Table 1.

Differential diagnosis of NAFLD. Several conditions associated with liver steatosis are shown in this table, with possible pathogenetic mechanisms and associated references.

Conditions Associated with Liver Steatosis	Mechanism of Action	References
Alcohol (>20 g/day (women) or >30 g/day (men))	Redox state shift: fatty acid oxidation inhibition, induction of lipogenesis Altered VLDL secretion in the liver	[22]
HCV	Altered VLDL secretion in the liver Insulin resistance Mitochondrial dysfunction and oxidative stress	[23]
Medications (e.g., methotrexate, corticosteroids, valproate)	Fatty acid oxidation inhibition, induction of lipogenesis Mitochondrial dysfunction Impaired hepatic lipid secretion Insulin resistance	[24]
Lipid metabolism disorders: a/hypo-betalipoproteinaemia, Wolman’s disease	Impaired hepatic lipid secretion Impaired hydrolysis of cholesteryl esters and triglycerides	[25,26]
Metal storage disorders: Wilson’s disease	Copper-induced mitochondrial dysfunction	[27]
Autoimmune hepatitis	Drug-mediated effects	[28]
Coeliac disease	Weight gain on gluten-free diet Impaired hepatic lipid mobilization Intestinal malabsorption	[29]
Endocrine disorders: hypothyroidism, hypopituitarism, polycystic ovary syndrome	Reduced hepatic lipid utilization Insulin resistance Impaired insulin secretion	[30,31,32,33]
Starvation, parenteral nutrition	Impaired hepatic lipid secretion Reduced mitochondrial beta-oxidation	[34]
Lipodystrophy	Insulin resistance and ectopic fat accumulation	[35]