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. (C) 2013 by the National Kidney Foundation, Inc. All rights reserved.