BACKGROUND The rising prevalence of dementia necessitates identifying early neurobiological markers of dementia risk. Reduced cerebral white matter volume and flattening of the slope of the electrophysiological 1/f spectral power distribution provide neurobiological markers of brain ageing alongside cognitive decline. However, their association with modifiable dementia risk remains to be understood. METHODS A cross-sectional sample of 98 healthy older adults (79 females, mean age = 65.44) underwent structural magnetic resonance imaging (sMRI), resting-state electroencephalography (EEG), cognitive assessments and dementia risk scoring using the CogDrisk framework. Univariate and multivariate linear regression models were conducted to investigate the relationships between modifiable dementia risk and sMRI brain volumes, the exponent of EEG 1/f spectral power, and cognition, whilst controlling for non-modifiable factors. RESULTS Smaller global white matter volume (F(1,87) = 6.884, R2 = 0.073, P = .010), and not grey (F(1,87) = 0.540, R2 = 0.006, P = .468) or ventricle volume (F(1,87) = 0.087, R2 = 0.001, P = .769), was associated with higher modifiable dementia risk. A lower exponent, reflecting a flatter 1/f spectral power distribution, was associated with higher dementia risk at frontal (F(1,92) = 4.096, R2 = 0.043, P = .046) but not temporal regions. No significant associations were found between cognitive performance and dementia risk. In multivariate analyses, both white matter volume and the exponent of the 1/f spectral power distribution independently associated with dementia risk. CONCLUSIONS Structural and functional neurobiological markers of early brain ageing, but not cognitive function, are independently associated with modifiable dementia risk in healthy older adults.

中文翻译：

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与较小的白质体积和改变的 1/f 非周期性大脑活动相关的可改变的痴呆风险：来自 LEISURE 研究的横断面见解。


背景 痴呆患病率的上升需要确定痴呆风险的早期神经生物学标志物。脑白质体积减少和电生理 1/f 光谱功率分布斜率变平提供了大脑衰老和认知能力下降的神经生物学标志物。然而，它们与可改变的痴呆风险的相关性仍有待了解。方法 使用 CogDrisk 框架对 98 名健康老年人 （79 名女性，平均年龄 = 65.44） 进行结构磁共振成像 （sMRI）、静息态脑电图 （EEG） 、认知评估和痴呆风险评分。进行单变量和多变量线性回归模型，以研究可改变的痴呆风险与 sMRI 脑容量、EEG 1/f 频谱功率指数和认知之间的关系，同时控制不可改变的因素。结果 较小的整体白质体积 （F（1,87） = 6.884，R2 = 0.073，P = .010），而不是灰色 （F（1,87） = 0.540，R2 = 0.006，P = .468） 或心室体积 （F（1,87） = 0.087，R2 = 0.001，P = .769），与较高的可改变痴呆风险相关。较低的指数反映出更平坦的 1/f 光谱功率分布，与额叶较高的痴呆风险相关 （F（1,92） = 4.096，R2 = 0.043，P = .046），但与颞区无关。在认知表现与痴呆风险之间没有发现显著关联。在多变量分析中，白质体积和 1/f 光谱功率分布的指数都与痴呆风险独立相关。 结论 早期大脑衰老的结构和功能神经生物学标志物，而不是认知功能，与健康老年人的可改变痴呆风险独立相关。