著者
Keisuke Kuwahara Teppei Imai Toshiaki Miyamoto Takeshi Kochi Masafumi Eguchi Akiko Nishihara Tohru Nakagawa Shuichiro Yamamoto Toru Honda Isamu Kabe Tetsuya Mizoue Seitaro Dohi
出版者
Japan Epidemiological Association
雑誌
Journal of Epidemiology (ISSN:09175040)
巻号頁・発行日
pp.JE20170024, (Released:2018-02-03)
参考文献数
15

Background: Evidence linking working hours and the risk of type 2 diabetes mellitus (T2DM) is limited and inconsistent in Asian populations. No study has addressed the combined association of long working hours and sleep deprivation on T2DM risk. We investigated the association of baseline overtime work with T2DM risk and assessed whether sleep duration modified the effect among Japanese.Methods: Participants were Japanese employees (28,489 men and 4,561 women) aged 30–64 years who reported overtime hours and had no history of diabetes at baseline (mostly in 2008). They were followed up until March 2014. New-onset T2DM was identified using subsequent checkup data, including measurement of fasting/random plasma glucose, glycated hemoglobin, and self-report of medical treatment. Hazard ratios (HRs) of T2DM were estimated using Cox regression analysis. The combined association of sleep duration and working hours was examined in a subgroup of workers (n = 27,590).Results: During a mean follow-up period of 4.5 years, 1,975 adults developed T2DM. Overtime work was not materially associated with T2DM risk. In subgroup analysis, however, long working hours combined with insufficient sleep were associated with a significantly higher risk of T2DM (HR 1.42; 95% CI, 1.11–1.83), whereas long working hours with sufficient sleep were not (HR 0.99; 95% CI, 0.88–1.11) compared with the reference (<45 hours of overtime with sufficient sleep).Conclusions: Sleep duration modified the association of overtime work with the risk of developing T2DM. Further investigations to elucidate the long-term effect of long working hours on glucose metabolism are warranted.
著者
Miwa Yamaguchi Masafumi Eguchi Shamima Akter Takeshi Kochi Huanhuan Hu Ikuko Kashino Keisuke Kuwahara Isamu Kabe Tetsuya Mizoue
出版者
Japan Society for Occupational Health
雑誌
Journal of Occupational Health (ISSN:13419145)
巻号頁・発行日
pp.2017-0298-OA, (Released:2018-09-27)

Objective: To investigate associations of work-related stressors and their changes over time with the risk of developing metabolic syndrome (MetS) among Japanese manufacturing workers.Methods: Participants were 1,040 employees aged 19 to 68 years who were free from MetS at baseline and completed the three year-interval follow-up survey. MetS was defined according to the Joint Interim Statement. Work-related stressors (job strain, job demands, job control, and worksite social support) were assessed based on the Job Content Questionnaire and were split into two categories (low and high) by the median value at each survey. Multivariable logistic regression was performed to investigate the associations of baseline work-related stressors and their changes over time with the incidence of MetS.Results: Three years later, 61 workers developed MetS. Higher job demands at baseline were significantly associated with a lower risk of MetS (adjusted odds ratio 0.46, 95% confidential interval: 0.24, 0.89). In the analyses of the changes in stressors over time, those whose job demands changed from low to high showed significantly higher risk of MetS (adjusted odds ratio 3.27, 95% confidential interval: 1.46, 7.34), compared with those who reported low job demands in both surveys.Conclusions: Results suggest that an increase in job demands over time, but not higher job demands at baseline, is associated with increased risk of MetS.