Response of protein S100B to playing American football, lifting weights, and treadmill running.

OBJECTIVE: To determine if serum S100B increases similarly as a result of playing American football compared to exercise alone. METHODS: Serum S100B was measured in division III collegiate football players before and after every home game during a single football season. Serum S100B was also measured before and after subjects walked on a treadmill for 30 minutes at a leisurely pace, ran on a treadmill while wearing and not wearing a football helmet at 6 mph for 8 minutes, and performed low-, moderate-, or high-intensity resistance exercise. RESULTS: Serum S100B increased significantly (P < 0.05) when subjects played in a football game, ran on a treadmill, or performed moderate-intensity resistance exercise. Pre-game serum S100B did not accumulate throughout the football season in any of the players (P > 0.05). The increase in serum S100B during football games was moderately and significantly correlated with both the number of hits (R2  = 0.407) and the number of plays (R2  = 0.484) that each player experienced (P < 0.001). Post-game serum S100B was greater in football players who played more than 50 plays compared to those players who played <50 plays, subjects who exercised on a treadmill, or subjects performing resistance exercise (P < 0.05). CONCLUSION: It is unclear if the higher S100B concentration in football players playing at least 50 plays was caused by exercise or hits. Therefore, if serum S100B is to be used as a biomarker of impacts, and possible brain injury in sport, exercise time and intensity should be taken into account as confounding variables.

Biomarkers of brain injury following an American football game: A pilot study.

The goals of this study were to determine if the biomarkers of head injury, NSE and S100B, increased in serum following an American football game. Serum creatine kinase (CK) and cortisol levels were also measured to determine muscle damage and stress caused by the football game. NSE, S100B, CK, and cortisol were measured in the serum of 17 football players before and after a collegiate junior varsity football game. No head injuries were reported by the players, athletic training staff, or coaches yet both NSE (Pre-game: 7.0 µg•L-1 ± 2.2 versus Post-game: 13.1 µg•L-1 ± 7.0, P <0.001) and S100B (Pre-game: 0.013 µg•L-1 ± 0.012 versus Post-game: 0.069 µg•L-1 ± 0.036, P <0.001) increased significantly. Neither CK (Pre-game: 90.5 U•L-1 ± 41.9 versus Post-game: 120.2 U•L-1 ± 62.7, P = 0.116) nor cortisol (Pre-game: 369.2 nmoles•L-1 ± 159.8 versus Post-game: 353.0 nmoles•L-1 ± 170.5, P = 0.349) increased significantly following the football game. There was little correlation found between S100B and body mass (R2 = 0.029) or CK (R2 = 0.352) levels. Although serum NSE and S100B increase as a result of playing in an American football game, the values are similar to or lower than levels found following competition in other contact and non-contact sports. Furthermore, the lack of correlation between S100B and body mass or CK indicates that S100B increases independent of body mass or muscle injury.