Intermittent HypoxiaNCT03029559
Intermittent Hypoxia and Inspiratory Threshold Loading to Enhance Inspiratory Muscle Function
A study testing Intermittent Hypoxia and Inspiratory Threshold Loading in people with Intermittent Hypoxia, run by University of Florida at 1 site in United States.
Trial summary
Rehabilitation approaches introduce a stimulus to a motor system, with the goal to enhance motor function to patients. For example, exposure to brief and intermittent episodes of mild hypoxia has shown to strengthen synaptic pathways to respiratory and skeletal muscle motor neurons. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Intermittent Hypoxia
- What is being tested?
- Intermittent Hypoxia and Inspiratory Threshold Loading
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Feb 2017to 19 Feb 2018
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Participating in three or fewer musculoskeletal strength training sessions per week at an intensity equivalent to 7-10 on the Modified Borg's scale
- Participating in three or fewer cardiovascular endurance training sessions per week at an intensity equivalent to 7-10 on the Modified Borg's scale
Who cannot join
- Diagnosis of cardiovascular disease (Hypertension, arrhythmias, coronary artery disease, congenital and valvar heart diseases)
- Diagnosis of neuromuscular disease
- Diagnosis of any neurological disease
- Presence of concurrent medical illness including infection, fractures
- Diagnosis of obstructive sleep apnea
- Diagnosis of obstructive/restrictive lung disease
Show all 17Show fewer
- Diagnosis of exercise induced asthma
- Forced expiratory volume at one second/forced vital capacity (FVC) <80% and/or FVC<80% of predicted value indicating airway obstruction
- Subjects on prednisolone therapy or selective serotonin reuptake inhibitor (SSRI) therapy will be excluded from the study.
- Diagnosis of epilepsy or history of seizures and attention deficit disorders
- Pregnancy
- Diabetes
- History of coagulation disorders
- History of chronic pain
- Body mass index(BMI)> 35kg/m2
- Subjects on prescription medicines such as beta blockers and other drugs that are prescribed in any of the exclusionary disorders listed above.
- Any other factor that in the investigators' opinions would prevent response to training or create an unsafe condition for the subject.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Intermittent Hypoxia and Inspiratory Threshold Loading as Strategies to Enhance Inspiratory Muscle Function
Rehabilitation approaches introduce a stimulus to a motor system, with the goal to enhance motor function to patients. For example, exposure to brief and intermittent episodes of mild hypoxia has shown to strengthen synaptic pathways to respiratory and skeletal muscle motor neurons. In humans with spinal cord injury, exposure to intermittent hypoxia (IH) alone or in combination with rehabilitative strategies has shown enhanced motor function. Another strategy known as inspiratory threshold loading, which involves breathing against pressure threshold loads, results in improved inspiratory muscle strength. Although there is evidence supporting the use of IH alone or in combination with other rehabilitative strategies in improving motor function in humans, the impact of exposure to IH or IH with inspiratory threshold loading on inspiratory muscle function and ventilation in humans is unknown.
Read the detailed description
Investigators will test whether exposure to IH alone and in combination with inspiratory threshold loading (ITL) will result in increased inspiratory muscle strength and ventilation.
Investigators will use a Latin square, repeated measures design which will consist of 12 subjects participating in four experimental conditions.There will be an interval of 1 week between each of the four conditions, which will serve as a washout period.
At the end of each of the 5 sessions, the subjects will rest in a reclining chair for 15 minutes while their heart rate, blood pressure, oxygen saturation and breathing are monitored. Subjects that have a blood systolic blood pressure > 140 or diastolic pressure > 90 or SPO2 < 92% will be asked to remain in the laboratory for 15 additional minutes and the vital signs will be repeated. If the blood pressure and/or peripheral capillary oxygen saturation (SPO2) remain outside of the criteria mentioned above, the subject will be instructed to seek assessment by their health provider and the incident will be reported to the Institutional Review Board. Subjects will also be asked to report any discomfort.
- Conditions
- Intermittent Hypoxia
- Being tested
- Intermittent Hypoxia, Inspiratory Threshold Loading, Sham Intermittent Hypoxia
- Keywords
- Inspiratory threshold loading
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intermittent HypoxiaOther
Also called IH
A single session of IH will last for 45 minutes and will consist of alternating phases of hypoxia(FiO2 :9%-11%) and hyperoxia (FiO2 :22%-38%).
Each hypoxic interval will last for 2 minutes whereas the hyperoxic interval lasts for 1 minute each (15, two-minute episodes of hypoxia and 15, one-minute episodes of hyperoxia).
Inspiratory Threshold LoadingOther
Also called ITL
Subjects will undergo inspiratory threshold loading using a commercially available Threshold IMT device (Power breathe®). ITL will be administered at an intensity of 80% of the individual's maximal inspiratory pressure (MIP). The subjects will be instructed to take 10 deep, forceful breaths through the threshold device followed by at least 2 minutes of rest. The process will be repeated 4 more times for a total of 5 sets of 10 breaths each.
Sham Intermittent HypoxiaOther
Also called Normoxia
Subjects will be exposed to a session of sham Intermittent hypoxia.This will consist of breathing room air for 45 minutes through a hypoxicator.
| Study group | Role | What they receive |
|---|---|---|
| IH + ITL | Experimental | Subjects will be exposed to a session of Intermittent hypoxia (IH) (45 minutes, 2 minutes of hypoxia alternating with 1 minute of hyperoxia) followed by 5 sets of Inspiratory threshold loading (ITL) at 80%MIP (10 breaths per set). Receives: Other: Intermittent Hypoxia; Other: Inspiratory Threshold Loading |
| Intermittent hypoxia (IH) | Experimental | Subjects will only be exposed to a session of intermittent hypoxia. Receives: Other: Intermittent Hypoxia |
| Sham IH + ITL | Experimental | Sham Intermittent Hypoxia + Inspiratory threshold loading (ITL) subjects will be exposed to a single 45-minute session of sham IH (normoxia). This will consist of the subject breathing room air (FiO2=21%) through a 4 way valve connected to the hypoxicator. Exposure to normoxia will be followed by 5 sets of ITL at 80%MIP (10 breaths per set). Receives: Other: Inspiratory Threshold Loading; Other: Sham Intermittent Hypoxia |
| Sham IH | Sham comparator | Sham intermittent hypoxia subjects will be exposed to a single 45-minute session of sham IH alone. Receives: Other: Sham Intermittent Hypoxia |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maximal Inspiratory Pressure will be measured across all groups
Maximal Inspiratory Pressure(MIP) which is a measure of inspiratory muscle strength will be measured as the MIP recorded at the mouth by a pressure manometer. Subjects will be seated upright in a comfortable chair and the nose occluded with clips. After exhaling to residual volume (RV), subjects place their lips around the mouthpiece and inspire as forcefully as possible for at least three seconds. Repeated measurements will be taken, with a 1- to 2-min rest between trials, until three measurements are obtained within 5% variability. Of these three values, the best MIP will be recorded.
Measured: Change between 15, 30, and 60 minutes
Ventilatory responses to inspiratory loading will be measured across all groups
Subjects will be asked to breathe as forcefully as possible against a inspiratory load( 2-4 sets of 5 repetitions) of either 40% of their maximal inspiratory pressure(MIP) or at 41CmH2O (lowest of the two as the maximum resistance offered by the device is 41CmH2O) using a inspiratory muscle training (IMT) device. During this task, a respiratory monitor will be connected to the IMT device. Parameters such as the inspiratory flow, volume and pressure generated by the subjects while breathing against the load will be recorded. Imposed work of breathing (WOBi) will be calculated as a product of the pressure generated and the inspired tidal volume when breathing against a fixed load (40%MIP).
Measured: Change between 15, 30, and 60 minutes
Mouth occlusion pressure (P0.1) will be measured across all groups
To record P0.1, the subjects will breathe through a mouth piece connected to a 2 way respiratory valve in a closed circuit. As the subjects breathe through the circuit, the inspiratory valve will be manually occluded during the expiratory phase and the occlusion will be maintained till the end of next inspiration. Occlusion will be random in order to prevent the subjects from getting conscious about the occlusions. The circuit is connected to the respiratory monitor and the negative pressure recorded in the first 100 milliseconds of the occluded breath will be recorded as the subject's P0.1.
3 such recordings will be obtained and the highest pressure amongst the 3 trials will be considered for analysis.
Measured: Change between 15, 30, and 60 minutes
Secondary outcomes (1)
Heart Rate Variability (HRV) will be measured across all groups
Heart Rate Variability (HRV): HRV will be assessed to determine the autonomic response to intermittent hypoxia. HRV will be measured using a 3 lead ECG and HRV recording kit.
Measured: Change between 15, 30, and 60 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jan 2017 (estimated)
- Study start17 Feb 2017
- Primary completion19 Feb 2018
- Study completion19 Feb 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intermittent HypoxiaStudies of the same condition, open and under way.
- More trials run by University of FloridaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Model description
- Latin square, repeated measures design to study the effects of IH administered alone and in combination with inspiratory threshold loading on the above stated respiratory parameters.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Florida
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Daniel Martin, PhD, Principal investigator, University of Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03029559
- Sponsor's protocol ID
- IRB201601878
- Status last verified
- Jun 2019
- First submitted
- 17 Jan 2017
- Last updated
- 20 Jun 2019
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Jun 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intermittent Hypoxia and Inspiratory Threshold Loading as Strategies to Enhance Inspiratory Muscle Function
- ClinicalTrials.gov ID
- NCT03029559
- Acronym / sponsor ID
- IRB201601878
- Conditions
- Intermittent Hypoxia
- Keywords
- Inspiratory threshold loading
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- University of FloridaUniversity, hospital or other
- Study start
- 17 Feb 2017 (actual)
- Primary completion
- 19 Feb 2018 (actual)
- Study completion
- 19 Feb 2018 (actual)
- First posted
- 24 Jan 2017 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Rehabilitation approaches introduce a stimulus to a motor system, with the goal to enhance motor function to patients. For example, exposure to brief and intermittent episodes of mild hypoxia has shown to strengthen synaptic pathways to respiratory and skeletal muscle motor neurons. In humans with spinal cord injury, exposure to intermittent hypoxia (IH) alone or in combination with rehabilitative strategies has shown enhanced motor function. Another strategy known as inspiratory threshold loading, which involves breathing against pressure threshold loads, results in improved inspiratory muscle strength. Although there is evidence supporting the use of IH alone or in combination with other rehabilitative strategies in improving motor function in humans, the impact of exposure to IH or IH with inspiratory threshold loading on inspiratory muscle function and ventilation in humans is unknown.
Detailed description
Investigators will test whether exposure to IH alone and in combination with inspiratory threshold loading (ITL) will result in increased inspiratory muscle strength and ventilation.
Investigators will use a Latin square, repeated measures design which will consist of 12 subjects participating in four experimental conditions.There will be an interval of 1 week between each of the four conditions, which will serve as a washout period.
At the end of each of the 5 sessions, the subjects will rest in a reclining chair for 15 minutes while their heart rate, blood pressure, oxygen saturation and breathing are monitored. Subjects that have a blood systolic blood pressure > 140 or diastolic pressure > 90 or SPO2 < 92% will be asked to remain in the laboratory for 15 additional minutes and the vital signs will be repeated. If the blood pressure and/or peripheral capillary oxygen saturation (SPO2) remain outside of the criteria mentioned above, the subject will be instructed to seek assessment by their health provider and the incident will be reported to the Institutional Review Board. Subjects will also be asked to report any discomfort.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Single blind (participant)
- Number of arms
- 4
- Model description
- Latin square, repeated measures design to study the effects of IH administered alone and in combination with inspiratory threshold loading on the above stated respiratory parameters.
| Arm | Type | Receives |
|---|---|---|
| IH + ITL | Experimental | Other: Intermittent Hypoxia, Other: Inspiratory Threshold LoadingSubjects will be exposed to a session of Intermittent hypoxia (IH) (45 minutes, 2 minutes of hypoxia alternating with 1 minute of hyperoxia) followed by 5 sets of Inspiratory threshold loading (ITL) at 80%MIP (10 breaths per set). |
| Intermittent hypoxia (IH) | Experimental | Other: Intermittent HypoxiaSubjects will only be exposed to a session of intermittent hypoxia. |
| Sham IH + ITL | Experimental | Other: Inspiratory Threshold Loading, Other: Sham Intermittent HypoxiaSham Intermittent Hypoxia + Inspiratory threshold loading (ITL) subjects will be exposed to a single 45-minute session of sham IH (normoxia). This will consist of the subject breathing room air (FiO2=21%) through a 4 way valve connected to the hypoxicator. Exposure to normoxia will be followed by 5 sets of ITL at 80%MIP (10 breaths per set). |
| Sham IH | Sham comparator | Other: Sham Intermittent HypoxiaSham intermittent hypoxia subjects will be exposed to a single 45-minute session of sham IH alone. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Participating in three or fewer musculoskeletal strength training sessions per week at an intensity equivalent to 7-10 on the Modified Borg's scale
- Participating in three or fewer cardiovascular endurance training sessions per week at an intensity equivalent to 7-10 on the Modified Borg's scale
Key exclusion criteria (17 listed)
- Diagnosis of cardiovascular disease (Hypertension, arrhythmias, coronary artery disease, congenital and valvar heart diseases)
- Diagnosis of neuromuscular disease
- Diagnosis of any neurological disease
- Presence of concurrent medical illness including infection, fractures
- Diagnosis of obstructive sleep apnea
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Intermittent HypoxiaAlso: IHA single session of IH will last for 45 minutes and will consist of alternating phases of hypoxia(FiO2 :9%-11%) and hyperoxia (FiO2 :22%-38%). Each hypoxic interval will last for 2 minutes whereas the hyperoxic interval lasts for 1 minute each (15, two-minute episodes of hypoxia and 15, one-minute episodes of hyperoxia). | Other | IH + ITL, Intermittent hypoxia (IH) |
| Inspiratory Threshold LoadingAlso: ITLSubjects will undergo inspiratory threshold loading using a commercially available Threshold IMT device (Power breathe®). ITL will be administered at an intensity of 80% of the individual's maximal inspiratory pressure (MIP). The subjects will be instructed to take 10 deep, forceful breaths through the threshold device followed by at least 2 minutes of rest. The process will be repeated 4 more times for a total of 5 sets of 10 breaths each. | Other | IH + ITL, Sham IH + ITL |
| Sham Intermittent HypoxiaAlso: NormoxiaSubjects will be exposed to a session of sham Intermittent hypoxia.This will consist of breathing room air for 45 minutes through a hypoxicator. | Other | Sham IH, Sham IH + ITL |
Primary outcome
Maximal Inspiratory Pressure will be measured across all groups
Time frame: Change between 15, 30, and 60 minutes
Maximal Inspiratory Pressure(MIP) which is a measure of inspiratory muscle strength will be measured as the MIP recorded at the mouth by a pressure manometer. Subjects will be seated upright in a comfortable chair and the nose occluded with clips. After exhaling to residual volume (RV), subjects place their lips around the mouthpiece and inspire as forcefully as possible for at least three seconds. Repeated measurements will be taken, with a 1- to 2-min rest between trials, until three measurements are obtained within 5% variability. Of these three values, the best MIP will be recorded.
Ventilatory responses to inspiratory loading will be measured across all groups
Time frame: Change between 15, 30, and 60 minutes
Subjects will be asked to breathe as forcefully as possible against a inspiratory load( 2-4 sets of 5 repetitions) of either 40% of their maximal inspiratory pressure(MIP) or at 41CmH2O (lowest of the two as the maximum resistance offered by the device is 41CmH2O) using a inspiratory muscle training (IMT) device. During this task, a respiratory monitor will be connected to the IMT device. Parameters such as the inspiratory flow, volume and pressure generated by the subjects while breathing against the load will be recorded. Imposed work of breathing (WOBi) will be calculated as a product of the pressure generated and the inspired tidal volume when breathing against a fixed load (40%MIP).
Mouth occlusion pressure (P0.1) will be measured across all groups
Time frame: Change between 15, 30, and 60 minutes
To record P0.1, the subjects will breathe through a mouth piece connected to a 2 way respiratory valve in a closed circuit. As the subjects breathe through the circuit, the inspiratory valve will be manually occluded during the expiratory phase and the occlusion will be maintained till the end of next inspiration. Occlusion will be random in order to prevent the subjects from getting conscious about the occlusions. The circuit is connected to the respiratory monitor and the negative pressure recorded in the first 100 milliseconds of the occluded breath will be recorded as the subject's P0.1. 3 such recordings will be obtained and the highest pressure amongst the 3 trials will be considered for analysis.
1 secondary outcome
Heart Rate Variability (HRV) will be measured across all groups
Time frame: Change between 15, 30, and 60 minutes
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jun 2019.
Related trials for Intermittent Hypoxia
Not yet recruiting
Acute Intermittent Hypoxia Therapy for Depression
Major Depressive Disorder (MDD)
Recruiting
Influence of Intermittent Hypoxia on Loop Gain in Healthy Subjects
Intermittent Hypoxia, Healthy Volunteers
Not yet recruiting
Safety and Efficacy of Carotid Artery Stenting Combined With Intermittent Hypoxia Intervention in Patients With Severe Internal Carotid Artery Stenosis
Internal Carotid Artery Stenosis
Recruiting
Brain Connectivity and Corticospinal Excitability in Response to Moderate Hypoxia
Normoxia, Intermittent Moderate Hypoxia
Recruiting
BioFLO for Respiratory Recovery in SCI
Spinal Cord Injuries
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Daniel Martin, PhD principal investigator
University of Florida
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Intermittent Hypoxia and Inspiratory Threshold Loading in people with Intermittent Hypoxia, run by University of Florida at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 Jun 2019. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Maximal Inspiratory Pressure will be measured across all groups (time frame: Change between 15, 30, and 60 minutes). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jun 2019.