THURSDAY, Aug. 4, 2005 (HealthDay News) -- Even a little bit of high blood pressure increases your risk of heart attack and cardiovascular disease, a new study confirms.
People with blood pressure slightly above the recommended level but not high enough to be classified as having hypertension -- the medical name for high blood pressure -- are three times more likely to have a heart attack and 1.7 times more likely to have heart disease, the study found.
These people have "prehypertension," a category created about a year ago by the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure.
The study, by physicians at the University of Medicine and Dentistry of New Jersey, appears in the Aug. 5 issue of Stroke.
Normal blood pressure is defined as a reading lower than 120 over 80 millimeters of mercury -- the higher number when the heart contracts, the lower number when it releases. Hypertension is defined as a reading higher than 140 over 90. The higher number, systolic blood pressure, is regarded as more important.
The New Jersey researchers looked at more than 5,000 participants in the Framingham Heart Study who fell into the in-between category for a follow-up period of 10 years.
Curiously, no increased risk of stroke was found for the prehypertensive participants. "This is somewhat surprising, but it may be related to the small number of stroke events in the study," wrote Dr. Adnan I. Qureshi, a professor of medicine at the university.
That is probably the case, said Dr. Daniel Jones, vice chancellor for health affairs at the University of Mississippi Medical Center, and a spokesman for the American Heart Association, since the recommendation for treatment of prehypertension was based on studies showing an increased risk of heart disease and stroke.
The need to pay attention to prehypertension "has been embraced generally" by doctors, Jones said. The recommended measures are aimed at lifestyle changes -- weight reduction if someone is overweight, regular exercise, avoidance of smoking, a diet high in fruits and vegetables.
The drug treatment that is normal for hypertension is not used in this case "with rare exceptions," such as people with diabetes or chronic kidney disease, Jones said. "While we have known for years that the risk is present, we don't know for most people in this group whether drug therapy will reduce that risk, because drug therapy can have risks of its own," he said.
But the new findings "raise the question of whether we should treat prehypertensive patients more aggressively," Qureshi wrote.
It is important that people know about prehypertension and its treatment, because an estimated 55 million Americans have the condition, the researchers said.
The basics of hypertension and prehypertension are explained by the National Heart, Lung, and Blood Institute.