title: Serum nitrate and nitrite levels in patients with rheumatoid arthritis, ankylosing spondylitis, and osteoarthritis.
abstract: OBJECTIVE
  To assess and compare serum nitrate and nitrite levels in patients with ankylosing spondylitis (AS), rheumatoid arthritis (RA), and osteoarthritis (OA).
  
  
  METHODS
  Thirty five patients with RA, 32 patients with AS, and 36 patients with OA were entered into this study. In addition, 30 healthy volunteers acted as a control group. Concentrations of nitrate and nitrite in serum were determined by direct and indirect Griess reactions. C reactive protein and erythrocyte sedimentation rate levels were determined as markers of systemic activity of disease (SAD) in RA and AS groups.
  
  
  RESULTS
  Serum nitrate and nitrite levels were found to be higher in patients with AS and RA than in the OA group (p<0.01). In addition, serum nitrate and nitrite levels were higher in all three groups than in the control group (p<0.01). Moreover, serum nitrate and nitrite levels were higher in patients who had SAD than in those who had not in the RA and AS groups (p<0.01 and p<0.05, respectively), and there was a correlation between serum nitrate and nitrite concentrations and SAD variables in patients with RA (Spearman's r(s)=0.414, p<0.05 and r(s)=0.408, p<0.05, respectively) and AS (r(s)=0.421, p<0.05 and r(s)=0.412, p<0.05, respectively).
  
  
  CONCLUSIONS
  The findings suggest that nitrate and nitrite production is enhanced in patients with inflammatory arthritis compared with OA. In addition, serum nitrate and nitrite levels are enhanced in patients with RA, AS, and OA compared with healthy subjects. Furthermore, there is a correlation between the SAD variables and serum nitrate and nitrite levels in patients with RA and AS.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Inonu University Faculty of Medicine, Turgut Ozal Medical Centre, 44069 Malatya, Turkey. dryuksel@hotmail.com
authors.forename: Y
authors.initials: Y
authors.lastname: Ersoy
authors.forename: E
authors.initials: E
authors.lastname: Ozerol
authors.forename: O
authors.initials: O
authors.lastname: Baysal
authors.forename: I
authors.initials: I
authors.lastname: Temel
authors.forename: R S
authors.initials: RS
authors.lastname: MacWalter
authors.forename: U
authors.initials: U
authors.lastname: Meral
authors.forename: Z E
authors.initials: ZE
authors.lastname: Altay
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood*; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood*; D009573:Nitrites / Q000097:blood*; D010003:Osteoarthritis / Q000097:blood*; D013167:Spondylitis, Ankylosing / Q000097:blood*; D018709:Statistics, Nonparametric
chemical_list: D009566:Nitrates; D009573:Nitrites; D002097:C-Reactive Protein