Low Oxygen Therapy as a Cardiac Treatment for Improving 24-hour Blood Pressure Stability in Spinal Cord Injury
试验速览
- 阶段
- 1 期
- 状态
- 招募中
- 发起方
- 入组人数
- 10
- 试验地点
- 2
- 主要终点
- Change in 24-hour blood pressure
研究概览
简要总结
This study examines the effects of low oxygen therapy (LOT) on the stability of 24-hour blood pressure in persons with chronic cervical spinal cord injury.
This study will examine if brief episodes of breathing lower oxygen, termed low oxygen therapy (LOT), which has been shown to enhance autonomic nervous system activity, can improve blood pressure stability in individuals with spinal cord injury. The research team will assess 24-hour blood pressure, as well as cardiac, vascular, and autonomic function before and after a 4-day LOT treatment intervention. This study will advance current understanding of treatments to mitigate cardiovascular disease risk in people with spinal cord injuries.
详细描述
Spinal cord injury (SCI) interrupts signals travelling down from the brain to the rest of the body below the level of the injury. The loss of nerve connections involved in cardiovascular control results in blood pressure instability. This can lead to sudden drops in blood pressure, such as when shifting upright or during transfers, or sudden increases during autonomic dysreflexia. These swings in blood pressure are linked to a nearly 4-fold increase in the risk of cardiovascular disease in people with SCI.
Repeated, brief exposure to breathing lower levels of oxygen, termed low oxygen therapy, has been shown to stimulate adaptation in the nervous system. This neuroplasticity increases the activity of cardiovascular control circuits, and has been shown to increase blood pressure in able-bodied individuals. Similar effects on respiratory and motor function in people with SCI, but the effects on the cardiovascular system have not been studied in this population.
This study will test the effects of a 4-day low oxygen therapy intervention on 24-hour blood pressure stability in people with chronic cervical SCI. By assessing mechanisms of cardiac, vascular, and autonomic function, this study aims to improve current understanding of the therapeutic potential of low oxygen therapy to mitigate cardiovascular disease risk in SCI.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 19 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Are between the ages of 19-65
- •Living with a chronic cervical (at or above T1) spinal cord injury of at least one year
- •Are fluent in english
排除标准
- •High-cervical injuries requiring ventilator assistance to breathe will be excluded on account of the necessity of the facemask for the delivery of hypoxia
- •Unhealed fracture, contracture, or pressure sore that might interfere with participants' ability to complete the protocol
- •Additional concurrent neurological conditions (e.g., multiple sclerosis, Parkinson disease, stroke or brain injury)
- •Uncontrolled cardiovascular or pulmonary disease
- •Severe neuropathic pain
- •Severe recurrent autonomic dysreflexia
- •History of seizure disorders
- •Known pregnancy
研究组 & 干预措施
Room air control; lot oxygen therapy; recovery/washout
Participants with chronic cervical spinal cord injury will undergo a 4-day low oxygen therapy intervention.
Measurements will first be taken at least three days before the beginning of the intervention to establish baseline characteristics, immediately before and after the first day of the intervention to assess the acute response to the intervention, and on the first and fourth days after the end of the intervention to assess persistent effects and washout.
干预措施: Low oxygen therapy (LOT) (Drug)
结局指标
主要结局
Change in 24-hour blood pressure
时间窗: Change from baseline of 24-hour mean arterial blood pressure at 1-day post-intervention
Mean arterial blood pressure (mmHg), averaged across 24 hours
次要结局
- Change in 24-hour blood pressure stability(Change from baseline of the standard deviation of 24-hour mean arterial blood pressure at 1-day post-intervention)
- Change in left-ventricular contractility(Change from baseline of left ventricular contractility indices immediately after the first intervention session, and at 1-day and 4-days post-intervention)
- Change in baroreflex gain(Change from baseline of baroreflex gain indices immediately after first intervention session, and at 1-day and 4-days post-intervention)
- Change in circulating catecholamines(Change from baseline of circulating catecholamines immediately after first intervention session, and at 1-day and 4-days post-intervention)
- Change in cerebral neurovascular coupling and autoregulation(Change from baseline of the responses of cerebral blood flow indices during a visual stimulus and head-up tilt immediately after first intervention session, and at 1-day and 4-days post-intervention)
- Change in renal filtration function(Change from baseline in renal biomarkers and blood flow at rest immediately after first intervention session, and at 1-day and 4-days post-intervention)
- Change in flow-mediated dilation(Change from baseline in flow-mediated dilation immediately after first intervention session, and at 1-day and 4-days post-intervention)
- Change in tonic peripheral chemoreflex activity(Change from baseline in the magnitude of ventilatory depression in hyperoxia immediately after first intervention session, and at 1-day and 4-days post-intervention)
- Change in renal vascular function(Change in renal blood flow velocity from baseline during the first and final hypoxia cycles on the first session of the intervention)
研究者
Glen Foster
Professor
University of British Columbia