Patients with chronic kidney disease (CKD) experience uremic symptoms, including pruritus. Uremic symptoms are major contributors to symptom burden in patients with CKD and are associated with decreased quality of life. However, according to Kendra E. Wulczyn, MD, and colleagues, there are few data available on the factors associated with progression of uremic symptoms in patients with CKD.

The researchers analyzed data from 3504 participants with CKD not on dialysis in the CRIC (Chronic Renal Insufficiency Cohort) study. Results were reported during a virtual poster session at AKF Kidney Week 2021 in a poster titled Subtle Changes in Uremic Symptoms with CKD Progression.

Eligible patients had at least two assessments of estimated glomerular filtration rate (eGFR) and uremic symptoms. The Kidney Disease Quality of Life instrument was used to annually assess uremic symptoms of pruritus, fatigue, and anorexia. Responses were transformed to a scale from zero to 100, with lower scores indicating worse symptom severity. The association between change in eGFR and the change in uremic symptoms over time was estimated using multivariate linear mixed effects models with random intercepts and random slopes.

Of the total cohort, mean age was 58 years, 45% were women, 41% were Black, and mean eGFR at baseline was 45 mL/min/1.73 m2. Median follow-up was 7 years (IQR 3-11). During follow-up, the average annual decline in eGFR was -1.3 mL/min/1.73 m2 per year. The average annual change in symptom scores for pruritis were -0.49 (95% confidence interval [CI], ­-0.59 to -0.39); for fatigue, -0.27 (95% CI, -0.35 to  -0.19); and for anorexia, -0.26 (95% CI, -0.33 to -0.19).

There was a significant association between a 10-unit change in eGFR and worsening pruritus, fatigue, and anorexia. The association was stronger for patients with eGFR <30 mL/min/1.732 compared with patients with higher eGFR.

In conclusion, the researchers said, “Decreasing kidney function is associated with worsening fatigue, anorexia, and pruritus; however, the absolute change in symptom severity scores is small and unlikely to be clinically meaningful. Regular symptom assessment should be incorporated into routine CKD care; however, caution should be used when attributing large changes in symptom solely to changes in the level of kidney function.”