Dietary and physical activity patterns in children with fatty liver

To examine lifestyle patterns (diet, physical activity, energy expenditure) and metabolic variables (insulin resistance, oxidative stress, inflammation) in children with fatty liver detected by sonography.

Body composition (fat-free mass, body mass index-z), waist circumference (WC), dietary intake and energy expenditure were determined in 38 patients (ages 5-19 years) with fatty liver in whom specific causative liver disorders had been excluded. Laboratory investigations included liver biochemistries, C-reactive protein, tumor necrosis factor-alpha, glutathione peroxidase, vitamin E, and erythrocyte-glutathione.

In all, 36 of 38 children were overweight/obese; 37 had WC indicative of abdominal obesity. They displayed fasting hyperinsulinemia (n=15), hypertriglyceridemia (n=14), and hypoadiponectinemia (5.5+/-1.9 s.d. microg/ml; n=23) and insulin resistance (homeostasis model of insulin resistance (HOMA-IR)>3; n=21). Alanine aminotransferase (ALT) was elevated in 28 (43-556 U/l; median=56). Some inflammatory markers were elevated, whereas antioxidants were decreased. Diet was characterized by high saturated-, low polyunsaturated-fat, high fructose and sucrose intakes. Fructose intake was independently associated with insulin resistance and decreased serum adiponectin, regardless of serum ALT (P<0.05). Low and subnormal intakes of omega-3 fatty acids (C20:5 (n-3) and C22:6 (n-3)) were associated with abnormal serum ALT (P=0.006) and elevated HOMA-IR (P=0.01). Findings were similar in children 11 years old. Physical activity was low in both age groups.

Children with fatty liver detected sonographically have metabolic features of non-alcoholic fatty liver disease. Their diets are high in fructose and low in polyunsaturated fatty acid. Their activity patterns are sedentary. These lifestyle features may contribute to liver damage and can be a focus for therapeutic intervention.