title: The COMT val(158)met polymorphism in ultra-endurance athletes.
abstract: Chronic levels of physical activity have been associated with increased dopamine (D2) receptors resulting in increased sensitivity to dopamine release. The catechol-O-methyltransferase enzyme, responsible for dopamine degradation, contains a functional polymorphism, which plays an important role in dopamine regulation within the prefrontal cortex. This polymorphism has previously been shown to affect human cognition and personality. However, the effect of this polymorphism has not been shown in ultra-endurance athletes.
  
  
  OBJECTIVE
  To examine the association of the COMT val(158)met variant with personality traits (harm avoidance, novelty seeking, reward dependence, resilience) and psychological distress (K10) of habitual physically active Ironman athletes compared to recreationally active controls.
  
  
  METHODS
  51 ultra-endurance Ironman athletes and 56 recreationally active controls were genotyped for the catechol-O-methyltransferase val(158)met polymorphism. Of the 107 participants, 55 ultra-endurance athletes and 32 recreationally active controls completed online personality questionnaires (harm avoidance, novelty seeking, reward dependence, resilience) and a psychological distress questionnaire (K10).
  
  
  RESULTS
  The personality trait, harm avoidance (p=0.001) and psychological distress (p=0.003) were significantly lower in Ironman athlete participants. Novelty seeking was significantly higher (p=0.02) in Ironman athlete participants with a significantly higher (p=0.04) score in Met(158) homozygous allele carriers.
  
  
  CONCLUSIONS
  Chronic levels of physical activity, as seen in ultra-endurance athletes, show increased novelty seeking scores in Met(158) homozygous allele carriers.
authors.affiliation: Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, South Africa. Electronic address: keelyn6@gmail.com.
authors.forename: Keelyn
authors.initials: K
authors.lastname: van Breda
authors.affiliation: Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, South Africa.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Collins
authors.affiliation: Department of Psychiatry, MRC Unit on Anxiety & Stress Disorders, University of Cape Town, South Africa.
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Stein
authors.affiliation: Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, South Africa.
authors.forename: Laurie
authors.initials: L
authors.lastname: Rauch
mesh_terms: D000328:Adult; D056352:Athletes / Q000523:psychology*; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005787:Gene Frequency; D060005:Genotyping Techniques; D006579:Heterozygote; D006801:Humans; D008297:Male; D010551:Personality / Q000235:genetics*; D010556:Personality Tests; D010807:Physical Endurance / Q000235:genetics*; D011110:Polymorphism, Genetic; D011594:Psychometrics; D044465:White People / Q000235:genetics
chemical_list: C588010:COMT protein, human; D002394:Catechol O-Methyltransferase
keywords: Behavior; Catechol-o-methyltransferase; Novelty seeking; Ultra-endurance