Alzheimer's disease patients (AD), as well as AD transgenic mice, are characterized by increased frailty. Furthermore, the assessment of frailty status represents a feasible approach for detecting individuals prone to develop more severe form of AD and for measuring the outcome of existing and putative AD therapeutics. The 5xFAD mouse is one of the widely used transgenic animal models of AD, but frailty in this model is scantly investigated. We used two validated mouse frailty assessment tools: phenotypic frailty score (FS) and clinical frailty index (FI) to investigate age- and sex- related differences in frailty status in 5xFAD mice. These tools measure different age-related deficits and do not necessarily identify the same subpopulations as frail. We detected a significant increase in frailty with age in both sexes, although females were surprisingly less frail than males. Depending on the tools used, a notable difference in frailty status was detected, with frailty index and frailty score identifying different mice as frail. These results warrant great caution when choosing the frailty tool and point to the need for further adaptation of frailty measurements in mouse models of AD.

中文翻译：

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脆弱指数和表型脆弱评分：阿尔茨海默氏病5XFAD转基因小鼠模型中与性别和年龄相关的差异。

阿尔茨海默氏病患者（AD）以及AD转基因小鼠的特征是身体虚弱。此外，对脆弱状态的评估代表了一种可行的方法，可用于检测易于发展为更严重形式的AD的个体并测量现有和公认的AD治疗方法的结果。5xFAD小鼠是广泛使用的AD转基因动物模型之一，但对该模型的脆弱性却很少进行研究。我们使用了两个经过验证的小鼠脆弱性评估工具：表型脆弱性评分（FS）和临床脆弱性指数（FI）来研究5xFAD小鼠的衰老状态与年龄和性别相关的差异。这些工具衡量与年龄相关的不同赤字，不一定将相同的亚群识别为虚弱的人。我们发现，随着年龄的增长，女性的脆弱性会显着增加，尽管女性出人意料地不如男性脆弱。根据所使用的工具，检测到脆弱状态存在显着差异，并且脆弱指数和脆弱评分将不同的小鼠识别为脆弱。这些结果在选择脆弱性工具时非常谨慎，并指出需要进一步调整AD鼠标模型中的脆弱性测量。