Gérontopôle de Toulouse, Institut du Vieillissement, Centre Hospitalo-Universitaire de Toulouse, Toulouse, France.
France Faculté de Médecine, Unités mixtes de recherche (UMR) Institut national de la santé et de la recherche médicale (INSERM) 1027, University of Toulouse III, Toulouse, France.
J Am Geriatr Soc. 2020 May;68(5):1050-1055. doi: 10.1111/jgs.16343. Epub 2020 Jan 25.
Cross-sectional associations have been found between frail individuals and worse white matter (WM) integrity. However, the prospective association between WM integrity and frailty is still unclear. Our objectives were to measure associations between WM integrity using diffusion tensor imaging (DTI) and the 5-year worsening of frailty in community-dwelling older adults.
Secondary analysis of the randomized controlled Multidomain Alzheimer Preventive Trial (MAPT).
Thirteen memory centers in France and Monaco between 2008 and 2011.
Participants (mean age = 74.7 ± 3.9 years) with no dementia at baseline who had functional magnetic resonance imaging performed as part of the MAPT study (n = 227).
Fractional anisotropy and mean diffusivity (MD), axial diffusivity (AxD), and radial diffusivity (RD) were acquired for 10 different brain regions. Frailty was assessed by the Fried frailty phenotype (score from 0 to 5, higher is worse) at up to seven time points for 5 years. Mixed effect ordinal logistic regression model was used to assess the prospective association between DTI parameters (independent variables) and frailty (dependent variable). All the analyses were adjusted for age, sex, baseline total intracranial volume, and the presence of one of the following cardiovascular risk factors (hypertension, diabetes, and/or hypercholesterolemia).
A statistically significant association was found between the RD, AxD, and MD for different brain regions (anterior limb of internal capsule, external capsule, posterior corona radiata, posterior thalamic radiation, superior corona radiata, superior frontal occipital fasciculus, and superior longitudinal fasciculus) and worsening of frailty over 5 years after adjusting for multiple comparisons.
This is the first study to show that WM integrity is associated with frailty in older adults. The mechanisms related to these results require further investigation. J Am Geriatr Soc 68:1050-1055, 2020.
已有研究发现虚弱个体与脑白质（WM）完整性较差之间存在横断面关联。然而，WM 完整性与虚弱之间的前瞻性关联尚不清楚。我们的目的是使用弥散张量成像（DTI）测量社区居住的老年人群中 WM 完整性与虚弱 5 年恶化之间的相关性。
多领域阿尔茨海默病预防试验（MAPT）的二次分析。
2008 年至 2011 年法国和摩纳哥的 13 个记忆中心。
基线时无痴呆症且作为 MAPT 研究一部分进行功能磁共振成像的参与者（n=227；平均年龄=74.7±3.9 岁）。
获得 10 个不同脑区的分数各向异性和平均弥散度（MD）、轴向弥散度（AxD）、径向弥散度（RD）。虚弱通过 Fried 虚弱表型（0 至 5 分，分数越高越差）评估，5 年内最多 7 次评估。混合效应有序逻辑回归模型用于评估 DTI 参数（自变量）与虚弱（因变量）之间的前瞻性关联。所有分析均调整了年龄、性别、基线总颅内体积以及以下心血管危险因素（高血压、糖尿病和/或高胆固醇血症）之一的存在。
调整了多项比较后，发现不同脑区（内囊前肢、外囊、后放射冠、后丘脑辐射、上放射冠、额枕上束和上纵束）的 RD、AxD 和 MD 与 5 年内虚弱恶化之间存在统计学显著关联。
这是第一项表明 WM 完整性与老年人虚弱相关的研究。与这些结果相关的机制需要进一步研究。美国老年学会杂志 68：1050-1055，2020 年。
