Even small rise in blood pressure can harm black patients
A rise of as little as 10 mm Hg in systolic blood pressure in blacks raised the risk of dying during the study by 12 percent.
The risk was even greater for black people under 60 - each additional 10 mm Hg increased the risk of dying early by 26 percent, compared with a 9 percent increase for those over 60, the study showed.
"These findings should urge doctors and patients to consider all the available data and weigh the risks and benefits prior to selecting a blood pressure goal in African-American patients," said lead researcher Dr. Tiffany Randolph.
She's a cardiologist with the Cone Health Medical Group HeartCare in Greensboro, N.C.
Blood pressure is made up of two numbers. The top number is called systolic pressure. This measures the pressure in the arteries when blood is being pumped from the heart.
The bottom number - diastolic pressure - measures the pressure between heartbeats. Blood pressure is expressed in millimeters of mercury (mm Hg).
The 2014 blood pressure guidelines from the U.S. National Institutes of Health Eighth Joint National Committee changed blood pressure goals for patients over 60 without diabetes or kidney disease.
The goal was changed to a target of less than 150/90 mm Hg. Previously the goal had been 140/90 mm Hg, Randolph said.
Although the recommendations were based on clinical trials, the trials didn't include many black people, she said.
"Our data suggest that increases in blood pressure are associated with greater risk of death among all ages of African-Americans, even people over age 60," Randolph said.
Only about 50 percent of all people with high blood pressure reach these goals. And because black people are more likely to have high blood pressure and suffer from its consequences, such as stroke, heart attack and kidney failure, "there is concern that raising the recommended blood pressure goals in this population may have unintended consequences," Randolph said.
Moreover, even though the increased risk of death from high blood pressure was smaller among people 60 or older, they may actually benefit most by having well-controlled blood pressure, as their overall risk of death is higher than those under 60, she said. ■