Volume 2 • Issue 3 • 1000127 J Liver ISSN: 2167-0889 JLR, an open access journal Open Access Research Article Notarnicola et al., J Liver 2013, 2:3 DOI: 10.4172/2167-0889.1000127 Increased Serum Levels of Oxidative Stress Markers in Patients with Liver Steatosis Maria Notarnicola 1 , Valeria Tutino 1 , Alberto R Osella 2 , Caterina Bonfglio 2 , Vito Guerra 2 and Maria Gabriella Caruso 1 * 1 Laboratory of Nutritional Biochemistry, Castellana Grotte (BA), Italy 2 Laboratory of Epidemiology and Biostatistic, National Institute for Digestive Diseases “Saverio de Bellis”, Castellana Grotte (BA), Italy *Corresponding author: Maria Gabriella Caruso, MD, Laboratory of Nutritional Biochemistry, National Institute for Digestive Diseases “Saverio de Bellis”, Via Turi 27, 70013 Castellana Grotte (BA), Italy, Tel: +39 0804994669; Fax: +39 0804994313; E-mail: gabriella.caruso@irccsdebellis.it Received August 26, 2013; Accepted September 05, 2013; Published September 13, 2013 Citation: Notarnicola M, Tutino V, Osella AR, Bonfglio C, Guerra V, et al. (2013) Increased Serum Levels of Oxidative Stress Markers in Patients with Liver Steatosis. J Liver 2: 127. doi:10.4172/2167-0889.1000127 Copyright: © 2013 Notarnicola M, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Background: Several studies have suggested that oxidative stress could play a role in the pathogenesis of nonalcoholic fatty liver disease and more precisely in the transition between simple fatty liver and steatohepatitis. Aim: This study aims to investigate if circulating levels of oxidative stress markers could be clinically associated with liver steatosis. Materials and methods: We present data obtained from a subsample of 70 subjects with liver steatosis enrolled by a nutritional trial, called NUTRIEPA study. Serum levels of oxidative stress markers were evaluated by ELISA assay. The diagnosis and the degree of liver steatosis were based on laboratory and ecographic measurements. Statistical methods included Kruskal-Wallis analysis of variance and, Wilcoxon signed-rank or Mann-Whitney test, where appropriate. The χ2 test has been performed to analyze categorical variables. Results: The subjects with severe or moderate steatosis had signifcantly higher serum levels of oxidative stress markers compared to subjects without steatosis. Conclusions: Increased serum levels of oxidative stress markers could be considered a marker of moderate and severe liver steatosis. Keywords: Oxidative stress markers; Hepatic steatosis Introduction Liver steatosis is characterized by an excess accumulation of triglycerides within hepatocytes. Excess hepatic fat accumulation could result from the following mechanisms: a) increased de novo fatty acid synthesis; b) decreased fatty acid oxidation; c) increased transport of fatty acids from the peripheral organs to the liver; d) blunted transport of fatty acids (triglycerides) from the liver to the general circulation and peripheral organs [1]. Steatosis is reversible and it has been considered as a benign condition for a long time; however, increasing evidence suggests that it is a potentially pathological condition. If the causal agent is not eliminated or injury persists, steatosis may progress to infammation, fbrosis and even cirrhosis of the liver, especially in the presence of hepatitis C virus, diabetes and obesity [2-4]. Considering its potential clinical relevance, researchers were prompted to discern the underlying mechanisms of steatosis. Liver steatosis is frequent in patients with metabolic syndrome and accumulating evidences suggest that lipid metabolism is as important to diabetes as carbohydrate metabolism [5]. Recently, high serum levels of Fatty Acid Synthase (FAS) have been detected in patients with chronic hepatitis viral infections and circulating FAS concentration correlated with the degree of liver steatosis [6,7]. Some studies have suggested that, apart from endotoxins, cytokines, hyperlipidemia and hyperinsulinemia, oxidative stress could play a role in the pathogenesis of Nonalcoholic Fatty Liver Disease (NAFLD) and more precisely in the transition between simple fatty liver and steatohepatitis (i.e. fatty liver coexistent with hepatocyte necrosis and infammation) [8]. Indeed, excessive fat accumulation in the liver, whatever its cause, is prone to attack by Reactive Oxygen Species (ROS), leading to lipid peroxidation with its cellular consequences. For example, increased lipid peroxidation has been documented in animal models, either drug-induced [9,10] or dietary [11,12] while in genetic models of steatosis, such as the ob/ob mice there is an increase in mitochondrial ROS production [13]. Few studies have documented the relationship between the extent of steatosis and systemic markers of oxidative stress. Two recent studies demonstrated diferent results in circulating levels of oxidative stress markers in NAFLD patients compared with age-matched controls [14,15]. Terefore in the present study we have determined whether blood oxidative stress parameters are related to the presence of liver steatosis and could serve as markers of liver fat accumulation at diferent grade. Methods Patients Tis work is part of NUTRIEPA study, a nutritional trial enrolling consecutive subjects with liver steatosis, diagnosed by abdominal ultrasound. In this report, we present data obtained from a subsample of 70 subjects. All subjects underwent a complete medical examination including weight and height measurements. Body Mass Index (BMI) was calculated as weight in kilograms divided by the square of the height in meters (kg/m 2 ). Participants were fasted for 12 h prior to examination. Blood samples taken from the subjects by venous J o u r n a l o f L i ve r ISSN: 2167-0889 Journal of Liver