Racial Segregation May Impact Blood Pressure

Living in a segregated neighborhood was linked to an increase in blood pressure among black adults, according to a new study published by JAMA Internal Medicine. However, when this population moved away from the segregated areas, a decrease in blood pressure was observed.

These findings provide further evidence that racial segregation may have harmful effects on the health of individuals, especially African Americans who have high rates of hypertension.

Residential segregation has been thought to be a cause of health disparities among races. This is the first study to assess whether it may affect hypertension.

“Our study suggests that the stress and the inadequate access to health-promoting resources associated with segregation may play a role in these increases in blood pressure,” said David Goff, MD, director of the Division of Cardiovascular Diseases of the National Heart, Lung, and Blood Institute (NHLBI). “While stress raises blood pressure, access to health-promoting resources, such as full service grocery stores, recreation centers, and health care clinics, is critical to keeping blood pressure at healthier levels.”

Included in the study were blood pressure readings for 2280 patients who participated in the CARDIA study. These patients were black and aged 18 to 30. Patients were initially screened in 1985 and 1986 and then multiple times over the next 25 years.

The authors categorized neighborhood segregation as high, medium, or low, based on the percentage of black residents in a neighborhood compared with surrounding areas, according to the study.

The investigators discovered that when neighborhoods were more segregated, patients experienced an increase in systolic blood pressure. They also found that that a reduction in segregation was linked to a decrease in blood pressure.

Patients who initially lived in segregated neighborhoods who then moved to a less segregated area saw an average drop in systolic blood pressure of 3 to 5-mm Hg, according to the study.

“This is a powerful effect,” said lead author Kiarri Kershaw, PhD, MPH. “In terms of impact, just 1-mm Hg of reduction of the systolic blood pressure at the population level could result in meaningful reductions in heart attacks, strokes and heart failure.”

The results remained accurate even after accounting for martial status, body mass index, smoking history, physical activity, and socio-economic status of the community, according to the study.

“Longitudinal, long-term studies like CARDIA make this research possible and are critical to our ability to shine a light on the root causes of chronic diseases, such as heart disease,” Dr Goff said. “Only by understanding these root causes can we effectively promote health and health equity at the societal level.”

The authors speculated that improving access to resources for those in segregated neighborhoods and providing opportunities for individuals to move to areas with optimal resources could play a role in reducing racial health disparities, the study concluded.