"Neighborhood Disadvantage, Sleep and Vascular Health"

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.

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.

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).

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.

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).

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.

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.

The investigators will use electron paramagnetic resonance to measure reactive oxygen species (spectra units) in whole blood samples treated with a spin probe.

The investigators will measure nitric oxide metabolites (nitrate and nitrite nanomolar concentration) using chemiluminescence

Participants will wear an ActiGraph GT3X accelerometer for seven days to objectively quantify steps per day and metabolic equivalents per day.

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.

The investigators will administer the Beck's Depression Inventory. The scale starts at 0 and ends at 3 for 21 questions related to depression.

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.

The investigators will instruct participants to complete a diet log for 5 days which will be operationalized with Nutrition Data System for Research (NDSR).

The investigators will use an electrolyte analyzer to assess sodium, potassium, and chloride concentration. The investigators will use urine volume and electrolyte concentration to determine 24-hour electrolyte excretion