High Blood Pressure Cases Down ‘Unprecedented’ 14% : Health: U.S. officials cite increased attention to physical fitness, healthier diets, avoidance of smoking.

WASHINGTON —  The number of Americans suffering from high blood pressure dropped an “unprecedented” 14% between 1980 and 1991--a sign that certain lifestyle changes have begun to work, federal health officials reported Friday.

The National Heart, Lung and Blood Institute, part of the National Institutes of Health, said that the prevalence of high blood pressure, or hypertension, dipped from 58 million people in 1980 to 50 million in 1991.

Officials speculated that Americans’ increasing attention to physical fitness, healthier diets--especially lower sodium intake and reduced alcohol consumption--and smoking cessation could be responsible for the decline.

“People didn’t start doing these things yesterday,” said Dr. Claude Lenfant, director of the institute. “It’s been going on for years--and now we are seeing the results.”

An estimated 2 million Americans annually develop high blood pressure, the most critical risk factor for stroke. Hypertension is also a major contributor to heart disease--the nation’s No. 1 killer of both men and women--and to kidney failure.

The NIH called for a new national prevention campaign to target both the general population and individuals at high risk of developing hypertension, including blacks and those with a family history of high blood pressure, to lower the incidence even further.

That program would build on the continuing work of the National High Blood Pressure Education Program, a cooperative effort between the heart institute and several voluntary and professional health organizations that began in 1972.

“Despite the encouraging new statistics, there is still a lot of work to do,” Lenfant said.

“The complications caused by high blood pressure are insidious, progressive and costly,” he continued. “It is not enough to treat the condition. We need to help Americans avoid its development.”

Blood pressure is the amount of force exerted by the blood against the walls of the arteries. It is expressed in two numbers, usually one above the other, such as 120/80.

The first number--the systolic pressure--represents the force used when the heart beats. The second number--the diastolic pressure--is the pressure within the arteries between heartbeats. Anything above 140/90 is considered high.

Even so-called “mild” hypertension, which ranges between 140 and 159 for the systolic pressure and 90-99 for the diastolic, is considered dangerous, and should not convey a sense of “complacency,” officials said.

High blood pressure cannot be cured, but it can be controlled through proper treatment. Sometimes this can be done through weight loss, regular exercise and reducing alcohol, table salt and sodium, which is an ingredient in salt that is found in many packaged foods, baking soda and some antacids.

If these methods fail, it also can be controlled through the use of certain drugs. These include diuretics, or beta blockers, which are usually prescribed first, or calcium antagonists, angiotensin converting enzyme (ACE) inhibitors, alpha-receptor blockers and alpha-beta blockers, which are usually given if the other drugs do not work.

Dr. Michael J. Horan, the institute’s associate director for cardiology, said there were at least two types of evidence indicating that Americans had begun making lifestyle changes that could account for the decrease in cases of hypertension.

He cited statistics from the National Institute of Alcohol Abuse and Alcoholism of a 12% reduction of per capita consumption of alcohol between 1980 and 1989.

“Also, we have done some preliminary analysis of certain trials that look as if sodium consumption in the early 1980s was higher than in the latter ‘80s,” Horan said.

The NIH said it hoped to enlist health care providers to participate in the educational effort, as well as the food industry, “who would be encouraged to develop healthier products and better labels.”

The NIH said also that a survey conducted by the National Center for Health Statistics found a 65% increase between 1971 and 1991 in the number of hypertensives who were aware of their condition, and a 102% increase during that same period in the number who were on medication. The same survey found a 70% increase in the number of hypertensives who were on medication and had their high blood pressure under control.

These statistics, however, reflect an earlier measure at which blood pressure was defined as being high--160/95, the NIH said. Today, the level has been revised to 140/90.

The institute said there has also been a 60% increase in hypertension control rates for black men. Hypertension is the major health problem of adult blacks, the NIH said.

Preventing High Blood Pressure

The National Heart, Lung and Blood Institute recommends the following to prevent high blood pressure:

Control weight: The overweight have a twofold to sixfold higher risk of developing high blood pressure than those of regular body weight. About 20% to 30% of hypertension in the United States can be attributed to overweight alone.

Avoid excessive sodium chloride (table salt): Consume no more than 6 grams daily.

Exercise: Regularly perform some moderate intensity, low resistance, dynamic exercise, such as walking, cycling, dancing, swimming or gardening.

Avoid excessive alcohol use: Limit alcohol to no more than two drinks daily. About 5% to 7% of hypertension in the U.S. can be attributed to consumption of three or more alcoholic drinks a day.

WHAT THE NUMBERS MEAN

Classification of blood pressure for adults age 18 and older

Normal: Systolic less than 130, diastolic less than 85

High Normal: Systolic between 130-139, diastolic between 85-89

Hypertension:

Stage 1 (mild): Systolic between 140-159, diastolic between 90-99

Stage 2 (moderate): Systolic between 160-179, diastolic between 100-109

Stage 3 (severe): Systolic between 180-209, diastolic between 110-119

Stage 4 (very severe): Systolic 210 or greater, diastolic 120 or greater

Source: National Heart, Lung and Blood Institute