Factors associated with hepatic steatosis in obese children and adolescents.

OBJECTIVES: Obesity is associated with high prevalence of hepatic steatosis. We speculate that determinant factors of susceptibility to hepatic steatosis in obesity could differ between children and adolescents.

PATIENTS AND METHODS: Blood biochemical parameters, systemic oxidative stress markers, proinflammatory cytokines, and adipokine levels were determined in 157 obese children and adolescents. The subjects were divided into 2 groups: children and adolescents, identified as such in accordance with Tanner stage and the measured level of dehydroepiandrosterone sulphate. Steatosis was evaluated by ultrasonography in 127 subjects.

RESULTS: Steatosis prevalence was 44.8%. In the "children" group, those with hepatic steatosis presented higher levels of erythrocyte oxidised glutathione (GSSG) and resistin, lower levels of high-density lipoprotein (HDL) cholesterol, and lower enzymatic activities of erythrocyte glutathione reductase (GRd) and glutathione oxidase (GPx). In the "adolescents" group, those with hepatic steatosis presented higher values for body mass index z score (BMIz), insulin, peptide C, homeostatic model assessment index (HOMA-IR), alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides, GSSG, and leptin. These subjects also presented lower values for soluble leptin receptor, GRd, and GPx. In the "children" group, the only independent factor of steatosis was a decrease in GRd activity (odds ratio [OR] 0.165, 95% CI 0.03-0.84, P = 0.030). Moreover, in the "adolescent" group, the independent factors were higher for GSSG (OR 6.8, 95% CI 1.6-28.7, P = 0.010) and HOMA-IR (OR 1.9, 95% CI 1.17-3.1, P = 0.009).

CONCLUSIONS: Factors associated with hepatic steatosis differ between obese children and adolescents. Oxidative stress is seen to be the main process in children, whereas in adolescents oxidative stress and insulin resistance are significant factors for steatosis.