Plasma Brain-Derived Neurotrophic Factor (BDNF) Concentrations in Children and Adolescents

Background:BDNF is a mediator of neuronal plasticity and influences learning, memory, cognitive behaviour and reproductive system.Objective:Aim of this study is to assess BDNF concentrations in healthy children and adolescents according to pubertal status.Methods:One hundred ten health children, adolescents and young adults were recruited. BDNF concentrations were measured by ELISA.Platelet count (PTL), estradiol (E2), testosterone (T), and IGF-1 were also assessed. Non parametric statistical analysis was performed.The association between potential predictors and BDNF values was evaluated throught multivariate logistic regression model [sex, age,height SDS, z-BMI, pubertal status (no/yes), PTL, E2, T]Results:The characteristics of the patients are reported in the Table. Girls displayed higher BDNF levels than boys. BDNF concentrationswere not significantly different between prepubertal and pubertal subjects while its levels resulted lower in pubertal boys than pubertalones and both prepubertal and pubertal girls (x2=9.74; Kruskal-Wallis test= 8.52; p = 0.036). We have found a significant correlationbetween the values of BDNF and PTL (r=0.333; p=0.007), chronological age (r=-0.225; p=0.019), height (r=-0.231; p=0.016), and T (r=-0.261; p=0.006) . In prepubertal group BDNF values were correlated only with PTL (r=0.325; p=0.025), while in pubertal subjects they were correlated with z-BMI (r=0.293; p=0.038). The main predictor of BDNF was PTL (r=0.357, p=0.008).Conclusions:Our data suggests that serum BDNF is positively correlated with both platelet count and z-BMI and negatively associated with age. Thus, serum BDNF concentrations in children may need to be interpreted with age-specific and platelet count-specific standards. BDNF level was partially explained by PTL (R2=22%), but other parameters are probably involved in its determination (BMI, puberty). Furher studies are necessary to better understand the role of this neurotrophin, expressed in the central and peripheral nervous system, in pediatric subjects.