Fatty liver disease may signal high CV risk.

Overweight or obese children who have nonalcoholic fatty liver disease appear to be at high risk of developing cardiovascular disease, according to new research data.

This subset of overweight children also appears to have a high incidence of metabolic syndrome and to be at risk for developing type 2 diabetes and end-stage liver disease, reported Dr. Jeffrey B. Schwimmer of the University of California, San Diego, and his associates.

The investigators examined the link between nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome because data on this association in the pediatric population are sparse. NAFLD, characterized by the accumulation of large droplets of triglycerides within hepatocytes, is the most common liver disease in children.

The study Findings showed that cardio vascular health must be addressed in any overweight child found to have NAFLD.

Such children and their parents should be counseled about nutrition, physical activity, and avoidance of smoking. Those who are unable to improve sufficiently with lifestyle modification "will likely receive pharmacotherapy for ... hypertension or dyslipidemia," even though the data on such medications in this population are insufficient, and it is unclear whether such treatments "'have a beneficial, neutral, or deleterious effect on the natural history of NAFLD," Dr. Schwimmer and his associates said.

The researchers studied 300 overweight or obese boys and girls aged 5-17 years (mean age 13 years). Half of these subjects had biopsy-proven NAFLD and the other half, who served as controls, did not. The two groups were well matched for age and severity of obesity. The researchers used overweight or obese children as controls because the "vast majority" of children with NAFLD are overweight or obese, they noted.

Metabolic syndrome was defined as a clustering of at least three of five risk factors for cardiovascular disease and type 2 diabetes: abdominal obesity, high triglycerides, low HDL cholesterol, elevated blood pressure, and impaired fasting glucose. The incidence of all these measures was significantly greater in the children with NAFLD than in the control children. The incidence of metabolic syndrome was significantly higher in the children with NAFLD (50%) than in the controls (15%).

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Moreover, after the data were adjusted to account for age, sex, race, body mass index, and hyperinsulinemia, children with metabolic syndrome had five times the odds of having NAFLD than did those without metabolic syndrome, the investigators said (Circulation 2008 doi: 10.1161/circulationAHA.107.739920).

This "demonstrates that obese children and adolescents with a definitive diagnosis of NAFLD have a more severe cardiovascular risk profile than [do] age-, sex-, and BMI-matched peers," Dr. Schwimmer and his associates said. The findings also suggest that fat accumulation in the liver "may play a more important role than obesity itself in determining the risk for 'weight-related' metabolic comorbidities."

BY MOON, MARY ANN

Contributing Writer Prevalence of Metabolic Syndrome in Overweight Or Obese Children Nonalcoholic fatty liver disease (n = 150) 50% Normal liver (n = 150) 15% Note: Children had a mean age of 13 years. Source: Circulation Note: Table made from bar graph.