Sex-Specific associations of brain-derived neurotrophic factor and cardiorespiratory fitness in the general population

The brain-derived neurotrophic factor (BDNF) was initially considered to be neuron-specific. Meanwhile, this neurotrophin is peripherally also secreted by skeletal muscle cells and increases due to exercise. Whether BDNF is related to cardiorespiratory fitness (CRF) is currently unclear. We analyzed the association of serum BDNF levels with CRF in the general population (Study of Health in Pomerania (SHIP-TREND) from Northeast Germany; n = 1607, 51% female; median age 48 years). Sex-stratified linear regression models adjusted for age, height, smoking, body fat, lean mass, physical activity, and depression analyzed the association between BDNF and maximal oxygen consumption (VO2peak), maximal oxygen consumption normalized for body weight (VO2peak/kg), and oxygen consumption at the anaerobic threshold (VO2@AT). In women, 1mL/min higher VO2peak, VO2peak/kg, and VO2@AT were associated with a 2.43 pg/mL (95% confidence interval [CI]: 1.16 to 3.69 pg/mL; p = 0.0002), 150.66 pg/mL (95% CI: 63.42 to 237.90 pg/mL; p = 0.0007), and 2.68 pg/mL (95% CI: 0.5 to 4.8 pg/mL; p = 0.01) higher BDNF serum concentration, respectively. No significant associations were found in men. Further research is needed to understand the sex-specific association between CRF and BDNF. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

Sex-Specific Associations of Brain-Derived Neurotrophic Factor and Cardiorespiratory Fitness in the General Population

The brain-derived neurotrophic factor (BDNF) was initially considered to be neuron-specific. Meanwhile, this neurotrophin is peripherally also secreted by skeletal muscle cells and increases due to exercise. Whether BDNF is related to cardiorespiratory fitness (CRF) is currently unclear. We analyzed the association of serum BDNF levels with CRF in the general population (Study of Health in Pomerania (SHIP-TREND) from Northeast Germany; n = 1607, 51% female; median age 48 years). Sex-stratified linear regression models adjusted for age, height, smoking, body fat, lean mass, physical activity, and depression analyzed the association between BDNF and maximal oxygen consumption (VO2peak), maximal oxygen consumption normalized for body weight (VO2peak/kg), and oxygen consumption at the anaerobic threshold (VO2@AT). In women, 1mL/min higher VO2peak, VO2peak/kg, and VO2@AT were associated with a 2.43 pg/mL (95% confidence interval [CI]: 1.16 to 3.69 pg/mL; p = 0.0002), 150.66 pg/mL (95% CI: 63.42 to 237.90 pg/mL; p = 0.0007), and 2.68 pg/mL (95% CI: 0.5 to 4.8 pg/mL; p = 0.01) higher BDNF serum concentration, respectively. No significant associations were found in men. Further research is needed to understand the sex-specific association between CRF and BDNF. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

Assoziation zwischen Brain-derived neurotrophic factor und der kardiorespiratorischen Fitness in der Allgemeinbevölkerung

Der Wachstumsfaktor BDNF ist nicht allein neuronenspezifisch. Bisherige Studien zeigten einen starken Zusammenhang der BDNF-Konzentration mit körperlicher Aktivität sowie den Nachweis einer BDNF-Sekretion durch kontrahierende Skelettmuskelzellen. Weiterführend untersuchten nur wenige Studien den möglichen Zusammenhang zwischen der BDNF-Konzentration und der kardiorespiratorischen Fitness. Hier zeigten sich in den bisherigen Studien heterogene Ergebnisse, sodass der Zusammenhang zwischen BDNF und der kardiorespiratorischen Fitness weitestgehend ungeklärt ist. In unserer Analyse aus der Allgemeinbevölkerung (n = 1.607, 51 % weiblich) konnte in geschlechtsstratifizierten Regressionsmodellen gezeigt werden, dass nur bei Frauen eine erhöhte BDNF-Konzentration mit erhöhter VO2peak, VO2@AT sowie VO2peak/kg assoziiert sind. Eine mögliche Erklärung bisheriger heterogener Ergebnisse beruht auf unterschiedlichen Studienpopulationen mit auffällig geringem bis fehlendem Frauenanteil in bisherigen Studien, individueller Korrektur von Störfaktoren sowie individueller Erfassung der körperlichen Aktivität und kardiorespiratorischer Fitness. Zur Darstellung der geschlechtsspezifischen Ergebnisse zwischen BDNF und der kardiorespiratorischen Fitness bedarf es weiterer Untersuchungen. Beispielsweise gilt es spezifische Skelettmuskelfasertypen sowie den Einfluss der konkreten Östrogenmenge zu betrachten