Obese kids -- even as early as age 6 -- can start showing changes to their heart muscles that could lead to problems later, a new review of previously published studies shows. And some obese kids had elevated blood pressure, cholesterol and blood sugar at age 5.
This international study, published in the journal BMJ, combined the results of 63 studies on nearly 50,000 school-aged kids from 23 countries, making it one of the largest reviews of its kind to date. The researchers compared the data linking obesity in kids and risk factors for heart disease and stroke.
What they found was alarming. It gives obese kids a head start on developing heart disease, stroke and diabetes, said the lead study author, Claire Friedemann, a doctoral student in the Department of Primary Care Health Sciences at the University of Oxford in the United Kingdom.
The authors estimated that if obese kids continued to have high blood pressure as adults, their risk for heart attack and stroke would be 30 to 40 percent higher than that of their normal-weight peers.
Worldwide, emergency rooms are already starting to see patients with heart attacks and strokes at younger ages, said Dr. Richard J. Deckelbaum, professor of nutrition, pediatrics, and epidemiology at Columbia University Medical Center in New York City, who was not involved in the study.
"It's really not just something that will go away," he said. "People need to be aware that overweight kids are really going into adulthood with increased risks."
The review showed that obese kids had thicker heart muscles compared to normal-weight kids, even after adjusting for height. That was startling to some experts. Thicker heart muscles usually are linked to long-standing high blood pressure, said Dr. Robert M. Campbell, a pediatric cardiologist and chief of Cardiac Services at Children's Sibley Heart Center in Atlanta, Ga., who was not involved in the study. If severe high blood pressure goes untreated for too long in adults, he said, you can end up with thicker heart muscle that doesn't work properly.
Whether the thicker heart muscle found in these kids would eventually threaten their health, or if it is simply a marker for high blood pressure, remains unclear. However, the fact that this thickened heart muscle is being found in these young patients in the first place is clearly a problem, Campbell said.
The study authors cautioned that just because someone has these risk factors as a kid, that is no guarantee that he or she will develop diseases like heart disease, stroke, and diabetes as an adult. Still, these combined results based on many studies should not be ignored, Campbell said.
"I think there's a call for us to pay attention," he said. "Let's accelerate the conversation and get serious about this."
Fortunately, despite these sobering findings, Friedemann emphasized that all of the disease risk factors in this review can be prevented and reversed. She recommended targeting education efforts at an early age to teach children to assume responsibility for their own health to remain disease-free in the future.
"When you start healthy habits as a child," she said, "those habits are much easier to carry through to adulthood."