Signaling Mechanisms and Vascular Function in Patients With Diabetes Mellitus
2008年9月29日 更新者:Brigham and Women's Hospital
The purpose of the study is to learn how blood vessel function is altered by diabetes.
We are studying an investigational drug, Ebselen, to see if it can improve the ability of blood vessels to relax (widen).
研究概览
详细说明
A major cause of death and disability in patients with diabetes mellitus is atherosclerosis.
Endothelial dysfunction is an important, if not primary, factor in atherogenesis.
Nitric oxide is an important substance made and released by the endothelium.
Many prior studies in animals and humans have shown that the ability of the blood vessel to dilate is impaired in diabetes.
This process of vasodilation is mediated by a substance, nitric oxide, which is thought to be highly susceptible to destruction by oxidant molecules.
In previous studies, we found that acute administration of the antioxidant, vitamin C, improves endothelium-dependent vasodilation in blood vessels of patients with type 1 and type 2 diabetes.
This suggests that by scavenging oxidants, such as superoxide, vitamin C may reduce the destruction of nitric oxide and thereby preserve endothelial function.
Additional mechanisms, including activation of a substance called protein kinase C, and oxidant stress from excess soluble peroxides may be present in diabetes and interact with oxidant stress to cause endothelial dysfunction in patients with diabetes.
Accordingly, we would like to study both of these mechanisms to determine their contribution to endothelial dysfunction.
研究类型
介入性
注册 (实际的)
60
阶段
- 阶段2
- 第三阶段
联系人和位置
本节提供了进行研究的人员的详细联系信息,以及有关进行该研究的地点的信息。
学习地点
-
-
Massachusetts
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Boston、Massachusetts、美国、02115
- Brigham and Women's Hosptial
-
-
参与标准
研究人员寻找符合特定描述的人,称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。
资格标准
适合学习的年龄
18年 至 85年 (成人、年长者)
接受健康志愿者
不
有资格学习的性别
全部
描述
Inclusion Criteria:
- Subjects with diabetes mellitus will be eligible if they are receiving dietary treatment for hyperglycemia, sulfonylureas, metformin or insulin
Exclusion Criteria:
- Any diabetic subject with a HgbA1C level of <7% or >11%
- Evidence of atherosclerosis
- symptoms of angina
- symptoms of claudication
- symptoms of cerebrovascular ischemia
- findings of arterial occlusive disease, as would be suggested by decreased pulses, asymmetric blood pressure, bruits or reduced limb pressure measurements
- hypertension defined as a systolic blood pressure > = 150 mmHg and a diastolic blood pressure >= 95 mmHg; (allowable blood pressure medications for diabetic subjects include calcium channel blockers, alpha and beta adrenergic blockers, and diuretics)
- hypercholesterolemia, defined as total cholesterol levels greater than 75th percentile for age and sex and LDL cholesterol levels >130mg/dL.
- renal insufficiency (serum creatinine >1.5 mg/dL for men; >1.2 mg/dL for women)
- hepatic dysfunction defined as liver enzyme abnormalities > two times the upper limit of normal
- chronic pulmonary disease
- congestive heart failure
- pregnancy (or subjects planning to become pregnant);
- history of cigarette smoking within the last five years;
history of clinically significant coronary artery or cerebrovascular disease (defined as MI or stroke within 6 months, or presence of unstable angina)
- use of any, vasoactive, cardioactive, or non-steroidal anti-inflammatory medications within 24 hours of vascular testing visits
学习计划
本节提供研究计划的详细信息,包括研究的设计方式和研究的衡量标准。
研究是如何设计的?
设计细节
- 主要用途:基础科学
- 分配:随机化
- 介入模型:交叉作业
- 屏蔽:四人间
武器和干预
参与者组/臂 |
干预/治疗 |
|---|---|
|
安慰剂比较:2个
安慰剂
|
Placebo 1 po BID for 2 weeks
|
|
有源比较器:1
Ebselen
|
150 mg BID for 2 weeks
|
研究衡量的是什么?
主要结果指标
结果测量 |
大体时间 |
|---|---|
|
Endothelium-dependent and endothelium-independent vasodilation of peripheral resistance and conduit vessels will be studied in diabetic (type 1 and 2) and healthy subjects two weeks following randomization to the ebselen or placebo.
大体时间:one testing visit every 4 weeks
|
one testing visit every 4 weeks
|
合作者和调查者
在这里您可以找到参与这项研究的人员和组织。
调查人员
- 首席研究员:Mark A Creager, MD、Brigham and Women's Hosptial
出版物和有用的链接
负责输入研究信息的人员自愿提供这些出版物。这些可能与研究有关。
研究记录日期
这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查,以确保它们在发布到公共网站之前符合特定的质量控制标准。
研究主要日期
学习开始
1999年5月1日
初级完成 (实际的)
2007年10月1日
研究完成 (实际的)
2007年10月1日
研究注册日期
首次提交
2008年9月26日
首先提交符合 QC 标准的
2008年9月29日
首次发布 (估计)
2008年9月30日
研究记录更新
最后更新发布 (估计)
2008年9月30日
上次提交的符合 QC 标准的更新
2008年9月29日
最后验证
2008年9月1日
更多信息
此信息直接从 clinicaltrials.gov 网站检索,没有任何更改。如果您有任何更改、删除或更新研究详细信息的请求,请联系 register@clinicaltrials.gov. clinicaltrials.gov 上实施更改,我们的网站上也会自动更新.