CHAPEL HILL, N.C. -- As few as eight weeks of health education classes, coupled with vigorous exercise, can reduce children's risk of developing heart disease during adulthood, a University of North Carolina at Chapel Hill study concludes.
The first-of-its-kind study, conducted by University of North Carolina at Chapel Hill School of Nursing investigators with National Institute of Nursing Research funding, involved 422 third- and fourth-graders from 18 randomly selected elementary schools across North Carolina. Unlike previous research, children studied had at least two risk factors for heart disease -- lower than average fitness levels and either high serum cholesterol or obesity.
A report on the findings appears in the August issue of Pediatrics, a medical journal.
"We began two programs in the schools designed to increase children's knowledge of nutrition, fitness, serum cholesterol levels, smoking, blood pressure and other topics as well as to increase their fitness," said Dr. Joanne S. Harrell, professor of nursing at UNC-CH and principal investigator. "Both teaching programs produced large reductions in cholesterol, 10.1 milligrams per deciliter in a classroom-based intervention and 11.7 milligrams per deciliter in a risk-based intervention. That's 4.6 percent and 5.6 percent, respectively."
Regular teachers taught the classroom group about health twice weekly, and children participated in vigorous activities such as jumping rope three times a week. Children in the more individualized risk-based group received either extra physical activity if their fitness was low or nutrition education if they were overweight or had high cholesterol. Researchers compared all groups before and afterward to determine the programs' effects.
A third group of comparison children who did not go through either eight-week program showed a slight drop on cholesterol, 2.3 milligrams per deciliter, she said. They received only their usual health and physical education classes.
"Systolic blood pressure increased less in both intervention groups than in the controls," Harrell said. "Both intervention groups showed a small reduction in body fat and higher health knowledge than the control group.
"There is growing recognition that atherosclerosis, the process by which arteries become clogged with fatty deposits, can begin in youth, with autopsy evidence confirming that fatty plaques can originate in the first two decades of life," she said. "Fatty streaks and atherosclerotic lesions have been found in the aorta and coronary arteries of children as young as age 6."
Nevertheless, Harrell said, whether such conditions should be treated early or even evaluated is controversial because of concerns about labeling children prematurely or subjecting them to lifelong treatment not proven to extend their lives.
"Although there is little resistance to lifestyle interventions aimed at reducing obesity, high cholesterol and high blood pressure, and at increasing physical activity, we do not know the best way to deliver such interventions to children with these risk factors," she said. "Our findings suggest a classroom-wide effort, rather than a more individualized approach, is the direction to take since it can be done more easily and reaches more children."
The study is part of the larger continuing Cardiovascular Health in Children study, a scientific effort based at UNC-CH's School of Nursing to learn about improving children's -- and later adults' -- heart and lung health.
Children in the newest study were a subset of 2,207 subjects involved in CHIC. They were evenly represented by sex, and 77 percent were white.
Other investigators were Drs. Stuart A. Gansky of the University of California an San Francisco; Robert G. McMurray, professor of physical education at UNC-CH, Shrikant Bangdiwala, research associate professor of biostatistics at UNC-CH; and Annette C. Frauman, associate professor of nursing at Emory University. Chyrise B. Bradley, research assistant professor of nursing at UNC-CH, served as project director.
Note: Project director Bradley can be reached at 919-966-3610 (w) or 304-2728 (h) since Harrell will not return from vacation until Monday, Aug. 3. Harrell's work number also is 919-966-3610, and she may be reachable at home Aug. 1-2 at 919-942-7978.
School of Nursing Contact: Renee Kinzie, 919-966-1412.
News Services Contact: David Williamson, 919-962-8596, or Bret Johnson, 962-0352.