustment for potential confounders.

RESULTS

Most of the stressful workplace characteristics were associated with elevated depressive symptoms (8/10 characteristics) and higher occupational physical activity (9/10 characteristics). Although there were no interactions in combined associations, we found that the association between occupational physical activity and depressive symptoms consistently reduced after adjusting for the cluster of positive screening for at least two stressful workplace characteristics in men [highest quintile: OR_unadjusted: 1.63 (95%CI 1.22-2.17) vs OR_adjusted: 1.36 (1.08-1.91); ≥150 min/week: OR_unadjusted: 1.43 (1.09-1.88) vs OR_adjusted: 1.25 (0.95-1.64)], and women [highest quintile: OR_unadjusted: 2.15 1.73-2.66) vs OR_adjusted: 1.83 (1.47-2.29); ≥150 min/week: OR_unadjusted: 2.11 (1.68-2.65) vs OR_adjusted: 1.80 (1.42-2.27)].

LIMITATIONS

The cross-sectional design limits the causal inference.

CONCLUSIONS

Stressful workplace characteristics did not moderate, but acted as confounders in the association between occupational physical activity and elevated depressive symptoms and should be considered in future studies.

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.

Heart rate during work and heart rate variability during the following night: a day-by-day investigation on the physical activity paradox among blue-collar workers

Objectives:

Contrary to leisure-time physical activity, occupational physical activity (OPA) may have harmful health effects, called the physical activity paradox. A proposed mechanism is that OPA can elevate the heart rate (HR) for several hours per day. We aimed to investigate the association between the mean intensity of OPA and HR variability (HRV) indices the following night.

Methods:

Three cohorts (NOMAD, DPhacto, and Physical Workload and Fitness) involving blue-collar workers from different sectors were merged in this study. HR monitors (Actiheart) recorded 24-hour inter-beat intervals (IBI) for up to four consecutive days. The relative intensity of the mean HR during work was estimated by HR reserve (%HRR), and time-domain indices of HRV were analyzed during the following night. Data were analyzed using a multilevel growth model to test the association between mean %HRR during work and HRV indices at night in a day-by-day analysis adjusted for age, BMI, alcohol consumption, smoking, and occupation.

Results:

The dataset included a sample of 878 Danish blue-collar workers, with a mean %HRR during work of 31%, and 42% worked at an intensity ≥30%HRR. The multilevel model showed negative within- and between-subject associations between %HRR during work and HRV indices at night.

Conclusions:

Our results indicate a higher %HRR during work to associate with lower HRV indices the following night and a higher HR, reflecting an imbalanced autonomic cardiac modulation. This finding supports a high mean HR during work to be a potential underlying mechanism for the harmful health effect of OPA.

Exercise Habits Are Associated with Improved Long-Term Mortality Risks in the Nationwide General Japanese Population: A 20-Year Follow-Up of the NIPPON DATA90 Study

Exercise habits are known as a protective factor for a variety of diseases and thus recommended worldwide; however, few studies have examined long-term effects of exercise habits on mortality. We continuously monitored death status in a nationwide population sample of 7,709 eligible persons from the National Integrated Project for Prospective Observation of Noncommunicable Disease and its Trends in the Aged in 1990 (NIPPON DATA90), for which baseline data were obtained in 1990. To investigate the long-term impact of baseline exercise habits, we calculated the relative risk of non-exercisers (participants without regular voluntary exercise habits) in reference to exercisers (those with these habits) for all-cause or cause-specific mortality using a Cox proportional hazard model, in which the following confounding factors were appropriately adjusted: sex, age, body mass index, total energy intake, smoking, drinking, and history of cardiovascular disease. During a median 20 years of follow-up, 1,747 participants died, 99 of heart failure. The risk for all-cause mortality was 12% higher in non-exercisers than in exercisers (95% confidence interval, 1%-24%), which was also observed for mortality from heart failure, as 68% higher in non-exercisers than in exercises (95% confidence interval, 3%-173%). These associations were similarly observed when the participants were divided to subgroups by sex, age, and the light, moderate, or vigorous intensity of physical activity, without any significant heterogeneities (P > 0.1). The present study has revealed significant impact of exercise habits on long-term mortality risks, supporting worldwide recommendations for improvement of exercise habits.

Socioeconomic and demographic predictors of high blood pressure, diabetes, asthma and heart disease among adults engaged in various occupations: evidence from India

In India, non-communicable diseases (NCDs) accounted for nearly 62% of all deaths in 2016. Four NCDs - high blood pressure, diabetes, asthma and heart disease - together accounted for over 34% of these deaths. Using data from two rounds of the India Human Development Surveys (IHDSs), levels and changes in the prevalence rates of the four NCDs (based on diagnosed cases) among adults aged 15-69 years in India between 2004-05 and 2011-12 were examined by socioeconomic and demographic factors and for five broad occupation categories. The socioeconomic and demographic risk factors for each of these NCDs were determined using multiple linear logistic regression analysis of pooled data from two rounds of the IHDS. The results showed that while urban residence, age, female sex and education were associated with higher odds of high blood pressure, diabetes and heart disease, household economic status was associated with higher odds for all four NCDs. Furthermore, increased higher odds of high blood pressure, diabetes and heart disease were found for the legislator/senior official/professional occupation group compared with non-workers. Skilled agricultural/elementary workers had lower odds of high blood pressure, diabetes, asthma and heart disease. Craft/machine-related trade workers had higher odds of high blood pressure and diabetes, and reduced odds of asthma and heart disease. Compared with non-workers, the odds ratios for asthma were lower for all other occupational categories. During the two study decades, the Government of India implemented several programmes designed to improve the health and well-being of its people. However, more focused attention on the adult population is needed, and special attention should be paid to the issue of the occupational health of the working population through the strict implementation of work place safety protocols and the removal of potential health hazards.

Objectively Measured Sitting and Standing in Workers: Cross-Sectional Relationship with Autonomic Cardiac Modulation

Excessive sitting and standing are proposed risk factors for cardiovascular diseases (CVDs), possibly due to autonomic imbalance. This study examines the association of objectively measured sitting and standing with nocturnal autonomic cardiac modulation. The cross-sectional study examined 490 blue-collar workers in three Danish occupational sectors. Sitting and standing during work and leisure were assessed during 1⁻5 days using accelerometers. Heart rate (HR) and heart rate variability (HRV) were obtained during nocturnal sleep as markers of resting autonomic modulation. The associations of sitting and standing still (h/day) with HR and HRV were assessed with linear regression models, adjusted for age, gender, body mass index, smoking, and physical activity. More sitting time during leisure was associated with elevated HR (p = 0.02), and showed a trend towards reduced HRV. More standing time at work was associated with lower HR (p = 0.02), and with increased parasympathetic indices of HRV (root mean squared successive differences of R-R intervals p = 0.05; high-frequency power p = 0.07). These findings, while cross-sectional and restricted to blue-collar workers, suggest that sitting at leisure is detrimental to autonomic cardiac modulation, but standing at work is beneficial. However, the small effect size is likely insufficient to mitigate the previously shown detrimental effects of prolonged standing on CVD.

Lower limb blood flow and mean arterial pressure during standing and seated work: Implications for workplace posture recommendations

Sit-stand workstations are a popular workplace intervention. Organizations often require a medical professional's guidance for implementation. Therefore, it is important to understand potential negative outcomes associated with standing work, such as lower limb discomfort and peripheral vascular issues. The objective of this study was to compare changes in lower limb discomfort, blood pressure and blood flow accumulation during a light-load repetitive upper limb work task accomplished from seated and standing postures. At the Jewish Rehabilitation Hospital (Laval, Quebec, Canada), 16 participants were outfitted with Laser Doppler Flow (LDF) electrodes to measure blood flow in the lower limb, and a sphygmomanometer to measure lower limb mean arterial blood pressure (MAP). Participants completed simulated work over 34 min in standing and seated conditions. Repeated measures ANOVAs (Posture x Time) were used to assess the differences. There were significant effects for both Posture (p = 0.003) and Time (p = 0.007) for LDF-measured of blood flow accumulation in the soleus and the foot, with a mean increase of 77% blood flow over time in the standing posture, when compared to seated work. There was a significant 'Posture × Time' (p = 0.0034) interaction effect and a significant Posture (p = 0.0001) effect for MAP, with higher values in the standing posture by a mean of 37.2 mmHg. Posture had a significant effect (p < 0.001) on lower limb discomfort, with standing posture reporting higher levels. These results suggest that recommendations for using static standing work postures should be tempered, and physicians' guidance on workstation changes should consider the impacts on the lower limb.

The relationship between meeting of recommendations on physical activity for health and perceived work ability among white-collar workers

OBJECTIVE

The aim of this study was to evaluate the association between meeting recommendations on physical activity for health in leisure-time and the ability to work among Polish white-collar workers.

METHODS

The study used a cross-sectional design with a convenience sample of 360 white-collar workers. Participants recorded 7-day physical activity logs, including form, duration and intensity of leisure-time physical activities. The results were compared to health recommendations. A standardized Work Ability Index (WAI) questionnaire was used in assessing the ability to work.

RESULTS

Participants who met health recommendations achieved higher scores of the WAI (mean score = 41.93) in comparison to those who were not sufficiently physically active (mean score = 39.35) (p < .001). The results of binary logistic regression show that meeting health-related physical activity recommendations almost double the odds of reaching at least good work ability (OR = 1.94, 95% CI = 1.12-3.36).

CONCLUSIONS

Meeting leisure-time physical activity recommendations (especially the criterion of vigorous physical activity) is significantly related to higher self-assessed ability to work among white-collar workers.

Study on association of working hours and occupational physical activity with the occurrence of coronary heart disease in a Chinese population

Objective

To explore the association of working hours and occupational physical activity (OPA) with the occurrence of coronary heart disease (CHD) in a Chinese population.

Methods

A total of 595 participants (354 and 241 patients with and without CHD, respectively) aged between 24 and 65 were enrolled in our study, which was conducted at the First Affiliated Hospital of Nanjing Medical University between December 2015 and October 2016. Participant characteristics were collected from face-to-face questionnaires, and logistic regression analysis was conducted to examine the association of working hours and OPA with the occurrence of CHD.

Results

Compared with non-employed people, long working hours (especially ≥55 hours/week) contributed to the occurrence of CHD (adjusted odds ratio[OR] = 2.213, 95% confidence interval [CI]: 1.125, 4.355, P = 0.021) after multivariate adjustment in the Chinese population. With the extension of worktime, the CHD risk increased (P for the dose-response trend = 0.022). Meanwhile, even after adjusting for engagement in physical activity during leisure time, sedentary behavior at work had an adverse effect on CHD risk (adjusted OR = 2.794, 95%CI: 1.526, 5.115, P = 0.001), and a linear relationship was also found between OPA and CHD (P for the trend = 0.005).

Conclusions

Long working hours and sedentary behavior at work are associated with a high risk of CHD. In addition, prolonged working hours in sedentary occupations increases the risk of CHD, independent of engagement in leisure time physical activity.

Impact of physical activity category on incidence of cardiovascular disease: Results from the 10-year follow-up of the ATTICA Study (2002-2012)

The aim of the study was to examine the effects of physical activity (PA) level on 10-year cardiovascular disease (CVD) incidence, taking into consideration several clinical and lifestyle risk factors along with the potential moderating role of gender. An analysis was undertaken on data from the ATTICA prospective cohort study (10-year follow-up, 2002-2012), which followed a Greek adult population (aged 18-89years). A total n=317 of fatal and nonfatal CVD events occurred among the 2020 participants. After adjusting for the lifestyle and clinical risk factors as potential confounders, odds ratio (ORs) of CVD risk of individuals who reported being sufficiently active and highly active were decreased by 58% (95% CI: 0.30, 0.58) and 70% (95% CI: 0.15, 0.56), when compared to those who were inactive/insufficiently active, respectively. Men had nearly two-fold increase in risk of CVD (95% CI: 1.62, 2.18) versus women. Stratified analysis by gender, revealed that sufficiently active men, had 52% (95% CI: 0.24, 0.97) reduced risk of CVD incidence when compared to inactive males, while, for women, the role of PA lost significance following adjusting for lifestyle factors. The current data suggests a beneficial effect of even moderate physical activity levels on 10-year incidence of CVD, reinforcing the importance of physically activity, especially for men.

Where to Sit? Type of Sitting Matters for the Framingham Cardiovascular Risk Score

Background

Current evidence on associations of type-specific sedentary behavior with cardiovascular disease (CVD) is limited to mainly screen-time sedentary behavior (SB). We aimed to study the associations of type-specific and total time spent sitting with the Framingham 10-year cardiovascular disease risk score (Framingham score) in Finnish adults.

Methods

Data comprise the National FINRISK 2007 and 2012 health examination surveys with 10,185 participants aged 25–74 years, apparently free of CVD. Participants reported average daily time spent sitting in different locations: work-related sitting, at home in front of television (TV), at home in front of computer, in a vehicle, and elsewhere. Total SB time was calculated from these context-specific self-reports. Accelerometer-based sedentary time was assessed in 988 FINRISK 2012 participants. Framingham score was calculated using information on blood pressure and its medication, cholesterol levels, age, diabetes status, and smoking. Analyses were adjusted for age, study year, education, employment status, leisure time physical activity, and body mass index.

Results

Out of several type-specific sitting behaviors, only TV sitting showed systematic associations with the Framingham score in both genders. The lowest Framingham risk was found for TV sitting from 6 minutes to less than 1 hour daily. Of other types of sitting, computer sitting was inversely associated with the Framingham risk in men only. Total self-reported sitting time did not show significant associations with the Framingham score, but instead higher objectively assessed sedentary time showed higher Framingham risk in men.

Conclusions

TV sitting showed most systematic associations with CVD risk score. This suggests that of all types of SB, reducing TV sitting should be targeted for reducing CVD risk.