With obesity on a steep rise among the young, signs of future heart disease… (Christopher Furlong / Getty…)
American adolescents already carry a heavy burden of future heart disease risk, and while obesity has contributed mightily to their poorer health prospects, normal-weight kids are by no means off the hook, a study produced by the Centers for Disease Control says.
In a study published Monday in the journal Pediatrics (read the full text here), CDC researchers say that overweight and obesity among American adolescents -- those between 12 and 19 years old -- has pushed the prevalence of pre-diabetes and Type-2 diabetes from 9% in 1999 to 23% in 2008.
Diabetes is a major risk factor for heart disease and stroke. Diabetic adults are two-to-four times likelier to have heart disease or a stroke than those without the metabolic condition, and about two-thirds of those with diabetes die of stroke or heart disease.
The proportion of teens with high blood pressure or borderline high blood pressure, and with high cholesterol levels or borderline high cholesterol did not change during that decade. But they were still remarkably high for such a young population: the study found that 22% of American adolescents have high LDL cholesterol or borderline high cholesterol, and that 14% of adolescents have high blood pressure or pre-hypertension. The study took another measure of heart disease risk -- low HDL, or "good cholesterol" levels. But researchers have recently called the usefulness of that measure into question.
Obese children were most likely to have one or more indicators of future heart disease risk (other than obesity itself): 61% had at least one heart disease risk factor, and 25% had two or more. Among overweight children, 49% were positive for at least one indicator of future heart disease and 18% had two or more; among normal-weight kids, 37% had at least one of the signposts of heart disease risk, and about 7% had two.
The study adds a further note of alarm to the rising public clamor to address the nation's crisis of obesity, which affects 36% of adults and 17% of kids. Public health authorities have warned that the generation of children among which obesity has soared will probably live less long than have their parents.
The study looked at comprehensive health data, collected and maintained in an ongoing federal study, of some 3,400 American adolescents between 1999 and 2008. Its findings suggest the obesity crisis among children will have long-term and far-reaching effects for their health and longevity prospects.
One widely cited study has found that 77% of obese children become obese adults, while only 7% of children who are not obese become obese as adults. But even among those who escape those statistical probabilities, damage to the heart is thought to start early among kids carrying too much fat.
In an interview, the study's lead author, CDC epidemiologist Ashleigh L. May, said the study also underscores the importance of pediatricians ferreting out heart disease risk early in kids who are obese, and in those who are not as well. "They should be ready to promote the appropriate behavioral and lifestyle interventions early," said May.
The National Heart, Lung and Blood Institute and the American Academy of Pediatrics have been refining their definitions of hypertension and abnormal blood lipid levels in children and teens, who are still growing. So the notion that heart disease risk could be identified early in life is relatively new -- as are approaches to treating them. The AAP ran into a storm of controversy when it recommended in 2008 that some children older than 8 years old with high cholesterol be aggressively treated with statin medications.