Neighborhood Disadvantage, Sleep and Vascular Health

Study Overview
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Brief Summary
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The purpose of the study is to find out the effects of neighborhood disadvantage and sleep disparities contribute to racial disparities in cardiometabolic health and blood pressure in young adults.

Detailed Description
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There are well-documented disparities between Black and white Americans in the incidence of cardiovascular disease, the leading cause of death in America. There are also disparities between Black and White Americans in the incidence of hypertension (high blood pressure; BP), which is the leading risk factor for cardiovascular disease. Our long-term goal is to determine effective strategies to prevent racial disparities in cardiovascular health. In this proposal, the investigators will focus on determining societal and biological mediators of racial disparities in young adults that can be targeted in future interventions. Poor sleep is associated with adverse cardiovascular events and hypertension. Moreover, recent meta-analyses demonstrate that Black adults have consistently poorer sleep health than White adults, including receiving fewer total sleep minutes and having worse overall sleep quality. Neighborhood socioeconomic environments influence health behaviors through both material resources (e.g., access to healthful foods and safe public space) and social norms (e.g. exercise, diet, smoking). A well-documented history of discriminatory policies and practices has resulted in black individuals living in more disadvantaged physical and social environments than whites. As such, they experience greater adverse exposures (e.g., racism, violence and stress), which negatively impact sleep, resulting in dysregulation of cardiometabolic health. Therefore, the investigators seek to determine the role of neighborhood disadvantage and sleep in contributing to racial disparities in cardiovascular health.

Official Title
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Neighborhood Disadvantage, Sleep, and Vascular Health: Racial Disparities in Cardiometabolic Health and Blood Pressure

Conditions
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Blood Pressure, Sleep, Racism, Stiffness, Arterial, Endothelial Dysfunction

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Exclusion Criteria: Systolic blood pressure greater than 150 mmHg Diastolic blood pressure greater than 90 mmHg Body mass index above 35 kg/m^2 History of cardiovascular disease Recent (one year) history of cancer History of metabolic disease (e.g. type 2 diabetes)

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| College Students<br>The cohort consists of Black and White college students at a university in a southeastern state in America. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flow-mediated dilation (FMD) | Flow-mediated vasodilation will be assessed using continuous measures of brachial artery diameter and velocity via duplex Doppler ultrasound (Hitachi Arietta 70). The brachial artery will be imaged in the longitudinal plane proximal to the medial epicondyle using a high-frequency (6-12 MHz) linear-array probe. The ultrasound probe will be stabilized using a custom-built clamp. Shear rate (sec-1) will be calculated as [(blood flow velocity (cm*s-1) *4)/blood vessel diameter (mm)] The image will be recorded throughout a 60-s baseline, a 300-s ischemic stimulus (250 mmHg), and 180 seconds post deflation. FMD will be expressed as % dilation (final diameter-baseline diameter/baseline diameter x 100) and also normalized to the shear stimulus. Allometric scaling will be used if appropriate, including if there are baseline differences in artery diameter by race or condition. | Baseline racial comparison | 
| Pulse wave velocity (arterial stiffness) | The investigators will use the SphygmoCor XCEL system to assess pulse wave velocity (PWV). A high-fidelity strain-gauge transducer is used to obtain the pressure waveform at the carotid pulse. Distances from the carotid artery sampling site to the femoral artery (upper leg instrumented with a thigh cuff for oscillometric sphygmomanometry), and from the carotid artery to the suprasternal notch will be recorded.PWV will be expressed as cm/s. | Baseline racial comparison | 
| Pulse wave analysis (arterial stiffness) | The investigators will use the SphygmoCor XCEL system to assess pulse wave analysis (PWA) using an upper arm blood pressure cuff. PWA will be expressed as % (calculated as augmentation pressure divided by the pulse pressure). | Baseline racial comparison | 
| 24-hour ambulatory blood pressure | Participants will wear an Oscar2 (with SphygmoCor) ambulatory blood pressure monitor on their upper arm for up to 24-hours preceding their study visit to measure systolic and diastolic blood pressure. The purpose of the ambulatory blood pressure monitoring is to determine blood pressure regulation over an entire day. This blood pressure monitor will be set to automatically take blood pressure every 20 minutes. The monitor records and saves each blood pressure measurement automatically. | Baseline racial comparison | 
| Blood pressure reactivity | The investigators will measure systolic and diastolic pressure using photoplethysmography at the finger. Systolic and diastolic blood pressure will be assessed at rest and during handgrip exercise. Blood pressure reactivity will be expressed as a change in pressure (mmHg) from baseline to a predetermined time during the stressor (e.g., minute one average and minute two average). | Baseline racial comparison | 
| Objective sleep duration and quality | Philips actiwatch spectrum will be used to quantify sleep duration. Participants will wear the watch units for 7 days. The investigators will cross-check actigraphy wear times with a sleep diary. | Baseline racial comparison | 
| Subjective sleep quality | The investigators will use the Pittsburgh Sleep Quality Index (PSQI) to asses sleep duration and perceived sleep quality reflective of the one month period leading into the study. The PSQI global score has a possible range of 0-21 points. | Baseline racial comparison | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Circulating reactive oxygen species | The investigators will use electron paramagnetic resonance to measure reactive oxygen species (spectra units) in whole blood samples treated with a spin probe. | Baseline racial comparison | 
| Blood biomarkers of nitric oxide bioavailability | The investigators will measure nitric oxide metabolites (nitrate and nitrite nanomolar concentration) using chemiluminescence | Baseline racial comparison | 
| Physical activity | Participants will wear an ActiGraph GT3X accelerometer for seven days to objectively quantify steps per day and metabolic equivalents per day. | Baseline racial comparison | 
| Mental health - social anxiety | The investigators will administer the Liebowitz Social Anxiety Scale. The scale starts at 0 (none) and ends at 3 (severe) for 24 questions related to anxiety and avoidance, and a cumulative score is calculated. | Baseline racial comparison | 
| Mental health - depression | The investigators will administer the Beck's Depression Inventory. The scale starts at 0 and ends at 3 for 21 questions related to depression. | Baseline racial comparison | 
| Neighborhood disadvantage | The investigators will ask participants to identify their home addresses with investigator assistance and Google maps and potential assistance from their guardians or parents during early- and mid-childhood and adolescence. The investigators will use the participant's address and census tract information to determine measures of neighborhood quality such as median income, crime rates, and median education level. | Baseline racial comparison | 
| Habitual dietary intake | The investigators will instruct participants to complete a diet log for 5 days which will be operationalized with Nutrition Data System for Research (NDSR). | Baseline racial comparison | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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blood pressure, sleep, endothelial dysfunction, social determinants of health, arterial stiffness