Mesial temporal lobe (MTL) is prominently affected in normal aging and associated with neurodegeneration in AD. Whether or not MTL atrophy is dependent on increasing amyloid load before the emergence of cognitive deficits is still disputed. We performed a 4.5-year longitudinal study in 75 older community dwellers (48 women, mean age: 79.3 years) including magnetic resonance imaging at baseline and follow-up, positron emission tomography amyloid during follow-up, neuropsychological assessment at 18 and 55 months, and APOE genotyping. Linear regression models were used to identify predictors of the MTL volume loss. Amyloid load was negatively associated with bilateral MTL volume at baseline explaining almost 10.5% of its variability. In multivariate models including time of follow-up and demographic variables (older age, male gender), this percentage exceeded 35%. The APOE4 allele independently contributed another 6%. Cognitive changes had a modest but still significant negative association with MTL volume loss. Our data support a multifactorial model including amyloid deposition, older age, male gender, APOE4 allele, and slight decline of cognitive abilities as independent predictors of MTL volume loss in brain aging.

中文翻译：

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具有保留认知的老年人中颞叶内侧体积减少的决定因素：纵向 PET 淀粉样蛋白研究

内侧颞叶 (MTL) 在正常衰老过程中受到显着影响，并与 AD 中的神经变性相关。MTL 萎缩是否依赖于在认知缺陷出现之前增加的淀粉样蛋白负荷仍存在争议。我们对 75 名老年社区居民（48 名女性，平均年龄：79.3 岁）进行了一项为期 4.5 年的纵向研究，包括基线和随访时的磁共振成像、随访期间的正电子发射断层扫描淀粉样蛋白、18 个月和 55 个月时的神经心理学评估和 APOE 基因分型。使用线性回归模型来确定 MTL 体积损失的预测因子。淀粉样蛋白负荷与基线时的双侧 MTL 体积呈负相关，解释了其变异性的近 10.5%。在包括随访时间和人口统计学变量（年龄较大、男性）在内的多变量模型中，这个百分比超过了 35%。APOE4 等位基因独立贡献了另外 6%。认知变化与 MTL 体积损失有适度但仍然显着的负相关。我们的数据支持一个多因素模型，包括淀粉样蛋白沉积、老年、男性、APOE4 等位基因和认知能力的轻微下降，作为脑衰老中 MTL 体积损失的独立预测因子。