A true understanding of the distribution and functional correlates of Alzheimer’s disease pathology in dementia-free older adults requires a population-based perspective. Here we report initial findings from a sample of 102 cognitively unimpaired participants (average age 77.2 years, 54.9% women, 13.7% APOE*4 carriers) recruited for neuroimaging from a larger representative population-based cohort participating in an ongoing longitudinal study of aging, the Monongahela-Youghiogheny Healthy Aging Team (MYHAT). All participants scored < 1.0 on the Clinical Dementia Rating (CDR) Scale, with 8 participants (7.8%) scoring CDR = 0.5. Participants completed a positron emission tomography scan using the tracers [C-11]Pittsburgh Compound-B (PiB) and [F-18]AV-1451 to estimate amyloid and tau deposition. PiB positivity was defined on a regional basis using established standardized uptake value ratio cutoffs (SUVR; cerebellar gray matter reference), with 39 participants (38.2%) determined to be PiB(+). Health history, lifestyle, and cognitive abilities were assessed cross-sectionally at the nearest annual parent MYHAT study visit. A series of adjusted regression analyses modeled cognitive performance as a function of global PiB SUVR and [F-18]AV-1451 SUVR in Braak associated regions 1, 3/4, and 5/6. In comparison to PiB(-) participants (n = 63), PiB(+) participants were older, less educated, and were more likely to be APOE*4 carriers. Global PiB SUVR was significantly correlated with [F-18]AV-1451 SUVR in all Braak-associated regions (r = .38–0.53, p < .05). In independent models, higher Global PiB SUVR and Braak 1 [F-18]AV-1451 SUVR were associated with worse performance on a semantic interference verbal memory test. Our findings suggest that brain amyloid is common in a community-based setting, and is associated with tau deposition, but both pathologies show few associations with concurrent cognitive performance in a dementia-free sample.

真正理解阿尔茨海默病病理在无痴呆老年人中的分布和功能相关性需要基于人群的观点。在这里，我们报告了来自 102 名认知未受损参与者样本的初步发现（平均年龄 77.2 岁，54.9% 为女性，13.7% APOE*4携带者）从一个更大的代表性人群队列中招募神经影像学，该队列参与正在进行的衰老纵向研究，即 Monongahela-Youghiogheny 健康衰老团队 (MYHAT)。所有参与者的临床痴呆评分 (CDR) 量表得分 < 1.0，其中 8 名参与者 (7.8%) 的 CDR = 0.5。参与者使用示踪剂 [C-11] 匹兹堡化合物 B (PiB) 和 [F-18]AV-1451 完成了正电子发射断层扫描，以估计淀粉样蛋白和 tau 沉积。PiB 阳性是在区域基础上使用已建立的标准化摄取值比率截止值（SUVR；小脑灰质参考）定义的，其中 39 名参与者 (38.2%) 被确定为 PiB(+)。在最近的年度父母 MYHAT 研究访问中对健康史、生活方式和认知能力进行了横断面评估。一系列调整后的回归分析将认知性能建模为 Braak 相关区域 1、3/4 和 5/6 中全局 PiB SUVR 和 [F-18]AV-1451 SUVR 的函数。与 PiB(-) 参与者 (n = 63) 相比，PiB(+) 参与者年龄较大，受教育程度较低，并且更有可能APOE*4载体。在所有 Braak 相关区域，全球 PiB SUVR 与 [F-18]AV-1451 SUVR 显着相关 (r = .38–0.53, p < .05)。在独立模型中，较高的 Global PiB SUVR 和 Braak 1 [F-18]AV-1451 SUVR 与语义干扰语言记忆测试中的较差性能相关。我们的研究结果表明，脑淀粉样蛋白在基于社区的环境中很常见，并且与 tau 沉积有关，但两种病理学都显示与无痴呆样本中的并发认知表现几乎没有关联。