May 19, 2006 -- Teens with prehypertension or high blood pressure are more likely to have high blood pressure and its related complications when they grow up unless they make some changes now, a new study shows.
The research was presented Friday at the 21st Annual Scientific Meeting of the American Society of Hypertension (ASH 2006) in New York City.
A blood pressure level of 140/90 mmHg or higher is considered high. If blood pressure is between 120/80 mmHg and 139/89 mmHg, it’s called prehypertension, according to the National Heart Lung and Blood Institute in Bethesda, Md.
Prehypertension means that you don't have high blood pressure now but are likely to develop it in the future. This condition also increases your risk of developing the known complications of high blood pressure -- namely heart disease and stroke.
In the new study of more than 8,000 adolescents aged 13 and 15, researchers compared single blood pressure readings taken two years apart. They found that there was a linear increase -- from normal blood pressure to prehypertension to hypertension -- in the percentage of adolescents classified with hypertension at the second examination. The data show that the progression of prehypertension to hypertension is approximately 7% per year.
Among the 4,147 boys in the study, weight was an important predictor of who would go on to develop high blood pressure. In fact, those boys who were initially heavier (as measured by body mass index) and continued to gain weight were at an increased risk of progressing to hypertension, compared with their thinner counterparts.
Among the 4,386 girls in the study, age was more significant. Specifically, girls aged 15 were more likely to have higher blood pressure than those who were 13 years old. The study used data from the National Childhood Blood Pressure Database.
“Knowing which youngsters are most likely to progress to hypertension would provide the ability to target preventive interventions,” researcher Bonita Falkner, MD, professor of medicine and pediatrics at Thomas Jefferson Medical College in Philadelphia, said in a written statement.
'Public Health Crisis'
Thomas D. Giles, MD, ASH president and a professor of medicine at Tulane University School of Medicine in New Orleans, is not surprised by the new findings. “We have begun to see an increasing number of preteens and teens who are developing multiple risk factors for cardiovascular disease,” he tells WebMD. “If preteens and teens don’t modify their lifestyle to reverse these risk factors, they will wind up with serious complications like stroke, heart attack, and early kidney disease and all the rest as young adults.”
While the new study suggests that increasing body weight is a predictive factor, Giles says that going forward, researchers will also look at waist size as a risk factor for developing high blood pressure.
“This is absolutely a public health crisis,” he says. “We just have to do something to get preteens and teens to be more active physically and have some semblance about what they are eating.”
Dana Greene, MS, RD, a nutritionist in private practice in Brookline, Mass., agrees with Giles. She routinely counsels adolescents with high blood pressure and other risk factors for heart disease. “Teens who know they have prehypertension or even high blood pressure can most likely avoid needing to take medication and developing complications of high blood pressure if they make some changes to their diet and lifestyle now,” she tells WebMD. Greene did not attend the ASH meeting.
“Regular physical activity is important and so is watching the amount of salt in the diet,” she says. A low-salt diet might help lower blood pressure. “The most important thing preteens can do is learn about which foods are salty and which are not because it is not always so obvious,” she points out. For example, it is obvious that potato chips are salty, but so are hot dogs. “We don’t often think of it that way because we don’t see salt on the outside of a hot dog.”
Many preteens and teens with prehypertension or full-fledged high blood pressure are also overweight or obese, she says. “Weight loss and limiting the saturated or animal fat in their diet can also help these children improve their heart disease risk factors, she says.