Sleep and Circadian Study: Disparity in Prevalence of Hypertension Between Black and White Americans

Alarm clock on table

Blog submitted by: Shelby Watkins, M.P.H, Research Associate and Latroy Robinson, B.S., Research Assistant

The U.S. Department of Health and Human Services reports that African Americans are 40% more likely to have high blood pressure and are less likely than non-Hispanic whites to have their blood pressure under control. Hypertension is common in African Americans, particularly hazardous non-dipping hypertension where blood pressure does not reduce healthily across the night, which is associated with increased morbidity and mortality from cardiovascular disease. Non-dipping is a term that describes the change in blood pressure during the daytime compared with the nighttime.

Institute scientist, Dr. Nicole Bowles, Ph.D. is leading a study to determine underlying mechanisms that can help determine non-dipping nocturnal blood pressure patterns. The research team will study non-dipping blood pressure from stress accumulated over a person’s life and how that can impact their internal body clock and sleep. This research will lay the groundwork for better treatment of hypertension especially in cases where hypertension is difficult to treat among African Americans.

If you or someone you know is interested in learning more about the study and are between the ages of 30-60 years old, self-identify as black or white and are currently not taking any medications, contact or visit the following link: to fill out a short survey. Those who qualify to participate in the 7 day/6-night study, will stay in our OHSU hospital facility and can earn up $2,400 in compensation, plus access to many of your health results from the study.

As our research team begins our return to clinical research at OHSU during COVID-19, we are taking numerous precautions to ensure the safety of the volunteer research participants as well as staff members throughout the initial screening visits to longer visits where participants remain in an on-site OHSU laboratory suite for a whole week. First, all staff and research participants must pass a health screening for any symptoms of COVID-19 each time they come to OHSU for the study. Second, all research participants who are scheduled for the week-long study will be tested for COVID-19 in the days before entering the laboratory. And while in the laboratory, some of the more noticeable precautions include having the volunteer participant and all staff wear fluid-grade face masks whenever they are in the same room together. Additionally, we are reducing the number of research staff who will enter the participant’s research suite, and we will maintain 6-feet of physical distancing whenever possible. Some testing cannot be done without the researchers getting close to a participant, for instance to take biological samples or blood pressure measurements, and when this occurs, staff members will use face shields and gloves to minimize any risk of viral transmissions.

To ensure a comfortable environment during the in-lab stay, participants will not need to wear their mask when they are alone in their suite or during downtime between study measures. Participants have access to a wide array of movies/TV shows and music to keep themselves entertained during the time between measures, as well as the option to bring books, journals, coloring books and puzzles from home. So that the volunteers can remain in contact with their social network during the in-lab stay, participants can receive occasional emails from designated loved ones and friends, which will need to be relayed via the research staff. The research team is committed to continuing their work and protecting the safety and health of study participants and staff during these unprecedented times.

OccHealthSci sleep resources: