Type 2 DiabetesNCT07173543
IH, Brain Health, and T2D
A study testing Intermittent Hypoxia 1 (IH1) and Intermittent Hypoxia 2 (IH2) in people with Type 2 Diabetes and Aging, run by Darren P Casey at 1 site in United States.
Trial summary
The purpose of this study is to use a randomized, placebo-controlled study design to rigorously examine the therapeutic potential of intermittent hypoxia (IH) for improving cerebrovascular health in older adults with and without type 2 diabetes mellitus (T2DM). Read more about this study
- Who is it for?
- Ages 60 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Type 2 Diabetes, Aging
- What is being tested?
- Intermittent Hypoxia 1 (IH1) and Intermittent Hypoxia 2 (IH2)
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 80 participants
- Where
- 1 siteUnited States
- Study dates
- 22 Sep 2025to 30 Jun 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 60 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures.
- Age is > or = 60 and < or = 85 years of age
- Documented Type 2 diabetes
- Scoring 26 or higher on the MoCA test
- Willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures.
- Age is > or = 60 and < or = 85 years of age
- Scoring 26 or higher on the MoCA test
Who cannot join
- diagnosis of type 2 diabetes < 1 year prior to enrollment
- HbA1c <6.5% or >10.0%
- body mass index > 40 kg/m 2
- incident cardiovascular events in the last year (heart attack, stroke)
- symptomatic coronary artery disease and/or heart failure
- uncontrolled hypertension
Show all 22Show fewer
- obstructive sleep apnea
- pulmonary disease
- dementia
- renal impairment with creatinine clearance (eGFR) of <60 ml/min
- smoking or history of smoking within past one year
- 30 nondiabetic control subjects will also be studied.
- Diagnosis of diabetes (Type 1 or Type 2)
- body mass index > 40 kg/m2
- incident cardiovascular events in the last year (heart attack, stroke)
- symptomatic coronary artery disease and/or heart failure
- uncontrolled hypertension
- obstructive sleep apnea
- pulmonary disease
- dementia
- renal impairment with creatinine clearance (eGFR) of <60 ml/min
- smoking or history of smoking within past one year
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Iowa
Iowa City, Iowa, 52242
Darren P Casey, PhD
About this study
Official title: Intermittent Hypoxia Training and Cerebrovascular Health in Older Adults With Type 2 Diabetes
The purpose of this study is to use a randomized, placebo-controlled study design to rigorously examine the therapeutic potential of intermittent hypoxia (IH) for improving cerebrovascular health in older adults with and without type 2 diabetes mellitus (T2DM).
Read the detailed description
Aging is considered a major risk factor for the development of various cardio- and cerebrovascular related diseases, with vascular endothelial dysfunction representing one of the earliest vascular complications. Age-related cerebrovascular endothelial dysfunction contributes to a progressive decrease in cerebral blood flow, which is associated with lower measures of cognitive function, including information-processing speed, executive function, and global cognition in older adults. Similar to aging, type 2 diabetes mellitus (T2DM) also negatively impacts vascular endothelial function. There is a large body of evidence that clearly demonstrates there is an interplay between aging and T2DM and that the presence of both risk factors together promotes greater endothelial dysfunction than that of either condition alone. In this context, certain measures of cerebral blood flow are reduced to a greater extent in older individuals with T2DM compared to those without. Moreover, the exaggerated cerebral perfusion deficits frequently observed among older adults with T2DM are linked to cognitive decrements. To this point, the rate of cognitive decline due to aging is increased 1.5 to 2.0-fold in individuals with T2DM. Taken together, older adults with T2DM are at greater risk for developing dementia and Alzheimer's disease when compared age-matched controls.
Exploration of non-pharmacological therapies for the improvement of cerebrovascular health and cognition have become more common over the past decade. Intermittent hypoxia (IH) is a therapeutic intervention that combines multiple, brief (~1-10 minutes) episodes of moderate hypoxia, interspersed with episodes of normoxia. In preclinical and human studies, repeated bouts of IH improve measures of respiratory, autonomic, cardio-, and cerebrovascular health. The investigators previously demonstrated that cerebral blood flow is increased with each episode of hypoxia and a single session of IH improves nitic oxide (NO) mediated endothelial function in the internal carotid artery (ICA; major supplier of overall brain blood flow) of young adults. While cerebral blood flow is also augmented during a single session of IH in older adults, the magnitude of change appears to be less, which might suggest older adults with and without T2DM may need repeated sessions of IH for improvements in cerebrovascular health to occur. The investigator's central hypothesis is that experimental use of IH will effectively and progressively improve cerebrovascular health and cognition in older adults with T2DM. Specifically, the investigators will evaluate the interplay between aging and T2DM and how it influences cerebral endothelial function as well as the cerebrovascular responses to IH (Aim 1) and test the effectiveness of IH training for the improvement of cerebrovascular health in older adults living with diabetes (Aim 2). Collectively, the proposed studies will provide 1) novel understanding of cerebrovascular function in older adults with and without T2DM, and 2) important insight into the therapeutic potential of IH for improving cerebrovascular health and cognition in older adults living with T2DM.
- Conditions
- Type 2 Diabetes, Aging
- Being tested
- Intermittent Hypoxia 1 (IH1), Intermittent Hypoxia 2 (IH2), SHAM - normoxia
- Medical subject headings
- Diabetes Mellitus, Type 2
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intermittent Hypoxia 1 (IH1)Other
Intermittent Hypoxia 1 (IH1): 5 cycles of normoxia (4 minutes)/hypoxia (6 minutes) per session. 3 sessions per week for 8 weeks
Intermittent Hypoxia 2 (IH2)Other
Intermittent Hypoxia 1 (IH2): 5 cycles of normoxia (4 minutes)/hypoxia (6 minutes) per session. 3 sessions per week for 4 weeks
SHAM - normoxiaOther
Participants will receive normoxia (no hypoxia) over 50 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Intermittent Hypoxia 1 | Experimental | Participants will receive intermittent hypoxia (5 cycles of normoxia/hypoxia over 50 minutes). Receives: Other: Intermittent Hypoxia 1 (IH1) |
| Normoxia | Sham comparator | Participants will receive normoxia over 50 minutes. Receives: Other: SHAM - normoxia |
| Intermittent Hypoxia 2 | Experimental | Participants will receive intermittent hypoxia (5 cycles of normoxia/hypoxia over 50 minutes). Receives: Other: Intermittent Hypoxia 2 (IH2) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Internal Carotid Artery (ICA) shear-mediated dilation
ICA dilation (% change) will be determined using Doppler ultrasound in response to acute hypercapnia.
Measured: Baseline and post 2-,4-,5-,6-, and 8-weeks
Cerebral blood flow responsiveness
Cerebral blood flow will be determined using Doppler ultrasound in response to acute hypoxia.
Measured: Baseline and after 50 minutes of IH or SHAM
Cognitive function testing
Working memory will be assessed using a facial recognition n-back task test
Measured: Baseline and post 4- and 8-weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Sep 2025
- Study start22 Sep 2025
- Primary completion30 Jun 2028 (estimated)
- Study completion30 Jun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Type 2 DiabetesStudies of the same condition, open and under way.
- 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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Darren P Casey
- Sponsor type
- University, hospital or other
- Collaborators
- American Diabetes Association
- Responsible party
- Sponsor-investigator, Darren P Casey, University of Iowa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07173543
- Sponsor's protocol ID
- 202505661
- Status last verified
- Mar 2026
- First submitted
- 2 Sep 2025
- Last updated
- 13 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intermittent Hypoxia Training and Cerebrovascular Health in Older Adults With Type 2 Diabetes
- ClinicalTrials.gov ID
- NCT07173543
- Acronym / sponsor ID
- 202505661
- Conditions
- Type 2 Diabetes, Aging
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Darren P CaseyUniversity, hospital or other
- Collaborators
- American Diabetes Association
- Study start
- 22 Sep 2025 (actual)
- Primary completion
- 30 Jun 2028 (estimated)
- Study completion
- 30 Jun 2028 (estimated)
- First posted
- 15 Sep 2025 (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.
The purpose of this study is to use a randomized, placebo-controlled study design to rigorously examine the therapeutic potential of intermittent hypoxia (IH) for improving cerebrovascular health in older adults with and without type 2 diabetes mellitus (T2DM).
Detailed description
Aging is considered a major risk factor for the development of various cardio- and cerebrovascular related diseases, with vascular endothelial dysfunction representing one of the earliest vascular complications. Age-related cerebrovascular endothelial dysfunction contributes to a progressive decrease in cerebral blood flow, which is associated with lower measures of cognitive function, including information-processing speed, executive function, and global cognition in older adults. Similar to aging, type 2 diabetes mellitus (T2DM) also negatively impacts vascular endothelial function. There is a large body of evidence that clearly demonstrates there is an interplay between aging and T2DM and that the presence of both risk factors together promotes greater endothelial dysfunction than that of either condition alone. In this context, certain measures of cerebral blood flow are reduced to a greater extent in older individuals with T2DM compared to those without. Moreover, the exaggerated cerebral perfusion deficits frequently observed among older adults with T2DM are linked to cognitive decrements. To this point, the rate of cognitive decline due to aging is increased 1.5 to 2.0-fold in individuals with T2DM. Taken together, older adults with T2DM are at greater risk for developing dementia and Alzheimer's disease when compared age-matched controls.
Exploration of non-pharmacological therapies for the improvement of cerebrovascular health and cognition have become more common over the past decade. Intermittent hypoxia (IH) is a therapeutic intervention that combines multiple, brief (~1-10 minutes) episodes of moderate hypoxia, interspersed with episodes of normoxia. In preclinical and human studies, repeated bouts of IH improve measures of respiratory, autonomic, cardio-, and cerebrovascular health. The investigators previously demonstrated that cerebral blood flow is increased with each episode of hypoxia and a single session of IH improves nitic oxide (NO) mediated endothelial function in the internal carotid artery (ICA; major supplier of overall brain blood flow) of young adults. While cerebral blood flow is also augmented during a single session of IH in older adults, the magnitude of change appears to be less, which might suggest older adults with and without T2DM may need repeated sessions of IH for improvements in cerebrovascular health to occur. The investigator's central hypothesis is that experimental use of IH will effectively and progressively improve cerebrovascular health and cognition in older adults with T2DM. Specifically, the investigators will evaluate the interplay between aging and T2DM and how it influences cerebral endothelial function as well as the cerebrovascular responses to IH (Aim 1) and test the effectiveness of IH training for the improvement of cerebrovascular health in older adults living with diabetes (Aim 2). Collectively, the proposed studies will provide 1) novel understanding of cerebrovascular function in older adults with and without T2DM, and 2) important insight into the therapeutic potential of IH for improving cerebrovascular health and cognition in older adults living with T2DM.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Intermittent Hypoxia 1 | Experimental | Other: Intermittent Hypoxia 1 (IH1)Participants will receive intermittent hypoxia (5 cycles of normoxia/hypoxia over 50 minutes). |
| Normoxia | Sham comparator | Other: SHAM - normoxiaParticipants will receive normoxia over 50 minutes. |
| Intermittent Hypoxia 2 | Experimental | Other: Intermittent Hypoxia 2 (IH2)Participants will receive intermittent hypoxia (5 cycles of normoxia/hypoxia over 50 minutes). |
Who may qualify
- Ages
- 60 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures.
- Age is > or = 60 and < or = 85 years of age
- Documented Type 2 diabetes
- Scoring 26 or higher on the MoCA test
- Willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures.
Key exclusion criteria (22 listed)
- diagnosis of type 2 diabetes < 1 year prior to enrollment
- HbA1c <6.5% or >10.0%
- body mass index > 40 kg/m 2
- incident cardiovascular events in the last year (heart attack, stroke)
- symptomatic coronary artery disease and/or heart failure
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 Hypoxia 1 (IH1)Intermittent Hypoxia 1 (IH1): 5 cycles of normoxia (4 minutes)/hypoxia (6 minutes) per session. 3 sessions per week for 8 weeks | Other | Intermittent Hypoxia 1 |
| Intermittent Hypoxia 2 (IH2)Intermittent Hypoxia 1 (IH2): 5 cycles of normoxia (4 minutes)/hypoxia (6 minutes) per session. 3 sessions per week for 4 weeks | Other | Intermittent Hypoxia 2 |
| SHAM - normoxiaParticipants will receive normoxia (no hypoxia) over 50 minutes. | Other | Normoxia |
Primary outcome
Internal Carotid Artery (ICA) shear-mediated dilation
Time frame: Baseline and post 2-,4-,5-,6-, and 8-weeks
ICA dilation (% change) will be determined using Doppler ultrasound in response to acute hypercapnia.
Cerebral blood flow responsiveness
Time frame: Baseline and after 50 minutes of IH or SHAM
Cerebral blood flow will be determined using Doppler ultrasound in response to acute hypoxia.
Cognitive function testing
Time frame: Baseline and post 4- and 8-weeks
Working memory will be assessed using a facial recognition n-back task test
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 13 Mar 2026.
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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.
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 1 (IH1) and Intermittent Hypoxia 2 (IH2) in people with Type 2 Diabetes and Aging, run by Darren P Casey 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 7 inclusion and 22 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 13 Mar 2026. 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?
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 Darren Casey, PHD (13193841009, darren-casey@uiowa.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Internal Carotid Artery (ICA) shear-mediated dilation (time frame: Baseline and post 2-,4-,5-,6-, and 8-weeks). 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 13 Mar 2026.