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

Metabolic and Obesity Phenotype Trajectories in Taiwanese Medical Personnel

The distribution of metabolic and obesity phenotypes in Taiwanese medical personnel is unknown. In this study, trajectory analysis with repeated measurements was used to explore the development and associated risk factors of different metabolic and obesity phenotypes in hospital staff from a Taiwanese medical center. The results demonstrated that metabolically unhealthy workers presented with a higher body mass index (BMI) compared with their metabolically healthy counterparts. Male and aged > 40 years hospital workers were more likely to be in a deleterious metabolic/obesity state. Meanwhile, profession and working hours were not significantly associated with the development of certain phenotypes in our study. These results shed light on the necessity of adequate data retrieval regarding working hours, and a nuanced examination of working conditions among different professions. Our findings are helpful for the development of advanced guidance regarding health promotion in hospital workers.

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.

Stressors and level of stress among different nursing positions and the associations with hyperlipidemia, hyperglycemia, and hypertension: a national questionnaire survey

BACKGROUND

Nurses are faced with varying job stressors depending on their positions and duties. Few previous studies have compared job stress and related chronic conditions among different nursing positions. The objectives were to compare job stressors among clinical registered nurses, nurse practitioners, and head nurses and explore the impact of job stressors and stress level on hyperlipidemia, hyperglycemia, and hypertension.

METHODS

Secondary data extracted from a survey of health-care workers conducted from May to July 2014 across 113 hospitals in Taiwan was used. This analysis included 17,152 clinical registered nurses, 1438 nurse practitioners, and 2406 head nurses. Socio-demographic characteristics, job stressors, stress levels, and hyperlipidemia, hyperglycemia, and hypertension variables were extracted.

RESULTS

Perceived stressors differed among clinical registered nurses, nurse practitioners, and head nurses, but overall stress level did not. Nurse practitioners and head nurses showed significantly higher prevalence of hyperlipidemia, hyperglycemia, and hypertension than clinical registered nurses. Higher stress levels, age, body mass index, work hours, and caring for family members were positively associated with hyperlipidemia, hyperglycemia, and hypertension. After adjustment for these variables, risk of hyperlipidemia, hyperglycemia, and hypertension did not differ across the nursing positions.

CONCLUSIONS

Although stressors vary by different nursing positions, overall stress level does not. Hyperlipidemia, hyperglycemia, and hypertension are related to stress level, age, body mass index, weekly working hours, and caring for family members. Hence, alleviating job stress and avoiding long working hours are likely to reduce the risk of hyperlipidemia, hyperglycemia, and hypertension in nurses.

Association between shift work or long working hours with metabolic syndrome: a systematic review and dose-response meta-analysis of observational studies

This meta-analysis investigates the relationship between both shift work and long working hours and risk of developing metabolic syndrome (MetS). PubMed, EMBASE, and Web of Science databases were searched from the outset to December 10, 2019. Two reviewers independently screened studies, extracted data, and assessed the risk of bias of included studies. A total of 36 (30 cross-sectional, 5 cohort, and a nested case-control) studies, involving 274,263 participants, were included. The pooled odds ratio of shift work and development of MetS was 1.35 (95% confidence interval: 1.24-1.48), and the pooled odds ratio of long working hours and development of MetS was 1.19 (95% confidence interval: 0.97-1.46). In the subgroup analysis stratified by gender, the pooled odds ratios for male and female shift workers were 1.25 (95% confidence interval: 1.14-1.37) and 1.47 (95% confidence interval: 1.18-1.82), respectively. The dose-response (number of years of shift work and development of MetS) analysis showed the pooled odds ratio for 5 years of shift work was 1.07 (95% confidence interval: 1.05-1.09) and for 10 years of shift work 1.11 (95% confidence interval: 1.06-1.15). Our meta-analysis confirmed shift work is significantly associated with risk of metabolic syndrome, but the relationship between long working hours and MetS was not substantiated. Additionally, there was a nonlinear dose-response relationship between the number of years of shift work and risk of MetS, showing positive relationship to about 20 years of shift work but not for longer than 20 years. Prospective cohort studies regarding specific shift work schedules are needed to confirm these results.

Overtime Work and the Incidence of Long-term Sickness Absence Due to Mental Disorders: A Prospective Cohort Study

Background

Methods

Results

Conclusion

Are long working hours associated with weight-related outcomes? A meta-analysis of observational studies

The relationship between long working hours and body weight outcomes remains inconclusive; thus, we conducted a meta-analysis to assess the effect of long working hours on weight-related outcomes. PubMed and Embase databases were searched from their inception to June 2019. A random-effects model was used to assess the pooled odds ratio (OR) and corresponding confidence interval (CI). Subgroup analyses and sensitivity analyses were conducted to explore sources of heterogeneity. Publication bias was evaluated by the Begg's and Egger's tests. A total of 29 articles involving 374 863 participants were included. The pooled OR of long working hours on weight-related outcomes was 1.13 (95% CI, 1.07-1.19). In subgroup analysis stratified by definition of outcomes, the pooled ORs of long working hours on "weight gain/BMI increase," "BMI ≥ 25 kg/m² ," and "BMI ≥ 30 kg/m² " were 1.19 (95% CI, 1.02-1.40), 1.07 (95% CI, 1.00-1.14), and 1.23 (95% CI, 1.09-1.39), respectively. We found evidence of publication bias, but correction for this bias using the trim-and-fill method did not alter the combined OR substantially. There was evidence to suggest that long working hours are associated with adverse weight-related outcomes. Preventative interventions such as improved flexibility and healthy working schedules should be established for employees.

Sleep Duration Modifies the Association of Overtime Work With Risk of Developing Type 2 Diabetes: Japan Epidemiology Collaboration on Occupational Health Study

Background

Evidence linking working hours and the risk of type 2 diabetes mellitus (T2DM) is limited and inconsistent in Asian populations. No study has addressed the combined association of long working hours and sleep deprivation on T2DM risk. We investigated the association of baseline overtime work with T2DM risk and assessed whether sleep duration modified the effect among Japanese.

Methods

Participants were Japanese employees (28,489 men and 4,561 women) aged 30–64 years who reported overtime hours and had no history of diabetes at baseline (mostly in 2008). They were followed up until March 2014. New-onset T2DM was identified using subsequent checkup data, including measurement of fasting/random plasma glucose, glycated hemoglobin, and self-report of medical treatment. Hazard ratios (HRs) of T2DM were estimated using Cox regression analysis. The combined association of sleep duration and working hours was examined in a subgroup of workers (n = 27,590).

Results

During a mean follow-up period of 4.5 years, 1,975 adults developed T2DM. Overtime work was not materially associated with T2DM risk. In subgroup analysis, however, long working hours combined with insufficient sleep were associated with a significantly higher risk of T2DM (HR 1.42; 95% CI, 1.11–1.83), whereas long working hours with sufficient sleep were not (HR 0.99; 95% CI, 0.88–1.11) compared with the reference (<45 hours of overtime with sufficient sleep).

Conclusions

Sleep duration modified the association of overtime work with the risk of developing T2DM. Further investigations to elucidate the long-term effect of long working hours on glucose metabolism are warranted.

Short sleep duration, shift work, and actual days taken off work are predictive life-style risk factors for new-onset metabolic syndrome: a seven-year cohort study of 40,000 male workers

BACKGROUND

This longitudinal study investigated the effects of various lifestyle-related factors - including sleep duration, shift work, and actual days taken off work - on new-onset metabolic syndrome (MetS).

METHODS AND RESULTS

A total of 39,182 male employees (mean age 42.4 ± 9.8 years) of a local government organization in Japan were followed up for a maximum of seven years, between 1999 and 2006. Multivariate analysis (Cox proportional hazard method) identified seven high-risk lifestyle factors that were significantly associated with new-onset MetS or a range of metabolic factors (obesity, hypertension, hyperglycemia, dyslipidemia): (1) short sleep duration (<5 h/day), (2) shift work, (3) insufficient number of days off work, (4) always eating until satiety, (5) not trying to take every opportunity to walk, (6) alcohol intake ≥60 g/day, and (7) smoking. In addition, a higher number of these high-risk lifestyle factors significantly promoted the onset of MetS. The hazard ratio for MetS associated with 0-1 high-risk lifestyle parameters per subject at the baseline was set at 1.00. Hazard ratios associated with the following numbers of high-risk lifestyle parameters were: 1.22 (95% CI 1.15-1.29) for 2-3 of these parameters; and 1.43 (1.33-1.54) for 4-7.

CONCLUSION

An increase in the number of high-risk lifestyle factors - such as short sleep duration, shift work, and an insufficient number of days off work - increased the risk of MetS onset. Comprehensive strategies to improve a range of lifestyle factors for workers, such as sleep duration and days off work, could reduce the risk of MetS onset.

[Associations of the work duration, sleep duration and number of holidays with an exaggerated blood pressure response during an exercise stress test among workers]

AIM

It has been reported that an exaggerated systolic blood pressure (ESBP) response during exercise, even if resting blood pressure is normal, is associated with an increased risk of future hypertension and cardiovascular disease (CVD). This study was designed to investigate the relationships of work duration, sleep duration and number of holidays with blood pressure response during an exercise stress test among normotensive workers.

SUBJECTS AND METHODS

The subjects were 362 normotensive workers (79 males and 283 females; age, 49.1 years). A multi-stage graded submaximal exercise stress test was performed on each subject using an electric bicycle ergometer. The workload was increased every 3 minutes, and blood pressure was measured at rest and during the last 1 minute of each stage. In this study, an ESBP response during exercise was defined according to the criteria of the Framingham Study (peak systolic blood pressure ≥210 mmHg in males, or ≥190 mmHg in females). Working environments, work duration, sleep duration, number of holidays, and physical activity during commuting and work, and leisure time exercise duration were evaluated using a questionnaire.

RESULTS

An ESBP response during exercise was observed in 94 (26.0%) workers. The adjusted odds ratio for the prevalence of an ESBP response during exercise was found to be significantly higher with an increase in work duration, decreases in sleep duration and number of holidays (p<0.05, respectively). Moreover, the highest work duration with lowest sleep duration and number of holidays groups had significantly higher adjusted odds ratio for the prevalence of an ESBP response during exercise than the lowest work duration with highest sleep duration and number of holidays groups (p<0.05, respectively).

CONCLUSIONS

Based on our results, we consider that the assessment of blood pressure response during exercise and daily life are necessary to prevent the incidence of future hypertension, CVD and death due to overwork in workers with long-work duration, short sleep duration and small number of holidays.

The association between long working hours and the metabolic syndrome: evidences from the 5th Korean National Health and Nutrition Examination Survey of 2010 and 2012

OBJECTIVES

This study was conducted in order to evaluate the association between the working hours of Korean employees and the metabolic syndrome and the effects of long working hours on metabolic syndrome based on the 5th Korean National Health and Nutrition Examination Survey (2010-2012).

METHODS

Based on the 5th Korean National Health and Nutrition Examination Survey (2010-2012), 4,456 Korean employees without shift work, aged over 15, who work 30 hours or more per week were targeted in this study. The association between the general characteristics, including age, smoking, alcohol drinking, exercise, and the metabolic syndrome criteria defined by International Diabetes Federation (IDF) and weekly working hours were analyzed. In addition, the association between weekly working hours and the metabolic syndrome of the subjects stratified by gender was analyzed through multiple logistic regression analyses and generalized linear mixed model after adjusting the general characteristics.

RESULTS

In the results of stratified analysis by gender, in male subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In female subjects, in comparison with the 30-39 weekly working hours group, there were no significant adjusted odds ratios to the other working hours groups. In addition, no trend associations were observed among weekly working hour groups in both stratified genders.

CONCLUSION

No significant differences in prevalence of metabolic syndrome of the subjects stratified by gender were found according to weekly increasing working hours. However, due to some limitations of this study, further prospective studies may be necessary for verification.

Weekend work and depressive symptoms among Korean employees

The purpose of this study was to quantify the association between weekend work and depressive symptoms in a representative sample of Korean employees. Subjects were 29 171 employees of companies in Korea. Data were obtained as part of the 2011 Korean Working Conditions Survey. Depressive symptoms were measured as a score of ≤7 on the World Health Organization Well-being Index. The association between weekend work and depressive symptoms was quantified using logistic regression, controlling for sociodemographic and work-related factors including the number of hours worked per week and stratified by gender. The prevalence of depressive symptoms was higher in employees who reported working at least one weekend day in the past month than in employees who reported working no weekend days in the past month. After controlling for confounders, including the number of hours worked per week, 1-4 days of weekend work in the past month (odds ratio [95% confidence interval] of 1.36 [1.18-1.57] in males and 1.32 [1.12-1.58] in females) and >4 days of weekend work in the past month (odds ratio [95% confidence interval] of 1.45 [1.19-1.78] in males and 1.36 [1.07-1.73] in females) were significantly associated with depressive symptoms. Weekend work was related with a significant increase in the prevalence of depressive symptoms in Korean workers.

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.

Overtime work and prevalence of diabetes in Japanese employees: Japan epidemiology collaboration on occupational health study

Objective

Epidemiologic evidence on long working hour and diabetes has been conflicting. We examined the association between overtime work and prevalence of diabetes among Japanese workers.

Methods

The subjects were 40,861 employees (35,170 men and 5,691 women), aged 16 to 83 years, of 4 companies in Japan. Hours of overtime were assessed using self-reported questionnaires. Diabetes was defined as a fasting plasma glucose ≥126 mg/dl (7.0 mmol/l), hemoglobin A1c ≥6.5% (48 mmol/mol), or current use of anti-diabetic drug. Multiple logistic regression analysis was used to calculate odds ratio of diabetes for each category of overtime.

Results

After adjustment for age, sex, company, smoking, and BMI, there was a suggestion of U-shaped relationship between overtime work and prevalence of diabetes (P for quadratic trend = 0.07). Compared with those who worked <45 hours of overtime per month, the adjusted odds ratios (95% confidence interval) of diabetes were 0.86 (0.77–0.94), 0.69 (0.53–0.89), and 1.03 (0.72–1.46) for those who worked 45–79, 80–99, and ≥100 hours of overtime per month, respectively. In one company (n = 33,807), where other potential confounders including shift work, job position, type of department, alcohol consumption, sleep duration, leisure time physical activity, and family history of diabetes was additionally adjusted for, similar result was obtained (P for quadratic trend = 0.05).

Conclusions

Long hours of overtime work may not be associated with increased prevalence of diabetes among Japanese workers.