Public Health: Elevated Blood Pressure in Black Patients

Photo: Measuring blood pressure

African-Americans have higher blood pressure; ©
Lorenz Timm

Black patients preoccupied with racial concerns have higher blood pressure than those who are not, according to results of new Johns Hopkins-led research.

The findings suggest that heightened race consciousness could at least in part account for the disproportionately high rate of hypertension in black Americans — the highest prevalence of any group in the United States and one of the highest rates in the world.

"A preoccupation with race among blacks leads to hyper-vigilance, a heightened awareness of their stigmatized status in society and a feeling that they need to watch their backs constantly," says Dr. Lisa A. Cooper. "African-Americans have higher blood pressure, and it has been difficult to explain why this is true. It does not appear to be genetic, and while things like diet, exercise and reduced access to health care may contribute, we think that a tense social environment, the sense of being treated differently because of your race, could also possibly explain some of what's behind the higher rates."

As part of ongoing research into doctor-patient relationships and racial disparities, Cooper and her colleagues surveyed 266 patients in urban health clinics in Baltimore between September 2003 and August 2005. Sixty-two percent of the patients were black. To test for race consciousness, they used the 2002 Behavioral Risk Factor Surveillance System "Reactions to Race" module developed by the U.S. Centers for Disease Control and Prevention. Patients — both black and white — were asked how often they thought about their race.

Two categories were created: Those who said they ever think about their race and those who said they never do. Half of the black patients responded that they "ever" think about it, and one in five white patients said they did.

When blood pressures were measured, being a race-conscious black patient was associated with significantly higher diastolic blood pressure (roughly five millimeters of mercury) and somewhat higher systolic blood pressure (some four millimeters of mercury) than black patients who were not preoccupied with race. There was no effect on blood pressure in race conscious white patients. Systolic blood pressure, the top number in a blood pressure reading, measures the force that pressure from the beating heart places on the arteries moving blood to the rest of the body, while diastolic blood pressure, the bottom number, indicates the pressure in the arteries when the heart rests between beats.

Cooper says it is well known that chronic stress can increase blood pressure. Similarly, she says tasks that require active coping efforts may increase heart rate and systolic blood pressure, while tasks that require quiet attentiveness and vigilance may lead to decreased cardiac output as well as increased diastolic blood pressure.

In addition to the link between race consciousness and blood pressure, Cooper's team found that whites who were race conscious were more likely to feel respected in the doctor-patient relationship than whites who were not concerned with race, though they were less likely to take their blood pressure medication as prescribed.; Source: Johns Hopkins Medicine