CEREBRAL VASOREGULATION IN DIABETES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 本研究的目的是评估伴有直立性低血压的糖尿病自主神经病变对脑血管调节的影响，并确定糖尿病无症状性脑血管病变的指示因素。···为了量化糖尿病自主神经病变对脑血管调节的影响，一项对比实验研究将使用经颅多普勒超声在有和没有OH的非随机糖尿病患者和40名非糖尿病对照组中评估脑动脉的血管运动反应性。在低碳酸血症、高碳酸血症、仰卧位和血压快速变化时，将通过经颅多普勒测量血流速度来测量脑血管调节。有效的血管调节范围将被确定，以确定在立位应激期间，如果血管调节失效或血压下降到自动调节范围以下，可能存在低灌流风险的OH患者。将使用动脉自旋标记以及T2加权FLAIR在3特斯拉的MRI来确定和量化糖尿病自主神经病变中白质变化的分布，其中OH指示静息性低灌流。根据倾斜期间血压下降的脑血管调节指数和临床因素，将开发出区分MRI上与OH相关的WMC与非特定年龄相关变化的模型。从完成研究的受试者那里获得的数据将根据协议进行分析。这项研究可能具有潜在的临床影响，并可能有助于确定老年糖尿病患者中风的风险人群。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this study is to assess the impact of diabetic autonomic neuropathy with orthostatic hypotension (OH) on cerebral vasoregulation and determine the factors indicative of silent cerebrovascular disease in diabetes. OH is the most severe feature of autonomic neuropathy and increases the risk for stroke. To quantify the effects of diabetic autonomic neuropathy with OH on cerebral vasoregulation, a comparative experimental study will evaluate vasomotor reactivity of cerebral arteries using transcranial Doppler (TCD) ultrasonography in non-randomized diabetic patients with and without OH and 40 non-diabetic controls. Cerebral vasoregulation will be measured from blood flow velocities measured by TCD during hypo- and hypercapnia, tilt-up and rapid blood pressure changes. The range of effective vasoregulation will be determined to identity the OH patients who might be at risk for hypoperfusion during orthostatic stress if vasoregulation fails or blood pressure declines below autoregulated range. An arterial spin labeling (ASL) will be used, as well as a T2 weighted (FLAIR) MRI at 3 Tesla to determine and quantify the distribution of white matter changes (WMC) in diabetic autonomic neuropathy with OH indicative of silent hypoperfusion. Models will be developed distinguishing OH-associated WMC on MRI from non-specific age-related changes, based on indices of cerebral vasoregulation adjusting for blood pressure decline during tilt and clinical factors. Data obtained from subjects who complete the study will be analyzed per protocol. This study may have potential clinical impact and it may help to identify the population of elderly diabetic patients at risk for stroke.