MONDAY, Nov. 5, 2007 (HealthDay News) -- Parents don't let your children grow up to be fat -- or even fat when they start grade school.
Children reach a low point in their body mass index (BMI, a ratio of weight to height) early in life, before the BMI rises in concert with childhood, adolescence and adulthood.
But the earlier a child reaches his or her low point and starts gaining weight (called BMI rebound), the greater the chances of developing cardiovascular risk factors as young as age 7, a new study found.
"Plump is not good. We're seeing adverse cardiovascular risk factors developing in early childhood," said Dr. Thomas R. Kimball, study senior author and a pediatric cardiologist at Cincinnati Children's Hospital Medical Center. "The obesity epidemic of kids today is going to be the heart disease epidemic 20 years from now."
Pediatricians need to scrupulously monitor their patients' BMI, even their very young patients, said the authors of the study, which was presented Monday at the American Heart Association annual meeting, in Orlando, Fla.
"This goes to show you that it's never too early to prevent heart disease," said Dr. Nieca Goldberg, medical director of the Women's Health Program at New York University Medical Center and a spokeswoman for the American Heart Association. "It's really important given all that we know about kids not exercising as much as they used to and eating high-fat, high-calorie fast food meals. We really need to stop it."
Previous research had shown that the earlier in childhood BMI rebound occurs, the greater the risk of obesity and obesity-related disease later in life. Overweight and obesity are growing problems for American children. U.S. figures estimate that 17 percent of children aged 2 to 19 years and 18.8 percent of children aged 6 to 11 are overweight.
For the new study, the researchers measured the BMI of 308 children (158 boys and 150 girls) every four months starting at the age of 3 and ending at age 7. The participants were mostly white and were recruited from the pediatric population of Cincinnati Children's Hospital, which led the study.
The children were divided into three groups depending on when they reached their BMI rebound age -- early, middle and late. The BMI rebound age for children in the early group was 4.4 years for boys and 4.2 years for girls. In the oldest group, the rebound age was 6.6 years for boys and 5.7 years for girls.
By the time they turned 7, children with an earlier BMI rebound age had higher blood pressure, higher blood insulin and leptin levels, and larger left ventricular and left atrial size. The ventricle and the atrium are chambers of the heart.
"Girls' rebound age was a little bit younger than boys, and that potentially can mean they are at an increased risk to be obese," Kimball said.
The study authors also found that children today, overall, had younger rebound ages than a generation ago.
Why is BMI rebound age so critical? "I don't know for sure, but it's probably because you just have a longer period of time that you're gaining weight," Kimball said. "The earlier you start, the more you're being exposed to being obese."
It's unclear if the problem is reversible, but teenagers who underwent gastric bypass surgery and lost large amounts of weight (60 to 70 pounds) saw their left ventricular size decrease, the researchers said.
"There needs to be education. I don't think even pediatricians or physicians are necessarily even measuring BMI," Kimball said. "We know what to do: Diet and exercise. It's the same old thing, and it's frustrating getting people to actually practice it."
Visit the Alliance for a Healthier Generation, a partnership between the American Heart Association and the William J. Clinton Foundation, for more on childhood obesity and wellness.