Does Ultrafiltration Rate Influence Sleep Quality among Hemodialysis Patients?

Sleep disturbances are common in hemodialysis (HD) patients. We examined the excessive ultrafiltration rate (UFR), which is associated with poor outcomes, for its possible impact on sleep quality.

Only oligo-anuric patients with a three-times-weekly HD schedule were included in the study. Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality and a score >5 indicated poor sleepers. Ultrafiltration values refer to the month preceding the PSQI survey. Patients were divided into three categories: optimal UFR group (<10 mL/kg/h), borderline UFR group (10-13 mL/kg/h), and high UFR group (≥13 mL/kg/h).

A total of 102 patients were included, with a median age of 60 (46-67) years. Median dialysis vintage was 44.5 (22-77) months. Average interdialytic weight gain (IDWG) percentage was 4.7 (3.7-5.7) and UFR was 11.6 ± 3.5 mL/kg/h. A total of 37 patients (36.3%) had optimal UFR, 29 patients (28.4%) had borderline UFR, and 36 patients (35.3%) had high UFR. Average PSQI score was 7 (4-10) points and 61 patients (59.8%) was identified as poor sleepers. Mean UFR was 11.7 ± 3.4 mL/kg/h in poor sleepers and 11.5 ± 3.7 mL/kg/h in non-poor sleepers (p = 0.819). PSQI score and poor sleeper prevalence were not significantly different between UFR groups. There was no significant correlation between PSQI and UFR (p = 0.325). In multivariate regression analysis, UFR was not an independent predictor of sleep quality. Additionally, younger age and a long HD vintage were independent predictors of high UFR.

Excessive and rapid fluid removal does not constitute a risk for poor sleep quality. Also, current findings underscore the increased frequency and complexity of sleep disorders in dialysis patients.