While cultural pundits are worried about the health impact of obesity and which foods need to be more regulated to prevent chronic disease, a new analysis has found that incidents of ischemic stroke, the most common type of stroke caused by a clot in the blood vessels of the brain, has declined among most during the past decade. 

Whites and Hispanics/Latinos, the largest minority group in the U.S. with 17 percent of the population, saw similar declines. However, since Mexican-Americans are projected to be 30 percent of the US population by 2050, their higher rate of stroke is still a concern, despite the decrease. Mexican-Americans have 34 percent more stroke risk than non-Hispanic whites. Since the cost cost of stroke for the first half of this century in the U.S. could amount to more than $1.5 trillion dollars, lower stroke incidence could be a good thing for taxpayers.

"In minority groups stroke occurs at much younger ages, often resulting in greater disability and significantly higher costs," says lead study author Lewis B. Morgenstern, M.D., Director of the Stroke Program at the University of Michigan Health System. "With stroke causing such a personal, family and economic burden in minorities, our study focuses on Mexican Americans -- one of the largest and fastest growing segments of the U.S. population."

The results came from  the project Brain Attack Surveillance in Corpus Christi (BASIC), the only ongoing stroke surveillance project focusing on Mexican Americans. Since 2000, every stroke occurring in those age 45 and older living in Nueces County, Texas, has been counted and analyzed. BASIC is led by the University of Michigan Frankel Cardiovascular Center where researchers collaborate with a neurologist and study staff based in Corpus Christi. Together they examine the biological and social risk factors for stroke among Mexican Americans, information that may help reduce strokes and improve stroke care across the country. 

Dr. Lewis Morgenstern, neurologist at the University of Michigan Frankel Cardiovascular Center, describes the work underway to reduce strokes among Mexican Americans, one of the largest and fastest growing segments of the U.S. population. Credit: University of Michigan Health System 

Two-thirds of those in the study were Mexican American and the remainder primarily non-Hispanic White, with 87 percent born in the U.S., 11 percent in Mexico, and 1 percent who did not know their country of birth. Those born in Mexico have lived in the U.S. an average of 52 years.

Results show ischemic stroke occurred in 2,604 Mexican Americans and 2,042 non-Hispanic Whites, representing a 36 percent decline for the study period, 2000-2010.

Analysis found that the decline was limited to those 60 years of age and over and was evident in both ethnic populations. The disparity between Mexican American and non-Hispanic White stroke rates in those 45-74 years of age is unchanged.

"The dramatic decline in stroke rates during the last decade is encouraging," says Morgenstern, a professor of neurology, emergency medicine and neurosurgery at the U-M Medical School and professor of epidemiology at the U-M School of Public Health.

"However, the ongoing disparity among younger patients emphasizes the need for further interventions to prevent stroke, particularly among young Mexican Americans," he says. 

Citation: Morgenstern, L. B., Smith, M. A., Sánchez, B. N., Brown, D. L., Zahuranec, D. B., Garcia, N., Kerber, K. A., Skolarus, L. E., Meurer, W. J., Burke, J. F., Adelman, E. E., Baek, J. and Lisabeth, L. D. , 'Persistent Ischemic stroke disparities despite declining incidence in mexican americans', Ann Neurol., n/a. doi: 10.1002/ana.23972