To maximize their fitness, parents are assumed to allocate their resources optimally between number and size of offspring. Although this fundamental life-history trade-off has been subject to long ...standing interest, its genetic basis, especially in wild mammals, still remains unresolved. One important reason for this problem is that a large multigenerational pedigree is required to conduct a reliable analysis of this trade-off.
We used the REML-animal model to estimate genetic parameters for litter size and individual birth size for a common Palearctic small mammal, the bank vole (Myodes glareolus). Even though a phenotypic trade-off between offspring number and size was evident, it was not explained by a genetic trade-off, but rather by negative correlations in permanent and temporary environmental effects. In fact, even positive genetic correlations were estimated between direct genetic effects for offspring number and size indicating that genetic variation in these two traits is not necessarily antagonistic in mammals.
Our results have notable implications for the study of the life-history trade-off between offspring number and size in mammals. The estimated genetic correlations suggest that evolution of offspring number and size in polytocous mammals is not constrained by the trade-off caused by antagonistic selection responses per se, but rather by the opposing correlative selection responses in direct and maternal genetic effects for birth size.
Objectives This study aimed to examine the contribution of shift work, work time control (WTC) and informal caregiving, separately and in combination, to sleep disturbances in ageing employees. ...Methods Survey data were obtained from two prospective cohort studies with repeated measurements of working conditions, informal caregiving, and sleep disturbances. We used fixed-effect conditional logistic regression analysis to examine whether within-individual changes in shift work, WTC and informal caregiving were associated with changes in sleep. Secondary analyses included between-individuals comparison using standard logistic regression models. Results from the two cohorts were pooled using meta-analysis. Results Low WTC and informal caregiving were associated with sleep disturbances in within-individual analyses odds ratios (OR) ranging between 1.13 (95% confidence interval 1.01-1.27) and 1.48 (95% CI 1.29-1.68) and in between-individuals analyses OR 1.14 (95% CI 1.03-1.26) to 1.33 (1.19-1.49). Shift work alone was not associated with sleep disturbances, but accumulated exposure to shift work, low WTC and informal caregiving was associated with higher risk of sleep disturbances (OR range 1.21-1.76). For some of the sleep outcomes, informal caregiving was related to a higher risk of sleep disturbances when WTC was low and a lower risk when WTC was high. Conclusions Informal caregiving and low WTC are associated with risk of sleep disturbances among ageing employees. The findings also suggest that low WTC in combination with informal caregiving may increase the risk of sleep disturbances whereas high WTC may alleviate the adverse impact of informal caregiving on sleep.
Depression is a major cause of disability in working populations and the reduction of socioeconomic inequalities in disability is an important public health challenge. We examined work disability due ...to depression with four indicators of socioeconomic status.
A prospective cohort study of 125 355 Finnish public sector employees was linked to national register data on work disability (>9 days) due to depressive disorders (International Classification of Diseases, codes F32-F34) from January 2005 to December 2011. Primary outcomes were the onset of work disability due to depressive disorders and, among those with such disability, return to work after and recurrent episodes of work disability due to depression.
We found a consistent inverse socioeconomic gradient in work disability due to depression. Lower occupational position, lower educational level, smaller residence size, and rented (vs. owner-occupied) residence were all associated with an increased risk of work disability. Return to work was slower for employees with basic education (cumulative odds ratio = 1.21, 95% CI: 1.05-1.39) compared to those with higher education. Recurrent work disability episodes due to depression were less common among upper-grade non-manual workers (the highest occupational group) than among lower-grade non-manual (hazard ratio = 1.16, 95% CI: 1.07-1.25) and manual (hazard ratio = 1.14, 95% CI: 1.02-1.26) workers.
These data from Finnish public sector employees show persistent socioeconomic inequalities in work disability due to depression from 2005 to 2011 in terms of onset, recovery and recurrence.
A growing number of studies have sought to examine the health associations of workplace social capital; however, evidence of associations with overweight is sparse. We examined the association ...between individual perceptions of workplace social capital and overweight among Japanese male and female employees.
We conducted a cross-sectional survey among full-time employees at a company in Osaka prefecture in February 2012. We used an 8-item measure to assess overall and sub-dimensions of workplace social capital, divided into tertiles. Of 1050 employees, 849 responded, and 750 (624 men and 126 women) could be linked to annual health check-up data in the analysis. Binomial logistic regression models were used to calculate odds ratios and 95% confidence intervals for overweight (body mass index: ≥ 25 kg/m(2), calculated from measured weight and height) separately for men and women. The prevalence of overweight was 24.5% among men and 14.3% among women. Among men, low levels of bonding and linking social capital in the workplace were associated with a nearly 2-fold risk of overweight compared to high corresponding dimensions of social capital when adjusted for age, sleep hours, physiological distress, and lifestyle. In contrast, among women we found lower overall and linking social capital to be associated with lower odds for overweight even after covariate adjustment. Subsequently, we used multinomial logistic regression analyses to assess the relationships between a 1 standard deviation (SD) decrease in mean social capital and odds of underweight/overweight relative to normal weight. Among men, a 1-SD decrease in overall, bonding, and linking social capital was significantly associated with higher odds of overweight, but not with underweight. Among women, no significant associations were found for either overweight or underweight.
We found opposite gender relationships between perceived low linking workplace social capital and overweight among Japanese employees.
Organizational justice perceptions have been suggested to be associated with symptoms of mental health but the nature of the association is unknown due to reporting bias (measurement error related to ...response style and reversed causality). In this study, we used prospective design and long-term (>9 days) sickness absence with psychiatric diagnosis as the outcome measure. Participants were 21 221 Finnish public sector employees (the participation rate at baseline in 2000–2002 68%), who responded to repeated surveys of procedural and interactional justice in 2000–2004 along with register data on sickness absence with a diagnosis of depression or anxiety disorders (822 cases). Results from logistic regression analyses showed that a one-unit increase in self-reported and work-unit level co-worker assessed interactional justice was associated with a 25–32% lower odds of sickness absence due to anxiety disorders. These associations were robust to adjustments for a variety of potential individual-level confounders including chronic disease (adjusted OR for self-reported interactional justice 0.77, 95% CI 0.65–0.91) and were replicated using co-worker assessed justice. Only weak evidence of reversed causality was found. The results suggest that low organizational justice is a risk factor for sickness absence due to anxiety disorders.
•In studying mental health risks, relying only on self-reported measures is problematic.•Using independent mental health outcomes and prospective designs are important.•We showed that organizational justice predicted less sickness absences due to anxiety disorders.•The associations were replicated using work-unit level measures of organizational justice.•Only limited support was found for reversed causality.
Background Despite evidence showing anxiety to be a negative emotion that can be accompanied by various psychological and somatic complaints, previous studies have rarely considered these two ...components of anxiety separately in relation to coronary heart disease (CHD) events. This study aims to examine the extent to which the psychological and somatic components of anxiety are predictive of CHD. Methods This is a prospective population-based cohort study of 24,128 participants (9830 men, 14,298 women) aged 20 to 54 years. Psychological and somatic symptoms were assessed at study baseline in 1998. Fatal and nonfatal CHD events during the following 7 years were documented from data on hospitalizations from the National Hospital Discharge Register and mortality records from the Statistics Finland Register. Results In men, unadjusted hazard ratios for CHD per one unit increase in mean score were 1.50 (95% confidence interval CI, 1.21–1.87) for somatic symptoms and 1.04 (95% CI, .85–1.29) for psychological symptoms. After serial adjustment for sociodemographic characteristics, biobehavioral risk factors, and clinically significant symptoms of depression, these associations were completely attenuated. In women, the corresponding unadjusted hazard ratios were 2.25 (95% CI, 1.66–3.06) and 1.55 (95% CI, 1.12–2.13), respectively. The corresponding fully adjusted hazard ratios were 1.47 (95% CI, 1.04–2.06) and 1.24 (95% CI, .91–1.70). Conclusions Somatic symptoms of anxiety were robustly associated with an increased risk of CHD in women. This finding lends support to the physiological pathway for the association between psychological factors, anxiety in particular, and CHD.
To examine whether workplace social capital improved after implementing a workplace social capital intervention in community health centers in China.
This study was conducted in 20 community health ...centers of similar size in Jinan of China during 2012-2013. Using the stratified site randomization, 10 centers were randomized into the intervention group; one center was excluded due to leadership change in final analyses. The baseline survey including 447 staff (response rate: 93.1%) was conducted in 2012, and followed by a six-month workplace social capital intervention, including team building courses for directors of community health centers, voluntarily public services, group psychological consultation, and outdoor training. The follow-up survey in July 2013 was responded to by 390 staff members (response rate: 86.9%). Workplace social capital was assessed with the translated and culturally adapted scale, divided into vertical and horizontal dimensions. The facility-level intervention effects were based on all baseline (n = 427) and follow-up (n = 377) respondents, except for Weibei respondents. We conducted a bivariate Difference-in-Difference analysis to estimate the facility-level intervention effects.
No statistically significant intervention effects were observed at the center level; the intervention increased the facility-level workplace social capital, and its horizontal and vertical dimensions by 1.0 (p = 0.24), 0.4 (p = 0.46) and 0.8 (p = 0.16), respectively.
The comprehensive intervention seemed to slightly improve workplace social capital in community health centers of urban China at the center level. High attrition rate limits any causal interpretation of the results. Further studies are warranted to test these findings.
ObjectivesObservational studies suggest that high job strain is a risk factor for retirement on health grounds, but few studies have analysed specific diagnoses. We examined job strain's association ...with all-cause and cause-specific disability pensions.MethodsSurvey responses to questions about job strain from 48 598 (response rate, 68%) public sector employees in Finland from 2000 to 2002 were used to determine work unit- and occupation-based scores. These job strain scores were assigned to all the 69 842 employees in the same work units or occupations. All participants were linked to the disability pension register of the Finnish Centre of Pensions with no loss to follow-up. Cox proportional hazard models were used to calculate HRs and their 95% CIs for disability pensions adjusted by demographic, work unit characteristics and baseline health in analyses stratified by sex and socioeconomic position.ResultsDuring a mean follow-up of 4.6 years, 2572 participants (4%) were granted a disability pension. A one-unit increase in job strain was associated with a 1.3- to 2.4-fold risk of requiring a disability pension due to musculoskeletal diseases in men, women and manual workers, depending on the measure of job strain (work unit or occupation based). The risk of disability pension due to cardiovascular diseases was increased in men with high job strain but not in women nor in any socioeconomic group. No consistent pattern was found for disability pension due to depression.ConclusionHigh job strain is a risk factor for disability pension due to musculoskeletal diseases.
Objectives To examine whether exposure to workplace stressors predicts changes in physical activity and the risk of insufficient physical activity. Methods Prospective data from the Finnish Public ...Sector Study. Repeated exposure to low job control, high job demands, low effort, low rewards and compositions of these (job strain and effort–reward imbalance) were assessed at Time 1 (2000–2002) and Time 2 (2004). Insufficient physical activity (<14 metabolic equivalent task hours per week) was measured at Time 1 and Time 3 (2008). The effect of change in workplace stressors on change in physical activity was examined using fixed-effects (within-subject) logistic regression models (N=6665). In addition, logistic regression analysis was applied to examine the associations between repeated exposure to workplace stressors and insufficient physical activity (N=13 976). In these analyses, coworker assessed workplace stressor scores were used in addition to individual level scores. Results The proportion of participants with insufficient physical activity was 24% at baseline and 26% at follow-up. 19% of the participants who were sufficiently active at baseline became insufficiently active at follow-up. In the fixed-effect analysis, an increase in workplace stress was weakly related to an increase in physical inactivity within an individual. In between-subjects analysis, employees with repeated exposure to low job control and low rewards were more likely to be insufficiently active at follow-up than those with no reports of these stressors; fully adjusted ORs ranged from 1.11 (95% CI 1.00 to 1.24) to 1.21 (95% CI 1.05 to 1.39). Conclusions Workplace stress is associated with a slightly increased risk of physical inactivity.
Objectives Work-related stress has been linked to increased risk of disability pensioning, but the association between perceived justice of managerial behavior and decision-making processes at the ...workplace (ie, organizational justice) and risk of disability pensioning remains unknown. We examined the associations of organizational justice and its relational and procedural components with all-cause and diagnosis-specific disability pensions with repeated measures of justice. Methods Data from 24 895 employees responding to repeated surveys on organizational justice in 2000-2002 and 2004 were linked to the records of a national register for disability pensions from 2005-2011. Associations of long-term organizational justice (average score from two surveys) with disability pensions were studied with Cox proportional hazard regression adjusted for demographics, socioeconomic status, baseline health and health risk behavior, stratified by sex. Results During a mean follow-up of 6.4 years, 1658 (7%) employees were granted disability pension (282 due to depression; 816 due to musculoskeletal diseases). Higher organizational justice was associated with a lower risk of disability pensioning hazard ratio (HR) per one-unit increase in 5-point justice scale 0.87 (95% CI 0.81-0.94). For disability pension due to depression and musculoskeletal diseases, the corresponding HR were 0.77 (95% CI 0.65-0.91) and 0.87 (95% CI 0.79-0.97), respectively. Adjustment for job strain and effort-reward imbalance attenuated the HR by 20-80%. Conclusions Supervisors' fair treatment of employees and fair decision-making in the organizations are associated with a decreased risk of disability pensioning from all-causes, depression and musculoskeletal diseases. These associations may be attributable to a wider range of favorable work characteristics.
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