Background and research question

The relationships of Arsenic (As) and selenium (Se) to Alzheimer’s Disease (AD) are not clearly known. This case-control observational study aims to investigate the possible relationship of these elements to the diagnosis and pathophysiology of the disease.

Methods

This case-control observational study was performed using 40 AD patients in different clinical stages and 40 healthy control subjects, living in a similar environment with low As exposure. The levels of As and Se in nail and hair were measured with Inductively Coupled Plasma Mass Spectrometry. The results were analysed with regards to clinical condition, age, disease duration, sex, education, living environment, and the relationship of the two elements using Mann Whitney U test and Spearman Rho or Pearson correlation tests as appropriate.

Results

The levels of As and Se were not related to age, disease duration, sex, education, or living environment in the study groups (p > 0.05). The levels of As and Se in hair and nail samples of all patients and patient subgroups were higher than those in the healthy subjects (p < 0.001). A positive correlation was found between the levels of As and Se in both hair and nail samples only in the patient group (p < 0.01).

Conclusion

According to the results, As and Se levels probably increase due to some metabolic or genetic factors affecting both of them together. There may be an increase in the unregulated pool (selenomethionine) and a decrease in the regulated pool of Se (selenosycteine) in AD. Our findings need verification and the subject seems to deserve more elaborate evaluations including genetic analyses and analysis of different chemical forms of these elements.

中文翻译：

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指甲和头发中的砷和硒测量显示与老年人阿尔茨海默病的重要关系

背景和研究问题

砷 (As) 和硒 (Se) 与阿尔茨海默病 (AD) 的关系尚不清楚。这项病例对照观察性研究旨在调查这些因素与疾病的诊断和病理生理学可能存在的关系。

方法

这项病例对照观察性研究使用了 40 名处于不同临床阶段的 AD 患者和 40 名健康对照受试者，他们生活在类似的低砷暴露环境中。用电感耦合等离子体质谱法测量指甲和头发中的 As 和 Se 水平。酌情使用Mann Whitney U检验和Spearman Rho或Pearson相关检验对临床状况、年龄、病程、性别、教育程度、生活环境以及这两个因素的关系进行分析。

结果

研究组的As和Se水平与年龄、病程、性别、教育程度或生活环境无关（p > 0.05）。所有患者和患者亚组的头发和指甲样本中的 As 和 Se 水平均高于健康受试者（p < 0.001）。仅在患者组的头发和指甲样本中发现 As 和 Se 的水平呈正相关（p < 0.01）。

结论

根据结果​​，As 和 Se 水平可能由于某些代谢或遗传因素共同影响两者而增加。AD 中未调节的池（硒代蛋氨酸）可能增加，而调节的硒池（硒代半胱氨酸）可能会减少。我们的研究结果需要验证，并且该主题似乎值得更详尽的评估，包括遗传分析和这些元素的不同化学形式的分析。