A mixed bag of news from a new study in The New England Journal of Medicine: The number of strokes in the U.S. has edged downward over the past 50 years, but the overall lifetime risk has not declined at the same rate.
Researchers at Boston University School of Medicine examined data on more than 9,000 participants in the Framingham Heart Study, the largest and longest-running study of cardiovascular disease and risk.
The researchers observed several positive trends: improved mean systolic blood pressure and cholesterol levels, less hypertension, and fewer smokers. But the news was less sanguine on other risk factors for stroke-with increased prevalence of diabetes in women, atrial fibrillation in men, and a higher mean body mass index for both sexes.
The severity of stroke has not decreased and 30-day mortality has decreased only in men, says neurologist and lead researcher Ralph Carandang, M.D. That could be because men are older when they have strokes, and women experience more severe strokes.
These sobering trends emphasize that while improved control of risk factors has lowered incidence of stroke, there is a need for greater primary prevention efforts to reduce lifetime risk, severity, and 30-day mortality following stroke, he says.