Background Higher energetic costs for mobility are associated with declining gait speed, and slow gait is linked to cognitive decline and Alzheimer’s disease. However, the physiological underpinnings of gait and brain health have not been well explored. We examined the associations of the energetic cost of walking with brain volume in cognitively unimpaired adults from the Baltimore Longitudinal Study of Aging. Methods We used brain magnetic resonance imaging (MRI) data from 850 participants (mean baseline age 66.3 ± 14.5 years), of whom 451 had longitudinal MRI data (2.8 ± 1.0 MRI scans over 4.0 ± 2.0 years). The energetic cost of walking was assessed as the average energy expended (V̇O2) during 2.5 minutes of customary-paced overground walking. Multivariable linear mixed-effects models examined the associations between baseline energetic cost of walking and regional brain volumes adjusting for covariates. Results At baseline, higher energetic cost of walking was cross-sectionally associated with lower gray and white matter volumes within the frontal, parietal, and temporal lobes, as well as hippocampal, total brain, and larger ventricular volumes (all false-discovery rate [FDR] p < .05). A baseline energetic cost of walking × time interaction demonstrated that participants with higher energetic cost of walking had faster annual decline in hippocampal volume (FDR p = .02) and accelerated annual increase in ventricular volumes (FDR p = .02). Conclusions The energetic cost of walking is associated with gray and white matter volumes and subsequent hippocampal atrophy and ventricular enlargement. Collectively, these data suggest the energetic cost of walking may be an early marker of neurodegeneration that contributes to the gait brain connection.

中文翻译：

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中晚期行走和脑萎缩的能量消耗

背景 较高的移动能量成本与步态速度下降有关，而缓慢的步态与认知能力下降和阿尔茨海默病有关。然而，步态和大脑健康的生理基础尚未得到很好的探索。我们研究了巴尔的摩老龄化纵向研究中认知未受损的成年人步行的能量消耗与脑容量之间的关联。方法 我们使用来自 850 名参与者（平均基线年龄 66.3 ± 14.5 岁）的脑磁共振成像 (MRI) 数据，其中 451 人有纵向 MRI 数据（2.8 ± 1.0 次 MRI 扫描超过 4.0 ± 2.0 年）。步行的能量消耗被评估为在 2.5 分钟的常规节奏地上步行期间消耗的平均能量 (V̇O2)。多变量线性混合效应模型检查了步行的基线能量成本与调整协变量的区域脑容量之间的关联。结果 在基线时，较高的步行能量成本与额叶、顶叶和颞叶内的灰质和白质体积以及海马、全脑和更大的心室体积横断面相关（所有错误发现率 [ FDR] p < .05)。步行的基线能量成本×时间交互作用表明，步行能量成本较高的参与者海马体积年度下降更快（FDR p = .02），心室体积年度增加加速（FDR p = .02）。结论 步行的能量消耗与灰质和白质体积以及随后的海马萎缩和脑室扩大有关。总的来说，这些数据表明步行的能量消耗可能是神经退化的早期标志，有助于步态大脑连接。