In the new study, REGARDS researchers reviewed data on more than 26,500 participants with no history of stroke. They kept in periodic telephone contact with the participants for nearly five years and documented 299 strokes to which they applied a rate formula. In the 45-54 age group, the stroke rate is 192 percent for African-Americans compared with 74 percent for whites.

"That disparity in the incidence rate evens out and changes as you monitor stroke in older Americans. In fact the racial differences reverse, so by the time they reach about age 80 and older, whites have a higher stroke rate compared with blacks," Howard said. It is not clear why the differences change with age, but it may have to do with different types of strokes occurring in different age groups.

The bottom line is that certain subgroups are at greater risk and need to pay closer attention to their stroke-risk factors, said George Howard, Dr.PH., a UAB professor of biostatistics and a REGARDS co-principal investigator. Stroke-risk factors include family history, high blood pressure and high cholesterol, diabetes, obesity, tobacco use and other variables.

Source: University of Alabama at Birmingham