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

Are different perceived stressors associated with metabolic syndrome: a longitudinal cohort study of adults in central Iran

Purpose

The link between metabolic syndrome (MetS) and various stressors has not been thoroughly investigated. We aimed to examine the relationship between MetS and different perceived stressors.

Methods

In this study, we included participants of the Isfahan Cohort study from three counties in central Iran, with data in the 2007 (n = 3178) and 2013 (n = 1693) follow-up stages. We examined the association between distress and perceived stress domains (including job security, job conflicts, personal conflicts, loss and separation, social relations, and health concerns) and MetS.

Results

MetS was identified in 35.8% of participants in the 2007 cohort and 46.2% in the 2013 cohort. In the fully adjusted analysis, the odds ratio (OR) (95%CI) for MetS according to psychological status was 1.65 (1.64-1.65) for psychological distress level, 1.09 (1.01-1.20) for psychological distress score, and 1.21 (1.09-1.42) for total perceived stress score. There was also evidence of association for social relations, personal conflicts, job conflicts, job security, health concern, loss and separation, educational concerns, and sexual life subscales.

Conclusion

Perceived stressors and some of their subscales were associated with MetS.

Characteristics of long working hours and subsequent psychological and physical responses: JNIOSH cohort study

OBJECTIVES

This study aimed to examine the prospective association among objectively measured average working hours (AWHs), frequency of long working hours (FLWHs; defined as ≥205 working hours/month (≥45 hours/week)) for 6 months, and workers' self-reported psychological and physical health.

METHODS

The study included 15 143 workers from 5 Japanese companies. We collected monthly attendance records over 6 months before distributing a questionnaire survey on psychological/physical stress responses and work-related demographics. We then evaluated the associations of those attendance records with psychological/physical measures using analysis of covariance adjusted for sex, age, employment, job type, working conditions, work site and experience of emergency state due to COVID-19.

RESULTS

Irritability, anxiety and depression were significantly greater at ≥180 hours (≥45 hours/week), and fatigue and lack of vigour were greater at ≥205 hours than those of the normal working-hour group (140-180 hours/month [35-45 hours/week]). Psychological indices increased significantly with FLWH, with ≥3 times for irritability, depression and fatigue; ≥2 times for lack of vigour; and ≥1 time for anxiety when compared with no long working hours. No significant associations were observed between AWH or FLWH and physical stress responses.

CONCLUSIONS

Longer AWH was associated with higher levels of psychological stress responses. The effects of FLWH in the past 6 months varied among the psychological stress responses and did not occur for physical complaints. Under circumstances requiring long hours, workers' mental health should be protected through minimising the frequency of long work hours.

Labour-Market Characteristics and Self-Rated Health: Evidence from the China Health and Retirement Longitudinal Study

In the face of labour-force ageing, understanding labour-market characteristics and the health status of middle-aged and older workers is important for sustainable social and economic development. Self-rated health (SRH) is a widely-used instrument to detect health problems and predict mortality. This study investigated labour-market characteristics that may have an impact on the SRH among Chinese middle-aged and older workers, using data from the national baseline wave of the China Health and Retirement Longitudinal Study. The analytical sample included 3864 individuals who at the time held at least one non-agricultural job. Fourteen labour-market characteristics were clearly defined and investigated. Multiple logistic regression models of the associations of each labour-market characteristic with SRH were estimated. Seven labour-market characteristics were associated with higher odds of poor SRH when controlled for age and sex. Employment status and earned income remained significantly associated with poor SRH, when controlling for all the sociodemographic factors and health behaviours. Doing unpaid work in family businesses is associated with 2.07 (95% CI, 1.51-2.84) times probability of poor SRH, compared with employed individuals. Compared with more affluent individuals (highest quintile of earned income), people in the fourth and fifth quintiles had 1.92 (95% CI, 1.29-2.86) times and 2.72 (95% CI, 1.83-4.02) times higher chance, respectively, of poor SRH. In addition, residence type and region were important confounders. Measures improving adverse working conditions should be taken to prevent future risk of impaired health among the Chinese middle-aged and older workforce.

Impact of Reduced Working Hours and Night Work Hours on Metabolic Syndrome: A Quasi-Experimental Study

Objectives

Epidemiological evidence linking long working hours and shift work to metabolic syndrome remains inadequate. We sought to evaluate the impact of reducing working hours on metabolic syndrome.

Methods

We compared the prevalence of metabolic syndrome among male manual workers in a manufacturing company (N = 371) before and after the introduction of policy to reduce daily work hours from 10 to 8 hours. Components of metabolic syndrome were measured in periodic health examinations before the intervention, 6-9 months after, and 1.5-2 years after the intervention. Generalized estimating equation models were used to estimate changes in the prevalence of metabolic syndrome. Analyses were stratified by day work versus shift work.

Results

The results showed a significantly decreased prevalence of metabolic syndrome 6-9 months following the intervention in day workers (risk ratio = 0.68, 95% confidence interval 0.52-0.88), but the benefit disappeared after 1.5-2 years. Shift workers showed a decreased prevalence of metabolic syndrome for the whole follow-up duration after the intervention, although the change was not statistically significant.

Conclusion

Reducing working hours was associated with short-term improvement in metabolic syndrome in male manual workers.

Association between working hours and cancer risk in Japan: The Japan public health center-based prospective study

OBJECTIVES

In this study, we evaluated the association between working hours and cancer risk in the Japanese population, which has not been evaluated.

METHODS

Using a cohort database from a Japan Public Health Center-based Prospective Study, we evaluated 26 738 participants (16 351 men and 10 387 women), who responded to a questionnaire about working hours and followed these participants from 1993-1994 to 2013. Participants were divided into four groups according to working hours (≤6, 7-8, 9-10, ≥11 h/day). The hazard ratio (HR) and 95% confidence interval (CI) of each cancer incidence were calculated using a multivariable-adjusted Cox proportional hazard model.

RESULTS

During 488 383 person-years of follow-up, 481 patients with newly diagnosed cancers were identified. There was no clear association between long working hours and overall cancer, lung cancer, and stomach cancer risks. Long working hours tended to increase prostate cancer risk in men and breast cancer risk in women, although the difference was not statistically significant. Increased liver cancer risk with short working hours (HR [95% CI]; 3.15 [1.44-6.88] in the ≤6 h/day group vs. 7-8 h/day) was observed. Colorectal cancer also tended to increase risk in short working hours, however, there were not statistically significance.

CONCLUSIONS

In this population, long working hours were not associated with cancer risk with statistically significance. The association between short working hours and liver cancer risk was observed, probably due to the reverse causation of liver cancer.

A customized multi-cycle model for measuring the sustainability of circular pathways in agri-food supply chains

Circular economy (CE) is claimed to be a promising pathway to achieve the Sustainable Development Goals (SDGs), but a reliable metric is needed to validate closed-loop strategies by measuring sustainability performances together with the degree of circularity. A significant contribution is offered by Life Cycle (LC) scholars in terms of methodological advances and operational tools for different sectors, also those more complex such as the agro-industrial systems that encompass biological and anthropogenic variables at different scales. However, to date, LC methodologies have not yet answered how to model the complexity of circular pathways. LC evaluations are often modelled for cradle-to-grave analyses, while a circularity evaluation would require an extension of the system boundaries to more interconnected life cycles, orienting towards a cradle-to-cradle perspective. This research gap led us to propose a multi-cycle approach with expanded assessment boundaries, including co-products, into a cradle-to-cradle perspective, in an attempt to internalize circularity impacts. The customized LC framework here proposed is based on the Life Cycle Assessment (LCA), the Environmental Life Cycle Costing (ELCC) in terms of internal and external costs, and the Social Life Cycle Assessment (SLCA) in terms of Psychosocial Risk Factor (PRF) impact pathway. The model is designed to be applied to the olive-oil sector, which commonly causes significant impacts by generating many by-products whose management is often problematic. Results are expected to show that the customized LC framework proposed can better highlight the environmental and socioeconomic performances of the system of cycles, allowing CE to deliver its promises of sustainability, as the circularity of materials per se is a means, not an end in itself.

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.

Age, Sex, and Profession Difference Among Health Care Workers With Burnout and Metabolic Syndrome in Taiwan Tertiary Hospital-A Cross-Section Study

Background

This cross-sectional study aimed to analyze the association between burnout, work-related factors and metabolic syndrome (MetS) among various health-care workers (HCWs) at a tertiary hospital in Taiwan.

Methods

Relevant demographic data were obtained through written questionnaires. Information about psychosocial and work conditions, including assigned department, working hours, shifts, and sleep condition, was obtained. Burnout was evaluated according to the Chinese version of Maslach Burnout Inventory-Health Services Survey. MetS was analyzed according to the criteria of the National Cholesterol Education Program of Taiwan-Treatment Panel for Adults III.

Results

A total of 1,055 non-doctor/nurse and 2,078 doctor/nurse staff with a median age of 45.2 and 36.1 years participated in this study. The incidence of burnout was nearly 6.42 and 6.68% and that of MetS was 31.4 and 13.5% in non-doctor/nurse and doctor/nurse staff, respectively. The results showed that burnout induced a higher Odds ratio (OR) of MetS in the doctor/nurse group (OR = 1.96, p = 0.01). Other factors, such as night shift and seniority (>10 years), led to a higher OR of MetS, but a decreased risk was observed based on seniority (2-4 years). Further, young female participants and young doctors/nurses with burnout had a higher OR of MetS compare to other groups (OR = 2.43 and 2.32, p < 0.05).

Conclusion

The study results suggested positive relationship between burnout and MetS in young female staffs and young doctors/nurses. For doctor/nurse staff with higher seniority or more night shifts, strategies are needed to prevent burnout and MetS.

Poor worker’s long working hours paradox: evidence from the Korea National Health and Nutrition Examination Survey, 2013-2018

Background

Because income and working hours are closely related, the health impact of working hours can vary according to economic status. This study aimed to investigate the relationship between working hours and the risk of poor self-rated health according to household income level.

Methods

We used the data from the Korea National Health and Nutrition Examination Survey VI and VII. The information on working hours and self-rated health was obtained from the questionnaire. After stratifying by household income level, the risk of poor self-rated health for long working hour group (≥ 52 hours a week), compared to the 35–51 working hour group as a reference, were calculated using multiple logistic regression.

Results

Long working hours increased the risk of poor self-rated health in the group with the highest income, but not in the group with the lowest income. On the other hand, the overall weighted prevalence of poor self-rated health was higher in the low-income group.

Conclusions

The relationship between long working hours and the risk of poor self-rated health varied by household income level. This phenomenon, in which the health effects of long working hours appear to diminish in low-income households can be referred to as the ‘poor worker’s long working hours paradox’. Our findings suggest that the recent working hour restriction policy implemented by the Korean government should be promoted, together with a basic wage preservation to improve workers’ general health and well-being.

Health problems associated with single, multiple, and the frequency of months of objectively measured long working hours: a cohort study by the National Institute of Occupational Safety and Health, Japan

Purpose

We aimed to examine the prospective associations of monthly working hours measured in a month, the 6-month averaged hours, and the frequency of long working hours (≥ 205 h/month) during the past 6 months with health indicators.

Methods

This study included 6,806 Japanese company workers (response rate = 86.6%). Data on the workers’ monthly attendance during the second half of fiscal year 2016 and annual health checkups in fiscal years 2016 and 2017 were collected. We evaluated the association of the above three types of monthly working hours with subsequent health checkup data in fiscal year 2017. We adjusted for the corresponding data in fiscal year 2016.

Results

Multivariate logistic regression analyses revealed significant associations between monthly working hours and workers’ systolic and diastolic blood pressure as well as aspartate aminotransferase, alanine aminotransferase, low-density lipoprotein cholesterol (LDL), and triglyceride levels. However, the associations were not consistent between months. The average monthly working hours were significantly associated with higher LDL levels for the 220–240 h/mo group (OR: 1.49, 95%CI: 1.07–2.08) and lower triglyceride levels for the < 140 h/mo group (OR: 0.15, 95%CI: 0.03–0.77), compared to the 140–180 h/mo group. The frequency of long working hours was significantly associated with higher LDL levels.

Conclusions

Working hours over several months produced various associations with health indicators compared to those measured in a single month. Our present data suggest that the effects of average or frequency of long working hours during the past 6 months are likely to appear in LDL levels.

Impact of Long Working Hours and Shift Work on Unmet Health Care Need Among Korean Workers

Background

This study aimed to identify work-related risk factors, including long working hours and night/shift work, for unmet health care need using data of a representative panel of Korean adults.

Methods

Associations between work-related factors and unmet health care need were analyzed using data of 3,440 participants (10,320 observations) from the 2011-2013 Korean Health Panel Study. A generalized estimating equation was used for the analysis of repeated measures.

Results

The prevalence of unmet health care was 16.6%. After adjusting sex, age, socioeconomic status, work characteristics, and working more than 60 hours per week (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.23–1.65) or 50–59 hours per week (OR: 1.26, 95% CI: 1.08–1.46) instead of 40–49 hours per week and night/shift work (OR: 1.27, 95% CI: 1.06–1.51) were associated with unmet health care need.

Conclusion

Long working hours and night/shift work are risk factors for unmet health care need among the Korean working population.

Does an increase in working hours affect mortality risk? The relationship between working hours and mortality among the older population

BACKGROUND

Population aging, caused by an increase in life expectancy and decrease in fertility rates, has created changes and challenges in various spheres, including the labor market. Though health deteriorates with age, more and more older adults choose to stay in the labor force and work into late life.

OBJECTIVE

Understanding the effects of various work conditions on the health of older workers is crucial for designing policies and interventions to ensure healthy late life and maintain a productive workforce. To contribute to this endeavor, this study investigates the relationship between long working hours (LWH) and mortality among older populations.

METHODS

The study uses the Cox proportional hazards regression model to investigate data from the Health and Retirement Survey (HRS) between the years 1992-2016, a longitudinal nationally representative dataset from the United States.

RESULTS

The results indicate that working 50 hours or more per week is not associated with an increased risk of mortality, for the full sample (1.45 [95% CI: 0.86, 2.45]), for both genders (females 0.51 [95% CI: 0.06, 4.28], males 1.45 [95% CI: 0.81, 2.61]), and for immigrants (female immigrants 0.55 [95% CI: 0.06, 4.75], male immigrants 1.44 [95% CI: 0.79, 2.62]).

CONCLUSIONS

This analysis confirms and extends the findings of earlier studies by taking into consideration the potential impact of many demographic, socioeconomic, work-related and health-related factors.

Long working hours are associated with a higher risk of non-alcoholic fatty liver disease: A large population-based Korean cohort study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), a common chronic liver disease, may progress to fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure. But only a few cross-sectional studies have reported an association of NAFLD with working hours. This cohort study further examined the association between working hours and the development of NAFLD.

METHODS

We included 79,048 Korean adults without NAFLD at baseline who underwent a comprehensive health examination and categorized weekly working hours into 35-40, 41-52, 53-60, and >60 hours. NAFLD was defined as the presence of fatty liver, in the absence of excessive alcohol use, as observed by ultrasound.

RESULTS

During a median follow-up of 6.6 years, 15,095 participants developed new-onset NAFLD (incidence rate, 5.55 per 100 person-years). After adjustment for confounders, the hazard ratios (95% confidence interval) for the development of NAFLD in 41-52, 53-60, and >60 working hours compared with that in 35-40 working hours were 1.07 (1.02-1.13), 1.06 (1.00-1.13), and 1.13 (1.05-1.23), respectively. Furthermore, the association remained significant after confounders were treated as time-varying covariates.

CONCLUSION

In this large-scale cohort, long working hours, especially >60 working hours a week, were independently associated with incident NAFLD. Our findings indicate that long working hours are a risk factor for NAFLD.

Current Options and Future Directions for NAFLD and NASH Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with a broad spectrum ranging from simple steatosis to advanced stage of nonalcoholic steatohepatitis (NASH). Although there are many undergoing clinical trials for NAFLD treatment, there is no currently approved treatment. NAFLD accounts as a major causing factor for the development of hepatocellular carcinoma (HCC), and its incidence rises accompanying the prevalence of obesity and diabetes. Reprogramming of antidiabetic and anti-obesity medicine is a major treatment option for NAFLD and NASH. Liver inflammation and cellular death, with or without fibrosis account for the progression of NAFLD to NASH. Therefore, molecules and signaling pathways involved in hepatic inflammation, fibrosis, and cell death are critically important targets for the therapy of NAFLD and NASH. In addition, the avoidance of aberrant infiltration of inflammatory cytokines by treating with CCR antagonists also provides a therapeutic option. Currently, there is an increasing number of pre-clinical and clinical trials undergoing to evaluate the effects of antidiabetic and anti-obesity drugs, antibiotics, pan-caspase inhibitors, CCR2/5 antagonists, and others on NAFLD, NASH, and liver fibrosis. Non-invasive serum diagnostic markers are developed for fulfilling the need of diagnostic testing in a large amount of NAFLD cases. Overall, a better understanding of the underlying mechanism of the pathogenesis of NAFLD is helpful to choose an optimized treatment.

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.

Long Working Hours and Risk of Nonalcoholic Fatty Liver Disease: Korea National Health and Nutrition Examination Survey VII

BACKGROUND

The global incidence of NAFLD is rising sharply due to various risk factors. As previous studies reported adverse health impact of long working hours on metabolic diseases, such as diabetes mellitus and obesity, it is plausible that NAFLD is also associated with working excessive hours. However, data regarding this issue is limited.

METHODS

In this cross-sectional study based on Korea National Health and Nutrition Examination Survey VII, 5,661 working adults without previous liver disease or heavy alcohol drinking habits were included. The subjects were categorized into three groups according to working hours: 36-42, 43-52, and 53-83 hours/week. NAFLD was defined using the hepatic steatosis index (HSI), which is a validated prediction model for determining NAFLD.

RESULTS

The prevalence of NAFLD (HSI ≥36) increased with longer working hours: 23.0%, 25.6%, and 30.6% in the 36-42, 43-52, and 53-83 hours/week group, respectively (p <0.001). Subjects who worked 53-83 hours/week had higher odds for NAFLD than those who worked the standard 36-42 hours/week (OR 1.23, 95% CI 1.02-1.50, p = 0.033) after adjusting for age, sex, body mass index, smoking, alcohol, exercise, diabetes mellitus, hypertension, serum triglyceride, and total cholesterol. This association was consistent across subgroups according to working schedule (daytime vs. shift workers) or occupation type (office vs. manual workers). In particular, the relationship between long working hours and NAFLD was pronounced in workers aged <60 years and in female workers.

CONCLUSIONS

Long working hours was significantly associated with NAFLD. Further prospective studies are required to validate this finding with causal relationship.

Burnout and metabolic syndrome among different departments of medical center nurses in Taiwan-Cross-sectional study and biomarker research

OBJECTIVES

The cross-sectional study aimed to analyze the association between burnout, work-related factors, and metabolic syndrome (Mets) in nurses from several departments of a tertiary hospital in Taiwan. Exploring biomarkers could provide for prevention.

METHODS

Demographic data were obtained through a written questionnaire and include the following information: gender, age, education level, psychosocial and work situations, such as departments, working hours, work shift, depression, and sleep time. Burnout was evaluated according to the Chinese Burnout inventory, Mets was evaluated according to the criteria of the National Cholesterol Education Program of Taiwan-Treatment Panel for Adults III (NCEP-ATP III).

RESULTS

A total of 1758 nurses participated with a median age of 35.2 years. The prevalence of burnout and Mets was 6.4% and 13.84%, respectively. The results showed that burnout induced higher risk of Mets, odds ratio (OR) 1.70 (95% confidence interval, 1.04-3.05). Other factors, such as out-patient nurses, seniority (4-10 and >10 years), working hours (51-59 h/wk), nigh shift, Brief Symptom Rating Scale-5 (score 10-14 and ≧15), poor self-rated health status, and inadequate sleep time, led to higher risk of Mets. Biomarkers research showed that Glycated hemoglobin (Hba1c) was significantly associated with burnout nurses (OR = 24.72, P < .001), but thyroid-stimulating hormone and free thyroxin were not.

CONCLUSIONS

Results suggested positive associations between burnout and Mets in nurses. For nurses with higher seniority, long hours of work, night shifts, poor physical and mental conditions, and poor lifestyle habits in different departments, strategies are needed to prevent burnout and Mets.

Burnout and metabolic syndrome among healthcare workers: Is subclinical hypothyroidism a mediator?

OBJECTIVES

Evidence suggests that subclinical hypothyroidism (SCH) is associated with burnout and metabolic syndrome (MetS). We examined the relationship between burnout and MetS among healthcare workers (HCWs) and investigated the potential mediation of SCH.

METHODS

This cross-sectional study included HCWs from a tertiary medical center; demographic data were obtained using a questionnaire. Burnout was evaluated according to the Chinese version of the Maslach Burnout Inventory-Health Services Survey (MBI-HSS). MetS and thyroid function data were obtained from a physical check-up. Logistic regression models were used to evaluate the adjusted odds ratio (aOR), and mediation analysis was employed to examine the mediation effect.

RESULTS

Among 945 non-doctor/nurse and 1868 doctor/nurse staff, MetS was 30% and 14%, respectively, and the prevalence of burnout was nearly 6.5%. The results showed that burnout induced higher aOR of MetS in the doctor/nurse group (1.27, 95% confidence interval [CI]: 1.05-3.62). Thyroid-stimulating hormone (TSH) showed a positive association factor of MetS in doctor/nurse group-adjusted burnout (aOR = 1.15, 95% CI: 1.01-4.19). A higher TSH level was associated with an increased odds of MetS in younger doctor/nurse staff with burnout syndrome (aOR = 1.74; 95% CI: 1.04-3.22). There was a borderline significant mediation effect of SCH in the association between burnout and MetS in doctor/nurse staff.

CONCLUSIONS

The results showed that higher TSH levels were positively associated with burnout and MetS in doctor/nurse professionals, especially in the young cohort. Burnout may rely on the borderline mediation effect of SCH, which is likely to affect MetS.

Association between metabolic syndrome and work: an integrative review of the literature

The aim of this study was to highlight the association between occupational aspects and the occurrence of metabolic syndrome among various occupational groups. This is an integrative review of the literature that included articles indexed in the following databases: LILACS, SciELO, PubMed, and CINAHL. We evaluated 32 articles, most of which were published in Englishlanguage medical journals and with level 4 scientific evidence. The occupational aspects most commonly reported as associated with metabolic syndrome were occupation, work shift, and occupational stress. Our results indicated that occupational aspects could negatively interfere with workers’ health; more robust longitudinal studies should contribute to further uncovering the reported associations.

Long Work Hours Are Associated with Hypothyroidism: A Cross-Sectional Study with Population-Representative Data

Background: Studies have highlighted the adverse effects of long work hours on workers' health; however, the association of long work hours with thyroid function has not been studied. This study aimed at assessing long work hours as a risk factor for thyroid dysfunction. Methods: This cross-sectional study was based on data obtained from the Korea National Health and Nutrition Examination Survey conducted from 2013 to 2015. A total of 2160 adults who worked 36-83 hours per week were included. Thyroid function was defined based on the population thyroid-stimulating hormone reference ranges, after excluding individuals with positive results for thyroid peroxidase antibody. The association between work hours and thyroid function was confirmed via multinomial logistic regression. Results: Hypothyroidism was more prevalent among those with longer work hours (3.5% vs. 1.4% for 53-83 and 36-42 work hours per week, respectively). Individuals who worked longer hours had an increased odds for hypothyroidism (odds ratio 1.46, confidence interval 1.12 - 1.90, per 10-hour increase in work hours per week), after adjustment for age, sex, body mass index, urine iodine concentration, smoking status, work schedule, and socioeconomic status. The association between work hours and hypothyroidism was consistent in various subgroups stratified by sex or socioeconomic status. Conclusions: To our knowledge, this study is the first to show that long work hours are associated with hypothyroidism. Further large longitudinal studies are needed to clarify causality.

The negative impact of long working hours on mental health in young Korean workers

Long working hours are known to have a negative effect on health. However, there is no clear evidence for a direct link between mental health and long working hours in the young adult populations. Therefore, we aimed to determine whether long working hours are associated with mental health in young adult workers. Data were collected from a 2012 follow-up survey of the Youth Panel 2007. A total of 3,332 young adult employees (aged 20 to 35) were enrolled in the study. We analyzed stress, depression, and suicidal thoughts by multivariate logistic regression analysis based on working hours (41 to 50, 51 to 60 and over 60 hours, compared to 31 to 40 hours per week), which was adjusted for sex, age, marriage status, region, and educational level. From the 3,332 young adult employees, about 60% of the workers worked more than 40 hours and 17% of the workers worked more than 50 hours per week. In a Chi-square test, stress level, depression, and suicidal thoughts increased with increasing working hours (p-value <0.001, 0.007, and 0.018, respectively). The multivariate logistic regression model showed that, compared to the 31 to 40 hours per week group, the adjusted odds ratios of the 41 to 50, 51 to 60, and over 60 hours per week groups for stress were 1.46(1.23–1.74), 2.25(1.79–2.83) and 2.55(1.72–3.77), respectively. A similar trend was shown in depression [odds ratios: 2.08(1.23–3.53), 2.79(1.44–5.39) and 4.09(1.59–10.55), respectively] and suicidal ideation [odds ratios: 1.98(0.95–4.10), 3.48(1.48–8.19) and 5.30(1.61–17.42), respectively]. We concluded that long working hours were associated with stress, depression, and suicidal ideation in young employees, aged 20 to 35.

Association between Working Hours and Self-Rated Health

This study compared the association between working hours and self-rated health (SRH) according to sex, socioeconomic status, and working conditions. In all, 25,144 participants were selected from the Korea National Health and Nutrition Examination Survey (KNHANES), conducted from 2010 to 2018. The risks of poor SRH, according to working hours, were investigated using multiple logistic regression. Both short and long working hours were associated with poor SRH. Men working short hours and women working long hours were at risk of poor SRH. Workers with fewer than nine years of education were at risk of poor SRH when working short hours, whereas workers with more than nine years of education were at risk when working long hours. Similarly, simple laborers were at risk of poor SRH when working short hours, while managers and professional workers were at risk when working long hours. When working for short hours, paid employees were at risk of poor SRH. Workers with a non-fixed work schedule showed no risk of poor SRH when working long or short hours. In conclusion, workers working short hours with low education and workers working long hours with high education were at risk of poor SRH. Working conditions were significantly related to the association between SRH and working hours.

Sleep problems of healthcare workers in tertiary hospital and influencing factors identified through a multilevel analysis: a cross-sectional study in China

OBJECTIVES

Sleep problems are common among healthcare workers, especially among those who work in tertiary hospitals; however, studies focusing on healthcare workers in tertiary hospitals in China are limited. Therefore, we aimed to examine the prevalence of sleep problems among tertiary hospital employees in China and identify associated factors.

DESIGN

Cross-sectional questionnaire survey study.

SETTING

The study was conducted in 317 departments at 33 tertiary hospitals in the Heilongjiang Province, China.

PARTICIPANTS

The study included a representative sample of 4007 healthcare workers, including clinicians, medical technicians and office workers, who were selected using a multistage cluster sampling method. Ultimately, 3810 participants completed valid questionnaires, yielding a response rate of 95%.

PRIMARY AND SECONDARY OUTCOME MEASURES

Participants completed a structured questionnaire which collected data regarding demographics, sleep problems, employment, chronic pain and health-related behaviours. A two-level logistic regression model was constructed to examine determinants of sleep problems.

RESULTS

We found that nearly half of the respondents reported experiencing sleep problems. The two-level logistic model suggested a positive association of sleep problems with headache (OR=2.64, 95% CI=2.27 to 3.07), working hours (OR=1.41, 95% CI=1.20 to 1.66) and night shifts (OR=1.43, 95% CI=1.21 to 1.69). In contrast, regular diet (OR=0.44, 95% CI=0.36 to 0.53) and exercise (OR=0.65, 95% CI=0.53 to 0.80) protected the study population against sleep problems.

CONCLUSIONS

We found that sleep problems are prominent among tertiary hospital employees in China. The risk factor most strongly associated with sleep problems was headaches. To alleviate sleep problems in this population, medical institutions and health policy makers should establish reasonable working schedules and night-shift work systems, while the healthcare workers themselves should pay attention to their chronic pain problems and engage in regular diet and exercise.

The Association Between Long Working Hours and High-Sensitivity C-Reactive Protein in Older Aged Individuals: The Korea National Health and Nutrition Examination Survey (KNHANES) 2015

OBJECTIVE

The objective of this study was to show the association of high-sensitivity C-reactive protein (hs-CRP) level with working hours in different age groups.

METHODS

We used data from Korean National Health and Nutrition Survey. The odds ratios (ORs) and 95% confidence intervals (CIs) of variables for elevated hs-CRP (>3.0 mg/L) were generated with logistic regression models. Significant variables were verified with an adjusted multivariate logistic model after stratification of age groups.

RESULTS

Working for more than 55 hours per week was associated with elevated hs-CRP level in the old-ages group (≥ 60 years old: OR 2.18, 95% CI 1.07 to 4.45). Working for 40 to 55 hours per week was associated with decreased hs-CRP in the young-ages group (OR 0.58, 95% CI 0.37 to 0.93).

CONCLUSION

Working hours appear to influence the levels of hs-CRP in individuals aged older than 60 years.

Working hours and nonalcoholic fatty liver disease according to sleep duration

There is no study on the relationship between working hours and nonalcoholic fatty liver disease (NAFLD). The objective of the present study was to determine the relationship between working hours and NAFLD by sleep duration using a large set of abdominal ultrasonography examination data. Data from 194,625 patients who underwent health examinations from 2015 to 2017 were analyzed. Chi-square tests, linear-by-linear association and ANOVA were performed to compare general characteristics according to working hours. Multivariate logistic regression analysis was performed to determine the relationship between working hours and NAFLD by sleep duration. There was no significant relationship between working hours and NAFLD prevalence in the group of short sleep duration of ≤5 hours or the group of long sleep duration of ≥7 hours. The risk of NAFLD in the >52 working hour group was significantly higher (aOR, 1.09; 95% CI, 1.04-1.14) than that in the 40- to 52-hour working hour group after adjusting for confounding factors in the 5- to 6-hour sleep duration group. There was no significant difference between ≤40 working hours and 40 ~ 52 working hours in the 5 ~ 6 hours sleep duration group (aOR, 1.02; 95% CI, 0.97-1.06). In general, working hours were significantly related to NAFLD. There was a difference in the relationship between working hours and NAFLD according to sleep duration.

The association between long working hours and marital status change: middle-aged and educated Korean in 2014-2015

Background

We investigated the association between long workhours and marital status change from married to divorced or separated status that might have bad health effects.

Methods

A total of 40,654 participants with married status in 2014 were followed up in 2015. Weekly workhours were categorized into four groups: ≤ 40, 41–52, 53–60, and > 60 hours per week. Univariate and multivariate logistic regression analyses were performed to determine the relationship between groups of workhours and marital status change after adjusting for age, total monthly household income, working type, and depression with sex stratification.

Results

The study populations consisted of 8,346 (20.5%) females and 32,308 (79.5%) males. Odd ratios (ORs) of marital status change for females working for more than 60 hours per week was 4.26 (95% confidence interval [CI]: 1.25–14.5), when working less than or equal to 40 hours per week was used as reference in the crude model. ORs of working more than 60 hours per week was 4.57 (95% CI: 1.02–20.5) in female workers when considering age, total household earning per month, working type of daytime, and depression in a dose-response manner. However, for male workers, long workhours were not significantly related to change of marriage status.

Conclusions

Long workhours for more than 60 hours per week had significantly higher risk of divorce or separation in females, but not in males. Further follow-up studies are needed to evaluate long term effects of long workhours on divorce risk.

Differential effects of employment grade on the association between long working hours and problem drinking

OBJECTIVE

To examine the association between working hours and problem drinking in employees from different employment grades.

METHODS

We used data from a national survey of randomly sampled Taiwanese workers. A total score of 2 or more on the Cut down, Annoyed, Guilty, and Eye-Opener (CAGE) questionnaire was used to identify problem drinkers. Weekly working hours were categorized into five groups: <40, 40, 41-48, 49-59, and ≥60. Employees were classified into three employment grades: managers and professionals, skilled workers, and low-skilled workers. The associations between working hours and problem drinking in employees from different employment grades were examined by logistic regression models.

RESULTS

In skilled workers, problem drinking was associated with <40 and 41-48 working hours, but not with >48 working hours. In low-skilled workers, problem drinking was most strongly associated with 49-59 working hours.

CONCLUSION

The association between working hours and problem drinking was not linear and differed with employment grades.

Lean non-alcoholic fatty liver disease patients had comparable total caloric, carbohydrate, protein, fat, iron, sleep duration and overtime work as obese non-alcoholic fatty liver disease patients

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial disease that involves a complex interaction between genetics, diet, and lifestyle. Although closely related with obese subjects, it is also common in lean humans. This study aimed to characterize the diet and lifestyle of lean and obese NAFLD patients in China.

METHODS

To characterize the diet and lifestyle of lean and obese NAFLD patients, we conducted a matched case-control study that included 351 Chinese adults. General characteristics, dietary intake, and lifestyle were gathered by using a valid and reliable dietary questionnaire. We compared the dietary intake and lifestyle between lean and obese NAFLD patients.

RESULTS

All NAFLD patients had more total caloric, calorigenic nutrients (carbohydrate, fat, and protein), grain, potato, fruit, and iron with higher levels of waist circumference and overtime work but shorter sleep duration than their corresponding controls. Particularly, lean NAFLD patients consumed comparable total caloric, calorigenic nutrients, iron, sleep duration, and overtime work as obese NAFLD patients, though they consumed lower levels of grain, potato, and fruit (lean NAFLD patients vs. obese NAFLD patients: mean ± SD, g/day grain: 291.8 ± 83.8, 365.2 ± 89.0; potato: 63.5 ± 33.1, 80.4 ± 37.6; fruit: 324.3 ± 148.4, 414.0 ± 220.4; P < 0.0001).

CONCLUSION

Non-alcoholic fatty liver disease patients had higher total caloric, calorigenic nutrients, grain, potato, fruit, iron, and overtime work but shorter sleep duration. Lean NAFLD patients had comparable total caloric, calorigenic nutrients, iron, sleep duration, and overtime work as obese NAFLD patients. These features could be used to the nutritional education and therapeutic guidance for lean NAFLD patients in the future.

The Relationship between Workplace Environment and Metabolic Syndrome

Background:

Metabolic syndrome, a major risk factor for cardiovascular disease and diabetes, is recognized as an important health problem.

Objective:

To investigated whether the workplace environment was associated with metabolic syndrome.

Methods:

This study was a cross-sectional study using medical records and workplace environment reports of 1297 blue-collar Korean male workers who exposed to work hazards in one workplace. The metabolic syndrome was confirmed using the NCEP ATP III. The workplace environment was classified into organic compounds, metals, acids and bases, metalworking fluid, dust, noise and shift worker.

Results:

Among the total subjects, 257 (19.8%) had metabolic syndrome. Age, BMI, current smoking status, and at risk alcohol drinking were found to be significant predictors of metabolic syndrome. In seven workplace environment categories, the odds ratio (OR) of metabolic syndrome increased 1.785 (95% CI 1.058 to 3.013) times in the metalworking fluid environment.

Conclusion:

The workplace environment, especially metalworking fluid is associated with metabolic syndrome.

Long working hours, anthropometry, lung function, blood pressure and blood-based biomarkers: cross-sectional findings from the CONSTANCES study

Background

Although long working hours have been shown to be associated with the onset of cardiometabolic diseases, the clinical risk factor profile associated with long working hours remains unclear. We compared the clinical risk profile between people who worked long hours and those who reported being never exposed to long hours.

Methods

A cross-sectional study in 22 health screening centres in France was based on a random population-based sample of 75 709 participants aged 18–69 at study inception in 2012–2016 (the CONSTANCES study). The data included survey responses on working hours (never, former or current exposure to long working hours), covariates and standardised biomedical examinations including anthropometry, lung function, blood pressure and standard blood-based biomarkers.

Results

Among men, long working hours were associated with higher anthropometric markers (Body Mass Index, waist circumference and waist:hip ratio), adverse lipid levels, higher glucose, creatinine, white blood cells and higher alanine transaminase (adjusted mean differences in the standardised scale between the exposed and unexposed 0.02–0.12). The largest differences were found for Body Mass Index and waist circumference. A dose–response pattern with increasing years of working long hours was found for anthropometric markers, total cholesterol, glucose and gamma-glutamyltransferase. Among women, long working hours were associated with Body Mass Index and white blood cells.

Conclusion

In this study, men who worked long hours had slightly worse cardiometabolic and inflammatory profile than those who did not work long hours, especially with regard to anthropometric markers. In women, the corresponding associations were weak or absent.

Long Working Hours and Risk of Cardiovascular Disease

Purpose of Review

To summarize the evidence on the relationship between long working hours and cardiovascular disease, such as coronary heart disease and stroke.

Recent Findings

Large-scale meta-analyses with published and individual participant observational data on more than 740,000 men and women free of cardiovascular disease report a link between long working hours (≥ 55 h a week) and the onset of cardiovascular events. Our meta-analytic update of summary evidence suggests a 1.12-fold (95% CI 1.03–1.21) increased risk associated with coronary heart disease and a 1.21-fold (95% CI 1.01–1.45) increased risk of stroke, although the evidence is somewhat inconsistent and the possibility of residual confounding and bias cannot be ruled out. Few studies have examined the mechanisms which may be stress-related, behavioral, or biological. The recent pooled analyses suggest that increased cardiac electric instability and hypercoagulability might play a role.

Summary

The evidence that long working hours are a risk factor for cardiovascular disease is accumulating and suggests a small risk. Studies on the effects of long working hours in high-risk populations and those with pre-existing cardiovascular disease, mechanistic research, and intervention studies are needed to advance this research field.

Alcohol consumption frequency or alcohol intake per drinking session: Which has a larger impact on the metabolic syndrome and its components?

OBJECTIVES

This study investigated the relationship between drinking behavior (alcohol consumption frequency, average alcohol intake per drinking session) and the prevalence of metabolic syndrome (MetS) and its components (central obesity, raised triglycerides, decreased HDL cholesterol, raised blood pressure, raised fasting plasma glucose) in Korean men and women above the age of 20.

METHODS

Our study employed data from the Korea National Health and Nutritional Examination Survey (KNHANES) for the years 2007-2013. The study population consisted of a total of 16,507 Korean males and 22,548 females; 30.0% (n = 4908) of all males and 29.8% (n = 6663) of all females were diagnosed with metabolic syndrome.

RESULTS

Relative to abstaining males, males who consumed alcohol more than 2-3 times per week (OR: 1.32, 95% CI: 1.04-1.66), as well as those who consumed more than 10 drinks per drinking session (OR: 1.71, 95% CI 1.41-2.08) had greatly increased odds risk of MetS. Alcohol consumption frequency was not associated with increased odds risk of MetS for females, however. Relative to abstaining females, females who consumed just 3-4 drinks per session had a 17% increased odds risk of MetS (OR: 1.17, 95% CI: 1.02-1.35). Females consuming more than 10 drinks per drinking session (OR: 1.91, 95% CI 1.44-2.52) were likely to have a 91% increase in odds risk of MetS. For males, alcohol consumption frequency was associated with high blood pressure and high fasting plasma glucose levels, while average alcohol intake per drinking session was associated with central obesity, high triglyceride levels, high blood pressure, and high fasting plasma glucose. For females, alcohol intake per session was associated with central obesity, high triglycerides, raised blood pressure, and high fasting plasma glucose.

CONCLUSIONS

Frequent alcohol consumption and high alcohol intake per drinking session were associated with higher prevalence of MetS and its components for Korean men; alcohol intake per drinking session only was associated with higher prevalence of MetS and its components for Korean women.

Prevalence of metabolic syndrome among employees of a taiwanese hospital varies according to profession

This study aimed to explore the prevalence of metabolic syndrome (MS) among various employee groups at a Taiwan hospital.We retrospectively compared the prevalence of MS, as defined by the Taiwan Department of Health, among employee groups (physicians, nurses, medical technicians, and administrative staff) at a medical center in northern Taiwan in 2011. Total cholesterol was used in lieu of high-density lipoprotein cholesterol values.The overall prevalence of MS among the 1673 men and 5117 women investigated was 12.0%. Physicians had the highest prevalence of MS (18.3%). Abdominal obesity and high blood sugar were the most (29.3%) and least (10.5%) prevalent abnormalities, respectively.The hospital employees had a moderate prevalence of MS. Physicians and administrative staff members had higher prevalence of MS than the other populations.

Long Working Hours and the Risk of Chronic Disease

A change in employment trends, in the nature of occupation and in the number of working hours has an impact on the diseases prevalent in people. Using data from a World Health Organization 2007 study on global ageing and adult health, this research looks at the effect of past work histories on the prevalence of selected chronic diseases such as hypertension, diabetes, stroke, angina and depression in India. By using a bivariate and multivariate analysis, this study shows that all the selected chronic diseases were significantly higher in urban areas, especially amongst people who were educated upto a higher secondary level and above and were from the richest wealth quintile. The chances of all these selected chronic diseases, except for depression, were also found to be significantly higher among those who were working in the non-manual sector. It was also found that the expected odds of having diabetes and stroke were significantly higher among those employees who worked for more than eight hours a day than their counterparts who worked for less than eight hours a day after adjusting important confounders. Based on these findings, the study suggests that the government should implement some specific policy measures; and take steps which will help employees cope with harmful work schedules.

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.

Relationship Between Long Working Hours and Metabolic Syndrome Among Korean Workers

PURPOSE

This study investigated gender differences in the relationship between long working hours and metabolic syndrome.

METHODS

Data based on the Sixth National Health and Nutrition Examination Survey (2014) pertaining to a total of 1,145 paid workers were analyzed. Working hours were divided into three groups (40-51 hours/week, 52-59 hours/week, ≥ 60 hours/week). The relationship between working hours and metabolic syndrome was then analyzed after adjusting for general and occupational characteristics, using a multiple logistic regression model.

RESULTS

Working 40-51 hours per week was associated with the lowest metabolic syndrome among female workers (11.2%), whereas it was associated with the highest metabolic syndrome among male workers (28.0%). After adjusting for general and occupational characteristics, female workers working≥60 hours per week showed odds ratios of 2.21 [95% confidence interval (1.07, 4.57)], compared to those who worked 40-51 hours per week. However, no clear association between long working hours and metabolic syndrome was found among male workers.

CONCLUSION

The results suggest that working long hours, especially≥60 hours per week, is related to metabolic syndrome among female Korean workers.

Prevalence of metabolic syndrome among Iranian occupational drivers

AIMS

Compared with other members of a society, drivers are under more periodic and constant surveillance due mainly to this fact that their type of work requires them to spend most of their times in a sedentarily position. The recent survey had done to evaluate the prevalence of Met Syn among professional drivers in northeast area of Iran.

MATERIALS AND METHODS

To evaluate the prevalence of Met Syn among long-haul drivers, 1018 male drivers were studied. Definition of Met Syn was based on ATP III, IDF and AHA. The statistical tests were composed of chi-square and independent t tests.

RESULTS AND CONCLUSION

The participants' mean age was 42.17±10.65 years. The prevalence of Met Syn according to ATP III, IDF and AHA criteria was 26.1%, 35.2% and 31.6% respectively. 6.6% of drivers were impaired fasting glucose. The drivers with the bus, minibus, taxi formed the greatest number of smokers (82.9%) among all drivers (p=0.023). The average of body mass index (BMI) was 26.2±4.06. The most prevalence of Mets according to IDF criteria were observed in drivers of heavy vehicles and also the ones of passenger vehicles, with 36.7% and 43.9% respectively. Based on high prevalence of Met Syn and other risk factors in this study, and considering these factors, should be more careful about this point. It is recommended to control risk factors such as, control of high BMI and TG, LDL, waist circumfernce, education.

Long working hours and alcohol use: systematic review and meta-analysis of published studies and unpublished individual participant data

OBJECTIVE

To quantify the association between long working hours and alcohol use.

DESIGN

Systematic review and meta-analysis of published studies and unpublished individual participant data.

DATA SOURCES

A systematic search of PubMed and Embase databases in April 2014 for published studies, supplemented with manual searches. Unpublished individual participant data were obtained from 27 additional studies.

REVIEW METHODS

The search strategy was designed to retrieve cross sectional and prospective studies of the association between long working hours and alcohol use. Summary estimates were obtained with random effects meta-analysis. Sources of heterogeneity were examined with meta-regression.

RESULTS

Cross sectional analysis was based on 61 studies representing 333,693 participants from 14 countries. Prospective analysis was based on 20 studies representing 100,602 participants from nine countries. The pooled maximum adjusted odds ratio for the association between long working hours and alcohol use was 1.11 (95% confidence interval 1.05 to 1.18) in the cross sectional analysis of published and unpublished data. Odds ratio of new onset risky alcohol use was 1.12 (1.04 to 1.20) in the analysis of prospective published and unpublished data. In the 18 studies with individual participant data it was possible to assess the European Union Working Time Directive, which recommends an upper limit of 48 hours a week. Odds ratios of new onset risky alcohol use for those working 49-54 hours and ≥ 55 hours a week were 1.13 (1.02 to 1.26; adjusted difference in incidence 0.8 percentage points) and 1.12 (1.01 to 1.25; adjusted difference in incidence 0.7 percentage points), respectively, compared with working standard 35-40 hours (incidence of new onset risky alcohol use 6.2%). There was no difference in these associations between men and women or by age or socioeconomic groups, geographical regions, sample type (population based v occupational cohort), prevalence of risky alcohol use in the cohort, or sample attrition rate.

CONCLUSIONS

Individuals whose working hours exceed standard recommendations are more likely to increase their alcohol use to levels that pose a health risk.

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.

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.

Association among Working Hours, Occupational Stress, and Presenteeism among Wage Workers: Results from the Second Korean Working Conditions Survey

Objectives

The purpose of the present study was to identify the association between presenteeism and long working hours, shiftwork, and occupational stress using representative national survey data on Korean workers.

Methods

We analyzed data from the second Korean Working Conditions Survey (KWCS), which was conducted in 2010, in which a total of 6,220 wage workers were analyzed. The study population included the economically active population aged above 15 years, and living in the Republic of Korea. We used the chi-squared test and multivariate logistic regression to test the statistical association between presenteeism and working hours, shiftwork, and occupational stress.

Results

Approximately 19% of the workers experienced presenteeism during the previous 12 months. Women had higher rates of presenteeism than men. We found a statistically significant dose–response relationship between working hours and presenteeism. Shift workers had a slightly higher rate of presenteeism than non-shift workers, but the difference was not statistically significant. Occupational stress, such as high job demand, lack of rewards, and inadequate social support, had a significant association with presenteeism.

Conclusions

The present study suggests that long working hours and occupational stress are significantly related to presenteeism.

Relationship between shift work and clustering of the metabolic syndrome diagnostic components

AIM

To examine the relationship between the type of work and the number of metabolic syndrome diagnostic components(MetS-DC), as well as the risk of MetS, with adjustment for lifestyle habits in Japanese workers.

METHODS

We examined the baseline data from 4,427 participants(81.4% male) aged 19 to 69 years old. The physical activity of each participant was classified according to the International Physical Activity Questionnaire(IPAQ). We defined the four MetS-DC in this study as follows: 1) high blood pressure(BP): systolic BP ≥130 mmHg, or diastolic BP ≥85 mmHg, or the use of antihypertensive drugs; 2) dyslipidemia: high-density lipoprotein-cholesterol concentration ＜40 mg/dl or triglyceride concentration ≥150 mg/dl, or on medication for dyslipidemia; 3) dysglycemia: fasting blood sugar level ≥110 mg/dl, or if less than eight hours after meals ≥140mg/dl, or on medication for diabetes mellitus; 4) overweight: a body mass index ≥25kg/m(2). We defined MetS as overweight plus two or more of the MetS-DC.

RESULTS

There were 3,094 subjects in the daytime work group, 73 in the fixed nighttime work group, 1,017 in the shift work group and 243 in the day-to-night work group. The Poisson regression analysis revealed that fixed nighttime (regression coefficient [b]=-0.233, P=0.028) and shift work (b=0.098, P=0.034) independently contributed to the number of MetS-DC, compared to daytime work. The multivariate logistic analysis not including sleep hours in the model showed that shift work was positively related to MetS (odd ratio=1.47, P＜0.01).

CONCLUSION

Shift work were significantly associated with the number of MetS-DC, and was related to risk of MetS compared to daytime work.