Are changes in objective working hour characteristics associated with changes in work-life conflict among hospital employees working shifts? A 7-year follow-up

ObjectiveTo investigate whether changes in objective working hour characteristics are associated with parallel changes in work-life conflict (WLC) among hospital employees.MethodsSurvey responses from three waves of the Finnish Public Sector study (2008, 2012 and 2015) were combined with payroll data from 91 days preceding the surveys (n=2 482, 93% women). Time-dependent fixed effects regression models adjusted for marital status, number of children and stressfulness of the life situation were used to investigate whether changes in working hour characteristics were associated with parallel change in WLC. The working hour characteristics were dichotomised with cut-points in less than or greater than 10%or less than or greater than25%occurrence) and WLC to frequent versus seldom/none.ResultsChange in proportion of evening and night shifts and weekend work was significantly associated with parallel change in WLC (adjusted OR 2.19, 95%CI 1.62 to 2.96; OR 1.71, 95%CI 1.21 to 2.44; OR 1.63, 95%CI 1.194 to 2.22, respectively). Similarly, increase or decrease in proportion of quick returns (adjusted OR 1.45, 95%CI 1.10 to 1.89) and long work weeks (adjusted OR 1.26, 95%CI 1.04 to 1.52) was associated with parallel increase or decrease in WLC. Single days off and very long work weeks showed no association with WLC.ConclusionsChanges in unsocial working hour characteristics, especially in connection with evening shifts, are consistently associated with parallel changes in WLC.Peer reviewe

Cognitive behavioural therapy interventions for insomnia among shift workers : RCT in an occupational health setting

Introduction The aim of the study was to compare the effectiveness of cognitive behavioural therapy interventions for insomnia (CBT-I) to that of a sleep hygiene intervention in a randomized controlled design among shift workers. We also studied whether the features of shift work disorder (SWD) affected the results. Methods A total of 83 shift workers with insomnia disorder were partially randomized into a group-based CBT-I, self-help CBT-I, or sleep hygiene control intervention. The outcomes were assessed before and after the interventions and at 6-month follow-up using questionnaires, a sleep diary, and actigraphy. Results Perceived severity of insomnia, sleep-related dysfunctional beliefs, burnout symptoms, restedness, recovery after a shift, and actigraphy-based total sleep time improved after the interventions, but we found no significant differences between the interventions. Mood symptoms improved only among the group-based CBT-I intervention participants. Non-SWD participants had more mental diseases and symptoms, used more sleep-promoting medication, and had pronounced insomnia severity and more dysfunctional beliefs than those with SWD. After the interventions, non-SWD participants showed more prominent improvements than those with SWD. Conclusions Our results showed no significant differences between the sleep improvements of the shift workers in the CBT-I interventions and of those in the sleep hygiene control intervention. Alleviation of mood symptoms seemed to be the main added value of the group-based CBT-I intervention compared to the control intervention. The clinical condition of the non-SWD participants was more severe and these participants benefitted more from the interventions than the SWD participants did.Peer reviewe

Associations between shift work and use of prescribed medications for the treatment of hypertension, diabetes, and dyslipidemia : a prospective cohort study

Objective This study examined the associations between shift work and use of antihypertensive, lipid-lowering, and antidiabetic medications. Methods Survey data from two cohorts of Finnish men (N=11998) and women (N=49 944) working in multiple occupations where shift work was used were linked to national Drug Prescription Register data, with up to 11 years of follow-up. In each cohort, age-stratified Cox proportional hazard regression models were computed to examine any incident use of prescription medication for each of the three medical conditions, separately comparing each of two groups of rotating shift workers (those whose schedules included night shifts. and those whose schedules did not include night shifts) with day workers who worked in a similar range of occupations. Results In the larger cohort, among participants aged 40-49 at baseline, shift work without night shifts was associated with increased use of type-2 diabetes medication after adjustments for sex, occupational status, marital status, alcohol consumption, smoking, and physical activity [hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.01-1.62], while shift work with night shifts was associated with increased use of dyslipidemia medication after adjustments (HR 1.33, 95% CI 1.12-1.57). There were no such associations among younger and older shift workers. Also in the larger cohort, among those aged Conclusions There was mixed evidence regarding the use of medications for cardiovascular risk factors by shift workers. Selection effects may have affected the associations.Peer reviewe

Working hour patterns and risk of occupational accidents : an optimal matching analysis in a hospital employee cohort

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Association of Job Strain With Cortisol and Alpha-Amylase Among Shift-Working Health Care Professionals in Laboratory and Field

Although the prevalence of work-related stress has increased, knowledge on the contributions of that stress to long-term adverse health effects is still lacking. Stress biomarkers can reveal early signs of negative health effects, but no previous studies have measured both acute stress reactions and long-term exposure to job strain using both salivary cortisol and -amylase (AA). The present study examines the association between job strain and these biomarkers among shift-working female health care professionals in the laboratory and the field. The 95 participants were recruited from hospital wards categorized in either the top (high job strain [HJS] group, n = 42) or the bottom quartile of job strain (low job strain [LJS] group, n = 53), as rated by survey responses. Participants' self-perceived job strain was at least as high or low as the ward's average estimation. Saliva samples were collected during the Trier Social Stress Test (TSST), preselected morning and night shifts, and a day off. There was a larger increase in the cortisol concentration of participants in the HJS than in the LJS group (2.27- vs. 1.48-fold, respectively, nonsignificant) during the TSST. Participants in the HJS group also had higher salivary AA levels 30 min after awakening on the morning-shift day than those in the LJS group (p = .02), whereas the salivary cortisol awakening response on the day off was higher in the LJS group (p = .05, education as a covariate). The remaining stress-biomarker results did not differ significantly between groups. These data suggest that HJS in shift-working health care professionals is weakly associated with changes in stress biomarkers.Peer reviewe

Association of changes in work shifts and shift intensity with change in fatigue and disturbed sleep : a within-subject study

Objectives The aim of this study was to examine whether changes in work shifts and shift intensity are related to changes in difficulties to fall asleep, fatigue, and sleep length. Methods Questionnaire responses of hospital employees (N=7727, 93% women) in 2008, 2012, 2014 and 2015 were linked to daily-based records of working hours during three months preceding each survey. We used conditional logistic regression and longitudinal fixed-effects analyses to investigate odds ratios (OR) and 95% confidence intervals (CI) for each 25% within-individual change in the proportion of working hour characteristics in relation to changes in fatigue, difficulties to fall asleep, and 24-hour sleep length. Results Change in night but not in morning or evening shifts was associated with parallel changes in odds for longer sleep length (OR 1.45, 95% CI 1.28-1.64) and fatigue during free days (OR 1.38, 95% CI 1.16-1.64). Similarly, short shift intervals and having >2 but not >4 consecutive night shifts were associated with increased odds of fatigue during work and difficulties to fall asleep (OR 1.42, 95% CI 1.19-1.72 and OR 1.10, 95% CI 1.05-1.19, respectively). Among workers aged >= 50 years, the associations were the strongest between night shifts and longer sleep (OR 2.24,95% CI 1.52-3.81) and between higher proportion of short shift intervals and fatigue during free days (OR 1.68, 95% CI 1.10-2.54). Conclusions Among shift workers with fatigue or sleep problems, decreasing the proportion of night shifts and quick returns and giving preference to quickly forward-rotating shift systems may reduce fatigue.Peer reviewe

Prolonged Sleep Restriction Affects Glucose Metabolism in Healthy Young Men

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Common Genetic Variation Near Melatonin Receptor 1A Gene Linked to Job-Related Exhaustion in Shift Workers

Study Objectives: Tolerance to shift work varies; only some shift workers suffer from disturbed sleep, fatigue, and job-related exhaustion. Our aim was to explore molecular genetic risk factors for intolerance to shift work. Methods: We assessed intolerance to shift work with job-related exhaustion symptoms in shift workers using the emotional exhaustion subscale of the Maslach Burnout Inventory-General Survey, and carried out a genome-wide association study (GWAS) using Illumina's Human610-Quad BeadChip (n = 176). The most significant findings were further studied in three groups of Finnish shift workers (n = 577). We assessed methylation in blood cells with the Illumina HumanMethylation450K BeadChip, and examined gene expression levels in the publicly available eGWAS Mayo data. Results: The second strongest signal identified in the GWAS (p = 2.3 x 10E-6) was replicated in two of the replication studies with p Conclusions: These findings suggest that a variant near MTNR1A may be associated with job-related exhaustion in shift workers. The risk variant may exert its effect via epigenetic mechanisms, potentially leading to reduced melatonin signaling in the brain. These results could indicate a link between melatonin signaling, a key circadian regulatory mechanism, and tolerance to shift work.Peer reviewe

Environmental Stress Affects DNA Methylation of a CpG Rich Promoter Region of Serotonin Transporter Gene in a Nurse Cohort

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Prolonged sleep restriction induces changes in pathways involved in cholesterol metabolism and inflammatory responses

Sleep loss and insufficient sleep are risk factors for cardiometabolic diseases, but data on how insufficient sleep contributes to these diseases are scarce. These questions were addressed using two approaches: an experimental, partial sleep restriction study (14 cases and 7 control subjects) with objective verification of sleep amount, and two independent epidemiological cohorts (altogether 2739 individuals) with questions of sleep insufficiency. In both approaches, blood transcriptome and serum metabolome were analysed. Sleep loss decreased the expression of genes encoding cholesterol transporters and increased expression in pathways involved in inflammatory responses in both paradigms. Metabolomic analyses revealed lower circulating large HDL in the population cohorts among subjects reporting insufficient sleep, while circulating LDL decreased in the experimental sleep restriction study. These findings suggest that prolonged sleep deprivation modifies inflammatory and cholesterol pathways at the level of gene expression and serum lipoproteins, inducing changes toward potentially higher risk for cardiometabolic diseases.Peer reviewe