title: Endothelial dysfunction and hyperhomocysteinemia in Parkinson's disease: flow-mediated dilation study.
abstract: BACKGROUND
  Levodopa (l-dopa) therapy in Parkinson's disease (PD) increases serum homocysteine levels because of its metabolism via catechol O-methyltransferase, which may lead to endothelial dysfunction.
  
  
  METHODS
  We enrolled 40 PD patients treated with l-dopa, 33 PD patients treated with l-dopa/entacapone, 22 untreated PD and 30 controls, and compared the flow-mediated dilation in these subjects.
  
  
  RESULTS
  The flow-mediated dilation was significantly lower in PD patients with l-dopa (6.0 ± 1.8%) than in those with l-dopa/entacapone (7.2 ± 1.1%, P = 0.03), untreated PD patients (7.8 ± 1.2%, P < 0.05), and controls (8.5 ± 2.9%, P < 0.05). The homocysteine level was significantly higher in PD patients with l-dopa than in other groups. In a multivariate logistic regression model, the uppermost homocysteine quartile was an independent predictor of the lowest tertile of flow-mediated dilation (odds ratio, 6.33; 95% confidence interval, 1.61-26.65; P = 0.012).
  
  
  CONCLUSIONS
  Our findings indicate that endothelial dysfunction may be associated with chronic l-dopa treatment in patients with PD.
authors.affiliation: Department of Neurology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Jung Han
authors.initials: JH
authors.lastname: Yoon
authors.forename: Jin Soo
authors.initials: JS
authors.lastname: Lee
authors.forename: Seok Woo
authors.initials: SW
authors.lastname: Yong
authors.forename: Ji Man
authors.initials: JM
authors.lastname: Hong
authors.forename: Phil Hyu
authors.initials: PH
authors.lastname: Lee
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D001916:Brachial Artery / Q000187:drug effects / Q000503:physiopathology; D002396:Catechols / Q000627:therapeutic use; D004106:Dilatation; D004727:Endothelium / Q000187:drug effects / Q000473:pathology*; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000175:diagnosis / Q000209:etiology*; D007980:Levodopa / Q000627:therapeutic use; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009570:Nitriles / Q000627:therapeutic use; D010300:Parkinson Disease / Q000097:blood / Q000150:complications* / Q000473:pathology*; D018709:Statistics, Nonparametric
chemical_list: D000978:Antiparkinson Agents; D002396:Catechols; D009570:Nitriles; D006710:Homocysteine; D007980:Levodopa; C071192:entacapone
keywords: Parkinson's disease; endothelial dysfunction; flow-mediated dilation; hyperhomocysteinemia