title: Elevated C-reactive protein level in hemodialysis patients with moderate/severe uremic pruritus: a potential mediator of high overall mortality.
abstract: BACKGROUND
  Dialysis patients with uremic pruritus have worse outcomes. However, the pathophysiology of the high mortality in these patients remains inconclusive except for links with calcium/phosphate imbalance and sleep disturbance. Whether inflammation, an outcome predictor in dialysis patients, plays a role is unknown.
  
  
  METHODS
  This prospective study included 321 chronic hemodialysis (HD) patients (>3 months) for survival analysis. A visual analog scale (VAS) was used to measure the severity of itching, and the patients were divided into four groups: no pruritus (VAS = 0, N = 118), mild (VAS 1-3, N = 76), moderate (VAS 4-7, N = 89) and severe pruritus (VAS 8-10, N = 38). The Pittsburgh Sleep Quality Index (PSQI) was used to define sleep disturbance, while high-sensitive C-reactive protein (hs-CRP) and tumor necrosis factor α (TNF-α) were used to evaluate inflammation. The patients were followed-up for 30 months.
  
  
  RESULTS
  Patients with moderate/severe pruritus had higher hs-CRP, but similar TNF-α levels; they also had a worse survival rate (P = 0.0197, log rank test). By stratifying hs-CRP levels, those with higher hs-CRP had worse survival regardless of the severity of uremic pruritus. In a Cox proportional hazard model, hs-CRP levels and moderate/severe uremic pruritus were independent predictors of mortality after adjusting for age, poor sleeper (PSQI > 5), diabetes, albumin, phosphate, hemoglobin and parathyroid hormone levels and (hs-CRP) × (moderate/severe uremic pruritus) (all P < 0.05).
  
  
  CONCLUSIONS
  In moderate/severe pruritic HD patients, those with higher hs-CRP suffer from worse overall mortality. Inflammation may bridge uremic pruritus to high mortality, and elevated hs-CRP predicts a worse outcome in this population.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Far Eastern Memorial Hospital, Pan-Chiao, Taipei, Taiwan.
authors.forename: H-Y
authors.initials: HY
authors.lastname: Chen
authors.forename: Y-L
authors.initials: YL
authors.lastname: Chiu
authors.forename: S-P
authors.initials: SP
authors.lastname: Hsu
authors.forename: M-F
authors.initials: MF
authors.lastname: Pai
authors.forename: C-F
authors.initials: CF
authors.lastname: Lai
authors.forename: J-Y
authors.initials: JY
authors.lastname: Yang
authors.forename: Y-S
authors.initials: YS
authors.lastname: Peng
authors.forename: T-J
authors.initials: TJ
authors.lastname: Tsai
authors.forename: K-D
authors.initials: KD
authors.lastname: Wu
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011537:Pruritus / Q000097:blood* / Q000401:mortality; D006435:Renal Dialysis / Q000401:mortality*; D012720:Severity of Illness Index; D015996:Survival Rate; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014511:Uremia / Q000097:blood / Q000401:mortality*
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein