title: Uric acid is a strong independent predictor of renal dysfunction in patients with rheumatoid arthritis.
abstract: BACKGROUND
  Recent evidence suggests that uric acid (UA), regardless of crystal deposition, may play a direct pathogenic role in renal disease. We have shown that UA is an independent predictor of hypertension and cardiovascular disease (CVD), and that CVD risk factors associate with renal dysfunction, in patients with rheumatoid arthritis (RA). In this study we investigated whether UA associates with renal dysfunction in patients with RA and whether such an association is independent or mediated through other comorbidities or risk factors for renal impairment.
  
  
  METHODS
  Renal function was assessed in 350 consecutive RA patients by estimated glomerular filtration rate (GFR) using the six-variable Modification of Diet in Renal Disease equation. Risk factors for renal dysfunction were recorded or measured in all participants. Linear regression was used to test the independence of the association between GFR and UA.
  
  
  RESULTS
  Univariable analysis revealed significant associations between GFR and age, systolic blood pressure, total cholesterol, triglycerides, RA duration and UA. UA had the most powerful association with renal dysfunction (r = -0.45, P < 0.001). A basic model was created, incorporating all of the above parameters along with body mass index and gender. UA ranked as the first correlate of GFR (P < 0.001) followed by age. Adjustments for the use of medications (diuretics, low-dose aspirin, cyclooxygenase II inhibitors and nonsteroidal anti-inflammatory drugs) and further adjustment for markers of inflammation and insulin resistance did not change the results.
  
  
  CONCLUSIONS
  UA is a strong correlate of renal dysfunction in RA patients. Further studies are needed to address the exact causes and clinical implications of this new finding. RA patients with elevated UA may require screening for renal dysfunction and appropriate management.
authors.affiliation: Department of Rheumatology, Dudley Group of Hospitals NHS Trust, Russells Hall Hospital, Pensnett Road, Dudley, West Midlands, UK. jimdaoussis@hotmail.com
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Daoussis
authors.forename: Vasileios
authors.initials: V
authors.lastname: Panoulas
authors.forename: Tracey
authors.initials: T
authors.lastname: Toms
authors.forename: Holly
authors.initials: H
authors.lastname: John
authors.forename: Ioannis
authors.initials: I
authors.lastname: Antonopoulos
authors.forename: Peter
authors.initials: P
authors.lastname: Nightingale
authors.forename: Karen M J
authors.initials: KM
authors.lastname: Douglas
authors.forename: Rainer
authors.initials: R
authors.lastname: Klocke
authors.forename: George D
authors.initials: GD
authors.lastname: Kitas
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood / Q000150:complications*; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000097:blood / Q000150:complications*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014527:Uric Acid / Q000097:blood*
chemical_list: D014527:Uric Acid