title: Circulating C reactive protein in osteoarthritis: a systematic review and meta-analysis.
abstract: BACKGROUND
  There is emerging evidence that the development and progression of osteoarthritis (OA) is associated with inflammation. C reactive protein (CRP), a systemic marker for inflammation, may be elevated in OA patients but the evidence is conflicting.
  
  
  OBJECTIVE
  To systematically review the literature for the relationship between serum CRP levels measured by a high sensitivity method (high sensitive CRP (hs-CRP)) and OA, as well as the correlation between circulating CRP levels and OA phenotypes.
  
  
  METHODS
  MEDLINE, EMBASE and CINAHL databases were systematically searched from January 1992 to December 2012. Studies were included when they met the inclusion criteria and data from studies were extracted. Two independent reviewers assessed study quality using a modified Newcastle-Ottawa Quality Assessment Scale. Meta-analyses were performed to pool available data from included studies.
  
  
  RESULTS
  32 studies met the inclusion criteria. Serum hs-CRP levels in OA were modestly but statistically significantly higher than controls (mean difference=1.19 mg/L, 95% CI 0.64 to 1.73, p<0.001) with significant heterogeneity between studies. Levels were significantly associated with pain (r=0.14, 95% CI 0.09 to 0.20, p<0.001) and decreased physical function (r=0.25, 95% CI 0.13 to 0.39, p<0.001). No significant associations were found between hs-CRP levels and radiographic OA.
  
  
  CONCLUSIONS
  Low-grade systemic inflammation may play a greater role in symptoms rather than radiographic changes in OA.
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Xingzhong
authors.initials: X
authors.lastname: Jin
authors.affiliation: Department of Dermatology, Austral University Hospital, Buenos Aires, Argentina.
authors.forename: Julieta Ruiz
authors.initials: JR
authors.lastname: Beguerie
authors.affiliation: Academic Rheumatology, University of Nottingham, Nottingham, UK.
authors.forename: Weiya
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Leigh
authors.initials: L
authors.lastname: Blizzard
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Petr
authors.initials: P
authors.lastname: Otahal
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Graeme
authors.initials: G
authors.lastname: Jones
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia Arthritis Research Institute, 1st Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
authors.forename: Changhai
authors.initials: C
authors.lastname: Ding
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D010003:Osteoarthritis / Q000378:metabolism*; D010641:Phenotype
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein
keywords: Epidemiology; Inflammation; Osteoarthritis