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

• Published in: QJM : An International Journal of Medicine 2010-11, Vol.103 (11), p.837-846
• Main Authors: Chen, H.-Y., Chiu, Y.-L., Hsu, S.-P., Pai, M.-F., Lai, C.-F., Yang, J.-Y., Peng, Y.-S., Tsai, T.-J., Wu, K.-D.
• Format: Article
• Language: English
• Subjects: Aged; Analysis of Variance; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Biomarkers - metabolism; C-Reactive Protein - metabolism; Emergency and intensive care: renal failure. Dialysis management; Female; Follow-Up Studies; General aspects; Humans; Intensive care medicine; Male; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; Predictive Value of Tests; Prognosis; Prospective Studies; Pruritus - blood; Pruritus - mortality; Renal Dialysis - mortality; Renal failure; Severity of Illness Index; Survival Rate; Treatment Outcome; Tumor Necrosis Factor-alpha - blood; Uremia - blood; Uremia - mortality
• ISSN: 1460-2725; 1460-2393
• DOI: 10.1093/qjmed/hcq036

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.