No change between the serum brain-derived neurotrophic factor in female patients with anorexia nervosa before and after partial weight recovery.
BACKGROUND
Brain-derived neurotrophic factor (BDNF) is a member of the nerve growth factor family. Several lines of evidence indicate that BDNF plays a role in the pathophysiology of eating disorders (ED). We found that serum BDNF levels in patients with ED were significantly lower than in normal controls. The aim of this longitudinal study was to compare serum BDNF levels in patients with anorexia nervosa (AN) before (n=13, initial mean body mass index (BMI)=14.2 kg/m(2)+/-0.7) and after partial recovery (mean BMI=16.2 kg/m(2)+/-1.7, mean weight gain 5.0 kg+/-2.0), with age-matched normal control subjects (n=17, mean BMI=20.4 kg/m(2)+/-1.5).


METHODS
Eating related psychopathology and depressive symptoms were evaluated before and after partial weight recovery, using the Eating Disorder Inventory-2 (EDI-2) and the 17-item Hamilton Depression Rating Scale (HDRS). Serum BDNF levels were measured using a sandwich enzyme-linked immunosorbent assay.


RESULTS
Serum BDNF levels with the AN patients (14.5+/-4.4 ng/ml) were significantly (p<0.01) lower than in control subjects (22.1+/-8.9 ng/ml). There were no significant differences in serum BDNF levels between the patients with AN before (14.5+/-4.4 ng/ml) and after (17.2+/-6.9 ng/ml) partial weight recovery. In all subjects, there was a positive correlation (r=0.5, p<0.01) between the baseline BDNF levels and the EDI-2 scores (n=30). Furthermore, in all subjects there was a positive correlation (r=0.4, p<0.05) between the BDNF levels and the BMI.


CONCLUSIONS
Serum BDNF levels did not change after partial weight recovery in AN patients. Our results suggest that an alteration of the serum BDNF in AN patients is not due to changes in body weight. Thus, other possible mechanisms that could be related to low serum BDNF levels in AN patients should be evaluated.
Nakazato
Michiko
M
Department of Psychiatry, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba City, Chiba, 260-8670, Japan. nakazato@faculty.chiba-u.jp
Hashimoto
Kenji
K
Yoshimura
Kazuyuki
K
Hashimoto
Tasuku
T
Shimizu
Eiji
E
Iyo
Masaomi
M
D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000097:blood* / Q000523:psychology / Q000628:therapy*; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003863:Depression / Q000523:psychology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D011569:Psychiatric Status Rating Scales; D015430:Weight Gain / Q000502:physiology
D019208:Brain-Derived Neurotrophic Factor