Evaluating the Relationship Between Stress, Ethnicity, and Blood Pressure

High blood pressure affects nearly one third of all people in the United States. It can be
caused by many factors, including obesity, sodium intake, genetics, and stress. Ethnicity
appears to also play a role, because African Americans are more susceptible to developing
high blood pressure than other ethnic groups, with more than 40% of African Americans
diagnosed with this condition. This study will examine the underlying reasons of why stress
and African-American ethnicity contribute to high blood pressure risk and how ethnicity and
stress interact with each other to increase this risk. Specifically, study researchers will
examine how stress increases blood pressure, how people from different ethnic groups respond
to stress differently, and how sleep plays a role in regulating blood pressure levels.

This study will enroll African Americans and Caucasians who have high blood pressure, as
well as African Americans and Caucasians who have normal blood pressure. Potential
participants will go through a screening process that involves a medical history review,
questionnaires, and blood pressure monitoring. Eligible participants will then be admitted
to the research clinic for a 2-night stay. Participants' nutrition history and body
measurements will be obtained, and a catheter will be inserted into the arm so that blood
can be easily collected during the clinic stay. During the night, participants' breathing
habits and movements will be monitored while they sleep. During the day, blood pressure and
heart activity will be monitored frequently, including when participants are asked to
perform mildly stressful tasks, such as giving a short speech. Various medications that
affect heart rate and blood pressure will be given at different times during the study, and
researchers will monitor participants' reactions to each medication. Lastly, participants
will also complete psychological questionnaires.

Inclusion Criteria:

- Self-identifies as African American or Caucasian

- Weighs 85% to 150% of ideal weight (approximate BMI of 17.5 to 30)

- In good physical health

Exclusion Criteria:

- Blood pressure greater than 180/110 mm Hg at any point in the past

- Currently works less than half-time

- Currently is employed doing shift work

- Currently takes prescription medication, other than anti-hypertensive medication

- Currently smokes