Clinical trial NCT03981640: Neural Control of Kidney Blood Flow During Exercise in African American Adults
Official title: Neurovascular Control of Renal Blood Flow During Exercise in African American Adults
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Healthy
Keywords: Exercise
Cold stress
Mental stress
Lead sponsor: University of Massachusetts, Boston
Sponsor class: OTHER
Collaborators: name: National Heart, Lung, and Blood Institute (NHLBI)
First posted: 2019-06-11
Enrollment: 32
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.

Eligibility criteria: 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

Primary outcomes:
measure: Change in renal vascular resistance during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in renal vascular resistance during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in renal vascular resistance during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
Secondary outcomes:
measure: Change in renal blood flow velocity during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in mean arterial blood pressure during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in systolic blood pressure during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in diastolic blood pressure during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in heart rate during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in cardiac output during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in stroke volume during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in total peripheral resistance during acute exercise
timeFrame: Pre-acute exercise and during steady-state exercise
measure: Change in renal blood flow velocity during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in mean arterial blood pressure during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in systolic blood pressure during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in diastolic blood pressure during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in heart rate during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in cardiac output during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in stroke volume during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in total peripheral resistance during cold pressor test
timeFrame: Pre-cold pressor test to after 30, 60, 90, and 120 seconds of cold pressor test
measure: Change in renal blood flow velocity during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
measure: Change in mean arterial blood pressure during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
measure: Change in systolic blood pressure during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
measure: Change in diastolic blood pressure during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
measure: Change in heart rate during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
measure: Change in cardiac output during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
measure: Change in stroke volume during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
measure: Change in total peripheral resistance during mental stress test
timeFrame: Pre-mental stress test to after 1, 2, 3, 4, and 5 minutes of mental stress test
Other outcomes:
measure: Rating of perceived exertion during acute exercise
timeFrame: During last 30 seconds of steady-state exercise
measure: Rating of hand pain during cold pressor test
timeFrame: During last 30 seconds of cold pressor test
measure: Rating of cold perception during cold pressor test
timeFrame: During last 30 seconds of cold pressor test
measure: Rating of perceived stress during mental stress test
timeFrame: During last 30 seconds of mental stress test
Locations:
city: Boston
country: United States
facility: University of Massachusetts Boston
state: Massachusetts
Study officials:
affiliation: University of Massachusetts, Boston
name: Rachel C Drew, PhD
role: PRINCIPAL_INVESTIGATOR
References: