Figure 1.

The disease spectrum of NAFLD and the factors that influence the progression of NAFLD. (A) The spectrum of NAFLD ranges from simple steatosis to NASH and cirrhosis. Simple steatosis is characterized by the ectopic accumulation of lipid droplets in the cytoplasm of hepatocytes without hepatocyte injury, inflammation, and fibrosis histologically. Steatosis is self-limited and can be reversed by lifestyle modifications. Steatosis can develop to NASH, which differs from simple steatosis in the presence of hepatocyte injury, inflammation, and fibrosis. Long-term NASH leads to cirrhosis. In NASH-related cirrhosis, normal liver structure is damaged and replaced by type 1 collagen, and pseudolobules are formed; (B) The factors that influence the progression of NAFLD include energy excess, obesity, insulin resistance, genetic factors, gender and ethnic difference, gut microbiota, hypoxia, oxidative stress and lipid peroxidation, inflammatory cytokines, liver iron overload, endogenous cannabinoids receptor 1, and epigenetic modifications. Energy excess includes diet and sedentary lifestyle.