More Kids Developing High Blood Pressure

By Rob Stein
Washington Post Staff Writer
Tuesday, September 11, 2007

The rate of health-threatening high blood pressure has started rising among American children for the first time in decades, researchers reported yesterday, confirming a trend long feared by experts worried about the consequences of the obesity epidemic.

After dropping steadily since the 1960s, diagnoses of early hypertension and full-blown high blood pressure began creeping up among children and adolescents beginning in the late 1980s as the obesity epidemic apparently began to take its toll, according to an analysis of data collected from nearly 30,000 youths by seven federal surveys.

Although the increases so far have been small -- just 2.3 percentage points for early hypertension and 1 point for full-blown hypertension -- they translate into hundreds of thousands more children developing what often becomes a chronic, lifelong condition. Considered primarily an affliction of the middle-aged and elderly, high blood pressure is a leading cause of a host of health problems, including heart attack and stroke -- the nation's top killers.

"This is a major public health problem," said Rebecca Din-Dzietham of the Morehouse School of Medicine in Atlanta, who led the study, which will be published in the Sept. 25 issue of the American Heart Association journal Circulation. "Unless this upward trend in high blood pressure is reversed, we could be facing an explosion of new cardiovascular disease cases in young adults and adults."

With an adult form of diabetes already being diagnosed more frequently in children and more young people developing high cholesterol, the new finding is another indication that the obesity epidemic is spawning a generation at heightened risk for illnesses that struck their parents and grandparents only later in life, experts said.

"This is very worrisome," said Elizabeth G. Nabel, director of the National Heart, Lung and Blood Institute. "Typically in the past we didn't begin to see high blood pressure until someone was in their 30s or 40s. This is another piece of evidence suggesting that the obesity epidemic will likely turn into a heart disease epidemic."

Previous research had indicated that the obesity epidemic was driving up blood pressure levels among children. But the new research is the first to document that the higher levels had begun translating into medically significant high blood pressure and a recently defined condition known as early hypertension or pre-hypertension.

"Our paper is the first to describe an increase in the prevalence of high blood pressure," Din-Dzietham said. "I think we should . . . ring the alarm bell."

Din-Dzietham and her colleagues analyzed data collected in nationally representative surveys conducted between 1963 and 2002 by the federal government's National Center for Health Statistics, involving 29,165 girls and boys, ages 8 to 17.

The researchers found that the prevalence of childhood obesity drifted slightly but steadily higher between 1963 and 1980, when it started rising rapidly. It affected less than about 6 percent of U.S. children in 1963 but nearly 17 percent by 2002.

The proportion of children and adolescents with pre-hypertension rose from 7.7 percent to 10 percent between 1988 and 2002, while the rate of hypertension increased from 2.7 percent to 3.7 percent. That percentage-point increase translates into an additional 410,150 children nationwide, Din-Dzietham calculated.

Unlike for adults, there is no single reading that constitutes the threshold for high blood pressure and pre-hypertension for children. Normal blood pressure varies depending on age, sex and height.

Although other factors may be playing a role, such as children getting less exercise, eating more salty fast food and prepared foods, and experiencing greater stress, researchers believe obesity is the main culprit.

"If you were going to make a list of the factors that are driving this, obesity would be numbers one through 10," Nabel said.

In addition to putting children at risk of health problems later on, high blood pressure can have more immediate effects, requiring constant monitoring, experts said.

"It often forces them to limit their daily activities," said Melinda Sothern of the Louisiana State University Health Sciences Center in New Orleans. "It robs them of their childhood, really. They're robbed of the natural enjoyment of being a kid -- being able to play outside, run, participate in gymnastics. If they have high blood pressure, they have a constant risk of stroke."

Experts recommend that children with early hypertension or hypertension be put on a carefully controlled diet-and-exercise regimen to try to lower their blood pressure to safe levels. If that fails, drugs can be prescribed.

"If children are becoming hypertensive in their teens, they may be committing themselves to lifelong therapy for hypertension," Nabel said.

The findings underscore the need to screen children and adolescents for the condition, experts said.

"There are more and more kids out there who have high blood pressure, and pediatricians and family physicians have to make sure they are taking blood pressure in children and adolescents," said Stephen R. Daniels, a professor of pediatrics at the University of Colorado School of Medicine, speaking on behalf of the American Heart Association.

© 2007 The Washington Post Company