Stroke Incidence Rising Among Younger Adults

Pauline Anderson

February 25, 2010

February 25, 2010 (San Antonio, Texas) — The good news is that fewer older people are having strokes, a new study finds. The bad news is that the difference is being made up by younger patients, among whom stroke incidence appears to be on the rise.

New data from a study of stroke incidence in Ohio and Kentucky show that the average age of a stroke patient decreased by nearly 3 years between 1993-1994 and 2005. During the same period, the percentage of stroke patients aged 20 to 45 years increased from 4.5% to 7.3%.

The study was presented here at the International Stroke Conference 2010.

Link to Increasing Obesity and Diabetes?

Although the study could not determine the cause for the increase in strokes in younger people, poor diet and inactive lifestyle that contribute to obesity and diabetes are likely at least partly to blame, said lead author Brett M. Kissela, MD, associate professor, codirector of the Neurology Residency Program, and vice-chair of Education and Clinical Services at the University of Cincinnati Neuroscience Institute in Ohio.

Dr. Brett Kissela

"The simplistic way to think of this is that stroke is the end result of not taking care of risk factors over time, so this is a reason why we should be more concerned about the epidemic of obesity and diabetes," Dr. Kissela told Medscape Neurology.

For the study, researchers examined data from the Greater Cincinnati/Northern Kentucky region, which includes 5 counties with a total population of about 1.3 million. The region is representative of the United States in terms of age, percentage of African Americans, and income and education levels.

Stroke-Related Data

For 3 periods (1993-1994, 1999, and 2005), the researchers gathered stroke-related data from discharge diagnoses, medical reviews, and a sampling of nursing homes and physician offices. They determined the mean age of stroke and rates of stroke by race, age, and stroke subtype.

They found that the mean (SD) age for a stroke in 1993-1994 was 71.3 (13.6) years, but this decreased to 70.9 (14.1) years in 1999 and to 68.4 (15.4) years in 2005 (P < .0001).

The reduction in the number of strokes among older people could be due to better treatment and stroke prevention initiatives, the study authors speculate. "We've seen significant improvement in the weapons at our disposal to treat risk factors," said Dr. Kissela. "My hope is that this is a result of people being aware of risk factors, treating them aggressively and preventing strokes."

But younger patients do not appear to be heeding the message. In patients younger than 45 years, the percentage of strokes went from 4.5% in 1993-1994 to 5.5% in 1999 to 7.3% in 2005.

Racial Differences

The researchers found racial differences in stroke incidence. Among blacks older than 85 years, the incidence decreased significantly — from 1910 per 100,000 in 1993-1994 to 1029 per 100,000 in 2005. But for whites, the incidence began to decrease significantly earlier. During the same period, the incidence of stroke in those aged 65 to 74 years decreased from 530 per 100,000 to 451 per 100,000, among those aged 75 to 84 years it decreased from 1039 to 778 per 100,000, and for those 85 years and older it decreased from 1680 to 1263 per 100,000.

There were also racial differences in stroke incidence in the younger age group. Although the incidence rates for strokes in 20- to 45-year-olds increased in both blacks and whites, the increase was only statistically significant among whites, doubling from 12 per 100,000 people to 25 per 100,000.

In those aged 20 to 44 years, the percentage of strokes that were due to infarct increased significantly from 56% in 1993-1994 to 66% in 2005, the study found.

Although a younger person who has a stroke has a greater chance of recovering full function than an older patient, a stroke at any age can be devastating, commented Dr. Kissela.

"Age is an important prognostic factor after a stroke, but certainly this is not trivial at any age," he said. "People can be disabled and unable to work, unable to do things they would like to do at a younger age, like hold their children or grandchildren."

Dr. Kissela said it is very important for physicians to work together with patients, including younger ones, to modify any risk factors for stroke. "Stroke is a life-changing, devastating disease. It can affect young people, and we hope these data will serve as a wake-up call."

Very Concerning

Approached for a comment, Brian Silver, MD, a stroke neurologist at Henry Ford Hospital in Detroit, Michigan, said the study was "obviously very concerning."

"I think we have been focusing so much of our energy on the older population groups that perhaps what slipped from our radar was the fact that these younger patients were vulnerable," he told Medscape Neurology.

Although it used to be almost unheard of for patients younger than 50 years to have a stroke, now it is not at all uncommon, he said. "In the last 2 or 3 weeks, I can think of 4 or 5 patients in their 30s and 40s who I’ve seen with a stroke."

He said the decrease in average age for a stroke is likely not confined to Cincinnati and Kentucky but probably applies right across North America. And he agreed that the mechanism underlying this decrease is probably the rising rates of obesity, diabetes, and hypertension.

"The change has occurred in just over a decade, so that would rule out some freak genetic change in the population," he said.

Some experts predict that diseases related to obesity will essentially erase all the health gains made by the reduction in cigarette smoking, said Dr. Silver.

"If that hypothesis is true, what you would want to do is encourage people at a very young age, be they in elementary school or high school, to adopt a healthy lifestyle, which includes regular physical activity and better food choices," he said. "A lot of it may have to do with spending too much time with computer games and videos and eating fast foods as opposed to going out and playing hockey, baseball, and having a sensible meal afterwards."

The study authors have disclosed no relevant financial relationships.

International Stroke Conference (ISC) 2010: Abstract 83. Presented February 24, 2010.