Background: Considering that pre-diabetes is one of disorders that increases developing of diabetes, this study was performed to investigate the effect of L-Arginine supplementation on antioxidant enzyme activity, total antioxidant capacity, and body composition in patients with pre-diabetes.

Materials and Methods: A double-blinded randomized clinical trial was performed on 46 pre-diabetic patients. Patients in intervention (n=23) and  placebo groups received  3g/day L-arginine and placebo (three 1gr L-arginine capsules), respectively for 8 weeks. Anthropometric, body composition, and dietary intake assessments, and also biochemical tests were done at baseline and end of study. Total Antioxidant Capacity (TAC), glutathione peroxidase enzyme and superoxide dismutase activity were measured. Paired t-test, independent t-test and ANOVA were used to analyze quantitative variables.

Results: Thirty eight patients (19 subjects in each group) completed the study. After adjusting confounding factors, no significant difference in body composition, anthropometric indices and dietary intake was observed at the end of study (p<0.05 in all factors), but a significant difference in TAC level was observed in the intervention group at the end of study (p<0.001).

Conclusion: Supplemenation with 3gr/day L-arginine for 8 weeks led to raised serum TAC level without changes in body composition in pre-diabetic patients.

Background: The aim of this study was to investigate the response of the most important angiogenic and angiostatic factors to a session activity before and after a period of L-Arginine supplementation in active men.

Materials and Methods: In this practical and semi experimental study, 22 active men were selected by convenience sampling method and they were randomly assigned into supplement (n=11) and placebo (n=11) groups. Baseline levels of VEGF and endostatin were measured, then subjects participated an exhaustive treadmill protocol in pre-test and post-test. Immediately and two hours after the protocol, 3 cc blood samples were prepared. The subjects used daily 0.1 g.kg^-1 respectively taking l-arginine and placebo for 14 days. The results were analyzed at the significant level (p<0.05).

Results: Immediately after exercise, the levels of VEGF and VEGF to endostatin ratio were significantly decreased in both groups compared to baseline (p≤0.05), and two hours later this change were lower than the baseline value (p≤0.05). The levels of endostatin immediately after exercise were significantly increased in both groups compared to baseline (p≤0.05) and two hours later this change were lower than the baseline value (p≤0.05). Before and after L-Arginine supplementation, the levels, of VEGF and VEGF to endostatin ratio immediately after exercise were not significant(p≥0.05). while this change in the supplementation group were significantly increased two hours after exercise (p≤0.05). There was no significant change in the levels of endostatin between two groups immediately after exercise (p≥0.05); however, these changes were significantly decreased two hours after exercise (p≤0.05).

Conclusion: It seems that short-term L-arginine supplementation probably stimulate angiogenesis factors in response to exercise in active men.