Background This study aimed to examine if the association of cerebral perfusion with gait speed differs across systolic blood pressure (SBP) and age. Methods Cerebral perfusion was measured via arterial spin-labelled (ASL)-MRI among community-dwelling adults aged 31-94 years in the population-based Mayo Clinic Study of Aging. Usual gait speed was assessed over 5.6 meters on an electronic mat. Sex- and BMI-adjusted linear regression models estimated cross-sectional gait speed associations with ASL and modifying effects of age and SBP using 3-way and 2-way interaction terms between continuous age, SBP, and ASL. Results report estimated differences in gait speed per standard deviation (SD) lower ASL for exemplar SBPs and ages. Results Among 479 participants (mean age 67.6 years; 44% women; mean gait speed 1.17m/s), ASL relations to gait speed varied by age (ASL-x-age interaction: p=0.001) and SBP (ASL-x-SBP interaction: p=0.009). At an SBP of 120mmHg, each SD lower ASL was associated with a 0.04 m/s (95% CI: 0.01,0.07) slower gait speed at 65 years, 0.07 m/s (0.04,0.10) at 75 years, and 0.09 m/s (0.05,0.13) at 85 years. At an SBP of 140 mmHg, ASL associations with gait speed were attenuated to 0.01 (-.01,0.04), 0.04 (0.02,0.06) and 0.06 (0.04,0.09) m/s slower gait speed at ages 65, 75 and 85, respectively. Conclusion Poorer cerebral perfusion is associated with clinically meaningful slower gait speeds, particularly with older age, while higher perfusion markedly attenuates age differences in gait speed.

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跨收缩压水平和年龄的脑灌注与步态速度的关系：一项队列研究

背景 本研究旨在检查脑灌注与步态速度的关联是否因收缩压 (SBP) 和年龄而异。方法 在基于人口的 Mayo Clinic 老龄化研究中，通过动脉自旋标记 (ASL)-MRI 测量 31-94 岁社区居民的脑灌注。通常的步态速度在电子垫上评估超过 5.6 米。性别和 BMI 调整的线性回归模型使用连续年龄、SBP 和 ASL 之间的 3 向和 2 向交互项估计横断面步态速度与 ASL 的关联以及年龄和 SBP 的修正效应。结果报告了示例 SBP 和年龄的步态速度每标准差 (SD) 较低 ASL 的估计差异。结果 在 479 名参与者中（平均年龄 67.6 岁；44% 为女性；平均步态速度 1.17m/s），ASL 与步态速度的关系因年龄（ASL-x-年龄相互作用：p=0.001）和 SBP（ASL-x-SBP 相互作用：p=0.009）而异。在 SBP 为 120mmHg 时，每个 SD 较低的 ASL 与 65 岁时 0.04 m/s (95% CI: 0.01,0.07) 较慢的步态速度、75 岁时 0.07 m/s (0.04,0.10) 和 0.09 m 相关/s (0.05,0.13) 在 85 年。在 SBP 为 140 mmHg 时，ASL 与步态速度的关联在 65、75 和 85 岁时衰减至 0.01 (-.01,0.04)、0.04 (0.02,0.06) 和 0.06 (0.04,0.09) m/s 较慢的步态速度， 分别。结论 较差的脑灌注与具有临床意义的较慢步速相关，尤其是年龄较大的人，而较高的脑灌注显着减弱步速的年龄差异。65 岁时步速为 04 m/s（95% CI：0.01,0.07），75 岁时为 0.07 m/s（0.04,0.10），85 岁时为 0.09 m/s（0.05,0.13）。在 SBP 为 140 mmHg 时，ASL 与步态速度的关联在 65、75 和 85 岁时衰减至 0.01 (-.01,0.04)、0.04 (0.02,0.06) 和 0.06 (0.04,0.09) m/s 较慢的步态速度， 分别。结论 较差的脑灌注与具有临床意义的较慢步速相关，尤其是年龄较大的人，而较高的脑灌注显着减弱步速的年龄差异。65 岁时步速为 04 m/s（95% CI：0.01,0.07），75 岁时为 0.07 m/s（0.04,0.10），85 岁时为 0.09 m/s（0.05,0.13）。在 SBP 为 140 mmHg 时，ASL 与步态速度的关联在 65、75 和 85 岁时衰减至 0.01 (-.01,0.04)、0.04 (0.02,0.06) 和 0.06 (0.04,0.09) m/s 较慢的步态速度， 分别。结论 较差的脑灌注与具有临床意义的较慢步速相关，尤其是年龄较大的人，而较高的脑灌注显着减弱步速的年龄差异。