Map Redraws 'Stroke Belt'
Oregon, Washington edge out traditional southern states, says study
WEDNESDAY, Oct. 4, 2001 (HealthDayNews) -- The "Stroke Belt" has been hiked up a notch or two. You're now more likely to die from a stroke if you live in Oregon or Washington than if you live in some southeast states that used to have the highest risk, says new research.
A study published in the October issue of Stroke: Journal of the American Heart Association examined stroke mortality data from the National Center for Health Statistics from 1968 through 1996.
Deaths from various types of stroke went down 60 percent nationally in those years and were thought to have leveled off. The researchers wanted to see if the plateau was uniform and how the decline varied across regions, races and genders. The result, conveyed through a statistician's dream world of figures, formulas and charts, is an entirely new portrait of stroke mortality across the United States.
Around 1968, stroke mortality rates were about 40 percent higher than the national average in the so-called "Stroke Belt," including North Carolina, South Carolina, Georgia, Alabama, Mississippi, Arkansas, Tennessee and Louisiana. Now it looks as if Mississippi and Alabama, where stroke death rates declined 60 percent for women and more than 65 percent for men, are being edged out by Washington and Oregon, where declines were less -- about 55 percent for women and 60 percent for men.
Furthermore, rates in Oregon, Washington and Arkansas seem to be leveling out, whereas rates in Mississippi and Alabama continue to drop. "Alabama used to be the gut of the Stroke Belt, and the rate just dropped out of the bottom. It's one of the greatest declines, and nobody knows why," says lead study author George Howard, professor and chairman of the department of biostatistics at the University of Alabama at Birmingham.
The coastal plains of North Carolina, South Carolina and Georgia -- known as the "buckle" of the Stroke Belt because the stroke-death rate is about double that of the rest of the country -- experienced a smaller decline than most other areas and still have the highest stroke mortality.
Surprisingly, New York City and southern Florida, two states that started with the lowest stroke mortality rates, have fallen the furthest and are still declining. "This is exactly what you would not expect," says Howard. "You would expect areas that are high to decrease the furthest because they have further to go. The horse that was in first place outran everybody and is still speeding up."
The decline in stroke deaths appears to be greatest among white men and least among black men, although both groups are declining. "It looks like whites have slowed in their rate, but African-Americans still seem to be decreasing and this is fairly major good news," says Howard. The gap between whites and blacks is narrowing slightly but isn't likely to close for decades, he says. Currently, blacks generally have about a 40 percent higher risk of dying from stroke than whites; blacks ages 45 to 65 have a four-fold greater risk.
Howard says the differences between men and women weren't that great. "Men carry about 25 percent excess over women, and that seems like it will persist," says Howard, although he says forecasting that is a little like predicting the weather -- "always a dangerous game."
No one really knows why the patterns are as they are. "The two great mysteries in stroke epidemiology is why more people in the south and why more African-Americans die," says Howard, who just received a grant from the National Institute of Neurological Disorders and Stroke to examine these and other "whys."
Other experts say just because the overall picture is brighter doesn't mean we should stop paying attention to preventing and treating stroke. "There are still a lot of modifiable stroke risk factors and just because one may be controlled or targeted, there are others that can still be targeted to decrease the risk," says Dr. Richard T. Benson, a stroke neurologist at Long Island Jewish Medical Center in Hyde Park, N.Y. "Blood pressure is one thing; diet, physical activity, smoking, heavy alcohol consumption and socioeconomic status are all factors."
"It does look like mortality may have leveled off. but I don't think that's an excuse for not trying to improve things further," says Dr. Dana Leifer, chief of vascular neurology and director of the stroke unit at North Shore Hospital in Manhasset, N.Y., and associate professor of neurology at New York University School of Medicine. "Risk factors need to be treated even more rigorously, and I think there's still a lot of room to improve treatment -- both getting people to the hospital more quickly for existing treatment and new treatments that are currently under development. This may significantly reduce mortality in the future."
What To Do: To learn more about stroke, visit the National Stroke Association, the American Heart Association or the National Institute of Neurological Disorders and Stroke.