Uremic pruritus is associated with higher Kt/V and serum calcium concentration

Abstract

BACKGROUND: The prevalence and characteristics of uremic pruritus have not recently been investigated in a US dialysis cohort. This study examined uremic pruritus and associated risk factors in hemodialysis patients treated in the year 2005. METHODS: The prevalence and characteristics of pruritus (short version McGill pain questionnaire), severity (10 cm visual analogue scale), and effect on quality of life (Skindex-16) were determined in thrice weekly hemodialysis patients. Daugirdas single-pool Kt/V, clinical and laboratory data were recorded. RESULTS: 105 of 307 screened hemodialysis patients met inclusion criteria and were evaluated, 49% (151) were excluded due to advanced age, 3% (9) other skin diseases, and 14% (42) refused. Participants were 55% male (58/105) and 65% African-American (68) with a mean +/- SD age of 48 +/- 11 years. The overall prevalence of pruritus was 57% (60/105, 95% CI 47 - 67%) and a positive correlation was observed between the presence of uremic itch and serum calcium concentration (p = 0.04). Intact PTH and serum phosphorus concentration were not associated with either the presence or intensity of itch. Intensity of pruritus was positively correlated with increasing months on dialysis (64 +/- 63 vs. 51 +/- 46 months for itch and non-itch, respectively; p = 0.02), higher Kt/V (1.82 +/- 0.7 vs. 1.70 +/- 0.56 for itch and non-itch, respectively; p = 0.01) and skin dryness (p = 0.01). Patients receiving statins were significantly less likely to report pruritus (p = 0.02) and uremic itch adversely impacted several aspects of quality of life. CONCLUSIONS: Pruritus remains a common and significant symptom in adequately hemodialyzed patients. Higher serum calcium concentrations, longer durations of ESRD and higher Kt/V appear to be important factors associated with uremic pruritus.