Cerebrovascular Responses to Acute Hypoperfusion
试验速览
- 阶段
- 2 期
- 状态
- 招募中
- 入组人数
- 36
- 试验地点
- 2
- 主要终点
- Change in blood flow
研究概览
简要总结
Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging.
详细描述
Global cerebral blood flow (CBF) decreases with advancing age; however, some adults have accelerated declines in CBF, placing them at a greater risk of cognitive impairment. However, there is a lack of human studies that investigate the cause or consequence of altered blood flow regulation in the brain. This study will systematically address this gap in knowledge by examining cerebrovascular control in adults during acute physiological challenges (simulated postural change test and breathing increased carbon dioxide) that stimulate a change in CBF.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 55 Years 至 69 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Between the ages of 55-69 years
- •Have a BMI less than or equal to 34.5 kg/m2
- •Nonsmoker
- •are less than 72 in (182.88 cm) height
- •Females must be postmenopausal
排除标准
- •Diagnosis of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD)
- •History or evidence of hepatic disease, hematological disease, or peripheral vascular disease; severe kidney injury requiring hemodialysis
- •History of cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia
- •Uncontrolled hypertension
- •History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease
- •Severe untreated obstructive sleep apnea
- •History of diabetes with HbA1c greater than 9.5%
- •Major neurologic disorders other than dementia (e.g., MS, ALS, brain surgery, etc.)
- •Current or recent (<1 year) major psychiatric condition (Axis I) or addictive disorders
- •Significant surgical history
- •Other significant medical conditions at investigators' discretion
- •Contraindications to MRI
- •Prescribed medications that interfere with prazosin
- •Lactose allergy
- •lower body will not fit in lower body negative pressure (LBNP) chamber (regardless of overall height and BMI).
研究组 & 干预措施
Middle-Aged Adults
Middle-Aged Adults between 55-69 years of age.
干预措施: Placebo (Drug)
Middle-Aged Adults
Middle-Aged Adults between 55-69 years of age.
干预措施: MRI (Device)
Middle-Aged Adults
Middle-Aged Adults between 55-69 years of age.
干预措施: Prazosin (Drug)
结局指标
主要结局
Change in blood flow
时间窗: Two study visits, up to 240 minutes
The change in intracranial blood flow during breathing and simulated postural change tasks will be measured with MRI
Change in blood velocity
时间窗: Two study visits, up to 240 minutes
The change in blood velocity during breathing and simulated postural change tasks will be measured with MRI.
次要结局
未报告次要终点