Current guidelines for the management of non-alcoholic fatty liver disease: A systematic review with comparative analysis

Abstract

The current epidemic of non-alcoholic fatty liver disease (NAFLD) is reshaping the field of hepatology all around the world. The widespread diffusion of metabolic risk factors such as obesity, type2-diabetes mellitus, and dyslipidemia has led to a worldwide diffusion of NAFLD. In parallel to the increased availability of effective anti-viral agents, NAFLD is rapidly becoming the most common cause of chronic liver disease in Western Countries, and a similar trend is expected in Eastern Countries in the next years. This epidemic and its consequences have prompted experts from all over the word in identifying effective strategies for the diagnosis, management, and treatment of NAFLD. Different scientific societies from Europe, America, and Asia-Pacific regions have proposed guidelines based on the most recent evidence about NAFLD. These guidelines are consistent with the key elements in the management of NAFLD, but still, show significant difference about some critical points. We reviewed the current literature in English language to identify the most recent scientific guidelines about NAFLD with the aim to find and critically analyse the main differences. We distinguished guidelines from 5 different scientific societies whose reputation is worldwide recognised and who are representative of the clinical practice in different geographical regions. Differences were noted in: the definition of NAFLD, the opportunity of NAFLD screening in high-risk patients, the non-invasive test proposed for the diagnosis of NAFLD and the identification of NAFLD patients with advanced fibrosis, in the follow-up protocols and, finally, in the treatment strategy (especially in the proposed pharmacological management). These difference have been discussed in the light of the possible evolution of the scenario of NAFLD in the next years.

Keywords: Clinical guidelines; Liver biopsy; Liver steatosis; Metformin; Non-alcoholic fatty liver disease; Non-invasive diagnosis; Pioglitazone.

Figure 1

Main difference between non-alcoholic fatty liver and non-alcoholic steatohepatitis. A: Non-alcoholic fatty liver; B: Non-alcoholic steatohepatitis. NAFL is characterized by minimal inflammatory infiltrate without hepatocyte ballooning (arrow). Instead, NASH is associated with lobular inflammatory infiltrate and hepatocyte degeneration (arrow). NAFL: Non-alcoholic fatty liver; NASH: Non-alcoholic steatohepatitis.

Figure 2

Aspects of liver steatosis according to the different imaging techniques. In normal ultrasound examination liver parenchyma is isoechoic to the renal parenchyma in normal conditions (A1), becoming hyperechoic in presence of liver steatosis (A2). In comparison to a normal liver (B1), a fatty liver appears hypodense compared to the spleen and to the hepatic veins (B2) in computed tomography scans. Finally, in the setting of a severe steatosis, the magnetic resonance signal has a clear fall from in phase (C1) to out phase sequencings (C2).