NAFLD is one of the most common causes of elevated liver enzymes and
chronic liver disease in the Western world. Its incidence in adults and children
is rising rapidly owing to the ongoing epidemics of obesity (Chapter
227), type 2 diabetes mellitus (Chapter 237), and metabolic syndrome. Its
prevalence is quite high in certain patient populations; for example, nearly
80% of type 2 diabetic patients and 90% of morbidly obese individuals have
imaging evidence of NAFLD. Nearly one third of U.S. adults are estimated to
have NAFLD, and up to 5% of U.S. adults may have NASH. These percentages
compare reasonably well with other data suggesting that the prevalence
of cirrhosis from NAFLD is about 2%. Hispanics and whites are at higher risk
for NAFLD, whereas its prevalence is intriguingly quite low in African
Americans.