title: Brain-derived neurotrophic factor and its relation to leptin in obese children before and after weight loss.
abstract: OBJECTIVE
  Brain-derived neurotrophic factor (BDNF) is a regulator of energy homeostasis and food intake through hypothalamic signaling. Currently, data regarding BDNF in children with obesity are lacking. We evaluated serum BDNF concentrations in obese children, both before and after lifestyle intervention, in reference to those of lean children.
  
  
  METHODS
  A total of 90 (24 normal weight; 66 obese) children were studied utilizing a cross-sectional clinical outpatient study design. In addition, longitudinal data analysis was performed in 30 obese children participating in a lifestyle intervention for one year.
  
  
  RESULTS
  Fasting serum BDNF concentrations were higher in obese vs. normal weight children (BDNF 20.3±1.0 vs. 12.5±1.7 ng/mL, respectively, mean±SEM, p<0.001) and correlated significantly to BMI standard deviation score (r=0.426, p<0.001), and leptin (r=0.414, p<0.01). BDNF concentrations were not regulated in response to food, 60 min after ingestion of a liquid test meal. After one year lifestyle intervention, delta BDNF correlated significantly to delta leptin (r=0.475, p<0.01), but not to changes of insulin resistance index HOMA-IR, systolic and diastolic blood pressure, HDL, LDL, and triglycerides. In a multiple stepwise linear regression adjusted for pubertal stage, age, sex, and BMI, delta BDNF correlated significantly (p<0.05) to delta leptin and delta triceps skinfold and in tendency to delta subscapularis skinfold thickness (p=0.050).
  
  
  CONCLUSIONS
  Our results in children do not indicate a significant relationship between BDNF and insulin resistance or cardiovascular risk factors. However, the correlation between changes of BDNF and changes of leptin suggests a relationship between BDNF and fat mass.
authors.affiliation: Seattle Children's Hospital Research Institute, Seattle, WA 98101, USA. christian.roth@seattlechildrens.org
authors.forename: Christian L
authors.initials: CL
authors.lastname: Roth
authors.forename: Clinton
authors.initials: C
authors.lastname: Elfers
authors.forename: Ursel
authors.initials: U
authors.lastname: Gebhardt
authors.forename: Hermann L
authors.initials: HL
authors.lastname: Müller
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinehr
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D002648:Child; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D020738:Leptin / Q000097:blood*; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000097:blood*; D014280:Triglycerides / Q000097:blood; D015431:Weight Loss / Q000502:physiology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020738:Leptin; D014280:Triglycerides; D002784:Cholesterol