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

NCT ID: NCT06691165

Last Updated: 2025-11-18

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-10-23
• Study Completion Date: 2026-12-31

Brief Summary

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.

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.

Conditions

Spinal Cord Injury

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

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.

Group Type: EXPERIMENTAL

Low oxygen therapy (LOT)

Intervention Type: DRUG

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.

Interventions

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.

Intervention Type: DRUG

Other Intervention Names

Intermittent hypoxia

Eligibility Criteria

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

• Minimum Eligible Age: 19 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Glen Foster

OTHER

Sponsor Role: lead

Responsible Party

Glen Foster

Professor

Responsibility Role: SPONSOR_INVESTIGATOR

Locations

UBC Okanagan

Kelowna, British Columbia, Canada

Site Status: RECRUITING

International Collaboration on Repair Discoveries (ICORD)

Vancouver, British Columbia, Canada

Site Status: RECRUITING

Countries

Canada

Central Contacts

Scott F Thrall, M.Sc.

Role: CONTACT

sthrall@student.ubc.ca

+1 250-807-8083

Glen E Foster, Ph.D.

Role: CONTACT

glen.foster@ubc.ca

+1 250-807-8224

Facility Contacts

Scott Thrall, MSc

Role: primary

sthrall@student.ubc.ca

2508078083

Glen Foster, PhD

Role: backup

glen.foster@ubc.ca

250-807-8224

Scott Thrall, MSc

Role: primary

sthrall@student.ubc.ca

2508078083

Glen Foster, PhD

Role: backup

glen.foster@ubc.ca

250-807-8224

References

Vermeulen TD, Benbaruj J, Brown CV, Shafer BM, Floras JS, Foster GE. Peripheral chemoreflex contribution to ventilatory long-term facilitation induced by acute intermittent hypercapnic hypoxia in males and females. J Physiol. 2020 Oct;598(20):4713-4730. doi: 10.1113/JP280458. Epub 2020 Aug 19.

Reference Type: BACKGROUND

PMID: 32744340 (View on PubMed)

Claydon VE, Steeves JD, Krassioukov A. Orthostatic hypotension following spinal cord injury: understanding clinical pathophysiology. Spinal Cord. 2006 Jun;44(6):341-51. doi: 10.1038/sj.sc.3101855. Epub 2005 Nov 22.

Reference Type: BACKGROUND

PMID: 16304564 (View on PubMed)

Vose AK, Welch JF, Nair J, Dale EA, Fox EJ, Muir GD, Trumbower RD, Mitchell GS. Therapeutic acute intermittent hypoxia: A translational roadmap for spinal cord injury and neuromuscular disease. Exp Neurol. 2022 Jan;347:113891. doi: 10.1016/j.expneurol.2021.113891. Epub 2021 Oct 9.

Reference Type: BACKGROUND

PMID: 34637802 (View on PubMed)

Perim RR, Vinit S, Mitchell GS. Cervical spinal hemisection effects on spinal tissue oxygenation and long-term facilitation of phrenic, renal and splanchnic sympathetic nerve activity. Exp Neurol. 2023 Oct;368:114478. doi: 10.1016/j.expneurol.2023.114478. Epub 2023 Jul 13.

Reference Type: BACKGROUND

PMID: 37451584 (View on PubMed)

Welch JF, Vose AK, Cavka K, Brunetti G, DeMark LA, Snyder H, Wauneka CN, Tonuzi G, Nair J, Mitchell GS, Fox EJ. Cardiorespiratory Responses to Acute Intermittent Hypoxia in Humans With Chronic Spinal Cord Injury. J Neurotrauma. 2024 Sep;41(17-18):2114-2124. doi: 10.1089/neu.2023.0353. Epub 2024 Apr 18.

Reference Type: BACKGROUND

PMID: 38468543 (View on PubMed)

Other Identifiers

F23-01237

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

H24-02648

Identifier Type: -

Identifier Source: org_study_id