Lifetime discrimination may increase risk of hypertension among African Americans

"Previous studies have shown that discrimination affects African Americans' health; however, this research is one of the first large, community-based studies to suggest an association between discrimination over a lifetime and the development of hypertension among a large sample of African American men and women," said Allana T. Forde, Ph.D., M.P.H., the study's first author and a postdoctoral research fellow at the Urban Health Collaborative at Drexel University in Philadelphia, Pennsylvania.

"African Americans continue to be disproportionately affected by hypertension, making it imperative to identify the drivers of hypertension in this population," Forde said. "Greater lifetime discrimination was associated with an increased risk for hypertension among African Americans in this study, which reflects the impact of cumulative exposure to stressors over one's lifetime and the physiological reactions to stress that contribute to deleterious health outcomes."

Researchers reviewed data on 1,845 African Americans, ages 21 to 85, enrolled in The Jackson Heart Study, which focused on cardiovascular disease among African Americans in the tri-county areas of Jackson, Mississippi. The study participants did not have hypertension during the first visit in 2000 through 2004. Patients completed two follow-up study visits: one in 2005 through 2008, and the second between 2009 through 2013. Participants self-reported their discrimination experiences through in-home interviews, questionnaires and in-clinic examinations.

Participants were defined as having hypertension if they said they were taking blood pressure-lowering medication, or had a systolic blood pressure of 140 mm Hg or above or diastolic blood pressure higher than 90 mm Hg at follow-up visits.

During the follow-up period, more than half of the participants (954 or 52%) developed hypertension. Participants who reported medium levels compared to low levels of lifetime discrimination had a 49% increased risk for hypertension after accounting for other risk factors.

"The study has important implications for patient care and population health," Forde said. "Traditional risk factors, such as diet and physical activity, have been strongly correlated with hypertension, yet important psychosocial factors like discrimination, which also have the potential to negatively impact health, are rarely considered when evaluating the risk for hypertension among African Americans in health care settings."

"Our findings highlight the need for health care professionals to recognize discrimination as a social determinant of health. Health care professionals who understand the importance of unique stressors like discrimination that impact the health of African Americans will be better equipped to provide optimal patient care to this population."

"However, medical care is not enough. More broadly, our results suggest how social determinants such as racism and discrimination affect health in measurable ways. Addressing these factors is critical to reducing rates of chronic diseases."

The researchers note that although the study included experiences of discrimination among a large sample of African Americans, discrimination was measured at a single point in time, which limited the researchers' ability to capture changes in discrimination experiences over the entire follow-up period.

Researchers said additional studies with African Americans in other regions of the U.S. are warranted to confirm the findings of this study. However, these results add to a large body of work documenting the impact of discrimination on the health of African Americans. Strategies to reduce health inequities and improve health are needed to address these broader social determinants.

Co-authors are Mario Sims, Ph.D., M.S.; Paul Muntner, Ph.D., M.H.S.; Tené Lewis, Ph.D.; Amanda Onwuka, Ph.D., M.P.H.; Kari Moore, M.S.; and Ana V. Diez Roux, M.D., Ph.D., M.P.H.

The Jackson Heart Study was supported by Jackson State University; Tougaloo College; the Mississippi State Department of Health; the University of Mississippi Medical Center; the National Heart, Lung, and Blood Institute and the National Institute for Minority Health and Health Disparities of the National Institutes of Health; and the American Heart Association.