WEDNESDAY, June 2, 2004 (HealthDayNews) -- Metabolic syndrome, a constellation of conditions that together raise the risk of heart disease later in life, affects far more children than previously thought.
This increasing prevalence can be traced to the obesity epidemic, with almost 50 percent of severely obese children and adolescents in a new study fitting the criteria of metabolic syndrome.
"As the children become more obese, they tend to develop this cluster of complications, and that's not good because we know that having two or three or four of these risk factors puts them at very high risk for cardiovascular disease [in the future]," said study author Dr. Sonia Caprio, an associate professor of pediatric endocrinology at Yale School of Medicine. Her report appears in the June 3 issue of the New England Journal of Medicine.
"It's an eyeopener and a warning," added Dr. Gary Berkovitz, a professor of pediatrics and chief of pediatric endocrinology at the University of Miami-Jackson Hospital. "That it's 50 percent is very surprising. That's an awfully big number."
According to the article, adults with severe obesity have twice the risk of dying that adults who are moderately obese do.
Metabolic syndrome -- also known as syndrome X -- is generally defined as having one or more of these conditions: insulin resistance, abdominal obesity based on waist circumference (or, in children, a high body-mass index), high blood pressure, low "good" cholesterol and high triglycerides.
The underlying causes for metabolic syndrome are being overweight or obese, being physically inactive, and having a genetic predisposition.
"What was once called an adult disease actually has its roots in the pediatric age group," said Dr. Brenda Kohn, an associate professor of pediatrics at New York University School of Medicine in New York City. "We're seeing increasing blood pressure, increasing insulin resistance, and an increase in type 2 diabetes. There is actual disease present and, in addition to that, we see the markers of continuing disease developing that, if left unchecked and if the obesity is left unchecked, these markers will continue into adult life and will predispose individuals to atherosclerosis and other diseases."
The American Heart Association estimates that 20 percent to 25 percent of American adults have metabolic syndrome, but it's less clear how many children suffer from the condition. The government's third National Health and Nutrition Examination Survey, conducted between 1988 and 1994, found that 6.8 percent of overweight adolescents and 28.7 of obese adolescents were classified as having metabolic syndrome.
More young people are heavier today, however, meaning the prevalence could be much higher.
To get a more updated estimate, the authors of this study gave a glucose-tolerance test and measured height, weight, blood pressure, cholesterol and other indicators in 439 obese, 31 overweight, and 20 normal children and adolescents.
The prevalence of metabolic syndrome increased as kids got heavier. Overall, 38.7 percent of moderately obese subjects and 49.7 percent of severely obese participants had metabolic syndrome. None of the overweight or non-obese children and adolescents had the syndrome.
Metabolic syndrome was also associated with increased insulin resistance and with higher levels of C-reactive protein and of interleukin-6 (markers that may predict future cardiovascular disease). Levels of adiponectin, a molecule that prevents certain plaques, dropped.
"We are showing that as the child goes from non-overweight to obese to severe obesity, you see more and more of these problems," Caprio said. "There are other markers that the child is developing, such as inflammation markers, that have not yet been associated with children. If we're seeing low chronic subclinical inflammation already in a child, you can imagine if the child remains like that for years what this might be doing."
The practical message is not a new one. "The findings suggest that if obesity is reduced, the problems associated with metabolic syndrome can also be reduced," Berkovitz said.
"We see in our diabetic patients that even a 5-to-10 percent reduction in obesity dramatically improves their blood sugar control," added Gwen Enfield, a nutritionist and diabetes educator in the division of pediatric endocrinology at University of Miami-Jackson Hospital.
How to do that? The twin pillars of diet and exercise combined increasingly with medication, Berkovitz said. "Unless there is a major, major change in attitude in this country, diet and exercise will not be the answer for everybody," he stated.
That attitude change may prove to be the key. "There needs to be an understanding that being overweight, even to a moderate degree, is unhealthy," stated Enfield.
The American Heart Association has more on metabolic syndrome.