Nonalcoholic fatty liver disease in overweight children and adolescents

OBJECTIVE: To investigate the prevalence and characteristics of non-alcoholic fatty liver disease (NAFLD) and identify predictors for NAFLD in an overweight paediatric population. METHODS: The study group included 58 overweight (BMI-SDS 3.37 +/- 1) patients aged 8-18 years attending the paediatric obesity clinic. They underwent a clinical and biochemical work-up and liver ultrasonography. Grading of liver steatosis severity was done according to discrepancy in ultrasonographic liver-kidney densities. RESULTS: The prevalence of NAFLD was 60.3%. There was a highly significant (p = 0.004) association between severity of obesity and the presence or absence of liver steatosis. The study cohort was divided into three groups: group 1 (patients with normal ultrasonographic liver structure and normal liver enzymes), group 2 (patients with ultrasonographic fatty liver and normal liver enzymes) and group 3 (patients with ultrasonographic fatty liver and elevated liver enzymes). The BMI-SDS was significantly higher in group 3 compared to group 1 (4.2 +/- 1.1 vs. 2.8 +/- 0.9, p < 0.001). The rate of obesity complications was more prevalent in group 3 compared to groups 1 and 2 (p < 0.001). The insulin resistance index was higher in group 3 compared to group 1 (0.75 +/- 0.2 vs. 0.47 +/- 0.3, p < 0.05). CONCLUSIONS: The prevalence of NAFLD in our study cohort was high (60.3%). Patients with steatosis and elevated liver enzymes had a higher risk for obesity complications. Measurements of liver enzymes alone are insufficient, and liver ultrasonography is required for early identification of NAFLD.