title: Lack of association between asymmetric dimethylarginine and in vivo microvascular and macrovascular endothelial function in patients with rheumatoid arthritis.
abstract: OBJECTIVE
  The aim of the present study was to investigate if assymetric dimethylarginine (ADMA) is increased in patients with rheumatoid arthritis (RA) compared to healthy controls and to examine associations between ADMA, RA disease activity and in vivo assessments of microvascular and macrovascular endothelial function.
  
  
  METHODS
  Sixty-seven RA patients (age [mean ± standard deviation]: 56 ± 12 years, disease duration median [25th-75th percentile]: 8 [3-15] years, 48 women) and 29 healthy controls (age [mean ± standard deviation]: 42 ± 12, 21 women) underwent assessments of microvascular endothelial function (Laser Doppler imaging with iontophoresis of acetylcholine and sodium-nitroprusside), and macrovascular endothelial function (flow-mediated dilatation and glyceryl-trinitrate-mediated dilatation) as well as arterial stiffness. ADMA levels were measured in contemporary specimens using an immunoassay ELISA kit.
  
  
  RESULTS
  ADMA levels were significantly higher (p=0.004) in RA patients compared with healthy controls after adjustment for age (difference=0.088, 95% confidence interval 0.029-0.147). ADMA levels did not correlate with demographic or disease characteristics. No correlation was found between ADMA and microvascular and macrovascular endothelial function or with arterial stiffness.
  
  
  CONCLUSIONS
  ADMA levels are increased in patients with RA but there was no significant correlation with in vivo assessments of endothelial function. Further studies are needed to unfold the pathophysiological role of nitric oxide/ADMA pathway derangement in endothelial dysfunction and cardiovascular risk in RA.
authors.affiliation: Department of Rheumatology, Dudley Group of Hospitals NHS Trust, Russells Hall Hospital, Dudley, West Midlands, UK. aamer.sandoo@dgh.nhs.uk
authors.forename: A
authors.initials: A
authors.lastname: Sandoo
authors.forename: T
authors.initials: T
authors.lastname: Dimitroulas
authors.forename: J J C S
authors.initials: JJ
authors.lastname: Veldhuijzen van Zanten
authors.forename: J P
authors.initials: JP
authors.lastname: Smith
authors.forename: G S
authors.initials: GS
authors.lastname: Metsios
authors.forename: P
authors.initials: P
authors.lastname: Nightingale
authors.forename: A
authors.initials: A
authors.lastname: Stavropoulos-Kalinoglou
authors.forename: G D
authors.initials: GD
authors.lastname: Kitas
mesh_terms: D000328:Adult; D000368:Aged; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D004730:Endothelium, Vascular / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000378:metabolism / Q000503:physiopathology; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood; D012307:Risk Factors; D012720:Severity of Illness Index; D014652:Vascular Diseases / Q000097:blood* / Q000453:epidemiology*; D059289:Vascular Stiffness / Q000502:physiology
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide; C024917:symmetric dimethylarginine; D001120:Arginine