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Completed

NCT Number: NCT06287580

Effects of Antihypertensive Drug Treatment on Brain Blood Flow, Cognition, and Regulation of Nervous System in Older Adults With Hypertension.

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.

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Key information

Conditions

Essential Hypertension Cardiovascular Diseases Hypertension Older Adults Vascular Diseases

Age range

60 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

Institute for Exercise and Environmental Medicine

Dallas, Texas, 75231, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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).

Exclusion criteria

  • 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)
  • Current cigarette smokers
  • History of gouty arthritis
  • Taking hormonal replacement therapy
  • Endurance-trained athletes
  • Diagnosed Alzheimer's disease and related dementias

Treatment and study plan

Chlorthalidone

Drug

chlorthalidone, 12.5 mg or 25 mg orally once daily

Placebo

Other

Placebo tablet taken orally once daily

Primary outcomes

  1. 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)

  2. 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.

  3. 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.

Sponsors and collaborators

Lead sponsor

University of Texas Southwestern Medical Center

Other

Registry information

Official study title

Antihypertensive Drug Effects on Cerebral Hemodynamics and Sympathetic Control in Older Hypertensive Patients

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Mar 1, 2024
Registry last updated
Feb 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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