Long working hours and risk for hypertension in Japanese male white collar workers

Enhanced body shape change coupled with PA is the key to hypertension management for urban residents

The present study aimed to assess the relationship between body shape, physical activity (PA), and systolic blood pressure (SBP) and diastolic blood pressure (DBP). A novel visualization method was used to examine the effects of body shape combined with physical activity on hypertension. Data from 54,303 participants were obtained from the China Health and Nutrition Survey (CHNS) and analyzed using logistic regression models and standardized regression coefficients of linear models. These models were used to explore factors and effects of body shape indices and other parameters on SBP and DBP. The logistic regression model revealed that compared to transport-related PA, the aggregated variables (weight and waist) were associated with a 2.44-fold and 1.65-fold increase in the risk of hypertension, respectively (p < .05). The average aggregated standardized coefficient of the linear model, based on 1000 bootstrap resamples, indicated that the Base Shape group had the strongest explanatory power for hypertension, followed by the Habits group. However, the explanatory power of the PA group was around 10 and 22 times lower than that of the Base Shape group for DBP and SBP, respectively (p < .05). These results demonstrate that increasing physical activity, with emphasizing a healthy body shape, and adopting positive lifestyle habits can effectively contribute to the prevention and control of hypertension.

Systematic review and meta-analysis of the association between long working hours and hypertension risk

BACKGROUND

Hypertension, a major public health problem worldwide, has been linked to lifestyle factors and work conditions, with conflicting evidence on the association between long work hours and risk of hypertension.

METHODS

We conducted a systematic review and meta-analysis of observational studies to investigate the relationship between working hours and hypertension or blood pressure, assessed the risk of bias and performed subgroup analyses. The protocol was registered with the International Prospective Register of Systematic Reviews.

RESULTS

The pooled OR for the association between long working hours and risk of hypertension was 1.09 (95% CI: 0.88 to 1.35) in the 15 studies that used hypertension as the outcome. In the three studies that used blood pressure as the outcome, diastolic blood pressure was higher among those with long working hours compared with those with non-long working hours (1.24 mm Hg, 95% CI: 0.19 to 2.29). In subgroup analysis, the pooled OR for the association between long working hours and risk of hypertension was 1.28 (95% CI: 1.14 to 1.44) and 1.00 (95% CI: 0.64 to 1.56) in women and men, respectively.

CONCLUSIONS

Although this study could not clearly confirm the relationship between long working hours and hypertension, the subgroup analysis suggests that long working hours may be associated with hypertension, particularly among women. More reliable research is needed to establish causality.

PROSPERO REGISTRATION NUMBER

CRD42023406961.

The impact of long working hours on daily sodium intake

Background

Long working hours are associated with an increased risk of cardiovascular disease, yet the underlying mechanism(s) remain unclear. The study examines how occupational factors like working hours, shift work, and employment status correlate with dietary choices and sodium intake, impacting hypertension risk.

Methods

This study used data from the Korea National Health and Nutrition Examination Survey conducted between 2013 and 2020. The dataset included 8,471 respondents, all of whom were wage workers aged 20 or older and reported working at least 36 hours per week. Individuals who have been previously diagnosed with or are currently diagnosed with hypertension, diabetes, or dyslipidemia were excluded. The average daily sodium intake was assessed via a 24-hour dietary recall method. Average weekly working hours were categorized into 3 groups: 36-40 hours, 41-52 hours, and over 52 hours. Multiple logistic regression models were used.

Results

Study findings revealed that 83.7% of participants exceeded the recommended daily sodium intake of 2 g set by the World Health Organization. After adjusting for confounding factors, a positive correlation was observed between average working hours and daily sodium intake. Among males, statistical significance was found in the group with average weekly working hours of 41-52 hours (prevalence ratio [PR]: 1.17; 95% confidence interval [CI]: 1.05-1.30) and the group exceeding 52 hours (PR: 1.22; 95% CI: 1.09-1.38) when comparing the fourth quartile of daily sodium intake to the combined quartiles of Q1, Q2, and Q3. Among females, no significance was noted.

Conclusions

Long working hours were associated with increased sodium intake, primarily among male workers. This connection is likely attributed to having less time for home-cooked meals, resulting in higher fast food consumption and dining out. A workplace intervention promoting healthy eating and reducing stress is essential to lower sodium consumption and mitigate hypertension risk.

Cardiovascular Risk Factors in Hospital Workers during the COVID-19 Pandemic: A Hospital-Based Repeated Measures Study

Although many studies have investigated burnout, stress, and mental health issues among health care workers (HCWs) during the COVID-19 pandemic, few have linked these relationships to chronic physiological illnesses such as cardiovascular diseases. This study assessed changes in cardiovascular risk factors in HCWs and other hospital workers during the COVID-19 pandemic and identified vulnerable groups at a higher risk of increased adverse cardiovascular conditions. Five hundred and fourteen hospital employees ≥ 20 years of age underwent physical examinations and laboratory testing once before and once after the first wave of the pandemic in Taiwan during 2020 and 2021. Their sociodemographic characteristics and cardiovascular risk factors, including blood pressure, blood biochemical parameters, and body mass index, were collected. The differences between pre- and post-pandemic measurements of their biophysical and blood biochemical parameters were analyzed using pairwise tests. The post-pandemic increases in their parameter levels and cardiovascular risk as a function of underlying factors were estimated from multivariate regressions. HCWs showed significant increases in levels and abnormal rates of BMI, blood pressure, plasma glucose, and total cholesterol after the pandemic. Post-pandemic increases in BMI, waist circumference, and blood pressure were higher in females than in males. Workers with higher levels of education or longer job tenure had greater increases in BMI, triglyceride, and total cholesterol levels than other workers. Females had a higher incidence of abnormal BMI and hypertension than males (adjusted odds ratios [AORs] of 8.3 and 2.9, respectively). Older workers' incidence of hypertension was higher than younger workers' (AOR = 3.5). Preventive strategies should be implemented for HCWs susceptible to cardiovascular diseases during emerging infectious disease outbreaks.

Body weight and lifestyle changes under the COVID-19 pandemic in Japan: a cross-sectional study from NIPPON DATA2010

OBJECTIVES

The COVID-19 pandemic has had an impact on people's lifestyles such as causing body weight changes. This study examined associations among lifestyle changes and body weight during the COVID-19 pandemic among the Japanese population.

DESIGN

A cross-sectional study.

SETTING

A nationwide survey of the general Japanese population.

PARTICIPANTS

Total participants were 2244 men and women, of which 911 young/middle-aged (30-69 years old) and 899 older adults (70 years and older) were analysed separately.

OUTCOME

Changes in lifestyle (physical activity, dietary habits and alcohol intake) and body weight during the first wave of COVID-19 in spring 2020.

RESULTS

Under the COVID-19 pandemic, 24.1% and 10.1% of Japanese respondents reported weight gain and reduction, respectively. Multivariable-adjusted stepwise logistic regression analyses revealed that the young/middle-aged respondents in the group increased body weight, weight gain was significantly associated with decrease in physical activity (OR 4.01, 95% CI 2.83 to 5.69) and both increase (OR 5.82, 95% CI 3.85 to 8.80) and decrease (OR 2.73, 95% CI 1.52 to 4.93) in eating between meals. In the group that decreased body weight, body weight reduction was significantly associated with increase in physical activity (OR 3.66, 95% CI 1.94 to 6.90), decrease in eating between meals (OR 5.97, 95% CI 3.11 to 11.48) and both increase and decrease in alcohol intake in the young/middle age. For the older adults, body weight gain was higher in women than in men, and significantly associated with higher quartile of regional COVID-19 infection, decrease in physical activity (OR 2.98, 95% CI 1.98 to 4.49), increase in home-cooked meals and increase in eating between meals (OR 4.22, 95% CI 2.55 to 6.99). On the other hand, body weight reduction was significantly associated with decreases in physical activity (OR 2.63, 95% CI 1.62 to 4.27), home-cooked meals and eating between meals (OR 1.95, 95% CI 1.05 to 3.61) in the older adults.

CONCLUSION

Changes in physical activity and eating between meals were associated with body weight change under the COVID-19 pandemic among Japanese.

Occupational risk factors for hypertension

The identification and characterization of the modifiable risk factors of hypertension is of great value for public health and clinical medicine to achieve primary prevention. A large amount of literature on the effects of occupational factors on blood pressure and hypertension has been published. In this review, I summarize current evidence regarding the role of occupational factors in hypertension. The results of this review suggest that there is sufficient evidence to support the association between increased risk of hypertension and job stress, shift work, occupational lead exposure, and noise exposure. The association of hypertension with physical inactivity, sedentary behavior, and occupational exposure to mercury, arsenic, cadmium, or carbon disulfide remains inconclusive, although several studies have reported this finding. This review will serve as a step toward future research and provide baseline information for developing strategic interventions to prevent hypertension in the working population.

Prevalence of hypertension and its risk factors among cotton textile workers in low- and middle-income countries: a systematic review

OBJECTIVE

The objective of this study was to evaluate the prevalence of hypertension and its risk factors among adult cotton textile workers in low- and middle-income countries (LMICs).

STUDY DESIGN

Systematic review.

METHODS

A review of English articles was performed between January 1, 2000, and December 31, 2021, using the following databases: PubMed/MEDLINE, Scopus, Web of Science, and Cochrane Library. Studies that measure the prevalence and risk factors of hypertension among adult cotton textile workers in LMICs were included. Extraction of articles and quality assessment of included studies were performed independently by two authors using the Mixed Methods Appraisal Tool checklist.

RESULTS

Of 2476 titles screened after duplication, 50 studies were shortlisted for full-text review, and a total of 10 studies were included. Of those 10 studies, seven were carried out in India, one in Indonesia, Iraq, and Iran. Using Stata version 6, the pooled prevalence of hypertension among the cotton textile workers was 18.0% (95% confidence interval: 11.0-25.0, random effect model: I² = 97.12%). Classic risk factors, including age, family history of hypertension, alcohol consumption, body mass index, and high waist-to-hip ratio, were recounted, whereas peculiar to the settings, noise level, improper use of earplugs, duration of noise exposure, working duration, and working in weaving section were reported.

CONCLUSION

The limited available evidence indicates a significant prevalence of hypertension among cotton workers in LMICs. In the wave of double burden of non-communicable diseases in developing countries, considering context-specific risk factors is critical in controlling hypertension by prioritizing organizational plans and policies to optimize workers' health.

PROSPERO REGISTRATION NUMBER

CRD42020167175.

Effects of Serving as a State Functionary on Self-Rated Health: Empirical Evidence From China

Purpose

There is a strong link between occupation and self-rated health. Existing research has revealed the effects of occupation on self-rated health outcomes and the corresponding mechanisms. However, there is a lack of research on the effects of state services on self-rated health in China. Therefore, this study focuses on exploring the effects of serving as a state functionary in China on self-rated health to enrich research in related fields.

Method

Based on the data of 14,138 individuals collected from the 2016 China Labour-Force Dynamics Survey, the logit model was used to investigate the effects of serving as a state functionary on self-rated health and the difference in the effects across different populations.

Results

The results show that (1) serving as a state functionary has a significant positive effect on self-rated health; (2) self-rated health of elderly state functionaries is higher than that of younger state functionaries; (3) self-rated health of state functionaries in non-eastern regions is higher than that of state functionaries in eastern regions; and (4) state functionaries with lower education have higher self-rated health than highly-educated state functionaries; (5) Higher self-rated health of state functionaries is achieved primarily through better work time, better work environment and lower relative deprivation.

Conclusion

Serving as a state functionary in China has a significant positive correlation with self-rated health, with differences across populations of state functionaries. This study expands the current literature on the effects of occupation on self-rated health in the context of China.

Long working hours associated with elevated ambulatory blood pressure among female and male white-collar workers over a 2.5-year follow-up

Population-based strategies targeting modifiable risk factors are needed to improve the prevention of hypertension. Long working hours have been linked to high blood pressure (BP), but more longitudinal research is required. The objective of this study was to examine the effect of long working hours (≥41 h/week) on ambulatory BP mean over a 2.5-year follow-up. The effect modification of family responsibilities was also investigated. A repeated longitudinal design was used. Data collection was performed at three-time points over a 2.5-year follow-up among over 2000 white-collar workers. Working hours were self-reported assessed by questionnaire. BP was measured using Spacelabs 90207. The outcomes were systolic and diastolic BP mean. Cross-lagged GEE linear regressions were used to examine whether working hours were associated with BP means at the next measurement time. Women working long hours had a higher diastolic BP mean at follow-up compared to women working regular hours (+1.8 mm Hg (95% CI: 0.5-3.1)). In men, those working long hours had both higher systolic and diastolic BP means increases (systolic: +2.5 mm Hg (95% CI: 0.5-4.4)) and diastolic: +2.3 mm Hg (95% CI: 1.0-3.7)). This association was greater among workers having high family responsibilities. This longitudinal study showed that women and men working long hours had higher BP means when compared those working 35-40 h per week. These findings suggest that strategies that promote work weeks not exceeding 40 h might contribute to the primary prevention of hypertension, especially for workers with high family responsibilities.

The effect of long working hours on developing type 2 diabetes in adults with prediabetes: The Kangbuk Samsung Cohort Study

Background

Long working hours are known to account for approximately one-third of the total expected work-related diseases, and much interest and research on long working hours have recently been conducted. Additionally, as the prevalence of prediabetes and the high-risk group for diabetes are increasing worldwide, interest in prediabetes is also rising. However, few studies have addressed the development of type 2 diabetes and long working hours in prediabetes. Therefore, the aim of this longitudinal study was to evaluate the relationship between long working hours and the development of diabetes in prediabetes.

Methods

We included 14,258 prediabetes participants with hemoglobinA1c (HbA1c) level of 5.7 to 6.4 in the Kangbuk Samsung Cohort Study. According to a self-reported questionnaire, we evaluated weekly working hours, which were categorized into 35–40, 41–52, and > 52 hours. Development of diabetes was defined as an HbA1c level ≥ 6.5%. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the development of diabetes were estimated using Cox proportional hazards analyses with weekly working 35–40 hours as the reference.

Results

During a median follow-up of 3.0 years, 776 participants developed diabetes (incidence density, 1.66 per 100 person-years). Multivariable-adjusted HRs of development of diabetes for weekly working > 52 hours compared with working 35–40 hours were 2.00 (95% CI: 1.50–2.67). In subgroup analyses by age (< 40 years old, ≥ 40 years old), sex (men, women), and household income (< 6 million KRW, ≥ 6 million KRW), consistent and significant positive associations were observed in all groups.

Conclusions

In our large-scale longitudinal study, long working hours increases the risk of developing diabetes in prediabetes patients.

Dose-response relationship between working hours and hypertension: A 22-year follow-up study

Hypertension causes a substantial burden to society. Some studies found that hypertension was associated with the working type and working hours. The purpose of the current study is to assess the dose-response relationship between working hours and hypertension.Data of 12,080 adults aged 18 to 65 years who attended the China Health and Nutrition Survey (CHNS) between 1989 and 2011 were analyzed. Hypertension was determined based on systolic and/or diastolic blood pressure measures, or having doctor-diagnosed hypertension. Multivariable Cox regression and restricted cubic spline to assess the dose-response relationship between working hours and hypertension.A total of 12,080 participants including 5852 females and 6228 males. By the last follow-up (2011), a total of 830 participants were hypertensive, with an incidence of 6.9%. After adjusting socio-demographic, lifestyle factors, as well as occupation type, compared with those who worked 35 to 49 hours per week, participants who worked no more than 34 hours per week (HR: 1.21, 95%CI: 1.03-1.41) and at least 56 hours per week (HR: 1.38, 95%CI: 1.19-1.59) had a higher risk of hypertension. The significant association between long working hours (at least 56 hours per week) and hypertension was observed among females (HR: 1.38, 95%CI: 1.16-1.64) and males (HR: 1.36, 95%CI: 1.04-1.78). Among manual workers, the relationship between long working hours and hypertension was observed (HR: 1.49, 95%CI: 1.10-2.02). The relationship between long working hours (HR: 1.21, 95%CI: 1.01-1.44) and short working hours (HR: 1.37, 95%CI: 1.16-1.61) and hypertension was observed among nonmanual workers. The hazard ratio of hypertension and working time displayed U-shape non-linear relationship (Ptrend < .001, non-linear P < .001). The non-linear response-dose relationship was found in manual worker, nonmanual worker, and male (Ptrend < .001, non-linear P < .001).The association between working time and hypertension showed U-shape relationship. Specifically, overtime work was an important occupational risk factors for adults, and short work time was related to hazard ratio of hypertension in nonmanual workers.

Development, validation and utilisation of dish-based dietary assessment tools: a scoping review

OBJECTIVE

To summarise the existing evidence of development, validation and current status of utilisation of dish-based dietary assessment tools.

DESIGN

Scoping review.

SETTING

Systematic search using PubMed and Web of Science.

RESULTS

We identified twelve tools from seventy-four eligible publications. They were developed for Koreans (n 4), Bangladeshis (n 2), Iranians (n 1), Indians/Malays/Chinese (n 1), Japanese (n 3) and Chinese Americans (n 1). Most tools (10/12) were composed of a dish-based FFQ. Although the development process of a dish list varied among the tools, six studies classified mixed dishes based on the similarity of their characteristics such as food ingredients and cooking methods. Tools were validated against self-reported dietary information (n 9) and concentration biomarkers (n 1). In the eight studies assessing the differences between the tool and a reference, the mean (or median) intake of energy significantly differed in five studies, and 26-83 % of nutrients significantly differed in eight studies. Correlation coefficients for energy ranged from 0·15 to 0·87 across the thirteen studies, and the median correlation coefficients for nutrients ranged from 0·12 to 0·77. Dish-based dietary assessment tools were used in fifty-nine studies mainly to assess diet-disease relationships in target populations.

CONCLUSIONS

Dish-based dietary assessment tools have exclusively been developed and used for Asian-origin populations. Further validation studies, particularly biomarker-based studies, are needed to assess the applicability of tools.

Mortality risks among blue- and white-collar workers: A time series study among Japanese men aged 25-64 years from 1980 to 2015

OBJECTIVE

We aimed to analyse age-standardised mortality trends in Japan among blue- and white-collar male workers aged 25-64 years, by major causes of mortality from 1980 to 2015.

METHODS

Five-yearly mortality data were extracted from occupation-specific vital statistics maintained by the Japanese Ministry of Health, Labour and Welfare. A time series study was conducted among employed men aged 25-64 years. Age-standardised mortality trends by occupational category were calculated separately for all cancers, ischaemic heart disease, cerebrovascular disease and suicide. Poisson regression analysis was performed to analyse mortality trends by occupational category for each cause.

RESULTS

Mortality rates for all cancers and ischaemic heart disease were higher among white-collar workers than blue-collar workers throughout the 35-year study period. The gap in the mortality rates for all four causes of death among blue- and white-collar workers widened in 2000 after Japan's economic bubble burst in the late 1990s. Simultaneously, suicide mortality rates among white-collar workers increased sharply and have remained higher than among blue-collar workers.

CONCLUSIONS

White-collar male workers in Japan have a higher risk of mortality than male blue-collar workers. However, despite substantial differences, significant progress has been made in recent years in reducing mortality across all occupations in Japan.

The prevalence of hypertension and influencing factors among the employees of a university hospital

Background

Hypertension is a serious disease with increasing worldwide prevalence, leading to life-threatening complications.

Methods

This cross-sectional study was carried out in a university hospital. The Occupational Health and Safety Unit data concerning the health examinations of employees were used to determine the prevalence of hypertension in a university hospital and to define the relationship between hypertension and sociodemographic and occupational parameters. Logistic regression analyses were performed for the variables having a significant association with high blood pressure.

Results

The data generated during the periodic examination of 3,480 (92%) of all employees (3,780) were analyzed. The prevalence of hypertension was 14.8%. The prevalence of hypertension was found to be 13.5%, 13.9%, and 23.7% among physicians, non-physician healthcare personnel and officers respectively. The logistic regression model revealed a statistically significant correlation between hypertension and male gender, age and BMI.

Conclusion

The prevalence of hypertension was highest among staff members. Special programs would facilitate the diagnosis, control, and prevention of high blood pressure among the high-risk groups, especially men, the elderly and the obese hospital employees.

The relationship between long working hours and weight gain in older workers in Europe

BACKGROUND: Several studies have been performed on the relationship between working conditions and health. Numerous parameters still require further study, including working hours and obesity among different groups, specifically older workers in national, regional, and international levels. OBJECTIVE: Working hours have considerable effects on the socio-cultural, psychological, and economic aspects of people’s lives and health. While long working hours increases income level and raises living standards, it increases the risk of certain health problems. This study investigated whether working hours are associated with obesity in upper-middle-aged workers. METHODS: The Survey of Health, Ageing and Retirement in Europe (SHARE) dataset was used for the analyses. Analyses were carried out by means of a Cox regression of the panel dataset created with the data in question, surveyed by European Commission to 12,000 participants. RESULTS: The survey was performed in Austria, Belgium, Switzerland, Germany, Denmark, Spain, France, Greece, Italy, the Netherlands, Sweden, the Czech Republic, Poland, and Ireland. We found that in most countries, especially Sweden and the Netherlands, upper-middle-aged employees working > 59 hours per week are more likely to gain weight than their counterparts working < 59 hours. CONCLUSIONS: Our findings raise awareness of obesity in older workers, and highlight the need to regulate working conditions and hours in the European Union and other countries.

Long Working Hours and the Prevalence of Masked and Sustained Hypertension

Previous studies on the effect of long working hours on blood pressure have shown inconsistent results. Mixed findings could be attributable to limitations related to blood pressure measurement and the lack of consideration of masked hypertension. The objective was to determine whether individuals who work long hours have a higher prevalence of masked and sustained hypertension. Data were collected at 3-time points over 5 years from 3547 white-collar workers. Long working hours were self-reported, and blood pressure was measured using Spacelabs 90207. Workplace clinic blood pressure was defined as the mean of the first 3readings taken at rest at the workplace. Ambulatory blood pressure was defined as the mean of the next readings recorded every 15 minutes during daytime working hours. Masked hypertension was defined as clinic blood pressure < 140/90 mm Hg and ambulatory blood pressure ≥135/85 mm Hg. Sustained hypertension was defined as clinic blood pressure ≥140/90 mm Hg and ambulatory blood pressure ≥135/85 mm Hg or being treated hypertension. Long working hours were associated with the prevalence of masked hypertension (prevalence ratio 49+ =1.70 [95% CI, 1.09–2.64]), after adjustment for sociodemographics, lifestyle-related risk factors, diabetes mellitus, family history of cardiovascular disease, and job strain. The association with sustained hypertension was of a comparable magnitude (prevalence ratio 49+ =1.66 [95% CI, 1.15–2.50]). Results suggest that long working hours are an independent risk factor for masked and sustained hypertension. Workplace strategies targeting long working hours could be effective in reducing the clinical and public health burden of hypertension.

Effect of Obesity and Other Risk Factors on Hypertension among Women of Reproductive Age in Ghana: An Instrumental Variable Probit Model

Background: The growing incidence of mortality as a result cardiovascular diseases (CVDs) is a major public health concern in several developing countries. In Ghana, unhealthy food consumption pattern and sedentary lifestyle are promoting overweight and obesity, with significant consequences on the incidence of CVDs. Specifically, hypertension morbidity is now a public health concern among Ghanaian health policy makers. This paper analysed the effect of body mass index (BMI)/arm circumference and other associated factors on hypertension risk among women of reproductive ages in Ghana. Methods: The data were collected as Demographic and Health Survey (DHS) in 2014. This paper analysed the subset of the data that were collected from eligible women 15-49 years of age. The total sample was 9396, while 9367 gave consents to have their blood pressure measured. Data were analysed with instrumental probit regression model with consideration of potential endogeneity of BMI and arm circumference. Results: The results showed that 25% of the women were either overweight or obese, while 13.28% were hypertensive. Women from the Greater Accra (18.15%), Ashanti (15.53%) and Volta (15.02%) regions had the highest incidences of hypertension. BMI and arm circumferences were truly endogenous and positively associated with the probability of being hypertensive. Other factors that influenced hypertension were age of women, region of residence, urban/rural residence, being pregnant, access to medical insurance, currently working, consumption of broth cubes, processed can meats, salted meat and fruits. Conclusion: It was concluded that hypertension risk was positively associated with being overweight, obesity, age and consumption of salted meat.It was inter aliaemphasized that engagement in healthy eating with less consumption of salted meats, and more consumption of fruits would assist in controlling hypertension among Ghanaian women.

The Effect of Long Working Hours and Overtime on Occupational Health: A Meta-Analysis of Evidence from 1998 to 2018

There has been no subsequent meta-analysis examining the effects of long working hours on health or occupational health since 1997. Therefore, this paper aims to conduct a meta-analysis covering studies after 1997 for a comparison. A total of 243 published records were extracted from electronic databases. The effects were measured by five conditions, namely, physiological health (PH), mental health (MH), health behaviours (HB), related health (RH), and nonspecified health (NH). The overall odds ratio between long working hours and occupational health was 1.245 (95% confidence interval (CI): 1.195-1.298). The condition of related health constituted the highest odds ratio value (1.465, 95% CI: 1.332-1.611). The potential moderators were study method, cut-point for long weekly working hours, and country of origin. Long working hours were shown to adversely affect the occupational health of workers. The management on safeguarding the occupational health of workers working long hours should be reinforced.

The association between long working hours and work-related musculoskeletal symptoms of Korean wage workers: data from the fourth Korean working conditions survey (a cross-sectional study)

Background

It has been reported that long working hours are hazardous to the workers’ health. Especially, work-related musculoskeletal disorders (WMSDs) have been considered as one of the significant health issues in workplace. The objective of this study was to identify the association between long working hours and work-related musculoskeletal symptoms.

Methods

The analysis was conducted using data from the Fourth Korean Working Conditions Survey (KWCS). Subjects of this study were 24,783 wage workers and divided into three groups according to the weekly working hours, which were ≤ 40, 41–52 and > 52 h. The relationship between long working hours and work-related musculoskeletal symptoms was analyzed by multivariate logistic regression method after adjusting for general, occupational characteristics including specific working motions or postures and psychosocial factors.

Results

Approximately 18.4% of subjects worked more than 52 h per week and 26.4 and 16.4% of male subjects and 33.0 and 23.4% of female subjects experienced work-related upper and lower limb pains, respectively, over the last 12 months. Moreover, the prevalence of upper and lower limb pain was increased in both genders as the weekly working hours increased. The odds ratios (ORs) of upper limb pain for those working 41–52 h and more than 52 h per week when adjusted for general, occupational characteristics including specific motions or postures and psychosocial factors were 1.36 and 1.40 for male workers and 1.26 and 1.66 for female workers compared to the reference group, respectively. Furthermore, ORs of lower limb pain for the same weekly working hour groups were 1.26 and 1.47 for male workers and 1.20 and 1.47 for female workers, respectively.

Conclusions

Long working hours were significantly related to work-related musculoskeletal symptoms in Korean wage workers and appropriate interventions should be implemented to reduce long working hours that can negatively affect workers’ health.

Impact of occupational environmental stressors on blood pressure changes and on incident cases of hypertension: a 5-year follow-up from the VISAT study

BACKGROUND

The role of occupational stressors (OS) on blood pressure (BP) is often suspected, but asserting its impact remains uncertain. Our goal was to evaluate their impact on BP increase and on incident cases of hypertension over a 5-year period.

METHODS

One thousand, one hundred and fifty-six men and women from the French prospective VISAT study were followed up over five-years (T1 to T2). Exposures to a large panel of OS (physical, organizational, psychosocial and employment categories) were collected. Linear and logistic regressions were used to assess associations between OS and T2-T1 SBP difference and incident cases of hypertension. They were performed to determine the role of OS first considered separately, then in combination, in crude and adjusted models for main cardiovascular risk factors (gender, age, education, BMI, lifestyle habits and medical history).

RESULTS

For initial SBP level < 130 mmHg, carrying loads, intense noise exposure, working more than 48 h/week, active and high strain tended to be associated with an SBP difference increase, while job recognition was associated with a decrease. After adjustment, only significant associations with job strain and job recognition persisted. For initial SBP level ≥ 130 mmHg, being exposed to an active job strain was positively associated with T2-T1 SBP difference only in unadjusted model. Considering all the OS, the recognition of completed tasks had a major protective role. No impact of OS on incident cases of hypertension was observed.

CONCLUSION

Associations between OS and SBP were observed mainly when initial SBP is within the normal range, and are mainly explained by cardiovascular factors, requiring physician's particular attention to people exposed to these OS. VISAT study is registered in "LE PORTAIL EPIDEMIOLOGIE - FRANCE- AVIESAN -ID 3666".

Hemodynamic Responses to Simulated Long Working Hours with Short and Long Breaks in Healthy Men

This study aimed to examine hemodynamic responses and the necessity of breaks under long working hours. Thirty-eight healthy males conducted PC-based work from 9:10 to 22:00. Nine 10-minute short breaks and two long breaks (a 1-hour break and a 50-minute break) were provided, and hemodynamic responses were measured regularly during this period. The results showed that systolic blood pressure increased during the working hours and cardiovascular burden increased under long working hours. Cardiac responses decreased, but vascular responses increased continually during work periods without long breaks. The long breaks, however, benefitted workers by preventing excessive decreases in cardiac responses and increases in vascular responses, but this effect may decrease with the extension of working hours. In conclusion, long working hours increase cardiovascular burden, and taking long breaks is important for reducing these burdens when long working hours cannot be avoided.

Long weekly working hours and ischaemic heart disease: a follow-up study among 145 861 randomly selected workers in Denmark

OBJECTIVES

The aim of the present study was to test if incidences of ischaemic heart disease (IHD) and usage of antihypertensive drugs are independent of weekly working hours (WWH) among full-time employees in Denmark.

DESIGN AND PARTICIPANTS

Data on WWH from participants of the Danish labour force surveys, 1999-2013, were linked on an individual level to national registers with data on socioeconomic status (SES), industry, emigrations, redeemed prescriptions, hospital contacts and deaths. Participants were followed until the end of 2014 (on average 7.7 years). Poisson regression was used to model incidence rates as a function of WWH. The analyses were controlled for calendar time, time passed since start of follow-up, employment in the healthcare industry, age, sex, SES and night work.

RESULTS

In total, we found 3635 cases of IHD and 20 648 cases of antihypertensive drug usage. The rate ratio of IHD was 0.95 (95% CI 0.85 to 1.06) for 41-48 compared with 32-40 WWH and 1.07 (0.94 to 1.21) for >48 compared with 32-40 WWH. The corresponding rate ratios for antihypertensive drug usage were 0.99 (0.95 to 1.04) and 1.02 (0.97 to 1.08). No statistically significant interactions between WWH and sex, SES and night work, respectively, were found.

CONCLUSION

In this Danish sample, we did not find any statistically significant association between WWH and IHD or antihypertensive drug usage.

Chronic Disease Risks From Exposure to Long-Hour Work Schedules Over a 32-Year Period

OBJECTIVES

This study aims at evaluating the chronic disease risk related to prolonged work in long-hour schedules for eight major chronic diseases: heart disease, non-skin cancer, arthritis, diabetes, chronic lung disease, asthma, chronic depression, and hypertension.

METHODS

The study used data from the National Longitudinal Survey of Youth, 1979 covering 32 years of job history (1978 to 2009) for 7492 respondents. Logistic regression analyses were performed to test the relationship between average weekly work hours, and the reported prevalence of those conditions for each individual.

RESULTS

Regularly working long hours over 32 years was significantly associated with elevated risks of heart disease, non-skin cancer, arthritis, and diabetes. The observed risk was much larger among women than among men.

CONCLUSIONS

Working long-hour schedules over many years increases the risk for some specific chronic diseases, especially for women.

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.

Validity and reproducibility of self-reported working hours among Japanese male employees

OBJECTIVE

Working long hours is a potential health hazard. Although self-reporting of working hours in various time frames has been used in epidemiologic studies, its validity is unclear. The objective of this study was to examine the validity and reproducibility of self-reported working hours among Japanese male employees.

METHODS

The participants were 164 male employees of four large-scale companies in Japan. For validity, the Spearman correlation between self-reported working hours in the second survey and the working hours recorded by the company was calculated for the following four time frames: daily working hours, monthly overtime working hours in the last month, average overtime working hours in the last 3 months, and the frequency of long working months (≥45 h/month) within the last 12 months. For reproducibility, the intraclass correlation between the first (September 2013) and second surveys (December 2013) was calculated for each of the four time frames.

RESULTS

The Spearman correlations between self-reported working hours and those based on company records were 0.74, 0.81, 0.85, and 0.89 for daily, monthly, 3-monthly, and yearly time periods, respectively. The intraclass correlations for self-reported working hours between the two questionnaire surveys were 0.63, 0.66, 0.73, and 0.87 for the respective time frames.

CONCLUSIONS

The results of the present study among Japanese male employees suggest that the validity of self-reported working hours is high for all four time frames, whereas the reproducibility is moderate to high.

Depression, anxiety, stress and demographic determinants of hypertension disease

Background and Objective: Research evidence supports the relationship of psychological and demographic factors with hypertension and these variables are strongest predictors of hypertension which are scarcely studied in Pakistan. The present study was carried out to explore the correlation of depression, anxiety, stress and demographic factors with hypertension.

Method: We used correlation research design and a sample of (N = 237), hypertensive patients (N = 137) and their age matched healthy controls (N = 100) was taken from hospitals. Depression, Anxiety and Stress Scale (DASS) (Lovibond & Lovibond, 1995) was used to assess depression, anxiety and stress.

Results: Results indicated significant positive correlation between depression (χ²_MH = 104.18, p < .001), anxiety (χ²_MH = 78.48, p < .001), stress (χ²_MH = 110.95, p < .001) and overall negative states (χ²_MH = 97.43, p < .001) with hypertension. Depression (OR = 1.44, p < .01), anxiety (OR = 1. 76, p < .01) stress (OR = 1.37, p < .01), job and dependents, working hours and weight turned out as predictors of hypertension.

Conclusion: Hypertension has significant positive relationship with depression, anxiety, stress and with demographic variables. The findings of the present study will contribute in the existing knowledge of health professionals to enhance public awareness regarding the harmful outcomes of depression, anxiety and stress upon human health.

Working overtime and risk factors for coronary heart disease: a propensity score analysis based in the J-SHINE (Japanese Study of Stratification, Health, Income, and Neighborhood) study

BACKGROUND

Evidence on the causal relationship between working overtime and the risk of coronary heart disease is limited.

METHODS

We surveyed 2355 workers in Japan and conducted propensity-matched logistic regression analysis, using propensity-matched 438 pairs, to evaluate the associations between working overtime (more than 50 hr per week) and coronary risk factors: physical inactivity, cigarette smoking, sleep deprivation (<5 hr/day), psychological stress, overweight/obesity, and excessive alcohol consumption. The exposure and outcomes were self-reported.

RESULTS

Among 2355 workers, 476 participants worked overtime. Propensity-matched analysis revealed that the associations between working overtime and sleep deprivation (odds ratios (OR) and 95% confidence intervals: 2.33, 1.39-3.88) and high stress (2.13, 1.60-2.82). The associations between working overtime and physical inactivity, current smoking, and overweight/obesity were not statistically significant. Excessive alcohol consumption was inversely associated with working overtime.

CONCLUSIONS

Working overtime was positively associated with two coronary risk factors: sleep deprivation and increased psychological stress.

Long working hours may increase risk of coronary heart disease

OBJECTIVE

To evaluate the association between long working hours and risk of coronary heart disease (CHD) estimated by Framingham risk score (FRS) in Korean adults.

METHODS

This study evaluated adult participants in Korean National Health and Nutrition Examination Survey IV (2007-2009). After inclusion and exclusion criteria were applied, the final sample size for this study model was 8,350. Subjects were asked about working hours and health status. Participants also completed physical examinations and biochemical measurement necessary for estimation of FRS. Multiple logistic regression was conducted to investigate the association between working hours and 10-year risk for CHD estimated by FRS.

RESULTS

Compared to those who work 31-40 hr, significantly higher 10-year risk was estimated among subjects working longer hours. As working hours increased, odds ratio (OR) for upper 10 percent of estimated 10-year risk for CHD was increased up to 1.94.

CONCLUSIONS

Long working hours are significantly related to risk of coronary heart disease.

Association of overtime work and hypertension in a Japanese working population: a cross-sectional study

Long working hours have been associated with an increased risk of cardiovascular disease, but its relationship with hypertension remains unclear. The objective of this study is to examine the relationship between overtime and presence of hypertension using data from a large-scale multi-company study in Japan. Participants were 52 365 workers of four companies that provided both health-checkup data and self-reported data on overtime worked. Hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, and/or the use of antihypertensive drug. Logistic regression analysis was performed to determine the odds ratio for hypertension for each category of overtime work (<45, 45-79, 80-99 or ≥100 h/month) with adjustments for age, sex, company, smoking status and body mass index. The prevalence of hypertension tended to decrease with increasing overtime work: 17.5, 12.0, 11.1 and 9.1% for the shortest (<45 h/month) through the longest overtime category (≥100 h/month). The age-, sex- and company-adjusted odds ratios (95% confidence interval) were 1.00 (reference), 0.81 (0.75-0.86), 0.73 (0.62-0.86), 0.58 (0.44-0.76), respectively (p for linear trend <0.001). In a sub-cohort, the inverse association remained statistically significant after an additional adjustment for other potential confounders. Results of the present large-scale study among Japanese workers suggest an inverse association between overtime work and presence of hypertension.

Effect of Long Working Hours on Self-reported Hypertension among Middle-aged and Older Wage Workers

Objectives

Many studies have reported an association between overwork and hypertension. However, research on the health effects of long working hours has yielded inconclusive results. The objective of this study was to identify an association between overtime work and hypertension in wage workers 45 years and over of age using prospective data.

Methods

Wage workers in Korea aged 45 years and over were selected for inclusion in this study from among 10,254 subjects from the Korean Longitudinal Study of Ageing. Workers with baseline hypertension and those with other major diseases were excluded. In the end, a total of 1,079 subjects were included. A Cox proportional hazards model was used to calculate hazard ratios and adjust for baseline characteristics such as sex, age, education, income, occupation, form of employment, body mass index, alcohol habit, smoking habit, regular exercise, and number of working days per week. Additional models were used to calculate hazard ratios after gender stratification.

Results

Among the 1,079 subjects, 85 workers were diagnosed with hypertension during 3974.2 person-months. The average number of working hours per week for all subjects was 47.68. The proportion of overtime workers was 61.0% (cutoff, 40 h per week). Compared with those working 40 h and less per week, the hazard ratio of subjects in the final model, which adjusted for all selected variables, working 41-50 h per week was 2.20 (95% confidence interval [CI], 1.19–4.06), that of subjects working 51-60 h per week was 2.40 (95% CI, 1.07–5.39), and that of subjects working 61 h and over per week was 2.87 (95% CI, 1.33–6.20). In gender stratification models, the hazard ratio of the females tended to be higher than that of the males.

Conclusion

As the number of working hours per week increased, the hazard ratio for diagnosis of hypertension significantly increased. This result suggests a positive association between overtime work and the risk of hypertension.

Workplace psychosocial factors associated with hypertension in the U.S. workforce: a cross-sectional study based on the 2010 national health interview survey

OBJECTIVE

To explore associations between self-reported hypertension and workplace psychosocial factors that are common among U.S. workers and to identify industries and occupations (I&Os) that are associated with a high prevalence of hypertension, even after adjustment for common known risk factors.

METHODS

Data from the 2010 National Health Interview Survey were used to examine relationships between the prevalence of self-reported hypertension and job insecurity, hostile work environment, work- family imbalance, work hours and I&O.

RESULTS

Job insecurity (adjusted prevalence ratio (aPR): 1.11; 95% confidence interval (CI): 1.04-1.19)) and hostile work environment (aPR: 1.15; 95% CI: 1.03-1.29) were significantly associated with hypertension. Hypertension prevalence was significantly elevated among those employed in Healthcare Support occupations and Public Administration industries.

CONCLUSION

Addressing hostile work environments and the stress associated with job insecurity may improve workers' health. Other occupational factors that contribute to the variation in prevalence of hypertension by I&O should be sought.

Is hypertension associated with job strain? A meta-analysis of observational studies

Job strain results from a combination of high workload and few decision-making opportunities in the workplace. There is inconsistent evidence regarding the association between job strain and hypertension, and methodological shortcomings preclude firm conclusions. Thus, a meta-analysis of observational studies on hypertension among occupational groups was conducted to determine whether job strain was associated with hypertension. In January 2012, we carried out a comprehensive, topic-specific electronic literature search of the Ovid MEDLINE, EMBASE and PsychoINFO databases complemented by individual help from non-communicable disease experts. Experimental/interventional studies and studies on personality disorders were excluded. Nine of 894 identified studies met the eligibility criteria and were included in the meta-analysis. The pooled OR of the nine studies was 1.3 (95% CI 1.14 to 1.48; p<0.001), of case-control studies 3.17 (95% CI 1.79 to 5.60; p<0.001) and of cohort studies 1.24 (95% CI 1.09 to 1.41; p<0.001), all of which indicated statistically significant positive associations between job strain and hypertension. In a subgroup analysis, cohort studies of good methodological quality showed significant associations between job strain and hypertension, while those of poor methodological quality showed no association or subgroup differences. We conclude that despite methodological differences, case-control and cohort studies of good methodological quality showed positive associations between hypertension and job strain.

A Research Note on the Relationship Between Long Working Hours and Weight Gain for Older Workers in the United States

Working long hours may be related to obesity in older adults. No studies have focused on older workers and long work hours, although the risk of obesity is high among this population group. This study is the first attempt to investigate the relationship between obesity and the older workforce. Panel data from the Health and Retirement Study are examined using Cox regression techniques. We found that older workers who work more than 59 hr a week are more likely to gain weight than older workers who work less than 59 hr per week.

Is hypertension associated with job strain? A meta-analysis of observational studies

Job strain results from a combination of high workload and few decision-making opportunities in the workplace. There is inconsistent evidence regarding the association between job strain and hypertension, and methodological shortcomings preclude firm conclusions. Thus, a meta-analysis of observational studies on hypertension among occupational groups was conducted to determine whether job strain was associated with hypertension. In January 2012, we carried out a comprehensive, topic-specific electronic literature search of the Ovid MEDLINE, EMBASE and PsychoINFO databases complemented by individual help from non-communicable disease experts. Experimental/interventional studies and studies on personality disorders were excluded. Nine of 894 identified studies met the eligibility criteria and were included in the meta-analysis. The pooled OR of the nine studies was 1.29 (95% CI 1.14 to 1.47; p<0.001), of case–control studies 2.88 (95% CI 1.63 to 5.09; p<0.001) and of cohort studies 1.24 (95% CI1.09 to 1.41; p<0.001), all of which indicated statistically significant positive associations between job strain and hypertension [corrected]. In a subgroup analysis, cohort studies of good methodological quality showed significant associations between job strain and hypertension, while those of poor methodological quality showed no association or subgroup differences. We conclude that despite methodological differences, case-control and cohort studies of good methodological quality showed positive associations between hypertension and job strain.

Disability rates for cardiovascular and psychological disorders among autoworkers by job category, facility type, and facility overtime hours

BACKGROUND

We examined the association between long work hours, assembly line work and stress-related diseases utilizing objective health and employment data from an employer's administrative databases.

METHODS

A North American automobile manufacturing company provided data for claims for sickness, accident and disability insurance (work absence of at least 4 days) for cardiovascular disease (CVD), hypertension and psychological disorders, employee demographics, and facility hours worked per year for 1996-2001. Age-adjusted claim rates and age-adjusted rate ratios were calculated using Poisson regression, except for comparisons between production and skilled trades workers owing to lack of age denominator data by job category. Associations between overtime hours and claim rates by facility were examined by Poisson regression and multi-level Poisson regression.

RESULTS

Claims for hypertension, coronary heart disease, CVD, and psychological disorders were associated with facility overtime hours. We estimate that a facility with 10 more overtime hours per week than another facility would have 4.36 more claims for psychological disorders, 2.33 more claims for CVD, and 3.29 more claims for hypertension per 1,000 employees per year. Assembly plants had the highest rates of claims for most conditions. Production workers tended to have higher rates of claims than skilled trades workers.

CONCLUSIONS

Data from an auto manufacturer's administrative databases suggest that autoworkers working long hours, and assembly-line workers relative to skilled trades workers or workers in non-assembly facilities, have a higher risk of hypertension, CVD, and psychological disorders. Occupational disease surveillance and disease prevention programs need to fully utilize such administrative data.

Excessive work and risk of haemorrhagic stroke: a nationwide case-control study

BACKGROUND

Adverse effect of excessive work on health has been suggested previously, but it was not documented in cerebrovascular diseases.

AIM

The authors investigated whether excessive working conditions would associate with increased risk of haemorrhagic stroke.

METHODS

A nationwide matched case-control study database, which contains 940 cases of incident haemorrhagic stroke (498 intracerebral haemorrhages and 442 sub-arachnoid haemorrhages) with 1880 gender- and age- (± 5-year) matched controls, was analysed. Work-related information based on the regular job situation, including type of occupation, regular working time, duration of strenuous activity during regular work and shift work, was gathered through face-to-face interviews. Conditional logistic regression analyses were used for the multivariable analyses.

RESULTS

Compared with white-collar workers, blue-collar workers had a higher risk for haemorrhagic stroke (odds ratio, 1.33 [95% confidence interval, 1.06-1.66]). Longer regular working time was associated with increased risk of haemorrhagic stroke [odds ratio, 1.38 (95% confidence interval, 1.05-1.81) for 8-12 h/day; odds ratio, 1.95 (95% confidence interval, 1.33-2.86) for ≥ 13 h/day; compared with ≤ 4 h/day]. Exposure to ≥ 8 h/week of strenuous activity also associated haemorrhagic stroke risk [odds ratio, 1.61 (95% confidence interval, 1.26-2.05); compared with no strenuous activity]. Shift work was not associated with haemorrhagic stroke (P = 0.98). Positive associations between working condition indices and haemorrhagic stroke risk were consistent regardless of haemorrhagic stroke sub-types and current employment status.

CONCLUSIONS

Blue-collar occupation, longer regular working time and extended duration of strenuous activity during work may relate to an increased risk of haemorrhagic stroke.

Associations of work hours and actual availability of weekly rest days with cardiovascular risk factors

OBJECTIVES

The aim of study was to determine the associations of work hours and actual availability of weekly rest days with the onset of lifestyle-related diseases such as obesity, hypertension, hypertriglyceridemia, low levels of high-density lipoprotein (HDL) cholesterol and hyperglycemia.

METHODS

For this longitudinal study, we used data from checkups conducted in 1999 and 2006 for 30,194 men who worked for a local public institution in Japan. We calculated the cumulative incidence rates of onset of obesity, hypertension, hyperglycemia, hypertriglyceridemia and low HDL cholesterol over this 7-year period and performed a χ2 test to determine the association between the above diseases and work conditions (work hours and actual availability of weekly rest days) at the time of the baseline survey. We then performed multiple logistic regression analysis of the diseases that showed significant associations.

RESULTS

The adjusted odds ratio for the onset of hypertriglyceridemia in subjects who worked ≥9 hours was high (1.11 [95% CI: 1.02-1.22], p=0.02) in comparison with those who worked <9 hours. The adjusted odds ratio for the onset of hypertriglyceridemia in subjects who could not often take weekly rest days was high (1.13 [95% CI: 1.01-1.27], p=0.03) in comparison with those who were able to take most of the available weekly rest days off work.

CONCLUSIONS

These results show that work hours and actual availability of weekly rest days independently predict the onset of hypertriglyceridemia. Working only regular hours and taking advantage of weekly rest days can contribute to the prevention of hypertriglyceridemia.

Long working hours and coronary heart disease: a systematic review and meta-analysis

The authors aggregated the results of observational studies examining the association between long working hours and coronary heart disease (CHD). Data sources used were MEDLINE (through January 19, 2011) and Web of Science (through March 14, 2011). Two investigators independently extracted results from eligible studies. Heterogeneity between the studies was assessed using the I² statistic, and the possibility of publication bias was assessed using the funnel plot and Egger's test for small-study effects. Twelve studies were identified (7 case-control, 4 prospective, and 1 cross-sectional). For a total of 22,518 participants (2,313 CHD cases), the minimally adjusted relative risk of CHD for long working hours was 1.80 (95% confidence interval (CI): 1.42, 2.29), and in the maximally (multivariate-) adjusted analysis the relative risk was 1.59 (95% CI: 1.23, 2.07). The 4 prospective studies produced a relative risk of 1.39 (95% CI: 1.12, 1.72), while the corresponding relative risk in the 7 case-control studies was 2.43 (95% CI: 1.81, 3.26). Little evidence of publication bias but relatively large heterogeneity was observed. Studies varied in size, design, measurement of exposure and outcome, and adjustments. In conclusion, results from prospective observational studies suggest an approximately 40% excess risk of CHD in employees working long hours.

Overtime work and blood pressure in normotensive Japanese male workers

BACKGROUND

Epidemiological studies have observed conflicting patterns as to whether overtime work increases blood pressure (BP), probably as a consequence of methodological issues.

METHODS

We conducted a prospective cohort study to investigate the relationship between overtime work hours and 1-year changes in BP in 1,235 normotensive Japanese male workers who carried out a variety of jobs in a manufacturing factory. Casual BP measurements were repeated at annual health examinations in 2004-2005, using an automatic manometer. An analysis of covariance that incorporated potential confounding factors including baseline age, body mass index (BMI), and lifestyle factors was used to calculate and compare the means of the 1-year change in systolic (SBP) and diastolic BP (DBP). The participants were grouped according to their average monthly overtime work hours obtained from timecard data between April and September 2004.

RESULTS

The multivariate-adjusted mean for 1-year change in DBP in 611 male assembly-line workers was 1.5 mm Hg (95% confidence interval (CI) 0.8-2.2) for <40.0 h/month, 2.3 mm Hg (95% CI 1.3-3.2) for 40.0-79.9 h/month, and 5.3 mm Hg (95% CI 2.7-7.9) for ≥ 80.0 h/month (P for heterogeneity = 0.02). A broadly similar pattern was observed for SBP. In contrast, there was no significant difference in means 1-year change for both SBP and DBP in 315 clerks and 309 engineers/special technicians, grouped according to overtime work hours.

CONCLUSIONS

Extensive overtime work was associated with increased BP in normotensive male assembly-line workers, but not in clerks and engineers/special technicians.

Headache prevalence and long working hours: the role of physical inactivity

OBJECTIVES

Headaches and long working hours are important issues for workers. This study investigated the association between hours worked and the prevalence of headaches, and how that association varies with physical activity.

STUDY DESIGN

Cross-sectional study with two-stage cluster sampling.

METHODS

Using data from a nationally representative sample of households in Japan, people aged 20-65 years who worked ≥35 h/week were studied, and the cross-sectional association between the number of hours worked per week (35-45, 46-55 and >55 h/week) and the prevalence rates of headaches of different severity was evaluated.

RESULTS

Of 721 workers, 307 reported experiencing at least one headache per month. Compared with working 35-45 h/week, the prevalence ratios of severe or disabling headaches among individuals working >55 h/week were 1.38 [95% confidence interval (CI) 1.06-1.78] and 1.63 (95% CI 1.09-2.43), respectively. After stratification by the level of physical activity, the prevalence ratios were greater in the low-physical-activity group: 1.56 (95% CI 1.11-2.19) for severe headaches and 2.20 (95% CI 1.31-3.68) for disabling headaches. The number of hours worked was not associated with headaches in the high-physical-activity group.

CONCLUSIONS

Among workers in the general population, long working hours were associated with the prevalence of headaches, and the association may depend on a lack of physical activity.

Long working hours and metabolic syndrome among Japanese men: a cross-sectional study

Background

The link between long working hours and health has been extensively studied for decades. Despite global concern regarding metabolic syndrome, however, no studies to date have solely evaluated the relationship between long working hours and that syndrome. We therefore examined the association between long working hours and metabolic syndrome in a cross-sectional study.

Methods

Between May and October 2009, we collected data from annual health checkups and questionnaires from employees at a manufacturing company in Shizuoka, Japan. Questionnaires were returned by 1,601 workers (response rate: 96.2%; 1,314 men, 287 women). After exclusions, including women because of a lack of overtime work, the analysis was performed for 933 men. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for metabolic syndrome. Further, we conducted a stratified analysis by age-group (<40 years vs. ≥40 years).

Results

Metabolic syndrome was identified in 110 workers (11.8%). We observed a positive association between working hours and metabolic syndrome after adjusting for age, occupation, shift work, smoking status, frequency of alcohol consumption, and cohabiting status. Compared with subjects who worked 7–8 h/day, multivariate ORs for metabolic syndrome were 1.66 (95% CI, 0.91–3.01), 1.48 (95% CI, 0.75–2.90), and 2.32 (95% CI, 1.04–5.16) for those working 8–9 h/day, 9–10 h/day, and >10 h/day, respectively. Similar patterns were obtained when we excluded shift workers from the analysis. In age-stratified analysis, the corresponding ORs among workers aged ≥40 years were 2.02 (95% CI, 1.04–3.90), 1.21 (95% CI, 0.53–2.77), and 3.14 (95% CI, 1.24–7.95). In contrast, no clear association was found among workers aged <40 years.

Conclusions

The present study suggests that 10 h/day may be a trigger level of working hours for increased risk of metabolic syndrome among Japanese male workers.

Work-related cardiovascular disease risk factors using a socioecological approach: implications for practice and research

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of mortality. Numerous investigations have linked occupational factors and CVD. Occupational factors such as overtime work have an enormous effect on the CVD risk of industrial workers. However, risk factors for CVD are not systematically reviewed in the workplace. The purpose of the paper is to review work-related risk factors for CVD.

METHODS

A systematic review of work-related CVD risk factors was performed, yielding 180 articles. All articles were assessed in relation to inclusion and exclusion criteria, resulting in 44 articles being reviewed. The sole inclusion criteria was work-related environmental factors and intra/inter-personal factors (psychosocial factors), which is based on the socioecological perspective. The articles were also assessed regarding the quality of each study using the scoring methods developed by Cesario et al. and Brown et al.

CONCLUSION

The literature review demonstrated that work environment factors such as shift work, overtime work, and noise and chemical exposures; and psychosocial factors such as job stress, social support, and socioeconomic status cannot be explained or intervened by one single risk factor. Furthermore, certain occupational factors were shown to aggravate or attenuate other risk factors. The implication of these findings is to incorporate work-related environmental and psychosocial factors into assessment of the patient's CVD risks and intervention plan. Future research should also incorporate a well-defined conceptual framework to address the effects of work-related environmental and psychosocial factors on CVD among CVD patients.

The recognition of occupational diseases attributed to heavy workloads: experiences in Japan, Korea, and Taiwan

OBJECTIVE

Health problems caused by long working hours and work stress have gained growing concerns in Japan, Korea, and Taiwan. In all the three countries, cardiovascular, cerebrovascular, and mental disorders attributed to heavy workloads or stressful work events are considered compensable occupational diseases by workers' compensation systems. This study compared the trends of such cases and correlated the trends with changes in working hours during the period from 1980 to 2010.

METHODS

Data on occupational diseases were obtained from official statistics of the workers' compensation systems. Information on working hours was obtained from official statistics and national surveys of employees.

RESULTS

While occupational cardiovascular, cerebrovascular, and mental disorders attributed to work stress were increasingly compensated in all the three countries, the averaged working hours and the percentage of employees with long working hours had been in decline discordantly.

CONCLUSION

Findings of this study suggested that reducing working hours alone is unlikely to reduce the problems of work stress. There is an urgent need to monitor and regulate a wider range of psychosocial work hazards. Especially, precarious employment and its associated health risks should be targeted for effective prevention of stress-related health problems in the workplace.