As Americans get older and fatter, the number of adults with high blood pressure has climbed to almost one in three over the past decade, putting more people at risk of a stroke, heart attack or kidney failure, government researchers said Monday.
A little more than a decade ago, the number was closer to one in four. And two decades ago, it was falling. But then came the obesity surge in the late '80s.
"It's not surprising because we've seen that Americans are getting fatter, and we know that blood pressure goes up when people gain weight," said Dr. David Goff, an epidemiology expert at Wake Forest University School of Medicine in North Carolina, who was not involved in the analysis of Census Bureau and health statistics.
About 65 million American adults now have high blood pressure - 30 percent more than the 50 million who did in the previous decade, according to the report in Hypertension: Journal of the American Heart Association.
The report did not specifically examine reasons for the spike, but experts said the aging U.S. population and the growing proportion of overweight and obese Americans are probably major contributors.
"The big message to the American public on that is that we need to pay attention to our lifestyle and those that are overweight need to get slimmer," said Dr. Daniel Jones, dean of the School of Medicine for the University of Mississippi Medical Center and an expert on high blood pressure.
The risk of hypertension, or high blood pressure, is increased by old age, excess weight and lack of physical activity. High blood pressure is defined as 140 over 90 or higher. Blood pressure less than 120 over 80 is generally considered ideal. People in between these categories are called pre-hypertensive.
The study found that at least 65 million Americans either have blood pressure in the high range, take blood-pressure lowering medicines or have been told at least twice that they had high blood pressure.
High blood pressure adds to the workload of the heart and arteries. Over time it can mean the heart and arteries do not work as well as they should.
High blood pressure can be treated with medicine and lifestyle changes, including eating less fat and more fruits and vegetables, becoming more physically active and limiting salt intake.
The new figures are from Census data and a 1999-2000 National Health and Nutrition Examination Survey, which included 4,531 adults. It estimates that 31.3 percent of Americans have high blood pressure, up from 28.9 percent in the previous national health report from 1988-94.
Dr. Jeffrey Cutler, senior scientific adviser at the National Heart, Lung and Blood Institute, said that between 1980 and 1990 the prevalence of high blood pressure was decreasing, but that was before the obesity surge of the late 1980s.
Four out of 10 black Americans have high blood pressure, compared with about three out of 10 Mexican Americans and whites.
"It's clear we're not paying enough attention to the things that can prevent and manage high blood pressures," Jones said.
There are no symptoms of high blood pressure. "That's why they refer to it as the silent killer," said Dr. Larry E. Fields, lead author of the study and an adviser to the U.S. assistant secretary for health. So he said healthy adults should be checked at least every two years.
Only two out of three people who have high blood pressure know that they do, and only one in three has the condition under control.
On the Net:
American Heart Association: www.americanheart.org