TUESDAY, Oct. 4, 2011 (HealthDay News) -- Overweight or obese children are nearly three times as likely to have high blood pressure as kids who are a normal weight, according to a new study from the American Heart Association.
The increased risk applies to children of all ages, researchers said. Their advice: Parents and doctors should help children lose excess weight now to prevent high blood pressure from affecting them as adults.
In conducting the study, researchers followed 1,111 healthy Indiana school children, whose average age was 10, for 4.5 years. They found that when the children became overweight (having a body mass index, or BMI, at or above the 85th percentile), the amount of fat under their skin and surrounding their major organs, known as adiposity, harmed their health.
The study, published Oct. 3 in the journal Hypertension, revealed when the kids reached the overweight or obese category, the adiposity effect on their blood pressure was more than four times that of normal-weight children.
"Higher blood pressure in childhood sets the stage for high blood pressure in adulthood," said study lead author Wanzhu Tu, a biostatistics professor at Indiana University School of Medicine, in a Heart Association news release. "Targeted interventions are needed for these children. Even small decreases in BMI could yield major health benefits."
The researchers found 14 percent of the blood pressure measurements from overweight or obese children were at prehypertensive or hypertensive levels, compared with 5 percent of normal weight children. They also noted that blood levels of a hormone found in fat tissue, called leptin, and heart rate had a similar pattern as blood pressure.
The study authors deduced this hormone could play a role in obesity-induced blood pressure elevation, which could result in over- or underestimating the adiposity effect in certain children. They said more research is needed to determine what triggers hypertension when there is an increase in BMI and whether other factors, such as leptin or insulin, may play a role.
"If [doctors] see a dramatic weight gain in a child who already is overweight, they need to intervene with behavioral measures, such as dietary changes and increased physical activity, to improve overall health and minimize cardiovascular risk," concluded Tu.
The American Academy of Child & Adolescent Psychiatry provides more information on childhood obesity.