Evaluation of blood oxidative stress-related parameters in alcoholic liver disease and non-alcoholic fatty liver disease

Oxidative stress is implicated in the pathogenesis of liver disease. We investigated oxidative stress-related parameters and correlated with clinical findings in 35 non-alcoholic fatty liver disease (NAFLD) patients, 38 alcoholic liver disease (ALD) patients and 38 normal subjects. NAFLD patients showed significantly higher body mass index, cholesterol, LDL-cholesterol, VLDL-cholesterol levels and transaminase activities compared to the other two groups. Haematological parameters were significantly altered in ALD patients and were reported only in male subjects. Glutathione content, catalase activity, glutathione reductase activity and glutathione peroxidase activity in NAFLD patients were reduced by 10.7%, 18.5%, 8.1% and 16.8%, respectively, and in ALD patients by 21.8%, 29.6%, 24.3% and 45.3%, respectively, compared to the normal group. However, thiobarbituric acid reactive substance content, superoxide dismutase activity and glutathione s-transferase activity were increased by 35.2%, 31.6% and 5.4%, respectively, in NAFLD patients, and in ALD patients by 75.2%, 72.7% and 32.4%, respectively, compared to the normal group. Oxidative stress is associated with collagen production and leads to fibrosis. Type IV collagen level in NAFLD patients (190.6 +/- 83 ng/mL) was significantly higher than in the normal group (124.5 +/- 14.5 ng/mL) and lower than in ALD patients (373.4 +/- 170 ng/mL). While type IV collagen level of > 124 ng/mL was a predictor of NAFLD patients from normal subjects, elevated ALT (> 40 IU/L) activity could discriminate either of the liver disease patients from normal subjects.