The purpose of the study was to examine the effects of a seven-day creatine monohydrate (CrM) supplementation on oxidative DNA damage and lipid peroxidation after incremental exercise to exhaustion in wrestlers. Thirty-one college-aged male wrestlers (age 19.52±2.75 years, body mass 79.24±16.13 kg, height 173±6.49 cm, and body fat 16.37±5.92%) volunteered to participate in this double-blind, placebo controlled study and were randomly placed into either the placebo (PL; 4×5 g∙day-1 of maltodextrine powder; n=16) or the creatine monohydrate (CrM: 4×5 g∙day-1 CrM, n=15) group. Prior and following the supplementation period, participants performed an incremental cycling ergometer test to exhaustion. Urine samples were collected before and after the supplementation period at before (Pre), after (Post) and 24 hours after (24h Post) the exercise tests to determine the oxidative DNA damage and lipid peroxidation as measured by urinary excretion of 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-Isoprostane (8-iso PGF2α). Our finding demonstrates that the urinary 8-OHdG level significantly increased at 24h Post to exhaustion by 13.36% in CrM and 24.08% in PL before supplementation (p<.05). In contrast to DNA damage, we observed a non-significant trend toward a small increase in urine 8-iso PGF2α by 0.43% in CrM and 3.06% in PL group after exercise to exhaustion in athletes (p>.05). In addition, urinary 8-OHdG concentrations at 24h Post significantly decreased by 32.65% in CrM group after supplementation compared with before supplementation. After supplementation, urinary 8-OHdG concentrations were significantly lower in CrM group compared with PL at 24h Post (p<.05). These results suggest that CrM supplementation can attenuate oxidative DNA damage induced by acute exercise to exhaustion in wrestlers.
