Overweight Teens Face Heart Risks as Adults

April 6, 2011 -- Researchers have long known that overweight or obese kids are more likely to grow up to be heavy adults, and as overweight adults, to be more likely to develop significant health problems associated with excess body weight, including cardiovascular disease and diabetes.

Now a new study published in TheNew England Journal of Medicine has added a significant wrinkle to the problem of growing childhood girth.

The study, which followed more than 37,000 teenage boys into their 30s, shows that some of the risks associated with being an overweight teenager apparently don’t go away, even if a person loses weight later in life. 

“Cardiovascular disease really is a pediatric illness. It begins in childhood,” says Peter T. Katzmarzyk, PhD, professor and associate executive director for population science at the Pennington Biomedical Research Center in Baton Rouge, La.

“Even if you change your behavior, there’s still this carryover effect that being obese or overweight as an adolescent seems to really last into adult health,” says Katzmarzyk, who was not involved in the study.

What’s more, researchers found that the risks appear to rise at body mass indexes (BMIs) that are considered to be well within the normal range. Body mass index is a measurement that relates weight to height.

“The risk goes up significantly for diabetes with a BMI value of 22.3 and for cardiovascular disease above a BMI of 20.9 and above,” says study researcher Amir Tirosh, MD, PhD. Tirosh is a fellow in the department of medicine, division of endocrinology, diabetes, and hypertension at Brigham and Women’s Hospital in Boston.

A male who stands 5 feet 6 inches and weighs 130 pounds has a BMI of 21, for example.

Teens who had BMIs higher than 25, which is the threshold for overweight, had nearly three times the risk of developing diabetes and nearly eight times the risk of having heart disease as young adults, compared to the lightest group, which averaged 5 feet 6 inches in height and weighed about 114 pounds.

Diabetes Risks May Be Changed

In contrast with what happened with heart disease in the study, researchers found that diabetes risk could be more malleable. That is, if heavy teens lost weight as adults, their risk of getting type 2 diabetes was erased.

“This is the good news, actually, of the study,” Tirosh says. “For those who would not grow up to become overweight or obese, the risk is completely reversible.”

Though the study had some limitations, including the fact that it didn’t include girls, experts say the finding was significant.

“I think it’s a very interesting and important study,” says Stephen R. Daniels, MD, PhD, chairman of the department of pediatrics at the University of Colorado Denver School of Medicine. Daniels is also pediatrician-in-chief at Children’s Hospital, Denver.