Objective To investigate the association between long term residential exposure to road traffic and railway noise and risk of incident dementia. Design Nationwide prospective register based cohort study. Setting Denmark. Participants 1 938 994 adults aged ≥60 years living in Denmark between 1 January 2004 and 31 December 2017. Main outcome measures Incident cases of all cause dementia and dementia subtypes (Alzheimer’s disease, vascular dementia, and Parkinson’s disease related dementia), identified from national hospital and prescription registries. Results The study population included 103 500 participants with incident dementia, and of those, 31 219 received a diagnosis of Alzheimer’s disease, 8664 of vascular dementia, and 2192 of Parkinson’s disease related dementia. Using Cox regression models, 10 year mean exposure to road traffic and railway noise at the most (Ldenmax) and least (Ldenmin) exposed façades of buildings were associated with a higher risk of all cause dementia. These associations showed a general pattern of higher hazard ratios with higher noise exposure, but with a levelling off or even small declines in risk at higher noise levels. In subtype analyses, both road traffic noise and railway noise were associated with a higher risk of Alzheimer’s disease, with hazard ratios of 1.16 (95% confidence interval 1.11 to 1.22) for road Ldenmax ≥65 dB compared with <45 dB, 1.27 (1.22 to 1.34) for road Ldenmin ≥55 dB compared with <40 dB, 1.16 (1.10 to 1.23) for railway Ldenmax ≥60 dB compared with <40 dB, and 1.24 (1.17 to 1.30) for railway Ldenmin ≥50 dB compared with <40 dB. Road traffic, but not railway, noise was associated with an increased risk of vascular dementia. Results indicated associations between road traffic Ldenmin and Parkinson’s disease related dementia. Conclusions This nationwide cohort study found transportation noise to be associated with a higher risk of all cause dementia and dementia subtypes, especially Alzheimer’s disease. As this study is based on data from the Danish national registers, which belong to the Danish Ministry of Health and Statistics Denmark, the authors are not allowed to share data in raw form.

中文翻译：

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丹麦住宅交通噪音暴露与痴呆发病率：全国队列研究

目的调查长期住宅暴露于道路交通和铁路噪音与痴呆事件风险之间的关联。设计基于全国前瞻性登记的队列研究。设置丹麦。参与者 2004 年 1 月 1 日至 2017 年 12 月 31 日期间居住在丹麦的 1 938 994 名 60 岁以上的成年人。医院和处方登记处。结果 研究人群包括 103 500 名患有痴呆症的参与者，其中 31 219 人被诊断为阿尔茨海默病，8664 人被诊断为血管性痴呆，2192 人被诊断为帕金森病相关痴呆。使用 Cox 回归模型，10 年平均暴露于道路交通和铁路噪音最多 (Ldenmax) 和最少 (Ldenmin) 的建筑物外墙与更高的全因痴呆风险相关。这些关联显示出噪声暴露较高时风险比较高的一般模式，但在较高噪声水平下风险趋于平稳甚至小幅下降。在亚型分析中，道路交通噪声和铁路噪声都与阿尔茨海默病的高风险相关，道路 Ldenmax ≥65 dB 的风险比为 1.16（95% 置信区间 1.11 至 1.22），而<45 dB 的风险比为 1.27（1.22至 1.34) 公路 Ldenmin ≥55 dB 与 <40 dB 相比，1.16（1.10 至 1.23）铁路 Ldenmax ≥60 dB 与 <40 dB 相比，1.24（1.17 至 1.30）铁路 Ldenmin ≥50 dB 与 <40 D b。公路交通，但不是铁路，噪音与血管性痴呆风险增加有关。结果表明道路交通 Ldenmin 与帕金森病相关痴呆之间存在关联。结论 这项全国性队列研究发现，交通噪音与全因痴呆和痴呆亚型（尤其是阿尔茨海默病）的高风险相关。由于本研究基于属于丹麦卫生和丹麦统计部的丹麦国家登记处的数据，因此作者不得以原始形式共享数据。尤其是阿尔茨海默病。由于本研究基于属于丹麦卫生和丹麦统计部的丹麦国家登记处的数据，因此作者不得以原始形式共享数据。尤其是阿尔茨海默病。由于本研究基于属于丹麦卫生和丹麦统计部的丹麦国家登记处的数据，因此作者不得以原始形式共享数据。