FRIDAY, Oct. 15 (HealthDay News) -- For overweight children, losing just a little weight can significantly lower their blood pressure, according to researchers from Indiana University School of Medicine.

High blood pressure, or hypertension, in children sets the stage for complications later in life, such as heart disease, stroke and diabetes, they noted.

"The effect of weight on blood pressure is very different in children in different weight categories," said lead researcher Wanzhu Tu, an associate professor of medicine.

"For obese and overweight children, even a small reduction in weight will produce a stronger benefit in blood pressure control," Tu added, while for normal-weight children, blood pressure is not so dramatically affected.

The results of the study were to be presented Friday at the American Heart Association's High Blood Pressure Research scientific sessions in Washington, D.C.

For the study, Tu's team collected blood pressure data on 1,113 children. The researchers compared the children's body mass index (BMI, a measure of body weight) to charts depicting normal blood pressure based on age, sex and height.

The study authors found that BMI had little effect on blood pressure among normal-weight children, but it had a significant effect on overweight children.

In fact, among overweight boys, BMI had an effect on their systolic blood pressure reading that was 4.6 times the effect found among normal-weight boys. The findings were similar among girls, Tu's group added.

Commenting on the study, Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, said that "obesity is a serious health concern for children and adolescents."

Obesity and overweight in childhood are well-documented to be associated with high blood pressure, abnormal cholesterol levels, reduced insulin sensitivity, and abnormal blood vessel function, Fonarow said.

"Aggressive steps are needed to prevent and treat obesity in childhood and adolescence to avoid subsequent cardiovascular health problems in adulthood," Fonarow said.

As part of the obesity epidemic in the United States, high blood pressure among children seems to be very common.

In another presentation at the meeting, researchers collected blood pressure readings on more than 62,000 fifth graders from West Virginia.

The investigators found that 19.7 percent had blood pressures that were higher than normal for their sex and height.

More information

For more information on high blood pressure, visit the American Heart Association.