Pruritus Linked to Increased Risk of Depression, Restlessness in CKD Patients

Nidhi Sukul, MD

Credit: University of Michigan

A recent longitudinal study of nearly 8,000 patients across 21 countries highlights the negative impacts of chronic kidney disease-associated pruritus (CKD-aP) on individuals receiving hemodialysis treatment, calling attention to the need for regular pruritus testing and treatment assessment.

“This international study is the largest of its kind to evaluate the longitudinal course of pruritus and its associated outcomes. Providers often underestimate the prevalence of pruritus,” said lead investigator Nidhi Sukul, MD, assistant chief of the Renal Section at the Veterans Affairs Ann Arbor Health Care System and assistant professor in the Division of Nephrology at the University of Michigan. “Given the study findings, patients undergoing hemodialysis should have regular assessment of pruritus and be evaluated for treatment.”²

CKD is highly prevalent in the US, with 37 million adults estimated to have kidney disease and approximately 1 in 3 adults being at risk for kidney disease. Pruritus is a common and bothersome side effect for many CKD patients being treated with hemodialysis.²

Investigators aimed to build upon cross-sectional study reports of an association of CKD-aP with adverse clinical events and patient-reported outcomes (PROs) by further examining longitudinal associations among patients receiving maintenance hemodialysis.¹

The current study used data obtained from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective cohort study of adults receiving in-center hemodialysis who were randomly selected from facilities across 21 countries and given 2 pruritus assessments over the course of one year. In total, investigators identified 7976 patients who had pruritus information at both assessments.¹

These patients were grouped into 4 categories based on whether they were at least moderately bothered by itchy skin at their initial assessment and the follow-up assessment. These were classified as persistent (Yes/Yes), resolved (Yes/No), incident (No/Yes), and absent (No/No) based on having a Yes/Yes, Yes/No, No/Yes, and No/No responses, respectively. Overall, 51% of the patients were at least moderately bothered by itchy skin at the initial assessment or follow-up assessment, including 22% reporting itchy skin at both. Investigators also pointed out 44% of patients reported the same CKD-aP severity at both assessments. In contrast, 28% experienced improvement and 28% experienced worsening.¹

For the purpose of analysis, investigators used a linear mixed model to investigate changes in laboratory values and PROs during the study period. Of note, all models were adjusted for patient age, sex, and baseline covariates of BMI, dialysis vintage, 13 classes of comorbidity, serum albumin, hemoglobin, serum phosphorus, single pool Kt/V, and catheter as dialysis access.¹

PROs tracked closely with changes in CKD-aP. Upon analysis, an increased prevalence of depression (+13%), restless sleep (+10%), and feeling drained (+14%) was observed among those with incident CKD-aP during the study period, while those with resolved pruritus experienced decreases in incidence of each (-5%, -8%, and -12%, respectively).¹

Further analysis indicated no changes over time in laboratory values were observed for either group. Investigators highlighted those with CKD-aP were at a 29% greater risk of all-cause mortality (adjusted hazard ratio [aHR], 1.29; 95% confidence interval [CI], 1.09 to 1.53), 17% (aHR, 1.17; 95% CI, 1.07 to 1.28) greater risk of all-cause hospitalization, and 48% (aHR, 1.48; 95% CI, 1.26 to 1.74) greater risk of cardiovascular events.¹

“The high prevalence and far-reaching negative effects of CKD-aP makes it prudent to enhance the knowledge surrounding the course of pruritus and how the chronicity of this debilitating symptom affects varied aspects of patients’ lives,” wrote investigators.¹

References

1. Sukul N, Zhao J, Pisoni RL, et al. Pruritus in hemodialysis patients: Longitudinal associations with clinical and patient-reported outcomes. American Journal of Kidney Diseases. Published online 2023. doi:10.1053/j.ajkd.2023.04.008
2. Chronic itching worsens fatigue and reduces quality of life in 50% of hemodialysis patients. National Kidney Foundation. August 16, 2023. https://www.kidney.org/news/chronic-itching-worsens-fatigue-and-reduces-quality-life-50-hemodialysis-patients.