Elevated C-reactive protein level in hemodialysis patients with moderate/severe uremic pruritus: a potential mediator of high overall mortality

QJM. 2010 Nov;103(11):837-46. doi: 10.1093/qjmed/hcq036. Epub 2010 Mar 29.

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).

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Analysis of Variance
  • Biomarkers / metabolism
  • C-Reactive Protein / metabolism*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prognosis
  • Prospective Studies
  • Pruritus / blood*
  • Pruritus / mortality
  • Renal Dialysis / mortality*
  • Severity of Illness Index
  • Survival Rate
  • Treatment Outcome
  • Tumor Necrosis Factor-alpha / blood
  • Uremia / blood
  • Uremia / mortality*

Substances

  • Biomarkers
  • Tumor Necrosis Factor-alpha
  • C-Reactive Protein