Awareness of the mortality risk of people diagnosed with mild cognitive impairment (MCI) has recently emerged, increasing scientific interest in the particularities of this neurocognitive syndrome. Mortality in MCI is studied far less than in dementia. Population-based studies have found lower mortality rates than those found in specialized clinics and research settings, which could be due to selection bias and different methods of characterizing impairment. Additionally, while published data on the association between cognitive decline and mortality from high-income countries is abundant, there is little data from lowand middle-income populations. The results of Campos et al. provide important detail that higher mortality is associated with cognitive impairment in community-dwelling older adults from a middleincome country. In this interesting and relevant study, a branch of the Bambuı́ Cohort Study of Aging, 1,281 older adults from a small rural town in southeastern Brazil were followed for 13.3 years. The large sample size, the fact the investigators sought to include the entire older adult population of the study area, and the long observational time are clear strengths. The investigators managed to collect baseline data on cognitive and clinical parameters and explored the association between different severity levels of cognitive impairment and long-term mortality risk. A positive association was found between moderate cognitive decline, male gender, and higher mortality rates. The authors stratified the severity of cognitive impairment according to standard deviation patterns of Mini-Mental State Examination scores. Mild and moderate cognitive impairment were respectively defined by scores of -1.0 and -2.0 standard deviations below the cutoff means. The default procedure when ascertaining the severity of cognitive decline and establishing a dementia diagnosis must also rely on functionality parameters, such as performing activities of daily living. Although the authors did investigate functional impairment in abilities such as dressing, walking across a room, bathing/showering, eating, getting in/out of bed, and toilet use, this data was not specifically contemplated for discriminating between degrees of cognitive impairment. Nevertheless, moderately impaired participants, as defined by Mini-Mental State Examination scores, had a higher prevalence of functional disability (28.6%) than those with MCI (13.5%) or those who were unimpaired (8.8%) (p = 0.003). Another important methodological aspect was that cognition was only assessed upon enrollment using screening instruments. No longitudinal follow-up data on cognition and functional status was performed. MCI is a heterogeneous syndrome that could involve underlying neurodegenerative diseases, but may also be due to potentially reversible conditions, such as depression, vitamin deficiencies, or metabolic (e.g. thyroid) disorders. Although this limitation must be taken into account, previous populational studies have used similar methodologies to address long-term mortality risks in mild and moderate cognitive decline. Sub-categorizing MCI by its distinct endophenotypes (i.e., amnestic vs. non-amnestic, singlevs. multiple domain MCI) could provide important details about the association between mortality and specific underlying etiologies. In fact, one longitudinal study compared mortality rates from 1,292 healthy participants and 862 participants with MCI, which was stratified according to the number and type of affected cognitive domains. A higher overall mortality risk was found in the MCI group than healthy controls, as well as in the non-amnestic vs. amnestic MCI group. Male gender, lack of physical activity, and a history of heart disease (which suggests the importance of the vascular disease burden) were also associated with higher mortality risk. With respect to baseline socio-demographic features, the three cognitive impairment groups (none, mild, and moderate) were significantly different (p o 0.0001) concerning age and education. Participants with mild and moderate cognitive impairment were older, while the percentages of those with less than four years of education were 59.5%, 93.6%, and 95.2%, respectively, for subjects with no, mild, and moderate cognitive dysfunction. A number of clinical characteristics also deserve attention. There were statistically significant differences (p o 0.0001) among groups with no, mild, or moderate cognitive dysfunction regarding Trypanosoma cruzi infection (34.4, 54.8, and 76.2%, respectively) and depressive symptoms (34.9, 47.6, and 76.2%, respectively). T. cruzi infection is endemic to rural southeastern Brazil (where the study was conducted) and is a major cause

中文翻译：

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认知障碍：老年男性死亡的（非）依赖风险因素？

最近出现了对被诊断患有轻度认知障碍 (MCI) 的人的死亡风险的认识，增加了对这种神经认知综合征特殊性的科学兴趣。MCI 死亡率的研究远远少于痴呆症。基于人群的研究发现死亡率低于专科诊所和研究环境中的死亡率，这可能是由于选择偏倚和表征损伤的不同方法。此外，虽然高收入国家已发表的关于认知能力下降与死亡率之间关联的数据很多，但中低收入人群的数据却很少。Campos 等人的结果。提供重要的细节，表明较高的死亡率与来自中等收入国家的社区老年人的认知障碍有关。在这项有趣且相关的研究中，Bambuı́ 老龄化队列研究的一个分支对来自巴西东南部一个乡村小镇的 1,281 名老年人进行了 13.3 年的随访。大样本量、研究人员试图包括研究区域的整个老年人口的事实以及较长的观察时间是明显的优势。研究人员设法收集了关于认知和临床参数的基线数据，并探讨了不同严重程度的认知障碍与长期死亡风险之间的关联。发现中度认知能力下降、男性和较高死亡率之间存在正相关。作者根据简易精神状态检查分数的标准偏差模式对认知障碍的严重程度进行分层。轻度和中度认知障碍分别由低于临界值的 -1.0 和 -2.0 标准差的分数定义。确定认知能力下降的严重程度和确定痴呆症诊断的默认程序还必须依赖于功能参数，例如进行日常生活活动。尽管作者确实调查了穿衣、穿过房间、洗澡/淋浴、进食、上床/下床和上厕所等能力方面的功能障碍，但这些数据并未专门用于区分认知障碍的程度。尽管如此，根据简易精神状态检查分数定义的中度受损参与者，其功能障碍患病率 (28.6%) 高于 MCI (13.5%) 或未受损 (8.8%) 的参与者 (p = 0.003)。另一个重要的方法论方面是认知仅在使用筛选工具注册时进行评估。没有进行关于认知和功能状态的纵向随访数据。MCI 是一种异质性综合征，可能涉及潜在的神经退行性疾病，但也可能是由于潜在的可逆疾病，例如抑郁症、维生素缺乏症或代谢（例如甲状腺）疾病。尽管必须考虑到这一限制，但之前的人口研究已经使用类似的方法来解决轻度和中度认知能力下降的长期死亡风险。通过其不同的内表型（即遗忘性与非遗忘性、单域与多域 MCI）对 MCI 进行子分类可以提供有关死亡率与特定潜在病因之间关联的重要细节。实际上，一项纵向研究比较了 1,292 名健康参与者和 862 名 MCI 参与者的死亡率，MCI 根据受影响认知领域的数量和类型进行分层。MCI 组的总体死亡风险高于健康对照组，以及非遗忘与遗忘 MCI 组。男性、缺乏体力活动和心脏病史（这表明血管疾病负担的重要性）也与较高的死亡风险相关。关于基线社会人口特征，三个认知障碍组（无、轻度和中度）在年龄和教育方面存在显着差异 (po 0.0001)。轻度和中度认知障碍的参与者年龄较大，而受教育不足四年的参与者比例为 59.5%，对于无、轻度和中度认知功能障碍的受试者，分别为 93.6% 和 95.2%。许多临床特征也值得关注。在克氏锥虫感染（分别为 34.4、54.8 和 76.2%）和抑郁症状（分别为 34.9、47.6 和 76.2%）方面，无、轻度或中度认知功能障碍的组之间存在统计学显着差异 (po 0.0001)。T. cruzi 感染是巴西东南部农村地区（进行研究的地方）的地方病，是一个主要原因 8 和 76.2%）和抑郁症状（分别为 34.9、47.6 和 76.2%）。T. cruzi 感染是巴西东南部农村地区（进行研究的地方）的地方病，是一个主要原因 8 和 76.2%）和抑郁症状（分别为 34.9、47.6 和 76.2%）。T. cruzi 感染是巴西东南部农村地区（进行研究的地方）的地方病，是一个主要原因