By Amy Norton

NEW YORK, Feb 04 (Reuters Health) - Excess fat around the middle is linked to an increased risk of heart disease in adults, and now research suggests that it may also contribute to high blood pressure in boys.

New York researchers found that among the 920 healthy children and teens they studied, blood pressure rose in tandem with abdominal fat for boys of all ages and races. The relationship was not found among girls, they reported Monday in the advance online edition of Circulation: Journal of the American Heart Association.

Previous research has found body-fat distribution to be important in both boys' and girls' cardiovascular health. This study, according to the researchers, is the first to find a sex difference in the link between fat distribution and blood pressure in children and teens.

The reasons for the difference are unclear, according to the study's lead author, Dr. Dympna Gallagher of St. Luke's-Roosevelt Hospital.

But, Gallagher told Reuters Health, sex differences in cardiovascular health are nothing new. "In adults," the researcher noted, "abdominal fat is associated with greater cardiovascular risk in males than females."

With children, it is important to know what factors might elevate blood pressure because blood pressure is known to "track" from childhood to adulthood, according to Gallagher's team. High blood pressure is a major risk factor for heart disease, stroke and kidney disease.

In addition, teens diagnosed with high blood pressure have been found to have a high prevalence of left ventricular hypertrophy, an enlargement of the heart's main pumping chamber that raises the risk of heart attack and stroke.

None of the boys in the current study had high blood pressure, which is relatively uncommon in children. However, Gallagher said, boys with higher amounts of abdominal fat had blood pressure in the high range of "normal."

"We consider this to be important as we know that blood pressure tracks from childhood to adulthood, and childhood blood pressure is predictive of later (disease)," the researcher explained.

The findings, according to Gallagher, suggest that it is especially important to annually monitor blood pressure changes in children who are overweight or obese.

In the study, the researchers measured the children's body fat with tests of skinfold thickness and a special x-ray technique that gauges the density of tissue. They found that the amount of fat in the trunk was related to boys' blood pressure, independent of the amount of fat elsewhere in the body.

Among girls, black participants had a slightly higher average blood pressure than whites. The same was true of black boys compared with Asian boys.

　　From Reutershealth.com