title: Inflammation as a Risk of Developing Chronic Kidney Disease in Rheumatoid Arthritis.
abstract: OBJECTIVE
  The relationship between chronic inflammation and the incidence of chronic kidney disease (CKD) remained not-clear in patients with rheumatoid arthritis (RA). This study aims to examine the relationship between persistently high C-reactive protein (CRP), a marker of inflammation, and the incidence of CKD in RA.
  
  
  METHODS
  We retrospectively examined the relationship between the levels of CRP and incidence of CKD in 345 RA patients. The outcome of interest was incidence of CKD, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 and/or positive dipstick testing for proteinuria for ≥3 months. We defined high CRP, as >3.0 mg/L. On the basis of three measurements of CRP for 6-months period, patients were divided into three groups: group 1, including patients with no high CRP values; group 2, patients with transient high CRP values (once or twice) and group 3, patients with persistently high CRP values.
  
  
  RESULTS
  During a median follow-up period of 89 months, 14% of all patients developed CKD. The cumulative incidence of CKD was 7% in group 1, 14% in group 2 and 22% in group 3 (P = 0.008, log-rank test). In a multivariate analysis, including classical risk factors for CKD, persistently high CRP was an independent predictor of the incidence of CKD (hazard ratio, 3.00; 95% confidence interval, 1.23-8.53; P = 0.01).
  
  
  CONCLUSIONS
  Persistently high CRP was a significant risk factor for the incidence of CKD. Results suggest that persistent inflammation is a marker for the high risk of CKD in RA.
authors.affiliation: Department of Cardiovascular Medicine, Nephrology and Neurology, University of the Ryukyus School of Medicine, Nishihara, Okinawa, Japan.|Yuuaikai Nanbu Hospital, Itoman, Okinawa, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Kochi
authors.affiliation: Dialysis Unit, University Hospital of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kohagura
authors.affiliation: Yuuaikai Tomishiro Central Hospital, Tomigusuku, Okinawa, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Shiohira
authors.affiliation: Yuuaikai Tomishiro Central Hospital, Tomigusuku, Okinawa, Japan.|Okinawa Heart and Renal Association, Naha, Okinawa, Japan.
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Iseki
authors.affiliation: Yuuaikai Nanbu Hospital, Itoman, Okinawa, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohya
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000150:complications*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D051436:Renal Insufficiency, Chronic / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein