Exercise-Induced Kidney Blood Flow Response in African American Adults

Overseen By Rachel C Drew, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Massachusetts, Boston

Must not be taking: Cardiovascular, Antihypertensive, Renal

Disqualifiers: Hypertension, Diabetes, Obesity, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

32 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand how exercise and stress affect kidney blood flow in healthy young African American adults compared to White adults. Participants will engage in activities such as cycling (acute exercise), a cold hand test (cold pressor test), and solving math problems (mental stress test) to measure changes in kidney and heart functions. The goal is to learn why African American adults often face more kidney and heart issues, with hopes of finding ways to reduce these health problems. The trial seeks individuals who self-identify as African American or White, were born in the United States, are physically active but not competitive athletes, and have no major health conditions like high blood pressure or diabetes.

As an unphased study, this trial offers a unique opportunity to contribute to understanding health disparities and improving future treatments.

Do I need to stop my current medications for the trial?

Yes, you will need to stop taking any prescribed cardiovascular, antihypertensive, or renal medications to participate in this trial.

What prior data suggests that these tests are safe for participants?

Previous studies have shown that a single session of moderate exercise keeps kidney blood flow steady without harming the kidneys, suggesting that this exercise is generally safe for the kidneys.

Research on the cold pressor test, which involves exposure to cold, shows that it can raise blood pressure but is usually well-tolerated and safe for most people.

Studies indicate that the mental stress test can increase heart rate and blood pressure, but it is also considered safe for participants.

Overall, these activities—exercise, cold exposure, and mental stress—are generally safe and well-tolerated in healthy individuals, typically not causing harm to the kidneys or other organs. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it examines how different stressors like exercise, cold exposure, and mental stress affect kidney blood flow in African American and White adults. Unlike traditional treatments that focus on medication, this study uses physiological tests to understand the body's natural responses. By observing beat-to-beat renal blood flow and other vital signs, researchers hope to uncover insights into how stress impacts kidney function across different racial groups. This could lead to more personalized approaches in managing kidney health.

What evidence suggests that this trial's treatments could be effective for understanding kidney blood flow response in African American adults?

This trial will compare the effects of acute exercise, a cold pressor test, and a mental stress test on kidney blood flow in African American adults. Research has shown that aerobic exercise can significantly lower blood pressure in African American women, with a 6.3% drop in systolic pressure during stress. Exercise also correlates with improved kidney function, suggesting potential benefits for kidney health.

In the cold pressor test, Black individuals often exhibit stronger blood pressure responses, which may relate to a higher risk of hypertension. This test helps clarify how stress affects blood pressure differently among races.

For the mental stress test, stress has been linked to a faster decline in kidney function among African Americans, indicating that managing stress could be crucial for protecting kidney health. These studies aim to clarify how stress and exercise affect kidney blood flow, particularly in African Americans. ^{6 7 8 9 10}

Who Is on the Research Team?

Rachel C Drew, PhD

Principal Investigator

University of Massachusetts, Boston

Are You a Good Fit for This Trial?

This trial is for African American and White adults born in the U.S., fluent in English, who are active but not training competitively. Participants must have parents of the same racial identity. It excludes pregnant or lactating women, those with hypertension, diabetes, obesity, smokers, or anyone with cardiovascular/renal disease.

Inclusion Criteria

You exercise regularly for at least 20 minutes per day, three times per week, but you are not a competitive athlete.

Born in United States

Fluent in English

Exclusion Criteria

I have heart or kidney disease.

You use tobacco or smoke cigarettes.

I am not pregnant or breastfeeding.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Exercise Intervention

Participants undergo acute dynamic exercise to measure renal blood flow and blood pressure responses

1 session

1 visit (in-person)

Cold Pressor and Mental Stress Tests

Participants undergo cold pressor and mental stress tests to measure renal vascular resistance and other cardiovascular responses

1 session

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after interventions

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Acute exercise
• Cold pressor test
• Mental stress test

Trial Overview The study investigates how acute exercise and stress tests (cold pressor test and mental stress test) affect kidney blood flow in healthy African American adults compared to Whites. The goal is to understand if there's an exaggerated response that could contribute to higher rates of cardiovascular and renal diseases.

How Is the Trial Designed?

Group I: White Adults Experimental Treatment 3 Interventions

White adults will undergo the interventions of acute exercise, a cold pressor test, and a mental stress test while beat-to-beat renal blood flow velocity, mean arterial blood pressure, and heart rate are recorded.

Group II: African American Adults Experimental Treatment 3 Interventions

African American adults will undergo the interventions of acute exercise, a cold pressor test, and a mental stress test while beat-to-beat renal blood flow velocity, mean arterial blood pressure, and heart rate are recorded.

Who Is Running the Clinical Trial?

University of Massachusetts, Boston

Lead Sponsor

Trials

42

Recruited

17,800+

National Heart, Lung, and Blood Institute (NHLBI)

Collaborator

Trials

3,987

Recruited

47,860,000+

Published Research Related to This Trial

In a study of 119 normotensive and mildly to moderately hypertensive individuals, baseline blood pressure at rest was found to be a strong predictor of ambulatory blood pressure at work, indicating its importance in monitoring blood pressure levels.

Among various stress-inducing tasks, psychological challenges like structured interviews and video games were the most significant predictors of ambulatory blood pressure, with the cold pressor test showing a notably stronger correlation for diastolic blood pressure in black participants compared to white participants.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Predicting home and work blood pressure measurements from resting baselines and laboratory reactivity in black and white Americans. Ironson, GH., Gellman, MD., Spitzer, SB., et al.[2022]

In a study examining cardiovascular responses to stress in women, Black participants showed a slower recovery of diastolic blood pressure after mental arithmetic tasks, indicating potential differences in cardiovascular reactivity compared to White participants.

During the cold face stimulus, Black women exhibited significantly greater increases in systolic blood pressure than White women, suggesting that race may influence vascular responses to stress, although parental history of hypertension did not significantly affect these responses.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Race, parental history of hypertension, and patterns of cardiovascular reactivity in women. Anderson, NB., Lane, JD., Taguchi, F., et al.[2022]

In healthy humans, static handgrip exercise leads to a significant decrease in renal cortical blood flow and an increase in renal vascular resistance, indicating that exercise affects kidney blood supply.

The study identified that both central command and mechanoreflex mechanisms contribute to the early decrease in renal blood flow during exercise, while the muscle metaboreflex further decreases blood flow after exercise, suggesting complex regulatory mechanisms at play.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Modulation of renal cortical blood flow during static exercise in humans. Middlekauff, HR., Nitzsche, EU., Nguyen, AH., et al.[2019]

In two studies involving 10 healthy young adults, neither 30 minutes of moderate intensity aerobic exercise nor 30 seconds of maximal effort anaerobic exercise changed the increase in renal vascular resistance (RVR) during sympathetic stimulation, indicating that prior exercise does not affect kidney response to stress.

Both types of exercise did not alter the renal blood velocity response to sympathetic stimulation, suggesting that the body's ability to regulate kidney blood flow remains consistent regardless of prior aerobic or anaerobic activity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Renal Hemodynamics During Sympathetic Activation Following Aerobic and Anaerobic Exercise. Schlader, ZJ., Chapman, CL., Benati, JM., et al.[2020]

In a study involving 20 young women (12 White and 8 Black), it was found that Black women had significantly higher brachial mean arterial and diastolic blood pressure compared to White women after acute supramaximal exercise, indicating potential differences in cardiovascular responses.

Additionally, Black women exhibited lower heart rate variability, suggesting a different autonomic modulation compared to White women, which may influence how exercise prescriptions should be tailored for different racial groups.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Racial Differences in Blood Pressure and Autonomic Recovery Following Acute Supramaximal Exercise in Women. Bajdek, N., Merchant, N., Camhi, SM., et al.[2023]

In a study of 83 normotensive Black and White men and women aged 25 to 44, Black participants exhibited significantly higher diastolic blood pressure responses during a cold pressor test compared to White participants, indicating potential racial differences in cardiovascular reactivity.

The study also found that exercise led to greater systolic blood pressure increases in Black women compared to Black men and White women, suggesting that both race and sex influence physiological responses to stressors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cardiovascular and neurohumoral responses to behavioral challenge as a function of race and sex. Tischenkel, NJ., Saab, PG., Schneiderman, N., et al.[2022]

Aerobic exercise significantly reduces blood pressure reactivity to stress in healthy African-American females, as shown by a 6.3% decrease in systolic pressure during a cold pressor test after a 6-week training program.

The study involved 13 participants (8 trained and 5 sedentary), and the trained group also showed a notable 24.1% increase in their peak oxygen uptake (VO2peak), indicating improved cardiovascular fitness, which may help lower hypertension risk.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Aerobic exercise attenuates blood pressure reactivity to cold pressor test in normotensive, young adult African-American women. Bond, V., Mills, RM., Caprarola, M., et al.[2022]

In a study involving 12 baboons, renal blood flow decreased by about 19% during dynamic leg exercise, indicating that exercise can significantly affect kidney blood supply.

The decrease in renal blood flow occurred quickly within 1.5 minutes of exercise onset and was primarily controlled by neural mechanisms, similar to responses observed in humans.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Decreased renal blood flow in the baboon during mild dynamic leg exercise. Hohimer, AR., Smith, OA.[2017]

In a study of 30 young adult African-American males, those who were physically active had significantly higher peak oxygen consumption compared to their inactive counterparts, indicating better cardiovascular fitness.

Despite the differences in fitness levels, both physically active and inactive groups showed similar blood pressure responses during a cold pressor test, suggesting that regular physical activity does not necessarily lead to a reduced blood pressure reaction to acute stress in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Physical activity and blood pressure responsiveness to the cold pressor test in normotensive young adult African-American males. Bond, V., Adams, RG., Vaccaro, P., et al.[2022]

In a study involving 13 non-hypertensive volunteers, cardiovascular responses to the cold pressor test (CPT) were found to be reproducible, indicating reliable measurements of heart rate, blood pressure, blood flow, and skin temperature.

Exercise significantly reduced the cardiovascular responses to cold stress, suggesting that regular physical activity may help mitigate the body's reaction to cold, which could be beneficial in identifying individuals at risk for hypertension and promoting preventative exercise programs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Reproducibility of exercise-induced modulation of cardiovascular responses to cold stress. Rashed, HM., Leventhal, G., Madu, EC., et al.[2019]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT03981640

Neural Control of Kidney Blood Flow During Exercise in ... 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 ...

2. withpower.com withpower.com/trial/phase-2022-822ea

Exercise-Induced Kidney Blood Flow Response in African ... Aerobic exercise significantly reduces blood pressure reactivity to stress in healthy African-American females, as shown by a 6.3% decrease in systolic pressure ...

3. centerwatch.com centerwatch.com/clinical-trials/listings/NCT03981640/neural-control-of-kidney-blood-flow-during-exercise-in-african-american-adults?state=MA&city=Dorchester

Neural Control of Kidney Blood Flow During Exercise in ... 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 ...

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11471621/

The association of physical activity with kidney function risk ... Long working hours are likely associated with the decreased of kidney function, while physical activity (PA) was linked to improvements in kidney function.

5. clinicontact.com clinicontact.com/umass-boston/exercise-kidney-blood-flow-aa

Exercise & Kidney Blood Flow AA This study is focused on understanding how the cardiovascular system works during exercise and how blood flow to the kidneys is affected in individuals from ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9081410/

Potential implications of blood flow restriction exercise on ... Current literature suggests that BFR training displays similar positive health benefits to exercise training alone for CKD patients.

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6530612/

Blood Flow Restriction Exercise: Considerations of ... This covers the use of blood flow restriction to enhance muscular strength and hypertrophy via training with resistance and aerobic exercise.

8. sciencedirect.com sciencedirect.com/science/article/pii/S2095254624000231

Concerns about the application of resistance exercise with ... The application of blood-flow restriction to maximize the effects of physical exercise may not be a safe alternative for most hemodialysis patients with ...

9. physoc.onlinelibrary.wiley.com physoc.onlinelibrary.wiley.com/doi/10.14814/phy2.15420

The moderate‐intensity continuous exercise maintains renal ... These findings indicate that a single bout of moderate-intensity continuous exercise maintains RBF and does not induce renal injury.

10. bmcnephrol.biomedcentral.com bmcnephrol.biomedcentral.com/articles/10.1186/s12882-021-02618-1

Clinical practice guideline exercise and lifestyle in chronic ... We recommend that haemodialysis patients should aim for 150 min of moderate intensity activity a week (or 75 min of vigorous activity) or a ...