Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, San Francisco, California 94143.
Department of Neuroscience, Carleton University, Ottawa, ON, Canada K1S 5B6.
Radiat Res. 2023 May;199(5):490-505. doi: 10.1667/rade-22-00153.1. Epub 2023 Mar 22.
The number of people living with dementia is rising globally as life expectancy increases. Dementia is a multifactorial disease. Due to the ubiquity of radiation exposure in medical and occupational settings, the potential association between radiation and dementia, and its subtypes (Alzheimer's and Parkinson's disease), is of particular importance. There has also been an increased interest in studying radiation induced dementia risks in connection with the long-term manned space travel proposed by The National Aeronautics and Space Administration (NASA). Our aim was to systematically review the literature on this topic, and use meta-analysis to generate a summary measure of association, assess publication bias and explore sources of heterogeneity across studies. We identified five types of exposed populations for this review: 1. survivors of atomic bombings in Japan; 2. patients treated with radiation therapy for cancer or other diseases; 3. occupationally exposed workers; 4. those exposed to environmental radiation; and 5. patients exposed to radiation from diagnostic radiation imaging procedures. We included studies that considered incident or mortality outcomes for dementia and its subtypes. Following PRISMA guidelines, we systematically searched the published literature indexed in PubMed between 2001 and 2022. We then abstracted the relevant articles, conducted a risk-of-bias assessment, and fit random effects models using the published risk estimates. After we applied our eligibility criteria, 18 studies were identified for review and retained for meta-analysis. For dementia (all subtypes), the summary relative risk was 1.11 (95% CI: 1.04, 1.18; P = 0.001) comparing individuals receiving 100 mSv of radiation to those with no exposure. The corresponding summary relative risk for Parkinson's disease incidence and mortality was 1.12 (95% CI 1.07, 1.17; P <0.001). Our results provide evidence that exposure to ionizing radiation increases the risk of dementia. However, our findings should be interpreted with caution due to the small number of included studies. Longitudinal studies with improved exposure characterization, incident outcomes, larger sample size, and the ability to adjust for effects of potential confounders are needed to better assess the possible causal link between ionizing radiation and dementia.
随着预期寿命的延长， 全球范围内患痴呆症的人数正在增加。痴呆症是一种多因素疾病。由于辐射在医疗和职业环境中的普遍存在，以及辐射与痴呆症及其亚型（阿尔茨海默病和帕金森病）之间的潜在关联，因此具有特别重要的意义。人们对研究与美国国家航空航天局（NASA）提出的长期载人航天旅行有关的辐射引起的痴呆症风险也越来越感兴趣。我们的目的是系统地回顾这一主题的文献，并使用荟萃分析生成关联的综合度量，评估发表偏倚并探索研究之间异质性的来源。我们确定了本综述的五类暴露人群：1. 日本原子弹爆炸幸存者；2. 接受放射治疗癌症或其他疾病的患者；3. 职业暴露工人；4. 暴露于环境辐射的人群；5. 接受诊断性放射成像程序辐射的患者。我们纳入了考虑痴呆症及其亚型的发病或死亡率结果的研究。我们遵循 PRISMA 指南，系统地在 PubMed 中搜索了 2001 年至 2022 年期间发表的文献。然后我们提取了相关文章，进行了风险偏倚评估，并使用已发表的风险估计值拟合了随机效应模型。在应用我们的入选标准后，确定了 18 项研究进行综述并保留进行荟萃分析。对于痴呆症（所有亚型），与未暴露于辐射的个体相比，接受 100 mSv 辐射的个体的汇总相对风险为 1.11（95%CI：1.04，1.18；P = 0.001）。帕金森病发病率和死亡率的相应汇总相对风险为 1.12（95%CI 1.07，1.17；P <0.001）。我们的结果提供了证据，表明暴露于电离辐射会增加痴呆症的风险。但是，由于纳入研究的数量较少，我们的发现应谨慎解释。需要进行具有改进的暴露特征、发病结局、更大样本量和调整潜在混杂因素影响能力的纵向研究，以更好地评估电离辐射与痴呆症之间可能存在的因果关系。
