Tabriz University of Medical Sciences Advanced Pharmaceutical Bulletin 2228-5881 4 5 2014 12 30 Effects of L- Arginine Supplementation on Antioxidant Status and Body Composition in Obese Patients with Pre-diabetes: A Randomized Controlled Clinical Trial 449 454 10.5681/apb.2014.066 EN Siavash Fazelian Mostafa Hoseini Nazli Namazi Javad Heshmati Mehdi Sepidar Kish Maryam Mirfatahi Ahmad Saedi Some Olia Journal Article 10.5681/apb.2014.066 2013 12 21 Purpose: The aim of present study was to determine effects of L-Arginine supplementation on antioxidant status and body composition in obese patients with prediabetes. Methods: A double-blind randomized control trial was performed on 46 (24 men, 22 women) obese patients with prediabetes. They were divided randomly into two groups. Patients in intervention (n = 23) and control group (n=23) received 3 gr/day L-arginine and placebo, respectively for 8 weeks. Anthropometric indices, dietary intake and biochemical measurements ((serum total antioxidant capacity (TAC), Glutathione Peroxidase (GPx) and Superoxide Dismutase (SOD)) were performed at the baseline and after 8-week intervention. Results: The mean age and BMI of participants were 44.29±8.65 years old and 28.14±1.35 kg/m2, respectively. At the end of study, in both intervention and control group, percentage of carbohydrate decreased and %fat intake increased compared to the baseline (P<0.05). After adjusting for dietary intake, no significant difference was observed in Fat Mass (FM) and Fat Free Mass (FFM) between two groups (P>0.05). Among measured biochemical factors, only serum TAC level showed significant differences at the end of study in the intervention group compared to the control group (pv<0.01). Conclusion: 3gr/day L-Arginine supplementation increased TAC level in obese patients with prediabetes.