Nonalcoholic Fatty Liver Disease (NAFLD): Approach in the Adolescent Patient

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver disease whose hallmark is the accumulation of large-droplet fat in hepatocytes. This metabolic disorder occurs mainly in overweight or obese individuals. The disease mechanism involves hyperinsulinemia and hepatic insulin resistance, not ethanol abuse. NAFLD may be the hepatic manifestation of the "metabolic syndrome" classically associated with type 2 diabetes mellitus and cardiovascular disease. NAFLD ranges from simple steatosis, which is the least rapidly progressing disorder, to nonalcoholic steatohepatitis to cirrhosis, which can evolve to chronic liver failure. The high prevalence of NAFLD in children has been recognized only in the past 5 to 10 years, as rates of childhood obesity have soared. Accordingly, the best strategies for diagnosis and treatment of childhood NAFLD are a work in progress and remain controversial. Weight reduction through a healthy diet and regular medium-intensity exercise is the mainstay of current treatment. Few research data are available to guide pharmacologic therapy. Certain points regarding management of childhood NAFLD require emphasis: It is a serious liver disease that requires detailed clinical investigation. Other liver diseases causing fatty liver and/or abnormal liver tests, notably Wilson disease and chronic viral hepatitis, need to be excluded. Liver biopsy can provide critical diagnostic and staging information. Associated genetic or endocrine disorders need to be identified. Treatment should begin with a low-glycemic index diet that provides adequate nutrients but is low in harmful fats and eliminates foods causing postprandial hyperglycemia. Initially, this can target two to three problem foods so that it is easy for the adolescent to follow. Regular exercise suited to the capabilities and interests of the teenager should be added to the daily routine. Where possible, a team approach, including a dietician and psychologist, should be utilized, as adolescents do better in a supportive atmosphere. Optimal drug treatment requires further research: current front-runners are vitamin E and metformin. The roles of drugs that alter appetite and bariatric surgery for adolescents with NAFLD have not been determined.