Cancer Epidemiology Unit, University of Oxford, Oxford OX3 7L, United Kingdom.
Scand J Work Environ Health. 2012 Nov;38(6):590-9. doi: 10.5271/sjweh.3313. Epub 2012 Jul 9.
The aim of this study was to compare the characteristics of women who had and had not worked at night in terms of their risk factors for common disease, indicators of general health, social activities, employment, and sleep behavior.
The Million Women Study is a large prospective cohort study of women's health in the United Kingdom with 1.3 million women recruited during 1996-2001 (aged 50-64 years) through 66 National Health Service breast screening centers. We analyzed the data from a random sample of 41 652 participants who, in 2009-2010, reported their history of night work.
Of the participants, 1 in 8 women (13%) reported that they had ever worked at night and 1 in 50 (2%) reported working at night for ≥20 years. For 33 sociodemographic, behavioral, reproductive, and hormonal factors examined, 20 showed highly significant differences between "ever" and "never" night workers (P<0.0001); 12 showed significant trends by duration of night work (P<0.01). In particular, compared to women who had never worked at night, women who had worked at night were more likely to (i) be of lower socioeconomic status [the odds ratio (OR) for ever versus never night workers of being in the lowest third of socioeconomic status was 1.15, 99% confidence interval (95% CI) 1.06-1.25]; (ii) have ever used hormone replacement therapy (HRT) for the menopause (OR 1.43, 99% CI 1.33-1.55); (iii) be current smokers (OR 1.37, 99% CI 1.19-1.58); and (iv) be obese (OR 1.26, 99% CI 1.15-1.37). Compared to women who had never worked at night, women who had worked at night for ≥20 years were more likely to be (i) of lower socioeconomic status (OR 1.28, 99% CI 1.04-1.57); (ii) nulliparous (OR 1.47, 99% CI 1.12-1.91); (iii) current smokers (OR 1.63, 99% CI 1.18-2.25); and (iv) obese (OR 1.55, 99% CI 1.25-1.93). Former night workers were more likely than never night workers to report a range of sleep disturbances, including poor quality of sleep (OR 1.15, 99% CI 1.01-1.31) and having to take medication to sleep (OR 1.35, 99% CI 1.15-1.60).
Women who reported having worked at night were substantially different from those who reporting never having worked at night and many of the differences would put "ever night workers" at increased risks of cancer, vascular disease, and many other common conditions.
本研究旨在比较有夜间工作史和无夜间工作史的女性在常见疾病的风险因素、一般健康指标、社会活动、就业和睡眠行为方面的特征。
百万妇女研究是一项针对英国女性健康的大型前瞻性队列研究，于 1996-2001 年期间通过 66 个国家卫生服务部乳腺筛查中心招募了 130 万名年龄在 50-64 岁之间的女性。我们分析了 41652 名随机参与者的数据，这些参与者在 2009-2010 年报告了他们的夜间工作史。
在参与者中，1/8 的女性（13%）报告说她们曾有过夜间工作经历，1/50（2%）的女性报告说她们曾有过 20 年以上的夜间工作经历。对于 33 个社会人口统计学、行为学、生殖和激素因素进行了检查，20 个因素在“曾有”和“从未有”夜间工作的女性之间表现出显著差异（P<0.0001）；12 个因素随着夜间工作时间的延长呈显著趋势（P<0.01）。特别是，与从未有过夜间工作史的女性相比，有夜间工作史的女性更可能：（i）处于较低的社会经济地位[有夜间工作史的女性中，处于社会经济地位最低三分之一的比例为 1.15，99%置信区间（95%CI）为 1.06-1.25]；（ii）曾使用激素替代疗法（HRT）治疗更年期（OR 1.43，99%CI 1.33-1.55）；（iii）目前吸烟（OR 1.37，99%CI 1.19-1.58）；和（iv）肥胖（OR 1.26，99%CI 1.15-1.37）。与从未有过夜间工作史的女性相比，有夜间工作史≥20 年的女性更可能：（i）处于较低的社会经济地位（OR 1.28，99%CI 1.04-1.57）；（ii）从未生育过（OR 1.47，99%CI 1.12-1.91）；（iii）目前吸烟（OR 1.63，99%CI 1.18-2.25）；和（iv）肥胖（OR 1.55，99%CI 1.25-1.93）。前夜间工作者比从未有过夜间工作史的女性更有可能报告一系列睡眠障碍，包括睡眠质量差（OR 1.15，99%CI 1.01-1.31）和需要服用药物才能入睡（OR 1.35，99%CI 1.15-1.60）。
报告有夜间工作史的女性与报告从未有过夜间工作史的女性有很大的不同，其中许多差异将使“有夜间工作史的女性”患癌症、血管疾病和许多其他常见疾病的风险增加。
