Diagnosis of nonalcoholic fatty liver disease

Abstract

The diagnosis of nonalcoholic fatty liver disease (NAFLD) relies on confirmation of the presence of hepatic steatosis in more than 5% of hepatocytes by either imaging or histology without demonstrable secondary cause such as alcohol consumption, medications, hereditary or autoimmune disorders. NAFLD begins with simple steatosis that may later progress to steatohepatitis and end-stage liver cirrhosis. The differentiation of simple steatosis from steatohepatitis carries a prognostic value. Patients with steatohepatitis are at high risk of both liver and cardio-vascular related morbidity and mortality. NAFLD should be clinically suspected in individuals diagnosed with metabolic syndrome and metabolic risk factors. Liver enzymes are not reliable in diagnosing either hepatic steatosis or steatohepatitis, but the presence of abnormal liver functions should alert the clinician to arrange NAFLD workout. Advanced imaging techniques and various scoring systems are helpful to detect the extent of the disease non-invasively. Although, liver histology is considered the gold standard investigation in diagnosing and staging the disease, the liver biopsy is invasive and technically demanding.