Cross-sectional associations of objectively measured physical activity with brain-derived neurotrophic factor in adolescents

- Association between objectively measured physical activity and serum BDNF was investigated in adolescents.
- Mean physical activity and MVPA were negatively associated with serum BDNF in boys.
- Mean physical activity and MVPA were not associated with serum BDNF in girls.

ObjectiveThe purpose of this study was to examine the associations between objectively measured physical activity and serum brain-derived neurotrophic factor (BDNF) in adolescents.MethodsCross-sectional analyses were performed using data from 415 adolescents who participated in the 2015 follow-up of the Childhood Health Activity and Motor Performance School Study Denmark (the CHAMPS-study DK). Physical activity was objectively measured by accelerometry monitors. Serum BDNF levels were analyzed using the Enzyme-linked immunosorbent assay (ELISA). Anthropometrics and pubertal status were measured using standardized procedures.ResultsWith adjustment for age, pubertal status and body mass index, mean physical activity (counts per minute) was negatively associated with serum BDNF in boys (P = 0.013). Similarly, moderate-to-vigorous physical activity (MVPA) was negatively associated with serum BDNF in boys (P = 0.035). In girls, mean physical activity and MVPA were not associated with serum BDNF. Without adjustment for wear time, sedentary time was not associated with serum BDNF in either sex.ConclusionThese findings indicate that higher physical activity is associated with lower serum BDNF in boys, but not in girls.