Evaluation of systemic, metabolic, antioxidant markers and oxidation indicators in fatty liver disease associated with pediatric obesity

Objectives: Comparing the levels of C-reactive protein (CRP), interleukin 6 (IL-6), oxidized LDL (ox-LDL), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-?), the systemic indicators of oxidation and inflammation, alpha-tocopherol (?-tocopherol: vitamin E), retinol (vitamin A), ubiquinone (UQ), the antioxidant defence mechanisms, leptin, adiponektin, rezistin, the adipokines of obese children and children with nonalcoholic fatty liver disease (NAFLD) secondary to obesity with the healthy control group.Patients and Methods: A total of 47 obese children [n=20, NAFLD (+)obese, n=27, NAFLD (-) obese] and 30 healthy children with age interval 11-18 years, diagnosed as exogen obesity (BMI>%95) at the department of Pediatric Gastroenterology, Nutrition and Metabolism, Medical School of Dokuz Eylul University were enrolled to the study. The presence of fatty liver was identified by liver ultrasonography in obese children diagnosed according to antropometric data.Study cases were divided into three groups as NAFLD (+) obese, NAFLD (-) obese and healhty control. Routine biochemical analyses such as glucose, liver enzymes, lipid profile, CRP, insulin and hemogram were carried out. Patients with insulin resistance were determined by HOMA index results (over 2.7) obtained from insulin and fasting glucose values. The levels of plasma MDA and antioxidant vitamins were measured by HPLC systems with UV-dedector, other proinflamatory cytokins (TNF-?, IL-6), oxidation indicator (ox-LDL) and adipokines released from adipose tissue (adiponectin, leptin, resistin) by sandwich ELISA. Statistical analyses were performed by SPSS 15.0 programme.Results and Conclusion: There is no significant difference between average ages of study groups. BMI and the percentages of weight to height of antropometric data are significantly higher in both obese groups than the control group. Liver function tests (AST, ALT, GGT), insulin, HOMA index and TG levels of routine biochemical analyses are significantly higher in obese group [NAFLD (+) obese plus NAFLD (-) obese] than the control group. Total cholesterol, HDL and LDL levels of obese group are higher than the control group, however, this difference is not statistically significant. While TNF-?, CRP and leptin levels are significantly increased and adiponectin levels are significantly decreased in obese patients without fatty liver compared to the control group; in addition to these parameters IL-6 levels are also significantly increased in obese children with fatty liver. Significant increase in retinol levels compared to the control group is determined only in obese cases with fatty liver. In conclusion, the evaluation of the levels of retinol, antioxidant marker, and IL-6, inflammatory marker, is beneficial in discriminating obesity and obesity related hepatic steatosis in addition to liver ultrasonography.Key words: non-alcoholic fatty liver disease, obesity, adipokines, inflammation.