VasoActive Research Group, School of Health, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD, 4556, Australia.
Physiology and Ultrasound Laboratory in Science and Exercise, Centre for Research on Exercise, Physical Activity and Health, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD, Australia.
Eur J Appl Physiol. 2022 Aug;122(8):1843-1856. doi: 10.1007/s00421-022-04956-w. Epub 2022 May 6.
Our aim was to compare cerebrovascular and systemic vascular function between older adults with and without mild cognitive impairment (MCI), and to determine which measures of vascular function best predict the presence of MCI.
In 41 adults with MCI and 33 adults without MCI (control) we compared middle cerebral artery velocity (MCAv) and cerebrovascular pulsatility index (PI) at rest, cerebrovascular reactivity to CO, and responsiveness to changes in blood pressure (%∆MCAv/%∆MAP). Systemic vascular function was assessed by flow-mediated dilation (FMD) and stiffness by pulse wave velocity (PWV).
Cerebrovascular PI was higher in MCI compared with control (mean ± SD: 1.17 ± 0.27 vs. 1.04 ± 0.21), and MCI exhibited a lower %∆MCAv/%∆MAP (1.26 ± 0.44 vs. 1.50 ± 0.55%). Absolute (p = 0.76) and relative cerebrovascular reactivity to CO (p = 0.34) was similar between MCI and control. When age was included as a covariate the significant difference in cerebral PI between groups was lost. PWV was higher (13.2 ± 2.2 vs. 11.3 ± 2.5 m s) and FMD% (4.41 ± 1.70 vs. 5.43 ± 2.15%) was lower in MCI compared with control. FMD% was positively associated with PI across the cohort. Logistic regression analysis indicated that FMD and PWV significantly discriminated between MCI and controls, independent of age, whereas the inclusion of cerebrovascular measures did not improve the predictive accuracy of the model.
These findings raise the possibility that early changes in systemic vascular stiffness and endothelial function may contribute to altered cerebrovascular haemodynamics and impaired cognitive function, and present potential targets for prevention and treatment strategies in people with MCI.
本研究旨在比较伴有和不伴有轻度认知障碍（MCI）的老年人之间的脑血管和全身血管功能，并确定哪些血管功能指标最能预测 MCI 的存在。
在 41 名 MCI 患者和 33 名无 MCI 的对照组中，我们比较了静息状态下大脑中动脉速度（MCAv）和脑血管搏动指数（PI）、CO 反应性和血压变化的响应性（%ΔMCAv/%ΔMAP）。通过血流介导的扩张（FMD）和脉搏波速度（PWV）评估全身血管功能。
与对照组相比，MCI 患者的脑血管 PI 更高（平均值±标准差：1.17±0.27 对 1.04±0.21），且 MCI 患者的%ΔMCAv/%ΔMAP 较低（1.26±0.44 对 1.50±0.55%）。MCI 和对照组之间绝对（p=0.76）和相对 CO 脑血管反应性相似。当将年龄作为协变量纳入时，两组之间的脑 PI 显著差异消失。与对照组相比，PWV 更高（13.2±2.2 对 11.3±2.5 m/s），FMD%（4.41±1.70 对 5.43±2.15%）更低。FMD%与整个队列的 PI 呈正相关。逻辑回归分析表明，FMD 和 PWV 可显著区分 MCI 和对照组，独立于年龄，而纳入脑血管指标并不能提高模型的预测准确性。
这些发现提示，全身血管僵硬和内皮功能的早期变化可能导致脑血管血液动力学改变和认知功能受损，为 MCI 患者提供了潜在的预防和治疗策略靶点。
