title: Physical exercise counteracts genetic susceptibility to depression.
abstract: OBJECTIVE
  Depression is a highly prevalent disorder in elderly individuals. A genetic variant (rs6265) of the brain-derived neurotrophic factor (BDNF) impacting on emotion processing is known to increase the risk for depression. We aim to investigate whether intensive endurance sports might attenuate this genetic susceptibility in a cohort of elderly marathon athletes.
  
  
  METHODS
  Fifty-five athletes and 58 controls were included. rs6265 of the BDNF gene was genotyped by the TaqMan method. Depressive symptoms were assessed by standardized self-rating tests (BDI = Beck Depression Inventory, GDS = Geriatric Depression Scale).
  
  
  RESULTS
  In multivariable analysis of BDI and GDS scores, the interaction between group (athletes vs. controls) and genotypes ([C];[C] vs. [C];[T] + [T];[T]) was found to be statistically significant (BDI: p = 0.027, GDS: p = 0.013). Among [C];[C] carriers, merely controls had an increased relative risk of 3.537 (95% CI = 1.276-9.802) of achieving a subclinical depression score ≥10 on the BDI. There was no such effect in carriers of the [T] allele. In a multivariable binary logistic regression, genetic information, group (athletes/controls), but no information on rs6265 allele carrier status presented as a significant predictor of BDI scores ≥10.
  
  
  CONCLUSIONS
  Physical exercise positively affects BDNF effects on mood. Since 66Met BDNF secretion is impaired, this effect seems to be much stronger in [C];[C] homozygous individuals expressing the 66Val variant. This confirms that genetic susceptibility to depressive symptoms can indeed be influenced by endurance sports in elderly people.
authors.affiliation: Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Helmuth
authors.initials: H
authors.lastname: Haslacher
authors.forename: Matthias
authors.initials: M
authors.lastname: Michlmayr
authors.forename: Delgerdalai
authors.initials: D
authors.lastname: Batmyagmar
authors.forename: Thomas
authors.initials: T
authors.lastname: Perkmann
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ponocny-Seliger
authors.forename: Vanessa
authors.initials: V
authors.lastname: Scheichenberger
authors.forename: Alexander
authors.initials: A
authors.lastname: Pilger
authors.forename: Peter
authors.initials: P
authors.lastname: Dal-Bianco
authors.forename: Johann
authors.initials: J
authors.lastname: Lehrner
authors.forename: Lukas
authors.initials: L
authors.lastname: Pezawas
authors.forename: Oswald
authors.initials: O
authors.lastname: Wagner
authors.forename: Robert
authors.initials: R
authors.lastname: Winker
mesh_terms: D000368:Aged; D056352:Athletes; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D003863:Depression / Q000097:blood / Q000235:genetics* / Q000517:prevention & control* / Q000523:psychology; D015444:Exercise; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics* / Q000517:prevention & control* / Q000523:psychology; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011581:Psychological Tests; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human