Factors influencing plasma brain-derived neurotrophic factor (BDNF) in adolescent sport participants

Brain-derived neurotrophic factor (BDNF) is being explored as a biomarker for sport-related concussion (SRC). We aim to explore BDNF contextualized by demographic and sport-related factors in adolescent sport participants. This cross-sectional study nested in a multi-site Canadian cohort study recruits a sample of uninjured male ( n = 60, 15.79 ± 1.17 years) and female ( n = 60, 15.97 ± 1.36 years) adolescent sport participants. We investigate plasma BDNF concentrations considering sex (M/F), age (years), concussion history (yes/no), bodyweight (kgs), height (m), BMI, menstrual cycle phase (follicular/luteal), and classification of sport participation (non-contact/contact/collision). Plasma BDNF was significantly higher for males ( β = 0.176, 95% CI: 0.010, 0.342, p = 0.038). No association was found between plasma BDNF and concussion history ( β = – 0.149, 95% CI – 0.323, 0.025, p = 0.093). Age was positively associated with plasma BDNF in females ( β = 0.089, 95% CI 0.002, 0.176, p = 0.044). Contact sport participants had significantly lower BDNF compared to non-contact sports participants ( β = – 0.462, 95% CI – 0.830, – 0.093, p = 0.014). BDNF increased with height ( β = 0.011, 95% CI – 0.001, 0.021, p = 0.028), but not bodyweight ( β = 0.005, 95% CI – 0.001, 0.012, p = 0.119), BMI ( β = 0.006, 95% CI – 0.017, 0.029, p = 0.062), or menstrual cycle phase ( β = – 0.210, 95% CI – 0.470, 0.051, p = 0.114). Overall, BDNF in adolescent sport participants was higher for males, increased with height, increased with age in females only, and was lower in contact sports. Future studies should consider participant characteristics and sport participation type when evaluating plasma BDNF as a biomarker for sport-related concussion.