Nonalcoholic Fatty Liver Disease

Abstract

Worldwide, there is an epidemic of obesity and overweight, with two‐thirds of Americans affected. A strong association exists between excessive body weight and nonalcoholic fatty liver disease (NAFLD), the most common etiology of abnormal liver function tests. Nonalcoholic fatty liver disease is a spectrum of liver disease, from a “bland” fatty infiltration to chronic hepatitis (nonalcoholic steatohepatitis or NASH), that can result in cirrhosis and organ failure. With the increasing prevalence of obesity in the world, the proportion of people affected by NAFLD is only expected to be parallel. Although primarily noted in obese individuals, NAFLD has also been associated with a number of surgical procedures, metabolic conditions, and medications. NASH is commonly underdiagnosed as most affected patients are symptom free, and routine screening is not performed. Noninvasive diagnostic testing is not sensitive in diagnosis or staging the severity of disease. Fatty infiltration and oxidative injury to the hepatocytes are believed to be the major factors behind the progression of disease from simple fatty infiltration of the liver to chronic hepatitis. Understanding the inflammatory pathways involved in NASH is a subject of extensive research. Currently, few proven treatment options exist, and controlled weight reduction is the only safe modality recommended for treatment of NASH.

Ethnic and Sex Differences in Fatty Liver on Cardiac Computed Tomography: The Multi-Ethnic Study of Atherosclerosis

“…Insulin resistance leads to an increased availability of glucose and free fatty acids, thereby promoting intrahepatic triglyceride synthesis and liver fat accumulation (33). …”

Effect of resveratrol on experimental non-alcoholic steatohepatitis

“…Approximately 20-33% of adults in developed countries have NAFLD, while 2-10% have non-alcoholic steatohepatitis (NASH), the inflammatory form of the disease [1][2][3]. In NASH, steatosis is accompanied by intralobular inflammation with hepatocellular ballooning, which can lead to progressive fibrosis with an increased risk of cirrhosis and hepatocellular carcinoma [2].…”

Plasma cathepsin D correlates with histological classifications of fatty liver disease in adults and responds to intervention

“…NASH is characterized by hepatic lipid accumulation (steatosis) and inflammation. While steatosis itself is generally considered benign and reversible, the presence of inflammation will eventually set the stage for further liver damage, including fibrosis, cirrhosis and liver cancer12. Currently, elevations in plasma alanine transaminase (ALT), a liver enzyme, are the primary clinical abnormality detected in NASH patients.…”