OBJECTIVE: To review studies that investigated the prevalence of nonalcoholic fatty liver disease (NAFLD) in children. DATA SOURCE: Medline (PubMed) and Latin American and Caribbean Centre on Health Sciences Information (LILACS) were searched regarding the period from 1997 to 2008, using the combination of the following descriptors: "nonalcoholic fatty liver disease", "hepatic steatosis", "nonalcoholic steatohepatitis", "overweight children", "overweight adolescent", "pediatric obesity", "children obesity", "childhood obesity". DATA SYNTHESIS: 14 manuscripts were selected: five cross-sectional, one case-control, and eight cohort studies. Evaluation of quality between reviewers showed optimal agreement (k=0.81), with a 95% confidence interval of 0.52-1.00 (p<0.001), but only one study was considered excellent. All studies showed association between obesity and NAFLD, with a prevalence rate varying from 3.0 to 60.3%. The studies indicate that the biochemical and image alterations normalize with programs of weight loss that apply diets and physical exercises. There was a high prevalence of NAFLD among boys, increasing with age. Insulin resistance was often reported as associated with the progression of NAFLD. CONCLUSIONS: Carefully designed studies are needed to clarify the association between obesity and NAFLD during childhood. NAFLD, which is the main cause of infantile liver disorder, should be investigated in all obese children.
Nonalcoholic fatty liver disease; obesity; children
