Black women in the United States are much more likely to have high blood pressure than black men or white women and white men, according to a new study

The researchers also found that blacks are twice as likely as whites to have undiagnosed and untreated high blood pressure. "For many years, the focus for high blood pressure was on middle-aged men who smoked. Now we know better," said study author Dr. Uchechukwu Sampson, an assistant professor of medicine at Vanderbilt University Medical Center in Nashville, Tennessee. For the study, researchers examined data from 70,000 people in 12 southeastern states known as the "stroke belt." This region has higher rates of stroke than anywhere else in the United States. High blood pressure is a risk factor for stroke, the researchers said. The overall rate of high blood pressure among the people in the study was 57%, but was higher in blacks (59%) than whites (52%). The rate among black women was 64%, compared with 52% in white women and 51% in both black and white men. Among the study participants with high blood pressure, 31% of black men were undiagnosed, along with 28% of black women, 27% of white men and 17% of white women. Blacks were twice as likely as whites to have uncontrolled high blood pressure, and men were more likely than women to have uncontrolled high blood pressure.