For example, middle-aged adults with the lowest 10% of wealth had about two times the risk of stroke compared with those in the 75th-89th percentile, which researchers say translates to the wealthy but not super-rich.
But the protective effect of wealth on stroke risk completely disappeared after age 65.
"We expected wealth to be a strong predictor of stroke in the elderly," researcher Mauricio Avendano, PhD, of the Erasmus Medical Center in Rotterdam, Netherlands, says in a news release. "We were surprised to see that it was not associated with stroke beyond age 65."
Wealth: A New Stroke Risk Factor?
Although previous studies have identified lower socioeconomic status as a risk factor for stroke, researchers say this is the first study to look at how factors that affect socioeconomic status, such as education, income, and overall wealth, evolve throughout middle and old age.
In their study, published in Stroke: Journal of the American Heart Association, researchers analyzed data from the Health and Retirement study, which followed a group of nearly 20,000 Americans aged 50 or older for an average of 8.5 years.
During the follow-up period, 1,542 participants had a stroke. The results showed that higher education reduced stroke risk at ages 50 to 64 but not after adjusting for wealth and income.
Both wealth and income were independent risk factors for stroke at ages 50 to 64. But wealth, including the total of all financial and housing assets minus the liabilities, was a much stronger risk factor, with increasing wealth linked to decreasing stroke risk.
"Wealth more comprehensively reflects both lifelong earnings and intergenerational transfers, and increases access to medical care and other material and psychosocial resources," Avendano says.
Beyond age 65, however, neither wealth, income, nor education was significant predictors of stroke risk.