Essential Hypertension, Older Adults
Conditions
Keywords
antihypertensive drug, cerebral blood flow, cognitive function
Brief 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. 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.
Interventions
DRUGchlorthalidone
chlorthalidone, 12.5 mg or 25 mg orally once daily
OTHERPlacebo
Placebo tablet taken orally once daily
Sponsors
University of Texas Southwestern Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
60 Years to 85 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Muscle sympathetic nerve activity (MSNA) from baseline at post intervention | 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 | 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 | 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. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORTAKURO WASHIO, Ph.D.
University of Texas Southwestern Medical Center
Outcome results
None listed