Recognizing and Diagnosing NAFLD in Children
NAFLD is an insidious disorder because the vast majority of affected children have no symptoms or signs despite significant hepatic and metabolic alterations. Clinical examination detects hepatomegaly in up to 50% of cases. The lower edge of the liver is palpable 1-2 cm below the right costal margin, usually in absence of other signs of chronic hepatopathies. The most common clues to the presence of NAFLD or NASH are the incidental finding of elevated liver enzyme levels on routine laboratory testing, or hepatomegaly identified on physical examination.
In other cases, NAFLD is accidentally discovered during abdominal ultrasound performed for other clinical reasons or as a diagnostic study for hypertransaminasemia or hepatomegaly. In combination with ultrasound evidence of liver steatosis, hypertransaminasemia is an indicator of NAFLD, but normal aminotransferase levels do not exclude liver steatosis or its progression to severe fibrosis and cirrhosis.
Most children with NAFLD/NASH are overweight (BMI ≥ 85th percentile) or obese (BMI ≥ 95th percentile), with prevalent abdominal distribution of adipose tissue (visceral fat). NAFLD/NASH is now considered to reflect a spectrum of the metabolic syndrome. Acanthosis nigricans and increased waist circumference are warning signs for NAFLD/NASH.
Children with fatty liver often also exhibit the stigmata of associated metabolic disorders, such as insulin resistance, hypertension, dyslipidemia, cardiac and respiratory alterations, and greater waist circumference.
Making the Diagnosis
The epidemic proportion of pediatric NAFLD and its demonstrated metabolic and hepatic long-term effects highlight the importance of an early and precise diagnosis. To date, NAFLD in children is a histologic diagnosis; liver biopsy is still the only tool able to distinguish between NAFLD and NASH, as well as to identify and quantify liver fibrosis and disease severity.
Recently, the Hepatology Committee of European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) published guidelines for the diagnosis of NAFLD/NASH in children. In the ESPGHAN guidelines, diagnostic work-up includes abdominal ultrasound and liver function tests, followed by exclusion of other causes of liver diseases. Liver biopsy is recommended in cases of clinically suspected advanced liver disease, to exclude other treatable diseases, before therapy, and when required by clinical research protocols. A family history of severe NAFLD; hepatosplenomegaly; and abnormal laboratory values, such as marked and persistent hypertransaminasemia, severe insulin resistance, and the presence of non–organ-specific antibodies, are taken into account in the decision to pursue liver biopsy.
Medscape Pediatrics © 2016 WebMD, LLC
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Cite this: An Obese Child With Fatty Liver and Abdominal Pain: The Gut/Liver Axis - Medscape - Jan 13, 2016.