Prehypertension Is 'On The Map' Of Cardiovascular Risk Factors

Using the most recent definitions for hypertension, normal blood pressure is systolic pressure (the top number in a blood pressure reading) less than 120 mm Hg and diastolic (bottom number) less than 80 mm Hg; prehypertension is systolic pressure of 120-139 or diastolic 80-89 mm Hg; and hypertension is systolic pressure of 140 mm Hg or higher, or diastolic pressure of 90 mm Hg or higher or currently taking antihypertensive medication.

"Is the cardiovascular risk with blood pressures slightly above 120/80 mm Hg clinically important enough to justify the label of prehypertension?" asked the authors of the study, published in Circulation: Journal of the American Heart Association. "The increased cardiovascular risk with prehypertension is certainly smaller than the risk associated with having diabetes (158 percent higher risk), but is greater than that associated with smoking (34 percent higher). Since smoking is pretty much unchallenged as a cardiovascular risk factor, perhaps prehypertension should be afforded the same acceptance."

Researchers studied 60,785 postmenopausal women in the Women's Health Initiative during a 7.7-year follow-up. At the start of the study, 26 percent had normal blood pressure, 39 percent had prehypertension and 35 percent had hypertension. Prehypertension rates among women of different ethnic groups were 39.5 percent for whites, 32.1 for blacks, 42.6 for Hispanics, 38.7 for American Indians and 40.3 percent for Asians.

Women with higher blood pressures were more likely to be older, have higher body mass index, diabetes or high cholesterol. Smoking was more common among women with normal blood pressure (10 percent).

The 10-year incidence of cardiovascular events was 3.63 percent for women with normal blood pressure, 7.11 percent for women with prehypertension; and 14.16 percent for women with high blood pressure.

Compared to women with normal blood pressure, prehypertensive women of any ethnicity had a 58 percent higher risk of cardiovascular death: 76 percent higher risk of heart attack; 93 percent higher risk of stroke; 36 percent higher risk for being hospitalized with heart failure; and 66 percent higher risk for any cardiovascular event. Even after adjusting for age, body mass index, diabetes, high cholesterol and smoking status, prehypertension was independently associated with a higher risk of cardiovascular events.