Parkinson DiseaseNCT07674264
Cross-System Effects of Acute Intermittent Hypercapnia-Based Interventions in PD
A study testing Acute intermittent hypercapnic hypoxia (AIHH) and Acute intermittent hypercapnic normoxia (AIHN) in people with Parkinson Disease and Parkinsonism, run by University of Florida at 2 sites in United States.
Trial summary
Parkinsonism impairs upper airway and axial motor control, leading to disordered breathing, reduced speech volume, and ineffective cough. Symptoms are poorly addressed by current therapies. Read more about this study
- Who is it for?
- Ages 40 to 75 years
- Conditions the study is for
- Parkinson Disease, Parkinsonism
- What is being tested?
- Acute intermittent hypercapnic hypoxia (AIHH) and Acute intermittent hypercapnic normoxia (AIHN)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 2 sitesUnited States
- Study dates
- 12 Aug 2026to 31 Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 40 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- adults 40 to 75 years of age (the latter to reduce the likelihood of cardiovascular disease)
- diagnosis of idiopathic Parkinsonism with Hoehn and Yahr stages 2-4
- medically stable with physician clearance
- ability to ambulate at least 10 feet with/without assistance
- ability to follow directions
- willing to abstain from blood donation for the duration of the study
Who cannot join
- additional neurologic conditions
- severe illness or infection, including respiratory/cardiovascular/lung disease, or uncontrolled hypertension
- inspiratory stridor
- pregnancy due to unknown tAIH effects on a fetus, although females of childbearing age will not be excluded*
- cigarette smoking or vaping within 5 years
- history of head/neck/lung cancer with the exception of basal cell carcinoma
Show all 10Show fewer
- is currently participating in another research study that could influence the results from this study
- has deep brain stimulation electrodes implanted or has a history of deep brain stimulation
- faints or becomes lightheaded at the sight of blood
- If a female of childbearing potential indicates there is a chance she could be pregnant, she will be provided a pregnancy test and allowed to continue in the study if negative. This is because the fetal risks associated with intermittent hypoxia are unknown.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites, 2 recruiting
- Recruiting
University of Florida
Gainesville, Florida, 32610
Michela Mir, CCC-SLP, PhD, 352-273-6095, michela.mir@ufl.edu
Alysha Bogard, PhD, 3038279875, abogard@ufl.edu
- Recruiting
Norman Fixel Institute for Neurological Diseases
Gainesville, Florida, 80303-2181
Michela Mir, CCC-SLP, PhD, 303-827-9875, michela.mir@ufl.edu
Alysha Bogard, PhD, 3038279875, abogard@ufl.edu
About this study
Official title: A Pilot Study of Acute Intermittent Hypercapnia-Based Interventions on Upper Airway and Axial Motor Function in Parkinson's Disease
Parkinsonism impairs upper airway and axial motor control, leading to disordered breathing, reduced speech volume, and ineffective cough. Symptoms are poorly addressed by current therapies. This randomized pilot trial tests whether a single session of acute intermittent hypercapnic hypoxia (AIHH) or hypercapnic normoxia (AIHN) improves upper airway and axial motor function in Parkinsonism, and explores biomarker correlates of intervention responsiveness.
- Conditions
- Parkinson Disease, Parkinsonism
- Being tested
- Acute intermittent hypercapnic hypoxia (AIHH), Acute intermittent hypercapnic normoxia (AIHN)
- Keywords
- Axial function, Upper airway, Breathing, Acute Intermittent Hypercapnic Hypoxia
- Medical subject headings
- Parkinson Disease, Parkinsonian Disorders, Respiratory Aspiration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Acute intermittent hypercapnic hypoxia (AIHH)Other
Participants randomized to Group 1 will breathe brief bouts of AIHH, involving 15, 1.5-min exposures to 9-10% O2 and 4-5% CO2, alternated with 1 minute of 21% O2 (room air).
Acute intermittent hypercapnic normoxia (AIHN)Other
Participants randomized to Group 2 will breathe brief bouts of AIHN, involving 15, 1.5-min exposures to 21% O2 and 4-5% CO2, alternated with 1 minute of 21% O2 (room air).
| Study group | Role | What they receive |
|---|---|---|
| Group 1: Acute Intermittent Hypercapnic Hypoxia | Experimental | Each participant randomly allocated to this arm will breathe brief bouts of mild acute intermittent hypercapnic hypoxia as the intervention, with PRE and POST testing of upper airway, axial function, and blood-based biomarkers. Receives: Other: Acute intermittent hypercapnic hypoxia (AIHH) |
| Group 2: Acute Intermittent Hypercapnic Normoxia | Active comparator | Each participant randomly allocated to this arm will breathe brief bouts of mild acute intermittent hypercapnic normoxia as the intervention, with PRE and POST testing of upper airway, axial function, and blood-based biomarkers. Receives: Other: Acute intermittent hypercapnic normoxia (AIHN) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in speech loudness
Within-subject differences in sound pressure level (decibels) pre/post intervention and differences between intervention groups (AIHH vs. AIHN) during sustained phonation and connected speech.
Measured: baseline and 60 minutes post-intervention
Change in maximum phonation duration
Within-subject differences in duration (s) of sustained "ah" pre/post intervention and differences in duration between intervention groups (AIHH vs. AIHN).
Measured: baseline and 60-minutes post-intervention
Change in peak expiratory flow rate during voluntary cough
Within-subject differences in peak expiratory flow rate (L/s) produced during maximal volitional cough production, pre/post intervention, and between group (AIHH vs. AIHN) differences in peak expiratory flow rate.
Measured: baseline and 60 minutes post-intervention
Change in Five-Times Sit-to-Stand performance
Within-subject differences in average time (s) to complete 5 times sit-to-stand task, pre/post intervention, and differences between intervention groups (AIHH vs. AIHN).
Measured: baseline and 60 minutes post-intervention
Change in Timed Up and Go performance
Within-subject differences in duration (s) of Timed Up and Go performance, pre/post intervention. This includes duration of time participants take to stand, walk 3m, turn, walk back 3m, and sit. Differences in duration will also be compared between intervention groups (AIHH vs. AIHN).
Measured: baseline and 60 minutes post-intervention
Change in fast walking speed
Within-subject differences in duration (s) of 10M walk test, pre/post intervention. Differences in duration will also be compared between intervention groups (AIHH vs. AIHN)
Measured: baseline and 60 minutes post-intervention
Correlation between blood-based biomarkers and functional outcomes
Relationship between baseline biomarkers (APOE and BDNF genotype, inflammatory cytokines, serum urate, and circulating α-synuclein) and differences in speech loudness (dB), phonation duration (s), TUG (s), 5x sit-to-stand, and 10M walk test, pre/post intervention in both AIHH and AIHN intervention groups.
Measured: Baseline and 60 minutes post-intervention; genotype assessed at baseline only
Secondary outcomes (5)
Change in words per breath during connected speech
Within-subject differences in the total number of words produced per breath while reading aloud Grandfather Passage, pre/post intervention. Words per breath will also be measured and compared between intervention groups (AIHH vs. AIHN).
Measured: baseline and 60 minutes post-intervention
Change in cough volume acceleration during voluntary cough
Within-subject differences in cough volume acceleration (L/s²) during maximal volitional cough production, pre/post intervention, and between groups (AIHH vs. AIHN). Cough volume acceleration is calculated as peak expiratory flow divided by peak expiratory flow rise time.
Measured: Baseline and 60 minutes post-intervention
Change in airway occlusion pressure
Within-subject differences in mouth occlusion pressure (P0.1) measured in cmH2O, pre/post intervention, and between group differences (AIHH vs. AIHN). P0.1 is the pressure generated at the mouth during the first 0.1 seconds of inspiration against an occluded airway.
Measured: Baseline and 60 minutes post-intervention
Change in quiet breathing minute ventilation
Within-subject differences in minute-ventilation (L/min ), pre/post intervention, and between group differences (AIHH vs. AIHN) measured during 20 minutes of quiet breathing. Minute ventilation is the calculated using breathing frequency (breaths per minute) x tidal volume (L).
Measured: Baseline and 60 minutes post-intervention
Association between sleep characteristics and functional outcomes
Relationship between sleep-related metrics (apnea-hypopnea index, oxygen saturation index, and sleep fragmentation) and differences in speech loudness (dB), phonation duration (s), TUG (s), 5x sit-to-stand, and 10M walk test, pre/post intervention in both AIHH and AIHN intervention groups. AHI is calculated by dividing total number of apneas/hypopneas by total hours of sleep. ODI is calculated by dividing the number of times %oxygen drops below baseline by total hours of sleep.
Measured: Overnight sleep assessment between acclimation and testing visit; functional outcomes measured at baseline and 60 minutes post-intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jun 2026
- Study start12 Aug 2026
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson DiseaseStudies 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
- Parallel groups
- Model description
- Single blind, randomized parallel study design
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Florida
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Michela Mir, CCC-SLP, Principal investigator, University of FloridaAlysha Bogard, PhD, Principal investigator, University of Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07674264
- Sponsor's protocol ID
- IRB202600117
- Status last verified
- Jun 2026
- First submitted
- 16 Jun 2026
- Last updated
- 21 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data may be made available upon reasonable request following publication of the primary study results and with approval of the study investigators and University of Florida.
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Study of Acute Intermittent Hypercapnia-Based Interventions on Upper Airway and Axial Motor Function in Parkinson's Disease
- ClinicalTrials.gov ID
- NCT07674264
- Acronym / sponsor ID
- IRB202600117
- Conditions
- Parkinson Disease, Parkinsonism
- Keywords
- Axial function, Upper airway, Breathing, Acute Intermittent Hypercapnic Hypoxia
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- University of FloridaUniversity, hospital or other
- Study start
- 12 Aug 2026 (actual)
- Primary completion
- 31 Dec 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 29 Jun 2026 (actual)
- 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.
Parkinsonism impairs upper airway and axial motor control, leading to disordered breathing, reduced speech volume, and ineffective cough. Symptoms are poorly addressed by current therapies. This randomized pilot trial tests whether a single session of acute intermittent hypercapnic hypoxia (AIHH) or hypercapnic normoxia (AIHN) improves upper airway and axial motor function in Parkinsonism, and explores biomarker correlates of intervention responsiveness.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Single blind, randomized parallel study design
| Arm | Type | Receives |
|---|---|---|
| Group 1: Acute Intermittent Hypercapnic Hypoxia | Experimental | Other: Acute intermittent hypercapnic hypoxia (AIHH)Each participant randomly allocated to this arm will breathe brief bouts of mild acute intermittent hypercapnic hypoxia as the intervention, with PRE and POST testing of upper airway, axial function, and blood-based biomarkers. |
| Group 2: Acute Intermittent Hypercapnic Normoxia | Active comparator | Other: Acute intermittent hypercapnic normoxia (AIHN)Each participant randomly allocated to this arm will breathe brief bouts of mild acute intermittent hypercapnic normoxia as the intervention, with PRE and POST testing of upper airway, axial function, and blood-based biomarkers. |
Who may qualify
- Ages
- 40 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- adults 40 to 75 years of age (the latter to reduce the likelihood of cardiovascular disease)
- diagnosis of idiopathic Parkinsonism with Hoehn and Yahr stages 2-4
- medically stable with physician clearance
- ability to ambulate at least 10 feet with/without assistance
- ability to follow directions
Key exclusion criteria (10 listed)
- additional neurologic conditions
- severe illness or infection, including respiratory/cardiovascular/lung disease, or uncontrolled hypertension
- inspiratory stridor
- pregnancy due to unknown tAIH effects on a fetus, although females of childbearing age will not be excluded*
- cigarette smoking or vaping within 5 years
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 |
|---|---|---|
| Acute intermittent hypercapnic hypoxia (AIHH)Participants randomized to Group 1 will breathe brief bouts of AIHH, involving 15, 1.5-min exposures to 9-10% O2 and 4-5% CO2, alternated with 1 minute of 21% O2 (room air). | Other | Group 1: Acute Intermittent Hypercapnic Hypoxia |
| Acute intermittent hypercapnic normoxia (AIHN)Participants randomized to Group 2 will breathe brief bouts of AIHN, involving 15, 1.5-min exposures to 21% O2 and 4-5% CO2, alternated with 1 minute of 21% O2 (room air). | Other | Group 2: Acute Intermittent Hypercapnic Normoxia |
Primary outcome
Change in speech loudness
Time frame: baseline and 60 minutes post-intervention
Within-subject differences in sound pressure level (decibels) pre/post intervention and differences between intervention groups (AIHH vs. AIHN) during sustained phonation and connected speech.
Change in maximum phonation duration
Time frame: baseline and 60-minutes post-intervention
Within-subject differences in duration (s) of sustained "ah" pre/post intervention and differences in duration between intervention groups (AIHH vs. AIHN).
Change in peak expiratory flow rate during voluntary cough
Time frame: baseline and 60 minutes post-intervention
Within-subject differences in peak expiratory flow rate (L/s) produced during maximal volitional cough production, pre/post intervention, and between group (AIHH vs. AIHN) differences in peak expiratory flow rate.
Change in Five-Times Sit-to-Stand performance
Time frame: baseline and 60 minutes post-intervention
Within-subject differences in average time (s) to complete 5 times sit-to-stand task, pre/post intervention, and differences between intervention groups (AIHH vs. AIHN).
Change in Timed Up and Go performance
Time frame: baseline and 60 minutes post-intervention
Within-subject differences in duration (s) of Timed Up and Go performance, pre/post intervention. This includes duration of time participants take to stand, walk 3m, turn, walk back 3m, and sit. Differences in duration will also be compared between intervention groups (AIHH vs. AIHN).
Change in fast walking speed
Time frame: baseline and 60 minutes post-intervention
Within-subject differences in duration (s) of 10M walk test, pre/post intervention. Differences in duration will also be compared between intervention groups (AIHH vs. AIHN)
Correlation between blood-based biomarkers and functional outcomes
Time frame: Baseline and 60 minutes post-intervention; genotype assessed at baseline only
Relationship between baseline biomarkers (APOE and BDNF genotype, inflammatory cytokines, serum urate, and circulating α-synuclein) and differences in speech loudness (dB), phonation duration (s), TUG (s), 5x sit-to-stand, and 10M walk test, pre/post intervention in both AIHH and AIHN intervention groups.
5 secondary outcomes
Change in words per breath during connected speech
Time frame: baseline and 60 minutes post-intervention
Change in cough volume acceleration during voluntary cough
Time frame: Baseline and 60 minutes post-intervention
Change in airway occlusion pressure
Time frame: Baseline and 60 minutes post-intervention
Change in quiet breathing minute ventilation
Time frame: Baseline and 60 minutes post-intervention
Association between sleep characteristics and functional outcomes
Time frame: Overnight sleep assessment between acclimation and testing visit; functional outcomes measured at baseline and 60 minutes post-intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Aug 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data may be made available upon reasonable request following publication of the primary study results and with approval of the study investigators and University of Florida.
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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.
Michela Mir, CCC-SLP principal investigator
University of Florida
Alysha Bogard, PhD principal investigator
University of Florida
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Acute intermittent hypercapnic hypoxia (AIHH) and Acute intermittent hypercapnic normoxia (AIHN) in people with Parkinson Disease and Parkinsonism, run by University of Florida at 2 sites 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 6 inclusion and 10 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: looking for participants now, as of the sponsor's last update on 21 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Michlela Mir, CCC-SLP, PhD (352-273-6095, michela.mir@ufl.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in speech loudness (time frame: baseline and 60 minutes post-intervention). The study lists 7 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 21 Aug 2026.