Direct hits to the head during amateur boxing induces a rise in serum biomarkers for brain injury

Abstract

Boxing exposes participants to the physiological response to high intensity exercise and also to direct body and brain trauma. Amateur boxing is increasing and females have also been included in the Olympics. The aim of this study is to assess the stress response and possible brain injury incurred during a match by measuring serum biomarkers associated with stress and cellular brain injury before and after combat. Sixteen male amateur boxers were studied retrospectively. The study population was divided into two groups: (a) a group that received predominantly punches to the head (PTH) and (b) a group that received predominantly punches to the body (PTB). Blood samples were taken before and five minutes after each contest. They were analysed for S-100B, neuron-specific enolase (NSE), creatine kinase (CK) and cortisol. The PTH group received direct contacts to the head (not blocked, parried or avoided) and to the body (n=8, age: 17.6 ± 5.3, years; height: 1.68 ± 0.13, meters; mass: 65.4 ± 20.3, kg). The PTB group received punches to the body including blocked and parried punches, but received no direct punches to the head, (n=8, mean ± SD, age: 19.1 ± 3.2 years; height: 1.70 ± 0.75, meters; mass: 68.5 ± 15 kg). Significant increases (P<0.05) were observed between pre- and post-combat serum concentrations in serum concentrations in PTH of S-100B (0.35 ± 0.61 vs. 0.54 ± 0.73, μg.L−1) NSE (19.7 ± 14 vs.31.1 ± 26.6, ng.ml−1) and cortisol (373 ± 202 vs. 756± 93, nmol.L−1). Significant increases (P<0.05) of creatine kinase were recorded in both groups. This study demonstrates significant elevations in neurochemical biomarkers in boxers who received direct blows to the head. However, further work is required to quantify this volumetric brain damage and long term clinical sequelae.