Department of Epidemiology and Public Health, Kanazawa Medical University, Uchinada, Japan.
Am J Hypertens. 2012 Sep;25(9):979-85. doi: 10.1038/ajh.2012.37. Epub 2012 Apr 12.
Epidemiological studies have observed conflicting patterns as to whether overtime work increases blood pressure (BP), probably as a consequence of methodological issues.
We conducted a prospective cohort study to investigate the relationship between overtime work hours and 1-year changes in BP in 1,235 normotensive Japanese male workers who carried out a variety of jobs in a manufacturing factory. Casual BP measurements were repeated at annual health examinations in 2004-2005, using an automatic manometer. An analysis of covariance that incorporated potential confounding factors including baseline age, body mass index (BMI), and lifestyle factors was used to calculate and compare the means of the 1-year change in systolic (SBP) and diastolic BP (DBP). The participants were grouped according to their average monthly overtime work hours obtained from timecard data between April and September 2004.
The multivariate-adjusted mean for 1-year change in DBP in 611 male assembly-line workers was 1.5 mm Hg (95% confidence interval (CI) 0.8-2.2) for <40.0 h/month, 2.3 mm Hg (95% CI 1.3-3.2) for 40.0-79.9 h/month, and 5.3 mm Hg (95% CI 2.7-7.9) for ≥ 80.0 h/month (P for heterogeneity = 0.02). A broadly similar pattern was observed for SBP. In contrast, there was no significant difference in means 1-year change for both SBP and DBP in 315 clerks and 309 engineers/special technicians, grouped according to overtime work hours.
Extensive overtime work was associated with increased BP in normotensive male assembly-line workers, but not in clerks and engineers/special technicians.
流行病学研究观察到，超时工作与血压升高之间的关系存在矛盾模式，这可能是由于方法学问题所致。
我们进行了一项前瞻性队列研究，以调查在从事制造业各种工作的 1235 名血压正常的日本男性工人中，超时工作时间与 1 年内血压变化之间的关系。在 2004 年至 2005 年的年度健康检查中，使用自动血压计重复进行偶测血压测量。采用协方差分析，纳入了包括基线年龄、体重指数（BMI）和生活方式因素在内的潜在混杂因素，以计算和比较收缩压（SBP）和舒张压（DBP）1 年变化的平均值。根据 2004 年 4 月至 9 月期间的考勤数据得出的平均每月超时工作时间，将参与者分为不同的组。
在 611 名装配线工人中，多变量调整后的 1 年 DBP 变化平均值为：<40.0 h/月时为 1.5 mmHg（95%置信区间（CI）为 0.8-2.2）；40.0-79.9 h/月时为 2.3 mmHg（95% CI 为 1.3-3.2）；≥80.0 h/月时为 5.3 mmHg（95% CI 为 2.7-7.9）（异质性 P = 0.02）。SBP 也观察到了类似的模式。相比之下，根据超时工作时间分组的 315 名文员和 309 名工程师/专业技术人员中，SBP 和 DBP 的 1 年变化平均值没有显著差异。
大量超时工作与血压正常的装配线工人的血压升高有关，但与文员和工程师/专业技术人员无关。
