The number of acute ischemic stroke hospitalizations among middle-aged and older men and women fell between 1994 and 2007, but sharply increased among those under age 35—including teens and children—according to research presented at the American Stroke Association's International Stroke Conference 2011 in Los Angeles.
Xin Tong, MPH, and colleagues from the U.S. Centers for Disease Control and Prevention (CDC), noted that there is limited information on population-based estimates of trends in acute ischemic stroke hospitalizations by age and gender.
They identified acute ischemic stroke hospitalizations with the primary diagnosis of ICD-9-CM codes. The study population consisted of 1994 to 2007 hospitalizations from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project. Seven consecutive two-year time intervals were selected in this study.
During the study period, the researchers identified declining rates of 51 percent in girls zero to four years and 25 percent in men and 29 percent in women older than 45.
However, the number of ischemic stroke hospitalizations increased 51 percent in males between ages 15 and 34 during the period studied. The rate increased 17 percent in females between 15 and 34.
Among children and teens, they found a 31 percent increase in boys between five to 14 years and a 36 percent increase among girls five to 14 years. In fact, the largest increase found in the study from 9.8 per 10,000 hospitalizations in 1994 to 1995 to 14.8 per 10,000 hospitalizations in 2006 to 2007 was observed among males aged 15 to 34.
Among the younger middle-aged set, they found a 47 percent increase among men 35 to 44 years and a 36 percent increase among women 35 to 44 years.
The researchers concluded that results from national surveillance data punctuate the need to further investigate socio-demographic, clinical and healthcare factors associated with the recent increase in acute ischemic stroke hospitalizations among the younger population.
"We cannot link anything in particular to the trend in younger patients, but I believe the role of obesity and hypertension will prompt a big discussion. Unfortunately, right now we can't speculate on the causes," said Tong, a health statistician with the CDC's Division for Heart Disease and Stroke Prevention in Atlanta.
However, hospitals and physicians should be aware of the rising risk of stroke in young people, and the necessity to educate them about stroke symptoms, Tong said.
"Acute ischemic stroke is currently considered something that mostly happens to older people, but awareness of rising rates in the young is important or else tPA and other important stroke treatment may be unnecessarily delayed in younger patients," she said.
Tong said her group is pursuing additional investigation on this subject.
This study did not receive any funding support.