NCT07173543 · Darren P Casey
IH, Brain Health, and T2D
What this study is about
The purpose of this study is to use a randomly assigned, compared against an inactive treatment 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).
View original scientific description
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).
Interventions
OTHER
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 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
SHAM - normoxia
Participants will receive normoxia (no hypoxia) over 50 minutes.
Primary outcome measures
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
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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
Exclusion criteria
- 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
- obstructive sleep apnea
- pulmonary disease
- 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. Inclusion criteria:
- 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 Exclusion criteria:
- 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
- renal impairment with creatinine clearance (eGFR) of \<60 ml/min
- smoking or history of smoking within past one year
Where
- Iowa City, Iowa
Collaborators
American Diabetes Association
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 13, 2026 · Source of record for eligibility and locations