Non-Alcoholic Fatty Liver Disease: Diagnosis and Evaluation of Disease Severity

Abstract

Context: Considering the increasing prevalence of obesity and insulin resistance syndrome worldwide, non-alcoholic fatty liver disease (NAFLD) has become a major health concern. Early diagnosis and proper management might prevent disease progression. The aim of this article is to review the current knowledge on the diagnosis and evaluation of disease severity in NAFLD. Evidence Acquisition: After excluding causes of liver cell damage, the patients with persistent aminotransferase levels and well-defined criteria for fatty liver at ultrasonography are presumed to have NAFLD. When concomitant liver disease exists, the diagnosis of NAFLD is questionable without liver biopsy. Considering the limitations of diagnostic methods, selection of the best diagnostic approach has become a conflicting issue in NAFLD. Results: The review of literature showed that clinical findings, imaging studies, and laboratory investigations are commonly used for the diagnosis and the evaluation of disease severity in NAFLD. The results of non-invasive methods are sometimes inconclusive. The histological information is necessary for confirming the NAFLD diagnosis in this occasion. Meanwhile, invasiveness and possible complications make the liver biopsy an unacceptable method for most patients. It is not recommended routinely when the clinical and paraclinical findings are apparently in favor of NAFLD. Conclusions: In view of the limitations of the above-mentioned modalities, liver biopsy remains the gold standard method for documentation of diagnosis and estimation of disease severity in NAFLD.