Arterial stiffness, blood pressure and cognition

我们的总体研究假设是，随着年龄的增长，动脉硬化在高血压（BP）和认知能力下降之间的关系中起着越来越重要的作用，是认知能力下降的独立危险因素。主动脉脉波速度（aPWV）及相关指标（增强指数）是衡量动脉僵硬度的可靠有效指标。我们建议召回900名参与肱血压和认知表现纵向研究的个体，进行一项有关动脉僵硬与认知表现的新研究。我们还将介绍新的中央主动脉和颈动脉血压测量，并将它们与认知功能联系起来。目前所有有关血压与认知能力的研究都采用传统的压力袖带法来评估肱动脉的血压（外周血压评估）。我们将介绍压平眼压技术。这将使我们能够检查aPWV和认知功能之间的关系，以及“更接近大脑”的动脉（主动脉和颈动脉）血压估计和认知功能。我们的主要假设是：(1)aPWV将是认知表现的独立预测因子；(2)老年人的aPWV对认知能力的影响大于年轻人；(3)特定部位血压变量与认知功能之间的关联程度排序如下：从高到低，颈动脉血压>主动脉血压>肱血压；(4)在这些压力中，收缩压的差异大于舒张压，年轻人的差异大于老年人。尽管对混淆BP和认知表现之间关系以及可能混淆aPWV和认知表现之间关系的变量进行了统计调整，但假设的关系仍然成立。作为这些新研究的辅助益处，我们将继续进行一项为期29年的肱动脉血压与认知能力的纵向研究，从而使我们能够检查肱动脉血压与年龄变化之间的线性和非线性关系。

Our overall study hypothesis is that arterial stiffness plays an increasingly important role in the relationship between high blood pressure (BP) and lowered cognitive performance with advancing age and is an independent risk factor for lowered cognitive performance. Aortic pulse wave velocity (aPWV) and related measures (Augmentation Index) are reliable and valid indices of arterial stiffness. We propose to call back 900 individuals participating in longitudinal studies of brachial BP and cognitive performance for a new study relating arterial stiffness to cognitive performance. We will also introduce new central aortic and carotid BP measures and relate them to cognitive functioning. All of the current investigations relating BP to cognitive performance have employed the traditional pressure-cuff method of assessing BP at the brachial artery (a peripheral BP assessment). We will introduce applanation tonometry technology. This will allow us to examine relations between aPWV and cognitive functioning, as well as "closer to the brain" arterial (aortic and carotid) BP estimates and cognitive functioning. Among our major hypotheses are: (1) aPWV will be an independent predictor of cognitive performance; (2) aPWV will exhibit a greater magnitude of association with cognitive performance for older than for younger persons; (3) magnitude of associations between the site-specific BP variables and cognitive functioning will be ordered as follows, highest to lowest, carotid BP> aortic BP> brachial BP; (4) greater differences among these pressures will be observed for systolic than diastolic pressure and for younger than older adults. The hypothesized relations will hold despite statistical adjustment for variables which confound relations between BP and cognitive performance and may confound relations between aPWV and cognitive performance. As an ancillary benefit of these new studies, we will continue a 29-year longitudinal study relating brachial artery BP to cognitive performance, thus allowing us to examine both linear and non-linear relations between brachial BP and changes in performance with age.