Improving 24-hour Blood Pressure Stability in Spinal Cord Injury With Low Oxygen Therapy

November 14, 2025 updated by: Glen Foster

Low Oxygen Therapy as a Cardiac Treatment for Improving 24-hour Blood Pressure Stability in Spinal Cord Injury

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.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Interventional

Enrollment (Estimated)

10

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Canada
    • British Columbia
      • Kelowna, British Columbia, Canada, V1V 1V7
        • Recruiting
        • UBC Okanagan
        • Contact:
        • Contact:
        • Principal Investigator:
          • Glen Foster, PhD
      • Vancouver, British Columbia, Canada, V5Z 1N1
        • Recruiting
        • International Collaboration on Repair Discoveries (ICORD)
        • Contact:
        • Contact:
        • Principal Investigator:
          • Glen Foster, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 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.
Drug: Low oxygen therapy (LOT)

Participants will breathe variable concentrations of inspired oxygen, carbon dioxide, and nitrogen. The concentrations will be adjusted on a breath-by-breath basis to maintain end-tidal targets.

Each daily session of the intervention will consist of forty 1-minute intervals. Each 1-minute interval will consist of 40 seconds of hypercapnic hypoxia, increasing the partial pressure of end-tidal carbon dioxide by +4 mmHg and decreasing the partial pressure of end-tidal oxygen to 45 mmHg, followed by 20 seconds in simulated room air to return to baseline carbon dioxide and oxygen levels.

Other Names:
  • Intermittent hypoxia

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in 24-hour blood pressure
Time Frame: Change from baseline of 24-hour mean arterial blood pressure at 1-day post-intervention
Mean arterial blood pressure (mmHg), averaged across 24 hours
Change from baseline of 24-hour mean arterial blood pressure at 1-day post-intervention

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in 24-hour blood pressure stability
Time Frame: Change from baseline of the standard deviation of 24-hour mean arterial blood pressure at 1-day post-intervention
Mean arterial blood pressure (mmHg), standard deviation across 24 hours
Change from baseline of the standard deviation of 24-hour mean arterial blood pressure at 1-day post-intervention
Change in left-ventricular contractility
Time Frame: Change from baseline of left ventricular contractility indices immediately after the first intervention session, and at 1-day and 4-days post-intervention
Indices of load-independent pressure generation during systole: Estimated end-systolic elastance (mmHg/ml); end-systolic pressure-volume relationship slopes (mmHg/ml)
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
Time Frame: Change from baseline of baroreflex gain indices immediately after first intervention session, and at 1-day and 4-days post-intervention
Indices of baroreflex sensitivity: Relationship of systolic blood pressure against subsequent R-R interval duration during Valsalva Maneuver phases II and IV (ms/mmHg); spectral power of low-frequency resting blood pressure variability
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
Time Frame: Change from baseline of circulating catecholamines immediately after first intervention session, and at 1-day and 4-days post-intervention
Venous plasma concentrations of norepinephrine and epinephrine (mmol/L)
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
Time Frame: 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
Middle and posterior cerebral artery blood flow velocity (cm/s)
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
Time Frame: 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
Humoral renal biomarkers (e.g., serum creatinine)
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
Time Frame: Change from baseline in flow-mediated dilation immediately after first intervention session, and at 1-day and 4-days post-intervention
Brachial artery flow-mediated dilation following 5-minute forearm blood flow occlusion (mm)
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
Time Frame: 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
Magnitude of hyperoxic ventilatory depression (L/min)
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
Time Frame: Change in renal blood flow velocity from baseline during the first and final hypoxia cycles on the first session of the intervention
Renal artery blood flow velocity (cm/s)
Change in renal blood flow velocity from baseline during the first and final hypoxia cycles on the first session of the intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Glen Foster

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 23, 2025

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

October 23, 2024

First Submitted That Met QC Criteria

November 13, 2024

First Posted (Actual)

November 15, 2024

Study Record Updates

Last Update Posted (Actual)

November 18, 2025

Last Update Submitted That Met QC Criteria

November 14, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • H24-02648
  • F23-01237 (Other Grant/Funding Number: Canadian Institutes of Health Research)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Spinal Cord Injury

Clinical Trials on Low oxygen therapy (LOT)

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Cambodia

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe