Incidence and Risk Factors for Pruritus in Patients with Nondialysis CKD

Background:Pruritus is a common symptom experienced by patients with nondialysis CKD, but risk factors for incident pruritus in this patient population have not been evaluated.Methods:We identified 1,951 participants with CKD in the Chronic Renal Insufficiency Cohort Study without pruritus at the baseline assessment. Pruritus was assessed by the Kidney Disease Quality of Life-36 instrument, and moderate-to-severe pruritus was defined as a response of 3 or higher on a Likert scale of 1 to 5. We used time-updated multivariable joint models to evaluate the association of patient clinical characteristics, eGFR, and laboratory parameters with incident pruritus.Results:Over a median follow-up of 6 years, 660 (34%) participants developed incident moderate-to-severe pruritus, with a higher incidence rate observed among participants with more advanced CKD. In multivariable models, the hazard ratio (95% CI) for pruritus associated with a 10 mL/min/1.73 m2lower eGFR was 1.16 (1.10 - 1.23). Older age (≥65 years), higher body mass index, diabetes, current smoking, opioid use, depressive symptoms, and serum parathyroid hormone were also associated with a higher risk of incident pruritus, while low serum calcium (<9 mg/dL) was associated with a lower risk (allp<0.05). Serum phosphate was not associated with incident pruritus in the primary analysis.Conclusions:A substantial proportion of patients with nondialysis CKD develop moderate-to-severe pruritus. While lower eGFR is associated with the risk of pruritus, other comorbidities, particularly depressive symptoms, are potential risk factors.