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

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 alpha (TNF-alpha) 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-alpha 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) x (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.