Wang Xinghao, Chen Qian, Liu Yawen, Sun Jing, Li Jia, Zhao Pengfei, Cai Linkun, Liu Wenjuan, Yang Zhenghan, Wang Zhenchang, Lv Han
Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
Brain Commun. 2024 Mar 1;6(2):fcae077. doi: 10.1093/braincomms/fcae077. eCollection 2024.
To explore the causal relationship between age and brain health (cortical atrophy, white matter integrity, white matter hyperintensities and cerebral microbleeds in various brain regions) related multiparameter imaging features using two-sample Mendelian randomization. Age was determined as chronological age of the subject. Cortical volume, white matter micro-integrity, white matter hyperintensity volume and cerebral microbleeds of each brain region were included as phenotypes for brain health. Age and imaging of brain health related genetic data were analysed to determine the causal relationship using inverse-variance weighted model, validated by heterogeneity and horizontal pleiotropy variables. Age is causally related to increased volumes of white matter hyperintensities ( = 0.151). For white matter micro-integrity, fibres of the inferior cerebellar peduncle (axial diffusivity = -0.128, orientation dispersion index = 0.173), cerebral peduncle (axial diffusivity = -0.136), superior fronto-occipital fasciculus (isotropic volume fraction = 0.163) and fibres within the limbic system were causally deteriorated. We also detected decreased cortical thickness of multiple frontal and temporal regions ( < 0.05). Microbleeds were not related with aging ( > 0.05). Aging is a threat of brain health, leading to cortical atrophy mainly in the frontal lobes, as well as the white matter degeneration especially abnormal hyperintensity and deteriorated white matter integrity around the hippocampus.
使用两样本孟德尔随机化方法，探讨年龄与脑健康（各脑区的皮质萎缩、白质完整性、白质高信号和脑微出血）相关多参数成像特征之间的因果关系。年龄定义为受试者的实际年龄。将每个脑区的皮质体积、白质微完整性、白质高信号体积和脑微出血作为脑健康的表型。分析年龄与脑健康相关遗传数据的成像，使用逆方差加权模型确定因果关系，并通过异质性和水平多效性变量进行验证。年龄与白质高信号体积增加存在因果关系（ = 0.151）。对于白质微完整性，小脑下脚纤维（轴向扩散率 = -0.128，方向分散指数 = 0.173）、大脑脚（轴向扩散率 = -0.136）、额枕上束（各向同性体积分数 = 0.163）和边缘系统内的纤维出现因果性恶化。我们还检测到多个额叶和颞叶区域的皮质厚度降低（ < 0.05）。微出血与衰老无关（ > 0.05）。衰老对脑健康构成威胁，主要导致额叶皮质萎缩，以及白质变性，尤其是海马体周围异常高信号和白质完整性恶化。
