Department of Psychiatry, The University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
J Alzheimers Dis. 2012;30(3):639-49. doi: 10.3233/JAD-2012-120055.
The cognitive correlates of functional status are essential to dementia case-finding. Nevertheless, cognitive performance is a generally weak predictor of functional outcomes. We have employed structural equation models to explicitly distinguish functional status, and therefore "dementia-relevant" variance in cognitive task performance (i.e., δ) from the variance that is unrelated to a dementing process (i.e., g'). Together, g' + δ encompass Spearman's g. Although δ represents only a small fraction of the total variance in cognitive task performance, it is more strongly associated with dementia status than is g'. In this study, we validate δ in a well characterized Alzheimer's disease cohort, the Texas Alzheimer's Research and Care Consortium. Our approach results in "error free" continuous variables. This suggests that δ can serve as a dementia specific endophenotype. As a result, future studies may be able to associate δ with inflammatory and genetic biomarkers.
认知功能与功能状态密切相关，是痴呆病例发现的关键。然而，认知表现通常是功能结果的一个较弱预测因子。我们采用结构方程模型，明确区分功能状态，以及认知任务表现中与痴呆相关的（即 δ）和与痴呆过程无关的（即 g'）差异。g' + δ包含 Spearman 的 g。虽然 δ 仅占认知任务表现总方差的一小部分，但它与痴呆状态的相关性强于 g'。在这项研究中，我们在一个特征明确的阿尔茨海默病队列（德克萨斯州阿尔茨海默病研究和护理联合会）中验证了 δ。我们的方法产生了“无误差”的连续变量。这表明 δ 可以作为痴呆症的特定表型。因此，未来的研究可能能够将 δ 与炎症和遗传生物标志物联系起来。
