Department of Geriatric Medicine and Memory Clinic, Angers University Hospital, UPRES EA 4638, University of Angers, Angers, France.
Service de Physiologie Clinique et de l'Exercice, CHU Saint-Etienne, Saint-Etienne, France.
Dement Geriatr Cogn Disord. 2018;45(1-2):18-26. doi: 10.1159/000485793. Epub 2018 Feb 27.
Vitamin K antagonists (VKAs) are commonly used for their role in haemostasis by interfering with the vitamin K cycle. Since vitamin K also participates in brain physiology, this voxel-based morphometric study aimed to determine whether the duration of exposure to VKAs correlated with focal brain volume reduction in older adults.
In this exposed/unexposed (1: 2) study nested within the GAIT (Gait and Alzheimer Interactions Tracking) cohort, 18 participants exposed to VKA (mean age 75 ± 5 years; 33.3% female; mean exposure 2,122 ± 1,799 days) and 36 matched participants using no VKA (mean age 75 ± 5 years; 33.3% female) underwent MRI scanning of the brain. Cortical grey and white matter volumes were automatically segmented using statistical parametric mapping. Age, gender, educational level, history of atrial fibrillation, type of MRI, and total intracranial volume were included as covariables.
The duration of exposure to VKA correlated inversely across the whole brain with the subvolumes of two clusters in the grey matter (right frontal inferior operculum and right precuneus) and one cluster in the white matter (left middle frontal gyrus). In contrast, the grade of white matter hyperintensities did not differ according to the use of VKA.
We found focal atrophies in older adults exposed to VKA. These findings provide new insights elucidating the effects of VKAs on brain health and function in older adults.
维生素 K 拮抗剂（VKAs）通过干扰维生素 K 循环在止血中发挥作用，因此被广泛应用。由于维生素 K 也参与大脑生理功能，本基于体素的形态计量学研究旨在确定老年人群中暴露于 VKAs 的时间长短是否与局部脑容量减少相关。
在 GAIT（步态和阿尔茨海默病相互作用追踪）队列中，进行了一项暴露组/未暴露组（1:2）的研究，18 名使用 VKA 的暴露组参与者（平均年龄 75±5 岁；33.3%为女性；平均暴露时间 2122±1799 天）和 36 名未使用 VKA 的匹配参与者（平均年龄 75±5 岁；33.3%为女性）接受了脑部 MRI 扫描。使用统计参数映射自动分割皮质灰质和白质体积。年龄、性别、教育程度、心房颤动史、MRI 类型和总颅内体积被纳入协变量。
在整个大脑中，VKA 暴露时间与灰质两个亚区（右侧额下回和右侧楔前叶）和一个白质亚区（左侧额中回）的体积呈负相关。相比之下，根据是否使用 VKA，脑白质高信号的严重程度没有差异。
我们发现暴露于 VKA 的老年人群中存在局部萎缩。这些发现提供了新的见解，阐明了 VKAs 对老年人群大脑健康和功能的影响。
