Advancing age has long been considered a major risk factor for stroke. But research published Thursday morning shows that, even as stroke incidence among older people has leveled off in recent years, the incidence of stroke-related hospitalization among teens and young adults has risen.

A study conducted by researchers at the U.S. Centers for Disease Control and Prevention and published online today in the journal Annals of Neurology finds that hospitalizations for ischemic stroke (which occurs when a blood vessel supplying the brain is blocked by a clot or by a build-up of fatty deposits called plaque) rose by about 37 percent among people ages 15 to 44 between 1995 and 2008.

Ischemic stroke is the most common form of stroke, accounting for close to 90 percent of all cases of stroke, according to the American Heart Association.

In its introduction, the study notes that stroke among children and young adults accounts for between 5 percent and 10 percent of all strokes, adding that stroke is among the top 10 causes of childhood death.

The study also looked at the prevalence among young stroke victims of underlying conditions and lifestyle choices associated with stroke risk. Hypertension, diabetes, obesity, lipid disorders and tobacco use were among the most common conditions found among young people who’d been hospitalized for stroke, and the prevalence of those conditions rose from 1995 to 2008 among adolescents and young adults hospitalized with ischemic stroke. In particular, among young people hospitalized for ischemic stroke, almost a third of those ages 15 to 34 and more than half of those ages 35 to 44 had high blood pressure. A quarter of those ages 35 to 44 also had diabetes. And a quarter of females ages 15 to 34, a third of females ages 35 to 44, and a third of males ages 15 to 44 were tobacco users.

All of that points to a need to address those underlying conditions and lifestyle choices, the study suggests, in hopes of reversing stroke incidence among the young.