While one-third of Americans suffer from full-blown high blood pressure, Laura Landro of The Wall Street Journal reports that an additional 37 percent of the U.S. population may have prehypertension — a classification devised in 2003 by medical experts that includes what was once considered to be “normal to high normal” levels (blood pressure between 120 and 139 mm Hg systolic and 80 to 89 mm Hg diastolic).
ACSH's Dr. Gilbert Ross explains that blood pressure is a risk continuum, and there is no bright line that differentiates between normal and high levels. “When I was in practice many years ago, physicians were happy with a reading of 130/80, but now people with these levels are considered to be at some risk for hypertension-related complications.”
What concerns ACSH's Dr. Elizabeth Whelan is that these new hypertension subcategories may not be widely accepted or even understood by physicians. “How many doctors know about this and would prescribe a patient blood-pressure lowering drugs for prehypertension?"
Dr. Ross defers to the recommendation issued by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, which does not promote an official drug treatment regimen, but instead suggests that prehypertension patients lose weight and exercise to reduce elevated blood pressure levels. “I wouldn’t advocate putting someone with prehypertension on drugs without first addressing lifestyle factors. Patients with mild- or prehypertension who lose 10 to 15 pounds usually do not require any further treatment. Of course for those non-overweight patients, I would probably prescribe them a low dose of hydrochlorothiazide — a mild blood pressure medication that is generally quite safe and effective.” Dr. Ross warns, however, that when using drugs to treat mildly elevated blood pressure, you always have to be careful to ensure that you don’t reduce it too much, otherwise patients can experience light-headedness or dizziness.
According to Dr. George Bakris, director of the Hypertension Center at the University of Chicago, cardiovascular risks begin to increase at blood pressure readings as low as 115/75, and the risk doubles for each successive 20 mm Hg increase in systolic pressure and 10 mm Hg increase in diastolic pressure.
But Dr. Whelan maintains that these figures may be poorly understood because blood pressure can vary so much, even throughout a single day, which is why many doctors recommend that such patients purchase a home blood-pressure monitor — many are available and are simple to use — and that they keep a log of their readings every morning and evening.
“Hypertension is a silent killer and is a risk factor for heart disease, kidney disease, and stroke,” says Dr. Ross. “It is significantly underdiagnosed and undertreated. With the exception of smoking cessation, treating hypertension has the possibility to save more lives in the United States than any other public health intervention.”