BLOOD PRESSURE, COGNITIVE FUNCTION & MRI IN OLDER ADULTS

目前的建议是对135名老年男性和女性进行纵向研究，他们在几年前首次接受研究。初步数据表明，在55-79岁、血压相对较低的健康个体中，24小时动态血压和心率（水平和变异性）与认知测试和磁共振成像（MRI）评估的细微脑损伤迹象显著相关。这项随访研究的主要目的是证明动态血压技术在预测大脑和认知功能的未来变化方面是如何有用的，这些变化可能与明显的临床问题有关，但在中风和其他脑血管病理之前。我们会观察两个24小时内的血压和心率水平和变异性，重点关注清醒和睡眠期间的变异性和水平，以及从清醒到睡眠的下降量。为了确定已经发生的变化，许多程序将被重复，包括完整的医学检查，随意的血压和心率测量，以及神经心理学测试（对记忆、注意力、抽象推理和认知灵活性等关键领域进行抽样）。根据MRI数据，我们将确定局灶性（T2高强度病变）和非局灶性（萎缩）脑改变。根据我们目前的研究结果，我们预计随着时间的推移，那些具有较高的随意血压和动态血压、较大的血压变异性、睡眠期间血压和心率下降较小的个体，可能会在神经心理测试中表现出下降，T2高信号增加和脑萎缩。血压正常的健康老年人可能有认知缺陷和脑损伤的风险，这一事实对老年人治疗血压的适当水平和可变性的决策有明确的影响。此外，未来的研究需要集中在药物和行为方法上，以减少血压的变异性，并保持24小时血压控制，除了降低随意血压。

The present proposal is a longitudinal study of 135 elderly men and women who were first studied years earlier. The initial data indicated that among healthy individuals, aged 55-79 years, with relatively low blood pressures, 24-hour ambulatory blood pressure and heart rate (both level and variability) were significantly related to cognitive tests and signs of subtle brain damage as assessed by magnetic resonance imaging (MRI). The primary goal of this follow-up study is to demonstrate how ambulatory blood pressure technology can be useful in predicting future changes in brain and cognitive function which may be associated with apparent clinical problems but predate stroke and other cerebrovascular pathology. We will look at blood pressure and heart rate level and variability during two entire 24-hour periods, focusing on variability and level during wake and sleep, and the amount of fall from wake to sleep. In order to determine changes that have occurred, many procedures will be repeated, including a complete medical exam, casual blood pressure and heart rate measurement, and neuropsychological testing (sampling such critical areas as memory, attention, abstract reasoning, and cognitive flexibility. From MRI data we will determine both focal (T2 hyperintense lesions) and non focal (atrophic) brain changes. On the basis of our current findings, we expect that with the passage of time those individuals with higher casual and ambulatory blood pressure, greater blood pressure variability, and a smaller drop in blood pressure and heart rate during sleep will be likely to exhibit decrements in neuropsychological test performance and increases in T2 hyperintensities and brain atrophy. The fact that healthy, elderly individuals with normotensive blood pressure levels may be at risk for cognitive deficits and brain damage has clear implications for decisions regarding the appropriate level and variability of blood pressure to treat in elderly. Also, there is a need for future studies to concentrate on drug and behavioral methods which decrease variability of blood pressure and maintain 24-hour blood pressure control, in addition to decreasing casual blood pressure.