Background

Age-related cognitive decline may be delayed with appropriate interventions if those at high risk can be identified prior to clinical symptoms arising. Gait variability assessment has emerged as a promising candidate prognostic indicator, however, it remains unclear how sensitive gait variability is to early changes in cognitive abilities.

Research question

Do community-dwelling adults over 65 years of age with subjective memory complaints differ from those with no subjective memory concerns in terms of laboratory-measured or free-living gait variability?

Methods

This cross-sectional study recruited 24 (age = 73.5(SD 6.4) years) community-dwelling people with subjective memory complaints and twenty seven (age = 70.9(4.3) years) individuals with no subjective memory concerns. A sample of 9 individuals with diagnosed mild dementia were also assessed (age = 86.5(7.0) years). Gait variability was assessed in a laboratory during walking at preferred pace (single-task) and while counting backward by seven (dual-task). Sixteen passes over a 4.88 m walkway in each condition were recorded and step length and duration variability was analysed. Free-living gait was assessed with a waist-worn accelerometer by identifying gait bouts of at least one min duration, and the mean multiscale sample entropy in one mins non-overlapping epochs is reported. Statistical inferences were based on analysis of variance using sex and group as the factors.

Results

No difference between those with subjective memory complaints and those without were observed in either laboratory- or free-living gait variability estimates. Both laboratory- and free-living gait variability were higher in those with mild dementia compared to the other groups.

Significance

Assuming that subjective memory complaints are on the pathway from cognitively intact to cognitively frail, the findings raise the hypothesis that subjective memory complaints occur earlier in the pathophysiology than measurable changes in laboratory or free living gait. Alternatively the gait variability assessments utilised may have been too insensitive.

中文翻译：

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基于实验室的步态变异性和习惯性步态熵不能将居住在社区的老年人与具有主观记忆投诉的老年人区分开。

背景

如果可以在临床症状出现之前识别出高危人群，则可以通过适当的干预措施来延迟与年龄有关的认知下降。步态变异性评估已成为一种有前途的候选预后指标，但是，目前尚不清楚步态变异性对认知能力的早期变化有多敏感。

研究问题

在实验室测量的或自由活动的步态变异性方面，患有主观记忆障碍的65岁以上社区成年人是否与没有主观记忆问题的成年人不同？

方法

这项横断面研究招募了24位（年龄= 73.5（SD 6.4）岁）有主观记忆投诉的社区居民和27位（年龄= 70.9（4.3）岁）没有主观记忆问题的人。还评估了9名诊断为轻度痴呆的个体的样本（年龄= 86.5（7.0）岁）。步态变异性是在实验室中以偏好的步伐（单任务）和倒数七（双任务）进行评估的。在每种情况下，在4.88 m的人行道上记录16次通过，并分析步长和持续时间的变异性。用腰部加速计通过确定至少一分钟的步态发作来评估自由活动步态，并报告一分钟非重叠时期内的平均多尺度样本熵。

结果

在实验室或自由生活步态变异性估计中，没有主观记忆抱怨的人与没有主观记忆抱怨的人之间没有差异。与其他组相比，轻度痴呆患者的实验室和自由活动步态变异性均较高。

意义

假设主观记忆障碍在从认知完好到虚弱的过程中，该发现提出了这样的假设：主观记忆障碍发生在病理生理学中比实验室或自由活动步态的可测量变化更早发生。或者，使用的步态变异性评估可能过于敏感。