title: Cystatin C, renal function, and atherosclerosis in rheumatoid arthritis.
abstract: OBJECTIVE
  We examined the hypothesis that cystatin C, a novel marker of renal function, is elevated in rheumatoid arthritis (RA) and is associated with inflammation and coronary atherosclerosis.
  
  
  METHODS
  We measured serum cystatin C, creatinine, tumor necrosis factor-α and interleukin 6 concentrations, coronary artery calcium score (CACS), and Modified Diet in Renal Disease estimated glomerular filtration rate in 167 patients with RA and 91 controls.
  
  
  RESULTS
  Cystatin C was higher in RA patients [median (IQR) 1.16 (0.99-1.35) mg/l] than controls [1.01 (0.90-1.19) mg/l; p < 0.001] and correlated positively with erythrocyte sedimentation rate (p < 0.001), C-reactive protein (p = 0.01), 28-joint Disease Activity Score (p = 0.006), and Framingham risk score (FRS; p = 0.02). Cystatin C was correlated with CACS (p < 0.001) in RA, but this was not significant after adjustment for age, race, sex, and FRS (p = 0.44).
  
  
  CONCLUSIONS
  Cystatin C concentrations are higher in RA than controls and may reflect inflammation and undetected subclinical renal dysfunction. Cystatin C provides information regarding the risk of atherosclerosis in RA, but this is not independent of the information provided by conventional cardiovascular risk factors.
authors.affiliation: Divisions of Clinical Pharmacology and Rheumatology, School of Medicine, Vanderbilt University, Nashville, TN 37232-6602, USA.
authors.forename: Ratchaya
authors.initials: R
authors.lastname: Lertnawapan
authors.forename: Aihua
authors.initials: A
authors.lastname: Bian
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Rho
authors.forename: Vivian K
authors.initials: VK
authors.lastname: Kawai
authors.forename: Paolo
authors.initials: P
authors.lastname: Raggi
authors.forename: Annette
authors.initials: A
authors.lastname: Oeser
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Solus
authors.forename: Tebeb
authors.initials: T
authors.lastname: Gebretsadik
authors.forename: Ayumi
authors.initials: A
authors.lastname: Shintani
authors.forename: C Michael
authors.initials: CM
authors.lastname: Stein
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000150:complications*; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000378:metabolism; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000453:epidemiology*; D003331:Coronary Vessels / Q000378:metabolism; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D007668:Kidney / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D003404:Creatinine; D002118:Calcium