Non-alcoholic fatty liver disease (NAFLD). Non-alcoholic steatohepatitis - NASH

Nonalcoholic fatty liver disease (NAFLD) includes a wide spectrum of liver damage: steatosis, steatohepatitis, and fibrosis and cirrhosis of the liver. The main risk factors are obesity, type-2 diabetes and hyperlipidaemia. NAFLD is found in 57-74% of obese adults and 22-53% of obese children. The pathogenesis is determined by the insulin resistance syndrome with lipolysis and hyperinsulinism, and oxidative stress resulting from free fatty acids via lipid peroxidation (two-hit hypothesis). Unspecific abdominal pain is reported; an enlarged liver is frequently detected on clinical examination. A third of the patients are found to have acanthosis nigricans. Transaminases are elevated (GOT<GPT), but there is no clear correlation with the liver histology. Computer sonography of the liver reveals an enhanced bright echo, while MRT allows quantification of the fatty degeneration. Differential diagnoses include hepatitis B/C, alpha-1 antitrypsin deficiency, CF,Wilson disease, autoimmune hepatitis, hypothyroidism, and coeliac disease. Weight loss (max. 500 g per week) and good metabolic control of diabetes are mandatory for the management of NAFLD. The long-term prognosis of NAFLD in children is unknown, but transaminases usually normalise after successful weight reduction. Fibrosis has an unfavourable prognosis.