Guan Dylan X, Chen Hung-Yu, Camicioli Richard, Montero-Odasso Manuel, Smith Eric E, Ismail Zahinoor
University of Toronto, Toronto, ON, Canada.
University of Calgary, Calgary, AB, Canada.
Exp Gerontol. 2022 Jun 1;162:111743. doi: 10.1016/j.exger.2022.111743. Epub 2022 Feb 16.
Mild behavioral impairment (MBI) and dual-task gait cost (DTGC) are two non-cognitive markers of dementia that capture behavioral and motor symptoms. We investigated the relationship between MBI and DTGC in a sample of non-demented older adults.
This was a cross-sectional observational study of 193 participants (10 cognitively normal, 48 subjective cognitive decline (SCD), 135 mild cognitive impairment (MCI); 52.8% female) from 13 Canadian sites from the Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND) study. The Neuropsychiatric Inventory Questionnaire (NPI-Q) was used to define MBI severity using a published algorithm. DTGC, the percentage difference between dual-task and preferred walking speeds, was assessed under three cognitive tasks: animal naming, counting backwards, and serial seven subtractions. Associations were tested in the entire cohort and in the MCI subgroup using multivariable linear regression adjusted for age, sex, education, and diagnosis. The role of global cognition, executive function, verbal and working memory in the association were investigated using tests of mediation and moderation.
MBI symptoms were present in 46.6% of participants (mean age = 72.4 years). Greater overall MBI burden was associated with lower gait speed across all conditions. Furthermore, a one-point increase in global MBI symptom severity was associated with a 0.8% increase in DTGC in the animal fluency condition, a 0.9% increase in the counting backwards condition and a 1.1% increase in the serial sevens condition. These associations were strongest in the subgroup of MCI participants. Executive function but not global cognition or verbal and working memory mediated the association between MBI and DTGC in all three conditions.
MBI is associated with gait speed and DTGC in this group of non-demented individuals, independent of the presence or absence of MCI. These findings provide evidence of the relationship between these non-cognitive dementia markers of behavior and gait beyond cognitive impairment.
轻度行为损害（MBI）和双任务步态成本（DTGC）是痴呆症的两种非认知标志物，可捕捉行为和运动症状。我们在一组非痴呆老年人样本中研究了MBI与DTGC之间的关系。
这是一项横断面观察性研究，研究对象为来自加拿大13个地点的193名参与者（10名认知正常、48名主观认知衰退（SCD）、135名轻度认知障碍（MCI）；女性占52.8%），来自神经退行性变和痴呆综合评估（COMPASS-ND）研究。使用神经精神科问卷（NPI-Q），通过已发表的算法来定义MBI严重程度。DTGC即双任务步行速度与偏好步行速度之间的百分比差异，在三项认知任务下进行评估：动物命名、倒数和连续减7。在整个队列和MCI亚组中，使用调整了年龄、性别、教育程度和诊断的多变量线性回归来测试关联。使用中介和调节测试来研究整体认知、执行功能、语言和工作记忆在该关联中的作用。
46.6%的参与者存在MBI症状（平均年龄=72.4岁）。在所有情况下，更高的总体MBI负担与更低的步态速度相关。此外，在动物流畅性任务中，总体MBI症状严重程度每增加1分，DTGC增加0.8%；在倒数任务中增加0.9%；在连续减7任务中增加1.1%。这些关联在MCI参与者亚组中最为明显。在所有三种情况下，执行功能而非整体认知、语言和工作记忆介导了MBI与DTGC之间的关联。
在这组非痴呆个体中，MBI与步态速度和DTGC相关，与MCI的存在与否无关。这些发现为这些行为和步态的非认知痴呆标志物之间超出认知障碍的关系提供了证据。
