Resumen de Urinary N-Terminal Fragment of Titin Reflects Muscle Damage After a Soccer Match in Male Collegiate Soccer Players

Yoko Tanabe, Kazuhiro Shimizu, Emi Kondo, Mikinobu Yasumatsu, Daisuke Nakamura, Hiroyuki Sagayama, Hideyuki Takahashi

• Previous studies have demonstrated that noninvasive urinary N-terminal fragment of titin (U-titin) concentration highly correlates with serum creatine kinase (CK) activity, a classic invasive muscle damage marker. This finding indicates that U-titin could be used to estimate muscle damage. However, these results were achieved using a laboratory-based eccentric exercise model. Therefore, it remains unclear whether U-titin is useful for evaluating muscle damage occurring in field sports events. As a result, we evaluated whether U-titin concentration closely relates to serum CK activity after a soccer match. Seventeen collegiate soccer players (age: 20 +/- 1 year; height: 172 +/- 6 cm; body mass: 65 +/- 5 kg; Yo-Yo intermittent recovery test level 2, 1,135 +/- 196 m) completed a test match (2 halves of 45 minutes separated by 15 minutes of normal half-time). U-titin concentration, serum CK activity, countermovement jump performance, and muscle soreness were assessed 2 hours before the match and 30 minutes, 24 hours, and 48 hours after the match. U-titin concentrations and CK activity similarly increased at 24 hours and returned to the baseline value at 48 hours after the match. Moreover, the percentage of changes in U-titin concentration from baseline after the match significantly and positively correlated with serum CK activity (r = 0.82, p < 0.05). These results suggest that the noninvasive marker U-titin can be used to assess muscle damage conditions in field sports events, such as soccer matches.