Longitudinal predictors of uremic pruritus.

OBJECTIVE: Pruritus is a common problem among hemodialyzed patients. Its causes are poorly understood, and, as a result, itching is often attributed to elevated serum phosphorus and other disorders of bone and minerals. The primary purpose of this study was to analyze the relationship between pruritus and common tests of bone and mineral disease. METHODS: This study was a post hoc analysis of data from a randomized controlled trial of 3 months of ergocalciferol versus placebo treatment in 50 hemodialysis patients with uremic pruritus. A pruritus survey was administered at baseline and then every 2 weeks for 12 weeks. Concurrent serum phosphorus, intact parathyroid hormone (PTH), serum calcium, and calcium-phosphate product were measured. RESULTS: Pruritus score was not found to be associated or correlated with serum phosphate, intact PTH, serum calcium, or calcium-phosphate product at each time interval or over time. Likewise, when analyzed by original study group (placebo or ergocalciferol), no association or correlation between the mineral and bone indicators and itching were found. CONCLUSION: Neither serum phosphate nor other tests of bone and mineral status were found to be significant predictors of pruritus at any point in time or over time.

The effect of ergocalciferol on uremic pruritus severity: a randomized controlled trial.

OBJECTIVE: Hemodialysis (HD) patients have a high prevalence of pruritus. 25-Hydroxy vitamin D deficiency is common in this population and may play a role in its etiology. Because of this, we studied whether vitamin D2 treatment with ergocalciferol is effective for relief of uremic pruritus severity as measured by pruritus severity surveys. DESIGN, SETTING, AND SUBJECTS: In this double-blind, placebo-controlled, randomized trial, the effect of 12 weeks of ergocalciferol administration on uremic pruritus severity was evaluated. INTERVENTION: Fifty HD patients randomly received either ergocalciferol 50,000 international units (IU) or placebo once weekly for 12 weeks. MAIN OUTCOME MEASURE: Pruritus severity surveys were completed every 2 weeks by all patients starting from baseline until 12 weeks and serve as the main outcome variable. RESULTS: Twenty-five study participants were randomized to ergocalciferol therapy and 25 were randomized to placebo. At baseline, the only significant difference between the two groups was time on dialysis and white blood cell count. Both groups experienced a decrease in pruritus scores from the beginning to the end of study (percent change -38.9% in the treatment group vs. -47.5% in the placebo group). By intention to treat, the treatment × time effect was not statistically significant (F = 0.71, df = (1, 282), P = .34), indicating that the pruritus score was not significantly lower in the treatment group than the placebo group throughout the study. CONCLUSION: In conclusion, we did not find ergocalciferol to be effective for the treatment of uremic pruritus.