Systemic levels of lipid peroxidation and its metabolic and dietary correlates in patients with nonalcoholic steatohepatitis

BACKGROUND Products of systemic lipid peroxidation are important in the pathogenesis of cardiovascular disease. AND AIM: Subjects with NASH have increased hepatic lipid peroxidation, but it is unknown if they have increased oxidative stress and lipid peroxidation systemically. Therefore, we conducted a study to measure the circulating levels of lipid peroxidation products and their metabolic and nutritional correlates in patients with NASH and controls. METHODS: Systemic lipid peroxidation was assessed by measuring the levels of oxidized LDL (ox-LDL) and thiobarbituric acid-reacting substances (TBARS) in 21 subjects with NASH and 19 controls. Correlations were made between serum lipid peroxidation and nutritional determinants of oxidative stress and defense, serum lipids, insulin resistance, transaminases, and liver histology. The short-term nutrient intake was analyzed by maintaining a 3-wk dietary diary. RESULTS: The serum levels of ox-LDL were significantly higher in NASH patients compared to controls (56 +/- 16 U/L vs 40 +/- 12 U/L, respectively, p < 0.001). Similarly, serum TBARS were significantly higher in NASH patients compared to controls (3.4 +/- 1.3 vs 1.8 +/- 0.9 nmols/ml, respectively, p = 0.0001). Insulin resistance was independently associated with ox-LDL (p = 0.01) and TBARS levels (p = 0.01). We found no differences in the intake of various macro- and micronutrients between the two groups and there was no association between nutrient intake and ox-LDL or TBARS. CONCLUSION: Subjects with NASH have significantly higher systemic levels of lipid peroxidation products and this could indicate an increased risk of cardiovascular disease. More studies are needed to evaluate this possibility.