Higher Cognitive Decline Risk for Stroke Belt Residents
Similar regional pattern seen in southern U.S. for stroke risk and cognitive impairment
THURSDAY, June 9 (HealthDay News) -- Regional differences seen for stroke mortality in the United States are also seen for cognitive decline, according to a study published online May 26 in the Annals of Neurology.
Virginia S. Wadley, Ph.D., from the University of Alabama at Birmingham, and colleagues investigated whether the incidence of impaired cognitive screening is higher in the southern Stroke Belt region of the United States compared to that in the rest of the country. A cohort of 23,913 adults aged 45 or older were included in the Reasons for Geographic and Racial Differences in Stroke study conducted from 2003 to 2007. The global cognitive status of participants who had no history of stroke, and who were cognitively intact at baseline, was evaluated annually by telephone with the Six-Item Screener (SIS) and every two years with fluency and recall tasks during an average 4.1-year follow-up. Stroke Belt residents comprised 56 percent of the study participants. Regional differences in incident cognitive impairment (defined as an SIS score of four or lower) were adjusted for demographic factors and the time between the first and last evaluations.
The investigators found that, at the most recent evaluation, 8.1 percent of participants had declined to an SIS score of four or lower. Compared to non-belt residents, those residing in the Stroke Belt had increased adjusted odds of incident cognitive impairment (odds ratio, 1.18). Cognitive impairment was independently predicted by demographic factors and time.
"This study is the first known documentation of higher incident cognitive impairment in the Stroke Belt region of the United States than in the rest of the nation," the authors write.
One of the authors disclosed financial ties to a pharmaceutical company.