March 15, 2001 -- Nearly half of all adults in the U.S. who have high blood pressure aren't getting treated for it, and another third are getting inadequate therapy. What's more, most adults with uncontrolled high blood pressure, or hypertension, have a form of the disease that until recently has not been taken seriously enough.
An analysis of data from a nationwide health study shows that 65% of all people with uncontrolled hypertension have a form of high blood pressure called isolated systolic hypertension, in which their systolic blood pressure -- the first number in a blood pressure reading -- is abnormally high, but the diastolic pressure, or second number, is normal, write Stanley S. Franklin, MD, and colleagues in the March issue of the journal Hypertension: Journal of the American Heart Association.
High blood pressure that is not controlled can lead to heart attack, stroke, kidney failure, and other serious consequences. Doctors consider isolated systolic hypertension to be present when a patient's systolic pressure -- a measure of the heart at work -- is 140 mmHg (millimeters of mercury) or above, but the diastolic pressure -- a measure of the heart at rest -- is below 90 mmHg.
For most people, high blood pressure can be controlled through diet, exercise, and, when necessary, medication, but that message isn't getting through to enough doctors or their patients, suggests researcher Nathan D. Wong, PhD, in an interview with WebMD.
"As far as the public is concerned, we really need to pay much more careful attention to lifestyle changes. That's often not carefully enforced in people with high blood pressure," says Wong, an associate professor of cardiology and director of the heart disease prevention program at the University of California at Irvine.
"When we think of high cholesterol, we automatically think, 'Well, you've got to go on a low-fat diet and increase your fiber intake,' but we also know that one of the best ways to reduce high blood pressure ... is a diet high in vegetables and fruits and complex carbohydrates," he says.
But Franklin, a nephrologist and clinical professor of medicine at UCLA, says that drugs also will play a central role in most cases.
The researchers looked at data on the nearly 20,000 adults who took part in the National Health and Nutrition Examination Survey III (NHANES), a national study conducted from 1988 to 1994 in an attempt to provide estimates of common chronic diseases and the risk factors associated with them.
The authors scoured records for information about diastolic and systolic blood pressures by age in those who were under and over age 50. They also evaluated information about patient awareness of hypertension and its consequences for health.
They found that isolated systolic hypertension accounted for 65% of all cases of uncontrolled hypertension in the study group. In fact, isolated systolic hypertension accounted for 80% of such cases in subjects over age 50, and a whopping 87% of cases in those in their 60s and beyond.
"A lot of us have high normal blood pressure, and as we get older, the systolic [number] creeps upward and the diastolic creeps downward," Wong tells WebMD. "Certainly a lot of this is driven by our increase in body weight as we get older."
He says that although many physicians believe that getting a patient's blood pressure down to 140 over 90 or lower is enough, the optimal goal should be blood pressure lower than 120 over 80.
But achieving adequate pressures -- let alone the ideal -- can be a difficult task in itself, says Michael Alderman, MD, chairman of epidemiology at Albert Einstein College of Medicine in New York and a past president of the American Society of Hypertension.
Like Franklin, Alderman says that drug therapy is often required. "[M]ultiple drugs are almost always required to bring blood pressure down to the goal of less than 140 for all older folks," he tells WebMD. "Many of them also have diabetes, and the recommendations there are to lower blood pressure down to 130. That's very difficult to achieve in older people, and that's why it very often requires two or three antihypertensive [medications]."