Park Ki Yun, Snyder Abraham Z, Goyal Manu S, Laumann Timothy O, Lee John J, Adeyemo Babatunde, Metcalf Nicholas, Vlassenko Andrei G, Shimony Joshua S, Leuthardt Eric C
Medical Scientist Training Program, Washington University School of Medicine, St. Louis, MO, 63110, USA.
Department of Neurological Surgery, Washington University School of Medicine, St. Louis, MO, 63110, USA.
Adv Sci (Weinh). 2025 Oct;12(37):e17644. doi: 10.1002/advs.202417644. Epub 2025 Jul 16.
Cerebral glucose metabolism (CMRGlc) systematically decreases with advancing age. We sought to identify correlates of decreased CMRGlc in the spectral properties of fMRI signals imaged in the task-free state. Lifespan resting-state fMRI data acquired in 455 healthy adults (ages 18-87 years) and cerebral metabolic data acquired in a separate cohort of 94 healthy adults (ages 25-45 years, 65-85 years) were analyzed. The spectral properties of the fMRI data were characterized in terms of the relative predominance of slow versus fast activity using the spectral slope (SS) measure. We found that the relative proportion of fast activity increases with advancing age (SS flattening) across most cortical regions. The regional distribution of spectral slope was topographically correlated with CMRGlc in young adults. Notably, whereas most older adults maintain a youthful pattern of SS topography, a distinct subset of older adults significantly diverged from the youthful pattern. This subset of older adults also diverged from the youthful pattern of CMRGlc metabolism. This divergent pattern was associated with T2-weighted signal changes in frontal lobe white matter, an independent marker of small vessel disease. These findings suggest that BOLD signal spectral slope flattening may represent a biomarker of age-associated neurometabolic pathology.
脑葡萄糖代谢（CMRGlc）会随着年龄的增长而系统性地下降。我们试图在静息状态下成像的功能磁共振成像（fMRI）信号的频谱特性中，找出CMRGlc下降的相关因素。分析了455名健康成年人（年龄在18 - 87岁之间）获取的全生命周期静息态fMRI数据，以及另一组94名健康成年人（年龄在25 - 45岁、65 - 85岁之间）获取的脑代谢数据。使用频谱斜率（SS）测量方法，根据慢活动与快活动的相对优势来表征fMRI数据的频谱特性。我们发现，在大多数皮质区域，快活动的相对比例会随着年龄的增长而增加（SS变平）。在年轻人中，频谱斜率的区域分布与CMRGlc在地形学上相关。值得注意的是，虽然大多数老年人保持着年轻的SS地形模式，但有一部分老年人明显偏离了年轻模式。这部分老年人也偏离了年轻的CMRGlc代谢模式。这种不同的模式与额叶白质的T2加权信号变化有关，T2加权信号变化是小血管疾病的一个独立标志物。这些发现表明，血氧水平依赖（BOLD）信号频谱斜率变平可能代表了与年龄相关的神经代谢病理学的一个生物标志物。
