Relationship between residual kidney function and symptom burden in haemodialysis patients

Residual kidney function (RKF) has been associated with improved solute clearance and survival in haemodialysis (HD) patients. However, whether RKF impacts symptom burden in HD patients is unknown.

To determine the prevalence of RKF in HD patients and to explore associations between higher levels of RKF with symptom burden, as well as clinical and biochemical parameters.

This is a single-centre, retrospective, observational study. RKF was assessed as urea clearance (KRU) by interdialytic urine collection. Symptom burden was measured using the palliative care outcome scale renal questionnaire.

A total of 90 maintenance HD patients was recruited; 31.9% had KRU ≥1 mL/min/1.73 m² . Patients with KRU ≥1 mL/min/1.73 m² reported fewer symptoms (5.3 ± 3.5 vs 7.7 ± 3.8) (P = 0.011), including less shortness of breath (15% vs 55%) (P = 0.0013) and vomiting (0% vs 30%) (P = 0.0016). Higher RKF was associated with lower β₂ -microglobilin (P < 0.0001), and lower serum potassium (P = 0.02), but no difference in phosphate, haemoglobin, C-reactive protein or serum albumin.

Higher RKF was significantly associated with fewer symptoms, and lower serum β₂ -microglobulin and potassium, suggesting that strategies to preserve RKF may be beneficial.