Essential HypertensionEarly Phase 1NCT06287580
Effects of Antihypertensive Drug Treatment on Brain Blood Flow, Cognition, and Regulation of Nervous System in Older Adults With Hypertension.
A Early Phase 1 study testing chlorthalidone in people with Essential Hypertension and Older Adults, run by University of Texas Southwestern Medical Center at 1 site in United States.
Trial summary
High blood pressure (BP) is a public health problem worldwide. Nearly three-quarters of older adults (age ~60 years) in the United States have high BP. High BP links to many health problems, like stroke. Drug treatments are typically used in clinics to reduce high BP and the risk of associated health problems. Read more about this study
- Who is it for?
- Ages 60 to 85 years
- Conditions the study is for
- Essential Hypertension, Older Adults
- What is being tested?
- chlorthalidone
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 27 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Aug 2024to 20 Feb 2026
- Phase
- Early Phase 1
- 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 60 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Older men and women with prehypertension or mild-to-moderate essential hypertension (clinic systolic blood pressure 120-169 and/or diastolic blood pressure 80-109 mmHg).
Who cannot join
- Any evidence of cardiovascular or pulmonary disease by medical history or by physical examination
- Severe hypertension (systolic BP ≥170 and/or diastolic BP ≥110 mmHg; for safety reasons) or secondary hypertension
- Being on ≥3 antihypertensive agents
- Chronic kidney disease (an estimated glomerular filtration rate \>45 mL/min) or renal failure
- Diabetes mellitus (fasting glucose ≥126 mg/dL or 2-hour oral glucose tolerance test, glucose level ≥200 mg/dL) or other systemic illness
- Any history of substance abuse (other than tobacco)
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- Current cigarette smokers
- History of gouty arthritis
- Taking hormonal replacement therapy
- Endurance-trained athletes
- Diagnosed Alzheimer's disease and related dementias
Trial locations and contacts
1 site in 1 country.
United States1 site
Institute for Exercise and Environmental Medicine
Dallas, Texas, 75231
About this study
Official title: Antihypertensive Drug Effects on Cerebral Hemodynamics and Sympathetic Control in Older Hypertensive Patients
High blood pressure (BP) is a public health problem worldwide. Nearly three-quarters of older adults (age ~60 years) in the United States have high BP. High BP links to many health problems, like stroke. Drug treatments are typically used in clinics to reduce high BP and the risk of associated health problems. However, these drug treatments may not always benefit brain health. For example, drug treatment may reduce brain blood flow, which may reduce cognitive function in older adults with high BP. Alternatively, reduced brain blood flow may cause high BP due to increased nervous system activity (the so-called "fight or flight response"). Thus, monitoring brain blood flow may help to manage high BP during drug treatment.
It is unknown if brain blood flow and its control will be altered by drug treatment in older high BP patients. Therefore, study team will recruit older adults with high BP, who receive either drug treatment or a placebo for 1 to 2 weeks and will assess brain blood flow, cognitive function, and nervous system control before and after treatment.
Results from this study will provide novel and clinically relevant information on the impact of drug treatment for high BP on brain health. Investigators expect these results will suggest that it is crucial to measure brain blood flow, which may be a therapeutic new target for BP control and brain health.
- Conditions
- Essential Hypertension, Older Adults
- Being tested
- chlorthalidone, Placebo
- Keywords
- antihypertensive drug, cerebral blood flow, cognitive function
- Medical subject headings
- Essential Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
chlorthalidoneDrug
chlorthalidone, 12.5 mg or 25 mg orally once daily
PlaceboOther
Placebo tablet taken orally once daily
| Study group | Role | What they receive |
|---|---|---|
| Antihypertensive drug treatment Arm | Active comparator | Participants will take a fixed dose of chlorthalidone (a diuretic, 12.5 mg or 25 mg orally once daily) for one to two week, with study visits for laboratory assessment at before and after intervention. Receives: Drug: chlorthalidone |
| Placebo treatment Arm | Placebo comparator | Participants will receive placebo treatment for one to two weeks, with study visits for laboratory assessment at before and after intervention. Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Muscle sympathetic nerve activity (MSNA) from baseline at post intervention
Muscle sympathetic nerve activity will be measured using microneurography at the peroneal nerve. Muscle sympathetic nerve activity will be quantified by identification and measurement of sympathetic bursts in the integrated neurogram and expressed as burst frequency (mean number of bursts per unit time)
Measured: Baseline, post intervention
Change in cognitive performance from baseline at post intervention via Stroop Color and Word Test
Change in cognitive performance is measured by Stroop Color and Word Test. Accuracy and reaction time in the Stroop Color and Word test are computed to assess cognitive performance.
Measured: Baseline, post intervention
Change in Cerebral blood flow from baseline at post intervention
A probe will be placed over an artery in participant's neck and temple. Total cerebral blood flow is calculated as a sum of blood flow from the four arteries of the internal carotid artery and vertebral artery. The distribution of cardiac output to the brain is calculated as the percentage of total cerebral blood flow to cardiac output.
Measured: Baseline, post intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Mar 2024
- Study start15 Aug 2024
- Primary completion20 Feb 2026
- Study completion20 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Essential HypertensionStudies of the same condition, open and under way.
- More trials run by University of Texas Southwestern Medical CenterThe 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
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 27 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Texas Southwestern Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Takuro Washio, University of Texas Southwestern Medical Center
- Investigators
- TAKURO WASHIO, Ph.D., Principal investigator, University of Texas Southwestern Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06287580
- Sponsor's protocol ID
- STU-2024-0140
- Status last verified
- Feb 2026
- First submitted
- 23 Feb 2024
- Last updated
- 27 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Antihypertensive Drug Effects on Cerebral Hemodynamics and Sympathetic Control in Older Hypertensive Patients
- ClinicalTrials.gov ID
- NCT06287580
- Acronym / sponsor ID
- STU-2024-0140
- Conditions
- Essential Hypertension, Older Adults
- Keywords
- antihypertensive drug, cerebral blood flow, cognitive function
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 27 participants (actual)
- Lead sponsor
- University of Texas Southwestern Medical CenterUniversity, hospital or other
- Study start
- 15 Aug 2024 (actual)
- Primary completion
- 20 Feb 2026 (actual)
- Study completion
- 20 Feb 2026 (actual)
- First posted
- 1 Mar 2024 (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.
High blood pressure (BP) is a public health problem worldwide. Nearly three-quarters of older adults (age ~60 years) in the United States have high BP. High BP links to many health problems, like stroke. Drug treatments are typically used in clinics to reduce high BP and the risk of associated health problems. However, these drug treatments may not always benefit brain health. For example, drug treatment may reduce brain blood flow, which may reduce cognitive function in older adults with high BP. Alternatively, reduced brain blood flow may cause high BP due to increased nervous system activity (the so-called "fight or flight response"). Thus, monitoring brain blood flow may help to manage high BP during drug treatment.
It is unknown if brain blood flow and its control will be altered by drug treatment in older high BP patients. Therefore, study team will recruit older adults with high BP, who receive either drug treatment or a placebo for 1 to 2 weeks and will assess brain blood flow, cognitive function, and nervous system control before and after treatment.
Results from this study will provide novel and clinically relevant information on the impact of drug treatment for high BP on brain health. Investigators expect these results will suggest that it is crucial to measure brain blood flow, which may be a therapeutic new target for BP control and brain health.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Antihypertensive drug treatment Arm | Active comparator | Drug: chlorthalidoneParticipants will take a fixed dose of chlorthalidone (a diuretic, 12.5 mg or 25 mg orally once daily) for one to two week, with study visits for laboratory assessment at before and after intervention. |
| Placebo treatment Arm | Placebo comparator | Other: PlaceboParticipants will receive placebo treatment for one to two weeks, with study visits for laboratory assessment at before and after intervention. |
Who may qualify
- Ages
- 60 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Older men and women with prehypertension or mild-to-moderate essential hypertension (clinic systolic blood pressure 120-169 and/or diastolic blood pressure 80-109 mmHg).
Key exclusion criteria (11 listed)
- Any evidence of cardiovascular or pulmonary disease by medical history or by physical examination
- Severe hypertension (systolic BP ≥170 and/or diastolic BP ≥110 mmHg; for safety reasons) or secondary hypertension
- Being on ≥3 antihypertensive agents
- Chronic kidney disease (an estimated glomerular filtration rate \>45 mL/min) or renal failure
- Diabetes mellitus (fasting glucose ≥126 mg/dL or 2-hour oral glucose tolerance test, glucose level ≥200 mg/dL) or other systemic illness
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 |
|---|---|---|
| chlorthalidonechlorthalidone, 12.5 mg or 25 mg orally once daily | Drug | Antihypertensive drug treatment Arm |
| PlaceboPlacebo tablet taken orally once daily | Other | Placebo treatment Arm |
Primary outcome
Change in Muscle sympathetic nerve activity (MSNA) from baseline at post intervention
Time frame: Baseline, post intervention
Muscle sympathetic nerve activity will be measured using microneurography at the peroneal nerve. Muscle sympathetic nerve activity will be quantified by identification and measurement of sympathetic bursts in the integrated neurogram and expressed as burst frequency (mean number of bursts per unit time)
Change in cognitive performance from baseline at post intervention via Stroop Color and Word Test
Time frame: Baseline, post intervention
Change in cognitive performance is measured by Stroop Color and Word Test. Accuracy and reaction time in the Stroop Color and Word test are computed to assess cognitive performance.
Change in Cerebral blood flow from baseline at post intervention
Time frame: Baseline, post intervention
A probe will be placed over an artery in participant's neck and temple. Total cerebral blood flow is calculated as a sum of blood flow from the four arteries of the internal carotid artery and vertebral artery. The distribution of cardiac output to the brain is calculated as the percentage of total cerebral blood flow to cardiac output.
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 27 Feb 2026.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
TAKURO WASHIO, Ph.D. principal investigator
University of Texas Southwestern Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing chlorthalidone in people with Essential Hypertension and Older Adults, run by University of Texas Southwestern Medical Center 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 1 inclusion and 11 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 27 Feb 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.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
Change in Muscle sympathetic nerve activity (MSNA) from baseline at post intervention (time frame: Baseline, post intervention). 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 27 Feb 2026.