New Rules of Blood Pressure
Establish Lower-Level Label

Government health officials raised a warning flag for millions of Americans who may be under the false impression that their blood-pressure levels are low enough to avert heart attacks, strokes and other consequences of hypertension.

Citing new evidence that blood-vessel damage begins at blood pressures now considered normal, the government's National Blood High Blood Pressure Education Program established a new category it calls "prehypertension" to help motivate people to take action early on to avoid later health problems. Researchers estimated that about 45 million Americans, or 22% of the adult population, fall into the category.

The new classification is part of broader set of guidelines issued Wednesday aimed at helping physicians and their patients better manage one of the most common problems in medicine. Slated for publication next week in the Journal of the American Medical Association, the recommendations call for more aggressive treatment with more medicines to help patients get their blood pressure under control.

But some of the new guidelines -- especially one calling on doctors to use cheap diuretics as the first-line treatment for most patients over newer, more expensive medicines -- drew immediate fire from several blood-pressure experts who believe that the advice is misguided.

More than 50 million Americans are estimated to have high blood pressure -- long defined and restated today as a level of 140/90. Despite years of public health efforts and pharmaceutical marketing of several classes of blood-pressure medicines, only 60% of people with high blood pressure are getting drugs, and only about 34% are even successfully treated.

The inability to improve that record is one reason experts deem it critical to address potential problems among the additional 45 million Americans now defined as prehypertensive. The guidelines cite recent evidence that the risk of cardiovascular disease begins to increase in patients with blood pressures above 115/75.

Moreover, the closer people are to actual hypertension, the more likely they will end up with the disease. For people between 40 and 70 years old, each 20-point increase in the higher, or systolic number, and 10-point rise in the diastolic number, doubles the risk of future heart attacks and strokes.

"We have to alert people who are on the way to 140 to do something to control it better," says Carlos Vallbona, professor of family and community medicine at Baylor College of Medicine, Houston.

For people who are prehypertensive, the guidelines don't recommend drugs, but instead, healthier living habits that can provide important benefits. For people who are overweight, losing 20 pounds can lower systolic pressure by 20 points, researchers say.

Brisk Walking

Regular aerobic exercise -- say, brisk walking 30 minutes a day -- can take four to nine points off the higher number, while limiting consumption of alcohol to two drinks a day for men and one for women trims an additional two to four points. (Each point represents a milligram of mercury used in measuring blood pressure.) Reducing the salt in your diet and adopting a diet of fruits, vegetables and low-fat dairy products is a boon for your blood pressure.

"This is a wake-up call for people to adopt healthy lifestyle changes to prevent the rise in blood pressure," says Ed Roccella, coordinator of the blood-pressure program, which is based at the National Heart, Lung and Blood Institute at the National Institutes of Health.

People at risk can use the new guidelines "to change their lifestyles now" to prevent high blood pressure -- one of the major contributors to heart attacks and strokes.

Despite the vast number of people suffering, the best treatment for high blood pressure is still widely debated. Doctors can now choose from at least six classes of drugs to treat the condition, and they vary widely over which is prescribed first, and which are added later.

Two significant changes in the new guidelines from the last version, published in 1997, have stirred the most debate. For most patients, diuretics alone are recommended first, instead of either a diuretic or a beta blocker -- a finding based on the results of a recent NIH-sponsored study.

Another recommendation urges doctors to attack stage 2 hypertension -- defined as 160/100 or higher, with two drugs immediately -- including a diuretic, rather than the current advice to start on one drug and add additional medicines as necessary. Both recommendations were challenged by some experts, who believe conclusions of the NIH study are overstated and biased.

John H. Laragh, a prominent hypertension researcher at New York Hospital/Cornell Medical Center, New York, says some patients have salt-sensitive hypertension who are likely to respond to diuretics but not drugs such as ACE inhibitors. Conversely, many patients whose blood pressure is affected by high levels of a hormone called renin, not by salt, would likely be more successfully treated by an ACE inhibitor or a similar drug.

Getting Patients on the Right Drug

The guidelines "do not recognize that patients differ," he says. "That's the crux of the matter." Getting patients on the right drug, he says, could reduce the need to put them on multiple medicines.

Dr. Roccella says that while the dissent is fodder for further study, the evidence supports the new guidelines.

Write to Ron Winslow at ron.winslow@wsj.com¹