Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
Intramural Research Program, National Institute on Aging, Baltimore, Maryland, USA.
J Gerontol A Biol Sci Med Sci. 2022 Oct 6;77(10):2068-2076. doi: 10.1093/gerona/glab309.
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.
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.
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).
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.
行动的更高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充分探索。我们研究了在认知正常的巴尔的摩老龄化纵向研究参与者中，行走的能量成本与大脑体积之间的关系。
我们使用了 850 名参与者（平均基线年龄为 66.3 ± 14.5 岁）的脑磁共振成像（MRI）数据，其中 451 名参与者有纵向 MRI 数据（4.0 ± 2.0 年内进行了 2.8 ± 1.0 次 MRI 扫描）。行走的能量成本是通过 2.5 分钟的常规地面行走过程中平均消耗的能量（V̇O2）来评估的。多变量线性混合效应模型调整协变量后，研究了基线行走能量成本与区域脑体积之间的关系。
在基线时，较高的行走能量成本与额叶、顶叶和颞叶以及海马体、全脑和较大的脑室体积的灰质和白质体积降低存在横断面相关性（所有错误发现率 [FDR] p <.05）。基线行走能量成本与时间的交互作用表明，行走能量成本较高的参与者的海马体体积每年下降速度更快（FDR p =.02），脑室体积每年增加速度加快（FDR p =.02）。
行走的能量成本与灰质和白质体积以及随后的海马体萎缩和脑室扩大有关。总的来说，这些数据表明，行走的能量成本可能是神经退行性变的早期标志物，它有助于连接步态和大脑。
