Non-alcoholic fatty liver disease: The diagnosis and management

Abstract

Non-alcoholic fatty liver disease (NAFLD) is now the most frequent chronic liver disease that occurs across all age groups and is recognized to occur in 14%-30% of the general population, representing a serious and growing clinical problem due to the growing prevalence of obesity and overweight. Histologically, it resembles alcoholic liver injury but occurs in patients who deny significant alcohol consumption. NAFLD encompasses a spectrum of conditions, ranging from benign hepatocellular steatosis to inflammatory nonalcoholic steatohepatitis, fibrosis, and cirrhosis. The majority of hepatocellular lipids are stored as triglycerides, but other lipid metabolites, such as free fatty acids, cholesterol, and phospholipids, may also be present and play a role in disease progression. NAFLD is associated with obesity and insulin resistance and is considered the hepatic manifestation of the metabolic syndrome, a combination of medical conditions including type 2 diabetes mellitus, hypertension, hyperlipidemia, and visceral adiposity. Confirmation of the diagnosis of NAFLD can usually be achieved by imaging studies; however, staging the disease requires a liver biopsy. Current treatment relies on weight loss and exercise, although various insulin-sensitizing agents, antioxidants and medications appear promising. The aim of this review is to highlight the current information regarding epidemiology, diagnosis, and management of NAFLD as well as new information about pathogenesis, diagnosis and management of this disease.

Keywords: Liver disease; Non-alcoholic fatty liver disease; Non-alcoholic steatohepatitis.

Figure 1

Natural history of nonalcoholic fatty liver disease. Data adapted from Hsu et al[59]. NAFLD: Non-alcoholic fatty liver disease; HCC: Hepatocellular carcinoma; NASH: Non-alcoholic steatohepatitis.

Figure 2

Axial unenhanced computed tomography scan reveals diffuse liver steatosis. Data adapted from Charatcharoenwitthaya et al[76].

Figure 3

Axial enhanced computed tomography scan reveals diffuse liver steatosis. Data adapted from Rofsky et al[75].

Figure 4

T1-weighted magnetic resonance imaging of fatty liver, demonstrating a bright liver. Data adapted from Mazhar et al[74].

Figure 5

Sagittal ultrasound image of the liver shows diffuse liver steatosis. Data adapted from Yokoo et al[79].

Figure 6

Histologic features of simple steatosis (fatty liver). Data adapted from Feldman et al[69].

Figure 7

Histologic features of nonalcoholic steatohepatitis. Data adapted from Cortez-Pinto et al[83].

Figure 8

Diagnostic approach to patients with suspected nonalcoholic fatty liver disease. Data adapted from Feldman et al[69]. CT: Computed tomography; MRI: Magnetic resonance imaging; US: Ultrasound.