In people older than 65, researchers believe other factors obscure the impact of prehypertension. "Age is such a powerful factor putting people at risk of stroke that we think it overwhelms any added contribution from the slightly higher blood pressure," Ovbiagele said.
The study is published in the Sept. 28 online edition and the Oct. 4 print issue of the journal Neurology.
Between 25 percent and 46 percent of the study participants were prehypertensive. Prior research has found that about 25 percent of U.S. adults have prehypertension, according to background information in an accompanying editorial.
Experts said it was premature to suggest that everyone with slightly elevated blood pressure be put on medications.
Instead, current recommendations call for people with prehypertension to make changes such as quitting smoking, exercising at least 30 minutes daily, limiting alcohol, reducing salt intake, and maintaining a normal body mass index.
Medications are recommended when lifestyle changes fail to bring down blood pressure, and in people with diabetes or kidney disease, said Dr. Amytis Towfighi, an assistant professor of neurology at University of Southern California's Keck School of Medicine, who co-wrote the accompanying editorial.
"Lifestyle changes have been shown to lower blood pressure in individuals with prehypertension," Towfighi said.
The American Academy of Family Physicians has tips on lowering high blood pressure.
SOURCES: Bruce Ovbiagele, M.D., professor, neurosciences, University of California, San Diego; Amytis Towfighi, M.D., assistant professor, neurolog
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