"It was surprising to find that they had an average IQ score of 78, whereas their control siblings were 106," Driscoll said. "We feel this may be another complication of obesity that may not be reversible, so it's very important to watch what children eat even from a very young age. It's not just setting them up for problems later on, it could affect their learning potential now."
While performing head MRI scans of subjects, researchers also discovered white-matter lesions on the brains of many of the Prader-Willi and early-onset morbidly obese patients. White-matter lesions are typically found on the brains of adults who have developed Alzheimer's disease or in children with untreated phenylketonuria, the researchers wrote.
These lesions could be affecting food-seeking centers of the brain, causing the children to feel hungrier. But they are most likely a result of metabolic changes that damage the young, developing brain, Driscoll said.
More studies are needed to understand what is causing these cognitive impairments, said Merlin Butler, M.D., Ph.D., a professor of pediatrics at the University of Missouri and chief of genetics and molecular medicine at Children's Mercy Hospital and Clinics.
"This could be a really significant observation," Butler said. "It's an interesting concept. It's a whole new area of investigation."
The findings are preliminary and additional studies are planned, Driscoll said. Jennifer Miller, M.D., a UF assistant professor of pediatric endocrinology and the first author of the study, and other researchers from UF, All Children's Hospital in St. Petersburg, Fla., and Baylor College of Medicine also took part in the research.
Although there was no known genetic cause for early-onset morbid obesity in the subjects studied, Driscoll said there are likely genetic and hormonal factors at play that re
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Contact: April Frawley Birdwell
afrawley@vpha.health.ufl.edu
352-273-5817
University of Florida
31-Aug-2006