Nonalcoholic fatty liver disease (nafld)

[Vania]

Fatty liver is excessive accumulation of lipid in hepatocytes. Nonalcoholic fatty liver disease (NAFLD) includes simple fatty infiltration (a benign condition called fatty liver), whereas nonalcoholic steatohepatitis (NASH) is defined as the presence of fat leading to lipotoxicity and inflammatory damage to hepatocytes. Histologically, NASH is indistinguishable from alcoholic hepatitis. Thus to diagnosis NASH, underlying alcohol use must be ruled out. Differentiating simple steatosis from NASH can be difficult, and elevated liver enzymes are not a sensitive predictor for identifying NASH. The presence of metabolic syndrome (obesity, dyslipidemia, hypertension, and glucose intolerance) increases the likelihood that a patient has NASH rather than simple steatosis. Pathogenesis is poorly understood but seems to be linked to insulin resistance (eg, as in obesity or metabolic syndrome). Most patients are asymptomatic. Although noninvasive diagnostic tests are usually sufficient, liver biopsy remains the gold standard. Treatment includes elimination of causes and risk factors; new therapies are rapidly emerging but still in the clinical trial phase.
(See also the American Association for the Study of Liver Diseases 2018 practice guidance on the diagnosis and management of NAFLD.)
NAFLD includes simple fatty infiltration (a benign condition called fatty liver) and nonalcoholic steatohepatitis (NASH), a less common but more important variant. NASH (sometimes called steatonecrosis) is diagnosed most often in patients between 40 and 60 years but can occur in all age groups. Many affected patients have obesity, type 2 diabetes mellitus (or glucose intolerance), dyslipidemia, and/or metabolic syndrome.