Arterial stiffness, blood pressure and cognition

我们的总体研究假设是，动脉僵硬在高血压(BP)和认知能力下降之间的关系中发挥着越来越重要的作用，并是认知能力下降的独立危险因素。主动脉脉搏波速度(APWV)及相关指标(增强指数)是反映动脉僵硬的可靠、有效的指标。我们建议召回900名参与臂部血压和认知表现纵向研究的人，以进行一项新的研究，将动脉僵硬与认知表现联系起来。我们还将介绍新的中央动脉和颈动脉血压测量方法，并将它们与认知功能联系起来。目前所有将血压与认知表现联系起来的研究都采用了传统的压力袖带法来评估臂动脉的血压(外周血压评估)。我们将介绍平压眼压测量技术。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之间的关系。我们的主要假设是：(1)aPWV将是认知表现的独立预测因子；(2)aPWV与认知表现的相关性在老年人比年轻人更大；(3)特定部位的BP变量与认知功能之间的相关性大小顺序如下：颈动脉BP和GT；主动脉BP和GT；臂BP；(4)这些压力之间的差异在收缩压比舒张压和年轻人比老年人大。尽管对变量进行了统计调整，但假设的关系仍然成立，这些变量混淆了BP和认知绩效之间的关系，并可能混淆了aPWV和认知绩效之间的关系。作为这些新研究的一个附带好处，我们将继续一项长达29年的纵向研究，将臂动脉血压与认知能力联系起来，从而使我们能够检查臂动脉血压与随年龄变化的表现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.