保坂 唯仁

BACKGROUND: Work-related stress is associated with cardiovascular disease (CVD), yet the contributions of specific work-related stressors, support and satisfaction to CVD incidence are not fully understood. Clarifying whether lifestyle behaviors and physiological factors mediate associations between stressors and CVD is essential for targeted prevention. METHODS: In this prospective cohort study, a cohort of 4,820 Japanese workers (3,876 men and 944 women) aged 35-65 years was followed up for CVD incidence from 2007 to 2022. Work-related stressors (e.g., quantitative job overload), support (e.g., supervisor support) and satisfaction (e.g., family life satisfaction) were assessed using the 57-item Brief Job Stress Questionnaire. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD risk. Mediation analysis evaluated the role of lifestyle behaviors (e.g., smoking, alcohol consumption) and physiological factors (e.g., systolic blood pressure, obesity) in the association between stressors and CVD incidence. RESULTS: Quantitative job overload, low supervisor support, and low family life satisfaction were independently associated with increased CVD incidence (HRs ranging from 1.69 to 2.33). A part (24.9%) of the association of quantitative job overload with CVD was significantly mediated by obesity (p=0.007). CONCLUSION: Quantitative job overload, lack of supervisor support, and low family life satisfaction were significant predictors of CVD among Japanese civil servants. These findings suggest that both reducing excessive workload and strengthening support systems inside and outside the workplace may be important for cardiovascular disease prevention among Japanese civil servants.

PURPOSE: This study aimed to (1) identify distinct multidimensional fatigue profiles among employed cancer survivors, (2) examine associations between workplace factors and these profiles, and (3) assess how these profiles are associated with occupational outcomes. METHODS: Seventy-two employed cancer survivors aged 27 to 64 years (median 9.4 years since diagnosis) from a local government in Japan completed questionnaires in 2023 assessing cancer-related fatigue (Cancer Fatigue Scale), workplace factors (job demands, job control, workplace support), and occupational outcomes (work engagement, presenteeism, cognitive function at work, and quality of life). Fatigue profiles were identified using hierarchical cluster analysis. Associations between workplace factors and profiles were examined using multinomial logistic regression. Occupational outcome differences among profiles were examined using linear regression. RESULTS: Three profiles were identified: Low Global Fatigue (n = 12), Dominant Mental Fatigue (n = 36), and High Global Fatigue (n = 24). Workplace support-particularly supervisor understanding, colleague understanding, and schedule flexibility-was associated with approximately 75% lower odds of belonging to the High Global Fatigue group. Job demands and job control showed no associations. The High Global Fatigue group reported lower work engagement, higher presenteeism, reduced cognitive function at work, and poorer quality of life compared to the other groups. CONCLUSIONS: Three multidimensional fatigue profiles were identified among employed cancer survivors. Workplace support factors were more strongly associated with fatigue profiles than job characteristics. These profiles were associated with occupational outcomes. IMPLICATION FOR CANCER SURVIVORS: These distinct fatigue profiles can guide personalized workplace interventions to optimize support for employed cancer survivors.

Abstract Objectives: Various factors influence urinary hippuric acid concentrations; however, the role of climatic factors on such concentrations has not been thoroughly investigated. Methods: This study examined the correlation between urinary hippuric acid concentrations and climatic factors. Data were obtained from health examinations of 2236 employees at a large manufacturing company who used organic solvents over a 3-year period. Each participant underwent a health examination for organic solvent use during both the summer (June to August) and winter (December to February). Urinary hippuric acid concentrations were log-transformed, and a linear mixed-effects model was applied to assess their association with average temperature, relative humidity, and atmospheric pressure recorded in Nagoya City, Japan. Results: In a multivariate linear mixed-effects model including all meteorological variables, average temperature showed a significant positive association with log-transformed urinary hippuric acid concentrations (estimate = 0.013; 95% CI: 0.007-0.020; P < .001). This corresponds to an estimated 1.3% increase in urinary hippuric acid concentrations per 1°C rise in temperature. In contrast, neither average atmospheric pressure nor relative humidity showed a statistically significant association (P = .981 and P = .817, respectively). Among the confounding variables, smoking was significantly positively associated with concentration (P = .001), whereas alcohol consumption showed a significant negative association (P = .031). Conclusions: Urinary hippuric acid concentrations exhibited seasonal variation among workers at a large manufacturing company, with elevated levels observed during the summer. These findings underscore the importance of considering climatic factors when interpreting urinary metabolic biomarkers.

ABSTRACT Objective To examine the characteristics associated with happiness in Japanese individuals with schizophrenia. Methods A self‐reported online survey was conducted in 2022 among individuals aged 20–75 years, including 223 and 1776 individuals with and without schizophrenia, respectively. We used a modified Poisson regression to assess the factors associated with happiness by calculating the age‐ and sex‐adjusted prevalence ratios (PRs). We examined within‐schizophrenia group differences by age and sex strata, and compared these stratified PRs between groups with and without schizophrenia. Results Among participants with schizophrenia, happiness was significantly associated with self‐rated health status (PR = 1.75), Ikigai (PR = 5.02), depressive symptoms (PR = 0.43), perceived stress (PR = 0.52), cognitive social capital (PR = 2.07), structural social capital (PR = 1.70), social support (PR = 2.40), close friends (PR = 1.88), close relatives (PR = 2.34), and a cohabiting partner (PR = 1.57). Within the schizophrenia group, sex differences were significant for cognitive social capital (men: PR = 3.45; women: PR = 1.43) and cohabiting partners (men: PR = 2.26; women: PR = 1.25), whereas no significant age differences were found. Factors demonstrating a stronger association in participants with schizophrenia than in those without schizophrenia included: Ikigai (with, PR = 5.02; without, PR = 2.91), cognitive social capital (with, PR = 2.07; without, PR = 1.49), and structural social capital (with, PR = 1.70; without, PR = 1.24). Conclusion Happiness in individuals with schizophrenia is associated with physical, mental, and social factors, with social factors exhibiting sex‐related differences.