Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA.
J Alzheimers Dis. 2022;90(4):1589-1599. doi: 10.3233/JAD-220646.
Cardiometabolic disorders (hypertension, diabetes) are key modifiable risk factors for Alzheimer's disease and related disorders. They often co-occur; yet, the extent to which they independently affect brain structure and function is unclear.
We hypothesized their combined effect is greater in associations with cognitive function and neuroimaging biomarkers of white matter (WM) health and cerebral perfusion in a diverse older adult cohort.
Participants aged 50-85 years received: clinical evaluation, oral glucose tolerance testing, neuroimaging, cognitive testing, and adjudication. Neuroimaging included: T1 (gray [GM]/WM segmentation, regional volumes/thicknesses); FLAIR (WM hyperintensity volume [WMHv]; arterial spin labeling (cerebral blood flow); diffusion tensor imaging (fractional anisotropy [FA]); and neurite orientation dispersion and density imaging (Free Water). Hypertension (HTN) and impaired glucose tolerance (IGT) were staged and cardiometabolic status was categorized (HTN only, IGT only, IGT+HTN, neither). Multivariable linear regression modeled associations with cognitive and neuroimaging measures (covariates: age, gender, race).
MRI was available for 478 participants (35% mild cognitive impairment, 10% dementia) with mean age 70±8 years, 74% with HTN, 61% with IGT, and 15% self-identified as Black/African-American. IGT+HTN was significantly associated with cognitive impairment, higher WM Free Water and WMHv, lower FA, and lower GM perfusion compared to neither factor. HTN alone was associated with poorer cognition and lower GM perfusion. Cardiometabolic factors were not associated with GM macrostructure (volumes, temporal lobe cortical thickness) or cognitive status.
HTN and its co-occurrence with IGT (HTN+IGT) were associated with lower global cognitive performance and reduced GM perfusion and impaired WM microstructure.
心血管代谢紊乱（高血压、糖尿病）是阿尔茨海默病和相关疾病的关键可改变风险因素。它们经常同时发生；然而，它们对大脑结构和功能的独立影响程度尚不清楚。
我们假设，在一个多样化的老年人群体中，它们与认知功能以及白质（WM）健康和脑灌注的神经影像学生物标志物的关联中，联合效应更大。
年龄在 50-85 岁的参与者接受了：临床评估、口服葡萄糖耐量测试、神经影像学、认知测试和裁决。神经影像学包括：T1（灰质[GM]/WM 分割、区域体积/厚度）；FLAIR（WM 高信号体积[WMHv]；动脉自旋标记（脑血流）；弥散张量成像（各向异性分数[FA]）；以及神经丝取向分散和密度成像（自由水）。高血压（HTN）和糖耐量受损（IGT）分期，心血管代谢状况分类（仅 HTN、仅 IGT、IGT+HTN、两者都没有）。多变量线性回归模型与认知和神经影像学测量相关（协变量：年龄、性别、种族）。
478 名参与者（35%轻度认知障碍，10%痴呆）的 MRI 可用，平均年龄 70±8 岁，74%有 HTN，61%有 IGT，15%自我认定为黑人和/或非裔美国人。与没有任何因素相比，IGT+HTN 与认知障碍、更高的 WM 自由水和 WMHv、更低的 FA 以及更低的 GM 灌注有关。仅 HTN 与较差的认知和较低的 GM 灌注有关。心血管代谢因素与 GM 宏观结构（体积、颞叶皮质厚度）或认知状态无关。
HTN 及其与 IGT 的同时发生（HTN+IGT）与较低的整体认知表现以及 GM 灌注减少和 WM 微观结构受损有关。
