I bet a lot of people jumped to conclusions when the U.S. Centers for Disease Control and Prevention (CDC) announced that hospitalizations of some young people for acute ischemic stroke increased by as much as 53% between 1994-1995 and 2006-2007. I know that the first thought crossing my mind was, “Blame the obesity epidemic.”
But it’s not that simple, and the story illustrates the many nuances of interpreting medical and epidemiologic studies. For one thing, note that the CDC studied hospitalization rates, not stroke rates, so the study isn’t necessarily saying that young people are having more strokes. You can’t make that assumption. Other factors may have led to more hospitalizations.
Also, hospitalizations for stroke increased or decreased in different age groups, Dr. Mary G. George of the CDC and her associates reported at the International Stroke Conference. That led some physicians at the meeting to pat themselves on the back, believing that their efforts helped decrease stroke hospitalizations in adults aged 45-64 or 65 and older, while others scratched their heads over increased stroke hospitalizations in three younger age groups: 5-14 years; 15-34 years, and 35-44 years. The youngest age group diverged by sex, with a decrease in stroke hospitalizations in females and no significant change in males aged 0-4 years.
As alarming as it sounds to hear that more teenagers and young adults are being hospitalized for stroke, it’s important to keep in mind that these are still rare. For example, the biggest increase in stroke hospitalizations — a 53% jump — was seen in young men aged 15-34 years. But in absolute terms, only 15 of every 10,000 men in that age group who were hospitalized in 2006-2007 had acute ischemic strokes.
I certainly don’t mean to dismiss concerns about the obesity epidemic and other risk factors for stroke such as hypertension and diabetes, or about increased stroke hospitalizations in some age groups. But Dr. Lee H. Schwamm, director of telestroke and acute stroke services at Massachusetts General Hospital, Boston, explained how these are unlikely to be the cause of increased stroke hospitalizations in young people. Listen to this podcast with Dr. Schwamm, created from interviews released by the American Heart Association and American Stroke, which sponsored the meeting.
Whatever factors may be responsible for increased stroke hospitalizations in young people, we’ve still got to decrease the traditional risk factors for stroke (obesity, hypertension, diabetes), he emphasized, “otherwise we will have a wave of cardiovascular disease and stroke in the next 20-30 years.”
— Sherry Boschert (@sherryboschert)