That children are heavier on average today than children were a decade ago may now be common knowledge. The rise in weight appears to be accompanied by a significant increase in blood pressure among children between the ages of 8 and 17, say Tulane University epidemiologists in the May 5 issue of the Journal of the American Medical Association.
Lead author Paul Muntner and his colleagues analyzed data collected from 5,582 children and adolescents between the ages of 8 and 17 during the National Health and Nutrition Examination Survey. The data allowed a comparison of weight and blood pressure in children between 1998-1994 (3496 children) and 1999-2000 (2086 children). Between the two time periods, systolic blood pressure levels increased an average of 1.4 mm Hg and diastolic blood pressure levels increased 3.3 mm Hg. Both systolic and diastolic pressure measurements increased in African American, Mexican American and white boys and girls of all ages.
"The increase in blood pressure of same age children over a 10 to 15 year period is worrying because we know that blood pressure levels in childhood are predictive of adult blood pressure. These results suggest that in another 10 to 20 years we will be facing much higher rates of hypertension, heart disease and stroke, as these children become adults," says Muntner, as assistant professor of epidemiology at the Tulane University School of Public Health and Tropical Medicine. Muntner notes that this is the first study to examine blood pressure levels in Mexican-American children, which appear to be as high as African American childrenyýs levels and higher than the blood pressure levels of white children. The higher levels of blood pressure among Mexican American children than whites was determined to be largely due to a sharper increase in overweight in this group.
"We can attribute less than 30 percent of the increase to the rising number of overweight children during that time period," says Muntner. "We assume a lot of the increase in blood pressure levels is related to changes in the way children are eating and exercising."
During the 1988-1994 data collection, 12 percent of the children were overweight. By the 1999-2000 collection, 16 percent were overweight.
The analysis showed the following results between the two time periods: - Mean systolic blood pressure levels increased 1.4 mm Hg among boys and 1.5 mm hg among girls.
- Mean systolic blood pressure levels increased 1.9 mm Hg among non-Hispanic blacks, 2.3 mm Hg among Mexican Americans and 1.9 mm Hg among children 8 to 12 years old.
- Systolic blood pressure among non-Hispanic whites and those aged 13 through 17 years of age increased 1.0 mm Hg.
- Increases in diastolic blood pressure between the two time periods were large in all groups. Muntner and colleagues recommend further studies to determine the roles that diet and exercise plays in children's blood pressure. The coauthors on the study are Jiang He, Paul Whelton and Rachel Wildman, all of the department of epidemiology at Tulane; and Jeffrey Cutler from the National Heart, Lung and Blood Institute. The article is available on-line at: