The Effect of Eight Weeks Concurrent Training and Supplementation of L_Arginine on Plasma Level of 8-hydroxydeoxyguanosine (8-OHdG), Malondialdehyde and Total antioxidant capacity in Elderly Men (Multivariate Longitudinal Modeling)

Aging is a biological process that is associated with accumulation of oxidative damage to the DNA molecule. Considering that physical activities and nutritional supplements play an effective role in reducing the effects of aging, this study investigated the effects of eight weeks concurrent training and supplementation of L-arginine on stress oxidative biomarkers, including 8-hydroxydeoxyguanosine (8-OHdG), Malondialdehyde (MDA) and Total antioxidant capacity (TAC) in elderly men. Forty-four elderly men (mean age: 67.77±4.61 years), were selected and randomly divided into four groups (n=11 each): Concurrent Training+Supplement group (ES); Concurrent Training+Placebo group (EP); Supplement group and the Control group. The Concurrent Training+Supplement and Concurrent Training+Placebo groups performed the exercise protocol of eight weeks of concurrent training, three sessions per week. Every morning, one hour before exercise training, the concurrent Training+Supplement and the supplement groups consumed 1000 mg of L-Arginine. ELISA methods were used for measurement of biochemical variables and for analysis of data we used the multivariate longitudinal model. There were significant between-group differences in changes of 8-OHdG, MDA and TAC (P<0.001). OHdG and MDA in all three groups of ES (35.38% and 61.8%), EP (22.59%, 55.55%) and supplement group (14.94%, 95.3%) had a significant decrease (P<0.001). Also TAC increased significantly in the ES-(135.56%) EP-(76.21%) and the supplement group (21.27%) (P<0.001). Joint effect of training and supplementation was greater than their individual effects on 8-OhdG (β=-5.16, P<0.001), TAC (β=-2.30, P<0.001), and MDA (β=3.50, P<0.001). Also exercise per se had a significantly greater effect on responses than just supplementation. Findings of this study, it demonstrate that supplementation of L-arginine and combined aerobic and strength training can be used as to lower oxidative stress indices and improve antioxidant systems in the elderly.