Objectives Arterial elasticity and physical fitness are 2 important cardiovascular health factors that influence cognition in older adults. Working memory capacity (WMC), a core component underlying cognitive aging across many cognitive domains, may be affected by individual differences in cardiovascular health in older adults. This study aims to identify in older adults: (a) separate and combined effects of these 2 cardiovascular health factors on WMC and (b) which of the 2 factors is more critical in influencing WMC. Methods WMC in 89 healthy older adults was assessed by 2 complex span tasks. Arterial elasticity was assessed by pulse pressure (PsP). Physical fitness was measured by an established proxy of VO2 max (MET). Effects of PsP and MET on WMC were evaluated via step-wise regressions. Results After controlling for age, sex, and education, PsP and MET were separately predictive of WMC in older adults. Together, the combined effect of PsP and MET was more predictive of WMC than fitness alone, but not more than PsP alone. Mediation analysis indicates that the relationship between MET and WMC was completely mediated by PsP. Discussion This study innovatively demonstrates that though arterial elasticity and physical fitness separately predict WMC, the former completely mediates the relationship between fitness and WMC. This suggests that biologically based cardiovascular health factors like arterial elasticity are crucial individual difference variables that should be measured and monitored in cognitive aging studies as well as in physical interventions that are designed to improve cognition in healthy aging.

中文翻译：

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比较两种心血管健康因素对健康老龄化过程中工作记忆能力的影响：动脉弹性和体能的单独和综合影响


目标 动脉弹性和身体健康是影响老年人认知的两个重要心血管健康因素。工作记忆能力（WMC）是许多认知领域认知衰老的核心组成部分，可能会受到老年人心血管健康个体差异的影响。本研究旨在确定老年人：(a) 这 2 个心血管健康因素对 WMC 的单独和综合影响，以及 (b) 这 2 个因素中哪一个对影响 WMC 更为关键。方法 通过 2 个复杂的跨度任务评估 89 名健康老年人的 WMC。通过脉压（PsP）评估动脉弹性。身体健康通过最大摄氧量 (MET) 的既定指标来衡量。通过逐步回归评估 PsP 和 MET 对 WMC 的影响。结果在控制年龄、性别和教育程度后，PsP 和 MET 分别预测老年人的 WMC。总之，PsP 和 MET 的联合作用比单独的健身更能预测 WMC，但并不比单独的 PsP 更强。中介分析表明MET和WMC之间的关系完全由PsP介导。讨论 本研究创新性地证明，虽然动脉弹性和体能分别预测 WMC，但前者完全调节体能和 WMC 之间的关系。这表明基于生物学的心血管健康因素（如动脉弹性）是至关重要的个体差异变量，应在认知衰老研究以及旨在改善健康衰老认知的物理干预中进行测量和监测。