Cerebral Blood Flow and Amyloid-β Interact to Affect Memory Performance in Cognitively Normal Older Adults.
Cerebral Blood Flow and Amyloid-β Interact to Affect Memory Performance in Cognitively Normal Older Adults.
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DOI：
10.3389/fnagi.2017.00181
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发表时间：
2017
影响因子：
4.8
通讯作者：
Delano-Wood L
中科院分区：
文献类型：
--
作者：
Bangen KJ;Clark AL;Edmonds EC;Evangelista ND;Werhane ML;Thomas KR;Locano LE;Tran M;Zlatar ZZ;Nation DA;Bondi MW;Delano-Wood L
脑血流（CBF）改变和淀粉样蛋白-β (Aβ)积累与老年痴呆症风险的认知缺陷独立相关。对于CBF和Aβ如何相互作用影响认知正常老年人的认知，我们所知甚少。因此，我们研究了来自阿尔茨海默病神经影像学倡议（ADNI）研究的老年人样本中，在阿尔茨海默病（AD）典型影响区域中CBF和a β状态之间的潜在统计相互作用。62名认知正常的参与者（平均年龄= 72岁）接受了神经成像和记忆测试。动脉自旋标记磁共振成像定量CBF， florbetapir PET淀粉样蛋白成像测定Aβ沉积。Aβ状态（即阳性与阴性）是根据既定的截止值确定的。使用雷伊听觉语言学习测试来评估记忆。调整了年龄、教育程度和性别的线性回归模型表明，脑脑血流和Aβ状态对记忆表现有显著的相互作用。在Aβ阳性的老年人中，海马、后扣带和楔前叶的CBF升高与记忆力下降呈显著负相关。相比之下，在Aβ阴性的老年人中，CBF和认知之间没有显着关联。我们的研究结果通过报道a β状态和CBF对记忆表现的相互作用，扩展了之前CBF对痴呆风险的研究。结果表明，与Aβ阴性个体相比，健康、无症状的Aβ阳性老年人可以识别出不同的cbf认知关联。在a β阳性老年人中，高CBF与较差记忆之间的关联可能反映了细胞和/或血管对病理过程的代偿反应，因此需要高CBF来维持正常的记忆能力。研究结果表明，脑血流及其与认知的关联可能在阿尔茨海默病早期干预可能有益的情况下作为脑功能的可靠标记物。
Cerebral blood flow (CBF) alterations and amyloid-β (Aβ) accumulation have been independently linked to cognitive deficits in older adults at risk for dementia. Less is known about how CBF and Aβ may interact to affect cognition in cognitively normal older adults. Therefore, we examined potential statistical interactions between CBF and Aβ status in regions typically affected in Alzheimer’s disease (AD) within a sample of older adults from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) study. Sixty-two cognitively normal participants (mean age = 72 years) underwent neuroimaging and memory testing. Arterial spin labeling magnetic resonance imaging was used to quantify CBF and florbetapir PET amyloid imaging was used to measure Aβ deposition. Aβ status (i.e., positivity versus negativity) was determined based on established cutoffs. The Rey Auditory Verbal Learning Test was used to assess memory. Linear regression models adjusted for age, education, and sex, demonstrated significant interactions between CBF and Aβ status on memory performance. Among Aβ positive older adults, there were significant negative associations between higher CBF in hippocampus, posterior cingulate, and precuneus and poorer memory performance. In contrast, among Aβ negative older adults, there were no significant associations between CBF and cognition. Our findings extend previous CBF studies of dementia risk by reporting interactions between Aβ status and CBF on memory performance in a sample of well-characterized, cognitively normal older adults. Results suggest that differential CBF-cognition associations can be identified in healthy, asymptomatic Aβ positive older adults relative to Aβ negative individuals. Associations between higherCBF and poorer memory among Aβ positive older adults may reflect a cellular and/or vascular compensatory response to pathologic processes whereby higher CBF is needed to maintain normal memory abilities. Findings indicate that CBF and its associations with cognition may have utility as a reliable marker of brain function early in the AD process when interventions are likely to be beneficial.