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

Abstract

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. 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. 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. 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.