U.S. stroke deaths have dramatically declined in the past several decades. But, researchers caution, their new study also found the potential for a resurgence.
“After nearly four decades of declining stroke-related mortality, the risk appears to be increasing in the United States. Our research underscores the need for novel strategies to combat this alarming trend,” said lead study author Cande Ananth. He is chief of epidemiology and biostatistics in the obstetrics, gynecology and reproductive sciences department at Rutgers Robert Wood Johnson Medical School in New Brunswick, N.J.
“This study didn't identify a cause for this trend, but other research suggests the main culprits are increasing rates of obesity and diabetes,” Ananth said in a Rutgers news release.
The analysis of U.S. stroke deaths from 1975 to 2019 found that stroke deaths plummeted from 88 per 100,000 for women to 31. They dropped from 112 per 100,000 to 39 for men.
Total stroke deaths fell despite the rise in age-adjusted risk because rates grow substantially with age.
Without further improvements in stroke prevention or treatment, the most recent figures show stroke death totals rising as millennials age. (Millennials were born roughly from the 1980s through 1990s.)
While age-adjusted stroke deaths per 100,000 people bottomed out in 2014, they climbed again during the study period's last five years.
“Starting around 1960, the later you were born, the higher your risk of suffering a fatal ischemic stroke at any particular age,” Ananth said.
For the study, the researchers used a comprehensive death-certificate database to identify virtually every adult under the age of 85 who died from a stroke during the 44 years of the study period. There were more than 4.3 million stroke deaths in all.
The investigators detected a steady rise in age-adjusted stroke risk from the late 1950s to the early 1990s.
The study also found that ischemic strokes have declined more than hemorrhagic strokes. In ischemic strokes, blood vessels to the brain are blocked. In hemorrhagic strokes, blood vessels leak or burst.
The fatality rate for ischemic strokes fell roughly 80%, compared to 65% for hemorrhagic strokes, the researchers noted.
Disparities between men and women diminished with age, the findings showed. While at age 55, men were more than twice as likely as women to have a fatal stroke, the rates were virtually identical at age 85.
The findings were recently published in the International Journal of Epidemiology.
The U.S. National Heart, Lung, and Blood Institute has more on stroke causes and risks.
SOURCE: Rutgers University, news release, Jan. 6, 2023