NEW YORK (Reuters Health) - Nonalcoholic fatty liver disease in over-weight or obese children appears to be a risk factor for the metabolic syndrome, which is independent of body mass index (BMI) and hyperinsulinemia, the results of a case-control study indicate.

Dr. Jeffrey B. Schwimmer at the University of California, San Diego, and his associates selected 150 boys and girls from a prospective clinical research database of children 5 to 17 years of age referred to a pediatric gastroenterologic clinic for obesity and/or suspected nonalcoholic fatty liver disease.

As reported in the July 8th issue of Circulation, published online on June 30th, the patients, who had biopsy-proven nonalcoholic fatty liver disease, were matched to 150 controls for age and severity of obesity. Nonalcoholic fatty liver disease was ruled out in controls by the absence of hepatomegaly and normal liver enzyme levels.

Half of the study subjects were male; mean age for all subjects was 12.7 years; and 96% were

classified as obese. Mean and median BMI z scores and waist circumference did not differ significantly between groups.

The results showed that children with nonalcoholic fatty liver disease were significantly more likely to have metabolic syndrome than control subjects (50% vs 15%, p < 0.001). These children also "had a significantly higher frequency of central obesity, dyslipidemia, hypercholesterolemia, elevated blood pressure, and impaired fasting glucose."

Conversely, patients who already had the metabolic syndrome were five times more likely to have nonalcoholic fatty liver disease, after adjustment for age, sex, race, ethnicity, BMI, and hyperinsulinemia, the report indicates.

Dr. Schwimmer and his associates conclude that "the identification of nonalcoholic fatty liver disease in a child should prompt global counseling to address nutrition, physical activity, and avoidance of smoking to prevent the development of cardiovascular disease and type 2 diabetes."

Circulation 2008;118.