Motor Plasticity, Intermittent Hypoxia and Sleep Apnea

Intermittent Hypoxia (IH), Respiratory and Motor Plasticity, and Sleep Apnea in Spinal Cord Injury (SCI)

The purpose of this study is to learn about the effect of sleep apnea and low oxygen on muscle strength and lung function in people with chronic spinal cord injury.

Study Overview

• Status: Completed
• Conditions: Sleep Apnea, Obstructive; Hypoxia; Spinal Cord Injuries
• Intervention / Treatment: Procedure: Induced Acute Intermittent Hypoxia (AIH); Device: AIH mask

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Miami, Florida, United States, 33136
      • University of Miami

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age 18 or older,
2. Chronic (≥ 1-year post-injury), non-progressive SCI,
3. Asia Impairment Scale (AIS) C or D,
4. Resting Saturated oxygen (SaO2) ≥ 95%,
5. Cervical injury (C5-C8)

Exclusion Criteria:

1. Currently hospitalized,
2. Resting heart rate ≥120 Beats per minute (BPM),
3. Resting systolic blood pressure >180 mmHg,
4. Resting diastolic Blood Pressure >100 mmHg,
5. Self-reported history of unstable angina or myocardial infarction within the previous month,
6. OSA that is being treated with positive airway pressure therapy,
7. Women who know or suspect they may be pregnant or who may become pregnant,
8. Known underlying lung disease,
9. Pregnant Women,
10. Prisoners,
11. Unable to consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Moderate to Severe Obstructive Sleep Apnea (OSA); Individuals with moderate to severe OSA defined as having an Apnea-hypopnea Index (AHI) that is greater than or equal to 15.	Procedure: Induced Acute Intermittent Hypoxia (AIH); AIH will be administered on days 1-3. Each day entails 15 and 90 second hypoxic intervals (Fraction of Inspired Oxygen (FIO2) = 0.09) alternating with 60-second normoxic intervals (FIO2 = 0.21).; Device: AIH mask; Induced Intermitted hypoxia will be delivered via the AIH mask. The mask has two one-way valves restricting inspiration to the top valve and expiration to the bottom valve. Hypoxic and normoxic gas mixtures will be delivered through the top valve.
Active Comparator: Without OSA; Individuals without OSA defined as having AHI less than 5.	Procedure: Induced Acute Intermittent Hypoxia (AIH); AIH will be administered on days 1-3. Each day entails 15 and 90 second hypoxic intervals (Fraction of Inspired Oxygen (FIO2) = 0.09) alternating with 60-second normoxic intervals (FIO2 = 0.21).; Device: AIH mask; Induced Intermitted hypoxia will be delivered via the AIH mask. The mask has two one-way valves restricting inspiration to the top valve and expiration to the bottom valve. Hypoxic and normoxic gas mixtures will be delivered through the top valve.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The difference in Motor Function assessed via hand grip strength measured by maximum grip strength (MGS) between participants with moderate to severe OSA and without OSA.	Participants will be instructed to squeeze the hand grip dynamometer with maximal effort for 3-5 seconds. This will be repeated three times for each hand with 1 minute of rest between trials. The highest value obtained will be used as the MGS.	Baseline
The difference in Motor Function assessed via hand grip strength measured by electromyographic (EMG) recordings between participants with moderate to severe OSA and without OSA.	Electrodes will be secured on the participant to measure EMG. Participants will then be asked to press the index finger against a custom lever. The participant will perform three brief maximal voluntary contractions (MVC) for 3-5 seconds separated by 60 seconds of rest. The highest of the three values will be used.	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Motor Function assessed via hand grip strength measured by MGS.	Participants will be instructed to squeeze the hand grip dynamometer with maximal effort for 3-5 seconds. This will be repeated three times for each hand with 1 minute of rest between trials. The highest value obtained will be used as the MGS.	Baseline to Day 1 post AIH, Baseline to Day 3 post AIH, Baseline to Day 10, Baseline to Day 17
Change in Motor Function assessed via hand grip strength measured by EMG recordings.	Electrodes will be secured on the participant to measure EMG. Participants will then be asked to press the index finger against a custom lever. The participant will perform three brief maximal voluntary contractions (MVC) for 3-5 seconds separated by 60 seconds of rest. The highest of the three values will be used.	Baseline to Day 1 post AIH, Baseline to Day 3 post AIH, Baseline to Day 10, Baseline to Day 17
Change in biomarker levels	Serum Brain-Derived Neurotrophic Factor (BDNF) and Vascular Endothelial Growth Factor (VEGF) biomarker levels in pg/ml will be evaluated. At baseline, the blood samples will be collected after 12 hours of overnight fasting.	Baseline to Day 1 post AIH, Baseline to Day 3 post AIH, Baseline to Day 10, Baseline to Day 17

Collaborators and Investigators

• Sponsor: University of Miami
• Collaborators: The Craig H. Neilsen Foundation
• Investigators: Principal Investigator: Shirin Shafazand, MD, University of Miami

Study record dates

Study Major Dates

• Study Start (Actual): July 16, 2021
• Primary Completion (Actual): July 1, 2025
• Study Completion (Actual): July 1, 2025

Study Registration Dates

• First Submitted: July 9, 2019
• First Submitted That Met QC Criteria: July 9, 2019
• First Posted (Actual): July 12, 2019

Study Record Updates

• Last Update Posted (Estimated): September 8, 2025
• Last Update Submitted That Met QC Criteria: September 4, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Neuroplasticity; Motor Function; Respiratory Function
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Pathologic Processes; Respiratory Tract Diseases; Respiration Disorders; Sleep Wake Disorders; Signs and Symptoms, Respiratory; Apnea; Sleep Disorders, Intrinsic; Dyssomnias; Trauma, Nervous System; Sleep Apnea Syndromes; Spinal Cord Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Respiratory Aspiration; Hypoxia; Sleep Apnea, Obstructive; Spinal Cord Injuries
• Other Study ID Numbers: 20190415

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