NCT02323698

Effects of Caffeine and Intermittent Hypoxia on Leg Function in Human Spinal Cord Injury

The Effects of Intermittent Hypoxia on Leg Function in Human Spinal Cord Injury (Caffeine Substudy)

• Status: Completed
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 36 (actual)
• Sponsor: Spaulding Rehabilitation Hospital · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

Accumulating evidence suggests that repeatedly breathing low oxygen levels for brief periods (termed intermittent hypoxia) is a safe and effective treatment strategy to promote meaningful functional recovery in persons with chronic spinal cord injury (SCI). The goal of the study is to understand how caffeine may augment the effects of intermittent hypoxia on motor function and spinal plasticity (ability of the nervous system to strengthen neural pathways based on new experiences) following SCI.

Detailed description

The investigators will examine the effects of acute intermittent hypoxia (AIH) as a possible therapeutic intervention to promote functionally useful motor recovery. In this sub-study, the investigators will assess changes in leg motor function in response to repetitive AIH with and without caffeine. Participants will receive caffeine+AIH, placebo+AIH, caffeine+SHAM in a randomized order. Before each intervention round, subjects will be asked to avoid caffeine-containing substances for 48 hrs (\> 5\* half-life of \~7 hrs) prior to arrival to control for baseline plasma levels of caffeine. Subjects will then ingest capsules containing either placebo (dextrose) or caffeine (up to 6mg/kg). Capsules will be prepared by Johnson Compounding \& Wellness. Blood samples will be collected before and after the breathing intervention to assess caffeine concentrations within the body. During and after each intervention, both the rate and extent of magnitude changes in voluntary and involuntary muscle response behaviors important for walking will be compared between interventions within participants. Repeated measurements will be collected on all subjects that participate in the multiple interventions.

Conditions

• Spinal Cord Injuries

Interventions

Type	Name	Description
DRUG	Caffeine	Subjects will ingest capsules containing caffeine (up to 6mg/kg). Experiments will begin 30min after consumption to approximately coincide with peak plasma concentrations.Throughout the 30min wait time and experimentation, blood pressure and heart rate will be monitored.
OTHER	AIH	Participants will breathe intermittent low oxygen via air generators. The generators will fill reservoir bags attached to a non-rebreathing face mask. Oxygen concentration will be continuously monitored to ensure delivery of FIO2 (fraction of inspired oxygen) = 0.10±0.02 (hypoxia). Throughout experimentation, blood pressure and heart rate will be monitored.
OTHER	Placebo	This is a placebo counterpart to the caffeine drug. Subjects will ingest capsules containing dextrose. Experiments will begin 30min after consumption to mimic the caffeine drug protocol. Throughout experimentation, blood oxygenation, blood pressure and heart rate will be monitored.
OTHER	SHAM	This is a placebo counterpart to breathing intermittent low oxygen. Participants will breathe intermittent room air via air generators. The generators will fill reservoir bags attached to a non-rebreathing face mask. Oxygen concentration will be continuously monitored to ensure delivery of FIO2 (fraction of inspired oxygen) = 0.21±0.02 (normoxia). Throughout experimentation, blood pressure and heart rate will be monitored.

Timeline

• Start date: 2019-01-01
• Primary completion: 2021-03-19
• Completion: 2022-02-19
• First posted: 2014-12-23
• Last updated: 2023-12-13
• Results posted: 2022-08-09

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study