Difference and similarity between non-alcoholic steatohepatitis and alcoholic liver disease.

BACKGROUND

Non-alcoholic steatohepatitis (NASH) and alcoholic liver disease (ALD) are extremely similar in the pathologic findings and pathogenesis. This study aimed to elucidate the difference and similarity between these diseases.

METHODS

Twenty-six patients with NASH and 26 with ALD including 11 with alcoholic hepatitis underwent clinico-pathologic analysis. The visceral fat area and liver/spleen ratio, an index of the hepatic fat content, were evaluated with computed tomography. The hepatic iron deposit and oxidative stress induced-lipid peroxidation were estimated by Prussian blue staining and 3-nitrotyrosine staining, respectively.

RESULTS

The most prominent difference between NASH and ALD was the nutritional status, although elevation of AST/ALT ratio and gamma-GT is relatively characteristic of ALD. NASH was more frequently associated with diabetes mellitus as compared with ALD. The BMI and serum levels of total cholesterol and cholinesterase were higher in NASH than in ALD. Although the degree and distribution of fibrosis and necro-inflammatory reaction were similar in NASH and ALD, steatosis was more severe in NASH than in ALD. The liver/spleen ratio was lower and the visceral fat area was larger in NASH than in ALD, regardless of the coincidence of alcoholic hepatitis. Interestingly, the visceral fat area positively correlated with ALT and HOMA-IR in NASH, whereas these correlations were not observed in ALD. The hepatic iron deposit was less in NASH than in ALD, whereas lipid peroxidation in NASH was similar to that in ALD with alcoholic hepatitis and more advanced as compared with that in ALD without alcoholic hepatitis.

CONCLUSIONS

NASH was characterized with over-nutrition and visceral fat type obesity as compared with ALD. The visceral fat accumulation was associated with hepatic inflammation and insulin resistance in NASH, but not in ALD. The difference in the nutritional status between NASH and ALD is not only reflected in the clinical features but also may closely associate with the mechanisms of hepatocellular damage in these diseases.