Researchers say they found that high systolic pressure -- the blood pressure when the heart contracts -- is a significant risk factor for cardiovascular disease and its complications in middle-aged and older women.
Doctors say 36% of serious cardiovascular events such as heart attacks and strokes are preventable by lowering blood pressure in women, compared to only 24% in men.
For the study, investigators examined data on 9,357 adults in 11 countries in Europe, Asia, and South America for a median of 11 years. The researchers looked for absolute and relative risks of cardiovascular disease that were associated with systolic blood pressure.
They report that three major risk factors account for 85% of the modifiable risk for heart disease in men and women -- high systolic (the top number) blood pressure, high cholesterol, and smoking. And high systolic pressure is the most important risk factor, according to the researchers.
“I was surprised by the study findings that highlight the missed opportunities for prevention of heart disease in older women,” researcher Jan A. Staessen, MD, PhD, of the University of Leuven in Belgium, says in a news release.
He says the research team found that a relatively small increase of 15 points in systolic blood pressure increased the risk of cardiovascular disease by 56% in women and 32% in men.
For the study, the researchers looked at ambulatory blood pressure, which involves measuring blood pressure at set intervals for 24 hours during a person’s daily routine and when asleep, and conventional blood pressure readings taken in doctors’ offices.
The researchers say ambulatory blood pressure readings have less potential for error and provide more accurate estimates of usual blood pressure and prognosis for cardiovascular disease.
The monitor used for ambulatory readings was a small, portable device programmed to take blood pressures at specific intervals. In the study, ambulatory readings were taken at intervals of 15 to 30 minutes during the daytime, and 30 to 45 minutes at night.
Nighttime readings are a better predictor of heart disease than daytime readings because the readings taken at night are more standardized, the researchers say. And blood pressure at night is less likely to be influenced by physical activity.
Quality of Life
“It is recognized that women live longer than men, but that older women usually report lower quality of life than men,” Staessen says. “By lowering systolic pressure by 15 [points] in hypertensive women, there would be an increased benefit in quality of life by prevention of cardiovascular disease.”
The researchers say that women and their doctors ought to become more aggressive in diagnosing and treating high systolic blood pressure.
The study is published in Hypertension: Journal of the American Heart Association.