Chapter 7 Fatty liver and nonalcoholic steatohepatitis
NASH is thought to be a disease of lipotoxic injury to hepatocytes caused by nontriglyceride metabolites of free fatty acids. Triglyceride in the lipid droplets may actually be a protective response to store fatty acids in an inert form. The specific metabolites of free fatty acids that cause lipotoxic injury have not been fully identified. Possibilities include ceramides, diacylglycerols, lysophosphatidyl choline species, and phosphatidic acid species.
The liver disposes excess carbohydrates, especially fructose, by converting carbohydrate to fatty acids through de novo lipogenesis; excess carbohydrates from dietary sources (e.g., sugar-sweetened beverages) or provided parenterally (e.g., total parenteral nutrition) predispose to hepatic lipotoxicity.