Doctors Focus on Kids' Blood Pressure

Do you know your child's blood pressure?

Amid the world-wide obesity epidemic and broader concerns about improving heart health, blood pressure has emerged as an important question—for kids of any weight. Rising rates of hypertension among overweight kids is driving the concern, but genetics and rare medical problems also may be triggers. While high-blood pressure is generally considered an adult medical problem, its increasing prevalence among children and teenagers is putting many young people on an early trajectory for heart attacks, strokes and other serious problems.

"The foundation of cardiovascular disease develops during childhood," says Nathalie Farpour-Lambert, who heads the pediatric exercise medicine and obesity care program at University Hospitals of Geneva, in Switzerland. "There is evidence that from the age of 4 we can see the first signs of atherosclerosis," Dr. Farpour-Lambert says. "Forty years later, it results in coronary heart disease."

An estimated 5% of people age 18 and under have hypertension, up from about 1% three decades ago—largely reflecting the increased number of obese and overweight kids. The hypertension rate could actually be higher.

In West Virginia, a project over the past 12 years screened 60,000 fifth-graders for heart-risk factors and found 14% of youngsters considered at normal weight, and 21% considered overweight but not obese, had high blood pressure.

Just as with adults, a large portion of kids in potential trouble don't even know it. "It's an important health issue in youth and it's getting worse instead of better," says Reginald Washington, a pediatric cardiologist and chief medical officer at Rocky Mountain Hospital for Children, in Denver.

Researchers at Cincinnati Children's Hospital, in Ohio and elsewhere have linked pediatric high blood pressure with enlarged hearts and early stages of disease in the arteries, especially in kids who are overweight or obese. Enlargement of the heart, known by doctors as left ventricular hypertrophy, or LVH, is a thickening of the heart's main pumping chamber that results from the extra work the heart must do to pump against the resistance caused by high blood pressure.

"The heart is a muscle," says Tammy M. Brady, a pediatric nephrologist at Johns Hopkins Children's Center, in Baltimore. "If I'm lifting weights, my arm muscle is going to get bigger. When my heart is pumping against higher blood pressure, it's going to work harder and get bigger."

Children love it when their biceps get bigger. But it's not good to have a thick heart muscle unless it is acquired through athletic conditioning. The periodic exertion followed by rest and recovery that is part of working out can thicken an athlete's heart and make it more efficient, doctors say. In contrast, enlargement resulting from chronic, unremitting hypertension weakens the heart, causing it to stiffen. That compromises pumping function and ultimately will put an adult at risk of heart attack, heart failure and heartbeat irregularities that may cause sudden cardiac arrest.