More young people are having strokes while older people are having fewer, according to data from Ohio and Kentucky presented at the American Stroke Association's International Stroke Conference 2010.
The average age of stroke patients in 2005 was nearly three years younger than the average age of stroke patients in 1993 — a significant decrease, researchers said. Moreover, the percentage of people 20 to 45 having a stroke was up to 7.3 percent in 2005 from 4.5 percent in 1993.
"This is scary and very concerning," said Brett M. Kissela, M.D., the study's lead author and Associate Professor, Co-Director of the Neurology Residency Program, and Vice-Chair of Education and Clinical Services at the University of Cincinnati Neuroscience Institute.
"What was shocking was the proportion of patients under age 45. The proportion is up, the incidence rate is up."
Stroke has traditionally been considered a disease of old age, so the findings are of great public health significance because of the potential for greater lifetime burden of disability among younger patients.
Kissela said he became interested in studying the issue after observing an increase in young stroke patients admitted to his hospital.
Researchers examined data from the Greater Cincinnati/Northern Kentucky region, which includes about 1.3 million people. But Kissela said the trend noted is likely occurring throughout the United States because the higher prevalence of risk factors such as obesity and diabetes seen in the young here are also seen throughout the country.
They recorded the age of people hospitalized for their first-ever stroke from the summer of 1993 to the summer of 1994, then compared it to calendar years 1999 and 2005.
In 1993, the average age of first stroke was 71.3 years old. The average age dropped to 70.9 in 1999 and was down to 68.4 by 2005.
Researchers also found racial differences in stroke incidence. For blacks, the incidence of strokes among those over age 85 dropped significantly by 2005. For whites, the incidence decreased significantly starting at age 65 by 2005.
In both races, the incidence rates for strokes in 20 to 45 year olds increased, although the increase was only statistically significant among whites, doubling from 12 per 100,000 people to 25 per 100,000.
Kissela said it's hard to know with certainty what is driving this change, but speculated the increased prevalence of diabetes, hypertension and obesity is a major contributor.
"As physicians, we need to look for these potent risk factors even in young people," he said. "Stroke is a life-changing, devastating disease. It can affect young people, and we hope these data will serve as a wake-up call.
"From a public health standpoint, we need to do our best to prevent stroke at any age and monitor for stroke and stroke risk factors in all patients."
Explore further: Incidence of stroke decreases over last 50 years