Hypertension risk greatly increased for children in top 15% of BMI

October 20, 2011

Children in the 85th percentile for body mass index (BMI) are at greatly elevated risk for high blood pressure and require regular monitoring as well as possible interventions, according to a new American Heart Association study. The study of 1,111 healthy Indiana school children found that the adiposity effect on blood pressure was minimal until patients reached the overweight category, when it increased 4-fold. Find out why researchers believe the hormone leptin may play a role in the relationship between weight and blood pressure.

Children in the 85th percentile for body mass index (BMI) are at greatly elevated risk for high blood pressure and require regular monitoring as well as possible interventions, according to a study from the American Heart Association.

The study of 1,111 healthy Indiana school children-42% black, equally divided by sex (mean enrollment age, 10.2 years)-found that the adiposity effect on blood pressure was minimal until patients reached the overweight category, when it increased 4-fold. Researchers observed a similar effect on children younger than 10 years, those aged 11 to 14 years, and those older than 15 years. The group underwent 9,102 semiannual blood pressure and height/weight assessments during that time period (mean follow-up, 4.5 years).

“Higher blood pressure in childhood sets the stage for high blood pressure in adulthood,” said Wanzhu Tu, PhD, lead researcher and professor of biostatistics at Indiana University School of Medicine in Indianapolis. “Targeted interventions are needed for these children. Even small decreases in BMI could yield major health benefits.”

Researchers emphasized the importance of viewing overweight and obese children differently from their normal-weight cohort, even if they seem healthy. “The adiposity effects on blood pressure in children are not as simple as we thought,” Tu said.

He especially cautioned parents and pediatricians to monitor weight gain in already heavy children.

“If they 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,” Tu said.

Researchers noted that leptin, the adipose tissue-derived hormone, together with heart rate, showed an almost identically patterned relationship to blood pressure as did BMI, suggesting a role of the hormone in the elevated blood pressure.

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