title: Daytime sleepiness and the COMT val158met polymorphism in patients with Parkinson disease.
abstract: OBJECTIVE
  A preliminary study by our group suggested an association between daytime sleepiness and the catechol-O-methyltransferase (COMT) val158met polymorphism (rs4680) in patients with Parkinson disease (PD). We sought to confirm this association in a large group of patients with PD.
  
  
  METHODS
  Genetic association study in patients with PD.
  
  
  METHODS
  Movement disorder sections at 2 university hospitals.
  
  
  METHODS
  PD patients with and without episodes of suddenly falling asleep matched for antiparkinsonian medication, disease duration, sex, and age, who participated in a previous genetic study on dopamine-receptor polymorphisms.
  
  
  METHODS
  Not applicable.
  
  
  RESULTS
  In this study, 240 patients with PD (154 men; age 65.1 +/- 6.1 years; disease duration 9.4 +/- 6.0 years) were included. Seventy had the met-met (LL), 116 the met-val (LH), and 54 the val-val (HH) genotype. In the combined LL+LH group (featuring reduced COMT activity), the mean Epworth Sleepiness Scale (ESS) score was 9.0 +/- 5.9 versus 11.0 +/- 6.1 in the HH (high COMT activity) group (P = .047). Forty-seven percent of the LL and LH patients had sudden sleep onset compared with 61% of the HH patients (P = .07). Logistic regression, however, showed that both pathologic ESS scores (i.e., > 10) and sudden sleep onset were predicted by subjective disease severity (P < .001 each) but not by the COMT genotype.
  
  
  CONCLUSIONS
  Our previous finding that the L-allele may be associated with daytime sleepiness could not be confirmed in the present study. Altogether, our data do not support a clinically relevant effect of the COMT genotype on daytime sleepiness in PD.
authors.affiliation: Department of Neurology, Philipps-University Marburg, Germany.
authors.forename: Ida
authors.initials: I
authors.lastname: Rissling
authors.forename: Birgit
authors.initials: B
authors.lastname: Frauscher
authors.forename: Florian
authors.initials: F
authors.lastname: Kronenberg
authors.forename: Mehdi
authors.initials: M
authors.lastname: Tafti
authors.forename: Karin
authors.initials: K
authors.lastname: Stiasny-Kolster
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Robyr
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Körner
authors.forename: Wolfgang Hermann
authors.initials: WH
authors.lastname: Oertel
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
authors.forename: Birgit
authors.initials: B
authors.lastname: Högl
authors.forename: Jens Carsten
authors.initials: JC
authors.lastname: Möller
mesh_terms: D000368:Aged; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D002940:Circadian Rhythm; D003062:Codon; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology* / Q000235:genetics*; D004298:Dopamine / Q000235:genetics*; D018491:Dopamine Agonists / Q000627:therapeutic use; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy / Q000453:epidemiology*; D011110:Polymorphism, Genetic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D003062:Codon; D018491:Dopamine Agonists; D002394:Catechol O-Methyltransferase; D004298:Dopamine