Trial Outcomes & Findings for Improving Human Cerebrovascular Function Using Acute Intermittent Hypoxia (NCT NCT05164705)
NCT ID: NCT05164705
Last Updated: 2026-07-20
Results Overview
Phase-contrast MRI and Arterial Spin Labeling MRI will be used to quantify whole-brain and cortical gray matter perfusion (ml/100g/min) before and after the 3-week intervention.
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
33 participants
Primary outcome timeframe
4 weeks
Results posted on
2026-07-20
Participant Flow
All subjects underwent a practice session, prior to assignment, to ensure they were comfortable with the study procedures and intervention. Individuals could opt out of or be excluded from further participation at this time. 8 participants chose to opt out after the practice session, hence why they are included in the Protocol Enrollment but not in the Participants Assigned.
Participant milestones
| Measure |
Starting With True Intervention
Participant will visit our center 2-4 times per week for three weeks to receive Acute Intermittent Hypoxia.
They will then visit our center 2-4 times per week for three weeks to receive sham Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
Sham: Following the same protocol, the gas mixture will remain 21% O2.
|
Starting With Sham Intervention
Participant will visit our center 2-4 times per week for three weeks to receive sham Acute Intermittent Hypoxia.
They will then visit our center 2-4 times per week for three weeks to receive true Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
Sham: Following the same protocol, the gas mixture will remain 21% O2.
|
|---|---|---|
|
Overall Study
Completion of Arm 1
|
8
|
13
|
|
Overall Study
Completion of Arm 2
|
8
|
10
|
|
Overall Study
STARTED
|
11
|
14
|
|
Overall Study
Completion of MRI 1
|
10
|
13
|
|
Overall Study
COMPLETED
|
8
|
10
|
|
Overall Study
NOT COMPLETED
|
3
|
4
|
Reasons for withdrawal
| Measure |
Starting With True Intervention
Participant will visit our center 2-4 times per week for three weeks to receive Acute Intermittent Hypoxia.
They will then visit our center 2-4 times per week for three weeks to receive sham Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
Sham: Following the same protocol, the gas mixture will remain 21% O2.
|
Starting With Sham Intervention
Participant will visit our center 2-4 times per week for three weeks to receive sham Acute Intermittent Hypoxia.
They will then visit our center 2-4 times per week for three weeks to receive true Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
Sham: Following the same protocol, the gas mixture will remain 21% O2.
|
|---|---|---|
|
Overall Study
Adverse Event
|
1
|
1
|
|
Overall Study
Physician Decision
|
0
|
1
|
|
Overall Study
Withdrawal by Subject
|
1
|
2
|
|
Overall Study
Reached Stopping Criteria
|
1
|
0
|
Baseline Characteristics
Improving Human Cerebrovascular Function Using Acute Intermittent Hypoxia
Baseline characteristics by cohort
| Measure |
Starting With True Intervention
n=11 Participants
Participant will visit our center 2-4 times per week for three weeks to receive Acute Intermittent Hypoxia.
They will then visit our center 2-4 times per week for three weeks to receive sham Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
Sham: Following the same protocol, the gas mixture will remain 21% O2.
|
Starting With Sham Intervention
n=14 Participants
Participant will visit our center 2-4 times per week for three weeks to receive sham Acute Intermittent Hypoxia.
They will then visit our center 2-4 times per week for three weeks to receive true Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
Sham: Following the same protocol, the gas mixture will remain 21% O2.
|
Total
n=25 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Race (NIH/OMB)
White
|
6 Participants
n=20 Participants
|
7 Participants
n=20 Participants
|
13 Participants
n=40 Participants
|
|
Age, Categorical
<=18 years
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
11 Participants
n=20 Participants
|
14 Participants
n=20 Participants
|
25 Participants
n=40 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Age, Continuous
|
28.1 years
STANDARD_DEVIATION 5.9 • n=20 Participants
|
29.8 years
STANDARD_DEVIATION 8.1 • n=20 Participants
|
29.0 years
STANDARD_DEVIATION 7.2 • n=40 Participants
|
|
Sex: Female, Male
Female
|
4 Participants
n=20 Participants
|
5 Participants
n=20 Participants
|
9 Participants
n=40 Participants
|
|
Sex: Female, Male
Male
|
7 Participants
n=20 Participants
|
9 Participants
n=20 Participants
|
16 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
2 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
2 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
9 Participants
n=20 Participants
|
13 Participants
n=20 Participants
|
22 Participants
n=40 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=20 Participants
|
1 Participants
n=20 Participants
|
1 Participants
n=40 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Asian
|
4 Participants
n=20 Participants
|
6 Participants
n=20 Participants
|
10 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=20 Participants
|
1 Participants
n=20 Participants
|
1 Participants
n=40 Participants
|
|
Race (NIH/OMB)
More than one race
|
1 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
1 Participants
n=40 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=20 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=40 Participants
|
PRIMARY outcome
Timeframe: 4 weeksPhase-contrast MRI and Arterial Spin Labeling MRI will be used to quantify whole-brain and cortical gray matter perfusion (ml/100g/min) before and after the 3-week intervention.
Outcome measures
| Measure |
Intermittent Hypoxia
n=18 Participants
Participant will visit our center 2-4 times per week for three weeks to receive Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
|
Sham Intermittent Hypoxia
n=21 Participants
Participants will visit our center 2-4 times per week for three weeks to receive Sham Intermittent Hypoxia.
Sham Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and breathe normal air (21 percent O2) for 30-minutes.
|
|---|---|---|
|
Resting Cerebral Blood Flow
|
.5 change in CBF (ml/100g/min)
Standard Deviation 10.6
|
-2.4 change in CBF (ml/100g/min)
Standard Deviation 7.9
|
SECONDARY outcome
Timeframe: 4 weeksPhase-contrast MRI and Arterial Spin Labeling MRI will be used to quantify the change in perfusion caused by a vasodilatory gas challenge (inhaled hypoxia or hypercapnia), before and after the 3-week intervention.
Outcome measures
| Measure |
Intermittent Hypoxia
n=18 Participants
Participant will visit our center 2-4 times per week for three weeks to receive Acute Intermittent Hypoxia.
Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
|
Sham Intermittent Hypoxia
n=21 Participants
Participants will visit our center 2-4 times per week for three weeks to receive Sham Intermittent Hypoxia.
Sham Acute Intermittent Hypoxia: Participants will wear a non-rebreathing face mask and breathe normal air (21 percent O2) for 30-minutes.
|
|---|---|---|
|
Cerebrovascular Reactivity
|
-.01 change in CVR ((ml/100g/min)/mmHg)O2
Standard Deviation .26
|
-.03 change in CVR ((ml/100g/min)/mmHg)O2
Standard Deviation .22
|
Adverse Events
Acute Intermittent Hypoxia
Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths
Sham Acute Intermittent Hypoxia
Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Acute Intermittent Hypoxia
n=25 participants at risk
Participants will wear a non-rebreathing face mask and alternate between breathing 9% O2 gas mixture for up to 1 minute, or until the target SpO2 of 85 percent is reached, and normal room air (21 percent O2) until 2 minutes are complete. This cycle will be repeated 15 times, resulting in a 30-minute protocol.
|
Sham Acute Intermittent Hypoxia
n=25 participants at risk
Participants will wear a non-rebreathing face mask and breathe normal room air for 30 minutes
|
|---|---|---|
|
Psychiatric disorders
Anxiety Episode
|
4.0%
1/25 • Number of events 1 • During participation in trial (approximately 5-7 months)
|
0.00%
0/25 • During participation in trial (approximately 5-7 months)
|
|
Nervous system disorders
Akathisia
|
0.00%
0/25 • During participation in trial (approximately 5-7 months)
|
4.0%
1/25 • Number of events 1 • During participation in trial (approximately 5-7 months)
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place