The study, which was presented at the American Stroke Association’s International Stroke Conference, found that those who live in the Stroke Belt — which includes Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee — when they are middle-aged and older, but lived somewhere else as a child or young adult, are not as likely to develop cognitive impairment.
“Compared to people who did not spend any of their young life in the Stroke Belt, people who spent all of their young life in the Stroke Belt, but currently live outside of it, had higher risk of cognitive impairment in older life,” said Virginia Howard, Ph.D., lead author of the study and a professor of epidemiology at the UAB School of Public Health. “For people who currently live in the Stroke Belt, compared to people who spent all of their young life in the Stroke Belt, their risk of having cognitive impairment later in life is less if they spent some or all of their early adulthood outside of the Stroke Belt.”
Researchers compared nearly 11,500 people living in the Stroke Belt with nearly 9,000 people living outside of it. All of the participants are part of the Reasons for Geographic and Racial Differences in Stroke, or REGARDS, study, a federally funded study based at UAB.
“Risk factors for both stroke and cognitive decline, such as smoking and high blood pressure, may be more common in the Stroke Belt than elsewhere in the country — even in children and young adults,” Howard explained.
Those who spent all of their childhood outside of the Stroke Belt were 24 percent less likely to develop cognitive impairment, compared to those who were lifelong residents. People who spent all of their early adulthood, between ages 19 and 30 years old, outside of the Stroke Belt were 30 percent less likely to develop cognitive impairment.
“These findings suggest that early residence in the Stroke Belt during childhood or early adulthood may increase the risk of cognitive impairment, no matter where you live in later adulthood,” Howard explained. “As other research studies are also finding, this study suggests that attention should be paid to managing risk factors earlier in life, toward prevention of cognitive decline.”
Researchers also found that there was no difference in risk of cognitive impairment in those who spent all or part of their childhood, or some but not all of their young adulthood, within the Stroke Belt.
The other co-authors are George Howard, DrPH, Michael Crowe, Ph.D., Aleena Bennett, M.S., and Virginia Wadley, Ph.D., all of UAB; Jennifer Manly, Ph.D., Columbia University; M. Maria Glymour, Sc.D., University of California–San Francisco; Laura Zahodne, Ph.D., University of Michigan; Leslie McClure, Ph.D., Drexel University; Frederick Unverzagt, Ph.D., Indiana University.