BACKGROUND Lack of awareness of cognitive decline (ACD) has been described at the preclinical and prodromal stages of Alzheimer's disease (AD). In this study, we introduced a meta-memory ratio (MMR) and explored how it is associated with neuroimaging AD biomarkers in asymptomatic individuals at risk for AD. METHOD Four hundred forty-eight cognitively healthy participants from two cohorts of subjective memory complainers (INSIGHT-PreAD and ADNI) were included. Regression models were used to assess the impact of AD biomarkers on the MMR. RESULT In both cohorts, there was a significant quadratic effect of cerebral amyloidosis on the MMR value. In particular, participants had a high ACD up to the amyloid positivity threshold, above which a decrease of ACD was eventually observed as the amyloid load increased. CONCLUSION This nonlinear evolution of ACD in very early AD must be taken into account in clinical care and for trial enrollment as well.

中文翻译：

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元内存比率：一种新的独立于队列的方法，用于评估处于无风险的阿尔茨海默氏病患者中的认知能力。

背景技术在阿尔茨海默氏病（AD）的临床前和前驱阶段已经描述了对认知下降（ACD）的缺乏认识。在这项研究中，我们介绍了元记忆比（MMR），并探讨了它与无症状AD风险个体中的神经影像AD生物标记物之间的关系。方法包括来自两个主观记忆抱怨者（INSIGHT-PreAD和ADNI）队列的448个认知健康参与者。回归模型用于评估AD生物标志物对MMR的影响。结果在两个队列中，脑淀粉样变性对MMR值均具有显着的二次方影响。特别地，参与者具有高达淀粉样蛋白阳性阈值的高ACD，超过此阈值，随着淀粉样蛋白负荷的增加，最终观察到ACD降低。