Higher Wealth Linked to Lower Risk of Early StrokePosted: Updated:
Wealthy Americans have a lower risk of stroke between the ages of 50 and 64, according to the data on the almost 20,000 participants in the ongoing University of Michigan Health and Retirement Study.
And the most probable reason why the difference vanishes at the age of 65 is that more of the poorer, more vulnerable, people have already died off, said study author Mauricio Avendano, a research fellow at the Erasmus Medical Center in the Netherlands. The report was published in the April 24 issue of Stroke.
Of the 780,000 Americans who are struck by new or recurrent strokes each year, 27 percent are under 65, according to the American Heart Association.
Avendano and his fellow researcher, M. Maria Glymour of the Harvard School of Public Health, examined the possibility that a later beneficial effect comes from the full health coverage provided by Medicare after age 65.
"It is possible that because more people have care, the differences between the wealthy and others doesn't matter as much," Avendano said. "But this is not a good explanation. We tend to think it is more an effect of what we call selective survival. There is a selection of people who reach age 65. People with low incomes are more likely to die, so when you reach age 65, you have a selected group of very healthy people."
This is the first study to assess the age patterns of wealth, income and education in stroke incidence in older Americans, he said, and also the first to report that economic status predicts stroke risk.
Many earlier reports have linked lower socioeconomic status with an increased risk of stroke. This one draws a distinction between wealth, defined as the total of all financial and housing assets minus liabilities, and high income, but it is not much of a distinction, Avendano said.
"If you are born into a rich family, it doesn't matter whether you have a high income," he said. "You have a lower risk of stroke."
The study divided the participants into six groups, based on their wealth. They zeroed in on those in the fifth highest group, leaving out the rich and ultra rich. The people in that group, formally those in the 75th to 89th percentile, had one-third the risk of a stroke between 50 and 64 of the 10 percent with the lowest wealth.
Not surprisingly, the study found that lower income, wealth and education was associated with a higher incidence of smoking, low physical activity, diabetes and high blood pressure, all major risk factors for stroke.
Education didn't matter much in terms of stroke risk, either before or after age 65.
The public health application of the finding is that giving more money to poor people could reduce their risk of early stroke, Avendano said. But, as he noted in a statement, "diminishing wealth inequality requires transforming structural policies beyond the health-care system that aim to redistribute income and wealth to benefit the most disadvantaged members of society."
The report "didn't surprise me much, but just a little bit," said Dr. Claudette Brooks, an assistant professor of neurology at West Virginia University.
"We know that the risk of stroke increases after age 65, but there are other factors at work," she said.
Risk factors for stroke other than lack of money are described by the American Heart Association.
SOURCES: Mauricio Avendano, Ph.D., research fellow, Erasmus Medical Center, Rotterdam, the Netherlands; Claudette Brooks, M.D., assistant professor, neurology, West Virginia University, Morgantown; April 25, 2008, Stroke