#4268 RELATIONSHIP BETWEEN MEASURED SLEEP QUALITY AND CLINICAL PARAMETERS IN DIALYSIS PATIENTS
Authors: Butt Usama , Vilar Enric , Sridharan Sivakumar , Farrington Kenneth , Berdeprado Jocelyn 
Published: June 2023

Abstract

Background and Aims
Poor sleep quality in dialysis patients has been well reported and has deleterious effects on quality of life. Factors affecting the sleep quality in these patients have not been very well explored. Actigraphy using wearable devices with 3D accelerometers is a well-recognised method of analysing the sleep quality. We set out to determine the relationship of sleep quality parameters measured using actigraphy with dialysis related factors in patients on dialysis.

Method
We conducted a prospective analysis of 95 patients, involving 75 In Centre Haemodialysis (ICHD), 15 Home Haemodialysis (HHD) and 8 Peritoneal dialysis (PD) patients. Sleep data was collected using Actigraph wrist device. Participants were instructed to wear the device 24 hours a day for consecutive 7 days. Sleep data analysis was conducted with Actilife software using Cole-Kripke sleep-wake algorithm. Sleep quality parameters used for assessment included Sleep Efficiency, Average Total sleep time (TST), Wake after sleep onset (WASO), Number of Awakenings, Sleep Fragmentation index. All of these are well recognised sleep quality parameters. Demographic and clinical information was collected prospectively from medical records.

Results
Our study cohort was well representative of general dialysis population. Median Age was 65 years, with 65.6% Males and 34.4% Females. All sleep quality parameters were considerably poor compared to age matched general population. Mean Sleep Efficiency was 77.5% (Normal for age matched general population is 83.2%), Mean TST was 318 minutes (Normal 372 minutes), Mean WASO was 83 minutes (Normal 64 minutes), Mean Sleep Fragmentation index was 43. None of the sleep quality parameters had significant difference in different dialysis modalities in our study. Amongst the predictors of sleep quality, serum phosphate had significant association with increased WASO (p = 0.002). Mean WASO was 99 minutes for patients with serum Phosphate &gt; 1.8 mmol/L compared to 74 minutes for those with serum phosphate of &lt; 1.8 mmol/L. Serum phosphate had a borderline significant positive correlation with Number of Awakenings (p = 0.06) and borderline significant negative correlation with Sleep Efficiency (p = 0.06). Renal urea clearance (KRU) had statistically significant positive correlation with sleep efficiency (p = 0.013) but didn’t reach statistical significance in relation to the other sleep quality parameters. Urine volume also had positive correlation with sleep efficiency nearly reaching statistical significance (p = 0.055). Other factors analysed during the study didn’t appear to have any significant associations with sleep quality.

Conclusion
Actigraphy is non-invasive, less cumbersome, and reliable method of sleep assessment in dialysis patients. Compared to the age matched general population, dialysis patients have objectively measured poor sleep quality. Serum phosphate has significant negative impact on sleep quality possibly secondary to hyperphosphatemia-related side effects. Residual kidney function has positive association with sleep efficiency. This study highlights the potential importance of preserving residual kidney functions and treating hyperphosphatemia in dialysis patients which warrants further research.