The systolic blood pressure readings of African-Americans dropped between one to five points when they moved to less segregated neighborhoods, reports a new Northwestern Medicine study published in JAMA Internal Medicine.
It is the first study to look at the longitudinal effects of living in less segregated areas on blood pressure and to compare the effect within the same individuals. Previous research showed racial residential segregation is related to a prevalence of hypertension at a single point in time.
“This study provides stronger, more direct evidence that segregation impacts blood pressure and harms the health of African-Americans,” said lead author Dr. Kiarri Kershaw, assistant professor of Preventive Medicine in the Division of Epidemiology. “I believe it’s related to the stress of living in these neighborhoods.”
Less stress, achieved by decreasing exposure to violence and improving opportunities for socioeconomic mobility, is likely a key factor in blood pressure reductions, Dr. Kershaw said.
“In a less violent area with better resources, you are more secure about your family’s safety and your children’s future in better schools,” Dr. Kershaw said. “You see opportunities for the economic mobility of your kids. And there is better access to good grocery stores, healthcare and an economically vital business district.”
The change in blood pressure was not related to poverty or household income, but increases in educational attainment were related to reductions in blood pressure.
The study examined longitudinal associations of racial residential segregation with blood pressure in more than 2,000 African-American participants of the Coronary Artery Risk Development in Young Adults (CARDIA) study, a national study of adults who have been followed for approximately 25 years. Investigators looked at the associations of within-person change in exposure to segregation and within-person change in blood pressure. The participants were ages 18 to 30 at baseline and ages 43 to 55 at follow-up.
The four CARDIA sites are in Chicago; Birmingham, Alabama; Minneapolis and Oakland, California.
Dr. Mercedes Carnethon, assistant professor of Preventive Medicine in the Division of Epidemiology, was a co-author on the paper.
The research is supported by grants P60 MD002249 from the National Institute on Minority Health and Health Disparities, HHSN268201300025C, HHSN268201300026C, HHSN268201300027C, HHSN268201300028C, HHSN268201300029C, HHSN268200900041C and AG0005 from the National Heart, Lung and Blood Institute and the Intramural Research Program of the National Institute on Aging, all of the National Institutes of Health.