These are the millions of Americans with blood pressure above the 120/80 regarded as the upper limit of normal but below the reading of 140/90 that is the borderline of hypertension, the level at which treatment is urgently recommended.
Now a study funded by the National Heart, Lung and Blood Institute finds that people in this high-normal range have a 1.5 to 2.5 times greater risk of suffering a heart attack, stroke or heart failure in 10 years than those with optimal blood pressure.The results "are not totally unexpected, because it has been previously demonstrated in other studies that there is a continuum of risk that begins at 120 over 80," says Dr. Ramachandran Vasan, associate professor of medicine at Boston University School of Medicine and lead author of a paper in the Nov. 1 New England Journal of Medicine.
And the study "lends support to current recommendations that in persons with high blood pressure, lifestyle-related measures should be taken to lower blood pressure to normal levels," Vasan adds. Those measures include weight loss for the obese, regular exercise for the inactive, and a diet that is low in salt and fat and high in fruits and vegetables.
But the study was not designed to say whether people with high-normal blood pressure would benefit from the medications prescribed for those with hypertension, Vasan says.
The report used data on almost 7,000 participants in the long-running Framingham Heart Study. At the start of the study, about a quarter of them had blood pressure readings in the high-normal range. Over the next 10 years, the rate of cardiovascular events -- heart attack, stroke, heart failure -- was 2.8 percent in women with normal blood pressure and 4.4 percent for high-normal women. For high-normal men, the rate was 10.1 percent, compared to 7.6 percent for those with normal blood pressure.
"This raises the question of whether we should be treating these patients differently," says Dr. Alberto Nasjletti, a pharmacology professor at New York Medical College and chairman of the American Heart Association council on high blood pressure research. "It may be that we should lower the levels which we consider, to separate those with normal blood pressure from those with high blood pressure. Many who we consider to be high-normal are actually hypertensive."
It's possible for lifestyle changes to bring people's blood pressure down from the high-normal range to a safer level, Nasjletti adds. Losing weight, getting moderate physical exercise, controlling intake of salt and lowering blood cholesterol levels have been shown to work, he says. But "these are not easy to do," Nasjletti says. "It is easy to say, 'Do it,' but it requires a great deal of education."
So the report offers "a compelling reason for further studies to se how we can reduce the risk," he adds. "This is important, because there are a very large number of people walking around with blood pressure in the high-normal range."
About 13 percent of all Americans are estimated to have high-normal blood pressure.
"This is a very large segment of the population," Nasjletti says. "And it is clear that the lower the blood pressure, the lower the cardiovascular risk and the longer the life span."
What To Do
If you don't know your blood pressure, you should learn what it is, and if it is higher than 120/80, talk to a doctor about measures to bring it down to a safer level.