en Nutrition Nutrition Original Research Original Research <p><strong>Background: </strong>Oxidative stress in obese people is an important pathogenic mechanism of an obesity-associated metabolic syndrome. We evaluated the association between circulating leptin levels with biomarkers of oxidative stress in overweight and obese participants.<br> <strong>&nbsp;&nbsp; Methods: </strong>This study was performed on 189 overweight and obese people aged 18-60 years old. Serum leptin, superoxide dismutase (SOD), high-sensitivity C-reactive protein (hs-CRP), homocysteine (Hcy), thiobarbituric acid reactive substances (TBARS) and amyloid A (SAA) concentrations were measured. Pearson correlation and multiple linear regressions were used to assess the relationships.<br> <strong>&nbsp;&nbsp; Results:</strong> We found that among the biomarkers of oxidative stress and inflammation in participants, serum hs-CRP and SAA were positively correlated with BMI (&beta;=0.003, P<0.001 and &beta;=7.83, P<0.001, respectively). This relationship remained significant even after controlling other oxidative stress and inflammatory indicators (&beta;=0.003, p<0.001 for hs-CRP), but this association disappeared for SAA. In addition, serum hs-CRP was positively correlated with leptin (&beta;=0.001, p=0.003). Regression analysis showed that there was no association between serum Hcy, SAA, TBARS and SOD with serum leptin concentrations<br> <strong>&nbsp;&nbsp; Conclusion:</strong> Overall, the current study demonstrated that serum hs-CRP and SAA levels were independently correlated with BMI. Furthermore, serum hs-CRP was positively correlated with leptin. Focusing on such strategies may lead to promises for alleviating obesity and its co-morbidities.<br> &nbsp;<br> &nbsp;</p> Leptin, Obesity, Oxidative stress, Inflammation 472 477 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-3252-1&slc_lang=en&sid=1 Nahid Aboutaleb aboutaleb.n@iums.ac.ir 200319475328460034127 200319475328460034127 No Physiology Research Center and Physiology Department, Faculty of Medicine Iran University of Medical Sciences, Tehran, Iran. Mitra Zarrati zarrati_ms@yahoo.com 200319475328460034128 200319475328460034128 No Faculty of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Elhameh Cheshmazar cheshmazar.elham@yahoo.com 200319475328460034129 200319475328460034129 No Faculty of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Raheleh Shokouhi Shoormasti raheleh.shokouhi@gmail.com 200319475328460034130 200319475328460034130 No Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Elham Razmpoosh 200319475328460034131 200319475328460034131 No . Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran & Department of Nutrition, Faculty of Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Farinaz Nasirinezhad nasirinezhad.f@iums.ac.ir 200319475328460034132 200319475328460034132 Yes Physiology Research Center and Physiology Department, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.