BLOOD PRESSURE, COGNITIVE FUNCTION & MRI IN OLDER ADULTS

目前的建议是对135名老年男性和女性的纵向研究，他们最初是在几年前进行的研究。初步数据显示，在血压相对较低的55-79岁健康个体中，24小时动态血压和心率(水平和变异性)与磁共振成像(MRI)评估的认知测试和轻微脑损伤迹象显著相关。这项后续研究的主要目标是展示动态血压技术如何有助于预测未来大脑和认知功能的变化，这些变化可能与明显的临床问题有关，但早于中风和其他脑血管病变。我们将观察两个完整的24小时期间的血压、心率水平和变异性，重点是清醒和睡眠期间的变异性和变异性，以及从清醒到睡眠的跌倒数量。为了确定已经发生的变化，将重复许多程序，包括全面的体检、临时的血压和心率测量，以及神经心理测试(抽样检查)，如记忆、注意力、抽象推理和认知灵活性等关键领域。根据MRI数据，我们将确定局灶性(T2高信号病变)和非局灶性(萎缩性)脑改变。根据我们目前的发现，我们预计，随着时间的推移，那些临时和动态血压较高、血压变异性较大、睡眠期间血压和心率下降较小的人可能会出现神经心理测试表现的下降，T2高信号和脑萎缩的增加。血压水平正常的健康老年个体可能存在认知缺陷和脑损伤的风险，这一事实对于决定老年人治疗适当的血压水平和变异性具有明显的意义。此外，未来的研究还需要集中在药物和行为方法上，这些方法除了降低临时血压外，还可以降低血压的变异性，并保持24小时的血压控制。

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.