Association between long working hours and sleep problems in white-collar workers

Shiftwork, long working hours and markers of inflammation in a national US population-based sample of employed black and white men and women aged ≥45 years

OBJECTIVES

Work schedule demands contribute to circadian disruption and may influence health via an inflammatory response. We examined the impact of shiftwork and long work hours on inflammation in a national US sample.

METHODS

Participants included 12 487 employed black and white men and women aged ≥45 years enrolled in the REasons for Geographic and Racial Differences in Stroke Study who completed an occupational questionnaire (2011-2013) and clinical examination (2013-2016). Cross-sectional associations between shiftwork and work hours with log-transformed high-sensitivity C reactive protein (CRP) and white blood cell (WBC) count were examined by multiple linear regression analysis, overall and by race-sex subgroups.

RESULTS

Overall, rotating shift workers had higher log-CRP concentration compared with day workers (β=0.09, 95% CI:0.02 to 0.16) and findings for WBC were null. Black women had the highest geometric mean CRP (2.82 mg/L), while white men had the highest WBC (6.35×109/L). White men who worked afternoons had higher log-CRP compared with those who worked days (β=0.20, 95% CI: 0.08 to 0.33). Black men engaged in shiftwork <10 years working ≥55 hours/week had higher log-CRP and log-WBC compared with those working days <55 hours/week (β=0.33, 95% CI: 0.02 to 0.64 and β=0.10, 95% CI: 0.003 to 0.19). Among shift workers, non-retired white women working forward and backward shift rotations had higher log-CRP compared with those working forward only (β=0.49, 95% CI: 0.02 to 0.96).

CONCLUSIONS

Shift workers had higher inflammatory markers compared with day workers and race-sex disparities should be examined further. These findings highlight a potential biological pathway linking work schedule demands and chronic disease.

Examining the relationship between long working hours and the use of prescription sedatives among U.S. workers

OBJECTIVES

The prevalence of long working hours has been accompanied by a corresponding rise in sleep disorders. Sedative-hypnotic agents (SHAs), have been reported as the second most commonly misused drug class in the U.S. The key objective of this study was to examine the relationship between working hours on the use of sleep aids and medications with sedative properties.

METHODS

The 2010-2019 Medical Expenditure Panel Survey data was utilized. SHAs and medications with sedative related properties (MSRPs) were identified. Furthermore, we employed different regression models ranging from multivariable linear regression, Tobit regression, Heckman regression, and multivariable logistic regression, to ensure consistency, robustness, and reliability of associations.

RESULTS

Overall, a sample of 81,518 observations of full-time workers was analyzed. Working 56hours or more per week was significantly associated (p < 0.05) with an increased odds of using SHAs and MSRPs by 13% (Adjusted Odds Ratio, aOR =1.13, 95% Confidence Interval, CI=1.01:1.26) and 9% (aOR=1.09, 95% CI=1.03:1.16), respectively more than that among those who worked fewer hours. Females in our study had a higher likelihood (aOR=1.11, 95% CI=1.05:1.19) of using SHAs when compared to males. Also, professional services had the highest likelihood (aOR=1.31, 95% CI=1.14:1.50) of using SHAs.

CONCLUSION

We found that long working hours were significantly associated with an elevated use of SHAs and MSRPs among U.S. workers. Specifically, female workers and individuals working in professional services had the highest likelihood of using sleep medications.

Longitudinal Trends in Sleep and Related Factors Among South Korean Adults From 2009 to 2018

BACKGROUND AND PURPOSE

Excess or insufficient sleep, irregular sleep-wake patterns, and an extreme early or late chronotypes adversely impact physical and mental health. Changes in sleep characteristics should therefore be tracked, and factors that contribute to poor sleep should be identified. We investigated the changes in sleep patterns among South Korean adults during 2009-2018.

METHODS

Using data of a representative sample of South Korean adults from the 2009 (n=2,658, 48.5% males; age=44.5±15.0 years old [mean±standard deviation], age range=19-86 years) and 2018 (n=2,389, 49.1% males; age=47.9±16.3 years, age range=19-92 years) Korean Headache-Sleep Study, we explored changes in sleep timing, sleep duration, chronotype, and social jetlag (SJL). Logistic regression analysis was used to examine the association between average sleep duration and depression.

RESULTS

From 2009 to 2018, bedtimes were advanced by 10 and 25 min on workdays and free days, respectively. Meanwhile, wake-up times were advanced by 13 min and delayed by 12 min on workdays and free days, respectively. The average sleep duration significantly decreased from 7.45 h to 7.13 h. The prevalence of short sleep duration (<7 h) increased, whereas that of long sleep duration (≥8 h) decreased. A circadian preference toward eveningness and SJL increased. The prevalence of depression increased from 4.6% to 8.4%, and there were significant reverse J-shaped and U-shaped associations between average sleep duration and depression in 2009 and 2018, respectively.

CONCLUSIONS

Changes in sleep patterns and the association between sleep duration and depressive mood were determined from a representative sample of the South Korean adult population. Interventions to modify sleep behaviors might improve public health.

Longer working hours and musculoskeletal pain: a meta-analysis

Objectives. Musculoskeletal pain is the most common health problem in the workplace, and one of the most important risk factors for this pain is longer working hours. This study aimed to investigate the association between long working hours and musculoskeletal pain. Methods. Based on the keywords, two scientific sources - PubMed and Embase - were reviewed. The time limit search included articles that were published until May 2020 and only studies published in English were eligible. The results of the studies were combined based on random effects and pooled odds ratio (OR) reported. The degree of heterogeneity in all analyses was investigated and reported based on χ² and I² tests. Publishing bias was also measured using statistical tests. Results. Longer working hours are associated with increased musculoskeletal pain with OR = 1.11 and 95% confidence interval (CI) [1.08, 1.14]. The result was OR = 1.52 and 95% CI [1.14, 2.03] in men and OR = 1.11 and 95% CI [1.00, 1.24] in women. Conclusion. Long working hours are an important and threatening factor for musculoskeletal health. Therefore, this issue should be considered in health policy as well as treatment and prevention.

From good sleep to health and to quality of life – a path analysis of determinants of sleep quality of working adults in Abu Dhabi

Background

Sleep quality has significant impacts on many aspects of quality of life. Therefore, identifying the association of sleep quality with that quality of life domains could lead to deeper insights for social policymakers and professionals to enhance their understanding of the lives of Abu Dhabi working adults. This research focuses on sleep quality among working people in Abu Dhabi. The direct and indirect associations of sleep quality with various quality-of-life domains such as income and housing, physical and mental health, sport and activities, eating habits and obesity, work-life balance, online hours, and social connections are investigated and discussed.

Methods

Data were drawn from 36,515 full-time employees in both public, and private sectors, obtained from the third Abu Dhabi Quality of Life (QoL) survey aimed to cover all community members using online platforms. Informed by international research on sleep quality, preliminary investigation using correlation analysis and simple regression identified many well-being variables deemed necessary for inclusion in the path model. Path analysis was then performed.

Results

The final path model produced excellent fit measures. The significant variables directly associated with sleep quality included sleeping hours, social connection, satisfaction with income, satisfaction with residence, subjective physical and mental health, income satisfaction, satisfaction with the surrounding environment, frequency of eating healthy food, work-life balance, and online time. In addition, most variables recorded an indirect association to sleep quality through subjective health.

Conclusions

The importance of multidimensional linkages between many well-being factors influencing sleep quality and subjective health is underscored.

The association of stress and work hours with sleep duration and insomnia symptoms among U.S.-born and Foreign-born Black adults

OBJECTIVE

To examine associations between stress and work hours with sleep duration and insomnia symptoms among U.S.-born and Foreign-born Black adults.

DESIGN

A cross-sectional analysis of the National Health Interview Survey.

PARTICIPANTS

Black adults (N = 16,315) with a mean age of 40 ± 0.1 years, mostly women (52.7%), college graduates (40.7%), and U.S.-born (82.5%).

MEASUREMENTS

Participants self-reported sleep duration, insomnia symptoms, frequent stress (yes/no), and work hours in the prior week (1-39 hours, 40 hours, ≥41 hours). Poisson regression with robust variance was used to test associations overall and by nativity.

RESULTS

Working ≥41 hours, frequent stress, and short sleep duration (<7 hours) were reported by 22%, 24.9%, and 43% of participants, respectively. U.S.-born and Foreign-born Black adults who reported frequent stress and working ≥41 hours vs. 40 hours had 60% and 19% higher prevalence of short sleep duration (adjusted prevalence ratio [aPR] = 1.60, 95% confidence interval [CI]: 1.47, 1.74 and aPR = 1.19, 95% CI: 1.12, 1.25, respectively). Foreign-born Black adults who worked 1-39 hours vs. 40 hours, had higher prevalence of short sleep duration, aPR = 1.18, 95% CI: 1.01, 1.37. U.S.-born Black adults who worked ≥41 hours vs. 40 hours had higher prevalence of insomnia symptoms (trouble falling asleep: aPR = 1.33 [95% CI: 1.13, 1.56], trouble staying asleep: aPR = 1.33 [95% CI: 1.16, 1.53]).

CONCLUSION

Frequent stress and working ≥41 hours are likely salient determinants of sleep health for U.S. and Foreign-born Black individuals. Further, less work hours (Foreign-born) while longer work hours (U.S.-born) were associated with short sleep duration. Stress and work hours may be factors for sleep health interventions among Black adults.

Relationship between burnout, effort-reward imbalance, and insomnia among Informational Technology professionals

BACKGROUND

Work in informational technology (IT) professionals is highly competitive and stressful, leading to job stress. This can lead to burnout, effort-reward imbalance (ERI), and poor sleep quality.

MATERIALS AND METHODS

The present study examined associations of ERI, burnout, and poor sleep quality among IT professionals using data from 200 software engineers (mean age of 29.3 ± 4 years, 32% women). ERI and overcommitment were assessed using Siegrist's "effort-reward" questionnaire. The Oldenburg Burnout Inventory (OLBI) was used to assess burnout and Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality.

RESULTS

ERI, burnout and poor sleep quality were present in 72%, 60%, and 70%, respectively. Females had higher ERI, burnout, and poor sleep quality compared to males. ERI is significantly associated with burnout (r = 0.45, P < 0.01) and poor sleep quality (r = 0.31, P < 0.01). Linear regression to assess the ability of ERI to predict levels of burnout yielded a statistically significant (R ² = 0.206, P < 0.01) indicating ERI to be a unique incremental predictor of burnout (b = 0.454, t = 7.16, P < 0.01). ERI tends to be a predictive factor of poor sleep quality with Odd's ratio = 3.5, 95%CI (1.81-6.73), P < 0.01.

CONCLUSION

In summary, Intervention programs both at the individual and at the organization level have to be designed to combat ERI, burnout, and poor sleep quality among IT professionals.

Work schedule characteristics associated with sleep disturbance among healthcare professionals in Europe and South Korea: a report from two cross-sectional surveys

Background

Healthcare professionals worldwide are prone to sleep disturbance. Such sleep disturbance is associated with lower patient safety and quality of care. Therefore, this study aimed to identify the prevalence of sleep disturbance and determine the effect of work schedule characteristics on sleep disturbance among healthcare professionals in Europe and South Korea.

Methods

We used the sixth European Working Conditions Survey and the fifth Korean Working Conditions Survey for analyses. The study included 2285 healthcare professionals aged 18–65 years. Work schedule characteristics included shift work, night work, working hours per week, long work hours (i.e., more than 10 hours per shift), quick return to work, having to come to work on short notice, and changes in work schedules. A multiple logistic regression analysis was performed.

Results

The overall prevalence of sleep disturbance was 37.7%. The multivariate logistic regression model indicated that long work hours, quick return to, having to come to work on short notice, and changes in work schedules were significant factors associated with sleep disturbance among healthcare professionals.

Conclusion

The findings revealed that several work schedule-related factors were associated with sleep disturbances in healthcare professionals in Europe and Korea. Institutions and policymakers should implement strategies and policies to reduce the unpredictability of work schedules to ensure an adequate rest period between shifts and to reduce sleep disturbances.

How the reduction of working hours could influence health outcomes: a systematic review of published studies

OBJECTIVES

The health effects of work-time arrangements have been largely studied for long working hours, whereas a lack of knowledge remains regarding the potential health impact of reduced work-time interventions. Therefore, we conducted this review in order to assess the relationships between work-time reduction and health outcomes.

DESIGN

Systematic review of published studies. Medline, PsycINFO, Embase and Web of Science databases were searched from January 2000 up to November 2019.

OUTCOMES

The primary outcome was the impact of reduced working time with retained salary on health effects, interventional and observational studies providing a quantitative analysis of any health-related outcome were included. Studies with qualitative research methods were excluded.

RESULTS

A total of 3876 published articles were identified and 7 studies were selected for the final analysis, all with a longitudinal interventional design. The sample size ranged from 63 participants to 580 workers, mostly from healthcare settings. Two studies assessed a work-time reduction to 6 hours per day; two studies evaluated a weekly work-time reduction of 25%; two studies evaluated simultaneously a reduced weekly work-time reduction proportionally to the amount of time worked and a 2.5 hours of physical activity programme per week instead of work time; one study assessed a reduced weekly work-time reduction from 39 to 30 hours per week. A positive relationship between reduced working hours and working life quality, sleep and stress was observed. It is unclear whether work time reduction determined an improvement in general health outcomes, such as self-perceived health and well-being.

CONCLUSIONS

These findings suggest that the reduction of working hours with retained salary could be an effective workplace intervention for the improvement of employees' well-being, especially regarding stress and sleep. Further studies in different contexts are needed to better evaluate the impact of work-time reduction on other health outcomes.

Work-related stress and well-being in association with epigenetic age acceleration: A Northern Finland Birth Cohort 1966 Study

Recent evidence indicates consistent association of low socioeconomic status with epigenetic age acceleration, measured from DNA methylation. As work characteristics and job stressors are crucial components of socioeconomic status, we investigated their association with various measures of epigenetic age acceleration. The study population included employed and unemployed men and women (n=604) from the Northern Finland Birth Cohort 1966. We investigated the association of job strain, effort-reward imbalance and work characteristics with five biomarkers of epigenetic aging (Hannum, Horvath, PhenoAge, GrimAge, and DunedinPoAm). Our results indicate few significant associations between work stress indicators and epigenetic age acceleration, limited to a range of ±2 years, and smoking recording the highest effect on GrimAge age acceleration biomarker between current and no smokers (median difference 4.73 years (IQR 1.18, 8.41). PhenoAgeAA was associated with job strain active work (β=-1.301 95%CI -2.391, -0.212), slowing aging of less than 1.5 years, and working as white-collar slowed aging six months (GrimAgeAA β=-0.683, 95%CI -1.264, -0.102) when compared to blue collars. Association was found for working for more than 40 hours per week that increased the aging over 1.5 years, (HorvathAA β =2.058 95%CI 0.517,3.599, HannumAA β=1.567, 95%CI 0.415,2.719). The pattern of associations was different between women and men and some of the estimated effects are inconsistent with current literature. Our results provide the first evidence of association of work conditions with epigenetic aging biomarkers. However, further epidemiological research is needed to fully understand how work-related stress affects epigenetic age acceleration in men and women in different societies.

Cohort study of long working hours and increase in blood high-sensitivity C-reactive protein (hsCRP) concentration: Mechanisms of overwork and cardiovascular disease

OBJECTIVES

We aimed to find evidence of the inflammation-mediated mechanism by which long working hours contribute to cardiovascular disease (CVD).

METHODS

This cohort study was performed in 56 953 Korean adults free of CVD who underwent a comprehensive screening examination and were followed for up to 7 years. An increase in blood high-sensitivity C-reactive protein (hsCRP) of 1 mg/L or more at the follow-up visit was defined as an incidence. The average weekly working hours in the past year were categorized as ≤40, 41-52, 53-60, and ≥60 h per week. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using generalized estimating equations to calculate the risk of an incidental increase of hsCRP.

RESULTS

Participants with longer working hours had a higher incidence of hsCRP. Multivariable-adjusted ORs (95% CIs) of incident cases for ≥61 h compared with ≤40 h was 1.69 (1.04-2.75). In subgroup analyses according to sex and the presence of hypertension and diabetes, the risk of hsCRP incidence were highest in the group working more than 61 h in all subgroups, but none of them were statistically significant.

CONCLUSIONS

Working hours are independently associated with increased risk of elevated hsCRP in a dose-response relationship. Excessive long-time work is a risk factor for CVD, and it was found that an increase in hsCRP was associated with the pathogenesis.

The relationship between occupational stressors and insomnia in hospital nurses: The mediating role of psychological capital

Background

Nurses have a high incidence of insomnia. Insomnia not only damages the physical and mental health of nurses, but also reduces their productivity and quality of care, ultimately affecting patient care. Over the past 30 years, a large number of epidemiological surveys have shown that insomnia in nurses is associated with occupational stress. As an external feature of the role of a nurse, occupational stress is difficult to alter in a short period of time. Therefore, it is necessary to discuss the complex mediating variables in the relationship between occupational stress and insomnia in nurses in order to find different ideas to address the problem of insomnia caused by occupational stress. Psychological capital, the positive psychological strength of an individual, has been widely used in previous reports as a mediating variable between occupational stress and adverse psychological problems.

Objective

This study aimed to explore the mediating effect of psychological capital on occupational stressors and insomnia among Chinese nurses.

Methods

The Strengthening the Reporting of Observational Studies in Epidemiology statement was referred to conduct the study. A cross-sectional stratified sampling method was used to recruit 720 participants from a tertiary hospital in Jinan, Shandong province, located in the east of China, from June to August 2019. Questionnaires were used to obtain data on demographic variables, psychological capital, occupational stressors, and insomnia.

Results

The study findings revealed that work settings [department (F = 3.08, p = 0.006), working hours per week (t = -2.03, p = 0.043) and shift work (t = 3.66, p < 0.001)], decision latitude (r = -0.25, p < 0.001), psychological job demand (r = 0.15, p < 0.001), social support (r = -0.31, p < 0.001), and psychological capital (r = -0.40, p < 0.001) were differentially associated with insomnia experiences. This cross-sectional survey showed that psychological capital has significant mediation effects on the relationship between occupational stressors and insomnia. In the model of decision latitude - psychological capital - insomnia, the mediating effect was-0.04 (95%CI: -0.07 ~ -0.02), accounting for 50.0% of the total effect; In the model of job demands - psychological capital - insomnia, the mediating effect was 0.03 (95%CI: 0.01 ~ 0.06), accounting for 25.0% of the total effect; In the model of social support - psychological capital - insomnia, the mediating effect was -0.11 (95%CI: -0.16 ~ -0.07), accounting for 39.0% of the total effect.

Conclusion

Psychological capital not only had a direct effect on both occupational stressors and insomnia, but also played mediating roles in relationship between occupational stressors and insomnia. It has been suggested that nurses themselves and nursing managers should improve the psychological capital of nurses by various means to alleviate the effects of occupational stress on nurses' insomnia.

A Cross-Sectional Study on the Relationship Among Cytokines, 5-HT2A Receptor Polymorphisms, and Sleep Quality of Non-manual Workers in Xinjiang, China

BACKGROUND

Studies have shown that cytokine activity changes during the sleep-wake process, suggesting that inflammatory factors may be involved in a mechanism affecting sleep quality. Furthermore, the serotonergic system is also one of the essential components of airway relaxation during sleep, especially the serotonin 2A receptor (5-HTR2A) type that plays an important role in the sleep-wake process. Therefore, this research aimed to investigate the effects of cytokines and 5-HTR2A polymorphisms on sleep quality in non-manual workers in Urumqi, Xinjiang in order to explore the relationship between the three.

METHODS

This study used a cluster sampling method to randomly select non-manual workers who worked in Urumqi, Xinjiang for at least 1 year. From July 2016 and December 2017, this study recruited 1,500 non-manual workers for physical examination in the First Affiliated Hospital of Xinjiang Medical University. According to the inclusion and exclusion criteria, 1,329 non-manual workers were finally included in the questionnaire study. It used the Pittsburgh Sleep Quality Index questionnaire to assess sleep quality. Moreover, another 15% of respondents were randomly selected as the experimental study group. The polymerase chain reaction restriction fragment length polymorphism was used to detect 5-HTR2A gene genotypes. Simultaneously, the cytokine (IL-1β, IL-2, IL-6, and TNF-α) content was evaluated using an enzyme-linked immunoassay.

RESULTS

The results showed that among the 1,329 respondents, 870 had sleep quality problems, and the detection rate was 65.46%. The distribution of -1438G/A genotypes in the 5-HTR2A gene was significantly different among different sleep quality groups (p < 0.05), with no statistical significance present when comparing to T102C (p > 0.05). Logistic regression analysis showed that the AG [odds ratio (OR) = 2.771, 95% confidence interval (CI): 1.054-7.287] and GG (OR = 4.037, 95% CI: 1.244-13.105) genotypes at -1438G/A loci were both associated with poor sleep quality and were thus considered the susceptibility genotypes for sleep problems. Furthermore, IL-1β was shown to be a protective factor for sleep quality (OR = 0.949, 95% CI: 0.925-0.974). The interaction results showed that AG × IL-1β (OR = 0.952, 95% CI: 0.918-0.987) was associated with a lower risk of sleep problems than AA × IL-1β.

CONCLUSION

Cytokines and 5-HTR2A polymorphisms not only have independent effects on sleep but also may have cumulative effects. Therefore, it is necessary to further explore the related mechanisms affecting sleep quality to improve the sleep quality of non-manual workers.

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.

Working hours are closely associated with depressive mood and suicidal ideation in Korean adults: a nationwide cross-sectional study

Long working hours have been presumed to negatively influence health. However, evidence is lacking regarding any associations of working hours with depressive mood or suicidal ideation. We investigated the relationships of working hours with depressive mood and suicidal ideation in a representative sample of the Korean general population. We analyzed data collected by the Korea National Health and Nutrition Examination Surveys VI and VII (2013–2018). Depressive mood and suicidal ideation were identified through self-reporting. We divided participants into four groups according to weekly working hours: 30–40, 41–50, 51–60, and > 60 h/week. Sampling weights were applied to obtain estimates for the general Korean population. We analyzed 14,625 participants, of whom 5383 (36.8%), 4656 (31.8%), 2553 (17.5%), and 2033 (13.9%) worked 30–40, 41–50, 51–60, and > 60 h/week, respectively. In these groups, 3.6%, 4.4%, 5.2%, and 6.3% of the participants reported depressive mood, while 1.8%, 1.9%, 2.2%, and 3.6% reported suicidal ideation. In multiple regression analyses, compared with the 30–40 h/week group, the adjusted odds ratios of the 41–50, 51–60, and > 60 h/week groups for depressive mood were 1.35 (1.08–1.69), 1.5 (1.14–1.97), and 1.6 (1.19–2.14). A similar trend was evident for suicidal ideation (odds ratios 1.16 [0.82–1.63], 1.48 [0.99–2.21], and 2.29 [1.53–3.42]). Long working hours are significantly associated with depressive mood and suicidal ideation.

Association between self-reported sleep duration and cardiometabolic risk in corporate executives

PURPOSE

This cross-sectional study aimed to compare the association between self-reported sleep duration and cardiometabolic risk among men and women corporate executives and investigate potential lifestyle, work- and stress-related mediators thereof.

METHODS

Self-reported sleep duration and lifestyle, occupational, psychological and measured anthropometrical, blood pressure (BP) and blood marker variables were obtained from health risk assessment data of 3583 corporate executives. Sex-stratified regression analyses investigated the relationships between occupational and psychological variables with self-reported sleep duration, and sleep duration with individual cardiometabolic risk factors. Mediation analyses investigated the effects of work, psychological and lifestyle factors on the relationships between self-reported sleep duration and cardiometabolic risk factors, as well as a continuous cardiometabolic risk score calculated from the sum of sex-stratified z-standardized scores of negative fasting serum HDL, and positive plasma Glu, serum TG, body mass index (BMI), waist circumference, systolic and diastolic BP.

RESULTS

Longer work hours and work commute time, depression, anxiety and stress were associated with shorter sleep duration in both men and women (all p < 0.05). Shorter sleep duration was associated with higher BMI, larger waist circumference and greater cardiometabolic risk scores in both men and women (all p < 0.05), higher diastolic BP in men (p < 0.05) and lower HDL cholesterol in women (p < 0.05). Physical activity, working hours and stress significantly mediated the relationships between self-reported sleep duration and BMI, waist circumference, diastolic BP and cardiometabolic risk score in men only.

CONCLUSION

In these corporate executives, shorter self-reported sleep duration is associated with poorer psychological, occupational and cardiometabolic risk outcomes in both men and women. Given that physical activity, working hours and stress mediate this association among the men, the case for sleep health interventions in workplace health programmes is warranted.

Association Between Overtime-Working Environment and Psychological Distress Among Japanese Workers: A Multilevel Analysis

Supplemental Digital Content is available in the text

Objective:

The study aims to examine the association between overtime-working environment (OWE) and individual psychological distress among Japanese workers.

Methods:

Data of 7786 workers from 101 companies in Japan were analyzed. Psychological distress was assessed through a 29-item questionnaire. The OWE was evaluated by calculating the proportion of workers whose monthly overtime was 45 hours or more in a workplace. Multilevel logistic regression was used.

Results:

As 10% increase in the OWE was associated with a 16% higher risk of individual psychological distress after adjustment of individual covariates, including overtime working hours. Cross-level interaction showed that the risk was varied depending on individual overtime working hours.

Conclusions:

OWE was associated with the psychological distress of workers. It is necessary to create a non-OWE at workplaces to prevent psychological distress for workers.

The interplay of sleep duration, working hours, and obesity in Korean male workers: The 2010-2015 Korea National Health and Nutrition Examination Survey

The purpose of this study was to clarify the odds ratio for association between working hours and obesity in Korean male wage workers and investigate the role of sleep duration. This study is a cross-sectional one using large-scale national data from the Korea National Health and Nutrition Examination Survey collected between 2010 and 2015 to evaluate 2,592 male wage workers (between the ages of 19 and 60 years). Obesity was defined as 25kg/m² or more and working hours per week were categorized into <40, 40–49, 50–59, and ≥60 hours. Multiple regression analysis was performed to examine the odds ratio for association between working hours and obesity, after controlling for age, education, income, marital status, smoking, drinking, physical activity, daily energy intake, sleep duration, hypertension, diabetes, dyslipidemia, work schedule, and job category. Next, to study the mediating effect of sleep duration on the association between working hours and obesity, an analysis was performed using the Baron and Kenny method and the Sobel test. Results showed that workers with 50 to 59 hours had 1.4 times higher odds (odds ratio [OR] = 1.4, confidence interval [CI]: 1.11–1.85) of obesity and workers with 60 hours or more had 1.4 times higher odds (OR = 1.4, CI: 1.06–1.90) of obesity than workers with less than 40 hours. Sleep was found to have a mediating effect on the association between working time and body mass index. Therefore, the results of this analysis suggest that practitioners should identify potential factors such as working time and sleeping time when preventing work-related obesity.

Irregular Work Hours and the Risk of Sleep Disturbance Among Korean Service Workers Required to Suppress Emotion

Although a necessity in a modern society, irregular work schedule can lead to sleep problems. We investigated the effect of work schedule irregularity on sleep disturbance of 17,846 Korean service workers using the fifth Korean Working Conditions Survey. The odds ratio (OR) and 95% confidence interval (CI) for sleep disturbance occurrence were calculated through a multiple logistic regression model. The adjusted ORs for moderate and severe sleep disturbances for those with irregular work hours were 2.11 (95% CI 1.90–2.33) and 3.10 (95% CI 2.62–3.66), respectively. Work schedule irregularity and emotion suppression at work showed synergistic effect on both moderate and severe sleep disturbances. Sleep disturbances can lead to brain function deterioration and work-related injuries; therefore, appropriate measures should be addressed for the vulnerable population.

Prevalence of Poor Sleep Quality Among Physicians During the COVID-19 Pandemic

BACKGROUND

Sleep quality is influenced adversely or favorably by various intrinsic and extrinsic factors and sleep deprivation is a common problem facing doctors.

OBJECTIVES

To assess sleep quality among physicians during coronavirus disease 2019 (COVID-19) pandemic and correlate it with possible predictors.

METHODS

This cross-sectional four-months study included a total of 344 physicians from different medical centers in the period between July 2020 and October 2020, during the COVID-19 pandemic. Physicians were aged between 24 and 60 years from different specialties. Data were collected using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and Hospital Anxiety Depression Scale (HADS).

RESULTS

Among our participant physicians there was poor sleep quality in 71.2%, while good sleep quality was present in 28.8%. There were significant correlations between poor sleep quality and the following parameters in the univariate logistic regression analysis: anxiety features (P value <0.001), depressive features (P value <0.001), and past history of COVID-19 (P value 0.003). However, multivariate logistic regression analysis showed that only the presence of anxiety features (P value <0.001) and depressive features (P value <0.001) could be used as significant independent predictor of poor sleep quality among physicians during COVID-19.

CONCLUSION

Presence of anxiety and or depressive features among physicians are the most significant independent predictors of poor sleep quality during the COVID-19 pandemic.

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

Background

Methods

Results

Conclusion

The relationship between working hours and lifestyle behaviors: Evidence from a population-based panel study in Korea

OBJECTIVES

This study aimed to investigate the relationship between working hours and lifestyle behaviors using data from a large nationally representative panel survey.

METHODS

We used the Korea Health Panel Study (KHPS) data from 2011 to 2014. Weekly working hours and lifestyle risk factors were assessed by questionnaires. Comparing to the reference group, the weekly working hours were 40 h per week, odds ratios and 95% confidence intervals for smoking status, alcohol consumption status, and regular exercise status of other weekly working hours groups (<40, 40, 41-52, and >52) were calculated, using generalized estimating equation models considering repeated measures.

RESULTS

Our findings clearly showed a relationship between long working hours and unhealthy lifestyles, such as cigarette smoking, alcohol consumption, physical inactivity, and insufficient sleep. Additionally, weekly working hours are positively associated with the amount of smoking and drinking, and inversely associated with sleep duration among those who worked 40 h or more per week.

CONCLUSION

Long working hours are associated with unhealthy lifestyles, such as cigarette smoking, alcohol consumption, physical inactivity, and insufficient sleep.

Passion for an activity: a new predictor of sleep quality

STUDY OBJECTIVES

The present research examines the relationship between people's frequent involvement in an activity they like and find important (i.e., a passion) and the quality of their sleep. Research on the dualistic model of passion has widely documented the relationship between individuals' type of passion-harmonious versus obsessive-and the quality of their mental and physical health. However, research has yet to examine the relationship between passion and sleep quality. Building on prior research has shown that obsessive (vs harmonious) passion is related to depressive mood symptoms-an important factor associated with sleep problems-we hypothesized that obsessive passion would be associated with overall worse sleep quality, whereas harmonious passion would predict better sleep quality.

METHODS

A sample of 1,506 Americans filled out an online questionnaire on sleep habits and passion. Sleep quality was measured using the Pittsburgh Sleep Quality Index. Hierarchical linear regressions and mediation analyses were carried out with results confirming our hypotheses.

RESULTS

Obsessive passion for an activity was associated with worse sleep quality, whereas harmonious passion was associated with better sleep quality, adjusting for demographics, the type of passionate activity and its self-reported importance, alcohol and tobacco consumption, BMI, self-reported health, and diagnosed health conditions. The relationship between both types of passion and sleep quality was mediated by depressive mood symptoms.

CONCLUSIONS

Our study presents evidence of a strong relationship between sleep quality and passion, opening the door for future research to create new interventions to improve people's sleep and, consequently, their well-being.

Suicidal ideation among nurses: Unique and cumulative effects of different subtypes of sleep problems

BACKGROUND

Nurses have high rates of sleep problems, and higher risk of suicide than the general population. However, there is no empirical evidence showing the extent to which sleep problems among nurses are related to suicidal ideation.

METHODS

Multistage stratified cluster sampling was performed to recruit nurses from tertiary hospitals in Shandong, China. Item 9 of the Patient Health Questionnaire-9 was used to assess suicidal ideation. The Pittsburgh Sleep Quality Index was used to assess different subtypes of sleep problems.

RESULTS

Overall prevalence of suicidal ideation among the sample was 10.8%. Nurses with sleep problems were at high risk for suicidal ideation (^bOR = 1.79, 95% CI = 1.20-2.65). Among different sleep problem subtypes, only "cannot breathe comfortably" was independently related to suicidal ideation. Different subtypes of sleep problems had cumulative effects on suicidal ideation: the more subtypes of sleep problems nurses experienced, the higher the likelihood of suicidal ideation.

LIMITATIONS

The cross-sectional study design prevents inferring causation, and the use of self-report measures may lead to recall bias. Other physical/mental conditions, besides depression, were not assessed. Statistical power may have been insufficient due to the small sub-sample who reported suicidal ideation. Also, the generalizability of the results is limited, as the sample only comprised nurses in tertiary hospitals.

CONCLUSIONS

Nurses experiencing sleep problems were associated with increased likelihood of suicidal ideation. It may be beneficial to incorporate sleep problems into routine screening and intervention for suicide prevention in clinical practice.

Relationship between Mental Health, the CLOCK Gene, and Sleep Quality in Surgical Nurses: A Cross-Sectional Study

Nursing is a high-risk occupation with high exposure to stress. The physical and mental health of nurses is directly related to the quality of medical services. Therefore, the sleep quality of nurses should not be ignored. In this study, the method of cluster random sampling was adopted from May to September 2019, and a questionnaire survey was conducted among 521 surgical nurses from five affiliated hospitals of Xinjiang Medical University. The relationship between mental health and sleep quality was analyzed, and 20% of the participants with sleep disorders were randomly selected. The sleep disorders used 1 : 1 matching, finally providing a sample with 60 cases and 60 controls for measurement of the CLOCK gene (rs1801260, rs6850524), to analyze the effect of the interaction between mental health and the CLOCK gene on sleep. The mental health and sleep quality of the surgical nurses were evaluated using the Symptom Checklist 90 (SCL-90) and Pittsburgh Sleep Quality Index (PSQI). The study found that surgical nurses had poor sleep, and there were differences associated with age, years working, frequency of night shifts, and incidence of sleep disorders under marital status (p < 0.05). The PSQI scores of the positive psychological symptoms were higher than those of the negative psychological symptoms. The rank sum test was used to compare the sleep quality scores of different genotypes in CLOCK rs1801260 and rs6850524; the results indicated that the PSQI scores were different among different genotypes at the rs1801260 and rs6850524 loci. The logistic regression results suggested that CLOCK gene rs1801260 (TC) and positive psychological symptoms were influential factors for sleep disorders, and the interaction of positive psychological symptoms∗rs1801260 (TT) was a risk factor for sleep disorders (OR = 10.833, 95% CI: 2.987-39.288). The sleep quality of nurses is not only affected by demographic characteristics but also affected by mental health status and the CLOCK gene.

How does cessation of work affect sleep? Prospective analyses of sleep duration, timing and efficiency from the Swedish Retirement Study

Several strands of research indicate that work competes for time with sleep, but to what extent the timing and duration of sleep is affected by work is not known. Retirement offers a quasi-experimental life transition to study this in a within-individual study design. The few existing studies report that people sleep longer and later after retirement but mainly rely on self-reported data or between-individual analyses. We recruited 100 participants aged 61-72 years who were in paid work but would soon retire and measured them in a baseline week with accelerometers, diaries and questionnaires. After 1 and 2 years, the measurements were repeated for the now retired participants. Changes in sleep duration, timing, efficiency, chronotype and social jetlag were analysed using multilevel modelling. Gender, chronotype at baseline and partner's working status were analysed as potential effect modifiers. Sleep duration increased by 21 min, whereas sleep efficiency remained similar. Time of sleep onset and final awakening were postponed by 26 and 52 min, respectively, pushing midsleep forward from 03:17 to 03:37 hours. Changes in duration and timing of sleep were driven by weekday sleep, whereas weekend sleep stayed about the same. Social jetlag decreased but still occurred after retirement. Changes at retirement in sleep duration and timing were smaller for participants with a later chronotype and who had full-time working partners. These findings indicate that paid work generates sleep loss and hinders people from sleeping in line with their biological time.

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.

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.

Relationships between insomnia, long working hours, and long commuting time among public school teachers in Japan: a nationwide cross-sectional diary study

OBJECTIVES

The present study aimed to clarify the prevalence and risk factors of insomnia among public school teachers in Japan by examining the relationships between working hours, commuting time, and insomnia. Time spent on work activities among teachers with insomnia was also investigated.

METHODS

This study was a secondary analysis of data obtained in a 2016 survey of working conditions among public elementary/junior high school teachers in Japan. A total of 11,390 teachers (women: 47.4%, average age: 42.2 ± 11.3 years) were selected for analysis. The relationships between working hours, commuting time, and insomnia were evaluated using a binomial logistic regression model. The primary outcome was insomnia, defined by a score of ≥6 on the Athens Insomnia Scale. Explanatory factors were working hours/week, commuting time/day, six subscales of occupational stress, age group, presence of children, type of job, type of the school, and the urbanicity of the school.

RESULTS

In total, 41.7% of men and 44.0% of women were classified into the insomnia group. The insomnia group spent more time preparing for lectures, and a significant association was observed between insomnia and long working hours and commuting time. Results of multivariate logistic regression analysis showed that long working hours, long commuting time, and urbanicity of the school were statistically significantly associated with insomnia.

CONCLUSIONS

Insomnia is common among public school teachers in Japan. Our findings suggest the importance of reducing the time spent on working to prevent insomnia.

The Combined Effect of Long Working Hours and Low Job Control on Self-Rated Health: An Interaction Analysis

Objectives:

The aim of this study was to investigate the combined effects of long working hours and low job control on self-rated health.

Methods:

We analyzed employees’ data obtained from the third Korean Working Conditions Survey (KWCS). Multiple survey logistic analysis and postestimation commands were employed to estimate the relative excess risk due to interaction (RERI).

Results:

The odds ratio (OR) for poor self-rated health was 1.24 [95% confidence interval (95% CI): 1.13 to 1.35] for long working hours, 1.04 (95% CI: 0.97 to 1.13) for low job control, and 1.47 (95% CI: 1.33 to 1.62) for both long working hours and low job control. The RERI was 0.18 (95% CI: 0.02 to 0.34).

Conclusion:

These results imply that low job control may increase the negative influence of long working hours on self-rated health.

Cross-Sectional Survey on the Relationship Between Occupational Stress, Hormone Levels, and the Sleep Quality of Oilfield Workers in Xinjiang, China

The impact of psychosocial factors on health has received increased attention. This study employed a multi-stage hierarchical cluster sampling method and a cross-sectional survey was conducted from March to August 2017. By studying 2116 oilfield workers based in Karamay, Xinjiang, the relationship between occupational stress, blood hormone levels, and sleep was analyzed. Occupational stress was measured using the internationally accepted Occupational Stress Inventory Revised Edition (OSI-R) questionnaire and sleep disorders were measured using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. The study found that the sleep quality of respondents was not high and the incidence of sleep disorders was 36.67%. The higher the level of occupational stress, the higher the incidence of sleep disorders. Irregular shifts can affect sleep quality and individuals with high-level professional titles experience a higher incidence of sleep disorders than those with low-level titles. The total score of the PSQI was different among the low, medium, and high stress groups. The higher the level of stress, the higher the scores of subjective sleep quality, sleep disorder, and daytime dysfunction. The scores of the PSQI, subjective sleep quality, sleep time, sleep disturbance, and daytime dysfunction in the high-stress group were higher than those in the low stress group. A case-control study found that the concentration of glucocorticoids in the sleep disorder positive group was lower than that in the sleep disorder negative group. The results of the regression analysis showed that glucocorticoid is a protective factor for sleep disorders (OR = 0.989, 95% CI: 0.983-0.995), suggesting that the higher the level of glycosaminoglycan, the less likely the subject is to have sleep disorders. For example, in the case of high occupational stress, the interaction between low and moderate occupational stress levels and glucocorticoids is a protective factor for sleep disorders.

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 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.

Are U.S. adults reporting less sleep?: Findings from sleep duration trends in the National Health Interview Survey, 2004-2017

Study Objectives

To document trends in self-reported sleep duration for the noninstitutionalized U.S. civilian population from 2004 to 2017 and examine how sleep trends vary by race/ethnicity.

Methods

We use data from the National Health Interview Survey (NHIS) for U.S. noninstitutionalized adults aged 18-84 from 2004 to 2017 (N = 398 382). NHIS respondents were asked how much they slept in a 24-hour period on average, which we categorized as ≤6 hr (short sleep), 7-8 hr (adequate sleep), and ≥9 hr (long sleep). We used multinomial logistic regression models to examine trends in self-reported sleep duration and assess race/ethnic differences in these trends. Our models statistically adjusted for demographic, socioeconomic, familial, behavioral, and health covariates.

Results

The prevalence of short sleep duration was relatively stable from 2004 to 2012. However, results from multinomial logistic regression models indicated that there was an increasing trend toward short sleep beginning in 2013 (b: 0.09, 95% CI: 0.05-0.14) that continued through 2017 (b: 0.18, 95% CI: 0.13-0.23). This trend was significantly more pronounced among Hispanics and non-Hispanic blacks, which resulted in widening racial/ethnic differences in reports of short sleep.

Conclusions

Recent increases in reports of short sleep are concerning as short sleep has been linked with a number of adverse health outcomes in the population. Moreover, growing race/ethnic disparities in short sleep may have consequences for racial and ethnic health disparities.

Relationships Between Chronic Musculoskeletal Pain and Working Hours and Sleeping Hours: A Cross-sectional Study

Ten to twenty percent of the population of Japan has chronic pain. Although studies have confirmed a relationship between sleeping hours and chronic pain, it remains unclear whether there is an association between working hours and chronic pain, especially chronic musculoskeletal pain (CMP), in workers. A self-administered questionnaire that sought information regarding background characteristics and work-related factors was sent to 118 enterprises; finally, 1,747 participants were included in the analysis and were classified into CMP (n = 448) and non-CMP (n = 1299) groups. Logistic regression analysis revealed that age (odds ratio [OR] = 1.02, 95% confidence interval [CI]: 1.01-1.03), sex (reference: female, OR = 0.68, 95% CI: 0.52-0.88), working hours (OR = 1.11, 95% CI: 1.03-1.20), and sleeping hours (OR = 0.84, 95% CI: 0.75-0.95) were significantly associated with CMP. Participants were categorized into four groups according to working hours (long: ≥ 9 hours/day [long-work], short: < 9 hours/day [short-work]) and sleeping hours (long: ≥ 7 hours/day [long-sleep], short: < 7 hours/day [short-sleep]). Furthermore, logistic regression analysis showed that the CMP OR was 2.02 (95% CI: 1.46-2.78) times higher in 'long-work plus short-sleep workers' and 1.47 (95% CI: 0.94-2.30) times higher in 'long-work plus long-sleep workers' than in 'short-work plus long-sleep workers'. Thus, working hours are associated with CMP frequency, but sleeping sufficiently may prevent CMP in workers even if they work for long hours. In conclusion, adequate instructions on sleeping hours should be provided by occupational health staff, as this may be effective in preventing CMP.

Time pressure and sleep problems due to thoughts about work as risk factors for future sickness absence

Purpose

This study investigated whether time pressure or sleep problems due to thoughts about work are associated with future sickness absence (SA) among women and men employed in different sectors, also when adjusting for confounders including familial factors (genetics and shared environment).

Methods

The study sample included 16,127 twin individuals (52% women), aged 19–47 years who in 2005 participated in an online survey including questions regarding time pressure, sleep, work and health. Register data on SA (> 14 days) were obtained from the National Social Insurance Agency and individuals were followed from date of survey response until 12/31/2013. Associations between time pressure, sleep problems due to thoughts about work and future SA were investigated using logistic regression analyses to assess odds ratios (OR) with 95% confidence intervals (CI).

Results

In total 5723 (35%) individuals had an incident SA spell during follow-up. Sleep problems due to thoughts about work were associated with SA in the fully adjusted model (OR 1.22, CI 1.10–1.36). Stratified by sector, the highest estimate was found for state employees (OR 1.54, CI 1.11–2.13). Familial factors did not seem to influence the associations. We found no statistically significant associations between time pressure and SA. No sex differences were found.

Conclusions

Results indicated that sleep problems due to thoughts about work is a risk factor for future SA. This follows previous research showing that sleep length and sleep disturbances, regardless of reason, are associated with SA. But, experiences of work-related time pressure seem to have no effect on SA.

Impact of working hours on sleep and mental health

Background

The number of hours people are required to work has a pervasive influence on both physical and mental health. Excessive working hours can also negatively affect sleep quality. The impact at work of mental health problems can have serious consequences for individuals' as well as for organizations' productivity.

Aims

To evaluate differences in sleep quality and anxiety and depression symptoms between longer working hours group (LWHG) and regular working hours group (RWHG). To examine factors influencing weekly working hours, sleep quality and anxiety and depressive symptoms.

Methods

Participants were divided into two groups, RWHG and LWHG, based on working hours, with a cut-off of 48 h per week. We used the Hospital Anxiety and Depression Scale (HADS) to assess anxiety and depression symptoms and the Pittsburgh Sleep Quality Index (PSQI) to measure the quality and patterns of sleep.

Results

The response rate was 23%. Among the 429 study participants, those in the LWHG group (n = 256, 53%) had significantly more depressive and anxiety symptoms and worse sleep quality than those in RWHG (n = 223, 47%). Working time was significantly positively correlated with higher corporate position and HADS scores. Moreover, HADS scores were positively correlated with PSQI scores and negatively correlated with age.

Conclusions

This study suggests that longer working hours are associated with poorer mental health status and increasing levels of anxiety and depression symptoms. There was a positive correlation between these symptoms and sleep disturbances.

Neighborhood social capital and sleep duration: a population based cross-sectional study in a rural Japanese town

Background

Studies on social capital and health outcomes have become common, but the relationship between neighborhood social capital and sleep duration by gender is still unclear. We examined the relationship between neighborhood social capital and sleep duration by gender in adults living in a rural community in Japan.

Method

We conducted a cross-sectional survey of 12,321 residents aged ≥20 years in a town in Mie Prefecture in January–March 2013. Self-completed questionnaires were collected from the residents (n = 7782; valid participation rate, 63.2%). We used five items to assess the neighborhood social capital (Cronbach’s α = 0.86). We summed up the scores of each item, and then divided the participants into four groups by quartile of total scores of neighborhood social capital (lowest, low, high, and highest). Sleep duration of < 7 h/day was defined as insufficient sleep duration according to previous studies. To adjust for potential confounders, we performed a multiple log-binominal regression analysis and estimated the prevalence ratios (PRs) and 95% confidence intervals (CIs) for insufficient sleep.

Results

Overall 42% of the men and 45% of the women had insufficient sleep. In the men, the lowest group of neighborhood social capital presented a 22% higher prevalence of insufficient sleep (PR 1.22; 95% CIs 1.08–1.38) compared to the highest group of neighborhood social capital. Similarly the low group of neighborhood social capital and the high group of neighborhood social capital had 20 and 19% higher prevalence of insufficient sleep (PR 1.20; 95% CIs 1.06–1.36; PR 1.19; 95% CIs 1.06–1.34, respectively) compared to the highest group of neighborhood social capital. For women there was no significant association between neighborhood social capital and insufficient sleep after controlling for all potential confounders.

Conclusion

Having lower neighborhood social capital was associated with insufficient sleep among Japanese adults, particularly in the men. This suggests that the context of neighborhood social capital by gender should be considered to promote healthier behaviors with regard to getting enough sleep.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5204-4) contains supplementary material, which is available to authorized users.

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.

The relationship between sleep disturbances and depression in daytime workers: a cross-sectional structured interview survey

The aim of this study was to clarify the relationship between sleep disturbances and depression in daytime workers using a structured interview. A total of 1,184 daytime workers were enrolled. We evaluated difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), and global insomnia scores (ISs) in all participants. As a result, the prevalences of DIS, DMS, and EMA were 16%, 46%, and 22 %, respectively. IS was significantly correlated with depression score. Additionally, although all IS subscales (i.e., DIS, DMS, and EMA) were significantly associated with depression score, the main factor contributing to depression score was DIS. Thus, the present study reveals that sleep disturbances and especially DIS are associated with depression in daytime workers.

Long working hours directly and indirectly (via short sleep duration) induce headache even in healthy white-collar men: cross-sectional and 1-year follow-up analyses

OBJECTIVE

Headache in employees may be linked with both overwork and sleep restriction induced by long working hours. Inter-relationships among working hours, sleep duration and headache were investigated.

METHODS

Cross-sectional analyses for prevalent headache (n = 35,908) and 1-year follow-up analyses for incident headache (n = 19,788) were conducted in apparently healthy white-collar men aged 25-59 years. Headache (yes/no), working hours and sleep duration were based on self-administered questionnaire. After determination of relationships between working hours and sleep duration, logistic regression analysis estimated odds ratio (OR) and 95% confidence interval for prevalent and incident headache according to working hours (35-44, 45-49, 50-59 and ≥60 h/week) and sleep duration (≥7, 6-6.9, 5-5.9 and <5 h/day), and tested linear trends in OR. Additionally, interactive effects of working hours and sleep duration on OR were checked. Covariates in the analyses were age, body mass index, drinking, smoking and exercise.

RESULTS

Prevalent and incident headache was found in 1979 (5.5%) men and 707 (3.6%) men, respectively. Working hours were inversely associated with sleep duration. OR for prevalent and incident headache rose with increasing working hours and with reducing sleep duration, regardless of influences of the covariates. Working hours and sleep duration had no interactive effects on OR for prevalent or incident headache.

CONCLUSIONS

The results indicate that long working hours directly and indirectly (via short sleep duration) induce headache even in apparently healthy white-collar men. Headache in employees may be useful for early detection of adverse health effects by long working hours.

Work, sleep, and cholesterol levels of U.S. long-haul truck drivers

Long-haul truck drivers in the United States experience elevated cardiovascular health risks, possibly due to hypercholesterolemia. The current study has two objectives: 1) to generate a cholesterol profile for U.S. long-haul truck drivers; and 2) to determine the influence of work organization characteristics and sleep quality and duration on cholesterol levels of long-haul truck drivers. Survey and biometric data were collected from 262 long-haul truck drivers. Descriptive analyses were performed for demographic, work organization, sleep, and cholesterol measures. Linear regression and ordinal logistic regression analyses were conducted to examine for possible predictive relationships between demographic, work organization, and sleep variables, and cholesterol outcomes. The majority (66.4%) of drivers had a low HDL (<40 mg/dL), and nearly 42% of drivers had a high-risk total cholesterol to HDL cholesterol ratio. Sleep quality was associated with HDL, LDL, and total cholesterol, and daily work hours were associated with LDL cholesterol. Workday sleep duration was associated with non-HDL cholesterol, and driving experience and sleep quality were associated with cholesterol ratio. Long-haul truck drivers have a high risk cholesterol profile, and sleep quality and work organization factors may induce these cholesterol outcomes. Targeted worksite health promotion programs are needed to curb these atherosclerotic risks.

Work environment, overtime and sleep among offshore personnel

Personnel working on North Sea oil/gas installations are exposed to remote and potentially hazardous environments, and to extended work schedules (typically, 14×12h shifts). Moreover, overtime (additional to the standard 84-h week) is not uncommon among offshore personnel. Evidence from onshore research suggests that long work hours and adverse environmental characteristics are associated with sleep impairments, and consequently with health and safety risks, including accidents and injuries. However, little is known about the extent to which long hours and a demanding work environment combine synergistically in relation to sleep. The present study sought to address this issue, using survey data collected from offshore day-shift personnel (N=551). The multivariate analysis examined the additive and interactive effects of overtime and measures of the psychosocial/physical work environment (job demands, job control, supervisor support, and physical stressors) as predictors of sleep outcomes during offshore work weeks. Control variables, including age and sleep during leave weeks, were also included in the analysis model. Sleep duration and quality were significantly impaired among those who worked overtime (54% of the participants) relative to those who worked only 12-h shifts. A linear relationship was found between long overtime hours and short sleep duration; personnel who worked >33h/week overtime reported <6h/day sleep. Significant interactions were also found; sleep duration was negatively related to job demands, and positively related to supervisor support, only among personnel who worked overtime. Poor sleep quality was predicted by the additive effects of overtime, low support and an adverse physical environment. These findings highlight the need to further examine the potential health and safety consequences of impaired sleep associated with high overtime rates offshore, and to identify the extent to which adverse effects of overtime can be mitigated by favourable physical and psychosocial work environment characteristics.