Study author Dr. Brett Kissela of the University of Cincinnati College of Medicine and colleagues looked at occurrences of strokes in people ages 20-54 in the Greater Cincinnati/Northern Kentucky area during three separate, yearlong periods -- July 1993 to June 1994, and the calendar years of 1999 and 2005.
Only first-ever strokes were included in the analysis.
The study, published in the online issue of Neurology, found the average age of people who experienced stroke fell from age 71 in 1993/1994 to age 69 in 2005. However, strokes among people age 55 and younger made up a greater percentage of all strokes over time, growing from about 13 percent in 1993/1994 to 19 percent in 2005, the study found.
The stroke rate among young African-Americans increased, from 83 strokes per 100,000 people in 1993/1994 to 128 per 100,000 in 2005. It increased among young Caucasians, from 26 strokes per 100,000 people in 1993/1994 to 48 per 100,000 in 2005.
"The reasons for this trend could be a rise in risk factors such as diabetes, obesity and high cholesterol," Kissela said in a statement. "The trend found in our study is of great concern for public health because strokes in younger people translate to greater lifetime disability."