# Metabolomic Analysis of Uremic Pruritus in Patients on Hemodialysis

## TL;DR

This study finds that uremic pruritus in hemodialysis patients is linked to metabolic and inflammatory factors, not dialysis-related variables.

## Contribution

The study identifies specific metabolic and inflammatory biomarkers as independent predictors of uremic pruritus in hemodialysis patients.

## Key findings

- Uremic pruritus was found in 29.2% of hemodialysis patients.
- Serum phosphate, uric acid, iPTH, and hs-CRP were significant independent predictors of pruritus.
- Metabolic and inflammatory factors, not demographic or dialysis variables, were most strongly associated with pruritus.

## Abstract

Background: Uremic pruritus (UP) is a prevalent and distressing complication among patients with end-stage renal disease (ESRD) receiving maintenance hemodialysis (HD). Despite its significant impact on quality of life and mortality, the underlying pathophysiology remains incompletely understood, with evidence implicating metabolic and inflammatory factors.

Objective: This study aimed to determine the prevalence of UP and assess its association with selected metabolic and inflammatory biomarkers in patients undergoing maintenance HD.

Methods: A cross-sectional observational study was conducted at the Dialysis Centre of Lahore General Hospital, a tertiary care hospital in Lahore, Pakistan. A total of 281 adult HD patients were enrolled. Pruritus was assessed using the 5-D Itch Scale, with a score ≥10 defining cases. Demographic and clinical data were recorded, and laboratory parameters including hemoglobin, calcium, phosphate, magnesium, intact parathyroid hormone (iPTH), uric acid, lipid profile, high-sensitivity C-reactive protein (hs-CRP), and white blood cell (WBC) count were analyzed. Associations were assessed using chi-square and independent samples t-tests. Multivariate logistic regression identified independent predictors of pruritus.

Results: The prevalence of UP was 82 (29.2%). Significant differences were observed between pruritic and non-pruritic groups in age, dialysis duration, and several biochemical parameters. Independent predictors of pruritus included advancing age (OR = 1.148, p < 0.001), serum phosphate (OR = 2.069, p < 0.001), uric acid (OR = 1.680, p < 0.001), iPTH (OR = 1.007, p < 0.001), hs-CRP (OR = 1.596, p = 0.001), magnesium (OR = 9.687, p = 0.020), triglycerides (OR = 1.018, p = 0.025), and HCV infection (OR = 8.098, p = 0.001). No significant associations were found with gender, diabetes, dialysis frequency, or vascular access.

Conclusion: UP in HD patients is significantly associated with metabolic and inflammatory derangements rather than demographic or dialysis-related variables. These findings underscore the importance of targeted metabolic control and inflammation modulation in managing pruritus among dialysis populations.