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Neural Control of Kidney Blood Flow During Exercise in African American Adults

Not Applicable
Recruiting
Conditions
Healthy
Registration Number
NCT03981640
Lead Sponsor
University of Massachusetts, Boston
Brief Summary

The goal of this clinical trials is to learn if healthy young African American (AA) adults have a larger change in their kidney blood flow during exercise compared to White (W) adults. The main questions that this study aims to answer are:

* Do healthy young AA adults have a larger decrease in kidney blood flow during exercise compared to W adults?

* Do healthy young AA adults have a larger decrease in kidney blood flow during other types of stress compared to W adults?

During two visits in the research lab, participants will:

* Perform a fitness test

* Perform cycling exercise while lying down

* Undergo a cold hand test

* Perform a mental math test

Completing this clinical trial will help researchers to understand more about why many AA adults have heart and kidney problems, so future research can study ways to reduce the number of AA adults who have these health issues.

Detailed Description

African American (AA) adults have a greater prevalence of developing cardiovascular and renal disease (CVRD) than White (W) adults. Elevated sympathetic nervous system activity is associated with increased incidence of CVRD. Physical exertion, such as exercise, acutely increases sympathetic nervous system activity directed towards the kidneys, resulting in renal vasoconstriction and reduced renal blood flow (RBF). Limited research shows that healthy young AA adults exhibit exaggerated sympathetic responsiveness both at rest and during sympathetic activation, which may be a major contributor to the increased risk of CVRD in this population. However, the acute renal vasoconstrictor response to any sympathetic nervous system activation has not been investigated to date in AA adults. During sympathetic nervous system activation such as exercise, sympathetic outflow to the kidneys in AA adults might be exaggerated, contributing to greater renal vasoconstriction and a larger reduction in RBF. Over time, this exaggerated neurovascular response to sympathetic activation could have a negative cumulative effect on the kidneys, which could be a contributing factor to the greater incidence of CVRD in this population.

Therefore, this study aims to examine the renal vasoconstrictor response to sympathetic stressors in healthy AA adults prior to development of CVRD, which will be achieved via two Specific Aims. In Specific Aim 1, the investigators will test the hypothesis that the renal vasoconstrictor response to acute dynamic exercise is exaggerated in healthy young AA compared to W adults. Specifically, the investigators will measure RBF and blood pressure at rest and during cycling exercise to calculate renal vascular resistance responses to exercise, enabling us to test the hypothesis that healthy young AA adults exhibit an exaggerated renal vasoconstrictor response to acute cycling exercise compared to healthy young W adults. In Specific Aim 2, the investigators will test the hypothesis that the renal vasoconstrictor response to non-exercise sympathetic stressors is exaggerated in healthy young AA compared to W adults. Specifically, the investigators will measure RBF and blood pressure at rest and during a cold pressor and mental stress tests to calculate renal vascular resistance responses to these non-exercise sympathetic stressors, enabling us to test the hypothesis that healthy young AA adults exhibit exaggerated renal vasoconstrictor responses to non-exercise sympathetic stressors compared to healthy young W adults.

Using the highly innovative approach of Doppler ultrasound to measure RBF during exercise and non-exercise sympathetic stressors non-invasively and with high temporal resolution will enable us to assess the renal vasoconstrictor response to sympathetic stressors in healthy AA adults prior to development of CVRD, so the underlying integrative physiological responses to sympathetic activation in AA adults can be understood. Findings from this study in this understudied yet clinically significant area will contribute to the ultimate goal of creating and implementing treatment strategies to reduce the risk of developing CVRD in AA adults.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
32
Inclusion Criteria
  • Self-report as either African American or White racial identity
  • Born in United States
  • Both biological parents identify as same racial identity as participant
  • Recreationally active (participating in physical activity for at least 20 minutes per day, at least three times per week, but not training for competitive events)
  • Fluent in English
Exclusion Criteria
  • Hispanic or Latino
  • Females who are pregnant or lactating
  • Cardiovascular or renal disease
  • Hypertension (blood pressure of more than or equal to 130/80 mmHg)
  • Diabetes
  • Obesity (body mass index of more than or equal to 30 kg/m2)
  • Smoker/Tobacco user
  • Acute medical conditions
  • Taking prescribed cardiovascular, antihypertensive, or renal medications

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
Change in renal vascular resistance during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the percent change from pre-acute exercise to during steady-state exercise will be assessed.

Change in renal vascular resistance during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the percent change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in renal vascular resistance during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the percent change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Secondary Outcome Measures
NameTimeMethod
Change in diastolic blood pressure during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in stroke volume during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in renal blood flow velocity during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in heart rate during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in renal blood flow velocity during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Change in mean arterial blood pressure during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Change in renal blood flow velocity during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in mean arterial blood pressure during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in systolic blood pressure during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in heart rate during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in cardiac output during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in total peripheral resistance during acute exercisePre-acute exercise and during steady-state exercise

For the acute exercise intervention, the absolute change from pre-acute exercise to during steady-state exercise will be assessed.

Change in mean arterial blood pressure during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in systolic blood pressure during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in diastolic blood pressure during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in cardiac output during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in total peripheral resistance during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Change in stroke volume during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in total peripheral resistance during cold pressor testPre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test

For the cold pressor test intervention, the absolute change from pre-cold pressor test to 30-second intervals during the cold pressor test will be assessed.

Change in diastolic blood pressure during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Change in systolic blood pressure during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Change in heart rate during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Change in cardiac output during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Change in stroke volume during mental stress testPre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test

For the mental stress test intervention, the absolute change from pre-mental stress test to 1-minute intervals during the mental stress test will be assessed.

Trial Locations

Locations (1)

University of Massachusetts Boston

🇺🇸

Boston, Massachusetts, United States

University of Massachusetts Boston
🇺🇸Boston, Massachusetts, United States
Rachel C Drew, PhD
Principal Investigator

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