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Kids' Early Weight Gain = Heart Risks

Risk Factors for Heart Disease Apparent at Age 7
WebMD Health News
Reviewed by Louise Chang, MD

Nov. 5, 2007 -- Know your kid's BMI!

That's the advice of doctors who found that changes in BMI, or body mass index, in 4-year-olds can signal impending heart disease.

BMI, a ratio of weight to height, is a measure of obesity. It naturally drops as plump, pudgy newborns shoot up in height. Then, at some point, usually between the ages of 4 and 7, it starts to go up again. Doctors call this the BMI rebound age.

The new study shows that the earlier a child's BMI reaches rock bottom, the more likely he or she will have risk factors for heart disease at the ripe age of 7.

The findings were presented at the American Heart Association's (AHA) Scientific Sessions 2007.

Early BMI Rebound Signals Obesity Later

Previous research has shown that the earlier the BMI rebound occurs, the greater the risk of obesity and obesity-related disease later in life.

"A lot of doctors aren't measuring BMI and that's a tragedy," says researcher Thomas R. Kimball, MD, a pediatric cardiologist at Cincinnati Children's Hospital Medical Center.

Parents should take it on themselves to make sure they really understand what BMI is, Kimball says. Then prod your child's pediatrician to measure it at every visit.

If a child's BMI is high, don't justify it as baby fat that will be outgrown, says AHA spokesman Vinay Nadkarni, MD, of Children's Hospital of Philadelphia.

"The earlier we intervene, the better the chance we have of modifying our kids' behaviors and improving long-term heart health," he tells WebMD.

"The answers to this epidemic are known -- diet, exercise, fewer video games and TV, and more time outside," Kimball says.

Early BMI Raises Cardiovascular Risk by Age 7

The new study followed 308 boys and girls from age 3 to age 7. All had their BMI measured every four months over the four-year period.

Based on when they reached their BMI rebound age, the kids were divided into three groups: 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 middle group, it was 5.4 years for boys and 5.0 years for girls.  In the oldest group, the rebound age was 6.6 years for boys and 5.7 years for girls.

By age 7, children in the early group had a host of heart disease risk factors. They had higher blood pressure and higher levels of the fat hormone leptin. Their blood insulin levels rose, indicating an increased risk of diabetes.

The findings come at a time when the prevalence of overweight children in the United States is increasing. In 2003-2004, an estimated 17% of children 2 to 19 years old and 18.8% of children 6 to 11 years old were overweight, according to the National Health and Nutrition Examination Survey (NHANES).

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