Institute and Policlinic for Occupational Medicine, Environmental Medicine and Prevention Research, University Hospital of Cologne, Cologne, Germany.
Eur J Epidemiol. 2019 Jan;34(1):1-4. doi: 10.1007/s10654-018-0469-6. Epub 2018 Dec 13.
Circadian disruption (CD) was implicated in chains of cancer causation when the International Agency for Research on Cancer classified shift-work involving circadian disruption as probably carcinogenic in 2007. In the following decade, epidemiological studies into causal concepts associated with circadian disruption were inconclusive. Unappreciated complexity with an exclusive focus on shift-work, light-at-night, sleep, and melatonin in regard to circadian disruption may be accountable. With compelling non-epidemiological evidence, we posit that ubiquitous circadian disruption causes cancer and, moreover, that this is unexplored epidemiologically. This hypothesis offers a novel explanation why numerous studies in shift-workers evince inconsistent results: If circadian disruption is a ubiquitous causal phenomenon, confining assessments to the workplace, ignoring circadian disruption at play, and potential misclassification of 'who' is 'when' and 'how much' exposed to circadian disruption may disallow detecting the existence and magnitude of cancer risks. The rationale herein provides plausible explanations for previous observations and makes falsifiable predictions.
当国际癌症研究机构在 2007 年将涉及昼夜节律打乱的轮班工作归类为可能致癌物质时，昼夜节律打乱与癌症因果关系链就被牵涉其中。在接下来的十年中，关于与昼夜节律打乱相关的因果概念的流行病学研究没有得出明确的结论。昼夜节律打乱可能与只关注轮班工作、夜间光照、睡眠和褪黑素有关，其复杂性尚未被充分认识。有令人信服的非流行病学证据表明，无处不在的昼夜节律打乱会导致癌症，而且这在流行病学上尚未得到探索。这一假设提供了一个新的解释，说明为什么在轮班工人中进行的许多研究结果不一致：如果昼夜节律打乱是一种普遍存在的因果现象，将评估仅限于工作场所，忽略了正在发挥作用的昼夜节律打乱，以及对“谁”在“何时”和“多少”受到昼夜节律打乱的潜在错误分类，可能会导致无法检测到癌症风险的存在和程度。本文中的基本原理为之前的观察结果提供了合理的解释，并做出了可验证的预测。
