Metabolic Problems Linked to Cognitive Deficits in Teens

Reported by Dr. Tiffany Chao, ABC News Medical Unit:

Growing waistlines may be associated with shrinking brains in teens, a new study found .

The study of 110 American teenagers found those with metabolic syndrome - a combination of obesity, pre-diabetes, high blood pressure, high triglycerides and low levels of good HDL cholesterol - scored lower on math and spelling tests and shorter attention spans than their metabolically healthier classmates. They also had smaller hippocampi - brain areas involved in learning and memory - according to brain imaging.

"Lower cognitive performance and reductions in brain structural integrity among adolescents with metabolic syndrome [suggests] that even relatively short-term impairment in metabolism, in the absence of vascular disease, may give rise to brain complications," the study authors wrote.

The results, published today in the journal Pediatrics, could have worrisome implications for American children and adolescents, one in 12 of whom has metabolic syndrome.

"There are huge numbers of people out there who have problems with their weight," study co-author Dr. Antonio Convit, professor of psychiatry and medicine at NYU School of Medicine, said in a statement. "As yet, there has been very little information available about what happens to the brain in the setting of obesity and metabolic syndrome in children."

Previous studies have linked metabolic syndrome to brain impairments in adults. But it's unclear whether those deficits are related to the syndrome itself or to cardiovascular disease-related changes in blood flow.

This study, however, provides evidence that metabolic syndrome alone may worsen brain function, since adolescents do not have the same vascular problems that obese adults develop over time.

The study authors hope the results will motivate families to change their lifestyles for the better.

"Although obesity may not be enough to stir clinicians or even parents into action, these results among youth with metabolic syndrome strongly argue for an early and comprehensive intervention," they wrote.